powercap / RAPL: disable the 2nd power limit properly #1

sikarash · 2015-08-27T08:33:16Z

Let rapl_unregister_powercap() disable the second power limit
only if it exists.
Intel64 SDM Vol.3 14.9 says that the package domain has it
but neither the power plane domain nor the DRAM domain has it.

Signed-off-by: Seiichi Ikarashi s.ikarashi@jp.fujitsu.com

Let rapl_unregister_powercap() disable the second power limit only if it exists. Intel64 SDM Vol.3 14.9 says that the package domain has it but neither the power plane domain nor the DRAM domain has it. Signed-off-by: Seiichi Ikarashi <s.ikarashi@jp.fujitsu.com>

Hit the following splat testing VRF change for ipsec: [ 113.475692] =============================== [ 113.476194] [ INFO: suspicious RCU usage. ] [ 113.476667] 4.2.0-rc6-1+deb7u2+clUNRELEASED #3.2.65-1+deb7u2+clUNRELEASED Not tainted [ 113.477545] ------------------------------- [ 113.478013] /work/monster-14/dsa/kernel.git/include/linux/rcupdate.h:568 Illegal context switch in RCU read-side critical section! [ 113.479288] [ 113.479288] other info that might help us debug this: [ 113.479288] [ 113.480207] [ 113.480207] rcu_scheduler_active = 1, debug_locks = 1 [ 113.480931] 2 locks held by setkey/6829: [ 113.481371] #0: (&net->xfrm.xfrm_cfg_mutex){+.+.+.}, at: [<ffffffff814e9887>] pfkey_sendmsg+0xfb/0x213 [ 113.482509] #1: (rcu_read_lock){......}, at: [<ffffffff814e767f>] rcu_read_lock+0x0/0x6e [ 113.483509] [ 113.483509] stack backtrace: [ 113.484041] CPU: 0 PID: 6829 Comm: setkey Not tainted 4.2.0-rc6-1+deb7u2+clUNRELEASED #3.2.65-1+deb7u2+clUNRELEASED [ 113.485422] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5.1-0-g8936dbb-20141113_115728-nilsson.home.kraxel.org 04/01/2014 [ 113.486845] 0000000000000001 ffff88001d4c7a98 ffffffff81518af2 ffffffff81086962 [ 113.487732] ffff88001d538480 ffff88001d4c7ac8 ffffffff8107ae75 ffffffff8180a154 [ 113.488628] 0000000000000b30 0000000000000000 00000000000000d0 ffff88001d4c7ad8 [ 113.489525] Call Trace: [ 113.489813] [<ffffffff81518af2>] dump_stack+0x4c/0x65 [ 113.490389] [<ffffffff81086962>] ? console_unlock+0x3d6/0x405 [ 113.491039] [<ffffffff8107ae75>] lockdep_rcu_suspicious+0xfa/0x103 [ 113.491735] [<ffffffff81064032>] rcu_preempt_sleep_check+0x45/0x47 [ 113.492442] [<ffffffff8106404d>] ___might_sleep+0x19/0x1c8 [ 113.493077] [<ffffffff81064268>] __might_sleep+0x6c/0x82 [ 113.493681] [<ffffffff81133190>] cache_alloc_debugcheck_before.isra.50+0x1d/0x24 [ 113.494508] [<ffffffff81134876>] kmem_cache_alloc+0x31/0x18f [ 113.495149] [<ffffffff814012b5>] skb_clone+0x64/0x80 [ 113.495712] [<ffffffff814e6f71>] pfkey_broadcast_one+0x3d/0xff [ 113.496380] [<ffffffff814e7b84>] pfkey_broadcast+0xb5/0x11e [ 113.497024] [<ffffffff814e82d1>] pfkey_register+0x191/0x1b1 [ 113.497653] [<ffffffff814e9770>] pfkey_process+0x162/0x17e [ 113.498274] [<ffffffff814e9895>] pfkey_sendmsg+0x109/0x213 In pfkey_sendmsg the net mutex is taken and then pfkey_broadcast takes the RCU lock. Since pfkey_broadcast takes the RCU lock the allocation argument is pointless since GFP_ATOMIC must be used between the rcu_read_{,un}lock. The one call outside of rcu can be done with GFP_KERNEL. Fixes: 7f6b9db ("af_key: locking change") Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>

[ 1065.801569] Internal error: Oops: 96000006 [#1] SMP ... [ 1065.866655] Hardware name: AppliedMicro Mustang/Mustang, BIOS 1.1.0 Apr 22 2015 [ 1065.873937] Workqueue: events_power_efficient phy_state_machine [ 1065.879837] task: fffffe01de105e80 ti: fffffe00bcf18000 task.ti: fffffe00bcf18000 [ 1065.887288] PC is at linkwatch_fire_event+0xac/0xc0 [ 1065.892141] LR is at linkwatch_fire_event+0xa0/0xc0 [ 1065.896995] pc : [<fffffe000060284c>] lr : [<fffffe0000602840>] pstate: 200001c5 [ 1065.904356] sp : fffffe00bcf1bd00 ... [ 1066.196813] Call Trace: [ 1066.199248] [<fffffe000060284c>] linkwatch_fire_event+0xac/0xc0 [ 1066.205140] [<fffffe000061167c>] netif_carrier_off+0x54/0x64 [ 1066.210773] [<fffffe00004f1654>] phy_state_machine+0x120/0x3bc [ 1066.216578] [<fffffe00000d8d10>] process_one_work+0x15c/0x3a8 [ 1066.222296] [<fffffe00000d9090>] worker_thread+0x134/0x470 [ 1066.227757] [<fffffe00000df014>] kthread+0xe0/0xf8 [ 1066.232525] Code: 97f65ee9 f9420660 d538d082 8b000042 (885f7c40) The fix is to call phy_disconnect() from xgene_enet_mdio_remove, which in turn call cancel_delayed_work_sync(). Signed-off-by: Iyappan Subramanian <isubramanian@apm.com> Signed-off-by: David S. Miller <davem@davemloft.net>

This reverts commit 2143c19. This commit seems to be the cause of the following jbd2 assertion failure: ------------[ cut here ]------------ kernel BUG at fs/jbd2/transaction.c:1325! invalid opcode: 0000 [#1] SMP Modules linked in: bnep bluetooth fuse ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 ... CPU: 7 PID: 5509 Comm: gcc Not tainted 4.1.0-10944-g2a298679b411 #1 Hardware name: /DH87RL, BIOS RLH8710H.86A.0327.2014.0924.1645 09/24/2014 task: ffff8803bf866040 ti: ffff880308528000 task.ti: ffff880308528000 RIP: jbd2_journal_dirty_metadata+0x237/0x290 Call Trace: __ext4_handle_dirty_metadata+0x43/0x1f0 ext4_handle_dirty_dirent_node+0xde/0x160 ? jbd2_journal_get_write_access+0x36/0x50 ext4_delete_entry+0x112/0x160 ? __ext4_journal_start_sb+0x52/0xb0 ext4_unlink+0xfa/0x260 vfs_unlink+0xec/0x190 do_unlinkat+0x24a/0x270 SyS_unlink+0x11/0x20 entry_SYSCALL_64_fastpath+0x12/0x6a ---[ end trace ae033ebde8d080b4 ]--- which is not easily reproducible (I've seen it just once, and then Ted was able to reproduce it once). Revert it while Ted and Jan try to figure out what is wrong. Cc: Jan Kara <jack@suse.cz> Acked-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The following lockdep splat was seen due to the wrong context for grabbing in_dev. =============================== [ INFO: suspicious RCU usage. ] 4.1.0-next-20150626-dbg-00020-g54a6d91-dirty torvalds#244 Not tainted ------------------------------- include/linux/inetdevice.h:205 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 2 locks held by ip/403: #0: (rtnl_mutex){+.+.+.}, at: [<ffffffff81453305>] rtnl_lock+0x17/0x19 #1: ((inetaddr_chain).rwsem){.+.+.+}, at: [<ffffffff8105c327>] __blocking_notifier_call_chain+0x35/0x6a stack backtrace: CPU: 2 PID: 403 Comm: ip Not tainted 4.1.0-next-20150626-dbg-00020-g54a6d91-dirty torvalds#244 0000000000000001 ffff8800b189b728 ffffffff8150a542 ffffffff8107a8b3 ffff880037bbea40 ffff8800b189b758 ffffffff8107cb74 ffff8800379dbd00 ffff8800bec85800 ffff8800bf9e13c0 00000000000000ff ffff8800b189b7d8 Call Trace: [<ffffffff8150a542>] dump_stack+0x4c/0x6e [<ffffffff8107a8b3>] ? up+0x39/0x3e [<ffffffff8107cb74>] lockdep_rcu_suspicious+0xf7/0x100 [<ffffffff814b63c3>] fib_dump_info+0x227/0x3e2 [<ffffffff814b6624>] rtmsg_fib+0xa6/0x116 [<ffffffff814b978f>] fib_table_insert+0x316/0x355 [<ffffffff814b362e>] fib_magic+0xb7/0xc7 [<ffffffff814b4803>] fib_add_ifaddr+0xb1/0x13b [<ffffffff814b4d09>] fib_inetaddr_event+0x36/0x90 [<ffffffff8105c086>] notifier_call_chain+0x4c/0x71 [<ffffffff8105c340>] __blocking_notifier_call_chain+0x4e/0x6a [<ffffffff8105c370>] blocking_notifier_call_chain+0x14/0x16 [<ffffffff814a7f50>] __inet_insert_ifa+0x1a5/0x1b3 [<ffffffff814a894d>] inet_rtm_newaddr+0x350/0x35f [<ffffffff81457866>] rtnetlink_rcv_msg+0x17b/0x18a [<ffffffff8107e7c3>] ? trace_hardirqs_on+0xd/0xf [<ffffffff8146965f>] ? netlink_deliver_tap+0x1cb/0x1f7 [<ffffffff814576eb>] ? rtnl_newlink+0x72a/0x72a ... This patch resolves that splat. Signed-off-by: Andy Gospodarek <gospo@cumulusnetworks.com> Reported-by: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>

There is NULL pointer dereference possible during statistics update if the route used for OOTB responce is removed at unfortunate time. If the route exists when we receive OOTB packet and we finally jump into sctp_packet_transmit() to send ABORT, but in the meantime route is removed under our feet, we take "no_route" path and try to update stats with IP_INC_STATS(sock_net(asoc->base.sk), ...). But sctp_ootb_pkt_new() used to prepare responce packet doesn't call sctp_transport_set_owner() and therefore there is no asoc associated with this packet. Probably temporary asoc just for OOTB responces is overkill, so just introduce a check like in all other places in sctp_packet_transmit(), where "asoc" is dereferenced. To reproduce this, one needs to 0. ensure that sctp module is loaded (otherwise ABORT is not generated) 1. remove default route on the machine 2. while true; do ip route del [interface-specific route] ip route add [interface-specific route] done 3. send enough OOTB packets (i.e. HB REQs) from another host to trigger ABORT responce On x86_64 the crash looks like this: BUG: unable to handle kernel NULL pointer dereference at 0000000000000020 IP: [<ffffffffa05ec9ac>] sctp_packet_transmit+0x63c/0x730 [sctp] PGD 0 Oops: 0000 [#1] PREEMPT SMP Modules linked in: ... CPU: 0 PID: 0 Comm: swapper/0 Tainted: G O 4.0.5-1-ARCH #1 Hardware name: ... task: ffffffff818124c0 ti: ffffffff81800000 task.ti: ffffffff81800000 RIP: 0010:[<ffffffffa05ec9ac>] [<ffffffffa05ec9ac>] sctp_packet_transmit+0x63c/0x730 [sctp] RSP: 0018:ffff880127c037b8 EFLAGS: 00010296 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00000015ff66b480 RDX: 00000015ff66b400 RSI: ffff880127c17200 RDI: ffff880123403700 RBP: ffff880127c03888 R08: 0000000000017200 R09: ffffffff814625af R10: ffffea00047e4680 R11: 00000000ffffff80 R12: ffff8800b0d38a28 R13: ffff8800b0d38a28 R14: ffff8800b3e88000 R15: ffffffffa05f24e0 FS: 0000000000000000(0000) GS:ffff880127c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000020 CR3: 00000000c855b000 CR4: 00000000000007f0 Stack: ffff880127c03910 ffff8800b0d38a28 ffffffff8189d240 ffff88011f91b400 ffff880127c03828 ffffffffa05c94c5 0000000000000000 ffff8800baa1c520 0000000000000000 0000000000000001 0000000000000000 0000000000000000 Call Trace: <IRQ> [<ffffffffa05c94c5>] ? sctp_sf_tabort_8_4_8.isra.20+0x85/0x140 [sctp] [<ffffffffa05d6b42>] ? sctp_transport_put+0x52/0x80 [sctp] [<ffffffffa05d0bfc>] sctp_do_sm+0xb8c/0x19a0 [sctp] [<ffffffff810b0e00>] ? trigger_load_balance+0x90/0x210 [<ffffffff810e0329>] ? update_process_times+0x59/0x60 [<ffffffff812c7a40>] ? timerqueue_add+0x60/0xb0 [<ffffffff810e0549>] ? enqueue_hrtimer+0x29/0xa0 [<ffffffff8101f599>] ? read_tsc+0x9/0x10 [<ffffffff8116d4b5>] ? put_page+0x55/0x60 [<ffffffff810ee1ad>] ? clockevents_program_event+0x6d/0x100 [<ffffffff81462b68>] ? skb_free_head+0x58/0x80 [<ffffffffa029a10b>] ? chksum_update+0x1b/0x27 [crc32c_generic] [<ffffffff81283f3e>] ? crypto_shash_update+0xce/0xf0 [<ffffffffa05d3993>] sctp_endpoint_bh_rcv+0x113/0x280 [sctp] [<ffffffffa05dd4e6>] sctp_inq_push+0x46/0x60 [sctp] [<ffffffffa05ed7a0>] sctp_rcv+0x880/0x910 [sctp] [<ffffffffa05ecb50>] ? sctp_packet_transmit_chunk+0xb0/0xb0 [sctp] [<ffffffffa05ecb70>] ? sctp_csum_update+0x20/0x20 [sctp] [<ffffffff814b05a5>] ? ip_route_input_noref+0x235/0xd30 [<ffffffff81051d6b>] ? ack_ioapic_level+0x7b/0x150 [<ffffffff814b27be>] ip_local_deliver_finish+0xae/0x210 [<ffffffff814b2e15>] ip_local_deliver+0x35/0x90 [<ffffffff814b2a15>] ip_rcv_finish+0xf5/0x370 [<ffffffff814b3128>] ip_rcv+0x2b8/0x3a0 [<ffffffff81474193>] __netif_receive_skb_core+0x763/0xa50 [<ffffffff81476c28>] __netif_receive_skb+0x18/0x60 [<ffffffff81476cb0>] netif_receive_skb_internal+0x40/0xd0 [<ffffffff814776c8>] napi_gro_receive+0xe8/0x120 [<ffffffffa03946aa>] rtl8169_poll+0x2da/0x660 [r8169] [<ffffffff8147896a>] net_rx_action+0x21a/0x360 [<ffffffff81078dc1>] __do_softirq+0xe1/0x2d0 [<ffffffff8107912d>] irq_exit+0xad/0xb0 [<ffffffff8157d158>] do_IRQ+0x58/0xf0 [<ffffffff8157b06d>] common_interrupt+0x6d/0x6d <EOI> [<ffffffff810e1218>] ? hrtimer_start+0x18/0x20 [<ffffffffa05d65f9>] ? sctp_transport_destroy_rcu+0x29/0x30 [sctp] [<ffffffff81020c50>] ? mwait_idle+0x60/0xa0 [<ffffffff810216ef>] arch_cpu_idle+0xf/0x20 [<ffffffff810b731c>] cpu_startup_entry+0x3ec/0x480 [<ffffffff8156b365>] rest_init+0x85/0x90 [<ffffffff818eb035>] start_kernel+0x48b/0x4ac [<ffffffff818ea120>] ? early_idt_handlers+0x120/0x120 [<ffffffff818ea339>] x86_64_start_reservations+0x2a/0x2c [<ffffffff818ea49c>] x86_64_start_kernel+0x161/0x184 Code: 90 48 8b 80 b8 00 00 00 48 89 85 70 ff ff ff 48 83 bd 70 ff ff ff 00 0f 85 cd fa ff ff 48 89 df 31 db e8 18 63 e7 e0 48 8b 45 80 <48> 8b 40 20 48 8b 40 30 48 8b 80 68 01 00 00 65 48 ff 40 78 e9 RIP [<ffffffffa05ec9ac>] sctp_packet_transmit+0x63c/0x730 [sctp] RSP <ffff880127c037b8> CR2: 0000000000000020 ---[ end trace 5aec7fd2dc983574 ]--- Kernel panic - not syncing: Fatal exception in interrupt Kernel Offset: 0x0 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffff9fffffff) drm_kms_helper: panic occurred, switching back to text console ---[ end Kernel panic - not syncing: Fatal exception in interrupt Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>

Kernel sockets do not hold a reference for the network namespace to which they point. Socket destruction broadcasting relies on the network namespace and will cause the splat below when a kernel socket is destroyed. This fix simply ignores kernel sockets when they are destroyed. Reported as: general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC CPU: 1 PID: 9130 Comm: kworker/1:1 Not tainted 4.1.0-gelk-debug+ #1 Workqueue: sock_diag_events sock_diag_broadcast_destroy_work Stack: ffff8800b9c586c0 ffff8800b9c586c0 ffff8800ac4692c0 ffff8800936d4a90 ffff8800352efd38 ffffffff8469a93e ffff8800352efd98 ffffffffc09b9b90 ffff8800352efd78 ffff8800ac4692c0 ffff8800b9c586c0 ffff8800831b6ab8 Call Trace: [<ffffffff8469a93e>] ? mutex_unlock+0xe/0x10 [<ffffffffc09b9b90>] ? inet_diag_handler_get_info+0x110/0x1fb [inet_diag] [<ffffffff845c868d>] netlink_broadcast+0x1d/0x20 [<ffffffff8469a93e>] ? mutex_unlock+0xe/0x10 [<ffffffff845b2bf5>] sock_diag_broadcast_destroy_work+0xd5/0x160 [<ffffffff8408ea97>] process_one_work+0x147/0x420 [<ffffffff8408f0f9>] worker_thread+0x69/0x470 [<ffffffff8409fda3>] ? preempt_count_sub+0xa3/0xf0 [<ffffffff8408f090>] ? rescuer_thread+0x320/0x320 [<ffffffff84093cd7>] kthread+0x107/0x120 [<ffffffff84093bd0>] ? kthread_create_on_node+0x1b0/0x1b0 [<ffffffff8469d31f>] ret_from_fork+0x3f/0x70 [<ffffffff84093bd0>] ? kthread_create_on_node+0x1b0/0x1b0 Tested: Using a debug kernel while 'ss -E' is running: ip netns add test-ns ip netns delete test-ns Fixes: eb4cb00 sock_diag: define destruction multicast groups Fixes: 26abe14 net: Modify sk_alloc to not reference count the netns of kernel sockets. Reported-by: Dave Jones <davej@codemonkey.org.uk> Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Craig Gallek <kraig@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>

We have a race between deleting an unused block group and balancing the same block group that leads to an assertion failure/BUG(), producing the following trace: [181631.208236] BTRFS: assertion failed: 0, file: fs/btrfs/volumes.c, line: 2622 [181631.220591] ------------[ cut here ]------------ [181631.222959] kernel BUG at fs/btrfs/ctree.h:4062! [181631.223932] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC [181631.224566] Modules linked in: btrfs dm_flakey dm_mod crc32c_generic xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc loop fuse acpi_cpufreq parpor$ [181631.224566] CPU: 8 PID: 17451 Comm: btrfs Tainted: G W 4.1.0-rc5-btrfs-next-10+ #1 [181631.224566] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20150316_085822-nilsson.home.kraxel.org 04/01/2014 [181631.224566] task: ffff880127e09590 ti: ffff8800b5824000 task.ti: ffff8800b5824000 [181631.224566] RIP: 0010:[<ffffffffa03f19f6>] [<ffffffffa03f19f6>] assfail.constprop.50+0x1e/0x20 [btrfs] [181631.224566] RSP: 0018:ffff8800b5827ae8 EFLAGS: 00010246 [181631.224566] RAX: 0000000000000040 RBX: ffff8800109fc218 RCX: ffffffff81095dce [181631.224566] RDX: 0000000000005124 RSI: ffffffff81464819 RDI: 00000000ffffffff [181631.224566] RBP: ffff8800b5827ae8 R08: 0000000000000001 R09: 0000000000000000 [181631.224566] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8800109fc200 [181631.224566] R13: ffff880020095000 R14: ffff8800b1a13f38 R15: ffff880020095000 [181631.224566] FS: 00007f70ca0b0c80(0000) GS:ffff88013ec00000(0000) knlGS:0000000000000000 [181631.224566] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [181631.224566] CR2: 00007f2872ab6e68 CR3: 00000000a717c000 CR4: 00000000000006e0 [181631.224566] Stack: [181631.224566] ffff8800b5827ba8 ffffffffa03f3916 ffff8800b5827b38 ffffffffa03d080e [181631.224566] ffffffffa03d1423 ffff880020095000 ffff88001233c000 0000000000000001 [181631.224566] ffff880020095000 ffff8800b1a13f38 0000000a69c00000 0000000000000000 [181631.224566] Call Trace: [181631.224566] [<ffffffffa03f3916>] btrfs_remove_chunk+0xa4/0x6bb [btrfs] [181631.224566] [<ffffffffa03d080e>] ? join_transaction.isra.8+0xb9/0x3ba [btrfs] [181631.224566] [<ffffffffa03d1423>] ? wait_current_trans.isra.13+0x22/0xfc [btrfs] [181631.224566] [<ffffffffa03f3fbc>] btrfs_relocate_chunk.isra.29+0x8f/0xa7 [btrfs] [181631.224566] [<ffffffffa03f54df>] btrfs_balance+0xaa4/0xc52 [btrfs] [181631.224566] [<ffffffffa03fd388>] btrfs_ioctl_balance+0x23f/0x2b0 [btrfs] [181631.224566] [<ffffffff810872f9>] ? trace_hardirqs_on+0xd/0xf [181631.224566] [<ffffffffa04019a3>] btrfs_ioctl+0xfe2/0x2220 [btrfs] [181631.224566] [<ffffffff812603ed>] ? __this_cpu_preempt_check+0x13/0x15 [181631.224566] [<ffffffff81084669>] ? arch_local_irq_save+0x9/0xc [181631.224566] [<ffffffff81138def>] ? handle_mm_fault+0x834/0xcd2 [181631.224566] [<ffffffff81138def>] ? handle_mm_fault+0x834/0xcd2 [181631.224566] [<ffffffff8103e48c>] ? __do_page_fault+0x211/0x424 [181631.224566] [<ffffffff811755e6>] do_vfs_ioctl+0x3c6/0x479 (...) The sequence of steps leading to this are: CPU 0 CPU 1 btrfs_balance() btrfs_relocate_chunk() btrfs_relocate_block_group(bg X) btrfs_lookup_block_group(bg X) cleaner_kthread locks fs_info->cleaner_mutex btrfs_delete_unused_bgs() finds bg X, which became unused in the previous transaction checks bg X ->ro == 0, so it proceeds sets bg X ->ro to 1 (btrfs_set_block_group_ro(bg X)) blocks on fs_info->cleaner_mutex btrfs_remove_chunk(bg X) unlocks fs_info->cleaner_mutex acquires fs_info->cleaner_mutex relocate_block_group() --> does nothing, no extents found in the extent tree from bg X unlocks fs_info->cleaner_mutex btrfs_relocate_block_group(bg X) returns btrfs_remove_chunk(bg X) extent map not found --> ASSERT(0) Fix this by using a new mutex to make sure these 2 operations, block group relocation and removal, are serialized. This issue is reproducible by running fstests generic/038 (which stresses chunk allocation and automatic removal of unused block groups) together with the following balance loop: while true; do btrfs balance start -dusage=0 <mountpoint> ; done Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>

…cache While the inode cache caching kthread is calling btrfs_unpin_free_ino(), we could have a concurrent call to btrfs_return_ino() that adds a new entry to the root's free space cache of pinned inodes. This concurrent call does not acquire the fs_info->commit_root_sem before adding a new entry if the caching state is BTRFS_CACHE_FINISHED, which is a problem because the caching kthread calls btrfs_unpin_free_ino() after setting the caching state to BTRFS_CACHE_FINISHED and therefore races with the task calling btrfs_return_ino(), which is adding a new entry, while the former (caching kthread) is navigating the cache's rbtree, removing and freeing nodes from the cache's rbtree without acquiring the spinlock that protects the rbtree. This race resulted in memory corruption due to double free of struct btrfs_free_space objects because both tasks can end up doing freeing the same objects. Note that adding a new entry can result in merging it with other entries in the cache, in which case those entries are freed. This is particularly important as btrfs_free_space structures are also used for the block group free space caches. This memory corruption can be detected by a debugging kernel, which reports it with the following trace: [132408.501148] slab error in verify_redzone_free(): cache `btrfs_free_space': double free detected [132408.505075] CPU: 15 PID: 12248 Comm: btrfs-ino-cache Tainted: G W 4.1.0-rc5-btrfs-next-10+ #1 [132408.505075] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20150316_085822-nilsson.home.kraxel.org 04/01/2014 [132408.505075] ffff880023e7d320 ffff880163d73cd8 ffffffff8145eec7 ffffffff81095dce [132408.505075] ffff880009735d40 ffff880163d73ce8 ffffffff81154e1e ffff880163d73d68 [132408.505075] ffffffff81155733 ffffffffa054a95a ffff8801b6099f00 ffffffffa0505b5f [132408.505075] Call Trace: [132408.505075] [<ffffffff8145eec7>] dump_stack+0x4f/0x7b [132408.505075] [<ffffffff81095dce>] ? console_unlock+0x356/0x3a2 [132408.505075] [<ffffffff81154e1e>] __slab_error.isra.28+0x25/0x36 [132408.505075] [<ffffffff81155733>] __cache_free+0xe2/0x4b6 [132408.505075] [<ffffffffa054a95a>] ? __btrfs_add_free_space+0x2f0/0x343 [btrfs] [132408.505075] [<ffffffffa0505b5f>] ? btrfs_unpin_free_ino+0x8e/0x99 [btrfs] [132408.505075] [<ffffffff810f3b30>] ? time_hardirqs_off+0x15/0x28 [132408.505075] [<ffffffff81084d42>] ? trace_hardirqs_off+0xd/0xf [132408.505075] [<ffffffff811563a1>] ? kfree+0xb6/0x14e [132408.505075] [<ffffffff811563d0>] kfree+0xe5/0x14e [132408.505075] [<ffffffffa0505b5f>] btrfs_unpin_free_ino+0x8e/0x99 [btrfs] [132408.505075] [<ffffffffa0505e08>] caching_kthread+0x29e/0x2d9 [btrfs] [132408.505075] [<ffffffffa0505b6a>] ? btrfs_unpin_free_ino+0x99/0x99 [btrfs] [132408.505075] [<ffffffff8106698f>] kthread+0xef/0xf7 [132408.505075] [<ffffffff810f3b08>] ? time_hardirqs_on+0x15/0x28 [132408.505075] [<ffffffff810668a0>] ? __kthread_parkme+0xad/0xad [132408.505075] [<ffffffff814653d2>] ret_from_fork+0x42/0x70 [132408.505075] [<ffffffff810668a0>] ? __kthread_parkme+0xad/0xad [132408.505075] ffff880023e7d320: redzone 1:0x9f911029d74e35b, redzone 2:0x9f911029d74e35b. [132409.501654] slab: double free detected in cache 'btrfs_free_space', objp ffff880023e7d320 [132409.503355] ------------[ cut here ]------------ [132409.504241] kernel BUG at mm/slab.c:2571! Therefore fix this by having btrfs_unpin_free_ino() acquire the lock that protects the rbtree while doing the searches and removing entries. Fixes: 1c70d8f ("Btrfs: fix inode caching vs tree log") Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>

