watchdog: kvims: update watchdog driver#2
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[ Upstream commit d754941 ] If, for any reason, userland shuts down iscsi transport interfaces before proper logouts - like when logging in to LUNs manually, without logging out on server shutdown, or when automated scripts can't umount/logout from logged LUNs - kernel will hang forever on its sd_sync_cache() logic, after issuing the SYNCHRONIZE_CACHE cmd to all still existent paths. PID: 1 TASK: ffff8801a69b8000 CPU: 1 COMMAND: "systemd-shutdow" #0 [ffff8801a69c3a30] __schedule at ffffffff8183e9ee #1 [ffff8801a69c3a80] schedule at ffffffff8183f0d5 #2 [ffff8801a69c3a98] schedule_timeout at ffffffff81842199 #3 [ffff8801a69c3b40] io_schedule_timeout at ffffffff8183e604 #4 [ffff8801a69c3b70] wait_for_completion_io_timeout at ffffffff8183fc6c khadas#5 [ffff8801a69c3bd0] blk_execute_rq at ffffffff813cfe10 khadas#6 [ffff8801a69c3c88] scsi_execute at ffffffff815c3fc7 khadas#7 [ffff8801a69c3cc8] scsi_execute_req_flags at ffffffff815c60fe khadas#8 [ffff8801a69c3d30] sd_sync_cache at ffffffff815d37d7 khadas#9 [ffff8801a69c3da8] sd_shutdown at ffffffff815d3c3c This happens because iscsi_eh_cmd_timed_out(), the transport layer timeout helper, would tell the queue timeout function (scsi_times_out) to reset the request timer over and over, until the session state is back to logged in state. Unfortunately, during server shutdown, this might never happen again. Other option would be "not to handle" the issue in the transport layer. That would trigger the error handler logic, which would also need the session state to be logged in again. Best option, for such case, is to tell upper layers that the command was handled during the transport layer error handler helper, marking it as DID_NO_CONNECT, which will allow completion and inform about the problem. After the session was marked as ISCSI_STATE_FAILED, due to the first timeout during the server shutdown phase, all subsequent cmds will fail to be queued, allowing upper logic to fail faster. Signed-off-by: Rafael David Tinoco <rafael.tinoco@canonical.com> Reviewed-by: Lee Duncan <lduncan@suse.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit c755e25 upstream. The xattr_sem deadlock problems fixed in commit 2e81a4e: "ext4: avoid deadlock when expanding inode size" didn't include the use of xattr_sem in fs/ext4/inline.c. With the addition of project quota which added a new extra inode field, this exposed deadlocks in the inline_data code similar to the ones fixed by 2e81a4e. The deadlock can be reproduced via: dmesg -n 7 mke2fs -t ext4 -O inline_data -Fq -I 256 /dev/vdc 32768 mount -t ext4 -o debug_want_extra_isize=24 /dev/vdc /vdc mkdir /vdc/a umount /vdc mount -t ext4 /dev/vdc /vdc echo foo > /vdc/a/foo and looks like this: [ 11.158815] [ 11.160276] ============================================= [ 11.161960] [ INFO: possible recursive locking detected ] [ 11.161960] 4.10.0-rc3-00015-g011b30a8a3cf khadas#160 Tainted: G W [ 11.161960] --------------------------------------------- [ 11.161960] bash/2519 is trying to acquire lock: [ 11.161960] (&ei->xattr_sem){++++..}, at: [<c1225a4b>] ext4_expand_extra_isize_ea+0x3d/0x4cd [ 11.161960] [ 11.161960] but task is already holding lock: [ 11.161960] (&ei->xattr_sem){++++..