Often when running fstests btrfs/079 I was running into the following trace during umount on one of my qemu/kvm test vms: [ 8245.682441] WARNING: CPU: 8 PID: 25064 at fs/btrfs/extent-tree.c:138 btrfs_put_block_group+0x51/0x69 [btrfs]() [ 8245.685039] Modules linked in: btrfs dm_flakey dm_mod crc32c_generic xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc loop fuse parport_pc i2c_piix4 acpi_cpufreq processor psmouse i2c_core thermal_sys parport evdev serio_raw button pcspkr microcode ext4 crc16 jbd2 mbcache sg sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata floppy virtio_pci virtio_ring scsi_mod virtio e1000 [last unloaded: btrfs] [ 8245.693860] CPU: 8 PID: 25064 Comm: umount Tainted: G W 4.1.0-rc5-btrfs-next-10+ #1 [ 8245.695081] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20150316_085822-nilsson.home.kraxel.org 04/01/2014 [ 8245.697583] 0000000000000009 ffff88020d047ce8 ffffffff8145eec7 ffffffff81095dce [ 8245.699234] 0000000000000000 ffff88020d047d28 ffffffff8104b399 0000000000000028 [ 8245.700995] ffffffffa04db07b ffff8801c6036c00 ffff8801c6036d68 ffff880202eb40b0 [ 8245.702510] Call Trace: [ 8245.703006] [<ffffffff8145eec7>] dump_stack+0x4f/0x7b [ 8245.705393] [<ffffffff81095dce>] ? console_unlock+0x356/0x3a2 [ 8245.706569] [<ffffffff8104b399>] warn_slowpath_common+0xa1/0xbb [ 8245.707747] [<ffffffffa04db07b>] ? btrfs_put_block_group+0x51/0x69 [btrfs] [ 8245.709101] [<ffffffff8104b456>] warn_slowpath_null+0x1a/0x1c [ 8245.710274] [<ffffffffa04db07b>] btrfs_put_block_group+0x51/0x69 [btrfs] [ 8245.711823] [<ffffffffa04e3473>] btrfs_free_block_groups+0x145/0x322 [btrfs] [ 8245.713251] [<ffffffffa04ef31a>] close_ctree+0x1ef/0x325 [btrfs] [ 8245.714448] [<ffffffff8117d26e>] ? evict_inodes+0xdc/0xeb [ 8245.715539] [<ffffffffa04cb3ad>] btrfs_put_super+0x19/0x1b [btrfs] [ 8245.716835] [<ffffffff81167607>] generic_shutdown_super+0x73/0xef [ 8245.718015] [<ffffffff81167a3a>] kill_anon_super+0x13/0x1e [ 8245.719101] [<ffffffffa04cb1b6>] btrfs_kill_super+0x17/0x23 [btrfs] [ 8245.720316] [<ffffffff81167544>] deactivate_locked_super+0x3b/0x68 [ 8245.721517] [<ffffffff81167dd6>] deactivate_super+0x3f/0x43 [ 8245.722581] [<ffffffff8117fbb9>] cleanup_mnt+0x59/0x78 [ 8245.723538] [<ffffffff8117fc18>] __cleanup_mnt+0x12/0x14 [ 8245.724572] [<ffffffff81065371>] task_work_run+0x8f/0xbc [ 8245.725598] [<ffffffff810028fb>] do_notify_resume+0x45/0x53 [ 8245.726892] [<ffffffff814651ac>] int_signal+0x12/0x17 [ 8245.737887] ---[ end trace a01d038397e99b92 ]--- [ 8245.769363] general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC [ 8245.770737] Modules linked in: btrfs dm_flakey dm_mod crc32c_generic xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc loop fuse parport_pc i2c_piix4 acpi_cpufreq processor psmouse i2c_core thermal_sys parport evdev serio_raw button pcspkr microcode ext4 crc16 jbd2 mbcache sg sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata floppy virtio_pci virtio_ring scsi_mod virtio e1000 [last unloaded: btrfs] [ 8245.772641] CPU: 2 PID: 25064 Comm: umount Tainted: G W 4.1.0-rc5-btrfs-next-10+ #1 [ 8245.772641] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20150316_085822-nilsson.home.kraxel.org 04/01/2014 [ 8245.772641] task: ffff880013005810 ti: ffff88020d044000 task.ti: ffff88020d044000 [ 8245.772641] RIP: 0010:[<ffffffffa051c8e6>] [<ffffffffa051c8e6>] btrfs_queue_work+0x2c/0x14d [btrfs] [ 8245.772641] RSP: 0018:ffff88020d0478b8 EFLAGS: 00010202 [ 8245.772641] RAX: 0000000000000004 RBX: 6b6b6b6b6b6b6b6b RCX: ffffffffa0581488 [ 8245.772641] RDX: 0000000000000000 RSI: ffff880194b7bf48 RDI: ffff880144b6a7a0 [ 8245.772641] RBP: ffff88020d0478d8 R08: 0000000000000000 R09: 000000000000ffff [ 8245.772641] R10: 0000000000000004 R11: 0000000000000005 R12: ffff880194b7bf48 [ 8245.772641] R13: ffff880194b7bf48 R14: 0000000000000410 R15: 0000000000000000 [ 8245.772641] FS: 00007f991e77d840(0000) GS:ffff88023e280000(0000) knlGS:0000000000000000 [ 8245.772641] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 8245.772641] CR2: 00007fbbd325ee68 CR3: 000000021de8e000 CR4: 00000000000006e0 [ 8245.772641] Stack: [ 8245.772641] ffff880194b7bf00 ffff880202eb4000 ffff880194b7bf48 0000000000000410 [ 8245.772641] ffff88020d047958 ffffffffa04ec6d5 ffff8801629b2ee8 0000000082987570 [ 8245.772641] 0000000000a5813f 0000000000000001 ffff880013006100 0000000000000002 [ 8245.772641] Call Trace: [ 8245.772641] [<ffffffffa04ec6d5>] btrfs_wq_submit_bio+0xe1/0x17b [btrfs] [ 8245.772641] [<ffffffff81086bff>] ? check_irq_usage+0x76/0x87 [ 8245.772641] [<ffffffffa04ec825>] btree_submit_bio_hook+0xb6/0xd9 [btrfs] [ 8245.772641] [<ffffffffa04ebb7c>] ? btree_csum_one_bio+0xad/0xad [btrfs] [ 8245.772641] [<ffffffffa04eb1a6>] ? btree_io_failed_hook+0x5e/0x5e [btrfs] [ 8245.772641] [<ffffffffa050a6e7>] submit_one_bio+0x8c/0xc7 [btrfs] [ 8245.772641] [<ffffffffa050d75b>] submit_extent_page.isra.18+0x9d/0x186 [btrfs] [ 8245.772641] [<ffffffffa050d95b>] write_one_eb+0x117/0x1ae [btrfs] [ 8245.772641] [<ffffffffa050a79b>] ? end_extent_buffer_writeback+0x21/0x21 [btrfs] [ 8245.772641] [<ffffffffa0510510>] btree_write_cache_pages+0x2ab/0x385 [btrfs] [ 8245.772641] [<ffffffffa04eb2b8>] btree_writepages+0x23/0x5c [btrfs] [ 8245.772641] [<ffffffff8111c661>] do_writepages+0x23/0x2c [ 8245.772641] [<ffffffff81189cd4>] __writeback_single_inode+0xda/0x5bd [ 8245.772641] [<ffffffff8118aa60>] ? writeback_single_inode+0x2b/0x173 [ 8245.772641] [<ffffffff8118aafd>] writeback_single_inode+0xc8/0x173 [ 8245.772641] [<ffffffff8118ac95>] write_inode_now+0x8a/0x95 [ 8245.772641] [<ffffffff81247bf0>] ? _atomic_dec_and_lock+0x30/0x4e [ 8245.772641] [<ffffffff8117cc5e>] iput+0x17d/0x26a [ 8245.772641] [<ffffffffa04ef355>] close_ctree+0x22a/0x325 [btrfs] [ 8245.772641] [<ffffffff8117d26e>] ? evict_inodes+0xdc/0xeb [ 8245.772641] [<ffffffffa04cb3ad>] btrfs_put_super+0x19/0x1b [btrfs] [ 8245.772641] [<ffffffff81167607>] generic_shutdown_super+0x73/0xef [ 8245.772641] [<ffffffff81167a3a>] kill_anon_super+0x13/0x1e [ 8245.772641] [<ffffffffa04cb1b6>] btrfs_kill_super+0x17/0x23 [btrfs] [ 8245.772641] [<ffffffff81167544>] deactivate_locked_super+0x3b/0x68 [ 8245.772641] [<ffffffff81167dd6>] deactivate_super+0x3f/0x43 [ 8245.772641] [<ffffffff8117fbb9>] cleanup_mnt+0x59/0x78 [ 8245.772641] [<ffffffff8117fc18>] __cleanup_mnt+0x12/0x14 [ 8245.772641] [<ffffffff81065371>] task_work_run+0x8f/0xbc [ 8245.772641] [<ffffffff810028fb>] do_notify_resume+0x45/0x53 [ 8245.772641] [<ffffffff814651ac>] int_signal+0x12/0x17 [ 8245.772641] Code: 1f 44 00 00 55 48 89 e5 41 56 41 55 41 54 53 49 89 f4 48 8b 46 70 a8 04 74 09 48 8b 5f 08 48 85 db 75 03 48 8b 1f 49 89 5c 24 68 <83> 7b 5c ff 74 04 f0 ff 43 50 49 83 7c 24 08 00 74 2c 4c 8d 6b [ 8245.772641] RIP [<ffffffffa051c8e6>] btrfs_queue_work+0x2c/0x14d [btrfs] [ 8245.772641] RSP <ffff88020d0478b8> [ 8245.845040] ---[ end trace a01d038397e99b93 ]--- For logical reasons such as the phase of the moon, this happened more often with "-o inode_cache" than without any mount options. After some debugging it turned out to be simple to understand what was happening: 1) close_ctree() is called; 2) It then stops the transaction kthread, which commits the current transaction; 3) It asks the cleaner kthread to stop, which is currently running btrfs_delete_unused_bgs(); 4) btrfs_delete_unused_bgs() finds an unused block group, starts a new transaction, deletes the block group, which implies COWing some tree nodes and leafs and dirtying their respective pages, and then finally it ends the transaction it started, without committing it; 5) The cleaner kthread stops; 6) close_ctree() releases (from memory) the block group objects, which produces the warning in the trace pasted above; 7) Then it invalidates all pages of the btree inode, by calling invalidate_inode_pages2(), which waits for any pages under writeback, and releases any non-dirty pages; 8) All work queues are destroyed (waiting first for their current tasks to finish execution); 9) A final iput() is called against the btree inode; 10) This iput triggers a writeback of the btree inode because it still has dirty pages; 11) This starts the whole chain of callbacks for the btree inode until it eventually reaches btrfs_wq_submit_bio() where it leads to a NULL pointer dereference because the work queues were already destroyed. Fix this by making the cleaner commit any transaction that it started after the transaction kthread was stopped. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>

Jean reported another crash, similar to the one fixed by feaff8e: BUG: unable to handle kernel NULL pointer dereference at 0000000000000148 IP: [<ffffffff8124ef7f>] locks_get_lock_context+0xf/0xa0 PGD 0 Oops: 0000 [#1] SMP Modules linked in: nfsv3 nfs_layout_flexfiles rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache vmw_vsock_vmci_transport vsock cfg80211 rfkill coretemp crct10dif_pclmul ppdev vmw_balloon crc32_pclmul crc32c_intel ghash_clmulni_intel pcspkr vmxnet3 parport_pc i2c_piix4 microcode serio_raw parport nfsd floppy vmw_vmci acpi_cpufreq auth_rpcgss shpchp nfs_acl lockd grace sunrpc vmwgfx drm_kms_helper ttm drm mptspi scsi_transport_spi mptscsih ata_generic mptbase i2c_core pata_acpi CPU: 0 PID: 329 Comm: kworker/0:1H Not tainted 4.1.0-rc7+ #2 Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/30/2013 Workqueue: rpciod rpc_async_schedule [sunrpc] 30ec000 RIP: 0010:[<ffffffff8124ef7f>] [<ffffffff8124ef7f>] locks_get_lock_context+0xf/0xa0 RSP: 0018:ffff8802330efc08 EFLAGS: 00010296 RAX: ffff8802330efc58 RBX: ffff880097187c80 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000 RBP: ffff8802330efc18 R08: ffff88023fc173d8 R09: 3038b7bf00000000 R10: 00002f1a02000000 R11: 3038b7bf00000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffff8802337a2300 R15: 0000000000000020 FS: 0000000000000000(0000) GS:ffff88023fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000148 CR3: 000000003680f000 CR4: 00000000001407f0 Stack: ffff880097187c80 ffff880097187cd8 ffff8802330efc98 ffffffff81250281 ffff8802330efc68 ffffffffa013e7df ffff8802330efc98 0000000000000246 ffff8801f6901c00 ffff880233d2b8d8 ffff8802330efc58 ffff8802330efc58 Call Trace: [<ffffffff81250281>] __posix_lock_file+0x31/0x5e0 [<ffffffffa013e7df>] ? rpc_wake_up_task_queue_locked.part.35+0xcf/0x240 [sunrpc] [<ffffffff8125088b>] posix_lock_file_wait+0x3b/0xd0 [<ffffffffa03890b2>] ? nfs41_wake_and_assign_slot+0x32/0x40 [nfsv4] [<ffffffffa0365808>] ? nfs41_sequence_done+0xd8/0x300 [nfsv4] [<ffffffffa0367525>] do_vfs_lock+0x35/0x40 [nfsv4] [<ffffffffa03690c1>] nfs4_locku_done+0x81/0x120 [nfsv4] [<ffffffffa013e310>] ? rpc_destroy_wait_queue+0x20/0x20 [sunrpc] [<ffffffffa013e310>] ? rpc_destroy_wait_queue+0x20/0x20 [sunrpc] [<ffffffffa013e33c>] rpc_exit_task+0x2c/0x90 [sunrpc] [<ffffffffa0134400>] ? call_refreshresult+0x170/0x170 [sunrpc] [<ffffffffa013ece4>] __rpc_execute+0x84/0x410 [sunrpc] [<ffffffffa013f085>] rpc_async_schedule+0x15/0x20 [sunrpc] [<ffffffff810add67>] process_one_work+0x147/0x400 [<ffffffff810ae42b>] worker_thread+0x11b/0x460 [<ffffffff810ae310>] ? rescuer_thread+0x2f0/0x2f0 [<ffffffff810b35d9>] kthread+0xc9/0xe0 [<ffffffff81010000>] ? perf_trace_xen_mmu_set_pmd+0xa0/0x160 [<ffffffff810b3510>] ? kthread_create_on_node+0x170/0x170 [<ffffffff8173c222>] ret_from_fork+0x42/0x70 [<ffffffff810b3510>] ? kthread_create_on_node+0x170/0x170 Code: a5 81 e8 85 75 e4 ff c6 05 31 ee aa 00 01 eb 98 66 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 54 49 89 fc 53 <48> 8b 9f 48 01 00 00 48 85 db 74 08 48 89 d8 5b 41 5c 5d c3 83 RIP [<ffffffff8124ef7f>] locks_get_lock_context+0xf/0xa0 RSP <ffff8802330efc08> CR2: 0000000000000148 ---[ end trace 64484f16250de7ef ]--- The problem is almost exactly the same as the one fixed by feaff8e. We must take a reference to the struct file when running the LOCKU compound to prevent the final fput from running until the operation is complete. Reported-by: Jean Spector <jean@primarydata.com> Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> Cc: stable@vger.kernel.org Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

If we fail to submit a bio for a direct IO request, we were grabbing the corresponding ordered extent and decrementing its reference count twice, once for our lookup reference and once for the ordered tree reference. This was a problem because it caused the ordered extent to be freed without removing it from the ordered tree and any lists it might be attached to, leaving dangling pointers to the ordered extent around. Example trace with CONFIG_DEBUG_PAGEALLOC=y: [161779.858707] BUG: unable to handle kernel paging request at 0000000087654330 [161779.859983] IP: [<ffffffff8124ca68>] rb_prev+0x22/0x3b [161779.860636] PGD 34d818067 PUD 0 [161779.860636] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC (...) [161779.860636] Call Trace: [161779.860636] [<ffffffffa06b36a6>] __tree_search+0xd9/0xf9 [btrfs] [161779.860636] [<ffffffffa06b3708>] tree_search+0x42/0x63 [btrfs] [161779.860636] [<ffffffffa06b4868>] ? btrfs_lookup_ordered_range+0x2d/0xa5 [btrfs] [161779.860636] [<ffffffffa06b4873>] btrfs_lookup_ordered_range+0x38/0xa5 [btrfs] [161779.860636] [<ffffffffa06aab8e>] btrfs_get_blocks_direct+0x11b/0x615 [btrfs] [161779.860636] [<ffffffff8119727f>] do_blockdev_direct_IO+0x5ff/0xb43 [161779.860636] [<ffffffffa06aaa73>] ? btrfs_page_exists_in_range+0x1ad/0x1ad [btrfs] [161779.860636] [<ffffffffa06a2c9a>] ? btrfs_get_extent_fiemap+0x1bc/0x1bc [btrfs] [161779.860636] [<ffffffff811977f5>] __blockdev_direct_IO+0x32/0x34 [161779.860636] [<ffffffffa06a2c9a>] ? btrfs_get_extent_fiemap+0x1bc/0x1bc [btrfs] [161779.860636] [<ffffffffa06a10ae>] btrfs_direct_IO+0x198/0x21f [btrfs] [161779.860636] [<ffffffffa06a2c9a>] ? btrfs_get_extent_fiemap+0x1bc/0x1bc [btrfs] [161779.860636] [<ffffffff81112ca1>] generic_file_direct_write+0xb3/0x128 [161779.860636] [<ffffffffa06affaa>] ? btrfs_file_write_iter+0x15f/0x3e0 [btrfs] [161779.860636] [<ffffffffa06b004c>] btrfs_file_write_iter+0x201/0x3e0 [btrfs] (...) We were also not freeing the btrfs_dio_private we allocated previously, which kmemleak reported with the following trace in its sysfs file: unreferenced object 0xffff8803f553bf80 (size 96): comm "xfs_io", pid 4501, jiffies 4295039588 (age 173.936s) hex dump (first 32 bytes): 88 6c 9b f5 02 88 ff ff 00 00 00 00 00 00 00 00 .l.............. 00 00 00 00 00 00 00 00 00 00 c4 00 00 00 00 00 ................ backtrace: [<ffffffff81161ffe>] create_object+0x172/0x29a [<ffffffff8145870f>] kmemleak_alloc+0x25/0x41 [<ffffffff81154e64>] kmemleak_alloc_recursive.constprop.40+0x16/0x18 [<ffffffff811579ed>] kmem_cache_alloc_trace+0xfb/0x148 [<ffffffffa03d8cff>] btrfs_submit_direct+0x65/0x16a [btrfs] [<ffffffff811968dc>] dio_bio_submit+0x62/0x8f [<ffffffff811975fe>] do_blockdev_direct_IO+0x97e/0xb43 [<ffffffff811977f5>] __blockdev_direct_IO+0x32/0x34 [<ffffffffa03d70ae>] btrfs_direct_IO+0x198/0x21f [btrfs] [<ffffffff81112ca1>] generic_file_direct_write+0xb3/0x128 [<ffffffffa03e604d>] btrfs_file_write_iter+0x201/0x3e0 [btrfs] [<ffffffff8116586a>] __vfs_write+0x7c/0xa5 [<ffffffff81165da9>] vfs_write+0xa0/0xe4 [<ffffffff81166675>] SyS_pwrite64+0x64/0x82 [<ffffffff81464fd7>] system_call_fastpath+0x12/0x6f [<ffffffffffffffff>] 0xffffffffffffffff For read requests we weren't doing any cleanup either (none of the work done by btrfs_endio_direct_read()), so a failure submitting a bio for a read request would leave a range in the inode's io_tree locked forever, blocking any future operations (both reads and writes) against that range. So fix this by making sure we do the same cleanup that we do for the case where the bio submission succeeds. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>

Jan Kara and Thomas Gleixner reported boot crashes in the FPU code: general protection fault: 0000 [#1] SMP RIP: 0010:[<ffffffff81048a6c>] [<ffffffff81048a6c>] mxcsr_feature_mask_init+0x1c/0x40 2b:* 0f ae 85 00 fe ff ff fxsave -0x200(%rbp) and bisected it down to the following FPU commit: 91a8c2a ("x86/fpu: Clean up and fix MXCSR handling") The reason is that the on-stack FPU registers state variable, used by the FXSAVE instruction, did not have the required minimum alignment of 16 bytes, causing the general protection fault. This is most likely a GCC bug in older GCC versions, but the offending commit also added a bogus extra 32-byte alignment (which GCC ignored too). So fix this bug by making the variable static again, but also mark it __initdata this time, because fpu__init_system_mxcsr() is now an __init function. Reported-and-bisected-by: Jan Kara <jack@suse.cz> Reported-bisected-and-tested-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jan Kara <jack@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20150704075819.GA9201@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>

…nterface When cpsw's number of slave is set to 1 in device tree and while accessing second slave ndev and priv in cpsw_tx_interrupt(), there is a kernel crash. This is due to cpsw_get_slave_priv() not verifying number of slaves while retriving netdev priv and returns a invalid memory region. Fixing the issue by introducing number of slave check in cpsw_get_slave_priv() and cpsw_get_slave_ndev(). [ 15.879589] Unable to handle kernel paging request at virtual address 0f0e142c [ 15.888540] pgd = ed374000 [ 15.891359] [0f0e142c] *pgd=00000000 [ 15.895105] Internal error: Oops: 5 [#1] SMP ARM [ 15.899936] Modules linked in: [ 15.903139] CPU: 0 PID: 593 Comm: udhcpc Tainted: G W 4.1.0-12205-gfda8b18-dirty torvalds#10 [ 15.912386] Hardware name: Generic AM43 (Flattened Device Tree) [ 15.918557] task: ed2a2e00 ti: ed3fe000 task.ti: ed3fe000 [ 15.924187] PC is at cpsw_tx_interrupt+0x30/0x44 [ 15.929008] LR is at _raw_spin_unlock_irqrestore+0x40/0x44 [ 15.934726] pc : [<c048b9cc>] lr : [<c05ef4f4>] psr: 20000193 [ 15.934726] sp : ed3ffc08 ip : ed2a2e40 fp : 00000000 [ 15.946685] r10: c0969ce8 r9 : c0969cfc r8 : 00000000 [ 15.952129] r7 : 000000c6 r6 : ee54ab00 r5 : ee169c64 r4 : ee534e00 [ 15.958932] r3 : 0f0e0d0c r2 : 00000000 r1 : ed3ffbc0 r0 : 00000001 [ 15.965735] Flags: nzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment user [ 15.973261] Control: 10c5387d Table: ad374059 DAC: 00000015 [ 15.979246] Process udhcpc (pid: 593, stack limit = 0xed3fe218) [ 15.985414] Stack: (0xed3ffc08 to 0xed400000) [ 15.989954] fc00: ee54ab00 c009928c c0a9e648 60000193 000032e4 ee169c00 [ 15.998478] fc20: ee169c64 ee169c00 ee169c64 ee54ab00 00000001 00000001 ee67e268 ee008800 [ 16.006995] fc40: ee534800 c009946c ee169c00 ee169c64 c08bd660 c009c370 c009c2a4 000000c6 [ 16.015513] fc60: c08b75c4 c08b0854 00000000 c0098b3c 000000c6 c0098c50 ed3ffcb0 0000003a [ 16.024033] fc80: ed3ffcb0 fa24010c c08b7800 fa240100 ee7e9880 c00094c4 c05ef4e8 60000013 [ 16.032556] fca0: ffffffff ed3ffce4 ee7e9880 c05ef964 00000001 ed2a33d8 00000000 ed2a2e00 [ 16.041080] fcc0: 60000013 ee536bf8 60000013 ee51b800 ee7e9880 ee67e268 ee7e9880 ee534800 [ 16.049603] fce0: c0ad0768 ed3ffcf8 c008e910 c05ef4e8 60000013 ffffffff 00000001 00000001 [ 16.058121] fd00: ee536bf8 c0487a04 00000000 00000000 ee534800 00000000 00000156 c048c990 [ 16.066645] fd20: 00000000 00000000 c0969f40 00000000 00000000 c05000e8 00000001 00000000 [ 16.075167] fd40: 00000000 c051eefc 00000000 ee67e268 00000000 00000000 ee51b800 ed3ffd9c [ 16.083690] fd60: 00000000 ee67e200 ee51b800 ee7e9880 ee67e268 00000000 00000000 ee67e200 [ 16.092211] fd80: ee51b800 ee7e9880 ee67e268 ee534800 ee67e200 c051eedc ee67e268 00000010 [ 16.100727] fda0: 00000000 00000000 ee7e9880 ee534800 00000000 ee67e268 ee51b800 c05006fc [ 16.109247] fdc0: ee67e268 00000001 c0500488 00000156 ee7e9880 00000000 ed3fe000 fffffff4 [ 16.117771] fde0: ed3fff1c ee7e9880 ee534800 00000148 00000000 ed1f8340 00000000 00000000 [ 16.126289] fe00: 00000000 c05a9054 00000000 00000000 00000156 c0ab62a8 00000010 ed3e7000 [ 16.134812] fe20: 00000000 00000008 edcfb700 ed3fff1c c0fb5f94 ed2a2e00 c0fb5f64 000005d8 [ 16.143336] fe40: c0a9b3b8 00000000 ed3e7070 00000000 00000000 00000000 00009f40 00000000 [ 16.151858] fe60: 00000000 00020022 00110008 00000000 00000000 43004400 00000000 ffffffff [ 16.160374] fe80: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [ 16.168898] fea0: edcfb700 bee5f380 00000014 00000000 ed3fe000 00000000 00004400 c04e2b64 [ 16.177415] fec0: 00000002 c04e3b00 ed3ffeec 00000001 0000011a 00000000 00000000 bee5f394 [ 16.185937] fee0: 00000148 ed3fff10 00000014 00000001 00000000 00000000 ed3ffee4 00000000 [ 16.194459] ff00: 00000000 00000000 00000000 c04e3664 00080011 00000002 06000000 ffffffff [ 16.202980] ff20: 0000ffff ffffffff 0000ffff c008dd54 ee5a6f08 ee636e8 c096972d c0089c14 [ 16.211499] ff40: 00000000 60000013 ee5a6f40 60000013 00000000 ee5a6f40 00000002 00000006 [ 16.220023] ff60: 00000000 edcfb700 00000001 ed2a2e00 c000f60c 00000001 0000011a c008ea34 [ 16.228540] ff80: 00000006 00000000 bee5f380 00000014 bee5f380 00000014 bee5f380 00000122 [ 16.237059] ffa0: c000f7c4 c000f5e0 bee5f380 00000014 00000006 bee5f394 00000148 00000000 [ 16.245581] ffc0: bee5f380 00000014 bee5f380 00000122 fffffd6e 00004300 00004800 00004400 [ 16.254104] ffe0: bee5f378 bee5f36c 000307ec b6f39044 40000010 00000006 ed36fa40 00000000 [ 16.262642] [<c048b9cc>] (cpsw_tx_interrupt) from [<c009928c>] (handle_irq_event_percpu+0x64/0x204) [ 16.272076] [<c009928c>] (handle_irq_event_percpu) from [<c009946c>] (handle_irq_event+0x40/0x64) [ 16.281330] [<c009946c>] (handle_irq_event) from [<c009c370>] (handle_fasteoi_irq+0xcc/0x1a8) [ 16.290220] [<c009c370>] (handle_fasteoi_irq) from [<c0098b3c>] (generic_handle_irq+0x20/0x30) [ 16.299197] [<c0098b3c>] (generic_handle_irq) from [<c0098c50>] (__handle_domain_irq+0x64/0xdc) [ 16.308273] [<c0098c50>] (__handle_domain_irq) from [<c00094c4>] (gic_handle_irq+0x20/0x60) [ 16.316987] [<c00094c4>] (gic_handle_irq) from [<c05ef964>] (__irq_svc+0x44/0x5c) [ 16.324779] Exception stack(0xed3ffcb0 to 0xed3ffcf8) [ 16.330044] fca0: 00000001 ed2a33d8 00000000 ed2a2e00 [ 16.338567] fcc0: 60000013 ee536bf8 60000013 ee51b800 ee7e9880 ee67e268 ee7e9880 ee534800 [ 16.347090] fce0: c0ad0768 ed3ffcf8 c008e910 c05ef4e8 60000013 ffffffff [ 16.353987] [<c05ef964>] (__irq_svc) from [<c05ef4e8>] (_raw_spin_unlock_irqrestore+0x34/0x44) [ 16.362973] [<c05ef4e8>] (_raw_spin_unlock_irqrestore) from [<c0487a04>] (cpdma_check_free_tx_desc+0x60/0x6c) [ 16.373311] [<c0487a04>] (cpdma_check_free_tx_desc) from [<c048c990>] (cpsw_ndo_start_xmit+0xb4/0x1ac) [ 16.383017] [<c048c990>] (cpsw_ndo_start_xmit) from [<c05000e8>] (dev_hard_start_xmit+0x2a4/0x4c0) [ 16.392364] [<c05000e8>] (dev_hard_start_xmit) from [<c051eedc>] (sch_direct_xmit+0xf4/0x210) [ 16.401246] [<c051eedc>] (sch_direct_xmit) from [<c05006fc>] (__dev_queue_xmit+0x2ac/0x7bc) [ 16.409960] [<c05006fc>] (__dev_queue_xmit) from [<c05a9054>] (packet_sendmsg+0xc68/0xeb4) [ 16.418585] [<c05a9054>] (packet_sendmsg) from [<c04e2b64>] (sock_sendmsg+0x14/0x24) [ 16.426663] [<c04e2b64>] (sock_sendmsg) from [<c04e3b00>] (SyS_sendto+0xb4/0xe0) [ 16.434377] [<c04e3b00>] (SyS_sendto) from [<c000f5e0>] (ret_fast_syscall+0x0/0x54) [ 16.442360] Code: e5943118 e593303c e3530000 0a000002 (e5930720) [ 16.448716] ---[ end trace a68159f094d85ba6 ]--- [ 16.453526] Kernel panic - not syncing: Fatal exception in interrupt [ 16.460149] ---[ end Kernel panic - not syncing: Fatal exception in interrupt Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com> Cc: <stable@vger.kernel.org> # v3.8+ Signed-off-by: David S. Miller <davem@davemloft.net>

…ge based on timing results The increased use of pdtlb/pitlb instructions seemed to increase the frequency of random segmentation faults building packages. Further, we had a number of cases where TLB inserts would repeatedly fail and all forward progress would stop. The Haskell ghc package caused a lot of trouble in this area. The final indication of a race in pte handling was this syslog entry on sibaris (C8000): swap_free: Unused swap offset entry 00000004 BUG: Bad page map in process mysqld pte:00000100 pmd:019bbec5 addr:00000000ec464000 vm_flags:00100073 anon_vma:0000000221023828 mapping: (null) index:ec464 CPU: 1 PID: 9176 Comm: mysqld Not tainted 4.0.0-2-parisc64-smp #1 Debian 4.0.5-1 Backtrace: [<0000000040173eb0>] show_stack+0x20/0x38 [<0000000040444424>] dump_stack+0x9c/0x110 [<00000000402a0d38>] print_bad_pte+0x1a8/0x278 [<00000000402a28b8>] unmap_single_vma+0x3d8/0x770 [<00000000402a4090>] zap_page_range+0xf0/0x198 [<00000000402ba2a4>] SyS_madvise+0x404/0x8c0 Note that the pte value is 0 except for the accessed bit 0x100. This bit shouldn't be set without the present bit. It should be noted that the madvise system call is probably a trigger for many of the random segmentation faults. In looking at the kernel code, I found the following problems: 1) The pte_clear define didn't take TLB lock when clearing a pte. 2) We didn't test pte present bit inside lock in exception support. 3) The pte and tlb locks needed to merged in order to ensure consistency between page table and TLB. This also has the effect of serializing TLB broadcasts on SMP systems. The attached change implements the above and a few other tweaks to try to improve performance. Based on the timing code, TLB purges are very slow (e.g., ~ 209 cycles per page on rp3440). Thus, I think it beneficial to test the split_tlb variable to avoid duplicate purges. Probably, all PA 2.0 machines have combined TLBs. I dropped using __flush_tlb_range in flush_tlb_mm as I realized all applications and most threads have a stack size that is too large to make this useful. I added some comments to this effect. Since implementing 1 through 3, I haven't had any random segmentation faults on mx3210 (rp3440) in about one week of building code and running as a Debian buildd. Signed-off-by: John David Anglin <dave.anglin@bell.net> Cc: stable@vger.kernel.org # v3.18+ Signed-off-by: Helge Deller <deller@gmx.de>

__ipoib_ib_dev_flush calls itself recursively on child devices, and lockdep complains about locking vlan_rwsem twice (see below). Use down_read_nested instead of down_read to prevent the warning. ============================================= [ INFO: possible recursive locking detected ] 4.1.0-rc4+ torvalds#36 Tainted: G O --------------------------------------------- kworker/u20:2/261 is trying to acquire lock: (&priv->vlan_rwsem){.+.+..}, at: [<ffffffffa0791e2a>] __ipoib_ib_dev_flush+0x3a/0x2b0 [ib_ipoib] but task is already holding lock: (&priv->vlan_rwsem){.+.+..}, at: [<ffffffffa0791e2a>] __ipoib_ib_dev_flush+0x3a/0x2b0 [ib_ipoib] other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&priv->vlan_rwsem); lock(&priv->vlan_rwsem); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by kworker/u20:2/261: #0: ("%s""ipoib_flush"){.+.+..}, at: [<ffffffff810827cc>] process_one_work+0x15c/0x760 #1: ((&priv->flush_heavy)){+.+...}, at: [<ffffffff810827cc>] process_one_work+0x15c/0x760 #2: (&priv->vlan_rwsem){.+.+..}, at: [<ffffffffa0791e2a>] __ipoib_ib_dev_flush+0x3a/0x2b0 [ib_ipoib] stack backtrace: CPU: 3 PID: 261 Comm: kworker/u20:2 Tainted: G O 4.1.0-rc4+ torvalds#36 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2007 Workqueue: ipoib_flush ipoib_ib_dev_flush_heavy [ib_ipoib] ffff8801c6c54790 ffff8801c9927af8 ffffffff81665238 0000000000000001 ffffffff825b5b30 ffff8801c9927bd8 ffffffff810bba51 ffff880100000000 ffffffff00000001 ffff880100000001 ffff8801c6c55428 ffff8801c6c54790 Call Trace: [<ffffffff81665238>] dump_stack+0x4f/0x6f [<ffffffff810bba51>] __lock_acquire+0x741/0x1820 [<ffffffff810bcbf8>] lock_acquire+0xc8/0x240 [<ffffffffa0791e2a>] ? __ipoib_ib_dev_flush+0x3a/0x2b0 [ib_ipoib] [<ffffffff81669d2c>] down_read+0x4c/0x70 [<ffffffffa0791e2a>] ? __ipoib_ib_dev_flush+0x3a/0x2b0 [ib_ipoib] [<ffffffffa0791e2a>] __ipoib_ib_dev_flush+0x3a/0x2b0 [ib_ipoib] [<ffffffffa0791e4a>] __ipoib_ib_dev_flush+0x5a/0x2b0 [ib_ipoib] [<ffffffffa07920ba>] ipoib_ib_dev_flush_heavy+0x1a/0x20 [ib_ipoib] [<ffffffff81082871>] process_one_work+0x201/0x760 [<ffffffff810827cc>] ? process_one_work+0x15c/0x760 [<ffffffff81082ef0>] worker_thread+0x120/0x4d0 [<ffffffff81082dd0>] ? process_one_work+0x760/0x760 [<ffffffff81082dd0>] ? process_one_work+0x760/0x760 [<ffffffff81088b7e>] kthread+0xfe/0x120 [<ffffffff81088a80>] ? __init_kthread_worker+0x70/0x70 [<ffffffff8166c6e2>] ret_from_fork+0x42/0x70 [<ffffffff81088a80>] ? __init_kthread_worker+0x70/0x70 Signed-off-by: Haggai Eran <haggaie@mellanox.com> Signed-off-by: Doug Ledford <dledford@redhat.com>

[ 1572.417121] BUG: unable to handle kernel NULL pointer dereference at (null) [ 1572.421010] IP: [<ffffffffa00b2514>] ftrace_raw_event_i915_context+0x5d/0x70 [i915] [ 1572.424970] PGD 1766a3067 PUD 1767a2067 PMD 0 [ 1572.428892] Oops: 0000 [#1] SMP [ 1572.432787] Modules linked in: ipv6 dm_mod iTCO_wdt iTCO_vendor_support snd_hda_codec_realtek snd_hda_codec_generic snd_hda_intel snd_hda_controller snd_hda_codec snd_hda_core snd_hwdep snd_pcm snd_timer snd soundcore serio_raw pcspkr lpc_ich i2c_i801 mfd_core battery ac acpi_cpufreq i915 button video drm_kms_helper drm [ 1572.441720] CPU: 2 PID: 18853 Comm: kworker/u8:0 Not tainted 4.0.0_kcloud_3f0360_20150429+ torvalds#588 [ 1572.446298] Workqueue: i915 i915_gem_retire_work_handler [i915] [ 1572.450876] task: ffff880002f428f0 ti: ffff880035724000 task.ti: ffff880035724000 [ 1572.455557] RIP: 0010:[<ffffffffa00b2514>] [<ffffffffa00b2514>] ftrace_raw_event_i915_context+0x5d/0x70 [i915] [ 1572.460423] RSP: 0018:ffff880035727ce8 EFLAGS: 00010286 [ 1572.465262] RAX: ffff880073f1643c RBX: ffff880002da9058 RCX: ffff880073e5db40 [ 1572.470179] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff880035727ce8 [ 1572.475107] RBP: ffff88007bb11a00 R08: 0000000000000000 R09: 0000000000000000 [ 1572.480034] R10: 0000000000362200 R11: 0000000000000008 R12: 0000000000000000 [ 1572.484952] R13: ffff880035727d78 R14: ffff880002dc1c98 R15: ffff880002dc1dc8 [ 1572.489886] FS: 0000000000000000(0000) GS:ffff88017fd00000(0000) knlGS:0000000000000000 [ 1572.494883] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 1572.499859] CR2: 0000000000000000 CR3: 000000017572a000 CR4: 00000000001006e0 [ 1572.504842] Stack: [ 1572.509834] ffff88017b0090c0 ffff880073f16438 ffff880002da9058 ffff880073f1643c [ 1572.514904] 0000000000000246 ffff880100000000 ffff88007bb11a00 ffff880002ddeb10 [ 1572.519985] ffff8801759f79c0 ffffffffa0092ff0 0000000000000000 ffff88007bb11a00 [ 1572.525049] Call Trace: [ 1572.530093] [<ffffffffa0092ff0>] ? i915_gem_context_free+0xa8/0xc1 [i915] [ 1572.535227] [<ffffffffa009b969>] ? i915_gem_request_free+0x4e/0x50 [i915] [ 1572.540347] [<ffffffffa00b5533>] ? intel_execlists_retire_requests+0x14c/0x159 [i915] [ 1572.545500] [<ffffffffa009d9ea>] ? i915_gem_retire_requests+0x9d/0xeb [i915] [ 1572.550664] [<ffffffffa009dd8c>] ? i915_gem_retire_work_handler+0x4c/0x61 [i915] [ 1572.555825] [<ffffffff8104ca7f>] ? process_one_work+0x1b2/0x31d [ 1572.560951] [<ffffffff8104d278>] ? worker_thread+0x24d/0x339 [ 1572.566033] [<ffffffff8104d02b>] ? cancel_delayed_work_sync+0xa/0xa [ 1572.571140] [<ffffffff81050b25>] ? kthread+0xce/0xd6 [ 1572.576191] [<ffffffff81050a57>] ? kthread_create_on_node+0x162/0x162 [ 1572.581228] [<ffffffff8179b3c8>] ? ret_from_fork+0x58/0x90 [ 1572.586259] [<ffffffff81050a57>] ? kthread_create_on_node+0x162/0x162 [ 1572.591318] Code: de 48 89 e7 e8 09 4d 00 e1 48 85 c0 74 27 48 89 68 10 48 8b 55 38 48 89 e7 48 89 50 18 48 8b 55 10 48 8b 12 48 8b 12 48 8b 52 38 <8b> 12 89 50 08 e8 95 4d 00 e1 48 83 c4 30 5b 5d 41 5c c3 41 55 [ 1572.596981] RIP [<ffffffffa00b2514>] ftrace_raw_event_i915_context+0x5d/0x70 [i915] [ 1572.602464] RSP <ffff880035727ce8> [ 1572.607911] CR2: 0000000000000000 Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=90112#c23 Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Using the clone ioctl (or extent_same ioctl, which calls the same extent cloning function as well) we end up allowing copy an inline extent from the source file into a non-zero offset of the destination file. This is something not expected and that the btrfs code is not prepared to deal with - all inline extents must be at a file offset equals to 0. For example, the following excerpt of a test case for fstests triggers a crash/BUG_ON() on a write operation after an inline extent is cloned into a non-zero offset: _scratch_mkfs >>$seqres.full 2>&1 _scratch_mount # Create our test files. File foo has the same 2K of data at offset 4K # as file bar has at its offset 0. $XFS_IO_PROG -f -s -c "pwrite -S 0xaa 0 4K" \ -c "pwrite -S 0xbb 4k 2K" \ -c "pwrite -S 0xcc 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # File bar consists of a single inline extent (2K size). $XFS_IO_PROG -f -s -c "pwrite -S 0xbb 0 2K" \ $SCRATCH_MNT/bar | _filter_xfs_io # Now call the clone ioctl to clone the extent of file bar into file # foo at its offset 4K. This made file foo have an inline extent at # offset 4K, something which the btrfs code can not deal with in future # IO operations because all inline extents are supposed to start at an # offset of 0, resulting in all sorts of chaos. # So here we validate that clone ioctl returns an EOPNOTSUPP, which is # what it returns for other cases dealing with inlined extents. $CLONER_PROG -s 0 -d $((4 * 1024)) -l $((2 * 1024)) \ $SCRATCH_MNT/bar $SCRATCH_MNT/foo # Because of the inline extent at offset 4K, the following write made # the kernel crash with a BUG_ON(). $XFS_IO_PROG -c "pwrite -S 0xdd 6K 2K" $SCRATCH_MNT/foo | _filter_xfs_io status=0 exit The stack trace of the BUG_ON() triggered by the last write is: [152154.035903] ------------[ cut here ]------------ [152154.036424] kernel BUG at mm/page-writeback.c:2286! [152154.036424] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC [152154.036424] Modules linked in: btrfs dm_flakey dm_mod crc32c_generic xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc loop fuse parport_pc acpi_cpu$ [152154.036424] CPU: 2 PID: 17873 Comm: xfs_io Tainted: G W 4.1.0-rc6-btrfs-next-11+ #2 [152154.036424] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20150316_085822-nilsson.home.kraxel.org 04/01/2014 [152154.036424] task: ffff880429f70990 ti: ffff880429efc000 task.ti: ffff880429efc000 [152154.036424] RIP: 0010:[<ffffffff8111a9d5>] [<ffffffff8111a9d5>] clear_page_dirty_for_io+0x1e/0x90 [152154.036424] RSP: 0018:ffff880429effc68 EFLAGS: 00010246 [152154.036424] RAX: 0200000000000806 RBX: ffffea0006a6d8f0 RCX: 0000000000000001 [152154.036424] RDX: 0000000000000000 RSI: ffffffff81155d1b RDI: ffffea0006a6d8f0 [152154.036424] RBP: ffff880429effc78 R08: ffff8801ce389fe0 R09: 0000000000000001 [152154.036424] R10: 0000000000002000 R11: ffffffffffffffff R12: ffff8800200dce68 [152154.036424] R13: 0000000000000000 R14: ffff8800200dcc88 R15: ffff8803d5736d80 [152154.036424] FS: 00007fbf119f6700(0000) GS:ffff88043d280000(0000) knlGS:0000000000000000 [152154.036424] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [152154.036424] CR2: 0000000001bdc000 CR3: 00000003aa555000 CR4: 00000000000006e0 [152154.036424] Stack: [152154.036424] ffff8803d5736d80 0000000000000001 ffff880429effcd8 ffffffffa04e97c1 [152154.036424] ffff880429effd68 ffff880429effd60 0000000000000001 ffff8800200dc9c8 [152154.036424] 0000000000000001 ffff8800200dcc88 0000000000000000 0000000000001000 [152154.036424] Call Trace: [152154.036424] [<ffffffffa04e97c1>] lock_and_cleanup_extent_if_need+0x147/0x18d [btrfs] [152154.036424] [<ffffffffa04ea82c>] __btrfs_buffered_write+0x245/0x4c8 [btrfs] [152154.036424] [<ffffffffa04ed14b>] ? btrfs_file_write_iter+0x150/0x3e0 [btrfs] [152154.036424] [<ffffffffa04ed15a>] ? btrfs_file_write_iter+0x15f/0x3e0 [btrfs] [152154.036424] [<ffffffffa04ed2c7>] btrfs_file_write_iter+0x2cc/0x3e0 [btrfs] [152154.036424] [<ffffffff81165a4a>] __vfs_write+0x7c/0xa5 [152154.036424] [<ffffffff81165f89>] vfs_write+0xa0/0xe4 [152154.036424] [<ffffffff81166855>] SyS_pwrite64+0x64/0x82 [152154.036424] [<ffffffff81465197>] system_call_fastpath+0x12/0x6f [152154.036424] Code: 48 89 c7 e8 0f ff ff ff 5b 41 5c 5d c3 0f 1f 44 00 00 55 48 89 e5 41 54 53 48 89 fb e8 ae ef 00 00 49 89 c4 48 8b 03 a8 01 75 02 <0f> 0b 4d 85 e4 74 59 49 8b 3c 2$ [152154.036424] RIP [<ffffffff8111a9d5>] clear_page_dirty_for_io+0x1e/0x90 [152154.036424] RSP <ffff880429effc68> [152154.242621] ---[ end trace e3d3376b23a57041 ]--- Fix this by returning the error EOPNOTSUPP if an attempt to copy an inline extent into a non-zero offset happens, just like what is done for other scenarios that would require copying/splitting inline extents, which were introduced by the following commits: 00fdf13 ("Btrfs: fix a crash of clone with inline extents's split") 3f9e3df ("btrfs: replace error code from btrfs_drop_extents") Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com>

…_open Two SLES11 SP3 servers encountered similar crashes simultaneously following some kind of SAN/tape target issue: ... qla2xxx [0000:81:00.0]-801c:3: Abort command issued nexus=3:0:2 -- 1 2002. qla2xxx [0000:81:00.0]-801c:3: Abort command issued nexus=3:0:2 -- 1 2002. qla2xxx [0000:81:00.0]-8009:3: DEVICE RESET ISSUED nexus=3:0:2 cmd=ffff882f89c2c7c0. qla2xxx [0000:81:00.0]-800c:3: do_reset failed for cmd=ffff882f89c2c7c0. qla2xxx [0000:81:00.0]-800f:3: DEVICE RESET FAILED: Task management failed nexus=3:0:2 cmd=ffff882f89c2c7c0. qla2xxx [0000:81:00.0]-8009:3: TARGET RESET ISSUED nexus=3:0:2 cmd=ffff882f89c2c7c0. qla2xxx [0000:81:00.0]-800c:3: do_reset failed for cmd=ffff882f89c2c7c0. qla2xxx [0000:81:00.0]-800f:3: TARGET RESET FAILED: Task management failed nexus=3:0:2 cmd=ffff882f89c2c7c0. qla2xxx [0000:81:00.0]-8012:3: BUS RESET ISSUED nexus=3:0:2. qla2xxx [0000:81:00.0]-802b:3: BUS RESET SUCCEEDED nexus=3:0:2. qla2xxx [0000:81:00.0]-505f:3: Link is operational (8 Gbps). qla2xxx [0000:81:00.0]-8018:3: ADAPTER RESET ISSUED nexus=3:0:2. qla2xxx [0000:81:00.0]-00af:3: Performing ISP error recovery - ha=ffff88bf04d18000. rport-3:0-0: blocked FC remote port time out: removing target and saving binding qla2xxx [0000:81:00.0]-505f:3: Link is operational (8 Gbps). qla2xxx [0000:81:00.0]-8017:3: ADAPTER RESET SUCCEEDED nexus=3:0:2. rport-2:0-0: blocked FC remote port time out: removing target and saving binding sg_rq_end_io: device detached BUG: unable to handle kernel NULL pointer dereference at 00000000000002a8 IP: [<ffffffff8133b268>] __pm_runtime_idle+0x28/0x90 PGD 7e6586f067 PUD 7e5af06067 PMD 0 [1739975.390354] Oops: 0002 [#1] SMP CPU 0 ... Supported: No, Proprietary modules are loaded [1739975.390463] Pid: 27965, comm: ABCD Tainted: PF X 3.0.101-0.29-default #1 HP ProLiant DL580 Gen8 RIP: 0010:[<ffffffff8133b268>] [<ffffffff8133b268>] __pm_runtime_idle+0x28/0x90 RSP: 0018:ffff8839dc1e7c68 EFLAGS: 00010202 RAX: 0000000000000000 RBX: ffff883f0592fc00 RCX: 0000000000000090 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000138 RBP: 0000000000000138 R08: 0000000000000010 R09: ffffffff81bd39d0 R10: 00000000000009c0 R11: ffffffff81025790 R12: 0000000000000001 R13: ffff883022212b80 R14: 0000000000000004 R15: ffff883022212b80 FS: 00007f8e54560720(0000) GS:ffff88407f800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00000000000002a8 CR3: 0000007e6ced6000 CR4: 00000000001407f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process ABCD (pid: 27965, threadinfo ffff8839dc1e6000, task ffff883592e0c640) Stack: ffff883f0592fc00 00000000fffffffa 0000000000000001 ffff883022212b80 ffff883eff772400 ffffffffa03fa309 0000000000000000 0000000000000000 ffffffffa04003a0 ffff883f063196c0 ffff887f0379a930 ffffffff8115ea1e Call Trace: [<ffffffffa03fa309>] st_open+0x129/0x240 [st] [<ffffffff8115ea1e>] chrdev_open+0x13e/0x200 [<ffffffff811588a8>] __dentry_open+0x198/0x310 [<ffffffff81167d74>] do_last+0x1f4/0x800 [<ffffffff81168fe9>] path_openat+0xd9/0x420 [<ffffffff8116946c>] do_filp_open+0x4c/0xc0 [<ffffffff8115a00f>] do_sys_open+0x17f/0x250 [<ffffffff81468d92>] system_call_fastpath+0x16/0x1b [<00007f8e4f617fd0>] 0x7f8e4f617fcf Code: eb d3 90 48 83 ec 28 40 f6 c6 04 48 89 6c 24 08 4c 89 74 24 20 48 89 fd 48 89 1c 24 4c 89 64 24 10 41 89 f6 4c 89 6c 24 18 74 11 <f0> ff 8f 70 01 00 00 0f 94 c0 45 31 ed 84 c0 74 2b 4c 8d a5 a0 RIP [<ffffffff8133b268>] __pm_runtime_idle+0x28/0x90 RSP <ffff8839dc1e7c68> CR2: 00000000000002a8 Analysis reveals the cause of the crash to be due to STp->device being NULL. The pointer was NULLed via scsi_tape_put(STp) when it calls scsi_tape_release(). In st_open() we jump to err_out after scsi_block_when_processing_errors() completes and returns the device as offline (sdev_state was SDEV_DEL): 1180 /* Open the device. Needs to take the BKL only because of incrementing the SCSI host 1181 module count. */ 1182 static int st_open(struct inode *inode, struct file *filp) 1183 { 1184 int i, retval = (-EIO); 1185 int resumed = 0; 1186 struct scsi_tape *STp; 1187 struct st_partstat *STps; 1188 int dev = TAPE_NR(inode); 1189 char *name; ... 1217 if (scsi_autopm_get_device(STp->device) < 0) { 1218 retval = -EIO; 1219 goto err_out; 1220 } 1221 resumed = 1; 1222 if (!scsi_block_when_processing_errors(STp->device)) { 1223 retval = (-ENXIO); 1224 goto err_out; 1225 } ... 1264 err_out: 1265 normalize_buffer(STp->buffer); 1266 spin_lock(&st_use_lock); 1267 STp->in_use = 0; 1268 spin_unlock(&st_use_lock); 1269 scsi_tape_put(STp); <-- STp->device = 0 after this 1270 if (resumed) 1271 scsi_autopm_put_device(STp->device); 1272 return retval; The ref count for the struct scsi_tape had already been reduced to 1 when the .remove method of the st module had been called. The kref_put() in scsi_tape_put() caused scsi_tape_release() to be called: 0266 static void scsi_tape_put(struct scsi_tape *STp) 0267 { 0268 struct scsi_device *sdev = STp->device; 0269 0270 mutex_lock(&st_ref_mutex); 0271 kref_put(&STp->kref, scsi_tape_release); <-- calls this 0272 scsi_device_put(sdev); 0273 mutex_unlock(&st_ref_mutex); 0274 } In scsi_tape_release() the struct scsi_device in the struct scsi_tape gets set to NULL: 4273 static void scsi_tape_release(struct kref *kref) 4274 { 4275 struct scsi_tape *tpnt = to_scsi_tape(kref); 4276 struct gendisk *disk = tpnt->disk; 4277 4278 tpnt->device = NULL; <<<---- where the dev is nulled 4279 4280 if (tpnt->buffer) { 4281 normalize_buffer(tpnt->buffer); 4282 kfree(tpnt->buffer->reserved_pages); 4283 kfree(tpnt->buffer); 4284 } 4285 4286 disk->private_data = NULL; 4287 put_disk(disk); 4288 kfree(tpnt); 4289 return; 4290 } Although the problem was reported on SLES11.3 the problem appears in linux-next as well. The crash is fixed by reordering the code so we no longer access the struct scsi_tape after the kref_put() is done on it in st_open(). Signed-off-by: Shane Seymour <shane.seymour@hp.com> Signed-off-by: Darren Lavender <darren.lavender@hp.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.com> Acked-by: Kai Mäkisara <kai.makisara@kolumbus.fi> Cc: stable@vger.kernel.org Signed-off-by: James Bottomley <JBottomley@Odin.com>

When I tested my new patches, I found that page pointer which is used for setting page_owner information is changed. This is because page pointer is used to set new migratetype in loop. After this work, page pointer could be out of bound. If this wrong pointer is used for page_owner, access violation happens. Below is error message that I got. BUG: unable to handle kernel paging request at 0000000000b00018 IP: [<ffffffff81025f30>] save_stack_address+0x30/0x40 PGD 1af2d067 PUD 166e0067 PMD 0 Oops: 0002 [#1] SMP ...snip... Call Trace: print_context_stack+0xcf/0x100 dump_trace+0x15f/0x320 save_stack_trace+0x2f/0x50 __set_page_owner+0x46/0x70 __isolate_free_page+0x1f7/0x210 split_free_page+0x21/0xb0 isolate_freepages_block+0x1e2/0x410 compaction_alloc+0x22d/0x2d0 migrate_pages+0x289/0x8b0 compact_zone+0x409/0x880 compact_zone_order+0x6d/0x90 try_to_compact_pages+0x110/0x210 __alloc_pages_direct_compact+0x3d/0xe6 __alloc_pages_nodemask+0x6cd/0x9a0 alloc_pages_current+0x91/0x100 runtest_store+0x296/0xa50 simple_attr_write+0xbd/0xe0 __vfs_write+0x28/0xf0 vfs_write+0xa9/0x1b0 SyS_write+0x46/0xb0 system_call_fastpath+0x16/0x75 This patch fixes this error by moving up set_page_owner(). Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

On an absent filesystem (one served by another server), we need to be able to handle requests for certain attributest (like fs_locations, so the client can find out which server does have the filesystem), but others we can't. We forgot to take that into account when adding another attribute bitmask work for the SECURITY_LABEL attribute. There an export entry with the "refer" option can result in: [ 88.414272] kernel BUG at fs/nfsd/nfs4xdr.c:2249! [ 88.414828] invalid opcode: 0000 [#1] SMP [ 88.415368] Modules linked in: rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache nfsd xfs libcrc32c iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi iosf_mbi ppdev btrfs coretemp crct10dif_pclmul crc32_pclmul crc32c_intel xor ghash_clmulni_intel raid6_pq vmw_balloon parport_pc parport i2c_piix4 shpchp vmw_vmci acpi_cpufreq auth_rpcgss nfs_acl lockd grace sunrpc vmwgfx drm_kms_helper ttm drm mptspi mptscsih serio_raw mptbase e1000 scsi_transport_spi ata_generic pata_acpi [last unloaded: nfsd] [ 88.417827] CPU: 0 PID: 2116 Comm: nfsd Not tainted 4.0.7-300.fc22.x86_64 #1 [ 88.418448] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/20/2014 [ 88.419093] task: ffff880079146d50 ti: ffff8800785d8000 task.ti: ffff8800785d8000 [ 88.419729] RIP: 0010:[<ffffffffa04b3c10>] [<ffffffffa04b3c10>] nfsd4_encode_fattr+0x820/0x1f00 [nfsd] [ 88.420376] RSP: 0000:ffff8800785db998 EFLAGS: 00010206 [ 88.421027] RAX: 0000000000000001 RBX: 000000000018091a RCX: ffff88006668b980 [ 88.421676] RDX: 00000000fffef7fc RSI: 0000000000000000 RDI: ffff880078d05000 [ 88.422315] RBP: ffff8800785dbb58 R08: ffff880078d043f8 R09: ffff880078d4a000 [ 88.422968] R10: 0000000000010000 R11: 0000000000000002 R12: 0000000000b0a23a [ 88.423612] R13: ffff880078d05000 R14: ffff880078683100 R15: ffff88006668b980 [ 88.424295] FS: 0000000000000000(0000) GS:ffff88007c600000(0000) knlGS:0000000000000000 [ 88.424944] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 88.425597] CR2: 00007f40bc370f90 CR3: 0000000035af5000 CR4: 00000000001407f0 [ 88.426285] Stack: [ 88.426921] ffff8800785dbaa8 ffffffffa049e4af ffff8800785dba08 ffffffff813298f0 [ 88.427585] ffff880078683300 ffff8800769b0de8 0000089d00000001 0000000087f805e0 [ 88.428228] ffff880000000000 ffff880079434a00 0000000000000000 ffff88006668b980 [ 88.428877] Call Trace: [ 88.429527] [<ffffffffa049e4af>] ? exp_get_by_name+0x7f/0xb0 [nfsd] [ 88.430168] [<ffffffff813298f0>] ? inode_doinit_with_dentry+0x210/0x6a0 [ 88.430807] [<ffffffff8123833e>] ? d_lookup+0x2e/0x60 [ 88.431449] [<ffffffff81236133>] ? dput+0x33/0x230 [ 88.432097] [<ffffffff8123f214>] ? mntput+0x24/0x40 [ 88.432719] [<ffffffff812272b2>] ? path_put+0x22/0x30 [ 88.433340] [<ffffffffa049ac87>] ? nfsd_cross_mnt+0xb7/0x1c0 [nfsd] [ 88.433954] [<ffffffffa04b54e0>] nfsd4_encode_dirent+0x1b0/0x3d0 [nfsd] [ 88.434601] [<ffffffffa04b5330>] ? nfsd4_encode_getattr+0x40/0x40 [nfsd] [ 88.435172] [<ffffffffa049c991>] nfsd_readdir+0x1c1/0x2a0 [nfsd] [ 88.435710] [<ffffffffa049a530>] ? nfsd_direct_splice_actor+0x20/0x20 [nfsd] [ 88.436447] [<ffffffffa04abf30>] nfsd4_encode_readdir+0x120/0x220 [nfsd] [ 88.437011] [<ffffffffa04b58cd>] nfsd4_encode_operation+0x7d/0x190 [nfsd] [ 88.437566] [<ffffffffa04aa6dd>] nfsd4_proc_compound+0x24d/0x6f0 [nfsd] [ 88.438157] [<ffffffffa0496103>] nfsd_dispatch+0xc3/0x220 [nfsd] [ 88.438680] [<ffffffffa006f0cb>] svc_process_common+0x43b/0x690 [sunrpc] [ 88.439192] [<ffffffffa0070493>] svc_process+0x103/0x1b0 [sunrpc] [ 88.439694] [<ffffffffa0495a57>] nfsd+0x117/0x190 [nfsd] [ 88.440194] [<ffffffffa0495940>] ? nfsd_destroy+0x90/0x90 [nfsd] [ 88.440697] [<ffffffff810bb728>] kthread+0xd8/0xf0 [ 88.441260] [<ffffffff810bb650>] ? kthread_worker_fn+0x180/0x180 [ 88.441762] [<ffffffff81789e58>] ret_from_fork+0x58/0x90 [ 88.442322] [<ffffffff810bb650>] ? kthread_worker_fn+0x180/0x180 [ 88.442879] Code: 0f 84 93 05 00 00 83 f8 ea c7 85 a0 fe ff ff 00 00 27 30 0f 84 ba fe ff ff 85 c0 0f 85 a5 fe ff ff e9 e3 f9 ff ff 0f 1f 44 00 00 <0f> 0b 66 0f 1f 44 00 00 be 04 00 00 00 4c 89 ef 4c 89 8d 68 fe [ 88.444052] RIP [<ffffffffa04b3c10>] nfsd4_encode_fattr+0x820/0x1f00 [nfsd] [ 88.444658] RSP <ffff8800785db998> [ 88.445232] ---[ end trace 6cb9d0487d94a29f ]--- Signed-off-by: Kinglong Mee <kinglongmee@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Daniel Borkmann says: ==================== Couple of classifier fixes This fixes a couple of panics in the form of (analogous for cls_flow{,er}): [ 912.759276] BUG: unable to handle kernel NULL pointer dereference at (null) [ 912.759373] IP: [<ffffffffa09d4d6d>] cls_bpf_change+0x23d/0x268 [cls_bpf] [ 912.759441] PGD 8783c067 PUD 5f684067 PMD 0 [ 912.759491] Oops: 0002 [#1] SMP DEBUG_PAGEALLOC [ 912.759543] Modules linked in: cls_bpf(E) act_gact [...] [ 912.772734] CPU: 3 PID: 10489 Comm: tc Tainted: G W E 4.2.0-rc2+ torvalds#73 [ 912.775004] Hardware name: Apple Inc. MacBookAir5,1/Mac-66F35F19FE2A0D05, BIOS MBA51.88Z.00EF.B02.1211271028 11/27/2012 [ 912.777327] task: ffff88025eaa8000 ti: ffff88005f734000 task.ti: ffff88005f734000 [ 912.779662] RIP: 0010:[<ffffffffa09d4d6d>] [<ffffffffa09d4d6d>] cls_bpf_change+0x23d/0x268 [cls_bpf] [ 912.781991] RSP: 0018:ffff88005f7379c8 EFLAGS: 00010286 [ 912.784183] RAX: ffff880201d64e48 RBX: 0000000000000000 RCX: ffff880201d64e40 [ 912.786402] RDX: 0000000000000000 RSI: ffffffffa09d51c0 RDI: ffffffffa09d51a6 [ 912.788625] RBP: ffff88005f737a68 R08: 0000000000000000 R09: 0000000000000000 [ 912.790854] R10: 0000000000000001 R11: 0000000000000001 R12: ffff880078ab5a80 [ 912.793082] R13: ffff880232b31570 R14: ffff88005f737ae0 R15: ffff8801e215d1d0 [ 912.795181] FS: 00007f3c0c80d740(0000) GS:ffff880265400000(0000) knlGS:0000000000000000 [ 912.797281] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 912.799402] CR2: 0000000000000000 CR3: 000000005460f000 CR4: 00000000001407e0 [ 912.799403] Stack: [ 912.799407] ffffffff00000000 ffff88023ea18000 000000005f737a08 0000000000000000 [ 912.799415] ffffffff81f06140 ffff880201d64e40 0000000000000000 ffff88023ea1804c [ 912.799418] 0000000000000000 ffff88023ea18044 ffff88023ea18030 ffff88023ea18038 [ 912.799418] Call Trace: [ 912.799437] [<ffffffff816d5685>] tc_ctl_tfilter+0x335/0x910 [ 912.799443] [<ffffffff813622a8>] ? security_capable+0x48/0x60 [ 912.799448] [<ffffffff816b90e5>] rtnetlink_rcv_msg+0x95/0x240 [ 912.799454] [<ffffffff810f612d>] ? trace_hardirqs_on+0xd/0x10 [ 912.799456] [<ffffffff816b902f>] ? rtnetlink_rcv+0x1f/0x40 [ 912.799459] [<ffffffff816b902f>] ? rtnetlink_rcv+0x1f/0x40 [ 912.799461] [<ffffffff816b9050>] ? rtnetlink_rcv+0x40/0x40 [ 912.799464] [<ffffffff816df38f>] netlink_rcv_skb+0xaf/0xc0 [ 912.799467] [<ffffffff816b903e>] rtnetlink_rcv+0x2e/0x40 [ 912.799469] [<ffffffff816deaef>] netlink_unicast+0xef/0x1b0 [ 912.799471] [<ffffffff816defa0>] netlink_sendmsg+0x3f0/0x620 [ 912.799476] [<ffffffff81687028>] sock_sendmsg+0x38/0x50 [ 912.799479] [<ffffffff81687938>] ___sys_sendmsg+0x288/0x290 [ 912.799482] [<ffffffff810f7852>] ? __lock_acquire+0x572/0x2050 [ 912.799488] [<ffffffff810265db>] ? native_sched_clock+0x2b/0x90 [ 912.799493] [<ffffffff8116135f>] ? __audit_syscall_entry+0xaf/0x100 [ 912.799497] [<ffffffff8116135f>] ? __audit_syscall_entry+0xaf/0x100 [ 912.799501] [<ffffffff8112aa19>] ? current_kernel_time+0x69/0xd0 [ 912.799505] [<ffffffff81266f16>] ? __fget_light+0x66/0x90 [ 912.799508] [<ffffffff81688812>] __sys_sendmsg+0x42/0x80 [ 912.799510] [<ffffffff81688862>] SyS_sendmsg+0x12/0x20 [ 912.799515] [<ffffffff817f9a6e>] entry_SYSCALL_64_fastpath+0x12/0x76 [ 912.799540] Code: 4d 88 49 8b 57 08 48 89 51 08 49 8b 57 10 48 89 c8 48 83 c0 08 48 89 51 10 48 8b 51 10 48 c7 c6 c0 51 9d a0 48 c7 c7 a6 51 9d a0 <48> 89 02 48 8b 51 08 48 89 42 08 48 b8 00 02 20 00 00 00 ad de [ 912.799544] RIP [<ffffffffa09d4d6d>] cls_bpf_change+0x23d/0x268 [cls_bpf] [ 912.799544] RSP <ffff88005f7379c8> [ 912.799545] CR2: 0000000000000000 [ 912.807380] ---[ end trace a6440067cfdc7c29 ]--- I've split them into 3 patches, so they can be backported easier when needed. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>