}, at: [<c1227941>] ext4_try_add_inline_entry+0x3a/0x152 [ 11.161960] [ 11.161960] other info that might help us debug this: [ 11.161960] Possible unsafe locking scenario: [ 11.161960] [ 11.161960] CPU0 [ 11.161960] ---- [ 11.161960] lock(&ei->xattr_sem); [ 11.161960] lock(&ei->xattr_sem); [ 11.161960] [ 11.161960] *** DEADLOCK *** [ 11.161960] [ 11.161960] May be due to missing lock nesting notation [ 11.161960] [ 11.161960] 4 locks held by bash/2519: [ 11.161960] #0: (sb_writers#3){.+.+.+}, at: [<c11a2414>] mnt_want_write+0x1e/0x3e [ 11.161960] #1: (&type->i_mutex_dir_key){++++++}, at: [<c119508b>] path_openat+0x338/0x67a [ 11.161960] #2: (jbd2_handle){++++..}, at: [<c123314a>] start_this_handle+0x582/0x622 [ 11.161960] #3: (&ei->xattr_sem){++++..}, at: [<c1227941>] ext4_try_add_inline_entry+0x3a/0x152 [ 11.161960] [ 11.161960] stack backtrace: [ 11.161960] CPU: 0 PID: 2519 Comm: bash Tainted: G W 4.10.0-rc3-00015-g011b30a8a3cf khadas#160 [ 11.161960] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.1-1 04/01/2014 [ 11.161960] Call Trace: [ 11.161960] dump_stack+0x72/0xa3 [ 11.161960] __lock_acquire+0xb7c/0xcb9 [ 11.161960] ? kvm_clock_read+0x1f/0x29 [ 11.161960] ? __lock_is_held+0x36/0x66 [ 11.161960] ? __lock_is_held+0x36/0x66 [ 11.161960] lock_acquire+0x106/0x18a [ 11.161960] ? ext4_expand_extra_isize_ea+0x3d/0x4cd [ 11.161960] down_write+0x39/0x72 [ 11.161960] ? ext4_expand_extra_isize_ea+0x3d/0x4cd [ 11.161960] ext4_expand_extra_isize_ea+0x3d/0x4cd [ 11.161960] ? _raw_read_unlock+0x22/0x2c [ 11.161960] ? jbd2_journal_extend+0x1e2/0x262 [ 11.161960] ? __ext4_journal_get_write_access+0x3d/0x60 [ 11.161960] ext4_mark_inode_dirty+0x17d/0x26d [ 11.161960] ? ext4_add_dirent_to_inline.isra.12+0xa5/0xb2 [ 11.161960] ext4_add_dirent_to_inline.isra.12+0xa5/0xb2 [ 11.161960] ext4_try_add_inline_entry+0x69/0x152 [ 11.161960] ext4_add_entry+0xa3/0x848 [ 11.161960] ? __brelse+0x14/0x2f [ 11.161960] ? _raw_spin_unlock_irqrestore+0x44/0x4f [ 11.161960] ext4_add_nondir+0x17/0x5b [ 11.161960] ext4_create+0xcf/0x133 [ 11.161960] ? ext4_mknod+0x12f/0x12f [ 11.161960] lookup_open+0x39e/0x3fb [ 11.161960] ? __wake_up+0x1a/0x40 [ 11.161960] ? lock_acquire+0x11e/0x18a [ 11.161960] path_openat+0x35c/0x67a [ 11.161960] ? sched_clock_cpu+0xd7/0xf2 [ 11.161960] do_filp_open+0x36/0x7c [ 11.161960] ? _raw_spin_unlock+0x22/0x2c [ 11.161960] ? __alloc_fd+0x169/0x173 [ 11.161960] do_sys_open+0x59/0xcc [ 11.161960] SyS_open+0x1d/0x1f [ 11.161960] do_int80_syscall_32+0x4f/0x61 [ 11.161960] entry_INT80_32+0x2f/0x2f [ 11.161960] EIP: 0xb76ad469 [ 11.161960] EFLAGS: 00000286 CPU: 0 [ 11.161960] EAX: ffffffda EBX: 08168ac8 ECX: 00008241 EDX: 000001b6 [ 11.161960] ESI: b75e46bc EDI: b7755000 EBP: bfbdb108 ESP: bfbdafc0 [ 11.161960] DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b Cc: stable@vger.kernel.org # 3.10 (requires 2e81a4e as a prereq) Reported-by: George Spelvin <linux@sciencehorizons.net> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 9c438d7 ] Adding a dns_resolver key whose payload contains a very long option name resulted in that string being printed in full. This hit the WARN_ONCE() in set_precision() during the printk(), because printk() only supports a precision of up to 32767 bytes: precision 1000000 too large WARNING: CPU: 0 PID: 752 at lib/vsprintf.c:2189 vsnprintf+0x4bc/0x5b0 Fix it by limiting option strings (combined name + value) to a much more reasonable 128 bytes. The exact limit is arbitrary, but currently the only recognized option is formatted as "dnserror=%lu" which fits well