The ehci_init_driver is used to initialize hcd APIs for each ehci controller driver, it is designed to be called only one time and before driver register is called. The current design will cause ehci_init_driver is called multiple times at probe process, it will cause hc_driver's initialization affect current running hcd. We run out NULL pointer dereference problem when one hcd is started by module_init, and the other is started by otg thread at SMP platform. The reason for this problem is ehci_init_driver will do memory copy for current uniform hc_driver, and this memory copy will do memset (as 0) first, so when the first hcd is running usb_add_hcd, and the second hcd may clear the uniform hc_driver's space (at ehci_init_driver), then the first hcd will meet NULL pointer at the same time. See below two logs: LOG_1: ci_hdrc ci_hdrc.0: EHCI Host Controller ci_hdrc ci_hdrc.0: new USB bus registered, assigned bus number 1 ci_hdrc ci_hdrc.1: doesn't support gadget Unable to handle kernel NULL pointer dereference at virtual address 00000014 pgd = 80004000 [00000014] *pgd=00000000 Internal error: Oops: 805 [#1] PREEMPT SMP ARM Modules linked in: CPU: 0 PID: 108 Comm: kworker/u8:2 Not tainted 3.14.38-222193-g24b2734-dirty torvalds#25 Workqueue: ci_otg ci_otg_work task: d839ec00 ti: d8400000 task.ti: d8400000 PC is at ehci_run+0x4c/0x284 LR is at _raw_spin_unlock_irqrestore+0x28/0x54 pc : [<8041f9a0>] lr : [<8070ea84>] psr: 60000113 sp : d8401e30 ip : 00000000 fp : d8004400 r10: 00000001 r9 : 00000001 r8 : 00000000 r7 : 00000000 r6 : d8419940 r5 : 80dd24c0 r4 : d8419800 r3 : 8001d060 r2 : 00000000 r1 : 00000001 r0 : 00000000 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel Control: 10c53c7d Table: 1000404a DAC: 00000015 Process kworker/u8:2 (pid: 108, stack limit = 0xd8400238) Stack: (0xd8401e30 to 0xd8402000) 1e20: d87523c0 d8401e48 66667562 d8419800 1e40: 00000000 00000000 d8419800 00000000 00000000 00000000 d84198b0 8040fcdc 1e60: 00000000 80dd320c d8477610 d8419c00 d803d010 d8419800 00000000 00000000 1e80: d8004400 00000000 d8400008 80431494 80431374 d803d100 d803d010 d803d1ac 1ea0: 00000000 80432428 804323d4 d803d100 00000001 80435eb8 80e0d0bc d803d100 1ec0: 00000006 80436458 00000000 d803d100 80e92ec8 80436f44 d803d010 d803d100 1ee0: d83fde00 8043292c d8752710 d803d1f4 d803d010 8042ddfc 8042ddb8 d83f3b00 1f00: d803d1f4 80042b60 00000000 00000003 00000001 00000001 80054598 d83f3b00 1f20: d8004400 d83f3b18 d8004414 d8400000 80e3957b 00000089 d8004400 80043814 1f40: d839ec00 00000000 d83fcd80 d83f3b00 800436e4 00000000 00000000 00000000 1f60: 00000000 80048f34 00000000 00000000 00000000 d83f3b00 00000000 00000000 1f80: d8401f80 d8401f80 00000000 00000000 d8401f90 d8401f90 d8401fac d83fcd80 1fa0: 80048e68 00000000 00000000 8000e538 00000000 00000000 00000000 00000000 1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1fe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000 [<8041f9a0>] (ehci_run) from [<8040fcdc>] (usb_add_hcd+0x248/0x6e8) [<8040fcdc>] (usb_add_hcd) from [<80431494>] (host_start+0x120/0x2e4) [<80431494>] (host_start) from [<80432428>] (ci_otg_start_host+0x54/0xbc) [<80432428>] (ci_otg_start_host) from [<80435eb8>] (otg_set_protocol+0xa4/0xd0) [<80435eb8>] (otg_set_protocol) from [<80436458>] (otg_set_state+0x574/0xc58) [<80436458>] (otg_set_state) from [<80436f44>] (otg_statemachine+0x408/0x46c) [<80436f44>] (otg_statemachine) from [<8043292c>] (ci_otg_fsm_work+0x3c/0x190) [<8043292c>] (ci_otg_fsm_work) from [<8042ddfc>] (ci_otg_work+0x44/0x1c4) [<8042ddfc>] (ci_otg_work) from [<80042b60>] (process_one_work+0xf4/0x35c) [<80042b60>] (process_one_work) from [<80043814>] (worker_thread+0x130/0x3bc) [<80043814>] (worker_thread) from [<80048f34>] (kthread+0xcc/0xe4) [<80048f34>] (kthread) from [<8000e538>] (ret_from_fork+0x14/0x3c) Code: e5953018 e3530000 0a000000 e12fff33 (e5878014) LOG_2: ci_hdrc ci_hdrc.0: EHCI Host Controller ci_hdrc ci_hdrc.0: new USB bus registered, assigned bus number 1 ci_hdrc ci_hdrc.1: doesn't support gadget Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = 80004000 [00000000] *pgd=00000000 In Online 00:00ternal e Offline rror: Oops: 80000005 [#1] PREEMPT SMP ARM Modules linked in: CPU: 0 PID: 108 Comm: kworker/u8:2 Not tainted 3.14.38-02007-g24b2734-dirty torvalds#127 Workque Online 00:00ue: ci_o Offline tg ci_otg_work Online 00:00task: d8 Offline 39ec00 ti: d83ea000 task.ti: d83ea000 PC is at 0x0 LR is at usb_add_hcd+0x248/0x6e8 pc : [<00000000>] lr : [<8040f644>] psr: 60000113 sp : d83ebe60 ip : 00000000 fp : d8004400 r10: 00000001 r9 : 00000001 r8 : d85fd4b0 r7 : 00000000 r6 : 00000000 r5 : 00000000 r4 : d85fd400 r3 : 00000000 r2 : d85fd4f4 r1 : 80410178 r0 : d85fd400 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel Control: 10c53c7d Table: 1000404a DAC: 00000015 Process kworker/u8:2 (pid: 108, stack limit = 0xd83ea238) Stack: (0xd83ebe60 to 0xd83ec000) be60: 00000000 80dd920c d8654e10 d85fd800 d803e010 d85fd400 00000000 00000000 be80: d8004400 00000000 d83ea008 80430e34 80430d14 d803e100 d803e010 d803e1ac bea0: 00000000 80431dc8 80431d74 d803e100 00000001 80435858 80e130bc d803e100 bec0: 00000006 80435df8 00000000 d803e100 80e98ec8 804368e4 d803e010 d803e100 bee0: d86e8100 804322cc d86cf050 d803e1f4 d803e010 8042d79c 8042d758 d83cf900 bf00: d803e1f4 80042b78 00000000 00000003 00000001 00000001 800545e8 d83cf900 bf20: d8004400 d83cf918 d8004414 d83ea000 80e3f57b 00000089 d8004400 8004382c bf40: d839ec00 00000000 d8393780 d83cf900 800436fc 00000000 00000000 00000000 bf60: 00000000 80048f50 80e019f4 00000000 0000264c d83cf900 00000000 00000000 bf80: d83ebf80 d83ebf80 00000000 00000000 d83ebf90 d83ebf90 d83ebfac d8393780 bfa0: 80048e84 00000000 00000000 8000e538 00000000 00000000 00000000 00000000 bfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 bfe0: 00000000 00000000 00000000 00000000 00000013 00000000 ee66e85d 133ebd03 [<804 Online 00:000f644>] Offline (usb_add_hcd) from [<80430e34>] (host_start+0x120/0x2e4) [<80430e34>] (host_start) from [<80431dc8>] (ci_otg_start_host+0x54/0xbc) [<80431dc8>] (ci_otg_start_host) from [<80435858>] (otg_set_protocol+0xa4/0xd0) [<80435858>] (otg_set_protocol) from [<80435df8>] (otg_set_state+0x574/0xc58) [<80435df8>] (otg_set_state) from [<804368e4>] (otg_statemachine+0x408/0x46c) [<804368e4>] (otg_statemachine) from [<804322cc>] (ci_otg_fsm_work+0x3c/0x190) [<804322cc>] (ci_otg_fsm_work) from [<8042d79c>] (ci_otg_work+0x44/0x1c4) [<8042d79c>] (ci_otg_work) from [<80042b78>] (process_one_work+0xf4/0x35c) [<80042b78>] (process_one_work) from [<8004382c>] (worker_thread+0x130/0x3bc) [<8004382c>] (worker_thread) from [<80048f50>] (kthread+0xcc/0xe4) [<80048f50>] (kthread) from [<8000e538>] (ret_from_fork+0x14/0x3c) Code: bad PC value Cc: Jun Li <jun.li@freescale.com> Cc: <stable@vger.kernel.org> Cc: Alan Stern <stern@rowland.harvard.edu> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Peter Chen <peter.chen@freescale.com>

Kirill A. Shutemov says: This simple test-case trigers few locking asserts in kernel: int main(int argc, char **argv) { unsigned int block_size = 16 * 4096; struct nl_mmap_req req = { .nm_block_size = block_size, .nm_block_nr = 64, .nm_frame_size = 16384, .nm_frame_nr = 64 * block_size / 16384, }; unsigned int ring_size; int fd; fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_GENERIC); if (setsockopt(fd, SOL_NETLINK, NETLINK_RX_RING, &req, sizeof(req)) < 0) exit(1); if (setsockopt(fd, SOL_NETLINK, NETLINK_TX_RING, &req, sizeof(req)) < 0) exit(1); ring_size = req.nm_block_nr * req.nm_block_size; mmap(NULL, 2 * ring_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); return 0; } +++ exited with 0 +++ BUG: sleeping function called from invalid context at /home/kas/git/public/linux-mm/kernel/locking/mutex.c:616 in_atomic(): 1, irqs_disabled(): 0, pid: 1, name: init 3 locks held by init/1: #0: (reboot_mutex){+.+...}, at: [<ffffffff81080959>] SyS_reboot+0xa9/0x220 #1: ((reboot_notifier_list).rwsem){.+.+..}, at: [<ffffffff8107f379>] __blocking_notifier_call_chain+0x39/0x70 #2: (rcu_callback){......}, at: [<ffffffff810d32e0>] rcu_do_batch.isra.49+0x160/0x10c0 Preemption disabled at:[<ffffffff8145365f>] __delay+0xf/0x20 CPU: 1 PID: 1 Comm: init Not tainted 4.1.0-00009-gbddf4c4818e0 torvalds#253 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS Debian-1.8.2-1 04/01/2014 ffff88017b3d8000 ffff88027bc03c38 ffffffff81929ceb 0000000000000102 0000000000000000 ffff88027bc03c68 ffffffff81085a9d 0000000000000002 ffffffff81ca2a20 0000000000000268 0000000000000000 ffff88027bc03c98 Call Trace: <IRQ> [<ffffffff81929ceb>] dump_stack+0x4f/0x7b [<ffffffff81085a9d>] ___might_sleep+0x16d/0x270 [<ffffffff81085bed>] __might_sleep+0x4d/0x90 [<ffffffff8192e96f>] mutex_lock_nested+0x2f/0x430 [<ffffffff81932fed>] ? _raw_spin_unlock_irqrestore+0x5d/0x80 [<ffffffff81464143>] ? __this_cpu_preempt_check+0x13/0x20 [<ffffffff8182fc3d>] netlink_set_ring+0x1ed/0x350 [<ffffffff8182e000>] ? netlink_undo_bind+0x70/0x70 [<ffffffff8182fe20>] netlink_sock_destruct+0x80/0x150 [<ffffffff817e484d>] __sk_free+0x1d/0x160 [<ffffffff817e49a9>] sk_free+0x19/0x20 [..] Cong Wang says: We can't hold mutex lock in a rcu callback, [..] Thomas Graf says: The socket should be dead at this point. It might be simpler to add a netlink_release_ring() function which doesn't require locking at all. Reported-by: "Kirill A. Shutemov" <kirill@shutemov.name> Diagnosed-by: Cong Wang <cwang@twopensource.com> Suggested-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>

…_tree_block() fail When read_tree_block() failed, we can see following dmesg: [ 134.371389] BUG: unable to handle kernel NULL pointer dereference at 0000000000000063 [ 134.372236] IP: [<ffffffff813a4a51>] free_extent_buffer+0x21/0x90 [ 134.372236] PGD 0 [ 134.372236] Oops: 0000 [#1] SMP [ 134.372236] Modules linked in: [ 134.372236] CPU: 0 PID: 2289 Comm: mount Not tainted 4.2.0-rc1_HEAD_c65b99f046843d2455aa231747b5a07a999a9f3d_+ torvalds#115 [ 134.372236] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5.1-0-g8936dbb-20141113_115728-nilsson.home.kraxel.org 04/01/2014 [ 134.372236] task: ffff88003b6e1a00 ti: ffff880011e60000 task.ti: ffff880011e60000 [ 134.372236] RIP: 0010:[<ffffffff813a4a51>] [<ffffffff813a4a51>] free_extent_buffer+0x21/0x90 ... [ 134.372236] Call Trace: [ 134.372236] [<ffffffff81379aa1>] free_root_extent_buffers+0x91/0xb0 [ 134.372236] [<ffffffff81379c3d>] free_root_pointers+0x17d/0x190 [ 134.372236] [<ffffffff813801b0>] open_ctree+0x1ca0/0x25b0 [ 134.372236] [<ffffffff8144d017>] ? disk_name+0x97/0xb0 [ 134.372236] [<ffffffff813558aa>] btrfs_mount+0x8fa/0xab0 ... Reason: read_tree_block() changed to return error number on fail, and this value(not NULL) is set to tree_root->node, then subsequent code will run to: free_root_pointers() ->free_root_extent_buffers() ->free_extent_buffer() ->atomic_read((extent_buffer *)(-E_XXX)->refs); and trigger above error. Fix: Set tree_root->node to NULL on fail to make error_handle code happy. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>

In dev_queue_xmit() net_cls protected with rcu-bh. [ 270.730026] =============================== [ 270.730029] [ INFO: suspicious RCU usage. ] [ 270.730033] 4.2.0-rc3+ #2 Not tainted [ 270.730036] ------------------------------- [ 270.730040] include/linux/cgroup.h:353 suspicious rcu_dereference_check() usage! [ 270.730041] other info that might help us debug this: [ 270.730043] rcu_scheduler_active = 1, debug_locks = 1 [ 270.730045] 2 locks held by dhclient/748: [ 270.730046] #0: (rcu_read_lock_bh){......}, at: [<ffffffff81682b70>] __dev_queue_xmit+0x50/0x960 [ 270.730085] #1: (&qdisc_tx_lock){+.....}, at: [<ffffffff81682d60>] __dev_queue_xmit+0x240/0x960 [ 270.730090] stack backtrace: [ 270.730096] CPU: 0 PID: 748 Comm: dhclient Not tainted 4.2.0-rc3+ #2 [ 270.730098] Hardware name: OpenStack Foundation OpenStack Nova, BIOS Bochs 01/01/2011 [ 270.730100] 0000000000000001 ffff8800bafeba58 ffffffff817ad487 0000000000000007 [ 270.730103] ffff880232a0a780 ffff8800bafeba88 ffffffff810ca4f2 ffff88022fb23e00 [ 270.730105] ffff880232a0a780 ffff8800bafebb68 ffff8800bafebb68 ffff8800bafebaa8 [ 270.730108] Call Trace: [ 270.730121] [<ffffffff817ad487>] dump_stack+0x4c/0x65 [ 270.730148] [<ffffffff810ca4f2>] lockdep_rcu_suspicious+0xe2/0x120 [ 270.730153] [<ffffffff816a62d2>] task_cls_state+0x92/0xa0 [ 270.730158] [<ffffffffa00b534f>] cls_cgroup_classify+0x4f/0x120 [cls_cgroup] [ 270.730164] [<ffffffff816aac74>] tc_classify_compat+0x74/0xc0 [ 270.730166] [<ffffffff816ab573>] tc_classify+0x33/0x90 [ 270.730170] [<ffffffffa00bcb0a>] htb_enqueue+0xaa/0x4a0 [sch_htb] [ 270.730172] [<ffffffff81682e26>] __dev_queue_xmit+0x306/0x960 [ 270.730174] [<ffffffff81682b70>] ? __dev_queue_xmit+0x50/0x960 [ 270.730176] [<ffffffff816834a3>] dev_queue_xmit_sk+0x13/0x20 [ 270.730185] [<ffffffff81787770>] dev_queue_xmit+0x10/0x20 [ 270.730187] [<ffffffff8178b91c>] packet_snd.isra.62+0x54c/0x760 [ 270.730190] [<ffffffff8178be25>] packet_sendmsg+0x2f5/0x3f0 [ 270.730203] [<ffffffff81665245>] ? sock_def_readable+0x5/0x190 [ 270.730210] [<ffffffff817b64bb>] ? _raw_spin_unlock+0x2b/0x40 [ 270.730216] [<ffffffff8173bcbc>] ? unix_dgram_sendmsg+0x5cc/0x640 [ 270.730219] [<ffffffff8165f367>] sock_sendmsg+0x47/0x50 [ 270.730221] [<ffffffff8165f42f>] sock_write_iter+0x7f/0xd0 [ 270.730232] [<ffffffff811fd4c7>] __vfs_write+0xa7/0xf0 [ 270.730234] [<ffffffff811fe5b8>] vfs_write+0xb8/0x190 [ 270.730236] [<ffffffff811fe8c2>] SyS_write+0x52/0xb0 [ 270.730239] [<ffffffff817b6bae>] entry_SYSCALL_64_fastpath+0x12/0x76 Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: David S. Miller <davem@davemloft.net>

The cgroup attaches inode->i_wb via mark_inode_dirty and when set_page_writeback is called, __inc_wb_stat() updates i_wb's stat. So, we need to explicitly call set_page_dirty->__mark_inode_dirty in prior to any writebacking pages. This patch should resolve the following kernel panic reported by Andreas Reis. https://bugzilla.kernel.org/show_bug.cgi?id=101801 --- Comment #2 from Andreas Reis <andreas.reis@gmail.com> --- BUG: unable to handle kernel NULL pointer dereference at 00000000000000a8 IP: [<ffffffff8149deea>] __percpu_counter_add+0x1a/0x90 PGD 2951ff067 PUD 2df43f067 PMD 0 Oops: 0000 [#1] PREEMPT SMP Modules linked in: CPU: 7 PID: 10356 Comm: gcc Tainted: G W 4.2.0-1-cu #1 Hardware name: Gigabyte Technology Co., Ltd. G1.Sniper M5/G1.Sniper M5, BIOS T01 02/03/2015 task: ffff880295044f80 ti: ffff880295140000 task.ti: ffff880295140000 RIP: 0010:[<ffffffff8149deea>] [<ffffffff8149deea>] __percpu_counter_add+0x1a/0x90 RSP: 0018:ffff880295143ac8 EFLAGS: 00010082 RAX: 0000000000000003 RBX: ffffea000a526d40 RCX: 0000000000000001 RDX: 0000000000000020 RSI: 0000000000000001 RDI: 0000000000000088 RBP: ffff880295143ae8 R08: 0000000000000000 R09: ffff88008f69bb30 R10: 00000000fffffffa R11: 0000000000000000 R12: 0000000000000088 R13: 0000000000000001 R14: ffff88041d099000 R15: ffff880084a205d0 FS: 00007f8549374700(0000) GS:ffff88042f3c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000000a8 CR3: 000000033e1d5000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: 0000000000000000 ffffea000a526d40 ffff880084a20738 ffff880084a20750 ffff880295143b48 ffffffff811cc91e ffff880000000000 0000000000000296 0000000000000000 ffff880417090198 0000000000000000 ffffea000a526d40 Call Trace: [<ffffffff811cc91e>] __test_set_page_writeback+0xde/0x1d0 [<ffffffff813fee87>] do_write_data_page+0xe7/0x3a0 [<ffffffff813faeea>] gc_data_segment+0x5aa/0x640 [<ffffffff813fb0b8>] do_garbage_collect+0x138/0x150 [<ffffffff813fb3fe>] f2fs_gc+0x1be/0x3e0 [<ffffffff81405541>] f2fs_balance_fs+0x81/0x90 [<ffffffff813ee357>] f2fs_unlink+0x47/0x1d0 [<ffffffff81239329>] vfs_unlink+0x109/0x1b0 [<ffffffff8123e3d7>] do_unlinkat+0x287/0x2c0 [<ffffffff8123ebc6>] SyS_unlink+0x16/0x20 [<ffffffff81942e2e>] entry_SYSCALL_64_fastpath+0x12/0x71 Code: 41 5e 5d c3 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 55 49 89 f5 41 54 49 89 fc 53 48 83 ec 08 65 ff 05 e6 d9 b6 7e <48> 8b 47 20 48 63 ca 65 8b 18 48 63 db 48 01 f3 48 39 cb 7d 0a RIP [<ffffffff8149deea>] __percpu_counter_add+0x1a/0x90 RSP <ffff880295143ac8> CR2: 00000000000000a8 ---[ end trace 5132449a58ed93a3 ]--- note: gcc[10356] exited with preempt_count 2 Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Florian Westphal says: ==================== inet: ip defrag bug fixes Johan Schuijt and Frank Schreuder reported crash and softlockup after the inet workqueue eviction change: general protection fault: 0000 [#1] SMP CPU: 0 PID: 4 Comm: kworker/0:0 Not tainted 3.18.18-transip-1.5 #1 Workqueue: events inet_frag_worker task: ffff880224935130 ti: ffff880224938000 task.ti: ffff880224938000 RIP: 0010:[<ffffffff8149288c>] [<ffffffff8149288c>] inet_evict_bucket+0xfc/0x160 RSP: 0018:ffff88022493bd58 EFLAGS: 00010286 RAX: ffff88021f4f3e80 RBX: dead000000100100 RCX: 000000000000006b RDX: 000000000000006c RSI: ffff88021f4f3e80 RDI: dead0000001000a8 RBP: 0000000000000002 R08: ffff880222273900 R09: ffff880036e49200 R10: ffff8800c6e86500 R11: ffff880036f45500 R12: ffffffff81a87100 R13: ffff88022493bd70 R14: 0000000000000000 R15: ffff8800c9b26280 [..] Call Trace: [<ffffffff814929e0>] ? inet_frag_worker+0x60/0x210 [<ffffffff8107e3a2>] ? process_one_work+0x142/0x3b0 [<ffffffff8107eb94>] ? worker_thread+0x114/0x440 [..] A second issue results in softlockup since the evictor may restart the eviction loop for a (potentially) unlimited number of times while local softirqs are disabled. Frank reports that test system remained stable for 14 hours of testing (before, crash occured within half an hour in their setup). ==================== Signed-off-by: David S. Miller <davem@davemloft.net>

The commit 98b5a0f introduces jumbo frame support, but also it assumes that macb_config present which is not always true. The configuration without macb_config fails to boot. Unable to handle kernel NULL pointer dereference at virtual address 00000010 ptbr = 90350000 pgd = 00000000 Oops: Kernel access of bad area, sig: 11 [#1] FRAME_POINTER chip: 0x01f:0x1e82 rev 2 Modules linked in: CPU: 0 PID: 1 Comm: swapper Not tainted 4.2.0-rc3-next-20150723+ torvalds#13 task: 91c26000 ti: 91c28000 task.ti: 91c28000 PC is at macb_probe+0x140/0x61c Fixes: 98b5a0f (net: macb: Add support for jumbo frames) Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>

Stephen Powell reported the following crash on a z890 machine: Kernel BUG at 00000000001219d0 [verbose debug info unavailable] illegal operation: 0001 ilc:3 [#1] SMP Krnl PSW : 0704e00180000000 00000000001219d0 (init_cache_level+0x38/0xe0) R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 EA:3 Krnl Code: 00000000001219c2: a7840056 brc 8,121a6e 00000000001219c6: a7190000 lghi %r1,0 #00000000001219ca: eb101000004c ecag %r1,%r0,0(%r1) >00000000001219d0: a7390000 lghi %r3,0 00000000001219d4: e310f0a00024 stg %r1,160(%r15) 00000000001219da: a7080000 lhi %r0,0 00000000001219de: a7b9f000 lghi %r11,-4096 00000000001219e2: c0a0002899d9 larl %r10,634d94 Call Trace: [<0000000000478ee2>] detect_cache_attributes+0x2a/0x2b8 [<000000000097c9b0>] cacheinfo_sysfs_init+0x60/0xc8 [<00000000001001c0>] do_one_initcall+0x98/0x1c8 [<000000000094fdc2>] kernel_init_freeable+0x212/0x2d8 [<000000000062352e>] kernel_init+0x26/0x118 [<000000000062fd2e>] kernel_thread_starter+0x6/0xc The illegal operation was executed because of a missing facility check, which should have made sure that the ECAG execution would only be executed on machines which have the general-instructions-extension facility installed. Reported-and-tested-by: Stephen Powell <zlinuxman@wowway.com> Cc: stable@vger.kernel.org # v4.0+ Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Traceback in -next due to commit 'clockevents/drivers/sh_tmu: Migrate to new 'set-state' interface'. Commit ("clockevents/drivers/sh_tmu: Migrate to new 'set-state' interface") in -next causes the following traceback. This is seen with qemu runs for the sh target. ------------[ cut here ]------------ WARNING: at drivers/clocksource/sh_tmu.c:202 Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 4.2.0-rc3-next-20150720 #1 task: 8c411ed8 ti: 8c40e000 task.ti: 8c40e000 PC is at sh_tmu_disable+0x40/0x60 PR is at sh_tmu_clock_event_shutdown+0x8/0x20 PC : 8c271220 SP : 8c40ff10 SR : 400081f1 TEA : 00000000 R0 : 8c271240 R1 : 8fc08cfc R2 : 00000000 R3 : 3fffffff R4 : 8fc08c00 R5 : 00000001 R6 : 00000002 R7 : ffffffff R8 : 00000001 R9 : 8fc08c20 R10 : 00000000 R11 : 00000000 R12 : 8c012820 R13 : 00000000 R14 : 00000000 MACH: 3b9ac9ff MACL: 80000000 GBR : 00000000 PR : 8c271248 Call trace: [<8c065836>] clockevents_switch_state+0x16/0x60 [<8c06588c>] clockevents_shutdown+0xc/0x40 [<8c066330>] tick_check_new_device+0x90/0xc0 [<8c065556>] clockevents_register_device+0x56/0x120 [<8c0662a0>] tick_check_new_device+0x0/0xc0 [<8c27167a>] sh_tmu_probe+0x29a/0x4e0 [<8c18a994>] kasprintf+0x14/0x20 [<8c442782>] early_platform_driver_probe+0x20e/0x2bc [<8c1fade0>] platform_match+0x0/0x100 [<8c33babc>] printk+0x0/0x24 [<8c434892>] start_kernel+0x32e/0x574 [<8c33babc>] printk+0x0/0x24 [<8c17d320>] strlen+0x0/0x58 [<8c43430c>] unknown_bootoption+0x0/0x1e0 [<8c011024>] _stext+0x24/0x30 ---[ end trace cb88537fdc8fa200 ]--- Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>

The probe error path for this driver, for all intents and purposes, is the talitos_remove() function due to the common "goto err_out". Without this patch applied, talitos_remove() will panic under these two conditions: 1. If the RNG device hasn't been registered via talitos_register_rng() prior to entry into talitos_remove(), then the attempt to unregister the RNG "device" will cause a panic. 2. If the priv->chan array has not been allocated prior to entry into talitos_remove(), then the per-channel FIFO cleanup will panic because of the dereference of that NULL "array". Both of the above scenarios occur if talitos_probe_irq() fails. This patch resolves issue #1 by introducing a boolean to mask the hwrng_unregister() call in talitos_unregister_rng() if RNG device registration was unsuccessful. It resolves issue #2 by checking that priv->chan is not NULL in the per-channel FIFO cleanup for loop. Signed-off-by: Aaron Sierra <asierra@xes-inc.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

…on monotonic timers I noticed for non-monotonic timers in timer_list, some of the output looked a little confusing. For example: #1: <0000000000000000>, posix_timer_fn, S:01, hrtimer_start_range_ns, leap-a-day/2360 # expires at 1434412800000000000-1434412800000000000 nsecs [in 1434410725062375469 to 1434410725062375469 nsecs] You'll note the relative time till the expiration "[in xxx to yyy nsecs]" is incorrect. This is because its printing the delta between CLOCK_MONOTONIC time to the CLOCK_REALTIME expiration. This patch fixes this issue by adding the clock offset to the "now" time which we use to calculate the delta. Cc: Prarit Bhargava <prarit@redhat.com> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Jan Kara <jack@suse.cz> Cc: Jiri Bohac <jbohac@suse.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Shuah Khan <shuahkh@osg.samsung.com> Signed-off-by: John Stultz <john.stultz@linaro.org>

srp_destroy_qp is designed to indicate we are safe to continue with freeing the channel resources by modifying the qp error state, posting a dummy wr on the queue-pair and waiting for it to flush. This also holds for the channel registration pool as we are unmapping the memory region when handling a scsi response. Destroying the channel registration pool before we make sure we processed all the inflight IO might introduce a use-after-free of the registration pool. This use-after-free is demonstrated in the stack trace below where srp is trying to unmap a used FMR after the fmr_pool was already destroyed. general protection fault: 0000 [#1] SMP RIP: 0010:[<ffffffff8151121b>] [<ffffffff8151121b>] _raw_spin_lock_irqsave+0x1b/0x50 Call Trace: [<ffffffffa055d88a>] ib_fmr_pool_unmap+0x1a/0xb0 [ib_core] [<ffffffffa06c00ed>] srp_unmap_data.isra.28+0x17d/0x250 [ib_srp] [<ffffffffa06c01eb>] srp_free_req+0x2b/0x60 [ib_srp] [<ffffffffa06c0c94>] srp_recv_completion+0x174/0x580 [ib_srp] [<ffffffffa04580fe>] mlx4_eq_int+0x4de/0xe50 [mlx4_core] [<ffffffffa0458b00>] mlx4_msi_x_interrupt+0x10/0x20 [mlx4_core] [<ffffffff810abc45>] handle_irq_event_percpu+0x35/0x1b0 [<ffffffff810abdf2>] handle_irq_event+0x32/0x50 [<ffffffff810ae5cf>] handle_edge_irq+0x6f/0x120 [<ffffffff8100455a>] handle_irq+0x1a/0x30 [<ffffffff8151b475>] do_IRQ+0x45/0xb0 [<ffffffff8151162d>] common_interrupt+0x6d/0x6d [<ffffffff813e4d2f>] cpuidle_enter_state+0x4f/0xc0 [<ffffffff813e4e6c>] cpuidle_idle_call+0xcc/0x210 [<ffffffff8100b9ea>] arch_cpu_idle+0xa/0x30 [<ffffffff810ab1e1>] cpu_startup_entry+0xe1/0x270 [<ffffffff81030b3a>] start_secondary+0x21a/0x2c0 Reported-by: Eliott Kespi <eliottk@mellanox.com> Signed-off-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Doug Ledford <dledford@redhat.com>

Tony Luck found on his setup, if memory block size 512M will cause crash during booting. BUG: unable to handle kernel paging request at ffffea0074000020 IP: get_nid_for_pfn+0x17/0x40 PGD 128ffcb067 PUD 128ffc9067 PMD 0 Oops: 0000 [#1] SMP Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.2.0-rc8 #1 ... Call Trace: ? register_mem_sect_under_node+0x66/0xe0 register_one_node+0x17b/0x240 ? pci_iommu_alloc+0x6e/0x6e topology_init+0x3c/0x95 do_one_initcall+0xcd/0x1f0 The system has non continuous RAM address: BIOS-e820: [mem 0x0000001300000000-0x0000001cffffffff] usable BIOS-e820: [mem 0x0000001d70000000-0x0000001ec7ffefff] usable BIOS-e820: [mem 0x0000001f00000000-0x0000002bffffffff] usable BIOS-e820: [mem 0x0000002c18000000-0x0000002d6fffefff] usable BIOS-e820: [mem 0x0000002e00000000-0x00000039ffffffff] usable So there are start sections in memory block not present. For example: memory block : [0x2c18000000, 0x2c20000000) 512M first three sections are not present. The current register_mem_sect_under_node() assume first section is present, but memory block section number range [start_section_nr, end_section_nr] would include not present section. For arch that support vmemmap, we don't setup memmap for struct page area within not present sections area. So skip the pfn range that belong to absent section. [akpm@linux-foundation.org: simplification] [rientjes@google.com: more simplification] Fixes: bdee237 ("x86: mm: Use 2GB memory block size on large memory x86-64 systems") Fixes: 982792c ("x86, mm: probe memory block size for generic x86 64bit") Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: David Rientjes <rientjes@google.com> Reported-by: Tony Luck <tony.luck@intel.com> Tested-by: Tony Luck <tony.luck@intel.com> Cc: Greg KH <greg@kroah.com> Cc: Ingo Molnar <mingo@elte.hu> Tested-by: David Rientjes <rientjes@google.com> Cc: <stable@vger.kernel.org> [3.15+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

PID: 614 TASK: ffff882a739da580 CPU: 3 COMMAND: "ocfs2dc" #0 [ffff882ecc3759b0] machine_kexec at ffffffff8103b35d #1 [ffff882ecc375a20] crash_kexec at ffffffff810b95b5 #2 [ffff882ecc375af0] oops_end at ffffffff815091d8 #3 [ffff882ecc375b20] die at ffffffff8101868b #4 [ffff882ecc375b50] do_trap at ffffffff81508bb0 #5 [ffff882ecc375ba0] do_invalid_op at ffffffff810165e5 torvalds#6 [ffff882ecc375c40] invalid_op at ffffffff815116fb [exception RIP: ocfs2_ci_checkpointed+208] RIP: ffffffffa0a7e940 RSP: ffff882ecc375cf0 RFLAGS: 00010002 RAX: 0000000000000001 RBX: 000000000000654b RCX: ffff8812dc83f1f8 RDX: 00000000000017d9 RSI: ffff8812dc83f1f8 RDI: ffffffffa0b2c318 RBP: ffff882ecc375d20 R8: ffff882ef6ecfa60 R9: ffff88301f272200 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffffffffffff R13: ffff8812dc83f4f0 R14: 0000000000000000 R15: ffff8812dc83f1f8 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 torvalds#7 [ffff882ecc375d28] ocfs2_check_meta_downconvert at ffffffffa0a7edbd [ocfs2] torvalds#8 [ffff882ecc375d38] ocfs2_unblock_lock at ffffffffa0a84af8 [ocfs2] torvalds#9 [ffff882ecc375dc8] ocfs2_process_blocked_lock at ffffffffa0a85285 [ocfs2] torvalds#10 [ffff882ecc375e18] ocfs2_downconvert_thread_do_work at ffffffffa0a85445 [ocfs2] torvalds#11 [ffff882ecc375e68] ocfs2_downconvert_thread at ffffffffa0a854de [ocfs2] torvalds#12 [ffff882ecc375ee8] kthread at ffffffff81090da7 torvalds#13 [ffff882ecc375f48] kernel_thread_helper at ffffffff81511884 assert is tripped because the tran is not checkpointed and the lock level is PR. Some time ago, chmod command had been executed. As result, the following call chain left the inode cluster lock in PR state, latter on causing the assert. system_call_fastpath -> my_chmod -> sys_chmod -> sys_fchmodat -> notify_change -> ocfs2_setattr -> posix_acl_chmod -> ocfs2_iop_set_acl -> ocfs2_set_acl -> ocfs2_acl_set_mode Here is how. 1119 int ocfs2_setattr(struct dentry *dentry, struct iattr *attr) 1120 { 1247 ocfs2_inode_unlock(inode, 1); <<< WRONG thing to do. .. 1258 if (!status && attr->ia_valid & ATTR_MODE) { 1259 status = posix_acl_chmod(inode, inode->i_mode); 519 posix_acl_chmod(struct inode *inode, umode_t mode) 520 { .. 539 ret = inode->i_op->set_acl(inode, acl, ACL_TYPE_ACCESS); 287 int ocfs2_iop_set_acl(struct inode *inode, struct posix_acl *acl, ... 288 { 289 return ocfs2_set_acl(NULL, inode, NULL, type, acl, NULL, NULL); 224 int ocfs2_set_acl(handle_t *handle, 225 struct inode *inode, ... 231 { .. 252 ret = ocfs2_acl_set_mode(inode, di_bh, 253 handle, mode); 168 static int ocfs2_acl_set_mode(struct inode *inode, struct buffer_head ... 170 { 183 if (handle == NULL) { >>> BUG: inode lock not held in ex at this point <<< 184 handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb), 185 OCFS2_INODE_UPDATE_CREDITS); ocfs2_setattr.#1247 we unlock and at #1259 call posix_acl_chmod. When we reach ocfs2_acl_set_mode.torvalds#181 and do trans, the inode cluster lock is not held in EX mode (it should be). How this could have happended? We are the lock master, were holding lock EX and have released it in ocfs2_setattr.#1247. Note that there are no holders of this lock at this point. Another node needs the lock in PR, and we downconvert from EX to PR. So the inode lock is PR when do the trans in ocfs2_acl_set_mode.torvalds#184. The trans stays in core (not flushed to disc). Now another node want the lock in EX, downconvert thread gets kicked (the one that tripped assert abovt), finds an unflushed trans but the lock is not EX (it is PR). If the lock was at EX, it would have flushed the trans ocfs2_ci_checkpointed -> ocfs2_start_checkpoint before downconverting (to NULL) for the request. ocfs2_setattr must not drop inode lock ex in this code path. If it does, takes it again before the trans, say in ocfs2_set_acl, another cluster node can get in between, execute another setattr, overwriting the one in progress on this node, resulting in a mode acl size combo that is a mix of the two. Orabug: 20189959 Signed-off-by: Tariq Saeed <tariq.x.saeed@oracle.com> Reviewed-by: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Joseph Qi <joseph.qi@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

There was no verification that an underlying transport exists when creating a connection, this would cause dereferencing a NULL ptr. It might happen on sockets that weren't properly bound before attempting to send a message, which will cause a NULL ptr deref: [135546.047719] kasan: GPF could be caused by NULL-ptr deref or user memory accessgeneral protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC KASAN [135546.051270] Modules linked in: [135546.051781] CPU: 4 PID: 15650 Comm: trinity-c4 Not tainted 4.2.0-next-20150902-sasha-00041-gbaa1222-dirty #2527 [135546.053217] task: ffff8800835bc000 ti: ffff8800bc708000 task.ti: ffff8800bc708000 [135546.054291] RIP: __rds_conn_create (net/rds/connection.c:194) [135546.055666] RSP: 0018:ffff8800bc70fab0 EFLAGS: 00010202 [135546.056457] RAX: dffffc0000000000 RBX: 0000000000000f2c RCX: ffff8800835bc000 [135546.057494] RDX: 0000000000000007 RSI: ffff8800835bccd8 RDI: 0000000000000038 [135546.058530] RBP: ffff8800bc70fb18 R08: 0000000000000001 R09: 0000000000000000 [135546.059556] R10: ffffed014d7a3a23 R11: ffffed014d7a3a21 R12: 0000000000000000 [135546.060614] R13: 0000000000000001 R14: ffff8801ec3d0000 R15: 0000000000000000 [135546.061668] FS: 00007faad4ffb700(0000) GS:ffff880252000000(0000) knlGS:0000000000000000 [135546.062836] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [135546.063682] CR2: 000000000000846a CR3: 000000009d137000 CR4: 00000000000006a0 [135546.064723] Stack: [135546.065048] ffffffffafe2055c ffffffffafe23fc1 ffffed00493097bf ffff8801ec3d0008 [135546.066247] 0000000000000000 00000000000000d0 0000000000000000 ac194a24c0586342 [135546.067438] 1ffff100178e1f78 ffff880320581b00 ffff8800bc70fdd0 ffff880320581b00 [135546.068629] Call Trace: [135546.069028] ? __rds_conn_create (include/linux/rcupdate.h:856 net/rds/connection.c:134) [135546.069989] ? rds_message_copy_from_user (net/rds/message.c:298) [135546.071021] rds_conn_create_outgoing (net/rds/connection.c:278) [135546.071981] rds_sendmsg (net/rds/send.c:1058) [135546.072858] ? perf_trace_lock (include/trace/events/lock.h:38) [135546.073744] ? lockdep_init (kernel/locking/lockdep.c:3298) [135546.074577] ? rds_send_drop_to (net/rds/send.c:976) [135546.075508] ? __might_fault (./arch/x86/include/asm/current.h:14 mm/memory.c:3795) [135546.076349] ? __might_fault (mm/memory.c:3795) [135546.077179] ? rds_send_drop_to (net/rds/send.c:976) [135546.078114] sock_sendmsg (net/socket.c:611 net/socket.c:620) [135546.078856] SYSC_sendto (net/socket.c:1657) [135546.079596] ? SYSC_connect (net/socket.c:1628) [135546.080510] ? trace_dump_stack (kernel/trace/trace.c:1926) [135546.081397] ? ring_buffer_unlock_commit (kernel/trace/ring_buffer.c:2479 kernel/trace/ring_buffer.c:2558 kernel/trace/ring_buffer.c:2674) [135546.082390] ? trace_buffer_unlock_commit (kernel/trace/trace.c:1749) [135546.083410] ? trace_event_raw_event_sys_enter (include/trace/events/syscalls.h:16) [135546.084481] ? do_audit_syscall_entry (include/trace/events/syscalls.h:16) [135546.085438] ? trace_buffer_unlock_commit (kernel/trace/trace.c:1749) [135546.085515] rds_ib_laddr_check(): addr 36.74.25.172 ret -99 node type -1 Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>

On old ARM chips, unaligned accesses to memory are not trapped and fixed. On module load, symbols are relocated, and the relocation of __bug_table symbols is done on a u32 basis. Yet the section is not aligned to a multiple of 4 address, but to a multiple of 2. This triggers an Oops on pxa architecture, where address 0xbf0021ea is the first relocation in the __bug_table section : apply_relocate(): pxa3xx_nand: section 13 reloc 0 sym '' Unable to handle kernel paging request at virtual address bf0021ea pgd = e1cd0000 [bf0021ea] *pgd=c1cce851, *pte=c1cde04f, *ppte=c1cde01f Internal error: Oops: 23 [#1] ARM Modules linked in: CPU: 0 PID: 606 Comm: insmod Not tainted 4.2.0-rc8-next-20150828-cm-x300+ torvalds#887 Hardware name: CM-X300 module task: e1c68700 ti: e1c3e000 task.ti: e1c3e000 PC is at apply_relocate+0x2f4/0x3d4 LR is at 0xbf0021ea pc : [<c000e7c8>] lr : [<bf0021ea>] psr: 80000013 sp : e1c3fe30 ip : 60000013 fp : e49e8c60 r10: e49e8fa8 r9 : 00000000 r8 : e49e7c58 r7 : e49e8c38 r6 : e49e8a58 r5 : e49e8920 r4 : e49e8918 r3 : bf0021ea r2 : bf007034 r1 : 00000000 r0 : bf000000 Flags: Nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 0000397f Table: c1cd0018 DAC: 00000051 Process insmod (pid: 606, stack limit = 0xe1c3e198) [<c000e7c8>] (apply_relocate) from [<c005ce5c>] (load_module+0x1248/0x1f5c) [<c005ce5c>] (load_module) from [<c005dc54>] (SyS_init_module+0xe4/0x170) [<c005dc54>] (SyS_init_module) from [<c000a420>] (ret_fast_syscall+0x0/0x38) Fix this by ensuring entries in __bug_table are all aligned to at least of multiple of 4. This transforms a module section __bug_table as : - [12] __bug_table PROGBITS 00000000 002232 000018 00 A 0 0 1 + [12] __bug_table PROGBITS 00000000 002232 000018 00 A 0 0 4 Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The renesas-irqc interrupt controller is cascaded to the GIC. Hence when propagating wake-up settings to its parent interrupt controller, the following lockdep warning is printed: ============================================= [ INFO: possible recursive locking detected ] 4.2.0-ape6evm-10725-g50fcd7643c034198 torvalds#280 Not tainted --------------------------------------------- s2ram/1072 is trying to acquire lock: (&irq_desc_lock_class){-.-...}, at: [<c008d3fc>] __irq_get_desc_lock+0x58/0x98 but task is already holding lock: (&irq_desc_lock_class){-.-...}, at: [<c008d3fc>] __irq_get_desc_lock+0x58/0x98 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&irq_desc_lock_class); lock(&irq_desc_lock_class); *** DEADLOCK *** May be due to missing lock nesting notation 6 locks held by s2ram/1072: #0: (sb_writers#7){.+.+.+}, at: [<c012eb14>] __sb_start_write+0xa0/0xa8 #1: (&of->mutex){+.+.+.}, at: [<c019396c>] kernfs_fop_write+0x4c/0x1bc #2: (s_active#24){.+.+.+}, at: [<c0193974>] kernfs_fop_write+0x54/0x1bc #3: (pm_mutex){+.+.+.}, at: [<c008213c>] pm_suspend+0x10c/0x510 #4: (&dev->mutex){......}, at: [<c02af3c4>] __device_suspend+0xdc/0x2cc #5: (&irq_desc_lock_class){-.-...}, at: [<c008d3fc>] __irq_get_desc_lock+0x58/0x98 stack backtrace: CPU: 0 PID: 1072 Comm: s2ram Not tainted 4.2.0-ape6evm-10725-g50fcd7643c034198 torvalds#280 Hardware name: Generic R8A73A4 (Flattened Device Tree) [<c0018078>] (unwind_backtrace) from [<c00144f0>] (show_stack+0x10/0x14) [<c00144f0>] (show_stack) from [<c0451f14>] (dump_stack+0x88/0x98) [<c0451f14>] (dump_stack) from [<c007b29c>] (__lock_acquire+0x15cc/0x20e4) [<c007b29c>] (__lock_acquire) from [<c007c6e0>] (lock_acquire+0xac/0x12c) [<c007c6e0>] (lock_acquire) from [<c0457c00>] (_raw_spin_lock_irqsave+0x40/0x54) [<c0457c00>] (_raw_spin_lock_irqsave) from [<c008d3fc>] (__irq_get_desc_lock+0x58/0x98) [<c008d3fc>] (__irq_get_desc_lock) from [<c008ebbc>] (irq_set_irq_wake+0x20/0xf8) [<c008ebbc>] (irq_set_irq_wake) from [<c0260770>] (irqc_irq_set_wake+0x20/0x4c) [<c0260770>] (irqc_irq_set_wake) from [<c008ec28>] (irq_set_irq_wake+0x8c/0xf8) [<c008ec28>] (irq_set_irq_wake) from [<c02cb8c0>] (gpio_keys_suspend+0x74/0xc0) [<c02cb8c0>] (gpio_keys_suspend) from [<c02ae8cc>] (dpm_run_callback+0x54/0x124) Avoid this false positive by using a separate lockdep class for IRQC interrupts. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Magnus Damm <magnus.damm@gmail.com> Cc: Jason Cooper <jason@lakedaemon.net> Link: http://lkml.kernel.org/r/1441798974-25716-2-git-send-email-geert%2Brenesas@glider.be Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

The renesas-intc-irqpin interrupt controller is cascaded to the GIC. Hence when propagating wake-up settings to its parent interrupt controller, the following lockdep warning is printed: ============================================= [ INFO: possible recursive locking detected ] 4.2.0-armadillo-10725-g50fcd7643c034198 torvalds#781 Not tainted --------------------------------------------- s2ram/1179 is trying to acquire lock: (&irq_desc_lock_class){-.-...}, at: [<c005bb54>] __irq_get_desc_lock+0x78/0x94 but task is already holding lock: (&irq_desc_lock_class){-.-...}, at: [<c005bb54>] __irq_get_desc_lock+0x78/0x94 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&irq_desc_lock_class); lock(&irq_desc_lock_class); *** DEADLOCK *** May be due to missing lock nesting notation 7 locks held by s2ram/1179: #0: (sb_writers#7){.+.+.+}, at: [<c00c9708>] __sb_start_write+0x64/0xb8 #1: (&of->mutex){+.+.+.}, at: [<c0125a00>] kernfs_fop_write+0x78/0x1a0 #2: (s_active#23){.+.+.+}, at: [<c0125a08>] kernfs_fop_write+0x80/0x1a0 #3: (autosleep_lock){+.+.+.}, at: [<c0058244>] pm_autosleep_lock+0x18/0x20 #4: (pm_mutex){+.+.+.}, at: [<c0057e50>] pm_suspend+0x54/0x248 #5: (&dev->mutex){......}, at: [<c0243a20>] __device_suspend+0xdc/0x240 torvalds#6: (&irq_desc_lock_class){-.-...}, at: [<c005bb54>] __irq_get_desc_lock+0x78/0x94 stack backtrace: CPU: 0 PID: 1179 Comm: s2ram Not tainted 4.2.0-armadillo-10725-g50fcd7643c034198 Hardware name: Generic R8A7740 (Flattened Device Tree) [<c00129f4>] (dump_backtrace) from [<c0012bec>] (show_stack+0x18/0x1c) [<c0012bd4>] (show_stack) from [<c03f5d94>] (dump_stack+0x20/0x28) [<c03f5d74>] (dump_stack) from [<c00514d4>] (__lock_acquire+0x67c/0x1b88) [<c0050e58>] (__lock_acquire) from [<c0052df8>] (lock_acquire+0x9c/0xbc) [<c0052d5c>] (lock_acquire) from [<c03fb068>] (_raw_spin_lock_irqsave+0x44/0x58) [<c03fb024>] (_raw_spin_lock_irqsave) from [<c005bb54>] (__irq_get_desc_lock+0x78/0x94 [<c005badc>] (__irq_get_desc_lock) from [<c005c3d8>] (irq_set_irq_wake+0x28/0x100) [<c005c3b0>] (irq_set_irq_wake) from [<c01e50d0>] (intc_irqpin_irq_set_wake+0x24/0x4c) [<c01e50ac>] (intc_irqpin_irq_set_wake) from [<c005c17c>] (set_irq_wake_real+0x3c/0x50 [<c005c140>] (set_irq_wake_real) from [<c005c414>] (irq_set_irq_wake+0x64/0x100) [<c005c3b0>] (irq_set_irq_wake) from [<c02a19b4>] (gpio_keys_suspend+0x60/0xa0) [<c02a1954>] (gpio_keys_suspend) from [<c023b750>] (platform_pm_suspend+0x3c/0x5c) Avoid this false positive by using a separate lockdep class for INTC External IRQ Pin interrupts. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Magnus Damm <magnus.damm@gmail.com> Cc: Jason Cooper <jason@lakedaemon.net> Link: http://lkml.kernel.org/r/1441798974-25716-3-git-send-email-geert%2Brenesas@glider.be Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

The OPP list needs to be protected against concurrent accesses. Using simple RCU read locks does the trick and gets rid of the following lockdep warning: =============================== [ INFO: suspicious RCU usage. ] 4.2.0-next-20150908 #1 Not tainted ------------------------------- drivers/base/power/opp.c:460 Missing rcu_read_lock() or dev_opp_list_lock protection! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 4 locks held by kworker/u8:0/6: #0: ("%s""deferwq"){++++.+}, at: [<c0040d8c>] process_one_work+0x118/0x4bc #1: (deferred_probe_work){+.+.+.}, at: [<c0040d8c>] process_one_work+0x118/0x4bc #2: (&dev->mutex){......}, at: [<c03b8194>] __device_attach+0x20/0x118 #3: (prepare_lock){+.+...}, at: [<c054bc08>] clk_prepare_lock+0x10/0xf8 stack backtrace: CPU: 2 PID: 6 Comm: kworker/u8:0 Not tainted 4.2.0-next-20150908 #1 Hardware name: NVIDIA Tegra SoC (Flattened Device Tree) Workqueue: deferwq deferred_probe_work_func [<c001802c>] (unwind_backtrace) from [<c00135a4>] (show_stack+0x10/0x14) [<c00135a4>] (show_stack) from [<c02a8418>] (dump_stack+0x94/0xd4) [<c02a8418>] (dump_stack) from [<c03c6f6c>] (dev_pm_opp_find_freq_ceil+0x108/0x114) [<c03c6f6c>] (dev_pm_opp_find_freq_ceil) from [<c0551a3c>] (dfll_calculate_rate_request+0xb8/0x170) [<c0551a3c>] (dfll_calculate_rate_request) from [<c0551b10>] (dfll_clk_round_rate+0x1c/0x2c) [<c0551b10>] (dfll_clk_round_rate) from [<c054de2c>] (clk_calc_new_rates+0x1b8/0x228) [<c054de2c>] (clk_calc_new_rates) from [<c054e44c>] (clk_core_set_rate_nolock+0x44/0xac) [<c054e44c>] (clk_core_set_rate_nolock) from [<c054e4d8>] (clk_set_rate+0x24/0x34) [<c054e4d8>] (clk_set_rate) from [<c0512460>] (tegra124_cpufreq_probe+0x120/0x230) [<c0512460>] (tegra124_cpufreq_probe) from [<c03b9cbc>] (platform_drv_probe+0x44/0xac) [<c03b9cbc>] (platform_drv_probe) from [<c03b84c8>] (driver_probe_device+0x218/0x304) [<c03b84c8>] (driver_probe_device) from [<c03b69b0>] (bus_for_each_drv+0x60/0x94) [<c03b69b0>] (bus_for_each_drv) from [<c03b8228>] (__device_attach+0xb4/0x118) ata1: SATA link down (SStatus 0 SControl 300) [<c03b8228>] (__device_attach) from [<c03b77c8>] (bus_probe_device+0x88/0x90) [<c03b77c8>] (bus_probe_device) from [<c03b7be8>] (deferred_probe_work_func+0x58/0x8c) [<c03b7be8>] (deferred_probe_work_func) from [<c0040dfc>] (process_one_work+0x188/0x4bc) [<c0040dfc>] (process_one_work) from [<c004117c>] (worker_thread+0x4c/0x4f4) [<c004117c>] (worker_thread) from [<c0047230>] (kthread+0xe4/0xf8) [<c0047230>] (kthread) from [<c000f7d0>] (ret_from_fork+0x14/0x24) Signed-off-by: Thierry Reding <treding@nvidia.com> Fixes: c4fe70a ("clk: tegra: Add closed loop support for the DFLL") [vince.h@nvidia.com: Unlock rcu on error path] Signed-off-by: Vince Hsu <vince.h@nvidia.com> [sboyd@codeaurora.org: Dropped second hunk that nested the rcu read lock unnecessarily] Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