within this limit. Also ratelimit the printks. Reproducer: perl -e 'print "#", "A" x 1000000, "\x00"' | keyctl padd dns_resolver desc @s This bug was found using syzkaller. Reported-by: Mark Rutland <mark.rutland@arm.com> Fixes: 4a2d789 ("DNS: If the DNS server returns an error, allow that to be cached [ver #2]") Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 5c64576 upstream. syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2] We have 2 problems in start_sync_thread if error path is taken, eg. on memory allocation error or failure to configure sockets for mcast group or addr/port binding: 1. recursive locking: holding rtnl_lock while calling sock_release which in turn calls again rtnl_lock in ip_mc_drop_socket to leave the mcast group, as noticed by Florian Westphal. Additionally, sock_release can not be called while holding sync_mutex (ABBA deadlock). 2. task hung: holding rtnl_lock while calling kthread_stop to stop the running kthreads. As the kthreads do the same to leave the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock) they hang. Fix the problems by calling rtnl_unlock early in the error path, now sock_release is called after unlocking both mutexes. Problem 3 (task hung reported by syzkaller [2]) is variant of problem 2: use _trylock to prevent one user to call rtnl_lock and then while waiting for sync_mutex to block kthreads that execute sock_release when they are stopped by stop_sync_thread. [1] IPVS: stopping backup sync thread 4500 ... WARNING: possible recursive locking detected 4.16.0-rc7+ #3 Not tainted -------------------------------------------- syzkaller688027/4497 is trying to acquire lock: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 but task is already holding lock: IPVS: stopping backup sync thread 4495 ... (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(rtnl_mutex); lock(rtnl_mutex); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by syzkaller688027/4497: #0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 #1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>] do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388 stack backtrace: CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x24d lib/dump_stack.c:53 print_deadlock_bug kernel/locking/lockdep.c:1761 [inline] check_deadlock kernel/locking/lockdep.c:1805 [inline] validate_chain kernel/locking/lockdep.c:2401 [inline] __lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643 inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413 sock_release+0x8d/0x1e0 net/socket.c:595 start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924 do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline] nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115 ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261 udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406 sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975 SYSC_setsockopt net/socket.c:1849 [inline] SyS_setsockopt+0x189/0x360 net/socket.c:1828 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x446a69 RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69 RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000 R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8 R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60 [2] IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4, id = 0 IPVS: stopping backup sync thread 25415 ... INFO: task syz-executor7:25421 blocked