…ap_device_late_init Kernel fails to boot 50% of times (form build to build) with RT-patchset applied due to the following race - on late boot stages deferred_probe_work_func->omap_hsmmc_probe races with omap_device_late_ini. The same issue has been reported now on linux-next (4.3) by Keerthy [1] late_initcall - deferred_probe_initcal() tries to re-probe all pending driver's probe. - later on, some driver is probing in this case It's cpsw.c (but could be any other drivers) cpsw_init - platform_driver_register - really_probe - driver_bound - driver_deferred_probe_trigger and boot proceed. So, at this moment we have deferred_probe_work_func scheduled. late_initcall_sync - omap_device_late_init - omap_device_idle CPU1 CPU2 - deferred_probe_work_func - really_probe - omap_hsmmc_probe - pm_runtime_get_sync late_initcall_sync - omap_device_late_init if (od->_driver_status != BUS_NOTIFY_BOUND_DRIVER) { if (od->_state == OMAP_DEVICE_STATE_ENABLED) { - omap_device_idle [ops - IP is disabled] - [fail] - pm_runtime_put_sync - omap_hsmmc_runtime_suspend [ooops!] == log == omap_hsmmc 480b4000.mmc: unable to get vmmc regulator -517 davinci_mdio 48485000.mdio: davinci mdio revision 1.6 davinci_mdio 48485000.mdio: detected phy mask fffffff3 libphy: 48485000.mdio: probed davinci_mdio 48485000.mdio: phy[2]: device 48485000.mdio:02, driver unknown davinci_mdio 48485000.mdio: phy[3]: device 48485000.mdio:03, driver unknown omap_hsmmc 480b4000.mmc: unable to get vmmc regulator -517 cpsw 48484000.ethernet: Detected MACID = b4:99:4c:c7:d2:48 cpsw 48484000.ethernet: cpsw: Detected MACID = b4:99:4c:c7:d2:49 hctosys: unable to open rtc device (rtc0) omap_hsmmc 480b4000.mmc: omap_device_late_idle: enabled but no driver. Idling ldousb: disabling Unhandled fault: imprecise external abort (0x1406) at 0x00000000 [00000000] *pgd=00000000 Internal error: : 1406 [#1] PREEMPT SMP ARM Modules linked in: CPU: 1 PID: 58 Comm: kworker/u4:1 Not tainted 4.1.2-rt1-00467-g6da3c0a-dirty #5 Hardware name: Generic DRA74X (Flattened Device Tree) Workqueue: deferwq deferred_probe_work_func task: ee6ddb00 ti: edd3c000 task.ti: edd3c000 PC is at omap_hsmmc_runtime_suspend+0x1c/0x12c LR is at _od_runtime_suspend+0xc/0x24 pc : [<c0471998>] lr : [<c0029590>] psr: a0000013 sp : edd3dda0 ip : ee6ddb00 fp : c07be540 r10: 00000000 r9 : c07be540 r8 : 00000008 r7 : 00000000 r6 : ee646c10 r5 : ee646c10 r4 : edd79380 r3 : fa0b4100 r2 : 00000000 r1 : 00000000 r0 : ee646c10 Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel Control: 10c5387d Table: 8000406a DAC: 00000015 Process kworker/u4:1 (pid: 58, stack limit = 0xedd3c218) Stack: (0xedd3dda0 to 0xedd3e000) dda0: ee646c70 ee646c10 c0029584 00000000 00000008 c0029590 ee646c70 ee646c10 ddc0: c0029584 c03adfb8 ee646c10 00000004 0000000c c03adff0 ee646c10 00000004 dde0: 0000000c c03ae4ec 00000000 edd3c000 ee646c10 00000004 ee646c70 00000004 de00: fa0b4000 c03aec20 ee6ddb00 ee646c10 00000004 ee646c70 ee646c10 fffffdfb de20: edd79380 00000000 fa0b4000 c03aee90 fffffdfb edd79000 ee646c00 c0474290 de40: 00000000 edda24c0 edd79380 edc81f00 00000000 00000200 00000001 c06dd488 de60: edda3960 ee646c10 ee646c10 c0824cc4 fffffdfb c0880c94 00000002 edc92600 de80: c0836378 c03a7f84 ee646c10 c0824cc4 00000000 c0880c80 c0880c94 c03a6568 dea0: 00000000 ee646c10 c03a66ac ee4f8000 00000000 00000001 edc92600 c03a4b40 dec0: ee404c94 edc83c4c ee646c10 ee646c10 ee646c44 c03a63c4 ee646c10 ee646c10 dee0: c0814448 c03a5aa8 ee646c10 c0814220 edd3c000 c03a5ec0 c0814250 ee6be400 df00: edd3c000 c004e5bc ee6ddb01 00000078 ee6ddb00 ee4f8000 ee6be418 edd3c000 df20: ee4f8028 00000088 c0836045 ee4f8000 ee6be400 c004e928 ee4f8028 00000000 df40: c004e8ec 00000000 ee6bf1c0 ee6be400 c004e8ec 00000000 00000000 00000000 df60: 00000000 c0053450 2e56fa97 00000000 afdffbd7 ee6be400 00000000 00000000 df80: edd3df80 edd3df80 00000000 00000000 edd3df90 edd3df90 edd3dfac ee6bf1c0 dfa0: c0053384 00000000 00000000 c000f668 00000000 00000000 00000000 00000000 dfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 dfe0: 00000000 00000000 00000000 00000000 00000013 00000000 f1fc9d7e febfbdff [<c0471998>] (omap_hsmmc_runtime_suspend) from [<c0029590>] (_od_runtime_suspend+0xc/0x24) [<c0029590>] (_od_runtime_suspend) from [<c03adfb8>] (__rpm_callback+0x24/0x3c) [<c03adfb8>] (__rpm_callback) from [<c03adff0>] (rpm_callback+0x20/0x80) [<c03adff0>] (rpm_callback) from [<c03ae4ec>] (rpm_suspend+0xe4/0x618) [<c03ae4ec>] (rpm_suspend) from [<c03aee90>] (__pm_runtime_idle+0x60/0x80) [<c03aee90>] (__pm_runtime_idle) from [<c0474290>] (omap_hsmmc_probe+0x6bc/0xa7c) [<c0474290>] (omap_hsmmc_probe) from [<c03a7f84>] (platform_drv_probe+0x44/0xa4) [<c03a7f84>] (platform_drv_probe) from [<c03a6568>] (driver_probe_device+0x170/0x2b4) [<c03a6568>] (driver_probe_device) from [<c03a4b40>] (bus_for_each_drv+0x64/0x98) [<c03a4b40>] (bus_for_each_drv) from [<c03a63c4>] (device_attach+0x70/0x88) [<c03a63c4>] (device_attach) from [<c03a5aa8>] (bus_probe_device+0x84/0xac) [<c03a5aa8>] (bus_probe_device) from [<c03a5ec0>] (deferred_probe_work_func+0x58/0x88) [<c03a5ec0>] (deferred_probe_work_func) from [<c004e5bc>] (process_one_work+0x134/0x464) [<c004e5bc>] (process_one_work) from [<c004e928>] (worker_thread+0x3c/0x4fc) [<c004e928>] (worker_thread) from [<c0053450>] (kthread+0xcc/0xe4) [<c0053450>] (kthread) from [<c000f668>] (ret_from_fork+0x14/0x2c) Code: e594302c e593202c e584205c e594302c (e5932128) ---[ end trace 0000000000000002 ]--- The issue happens because omap_device_late_init() do not take into account that some drivers are present, but their probes were not finished successfully and where deferred instead. This is the valid case, and omap_device_late_init() should not idle such devices. To fix this issue, the value of omap_device->_driver_status field should be checked not only for BUS_NOTIFY_BOUND_DRIVER (driver is present and has been bound to device successfully), but also checked for BUS_NOTIFY_BIND_DRIVER (driver about to be bound) - which means driver is present and there was try to bind it to device. [1] http://www.spinics.net/lists/arm-kernel/msg441880.html Cc: Tero Kristo <t-kristo@ti.com> Cc: Keerthy <j-keerthy@ti.com> Tested-by: Keerthy <j-keerthy@ti.com> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com>

If filelayout_decode_layout fail, _filelayout_free_lseg will causes a double freeing of fh_array. [ 1179.279800] BUG: unable to handle kernel NULL pointer dereference at (null) [ 1179.280198] IP: [<ffffffffa027222d>] filelayout_free_fh_array.isra.11+0x1d/0x70 [nfs_layout_nfsv41_files] [ 1179.281010] PGD 0 [ 1179.281443] Oops: 0000 [#1] [ 1179.281831] Modules linked in: nfs_layout_nfsv41_files(OE) nfsv4(OE) nfs(OE) fscache(E) xfs libcrc32c coretemp nfsd crct10dif_pclmul ppdev crc32_pclmul crc32c_intel auth_rpcgss ghash_clmulni_intel nfs_acl lockd vmw_balloon grace sunrpc parport_pc vmw_vmci parport shpchp i2c_piix4 vmwgfx drm_kms_helper ttm drm serio_raw mptspi scsi_transport_spi mptscsih e1000 mptbase ata_generic pata_acpi [last unloaded: fscache] [ 1179.283891] CPU: 0 PID: 13336 Comm: cat Tainted: G OE 4.3.0-rc1-pnfs+ torvalds#244 [ 1179.284323] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/20/2014 [ 1179.285206] task: ffff8800501d48c0 ti: ffff88003e3c4000 task.ti: ffff88003e3c4000 [ 1179.285668] RIP: 0010:[<ffffffffa027222d>] [<ffffffffa027222d>] filelayout_free_fh_array.isra.11+0x1d/0x70 [nfs_layout_nfsv41_files] [ 1179.286612] RSP: 0018:ffff88003e3c77f8 EFLAGS: 00010202 [ 1179.287092] RAX: 0000000000000000 RBX: ffff88001fe78900 RCX: 0000000000000000 [ 1179.287731] RDX: ffffea0000f40760 RSI: ffff88001fe789c8 RDI: ffff88001fe789c0 [ 1179.288383] RBP: ffff88003e3c7810 R08: ffffea0000f40760 R09: 0000000000000000 [ 1179.289170] R10: 0000000000000000 R11: 0000000000000001 R12: ffff88001fe789c8 [ 1179.289959] R13: ffff88001fe789c0 R14: ffff88004ec05a80 R15: ffff88004f935b88 [ 1179.290791] FS: 00007f4e66bb5700(0000) GS:ffffffff81c29000(0000) knlGS:0000000000000000 [ 1179.291580] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1179.292209] CR2: 0000000000000000 CR3: 00000000203f8000 CR4: 00000000001406f0 [ 1179.292731] Stack: [ 1179.293195] ffff88001fe78900 00000000000000d0 ffff88001fe78178 ffff88003e3c7868 [ 1179.293676] ffffffffa0272737 0000000000000001 0000000000000001 ffff88001fe78800 [ 1179.294151] 00000000614fffce ffffffff81727671 ffff88001fe78100 ffff88001fe78100 [ 1179.294623] Call Trace: [ 1179.295092] [<ffffffffa0272737>] filelayout_alloc_lseg+0xa7/0x2d0 [nfs_layout_nfsv41_files] [ 1179.295625] [<ffffffff81727671>] ? out_of_line_wait_on_bit+0x81/0xb0 [ 1179.296133] [<ffffffffa040407e>] pnfs_layout_process+0xae/0x320 [nfsv4] [ 1179.296632] [<ffffffffa03e0a01>] nfs4_proc_layoutget+0x2b1/0x360 [nfsv4] [ 1179.297134] [<ffffffffa0402983>] pnfs_update_layout+0x853/0xb30 [nfsv4] [ 1179.297632] [<ffffffffa039db24>] ? nfs_get_lock_context+0x74/0x170 [nfs] [ 1179.298158] [<ffffffffa0271807>] filelayout_pg_init_read+0x37/0x50 [nfs_layout_nfsv41_files] [ 1179.298834] [<ffffffffa03a72d9>] __nfs_pageio_add_request+0x119/0x460 [nfs] [ 1179.299385] [<ffffffffa03a6bd7>] ? nfs_create_request.part.9+0x37/0x2e0 [nfs] [ 1179.299872] [<ffffffffa03a7cc3>] nfs_pageio_add_request+0xa3/0x1b0 [nfs] [ 1179.300362] [<ffffffffa03a8635>] readpage_async_filler+0x85/0x260 [nfs] [ 1179.300907] [<ffffffff81180cb1>] read_cache_pages+0x91/0xd0 [ 1179.301391] [<ffffffffa03a85b0>] ? nfs_read_completion+0x220/0x220 [nfs] [ 1179.301867] [<ffffffffa03a8dc8>] nfs_readpages+0x128/0x200 [nfs] [ 1179.302330] [<ffffffff81180ef3>] __do_page_cache_readahead+0x203/0x280 [ 1179.302784] [<ffffffff81180dc8>] ? __do_page_cache_readahead+0xd8/0x280 [ 1179.303413] [<ffffffff81181116>] ondemand_readahead+0x1a6/0x2f0 [ 1179.303855] [<ffffffff81181371>] page_cache_sync_readahead+0x31/0x50 [ 1179.304286] [<ffffffff811750a6>] generic_file_read_iter+0x4a6/0x5c0 [ 1179.304711] [<ffffffffa03a0316>] ? __nfs_revalidate_mapping+0x1f6/0x240 [nfs] [ 1179.305132] [<ffffffffa039ccf2>] nfs_file_read+0x52/0xa0 [nfs] [ 1179.305540] [<ffffffff811e343c>] __vfs_read+0xcc/0x100 [ 1179.305936] [<ffffffff811e3d15>] vfs_read+0x85/0x130 [ 1179.306326] [<ffffffff811e4a98>] SyS_read+0x58/0xd0 [ 1179.306708] [<ffffffff8172caaf>] entry_SYSCALL_64_fastpath+0x12/0x76 [ 1179.307094] Code: c4 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 55 41 54 53 8b 07 49 89 f4 85 c0 74 47 48 8b 06 49 89 fd <48> 8b 38 48 85 ff 74 22 31 db eb 0c 48 63 d3 48 8b 3c d0 48 85 [ 1179.308357] RIP [<ffffffffa027222d>] filelayout_free_fh_array.isra.11+0x1d/0x70 [nfs_layout_nfsv41_files] [ 1179.309177] RSP <ffff88003e3c77f8> [ 1179.309582] CR2: 0000000000000000 Signed-off-by: Kinglong Mee <kinglongmee@gmail.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

If we didn't call ATMARP_MKIP before ATMARP_ENCAP the VCC descriptor is non-existant and we'll end up dereferencing a NULL ptr: [1033173.491930] kasan: GPF could be caused by NULL-ptr deref or user memory accessirq event stamp: 123386 [1033173.493678] general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC KASAN [1033173.493689] Modules linked in: [1033173.493697] CPU: 9 PID: 23815 Comm: trinity-c64 Not tainted 4.2.0-next-20150911-sasha-00043-g353d875-dirty #2545 [1033173.493706] task: ffff8800630c4000 ti: ffff880063110000 task.ti: ffff880063110000 [1033173.493823] RIP: clip_ioctl (net/atm/clip.c:320 net/atm/clip.c:689) [1033173.493826] RSP: 0018:ffff880063117a88 EFLAGS: 00010203 [1033173.493828] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 000000000000000c [1033173.493830] RDX: 0000000000000002 RSI: ffffffffb3f10720 RDI: 0000000000000014 [1033173.493832] RBP: ffff880063117b80 R08: ffff88047574d9a4 R09: 0000000000000000 [1033173.493834] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1000c622f53 [1033173.493836] R13: ffff8800cb905500 R14: ffff8808d6da2000 R15: 00000000fffffdfd [1033173.493840] FS: 00007fa56b92d700(0000) GS:ffff880478000000(0000) knlGS:0000000000000000 [1033173.493843] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [1033173.493845] CR2: 0000000000000000 CR3: 00000000630e8000 CR4: 00000000000006a0 [1033173.493855] Stack: [1033173.493862] ffffffffb0b60444 000000000000eaea 0000000041b58ab3 ffffffffb3c3ce32 [1033173.493867] ffffffffb0b6f3e0 ffffffffb0b60444 ffffffffb5ea2e50 1ffff1000c622f5e [1033173.493873] ffff8800630c4cd8 00000000000ee09a ffffffffb3ec4888 ffffffffb5ea2de8 [1033173.493874] Call Trace: [1033173.494108] do_vcc_ioctl (net/atm/ioctl.c:170) [1033173.494113] vcc_ioctl (net/atm/ioctl.c:189) [1033173.494116] svc_ioctl (net/atm/svc.c:605) [1033173.494200] sock_do_ioctl (net/socket.c:874) [1033173.494204] sock_ioctl (net/socket.c:958) [1033173.494244] do_vfs_ioctl (fs/ioctl.c:43 fs/ioctl.c:607) [1033173.494290] SyS_ioctl (fs/ioctl.c:622 fs/ioctl.c:613) [1033173.494295] entry_SYSCALL_64_fastpath (arch/x86/entry/entry_64.S:186) [1033173.494362] Code: fa 48 c1 ea 03 80 3c 02 00 0f 85 50 09 00 00 49 8b 9e 60 06 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 14 48 89 fa 48 c1 ea 03 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 14 09 00 All code ======== 0: fa cli 1: 48 c1 ea 03 shr $0x3,%rdx 5: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 9: 0f 85 50 09 00 00 jne 0x95f f: 49 8b 9e 60 06 00 00 mov 0x660(%r14),%rbx 16: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 1d: fc ff df 20: 48 8d 7b 14 lea 0x14(%rbx),%rdi 24: 48 89 fa mov %rdi,%rdx 27: 48 c1 ea 03 shr $0x3,%rdx 2b:* 0f b6 04 02 movzbl (%rdx,%rax,1),%eax <-- trapping instruction 2f: 48 89 fa mov %rdi,%rdx 32: 83 e2 07 and $0x7,%edx 35: 38 d0 cmp %dl,%al 37: 7f 08 jg 0x41 39: 84 c0 test %al,%al 3b: 0f 85 14 09 00 00 jne 0x955 Code starting with the faulting instruction =========================================== 0: 0f b6 04 02 movzbl (%rdx,%rax,1),%eax 4: 48 89 fa mov %rdi,%rdx 7: 83 e2 07 and $0x7,%edx a: 38 d0 cmp %dl,%al c: 7f 08 jg 0x16 e: 84 c0 test %al,%al 10: 0f 85 14 09 00 00 jne 0x92a [1033173.494366] RIP clip_ioctl (net/atm/clip.c:320 net/atm/clip.c:689) [1033173.494368] RSP <ffff880063117a88> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>

A deadlock trace is seen in netcp driver with lockup detector enabled. The trace log is provided below for reference. This patch fixes the bug by removing the usage of netcp_modules_lock within ndo_ops functions. ndo_{open/close/ioctl)() is already called with rtnl_lock held. So there is no need to hold another mutex for serialization across processes on multiple cores. So remove use of netcp_modules_lock mutex from these ndo ops functions. ndo_set_rx_mode() shouldn't be using a mutex as it is called from atomic context. In the case of ndo_set_rx_mode(), there can be call to this API without rtnl_lock held from an atomic context. As the underlying modules are expected to add address to a hardware table, it is to be protected across concurrent updates and hence a spin lock is used to synchronize the access. Same with ndo_vlan_rx_add_vid() & ndo_vlan_rx_kill_vid(). Probably the netcp_modules_lock is used to protect the module not being removed as part of rmmod. Currently this is not fully implemented and assumes the interface is brought down before doing rmmod of modules. The support for rmmmod while interface is up is expected in a future patch set when additional modules such as pa, qos are added. For now all of the tests such as if up/down, reboot, iperf works fine with this patch applied. Deadlock trace seen with lockup detector enabled is shown below for reference. [ 16.863014] ====================================================== [ 16.869183] [ INFO: possible circular locking dependency detected ] [ 16.875441] 4.1.6-01265-gfb1e101 #1 Tainted: G W [ 16.881176] ------------------------------------------------------- [ 16.887432] ifconfig/1662 is trying to acquire lock: [ 16.892386] (netcp_modules_lock){+.+.+.}, at: [<c03e8110>] netcp_ndo_open+0x168/0x518 [ 16.900321] [ 16.900321] but task is already holding lock: [ 16.906144] (rtnl_mutex){+.+.+.}, at: [<c053a418>] devinet_ioctl+0xf8/0x7e4 [ 16.913206] [ 16.913206] which lock already depends on the new lock. [ 16.913206] [ 16.921372] [ 16.921372] the existing dependency chain (in reverse order) is: [ 16.928844] -> #1 (rtnl_mutex){+.+.+.}: [ 16.932865] [<c06023f0>] mutex_lock_nested+0x68/0x4a8 [ 16.938521] [<c04c5758>] register_netdev+0xc/0x24 [ 16.943831] [<c03e65c0>] netcp_module_probe+0x214/0x2ec [ 16.949660] [<c03e8a54>] netcp_register_module+0xd4/0x140 [ 16.955663] [<c089654c>] keystone_gbe_init+0x10/0x28 [ 16.961233] [<c000977c>] do_one_initcall+0xb8/0x1f8 [ 16.966714] [<c0867e04>] kernel_init_freeable+0x148/0x1e8 [ 16.972720] [<c05f9994>] kernel_init+0xc/0xe8 [ 16.977682] [<c0010038>] ret_from_fork+0x14/0x3c [ 16.982905] -> #0 (netcp_modules_lock){+.+.+.}: [ 16.987619] [<c006eab0>] lock_acquire+0x118/0x320 [ 16.992928] [<c06023f0>] mutex_lock_nested+0x68/0x4a8 [ 16.998582] [<c03e8110>] netcp_ndo_open+0x168/0x518 [ 17.004064] [<c04c48f0>] __dev_open+0xa8/0x10c [ 17.009112] [<c04c4b74>] __dev_change_flags+0x94/0x144 [ 17.014853] [<c04c4c3c>] dev_change_flags+0x18/0x48 [ 17.020334] [<c053a9fc>] devinet_ioctl+0x6dc/0x7e4 [ 17.025729] [<c04a59ec>] sock_ioctl+0x1d0/0x2a8 [ 17.030865] [<c0142844>] do_vfs_ioctl+0x41c/0x688 [ 17.036173] [<c0142ae4>] SyS_ioctl+0x34/0x5c [ 17.041046] [<c000ff60>] ret_fast_syscall+0x0/0x54 [ 17.046441] [ 17.046441] other info that might help us debug this: [ 17.046441] [ 17.054434] Possible unsafe locking scenario: [ 17.054434] [ 17.060343] CPU0 CPU1 [ 17.064862] ---- ---- [ 17.069381] lock(rtnl_mutex); [ 17.072522] lock(netcp_modules_lock); [ 17.078875] lock(rtnl_mutex); [ 17.084532] lock(netcp_modules_lock); [ 17.088366] [ 17.088366] *** DEADLOCK *** [ 17.088366] [ 17.094279] 1 lock held by ifconfig/1662: [ 17.098278] #0: (rtnl_mutex){+.+.+.}, at: [<c053a418>] devinet_ioctl+0xf8/0x7e4 [ 17.105774] [ 17.105774] stack backtrace: [ 17.110124] CPU: 1 PID: 1662 Comm: ifconfig Tainted: G W 4.1.6-01265-gfb1e101 #1 [ 17.118637] Hardware name: Keystone [ 17.122123] [<c00178e4>] (unwind_backtrace) from [<c0013cbc>] (show_stack+0x10/0x14) [ 17.129862] [<c0013cbc>] (show_stack) from [<c05ff450>] (dump_stack+0x84/0xc4) [ 17.137079] [<c05ff450>] (dump_stack) from [<c0068e34>] (print_circular_bug+0x210/0x330) [ 17.145161] [<c0068e34>] (print_circular_bug) from [<c006ab7c>] (validate_chain.isra.35+0xf98/0x13ac) [ 17.154372] [<c006ab7c>] (validate_chain.isra.35) from [<c006da60>] (__lock_acquire+0x52c/0xcc0) [ 17.163149] [<c006da60>] (__lock_acquire) from [<c006eab0>] (lock_acquire+0x118/0x320) [ 17.171058] [<c006eab0>] (lock_acquire) from [<c06023f0>] (mutex_lock_nested+0x68/0x4a8) [ 17.179140] [<c06023f0>] (mutex_lock_nested) from [<c03e8110>] (netcp_ndo_open+0x168/0x518) [ 17.187484] [<c03e8110>] (netcp_ndo_open) from [<c04c48f0>] (__dev_open+0xa8/0x10c) [ 17.195133] [<c04c48f0>] (__dev_open) from [<c04c4b74>] (__dev_change_flags+0x94/0x144) [ 17.203129] [<c04c4b74>] (__dev_change_flags) from [<c04c4c3c>] (dev_change_flags+0x18/0x48) [ 17.211560] [<c04c4c3c>] (dev_change_flags) from [<c053a9fc>] (devinet_ioctl+0x6dc/0x7e4) [ 17.219729] [<c053a9fc>] (devinet_ioctl) from [<c04a59ec>] (sock_ioctl+0x1d0/0x2a8) [ 17.227378] [<c04a59ec>] (sock_ioctl) from [<c0142844>] (do_vfs_ioctl+0x41c/0x688) [ 17.234939] [<c0142844>] (do_vfs_ioctl) from [<c0142ae4>] (SyS_ioctl+0x34/0x5c) [ 17.242242] [<c0142ae4>] (SyS_ioctl) from [<c000ff60>] (ret_fast_syscall+0x0/0x54) [ 17.258855] netcp-1.0 2620110.netcp eth0: Link is Up - 1Gbps/Full - flow control off [ 17.271282] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:616 [ 17.279712] in_atomic(): 1, irqs_disabled(): 0, pid: 1662, name: ifconfig [ 17.286500] INFO: lockdep is turned off. [ 17.290413] Preemption disabled at:[< (null)>] (null) [ 17.295728] [ 17.297214] CPU: 1 PID: 1662 Comm: ifconfig Tainted: G W 4.1.6-01265-gfb1e101 #1 [ 17.305735] Hardware name: Keystone [ 17.309223] [<c00178e4>] (unwind_backtrace) from [<c0013cbc>] (show_stack+0x10/0x14) [ 17.316970] [<c0013cbc>] (show_stack) from [<c05ff450>] (dump_stack+0x84/0xc4) [ 17.324194] [<c05ff450>] (dump_stack) from [<c06023b0>] (mutex_lock_nested+0x28/0x4a8) [ 17.332112] [<c06023b0>] (mutex_lock_nested) from [<c03e9840>] (netcp_set_rx_mode+0x160/0x210) [ 17.340724] [<c03e9840>] (netcp_set_rx_mode) from [<c04c483c>] (dev_set_rx_mode+0x1c/0x28) [ 17.348982] [<c04c483c>] (dev_set_rx_mode) from [<c04c490c>] (__dev_open+0xc4/0x10c) [ 17.356724] [<c04c490c>] (__dev_open) from [<c04c4b74>] (__dev_change_flags+0x94/0x144) [ 17.364729] [<c04c4b74>] (__dev_change_flags) from [<c04c4c3c>] (dev_change_flags+0x18/0x48) [ 17.373166] [<c04c4c3c>] (dev_change_flags) from [<c053a9fc>] (devinet_ioctl+0x6dc/0x7e4) [ 17.381344] [<c053a9fc>] (devinet_ioctl) from [<c04a59ec>] (sock_ioctl+0x1d0/0x2a8) [ 17.388994] [<c04a59ec>] (sock_ioctl) from [<c0142844>] (do_vfs_ioctl+0x41c/0x688) [ 17.396563] [<c0142844>] (do_vfs_ioctl) from [<c0142ae4>] (SyS_ioctl+0x34/0x5c) [ 17.403873] [<c0142ae4>] (SyS_ioctl) from [<c000ff60>] (ret_fast_syscall+0x0/0x54) [ 17.413772] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready udhcpc (v1.20.2) started Sending discover... [ 18.690666] netcp-1.0 2620110.netcp eth0: Link is Up - 1Gbps/Full - flow control off Sending discover... [ 22.250972] netcp-1.0 2620110.netcp eth0: Link is Up - 1Gbps/Full - flow control off [ 22.258721] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready [ 22.265458] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:616 [ 22.273896] in_atomic(): 1, irqs_disabled(): 0, pid: 342, name: kworker/1:1 [ 22.280854] INFO: lockdep is turned off. [ 22.284767] Preemption disabled at:[< (null)>] (null) [ 22.290074] [ 22.291568] CPU: 1 PID: 342 Comm: kworker/1:1 Tainted: G W 4.1.6-01265-gfb1e101 #1 [ 22.300255] Hardware name: Keystone [ 22.303750] Workqueue: ipv6_addrconf addrconf_dad_work [ 22.308895] [<c00178e4>] (unwind_backtrace) from [<c0013cbc>] (show_stack+0x10/0x14) [ 22.316643] [<c0013cbc>] (show_stack) from [<c05ff450>] (dump_stack+0x84/0xc4) [ 22.323867] [<c05ff450>] (dump_stack) from [<c06023b0>] (mutex_lock_nested+0x28/0x4a8) [ 22.331786] [<c06023b0>] (mutex_lock_nested) from [<c03e9840>] (netcp_set_rx_mode+0x160/0x210) [ 22.340394] [<c03e9840>] (netcp_set_rx_mode) from [<c04c9d18>] (__dev_mc_add+0x54/0x68) [ 22.348401] [<c04c9d18>] (__dev_mc_add) from [<c05ab358>] (igmp6_group_added+0x168/0x1b4) [ 22.356580] [<c05ab358>] (igmp6_group_added) from [<c05ad2cc>] (ipv6_dev_mc_inc+0x4f0/0x5a8) [ 22.365019] [<c05ad2cc>] (ipv6_dev_mc_inc) from [<c058f0d0>] (addrconf_dad_work+0x21c/0x33c) [ 22.373460] [<c058f0d0>] (addrconf_dad_work) from [<c0042850>] (process_one_work+0x214/0x8d0) [ 22.381986] [<c0042850>] (process_one_work) from [<c0042f54>] (worker_thread+0x48/0x4bc) [ 22.390071] [<c0042f54>] (worker_thread) from [<c004868c>] (kthread+0xf0/0x108) [ 22.397381] [<c004868c>] (kthread) from [<c0010038>] Trace related to incorrect usage of mutex inside ndo_set_rx_mode [ 24.086066] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:616 [ 24.094506] in_atomic(): 1, irqs_disabled(): 0, pid: 1682, name: ifconfig [ 24.101291] INFO: lockdep is turned off. [ 24.105203] Preemption disabled at:[< (null)>] (null) [ 24.110511] [ 24.112005] CPU: 2 PID: 1682 Comm: ifconfig Tainted: G W 4.1.6-01265-gfb1e101 #1 [ 24.120518] Hardware name: Keystone [ 24.124018] [<c00178e4>] (unwind_backtrace) from [<c0013cbc>] (show_stack+0x10/0x14) [ 24.131772] [<c0013cbc>] (show_stack) from [<c05ff450>] (dump_stack+0x84/0xc4) [ 24.138989] [<c05ff450>] (dump_stack) from [<c06023b0>] (mutex_lock_nested+0x28/0x4a8) [ 24.146908] [<c06023b0>] (mutex_lock_nested) from [<c03e9840>] (netcp_set_rx_mode+0x160/0x210) [ 24.155523] [<c03e9840>] (netcp_set_rx_mode) from [<c04c483c>] (dev_set_rx_mode+0x1c/0x28) [ 24.163787] [<c04c483c>] (dev_set_rx_mode) from [<c04c490c>] (__dev_open+0xc4/0x10c) [ 24.171531] [<c04c490c>] (__dev_open) from [<c04c4b74>] (__dev_change_flags+0x94/0x144) [ 24.179528] [<c04c4b74>] (__dev_change_flags) from [<c04c4c3c>] (dev_change_flags+0x18/0x48) [ 24.187966] [<c04c4c3c>] (dev_change_flags) from [<c053a9fc>] (devinet_ioctl+0x6dc/0x7e4) [ 24.196145] [<c053a9fc>] (devinet_ioctl) from [<c04a59ec>] (sock_ioctl+0x1d0/0x2a8) [ 24.203803] [<c04a59ec>] (sock_ioctl) from [<c0142844>] (do_vfs_ioctl+0x41c/0x688) [ 24.211373] [<c0142844>] (do_vfs_ioctl) from [<c0142ae4>] (SyS_ioctl+0x34/0x5c) [ 24.218676] [<c0142ae4>] (SyS_ioctl) from [<c000ff60>] (ret_fast_syscall+0x0/0x54) [ 24.227156] IPv6: ADDRCONF(NETDEV_UP): eth1: link is not ready Signed-off-by: Murali Karicheri <m-karicheri2@ti.com> Signed-off-by: David S. Miller <davem@davemloft.net>