for more than 120 seconds. Not tainted 4.16.0-rc6+ #284 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor7 D23688 25421 4408 0x00000004 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440 schedule+0xf5/0x430 kernel/sched/core.c:3499 schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777 do_wait_for_common kernel/sched/completion.c:86 [inline] __wait_for_common kernel/sched/completion.c:107 [inline] wait_for_common kernel/sched/completion.c:118 [inline] wait_for_completion+0x415/0x770 kernel/sched/completion.c:139 kthread_stop+0x14a/0x7a0 kernel/kthread.c:530 stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996 do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline] nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115 ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253 sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154 sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039 SYSC_setsockopt net/socket.c:1850 [inline] SyS_setsockopt+0x189/0x360 net/socket.c:1829 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x454889 RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889 RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017 RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000 R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001 Showing all locks held in the system: 2 locks held by khungtaskd/868: #0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>] debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470 1 lock held by rsyslogd/4247: #0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>] __fdget_pos+0x12b/0x190 fs/file.c:765 2 locks held by getty/4338: #0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4339: #0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4340: #0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4341: #0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4342: #0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4343: #0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4344: #0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 3 locks held by kworker/0:5/6494: #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline] #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline] #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084 #1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088 #2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 1 lock held by syz-executor7/25421: #0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>] do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393 2 locks held by syz-executor7/25427: #0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 #1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>] do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388 1 lock held by syz-executor7/25435: #0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 1 lock held by ipvs-b:2:0/25415: #0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com Fixes: e0b26cc ("ipvs: call rtnl_lock early") Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Simon Horman <horms@verge.net.au> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Cc: Zubin Mithra <zsm@chromium.org> Cc: Guenter Roeck <groeck@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit fba9eb7 ] Add a header with macros usable in assembler files to emit alternative code sequences. It works analog to the alternatives for inline assmeblies in C files, with the