Jonathan Liu reports that the recent addition of CPU_SW_DOMAIN_PAN causes wpa_supplicant to die due to the following kernel oops: Unhandled fault: page domain fault (0x81b) at 0x001017a2 pgd = ee1b8000 [001017a2] *pgd=6ebee831, *pte=6c35475f, *ppte=6c354c7f Internal error: : 81b [#1] SMP ARM Modules linked in: rt2800usb rt2x00usb rt2800librt2x00lib crc_ccitt mac80211 CPU: 1 PID: 202 Comm: wpa_supplicant Not tainted 4.3.0-rc2 #1 Hardware name: Allwinner sun7i (A20) Family task: ec872f80 ti: ee364000 task.ti: ee364000 PC is at do_alignment_ldmstm+0x1d4/0x238 LR is at 0x0 pc : [<c001d1d8>] lr : [<00000000>] psr: 600c0113 sp : ee365e18 ip : 00000000 fp : 00000002 r10: 001017a2 r9 : 00000002 r8 : 001017aa r7 : ee365fb0 r6 : e8820018 r5 : 001017a2 r4 : 00000003 r3 : d49e30e0 r2 : 00000000 r1 : ee365fbc r0 : 00000000 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none[ 34.393106] Control: 10c5387d Table: 6e1b806a DAC: 00000051 Process wpa_supplicant (pid: 202, stack limit = 0xee364210) Stack: (0xee365e18 to 0xee366000) ... [<c001d1d8>] (do_alignment_ldmstm) from [<c001d510>] (do_alignment+0x1f0/0x904) [<c001d510>] (do_alignment) from [<c00092a0>] (do_DataAbort+0x38/0xb4) [<c00092a0>] (do_DataAbort) from [<c0013d7c>] (__dabt_usr+0x3c/0x40) Exception stack(0xee365fb0 to 0xee365ff8) 5fa0: 00000000 56c728c0 001017a2 d49e30e0 5fc0: 775448d2 597d4e74 00200800 7a9e1625 00802001 00000021 b6deec84 00000100 5fe0: 08020200 be9f4f20 0c0b0d0a b6d9b3e0 600c0010 ffffffff Code: e1a0a005 e1a0000c 1affffe8 e5913000 (e4ea3001) ---[ end trace 0acd3882fcfdf9dd ]--- This is caused by the alignment handler not being fixed up for the uaccess changes, and userspace issuing an unaligned LDM instruction. So, fix the problem by adding the necessary fixups. Reported-by: Jonathan Liu <net147@gmail.com> Tested-by: Jonathan Liu <net147@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

kvm_set_cr0 may want to call kvm_zap_gfn_range and thus access the memslots array (SRCU protected). Using a mini SRCU critical section is ugly, and adding it to kvm_arch_vcpu_create doesn't work because the VMX vcpu_create callback calls synchronize_srcu. Fixes this lockdep splat: =============================== [ INFO: suspicious RCU usage. ] 4.3.0-rc1+ #1 Not tainted ------------------------------- include/linux/kvm_host.h:488 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 1 lock held by qemu-system-i38/17000: #0: (&(&kvm->mmu_lock)->rlock){+.+...}, at: kvm_zap_gfn_range+0x24/0x1a0 [kvm] [...] Call Trace: dump_stack+0x4e/0x84 lockdep_rcu_suspicious+0xfd/0x130 kvm_zap_gfn_range+0x188/0x1a0 [kvm] kvm_set_cr0+0xde/0x1e0 [kvm] init_vmcb+0x760/0xad0 [kvm_amd] svm_create_vcpu+0x197/0x250 [kvm_amd] kvm_arch_vcpu_create+0x47/0x70 [kvm] kvm_vm_ioctl+0x302/0x7e0 [kvm] ? __lock_is_held+0x51/0x70 ? __fget+0x101/0x210 do_vfs_ioctl+0x2f4/0x560 ? __fget_light+0x29/0x90 SyS_ioctl+0x4c/0x90 entry_SYSCALL_64_fastpath+0x16/0x73 Reported-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

ppp_dev_uninit() locks all_ppp_mutex while under rtnl mutex protection. ppp_create_interface() must then lock these mutexes in that same order to avoid possible deadlock. [ 120.880011] ====================================================== [ 120.880011] [ INFO: possible circular locking dependency detected ] [ 120.880011] 4.2.0 #1 Not tainted [ 120.880011] ------------------------------------------------------- [ 120.880011] ppp-apitest/15827 is trying to acquire lock: [ 120.880011] (&pn->all_ppp_mutex){+.+.+.}, at: [<ffffffffa0145f56>] ppp_dev_uninit+0x64/0xb0 [ppp_generic] [ 120.880011] [ 120.880011] but task is already holding lock: [ 120.880011] (rtnl_mutex){+.+.+.}, at: [<ffffffff812e4255>] rtnl_lock+0x12/0x14 [ 120.880011] [ 120.880011] which lock already depends on the new lock. [ 120.880011] [ 120.880011] [ 120.880011] the existing dependency chain (in reverse order) is: [ 120.880011] [ 120.880011] -> #1 (rtnl_mutex){+.+.+.}: [ 120.880011] [<ffffffff81073a6f>] lock_acquire+0xcf/0x10e [ 120.880011] [<ffffffff813ab18a>] mutex_lock_nested+0x56/0x341 [ 120.880011] [<ffffffff812e4255>] rtnl_lock+0x12/0x14 [ 120.880011] [<ffffffff812d9d94>] register_netdev+0x11/0x27 [ 120.880011] [<ffffffffa0147b17>] ppp_ioctl+0x289/0xc98 [ppp_generic] [ 120.880011] [<ffffffff8113b367>] do_vfs_ioctl+0x4ea/0x532 [ 120.880011] [<ffffffff8113b3fd>] SyS_ioctl+0x4e/0x7d [ 120.880011] [<ffffffff813ad7d7>] entry_SYSCALL_64_fastpath+0x12/0x6f [ 120.880011] [ 120.880011] -> #0 (&pn->all_ppp_mutex){+.+.+.}: [ 120.880011] [<ffffffff8107334e>] __lock_acquire+0xb07/0xe76 [ 120.880011] [<ffffffff81073a6f>] lock_acquire+0xcf/0x10e [ 120.880011] [<ffffffff813ab18a>] mutex_lock_nested+0x56/0x341 [ 120.880011] [<ffffffffa0145f56>] ppp_dev_uninit+0x64/0xb0 [ppp_generic] [ 120.880011] [<ffffffff812d5263>] rollback_registered_many+0x19e/0x252 [ 120.880011] [<ffffffff812d5381>] rollback_registered+0x29/0x38 [ 120.880011] [<ffffffff812d53fa>] unregister_netdevice_queue+0x6a/0x77 [ 120.880011] [<ffffffffa0146a94>] ppp_release+0x42/0x79 [ppp_generic] [ 120.880011] [<ffffffff8112d9f6>] __fput+0xec/0x192 [ 120.880011] [<ffffffff8112dacc>] ____fput+0x9/0xb [ 120.880011] [<ffffffff8105447a>] task_work_run+0x66/0x80 [ 120.880011] [<ffffffff81001801>] prepare_exit_to_usermode+0x8c/0xa7 [ 120.880011] [<ffffffff81001900>] syscall_return_slowpath+0xe4/0x104 [ 120.880011] [<ffffffff813ad931>] int_ret_from_sys_call+0x25/0x9f [ 120.880011] [ 120.880011] other info that might help us debug this: [ 120.880011] [ 120.880011] Possible unsafe locking scenario: [ 120.880011] [ 120.880011] CPU0 CPU1 [ 120.880011] ---- ---- [ 120.880011] lock(rtnl_mutex); [ 120.880011] lock(&pn->all_ppp_mutex); [ 120.880011] lock(rtnl_mutex); [ 120.880011] lock(&pn->all_ppp_mutex); [ 120.880011] [ 120.880011] *** DEADLOCK *** Fixes: 8cb775b ("ppp: fix device unregistration upon netns deletion") Reported-by: Sedat Dilek <sedat.dilek@gmail.com> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>

Andrey reported a panic: [ 7249.865507] BUG: unable to handle kernel pointer dereference at 000000b4 [ 7249.865559] IP: [<c16afeca>] icmp_route_lookup+0xaa/0x320 [ 7249.865598] *pdpt = 0000000030f7f001 *pde = 0000000000000000 [ 7249.865637] Oops: 0000 [#1] ... [ 7249.866811] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.3.0-999-generic #201509220155 [ 7249.866876] Hardware name: MSI MS-7250/MS-7250, BIOS 080014 08/02/2006 [ 7249.866916] task: c1a5ab00 ti: c1a52000 task.ti: c1a52000 [ 7249.866949] EIP: 0060:[<c16afeca>] EFLAGS: 00210246 CPU: 0 [ 7249.866981] EIP is at icmp_route_lookup+0xaa/0x320 [ 7249.867012] EAX: 00000000 EBX: f483ba48 ECX: 00000000 EDX: f2e18a00 [ 7249.867045] ESI: 000000c0 EDI: f483ba70 EBP: f483b9ec ESP: f483b974 [ 7249.867077] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 [ 7249.867108] CR0: 8005003b CR2: 000000b4 CR3: 36ee07c0 CR4: 000006f0 [ 7249.867141] Stack: [ 7249.867165] 320310ee 00000000 00000042 320310ee 00000000 c1aeca00 f3920240 f0c69180 [ 7249.867268] f483ba04 f855058b a89b66cd f483ba44 f8962f4b 00000000 e659266c f483ba54 [ 7249.867361] 8004753c f483ba5c f8962f4b f2031140 000003c1 ffbd8fa0 c16b0e00 00000064 [ 7249.867448] Call Trace: [ 7249.867494] [<f855058b>] ? e1000_xmit_frame+0x87b/0xdc0 [e1000e] [ 7249.867534] [<f8962f4b>] ? tcp_in_window+0xeb/0xb10 [nf_conntrack] [ 7249.867576] [<f8962f4b>] ? tcp_in_window+0xeb/0xb10 [nf_conntrack] [ 7249.867615] [<c16b0e00>] ? icmp_send+0xa0/0x380 [ 7249.867648] [<c16b102f>] icmp_send+0x2cf/0x380 [ 7249.867681] [<f89c8126>] nf_send_unreach+0xa6/0xc0 [nf_reject_ipv4] [ 7249.867714] [<f89cd0da>] reject_tg+0x7a/0x9f [ipt_REJECT] [ 7249.867746] [<f88c29a7>] ipt_do_table+0x317/0x70c [ip_tables] [ 7249.867780] [<f895e0a6>] ? __nf_conntrack_find_get+0x166/0x3b0 [nf_conntrack] [ 7249.867838] [<f895eea8>] ? nf_conntrack_in+0x398/0x600 [nf_conntrack] [ 7249.867889] [<f84c0035>] iptable_filter_hook+0x35/0x80 [iptable_filter] [ 7249.867933] [<c16776a1>] nf_iterate+0x71/0x80 [ 7249.867970] [<c1677715>] nf_hook_slow+0x65/0xc0 [ 7249.868002] [<c1681811>] __ip_local_out_sk+0xc1/0xd0 [ 7249.868034] [<c1680f30>] ? ip_forward_options+0x1a0/0x1a0 [ 7249.868066] [<c1681836>] ip_local_out_sk+0x16/0x30 [ 7249.868097] [<c1684054>] ip_send_skb+0x14/0x80 [ 7249.868129] [<c16840f4>] ip_push_pending_frames+0x34/0x40 [ 7249.868163] [<c16844a2>] ip_send_unicast_reply+0x282/0x310 [ 7249.868196] [<c16a0863>] tcp_v4_send_reset+0x1b3/0x380 [ 7249.868227] [<c16a1b63>] tcp_v4_rcv+0x323/0x990 [ 7249.868257] [<c16776a1>] ? nf_iterate+0x71/0x80 [ 7249.868289] [<c167dc2b>] ip_local_deliver_finish+0x8b/0x230 [ 7249.868322] [<c167df4c>] ip_local_deliver+0x4c/0xa0 [ 7249.868353] [<c167dba0>] ? ip_rcv_finish+0x390/0x390 [ 7249.868384] [<c167d88c>] ip_rcv_finish+0x7c/0x390 [ 7249.868415] [<c167e280>] ip_rcv+0x2e0/0x420 ... Prior to the VRF change the oif was not set in the flow struct, so the VRF support should really have only added the vrf_master_ifindex lookup. Fixes: 613d09b ("net: Use VRF device index for lookups on TX") Cc: Andrey Melnikov <temnota.am@gmail.com> Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>

Commit b6d3096 (Input: uinput - switch to using for_each_set_bit()) switched driver to use for_each_set_bit(). However during initial write of the uinput structure that contains min/max data for all possible axes none of them are reflected in dev->absbit yet and so we were skipping over all of them and were not allocating absinfo memory which caused crash later when driver tried to sens EV_ABS events: <1>[ 15.064330] BUG: unable to handle kernel NULL pointer dereference at 0000000000000024 <1>[ 15.064336] IP: [<ffffffff8163f142>] input_handle_event+0x232/0x4e0 <4>[ 15.064343] PGD 0 <4>[ 15.064345] Oops: 0000 [#1] SMP Fixes: b6d3096 Cc: stable@vger.kernel.org Reported-by: Stephen Chandler Paul <cpaul@redhat.com> Tested-by: Stephen Chandler Paul <cpaul@redhat.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

…t initialized. In case something goes wrong with power well initialization we were calling intel_prepare_ddi during boot while encoder list isnt't initilized. [ 9.618747] i915 0000:00:02.0: Invalid ROM contents [ 9.631446] [drm] failed to find VBIOS tables [ 9.720036] BUG: unable to handle kernel NULL pointer dereference at 00000000 00000058 [ 9.721986] IP: [<ffffffffa014eb72>] ddi_get_encoder_port+0x82/0x190 [i915] [ 9.723736] PGD 0 [ 9.724286] Oops: 0000 [#1] PREEMPT SMP [ 9.725386] Modules linked in: intel_powerclamp snd_hda_intel(+) coretemp crc 32c_intel snd_hda_codec snd_hda_core serio_raw snd_pcm snd_timer i915(+) parport _pc parport pinctrl_sunrisepoint pinctrl_intel nfsd nfs_acl [ 9.730635] CPU: 0 PID: 497 Comm: systemd-udevd Not tainted 4.3.0-rc2-eywa-10 967-g72de2cfd-dirty #2 [ 9.732785] Hardware name: Intel Corporation Cannonlake Client platform/Skyla ke DT DDR4 RVP8, BIOS CNLSE2R1.R00.X021.B00.1508040310 08/04/2015 [ 9.735785] task: ffff88008a704700 ti: ffff88016a1ac000 task.ti: ffff88016a1a c000 [ 9.737584] RIP: 0010:[<ffffffffa014eb72>] [<ffffffffa014eb72>] ddi_get_enco der_port+0x82/0x190 [i915] [ 9.739934] RSP: 0000:ffff88016a1af710 EFLAGS: 00010296 [ 9.741184] RAX: 000000000000004e RBX: ffff88008a9edc98 RCX: 0000000000000001 [ 9.742934] RDX: 000000000000004e RSI: ffffffff81fc1e82 RDI: 00000000ffffffff [ 9.744634] RBP: ffff88016a1af730 R08: 0000000000000000 R09: 0000000000000578 [ 9.746333] R10: 0000000000001065 R11: 0000000000000578 R12: fffffffffffffff8 [ 9.748033] R13: ffff88016a1af7a8 R14: ffff88016a1af794 R15: 0000000000000000 [ 9.749733] FS: 00007eff2e1e07c0(0000) GS:ffff88016fc00000(0000) knlGS:00000 00000000000 [ 9.751683] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 9.753083] CR2: 0000000000000058 CR3: 000000016922b000 CR4: 00000000003406f0 [ 9.754782] Stack: [ 9.755332] ffff88008a9edc98 ffff88008a9ed800 ffffffffa01d07b0 00000000fffb9 09e [ 9.757232] ffff88016a1af7d8 ffffffffa0154ea7 0000000000000246 ffff88016a370 080 [ 9.759182] ffff88016a370080 ffff88008a9ed800 0000000000000246 ffff88008a9ed c98 [ 9.761132] Call Trace: [ 9.761782] [<ffffffffa0154ea7>] intel_prepare_ddi+0x67/0x860 [i915] [ 9.763332] [<ffffffff81a56996>] ? _raw_spin_unlock_irqrestore+0x26/0x40 [ 9.765031] [<ffffffffa00fad01>] ? gen9_read32+0x141/0x360 [i915] [ 9.766531] [<ffffffffa00b43e1>] skl_set_power_well+0x431/0xa80 [i915] [ 9.768181] [<ffffffffa00b4a63>] skl_power_well_enable+0x13/0x20 [i915] [ 9.769781] [<ffffffffa00b2188>] intel_power_well_enable+0x28/0x50 [i915] [ 9.771481] [<ffffffffa00b4d52>] intel_display_power_get+0x92/0xc0 [i915] [ 9.773180] [<ffffffffa00b4fcb>] intel_display_set_init_power+0x3b/0x40 [i91 5] [ 9.774980] [<ffffffffa00b5170>] intel_power_domains_init_hw+0x120/0x520 [i9 15] [ 9.776780] [<ffffffffa0194c61>] i915_driver_load+0xb21/0xf40 [i915] So let's protect this case. My first attempt was to remove the intel_prepare_ddi, but Daniel had pointed out this is really needed to restore those registers values. And Imre pointed out that this case was without the flag protection and this was actually where things were going bad. So I've just checked and this indeed solves my issue. The regressing intel_prepare_ddi call was added in commit 1d2b952 Author: Damien Lespiau <damien.lespiau@intel.com> Date: Fri Mar 6 18:50:53 2015 +0000 drm/i915/skl: Restore the DDI translation tables when enabling PW1 Cc: Imre Deak <imre.deak@intel.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> Reviewed-by: Imre Deak <imre.deak@intel.com> [Jani: regression reference] Signed-off-by: Jani Nikula <jani.nikula@intel.com>

…ut event A case can occur when sctp_accept() is called by the user during a heartbeat timeout event after the 4-way handshake. Since sctp_assoc_migrate() changes both assoc->base.sk and assoc->ep, the bh_sock_lock in sctp_generate_heartbeat_event() will be taken with the listening socket but released with the new association socket. The result is a deadlock on any future attempts to take the listening socket lock. Note that this race can occur with other SCTP timeouts that take the bh_lock_sock() in the event sctp_accept() is called. BUG: soft lockup - CPU#9 stuck for 67s! [swapper:0] ... RIP: 0010:[<ffffffff8152d48e>] [<ffffffff8152d48e>] _spin_lock+0x1e/0x30 RSP: 0018:ffff880028323b20 EFLAGS: 00000206 RAX: 0000000000000002 RBX: ffff880028323b20 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff880028323be0 RDI: ffff8804632c4b48 RBP: ffffffff8100bb93 R08: 0000000000000000 R09: 0000000000000000 R10: ffff880610662280 R11: 0000000000000100 R12: ffff880028323aa0 R13: ffff8804383c3880 R14: ffff880028323a90 R15: ffffffff81534225 FS: 0000000000000000(0000) GS:ffff880028320000(0000) knlGS:0000000000000000 CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b CR2: 00000000006df528 CR3: 0000000001a85000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process swapper (pid: 0, threadinfo ffff880616b70000, task ffff880616b6cab0) Stack: ffff880028323c40 ffffffffa01c2582 ffff880614cfb020 0000000000000000 <d> 0100000000000000 00000014383a6c44 ffff8804383c3880 ffff880614e93c00 <d> ffff880614e93c00 0000000000000000 ffff8804632c4b00 ffff8804383c38b8 Call Trace: <IRQ> [<ffffffffa01c2582>] ? sctp_rcv+0x492/0xa10 [sctp] [<ffffffff8148c559>] ? nf_iterate+0x69/0xb0 [<ffffffff814974a0>] ? ip_local_deliver_finish+0x0/0x2d0 [<ffffffff8148c716>] ? nf_hook_slow+0x76/0x120 [<ffffffff814974a0>] ? ip_local_deliver_finish+0x0/0x2d0 [<ffffffff8149757d>] ? ip_local_deliver_finish+0xdd/0x2d0 [<ffffffff81497808>] ? ip_local_deliver+0x98/0xa0 [<ffffffff81496ccd>] ? ip_rcv_finish+0x12d/0x440 [<ffffffff81497255>] ? ip_rcv+0x275/0x350 [<ffffffff8145cfeb>] ? __netif_receive_skb+0x4ab/0x750 ... With lockdep debugging: ===================================== [ BUG: bad unlock balance detected! ] ------------------------------------- CslRx/12087 is trying to release lock (slock-AF_INET) at: [<ffffffffa01bcae0>] sctp_generate_timeout_event+0x40/0xe0 [sctp] but there are no more locks to release! other info that might help us debug this: 2 locks held by CslRx/12087: #0: (&asoc->timers[i]){+.-...}, at: [<ffffffff8108ce1f>] run_timer_softirq+0x16f/0x3e0 #1: (slock-AF_INET){+.-...}, at: [<ffffffffa01bcac3>] sctp_generate_timeout_event+0x23/0xe0 [sctp] Ensure the socket taken is also the same one that is released by saving a copy of the socket before entering the timeout event critical section. Signed-off-by: Karl Heiss <kheiss@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>

Fixes the following lockdep splat: [ 1.244527] ============================================= [ 1.245193] [ INFO: possible recursive locking detected ] [ 1.245193] 4.2.0-rc1+ torvalds#37 Not tainted [ 1.245193] --------------------------------------------- [ 1.245193] cp/742 is trying to acquire lock: [ 1.245193] (&sb->s_type->i_mutex_key#9){+.+.+.}, at: [<ffffffff812b3f69>] ubifs_init_security+0x29/0xb0 [ 1.245193] [ 1.245193] but task is already holding lock: [ 1.245193] (&sb->s_type->i_mutex_key#9){+.+.+.}, at: [<ffffffff81198e7f>] path_openat+0x3af/0x1280 [ 1.245193] [ 1.245193] other info that might help us debug this: [ 1.245193] Possible unsafe locking scenario: [ 1.245193] [ 1.245193] CPU0 [ 1.245193] ---- [ 1.245193] lock(&sb->s_type->i_mutex_key#9); [ 1.245193] lock(&sb->s_type->i_mutex_key#9); [ 1.245193] [ 1.245193] *** DEADLOCK *** [ 1.245193] [ 1.245193] May be due to missing lock nesting notation [ 1.245193] [ 1.245193] 2 locks held by cp/742: [ 1.245193] #0: (sb_writers#5){.+.+.+}, at: [<ffffffff811ad37f>] mnt_want_write+0x1f/0x50 [ 1.245193] #1: (&sb->s_type->i_mutex_key#9){+.+.+.}, at: [<ffffffff81198e7f>] path_openat+0x3af/0x1280 [ 1.245193] [ 1.245193] stack backtrace: [ 1.245193] CPU: 2 PID: 742 Comm: cp Not tainted 4.2.0-rc1+ torvalds#37 [ 1.245193] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140816_022509-build35 04/01/2014 [ 1.245193] ffffffff8252d530 ffff88007b023a38 ffffffff814f6f49 ffffffff810b56c5 [ 1.245193] ffff88007c30cc80 ffff88007b023af8 ffffffff810a150d ffff88007b023a68 [ 1.245193] 000000008101302a ffff880000000000 00000008f447e23f ffffffff8252d500 [ 1.245193] Call Trace: [ 1.245193] [<ffffffff814f6f49>] dump_stack+0x4c/0x65 [ 1.245193] [<ffffffff810b56c5>] ? console_unlock+0x1c5/0x510 [ 1.245193] [<ffffffff810a150d>] __lock_acquire+0x1a6d/0x1ea0 [ 1.245193] [<ffffffff8109fa78>] ? __lock_is_held+0x58/0x80 [ 1.245193] [<ffffffff810a1a93>] lock_acquire+0xd3/0x270 [ 1.245193] [<ffffffff812b3f69>] ? ubifs_init_security+0x29/0xb0 [ 1.245193] [<ffffffff814fc83b>] mutex_lock_nested+0x6b/0x3a0 [ 1.245193] [<ffffffff812b3f69>] ? ubifs_init_security+0x29/0xb0 [ 1.245193] [<ffffffff812b3f69>] ? ubifs_init_security+0x29/0xb0 [ 1.245193] [<ffffffff812b3f69>] ubifs_init_security+0x29/0xb0 [ 1.245193] [<ffffffff8128e286>] ubifs_create+0xa6/0x1f0 [ 1.245193] [<ffffffff81198e7f>] ? path_openat+0x3af/0x1280 [ 1.245193] [<ffffffff81195d15>] vfs_create+0x95/0xc0 [ 1.245193] [<ffffffff8119929c>] path_openat+0x7cc/0x1280 [ 1.245193] [<ffffffff8109ffe3>] ? __lock_acquire+0x543/0x1ea0 [ 1.245193] [<ffffffff81088f20>] ? sched_clock_cpu+0x90/0xc0 [ 1.245193] [<ffffffff81088c00>] ? calc_global_load_tick+0x60/0x90 [ 1.245193] [<ffffffff81088f20>] ? sched_clock_cpu+0x90/0xc0 [ 1.245193] [<ffffffff811a9cef>] ? __alloc_fd+0xaf/0x180 [ 1.245193] [<ffffffff8119ac55>] do_filp_open+0x75/0xd0 [ 1.245193] [<ffffffff814ffd86>] ? _raw_spin_unlock+0x26/0x40 [ 1.245193] [<ffffffff811a9cef>] ? __alloc_fd+0xaf/0x180 [ 1.245193] [<ffffffff81189bd9>] do_sys_open+0x129/0x200 [ 1.245193] [<ffffffff81189cc9>] SyS_open+0x19/0x20 [ 1.245193] [<ffffffff81500717>] entry_SYSCALL_64_fastpath+0x12/0x6f While the lockdep splat is a false positive, becuase path_openat holds i_mutex of the parent directory and ubifs_init_security() tries to acquire i_mutex of a new inode, it reveals that taking i_mutex in ubifs_init_security() is in vain because it is only being called in the inode allocation path and therefore nobody else can see the inode yet. Cc: stable@vger.kernel.org # 3.20- Reported-and-tested-by: Boris Brezillon <boris.brezillon@free-electrons.com> Reviewed-and-tested-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com> Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: dedekind1@gmail.com

Dmitry Vyukov reported the following using trinity and the memory error detector AddressSanitizer (https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel). [ 124.575597] ERROR: AddressSanitizer: heap-buffer-overflow on address ffff88002e280000 [ 124.576801] ffff88002e280000 is located 131938492886538 bytes to the left of 28857600-byte region [ffffffff81282e0a, ffffffff82e0830a) [ 124.578633] Accessed by thread T10915: [ 124.579295] inlined in describe_heap_address ./arch/x86/mm/asan/report.c:164 [ 124.579295] #0 ffffffff810dd277 in asan_report_error ./arch/x86/mm/asan/report.c:278 [ 124.580137] #1 ffffffff810dc6a0 in asan_check_region ./arch/x86/mm/asan/asan.c:37 [ 124.581050] #2 ffffffff810dd423 in __tsan_read8 ??:0 [ 124.581893] #3 ffffffff8107c093 in get_wchan ./arch/x86/kernel/process_64.c:444 The address checks in the 64bit implementation of get_wchan() are wrong in several ways: - The lower bound of the stack is not the start of the stack page. It's the start of the stack page plus sizeof (struct thread_info) - The upper bound must be: top_of_stack - TOP_OF_KERNEL_STACK_PADDING - 2 * sizeof(unsigned long). The 2 * sizeof(unsigned long) is required because the stack pointer points at the frame pointer. The layout on the stack is: ... IP FP ... IP FP. So we need to make sure that both IP and FP are in the bounds. Fix the bound checks and get rid of the mix of numeric constants, u64 and unsigned long. Making all unsigned long allows us to use the same function for 32bit as well. Use READ_ONCE() when accessing the stack. This does not prevent a concurrent wakeup of the task and the stack changing, but at least it avoids TOCTOU. Also check task state at the end of the loop. Again that does not prevent concurrent changes, but it avoids walking for nothing. Add proper comments while at it. Reported-by: Dmitry Vyukov <dvyukov@google.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Based-on-patch-from: Wolfram Gloger <wmglo@dent.med.uni-muenchen.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@alien8.de> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: kasan-dev <kasan-dev@googlegroups.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Wolfram Gloger <wmglo@dent.med.uni-muenchen.de> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20150930083302.694788319@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