same restrictions and capabilities. The syntax is ALTERNATIVE "<default instructions sequence>", \ "<alternative instructions sequence>", \ "<features-bit>" and ALTERNATIVE_2 "<default instructions sequence>", \ "<alternative instructions sqeuence #1>", \ "<feature-bit #1>", "<alternative instructions sqeuence #2>", \ "<feature-bit #2>" Reviewed-by: Vasily Gorbik <gor@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 2c0aa08 ] Scenario: 1. Port down and do fail over 2. Ap do rds_bind syscall PID: 47039 TASK: ffff89887e2fe640 CPU: 47 COMMAND: "kworker/u:6" #0 [ffff898e35f159f0] machine_kexec at ffffffff8103abf9 #1 [ffff898e35f15a60] crash_kexec at ffffffff810b96e3 #2 [ffff898e35f15b30] oops_end at ffffffff8150f518 #3 [ffff898e35f15b60] no_context at ffffffff8104854c #4 [ffff898e35f15ba0] __bad_area_nosemaphore at ffffffff81048675 khadas#5 [ffff898e35f15bf0] bad_area_nosemaphore at ffffffff810487d3 khadas#6 [ffff898e35f15c00] do_page_fault at ffffffff815120b8 khadas#7 [ffff898e35f15d10] page_fault at ffffffff8150ea95 [exception RIP: unknown or invalid address] RIP: 0000000000000000 RSP: ffff898e35f15dc8 RFLAGS: 00010282 RAX: 00000000fffffffe RBX: ffff889b77f6fc00 RCX:ffffffff81c99d88 RDX: 0000000000000000 RSI: ffff896019ee08e8 RDI:ffff889b77f6fc00 RBP: ffff898e35f15df0 R8: ffff896019ee08c8 R9:0000000000000000 R10: 0000000000000400 R11: 0000000000000000 R12:ffff896019ee08c0 R13: ffff889b77f6fe68 R14: ffffffff81c99d80 R15: ffffffffa022a1e0 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 khadas#8 [ffff898e35f15dc8] cma_ndev_work_handler at ffffffffa022a228 [rdma_cm] khadas#9 [ffff898e35f15df8] process_one_work at ffffffff8108a7c6 khadas#10 [ffff898e35f15e58] worker_thread at ffffffff8108bda0 khadas#11 [ffff898e35f15ee8] kthread at ffffffff81090fe6 PID: 45659 TASK: ffff880d313d2500 CPU: 31 COMMAND: "oracle_45659_ap" #0 [ffff881024ccfc98] __schedule at ffffffff8150bac4 #1 [ffff881024ccfd40] schedule at ffffffff8150c2cf #2 [ffff881024ccfd50] __mutex_lock_slowpath at ffffffff8150cee7 #3 [ffff881024ccfdc0] mutex_lock at ffffffff8150cdeb #4 [ffff881024ccfde0] rdma_destroy_id at ffffffffa022a027 [rdma_cm] khadas#5 [ffff881024ccfe10] rds_ib_laddr_check at ffffffffa0357857 [rds_rdma] khadas#6 [ffff881024ccfe50] rds_trans_get_preferred at ffffffffa0324c2a [rds] khadas#7 [ffff881024ccfe80] rds_bind at ffffffffa031d690 [rds] khadas#8 [ffff881024ccfeb0] sys_bind at ffffffff8142a670 PID: 45659 PID: 47039 rds_ib_laddr_check /* create id_priv with a null event_handler */ rdma_create_id rdma_bind_addr cma_acquire_dev /* add id_priv to cma_dev->id_list */ cma_attach_to_dev cma_ndev_work_handler /* event_hanlder is null */ id_priv->id.event_handler Signed-off-by: Guanglei Li <guanglei.li@oracle.com> Signed-off-by: Honglei Wang <honglei.wang@oracle.com> Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com> Reviewed-by: Yanjun Zhu <yanjun.zhu@oracle.com> Reviewed-by: Leon Romanovsky <leonro@mellanox.com> Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Acked-by: Doug Ledford <dledford@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit b6dd4d8 ] The pr_debug() in gic-v3 gic_send_sgi() can trigger a circular locking warning: GICv3: CPU10: ICC_SGI1R_EL1 5000400 ====================================================== WARNING: possible circular locking dependency detected 4.15.0+ #1 Tainted: G W ------------------------------------------------------ dynamic_debug01/1873 is trying to acquire lock: ((console_sem).lock){-...}, at: [<0000000099c891ec>] down_trylock+0x20/0x4c but task is already holding lock: (&rq->lock){-.-.}, at: [<00000000842e1587>] __task_rq_lock+0x54/0xdc which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&rq->lock){-.-.}: __lock_acquire+0x3b4/0x6e0 lock_acquire+0xf4/0x2a8 _raw_spin_lock+0x4c/0x60 task_fork_fair+0x3c/0x148 sched_fork+0x10c/0x214 copy_process.isra.32.part.33+0x4e8/0x14f0 _do_fork+0xe8/0x78c kernel_thread+0x48/0x54 rest_init+0x34/0x2a4 start_kernel+0x45c/0x488 -> #1 (&p->pi_lock){-.-.}: __lock_acquire+0x3b4/0x6e0 lock_acquire+0xf4/0x2a8 _raw_spin_lock_irqsave+0x58/0x70 try_to_wake_up+0x48/0x600 wake_up_process+0x28/0x34 __up.isra.0+0x60/0x6c up+0x60/0x68 __up_console_sem+0x4c/0x7c console_unlock+0x328/0x634 vprintk_emit+0x25c/0x390 dev_vprintk_emit+0xc4/0x1fc dev_printk_emit+0x88/0xa8 __dev_printk+0x58/0x9c _dev_info+0x84/0xa8 usb_new_device+0x100/0x474 hub_port_connect+0x280/0x92c hub_event+0x740/0xa84 process_one_work+0x240/0x70c worker_thread+0x60/0x400 kthread+0x110/0x13c ret_from_fork+0x10/0x18 -> #0 ((console_sem).lock){-...}: validate_chain.isra.34+0x6e4/0xa20 __lock_acquire+0x3b4/0x6e0 lock_acquire+0xf4/0x2a8 _raw_spin_lock_irqsave+0x58/0x70 down_trylock+0x20/0x4c __down_trylock_console_sem+0x3c/0x9c console_trylock+0x20/0xb0 vprintk_emit+0x254/0x390 vprintk_default+0x58/0x90 vprintk_func+0xbc/0x164 printk+0x80/0xa0 __dynamic_pr_debug+0x84/0xac gic_raise_softirq+0x184/0x18c smp_cross_call+0xac/0x218 smp_send_reschedule+0x3c/0x48 resched_curr+0x60/0x9c check_preempt_curr+0x70/0xdc wake_up_new_task+0x310/0x470 _do_fork+0x188/0x78c SyS_clone+0x44/0x50 __sys_trace_return+0x0/0x4 other info that might help us debug this: Chain exists of: (console_sem).lock --> &p->pi_lock --> &rq->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&rq->lock); lock(&p->pi_lock); lock(&rq->lock); lock((console_sem).lock); *** DEADLOCK *** 2 locks held by dynamic_debug01/1873: #0: (&p->pi_lock){-.-.}, at: [<000000001366df53>] wake_up_new_task+0x40/0x470 #1: (&rq->lock){-.-.}, at: [<00000000842e1587>] __task_rq_lock+0x54/0xdc stack backtrace: CPU: 10 PID: 1873 Comm: dynamic_debug01 Tainted: G W 4.15.0+ #1 Hardware name: GIGABYTE R120-T34-00/MT30-GS2-00, BIOS T48 10/02/2017 Call trace: dump_backtrace+0x0/0x188 show_stack+0x24/0x2c dump_stack+0xa4/0xe0 print_circular_bug.isra.31+0x29c/0x2b8 check_prev_add.constprop.39+0x6c8/0x6dc validate_chain.isra.34+0x6e4/0xa20 __lock_acquire+0x3b4/0x6e0 lock_acquire+0xf4/0x2a8 _raw_spin_lock_irqsave+0x58/0x70 down_trylock+0x20/0x4c __down_trylock_console_sem+0x3c/0x9c console_trylock+0x20/0xb0 vprintk_emit+0x254/0x390 vprintk_default+0x58/0x90 vprintk_func+0xbc/0x164 printk+0x80/0xa0 __dynamic_pr_debug+0x84/0xac gic_raise_softirq+0x184/0x18c smp_cross_call+0xac/0x218 smp_send_reschedule+0x3c/0x48 resched_curr+0x60/0x9c check_preempt_curr+0x70/0xdc wake_up_new_task+0x310/0x470 _do_fork+0x188/0x78c SyS_clone+0x44/0x50 __sys_trace_return+0x0/0x4 GICv3: CPU0: ICC_SGI1R_EL1 12000 This could be fixed with printk_deferred() but that might lessen its usefulness for debugging. So change it to pr_devel to keep it out of production kernels. Developers working on gic-v3 can enable it as needed in their kernels. Signed-off-by: Mark Salter <msalter@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 2bbea6e ] when mounting an ISO filesystem sometimes (very rarely) the system hangs because of