…fy a fault SunDong reported the following on https://bugzilla.kernel.org/show_bug.cgi?id=103841 I think I find a linux bug, I have the test cases is constructed. I can stable recurring problems in fedora22(4.0.4) kernel version, arch for x86_64. I construct transparent huge page, when the parent and child process with MAP_SHARE, MAP_PRIVATE way to access the same huge page area, it has the opportunity to lead to huge page copy on write failure, and then it will munmap the child corresponding mmap area, but then the child mmap area with VM_MAYSHARE attributes, child process munmap this area can trigger VM_BUG_ON in set_vma_resv_flags functions (vma - > vm_flags & VM_MAYSHARE). There were a number of problems with the report (e.g. it's hugetlbfs that triggers this, not transparent huge pages) but it was fundamentally correct in that a VM_BUG_ON in set_vma_resv_flags() can be triggered that looks like this vma ffff8804651fd0d0 start 00007fc474e00000 end 00007fc475e00000 next ffff8804651fd018 prev ffff8804651fd188 mm ffff88046b1b1800 prot 8000000000000027 anon_vma (null) vm_ops ffffffff8182a7a0 pgoff 0 file ffff88106bdb9800 private_data (null) flags: 0x84400fb(read|write|shared|mayread|maywrite|mayexec|mayshare|dontexpand|hugetlb) ------------ kernel BUG at mm/hugetlb.c:462! SMP Modules linked in: xt_pkttype xt_LOG xt_limit [..] CPU: 38 PID: 26839 Comm: map Not tainted 4.0.4-default #1 Hardware name: Dell Inc. PowerEdge R810/0TT6JF, BIOS 2.7.4 04/26/2012 set_vma_resv_flags+0x2d/0x30 The VM_BUG_ON is correct because private and shared mappings have different reservation accounting but the warning clearly shows that the VMA is shared. When a private COW fails to allocate a new page then only the process that created the VMA gets the page -- all the children unmap the page. If the children access that data in the future then they get killed. The problem is that the same file is mapped shared and private. During the COW, the allocation fails, the VMAs are traversed to unmap the other private pages but a shared VMA is found and the bug is triggered. This patch identifies such VMAs and skips them. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Reported-by: SunDong <sund_sky@126.com> Reviewed-by: Michal Hocko <mhocko@suse.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: David Rientjes <rientjes@google.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Since 9eb1e57 drm/dp/mst: make sure mst_primary mstb is valid in work function we validate the mstb structs in the work function, and doing that takes a reference. So we should never get here with the work function running using the mstb device, only if the work function hasn't run yet or is running for another mstb. So we don't need to sync the work here, this was causing lockdep spew as below. [ +0.000160] ============================================= [ +0.000001] [ INFO: possible recursive locking detected ] [ +0.000002] 3.10.0-320.el7.rhel72.stable.backport.3.x86_64.debug #1 Tainted: G W ------------ [ +0.000001] --------------------------------------------- [ +0.000001] kworker/4:2/1262 is trying to acquire lock: [ +0.000001] ((&mgr->work)){+.+.+.}, at: [<ffffffff810b29a5>] flush_work+0x5/0x2e0 [ +0.000007] but task is already holding lock: [ +0.000001] ((&mgr->work)){+.+.+.}, at: [<ffffffff810b57e4>] process_one_work+0x1b4/0x710 [ +0.000004] other info that might help us debug this: [ +0.000001] Possible unsafe locking scenario: [ +0.000002] CPU0 [ +0.000000] ---- [ +0.000001] lock((&mgr->work)); [ +0.000002] lock((&mgr->work)); [ +0.000001] *** DEADLOCK *** [ +0.000001] May be due to missing lock nesting notation [ +0.000002] 2 locks held by kworker/4:2/1262: [ +0.000001] #0: (events_long){.+.+.+}, at: [<ffffffff810b57e4>] process_one_work+0x1b4/0x710 [ +0.000004] #1: ((&mgr->work)){+.+.+.}, at: [<ffffffff810b57e4>] process_one_work+0x1b4/0x710 [ +0.000003] stack backtrace: [ +0.000003] CPU: 4 PID: 1262 Comm: kworker/4:2 Tainted: G W ------------ 3.10.0-320.el7.rhel72.stable.backport.3.x86_64.debug #1 [ +0.000001] Hardware name: LENOVO 20EGS0R600/20EGS0R600, BIOS GNET71WW (2.19 ) 02/05/2015 [ +0.000008] Workqueue: events_long drm_dp_mst_link_probe_work [drm_kms_helper] [ +0.000001] ffffffff82c26c90 00000000a527b914 ffff88046399bae8 ffffffff816fe04d [ +0.000004] ffff88046399bb58 ffffffff8110f47f ffff880461438000 0001009b840fc003 [ +0.000002] ffff880461438a98 0000000000000000 0000000804dc26e1 ffffffff824a2c00 [ +0.000003] Call Trace: [ +0.000004] [<ffffffff816fe04d>] dump_stack+0x19/0x1b [ +0.000004] [<ffffffff8110f47f>] __lock_acquire+0x115f/0x1250 [ +0.000002] [<ffffffff8110fd49>] lock_acquire+0x99/0x1e0 [ +0.000002] [<ffffffff810b29a5>] ? flush_work+0x5/0x2e0 [ +0.000002] [<ffffffff810b29ee>] flush_work+0x4e/0x2e0 [ +0.000002] [<ffffffff810b29a5>] ? flush_work+0x5/0x2e0 [ +0.000004] [<ffffffff81025905>] ? native_sched_clock+0x35/0x80 [ +0.000002] [<ffffffff81025959>] ? sched_clock+0x9/0x10 [ +0.000002] [<ffffffff810da1f5>] ? local_clock+0x25/0x30 [ +0.000002] [<ffffffff8110dca9>] ? mark_held_locks+0xb9/0x140 [ +0.000003] [<ffffffff810b4ed5>] ? __cancel_work_timer+0x95/0x160 [ +0.000002] [<ffffffff810b4ee8>] __cancel_work_timer+0xa8/0x160 [ +0.000002] [<ffffffff810b4fb0>] cancel_work_sync+0x10/0x20 [ +0.000007] [<ffffffffa0160d17>] drm_dp_destroy_mst_branch_device+0x27/0x120 [drm_kms_helper] [ +0.000006] [<ffffffffa0163968>] drm_dp_mst_link_probe_work+0x78/0xa0 [drm_kms_helper] [ +0.000002] [<ffffffff810b5850>] process_one_work+0x220/0x710 [ +0.000002] [<ffffffff810b57e4>] ? process_one_work+0x1b4/0x710 [ +0.000005] [<ffffffff810b5e5b>] worker_thread+0x11b/0x3a0 [ +0.000003] [<ffffffff810b5d40>] ? process_one_work+0x710/0x710 [ +0.000002] [<ffffffff810beced>] kthread+0xed/0x100 [ +0.000003] [<ffffffff810bec00>] ? insert_kthread_work+0x80/0x80 [ +0.000003] [<ffffffff817121d8>] ret_from_fork+0x58/0x90 v2: add flush_work. Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: stable@vger.kernel.org Signed-off-by: Dave Airlie <airlied@redhat.com>

When function graph tracer is enabled, the following operation will trigger panic: mount -t debugfs nodev /sys/kernel echo next_tgid > /sys/kernel/tracing/set_ftrace_filter echo function_graph > /sys/kernel/tracing/current_tracer ls /proc/ ------------[ cut here ]------------ [ 198.501417] Unable to handle kernel paging request at virtual address cb88537fdc8ba316 [ 198.506126] pgd = ffffffc008f79000 [ 198.509363] [cb88537fdc8ba316] *pgd=00000000488c6003, *pud=00000000488c6003, *pmd=0000000000000000 [ 198.517726] Internal error: Oops: 94000005 [#1] SMP [ 198.518798] Modules linked in: [ 198.520582] CPU: 1 PID: 1388 Comm: ls Tainted: G [ 198.521800] Hardware name: linux,dummy-virt (DT) [ 198.522852] task: ffffffc0fa9e8000 ti: ffffffc0f9ab0000 task.ti: ffffffc0f9ab0000 [ 198.524306] PC is at next_tgid+0x30/0x100 [ 198.525205] LR is at return_to_handler+0x0/0x20 [ 198.526090] pc : [<ffffffc0002a1070>] lr : [<ffffffc0000907c0>] pstate: 60000145 [ 198.527392] sp : ffffffc0f9ab3d40 [ 198.528084] x29: ffffffc0f9ab3d40 x28: ffffffc0f9ab0000 [ 198.529406] x27: ffffffc000d6a000 x26: ffffffc000b786e8 [ 198.530659] x25: ffffffc0002a1900 x24: ffffffc0faf16c00 [ 198.531942] x23: ffffffc0f9ab3ea0 x22: 0000000000000002 [ 198.533202] x21: ffffffc000d85050 x20: 0000000000000002 [ 198.534446] x19: 0000000000000002 x18: 0000000000000000 [ 198.535719] x17: 000000000049fa08 x16: ffffffc000242efc [ 198.537030] x15: 0000007fa472b54c x14: ffffffffff000000 [ 198.538347] x13: ffffffc0fada84a0 x12: 0000000000000001 [ 198.539634] x11: ffffffc0f9ab3d70 x10: ffffffc0f9ab3d70 [ 198.540915] x9 : ffffffc0000907c0 x8 : ffffffc0f9ab3d40 [ 198.542215] x7 : 0000002e330f08f0 x6 : 0000000000000015 [ 198.543508] x5 : 0000000000000f08 x4 : ffffffc0f9835ec0 [ 198.544792] x3 : cb88537fdc8ba316 x2 : cb88537fdc8ba306 [ 198.546108] x1 : 0000000000000002 x0 : ffffffc000d85050 [ 198.547432] [ 198.547920] Process ls (pid: 1388, stack limit = 0xffffffc0f9ab0020) [ 198.549170] Stack: (0xffffffc0f9ab3d40 to 0xffffffc0f9ab4000) [ 198.582568] Call trace: [ 198.583313] [<ffffffc0002a1070>] next_tgid+0x30/0x100 [ 198.584359] [<ffffffc0000907bc>] ftrace_graph_caller+0x6c/0x70 [ 198.585503] [<ffffffc0000907bc>] ftrace_graph_caller+0x6c/0x70 [ 198.586574] [<ffffffc0000907bc>] ftrace_graph_caller+0x6c/0x70 [ 198.587660] [<ffffffc0000907bc>] ftrace_graph_caller+0x6c/0x70 [ 198.588896] Code: aa0003f5 2a0103f4 b4000102 91004043 (885f7c60) [ 198.591092] ---[ end trace 6a346f8f20949ac8 ]--- This is because when using function graph tracer, if the traced function return value is in multi regs ([x0-x7]), return_to_handler may corrupt them. So in return_to_handler, the parameter regs should be protected properly. Cc: <stable@vger.kernel.org> # 3.18+ Signed-off-by: Li Bin <huawei.libin@huawei.com> Acked-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Commit 1a3d595 ("MIPS: Tidy up FPU context switching") removed FP context saving from the asm-written resume function in favour of reusing existing code to perform the same task. However it only removed the FP context saving code from the r4k_switch.S implementation of resume. Octeon uses its own implementation in octeon_switch.S, so remove FP context saving there too in order to prevent attempting to save context twice. That formerly led to an exception from the second save as follows because the FPU had already been disabled by the first save: do_cpu invoked from kernel context![#1]: CPU: 0 PID: 2 Comm: kthreadd Not tainted 4.3.0-rc2-dirty #2 task: 800000041f84a008 ti: 800000041f864000 task.ti: 800000041f864000 $ 0 : 0000000000000000 0000000010008ce1 0000000000100000 ffffffffbfffffff $ 4 : 800000041f84a008 800000041f84ac08 800000041f84c000 0000000000000004 $ 8 : 0000000000000001 0000000000000000 0000000000000000 0000000000000001 $12 : 0000000010008ce3 0000000000119c60 0000000000000036 800000041f864000 $16 : 800000041f84ac08 800000000792ce80 800000041f84a008 ffffffff81758b00 $20 : 0000000000000000 ffffffff8175ae50 0000000000000000 ffffffff8176c740 $24 : 0000000000000006 ffffffff81170300 $28 : 800000041f864000 800000041f867d90 0000000000000000 ffffffff815f3fa0 Hi : 0000000000fa8257 Lo : ffffffffe15cfc00 epc : ffffffff8112821c resume+0x9c/0x200 ra : ffffffff815f3fa0 __schedule+0x3f0/0x7d8 Status: 10008ce2 KX SX UX KERNEL EXL Cause : 1080002c (ExcCode 0b) PrId : 000d0601 (Cavium Octeon+) Modules linked in: Process kthreadd (pid: 2, threadinfo=800000041f864000, task=800000041f84a008, tls=0000000000000000) Stack : ffffffff81604218 ffffffff815f7e08 800000041f84a008 ffffffff811681b0 800000041f84a008 ffffffff817e9878 0000000000000000 ffffffff81770000 ffffffff81768340 ffffffff81161398 0000000000000001 0000000000000000 0000000000000000 ffffffff815f4424 0000000000000000 ffffffff81161d68 ffffffff81161be8 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 ffffffff8111e16c 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 ... Call Trace: [<ffffffff8112821c>] resume+0x9c/0x200 [<ffffffff815f3fa0>] __schedule+0x3f0/0x7d8 [<ffffffff815f4424>] schedule+0x34/0x98 [<ffffffff81161d68>] kthreadd+0x180/0x198 [<ffffffff8111e16c>] ret_from_kernel_thread+0x14/0x1c Tested using cavium_octeon_defconfig on an EdgeRouter Lite. Fixes: 1a3d595 ("MIPS: Tidy up FPU context switching") Reported-by: Aaro Koskinen <aaro.koskinen@nokia.com> Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Aleksey Makarov <aleksey.makarov@auriga.com> Cc: linux-kernel@vger.kernel.org Cc: Chandrakala Chavva <cchavva@caviumnetworks.com> Cc: David Daney <david.daney@cavium.com> Cc: Leonid Rosenboim <lrosenboim@caviumnetworks.com> Patchwork: https://patchwork.linux-mips.org/patch/11166/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

it was broken by 35d5d20 "mtd: mxc_nand: cleanup copy_spare function" else we get the following error : [ 22.709507] ubi0: attaching mtd3 [ 23.613470] ubi0: scanning is finished [ 23.617278] ubi0: empty MTD device detected [ 23.623219] Unhandled fault: imprecise external abort (0x1c06) at 0x9e62f0ec [ 23.630291] pgd = 9df80000 [ 23.633005] [9e62f0ec] *pgd=8e60041e(bad) [ 23.637064] Internal error: : 1c06 [#1] SMP ARM [ 23.641605] Modules linked in: [ 23.644687] CPU: 0 PID: 99 Comm: ubiattach Not tainted 4.2.0-dirty torvalds#22 [ 23.651222] Hardware name: Freescale i.MX53 (Device Tree Support) [ 23.657322] task: 9e687300 ti: 9dcfc000 task.ti: 9dcfc000 [ 23.662744] PC is at memcpy16_toio+0x4c/0x74 [ 23.667026] LR is at mxc_nand_command+0x484/0x640 [ 23.671739] pc : [<803f9c08>] lr : [<803faeb0>] psr: 60000013 [ 23.671739] sp : 9dcfdb10 ip : 9e62f0ea fp : 9dcfdb1c [ 23.683222] r10: a09c1000 r9 : 0000001a r8 : ffffffff [ 23.688453] r7 : ffffffff r6 : 9e674810 r5 : 9e674810 r4 : 000000b6 [ 23.694985] r3 : a09c16a4 r2 : a09c16a4 r1 : a09c16a4 r0 : 0000ffff [ 23.701521] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user [ 23.708662] Control: 10c5387d Table: 8df80019 DAC: 00000015 [ 23.714413] Process ubiattach (pid: 99, stack limit = 0x9dcfc210) [ 23.720514] Stack: (0x9dcfdb10 to 0x9dcfe000) [ 23.724881] db00: 9dcfdb6c 9dcfdb20 803faeb0 803f9bc8 [ 23.733069] db20: 803f227c 803f9b74 ffffffff 9e674810 9e674810 9e674810 00000040 9e62f010 [ 23.741255] db40: 803faa2c 9e674b40 9e674810 803faa2c 00000400 803faa2c 00000000 9df42800 [ 23.749441] db60: 9dcfdb9c 9dcfdb70 803f2024 803faa38 9e4201cc 00000000 803f0a78 9e674b40 [ 23.757627] db80: 803f1f80 9e674810 00000400 00000400 9dcfdc14 9dcfdba0 803f3bd8 803f1f8c [ 23.765814] dba0: 9e4201cc 00000000 00000580 00000000 00000000 800718c0 0000007f 00001000 [ 23.774000] dbc0: 9df42800 000000e0 00000000 00000000 9e4201cc 00000000 00000000 00000000 [ 23.782186] dbe0: 00000580 00000580 00000000 9e674810 9dcfdc20 9dcfdce8 9df42800 00580000 [ 23.790372] dc00: 00000000 00000400 9dcfdc6c 9dcfdc18 803f3f94 803f39a4 9dcfdc20 00000000 [ 23.798558] dc20: 00000000 00000400 00000000 00000000 00000000 00000000 9df42800 00000000 [ 23.806744] dc40: 9dcfdd0c 00580000 00000000 00000400 00000000 9df42800 9dee1000 9d802000 [ 23.814930] dc60: 9dcfdc94 9dcfdc70 803eb63c 803f3f38 00000400 9dcfdce8 9df42800 dead4ead [ 23.823116] dc80: 803eb5f4 00000000 9dcfdcc4 9dcfdc98 803e82ac 803eb600 00000400 9dcfdce8 [ 23.831301] dca0: 9df42800 00000400 9dee0000 00000000 00000400 00000000 9dcfdd1c 9dcfdcc8 [ 23.839488] dcc0: 80406048 803e8230 00000400 9dcfdce8 9df42800 9dcfdc78 00000008 00000000 [ 23.847673] dce0: 00000000 00000000 00000000 00000004 00000000 9df42800 9dee0000 00000000 [ 23.855859] dd00: 9d802030 00000000 9dc8b214 9d802000 9dcfdd44 9dcfdd20 804066cc 80405f50 [ 23.864047] dd20: 00000400 9dc8b200 9d802030 9df42800 9dee0000 9dc8b200 9dcfdd84 9dcfdd48 [ 23.872233] dd40: 8040a544 804065ac 9e401c80 000080d0 9dcfdd84 00000001 800fc828 9df42400 [ 23.880418] dd60: 00000000 00000080 9dc8b200 9dc8b200 9dc8b200 9dee0000 9dcfdddc 9dcfdd8 [ 23.888605] dd80: 803fb560 8040a440 9dcfddc4 9dcfdd98 800f1428 9dee1000 a0acf000 00000000 [ 23.896792] dda0: 00000000 ffffffff 00000006 00000000 9dee0000 9dee0000 00005600 00000080 [ 23.904979] ddc0: 9dc8b200 a0acf000 9dc8b200 8112514c 9dcfde24 9dcfdde0 803fc08c 803fb4f0 [ 23.913165] dde0: 9e401c80 00000013 9dcfde04 9dcfddf8 8006bbf8 8006ba00 9dcfde24 00000000 [ 23.921351] de00: 9dee0000 00000065 9dee0000 00000001 9dc8b200 8112514c 9dcfde84 9dcfde28 [ 23.929538] de20: 8040afa0 803fb948 ffffffff 00000000 9dc8b214 9dcfde40 800f1428 800f11dc [ 23.937724] de40: 9dc8b21c 9dc8b20c 9dc8b204 9dee1000 9dc8b214 8069bb60 fffff000 fffff000 [ 23.945911] de60: 9e7b5400 00000000 9dee0000 9dee1000 00001000 9e7b5400 9dcfdecc 9dcfde88 [ 23.954097] de80: 803ff1bc 8040a630 9dcfdea4 9dcfde98 00000800 00000800 9dcfdecc 9dcfdea8 [ 23.962284] dea0: 803e8f6c 00000000 7e87ab70 9e7b5400 80113e30 00000003 9dcfc000 00000000 [ 23.970470] dec0: 9dcfdf04 9dcfded0 804008cc 803feb98 ffffffff 00000003 00000000 00000000 [ 23.978656] dee0: 00000000 00000000 9e7cb000 9dc193e0 7e87ab70 9dd92140 9dcfdf7c 9dcfdf08 [ 23.986842] df00: 80113b5c 8040080c 800fbed8 8006bbf0 9e7cb000 00000003 9e7cb000 9dd92140 [ 23.995029] df20: 9dc193e0 9dd92148 9dcfdf4c 9dcfdf38 8011022c 800fbe78 8000f9cc 9e687300 [ 24.003216] df40: 9dcfdf6c 9dcfdf50 8011f798 8007ffe8 7e87ab70 9dd92140 00000003 9dd92140 [ 24.011402] df60: 40186f40 7e87ab70 9dcfc000 00000000 9dcfdfa4 9dcfdf80 80113e30 8011373c [ 24.019588] df80: 7e87ab70 7e87ab70 7e87aea9 00000036 8000fb8 9dcfc000 00000000 9dcfdfa8 [ 24.027775] dfa0: 8000f9a0 80113e00 7e87ab70 7e87ab70 00000003 40186f40 7e87ab70 00000000 [ 24.035962] dfc0: 7e87ab70 7e87ab70 7e87aea9 00000036 00000000 00000000 76fd1f70 00000000 [ 24.044148] dfe0: 76f80f8c 7e87ab28 00009810 76f80fc4 60000010 00000003 00000000 00000000 [ 24.052328] Backtrace: [ 24.054806] [<803f9bbc>] (memcpy16_toio) from [<803faeb0>] (mxc_nand_command+0x484/0x640) [ 24.062996] [<803faa2c>] (mxc_nand_command) from [<803f2024>] (nand_write_page+0xa4/0x154) [ 24.071264] r10:9df42800 r9:00000000 r8:803faa2c r7:00000400 r6:803faa2c r5:9e674810 [ 24.079180] r4:9e674b40 [ 24.081738] [<803f1f80>] (nand_write_page) from [<803f3bd8>] (nand_do_write_ops+0x240/0x444) [ 24.090180] r8:00000400 r7:00000400 r6:9e674810 r5:803f1f80 r4:9e674b40 [ 24.096970] [<803f3998>] (nand_do_write_ops) from [<803f3f94>] (nand_write+0x68/0x88) [ 24.104804] r10:00000400 r9:00000000 r8:00580000 r7:9df42800 r6:9dcfdce8 r5:9dcfdc20 [ 24.112719] r4:9e674810 [ 24.115287] [<803f3f2c>] (nand_write) from [<803eb63c>] (part_write+0x48/0x50) [ 24.122514] r10:9d802000 r9:9dee1000 r8:9df42800 r7:00000000 r6:00000400 r5:00000000 [ 24.130429] r4:00580000 [ 24.132989] [<803eb5f4>] (part_write) from [<803e82ac>] (mtd_write+0x88/0xa0) [ 24.140129] r5:00000000 r4:803eb5f4 [ 24.143748] [<803e8224>] (mtd_write) from [<80406048>] (ubi_io_write+0x104/0x65c) [ 24.151235] r7:00000000 r6:00000400 r5:00000000 r4:9dee0000 [ 24.156968] [<80405f44>] (ubi_io_write) from [<804066cc>] (ubi_io_write_ec_hdr+0x12c/0x190) [ 24.165323] r10:9d802000 r9:9dc8b214 r8:00000000 r7:9d802030 r6:00000000 r5:9dee0000 [ 24.173239] r4:9df42800 [ 24.175798] [<804065a0>] (ubi_io_write_ec_hdr) from [<8040a544>] (ubi_early_get_peb+0x110/0x1f0) [ 24.184587] r6:9dc8b200 r5:9dee0000 r4:9df42800 [ 24.189262] [<8040a434>] (ubi_early_get_peb) from [<803fb560>] (create_vtbl+0x7c/0x238) [ 24.197271] r10:9dee0000 r9:9dc8b200 r8:9dc8b200 r7:9dc8b200 r6:00000080 r5:00000000 [ 24.205187] r4:9df42400 [ 24.207746] [<803fb4e4>] (create_vtbl) from [<803fc08c>] (ubi_read_volume_table+0x750/0xa64) [ 24.216187] r10:8112514c r9:9dc8b200 r8:a0acf000 r7:9dc8b200 r6:00000080 r5:00005600 [ 24.224103] r4:9dee0000 [ 24.226662] [<803fb93c>] (ubi_read_volume_table) from [<8040afa0>] (ubi_attach+0x97c/0x152c) [ 24.235103] r10:8112514c r9:9dc8b200 r8:00000001 r7:9dee0000 r6:00000065 r5:9dee0000 [ 24.243018] r4:00000000 [ 24.245579] [<8040a624>] (ubi_attach) from [<803ff1bc>] (ubi_attach_mtd_dev+0x630/0xbac) [ 24.253673] r10:9e7b5400 r9:00001000 r8:9dee1000 r7:9dee0000 r6:00000000 r5:9e7b5400 [ 24.261588] r4:fffff000 [ 24.264148] [<803feb8c>] (ubi_attach_mtd_dev) from [<804008cc>] (ctrl_cdev_ioctl+0xcc/0x1cc) [ 24.272589] r10:00000000 r9:9dcfc000 r8:00000003 r7:80113e30 r6:9e7b5400 r5:7e87ab70 [ 24.280505] r4:00000000 [ 24.283070] [<80400800>] (ctrl_cdev_ioctl) from [<80113b5c>] (do_vfs_ioctl+0x42c/0x6c4) [ 24.291077] r6:9dd92140 r5:7e87ab70 r4:9dc193e0 [ 24.295753] [<80113730>] (do_vfs_ioctl) from [<80113e30>] (SyS_ioctl+0x3c/0x64) [ 24.303066] r10:00000000 r9:9dcfc000 r8:7e87ab70 r7:40186f40 r6:9dd92140 r5:00000003 [ 24.310981] r4:9dd92140 [ 24.313549] [<80113df4>] (SyS_ioctl) from [<8000f9a0>] (ret_fast_syscall+0x0/0x54) [ 24.321123] r9:9dcfc000 r8:8000fb84 r7:00000036 r6:7e87aea9 r5:7e87ab70 r4:7e87ab70 [ 24.328957] Code: e1c300b0 e1510002 e1a03001 1afffff9 (e89da800) [ 24.335066] ---[ end trace ab1cb17887f21bbb ]--- [ 24.340249] Unhandled fault: imprecise external abort (0x1c06) at 0x7ee8bcf0 [ 24.347310] pgd = 9df3c000 [ 24.350023] [7ee8bcf0] *pgd=8dcbf831, *pte=8eb3334f, *ppte=8eb3383f Segmentation fault Fixes: 35d5d20 ("mtd: mxc_nand: cleanup copy_spare function") Signed-off-by: Eric Bénard <eric@eukrea.com> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Baruch Siach <baruch@tkos.co.il> Cc: <stable@vger.kernel.org> Signed-off-by: Brian Norris <computersforpeace@gmail.com>

My colleague ran into a program stall on a x86_64 server, where n_tty_read() was waiting for data even if there was data in the buffer in the pty. kernel stack for the stuck process looks like below. #0 [ffff88303d107b58] __schedule at ffffffff815c4b20 #1 [ffff88303d107bd0] schedule at ffffffff815c513e #2 [ffff88303d107bf0] schedule_timeout at ffffffff815c7818 #3 [ffff88303d107ca0] wait_woken at ffffffff81096bd2 #4 [ffff88303d107ce0] n_tty_read at ffffffff8136fa23 #5 [ffff88303d107dd0] tty_read at ffffffff81368013 torvalds#6 [ffff88303d107e20] __vfs_read at ffffffff811a3704 torvalds#7 [ffff88303d107ec0] vfs_read at ffffffff811a3a57 torvalds#8 [ffff88303d107f00] sys_read at ffffffff811a4306 torvalds#9 [ffff88303d107f50] entry_SYSCALL_64_fastpath at ffffffff815c86d7 There seems to be two problems causing this issue. First, in drivers/tty/n_tty.c, __receive_buf() stores the data and updates ldata->commit_head using smp_store_release() and then checks the wait queue using waitqueue_active(). However, since there is no memory barrier, __receive_buf() could return without calling wake_up_interactive_poll(), and at the same time, n_tty_read() could start to wait in wait_woken() as in the following chart. __receive_buf() n_tty_read() ------------------------------------------------------------------------ if (waitqueue_active(&tty->read_wait)) /* Memory operations issued after the RELEASE may be completed before the RELEASE operation has completed */ add_wait_queue(&tty->read_wait, &wait); ... if (!input_available_p(tty, 0)) { smp_store_release(&ldata->commit_head, ldata->read_head); ... timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout); ------------------------------------------------------------------------ The second problem is that n_tty_read() also lacks a memory barrier call and could also cause __receive_buf() to return without calling wake_up_interactive_poll(), and n_tty_read() to wait in wait_woken() as in the chart below. __receive_buf() n_tty_read() ------------------------------------------------------------------------ spin_lock_irqsave(&q->lock, flags); /* from add_wait_queue() */ ... if (!input_available_p(tty, 0)) { /* Memory operations issued after the RELEASE may be completed before the RELEASE operation has completed */ smp_store_release(&ldata->commit_head, ldata->read_head); if (waitqueue_active(&tty->read_wait)) __add_wait_queue(q, wait); spin_unlock_irqrestore(&q->lock,flags); /* from add_wait_queue() */ ... timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout); ------------------------------------------------------------------------ There are also other places in drivers/tty/n_tty.c which have similar calls to waitqueue_active(), so instead of adding many memory barrier calls, this patch simply removes the call to waitqueue_active(), leaving just wake_up*() behind. This fixes both problems because, even though the memory access before or after the spinlocks in both wake_up*() and add_wait_queue() can sneak into the critical section, it cannot go past it and the critical section assures that they will be serialized (please see "INTER-CPU ACQUIRING BARRIER EFFECTS" in Documentation/memory-barriers.txt for a better explanation). Moreover, the resulting code is much simpler. Latency measurement using a ping-pong test over a pty doesn't show any visible performance drop. Signed-off-by: Kosuke Tatsukawa <tatsu@ab.jp.nec.com> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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powercap / RAPL: disable the 2nd power limit properly #1

powercap / RAPL: disable the 2nd power limit properly #1

sikarash commented Aug 27, 2015

powercap / RAPL: disable the 2nd power limit properly #1

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powercap / RAPL: disable the 2nd power limit properly #1

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sikarash commented Aug 27, 2015