a race condition between two tasks. PID: 6766 TASK: ffff88007b2a6dd0 CPU: 0 COMMAND: "mount" #0 [ffff880078447ae0] __schedule at ffffffff8168d605 #1 [ffff880078447b48] schedule_preempt_disabled at ffffffff8168ed49 #2 [ffff880078447b58] __mutex_lock_slowpath at ffffffff8168c995 #3 [ffff880078447bb8] mutex_lock at ffffffff8168bdef #4 [ffff880078447bd0] sr_block_ioctl at ffffffffa00b6818 [sr_mod] khadas#5 [ffff880078447c10] blkdev_ioctl at ffffffff812fea50 khadas#6 [ffff880078447c70] ioctl_by_bdev at ffffffff8123a8b3 khadas#7 [ffff880078447c90] isofs_fill_super at ffffffffa04fb1e1 [isofs] khadas#8 [ffff880078447da8] mount_bdev at ffffffff81202570 khadas#9 [ffff880078447e18] isofs_mount at ffffffffa04f9828 [isofs] khadas#10 [ffff880078447e28] mount_fs at ffffffff81202d09 khadas#11 [ffff880078447e70] vfs_kern_mount at ffffffff8121ea8f khadas#12 [ffff880078447ea8] do_mount at ffffffff81220fee khadas#13 [ffff880078447f28] sys_mount at ffffffff812218d6 khadas#14 [ffff880078447f80] system_call_fastpath at ffffffff81698c49 RIP: 00007fd9ea914e9a RSP: 00007ffd5d9bf648 RFLAGS: 00010246 RAX: 00000000000000a5 RBX: ffffffff81698c49 RCX: 0000000000000010 RDX: 00007fd9ec2bc210 RSI: 00007fd9ec2bc290 RDI: 00007fd9ec2bcf30 RBP: 0000000000000000 R8: 0000000000000000 R9: 0000000000000010 R10: 00000000c0ed0001 R11: 0000000000000206 R12: 00007fd9ec2bc040 R13: 00007fd9eb6b2380 R14: 00007fd9ec2bc210 R15: 00007fd9ec2bcf30 ORIG_RAX: 00000000000000a5 CS: 0033 SS: 002b This task was trying to mount the cdrom. It allocated and configured a super_block struct and owned the write-lock for the super_block->s_umount rwsem. While exclusively owning the s_umount lock, it called sr_block_ioctl and waited to acquire the global sr_mutex lock. PID: 6785 TASK: ffff880078720fb0 CPU: 0 COMMAND: "systemd-udevd" #0 [ffff880078417898] __schedule at ffffffff8168d605 #1 [ffff880078417900] schedule at ffffffff8168dc59 #2 [ffff880078417910] rwsem_down_read_failed at ffffffff8168f605 #3 [ffff880078417980] call_rwsem_down_read_failed at ffffffff81328838 #4 [ffff8800784179d0] down_read at ffffffff8168cde0 khadas#5 [ffff8800784179e8] get_super at ffffffff81201cc7 khadas#6 [ffff880078417a10] __invalidate_device at ffffffff8123a8de khadas#7 [ffff880078417a40] flush_disk at ffffffff8123a94b khadas#8 [ffff880078417a88] check_disk_change at ffffffff8123ab50 khadas#9 [ffff880078417ab0] cdrom_open at ffffffffa00a29e1 [cdrom] khadas#10 [ffff880078417b68] sr_block_open at ffffffffa00b6f9b [sr_mod] khadas#11 [ffff880078417b98] __blkdev_get at ffffffff8123ba86 khadas#12 [ffff880078417bf0] blkdev_get at ffffffff8123bd65 khadas#13 [ffff880078417c78] blkdev_open at ffffffff8123bf9b khadas#14 [ffff880078417c90] do_dentry_open at ffffffff811fc7f7 khadas#15 [ffff880078417cd8] vfs_open at ffffffff811fc9cf khadas#16 [ffff880078417d00] do_last at ffffffff8120d53d khadas#17 [ffff880078417db0] path_openat at ffffffff8120e6b2 khadas#18 [ffff880078417e48] do_filp_open at ffffffff8121082b khadas#19 [ffff880078417f18] do_sys_open at ffffffff811fdd33 khadas#20 [ffff880078417f70] sys_open at ffffffff811fde4e khadas#21 [ffff880078417f80] system_call_fastpath at ffffffff81698c49 RIP: 00007f29438b0c20 RSP: 00007ffc76624b78 RFLAGS: 00010246 RAX: 0000000000000002 RBX: ffffffff81698c49 RCX: 0000000000000000 RDX: 00007f2944a5fa70 RSI: 00000000000a0800 RDI: 00007f2944a5fa70 RBP: 00007f2944a5f540 R8: 0000000000000000 R9: 0000000000000020 R10: 00007f2943614c40 R11: 0000000000000246 R12: ffffffff811fde4e R13: ffff880078417f78 R14: 000000000000000c R15: 00007f2944a4b010 ORIG_RAX: 0000000000000002 CS: 0033 SS: 002b This task tried to open the cdrom device, the sr_block_open function acquired the global sr_mutex lock. The call to check_disk_change() then saw an event flag indicating a possible media change and tried to flush any cached data for the device. As part of the flush, it tried to acquire the super_block->s_umount lock associated with the cdrom device. This was the same super_block as created and locked by the previous task. The first task acquires the s_umount lock and then the sr_mutex_lock; the second task acquires the sr_mutex_lock and then the s_umount lock. This patch fixes the issue by moving check_disk_change() out of cdrom_open() and let the caller take care of it. Signed-off-by: Maurizio Lombardi <mlombard@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit a3ca831 ] When booting up with "threadirqs" in command line, all irq handlers of the DMA controller pl330 will be threaded forcedly. These threads will race for the same list, pl330->req_done. Before the callback, the spinlock was released. And after it, the spinlock was taken. This opened an race window where another threaded irq handler could steal the spinlock and be permitted to delete entries of the list, pl330->req_done. If the later deleted an entry that was still referred to by the former, there would be a kernel panic when the former was scheduled and tried to get the next sibling of the deleted entry. The scenario could be depicted as below: Thread: T1 pl330->req_done Thread: T2 | | | | -A-B-C-D- | Locked | | | | Waiting Del A | | | -B-C-D- | Unlocked | | | | Locked Waiting | | | | Del B | | | | -C-D- Unlocked Waiting | | | Locked | get C via B \ - Kernel panic The kernel panic looked like as below: Unable to handle kernel paging request at virtual address dead000000000108 pgd = ffffff8008c9e000 [dead000000000108] *pgd=000000027fffe003, *pud=000000027fffe003, *pmd=0000000000000000 Internal error: Oops: 96000044 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 85 Comm: irq/59-66330000 Not tainted 4.8.24-WR9.0.0.12_standard #2 Hardware name: Broadcom NS2 SVK (DT) task: ffffffc1f5cc3c00 task.stack: ffffffc1f5ce0000 PC is at pl330_irq_handler+0x27c/0x390 LR is at pl330_irq_handler+0x2a8/0x390 pc : [<ffffff80084cb694>] lr : [<ffffff80084cb6c0>] pstate: 800001c5 sp : ffffffc1f5ce3d00 x29: ffffffc1f5ce3d00 x28: 0000000000000140 x27: ffffffc1f5c530b0 x26: dead000000000100 x25: dead000000000200 x24: 0000000000418958 x23: 0000000000000001 x22: ffffffc1f5ccd668 x21: ffffffc1f5ccd590 x20: ffffffc1f5ccd418 x19: dead000000000060 x18: 0000000000000001 x17: 0000000000000007 x16: 0000000000000001 x15: ffffffffffffffff x14: ffffffffffffffff x13: ffffffffffffffff x12: 0000000000000000 x11: 0000000000000001 x10: 0000000000000840 x9 : ffffffc1f5ce0000 x8 : ffffffc1f5cc3338 x7 : ffffff8008ce2020 x6 : 0000000000000000 x5 : 0000000000000000 x4 : 0000000000000001 x3 : dead000000000200 x2 : dead000000000100 x1 : 0000000000000140 x0 : ffffffc1f5ccd590 Process irq/59-66330000 (pid: 85, stack limit = 0xffffffc1f5ce0020) Stack: (0xffffffc1f5ce3d00 to 0xffffffc1f5ce4000) 3d00: ffffffc1f5ce3d80 ffffff80080f09d0 ffffffc1f5ca0c00 ffffffc1f6f7c600 3d20: ffffffc1f5ce0000 ffffffc1f6f7c600 ffffffc1f5ca0c00 ffffff80080f0998 3d40: ffffffc1f5ce0000 ffffff80080f0000 0000000000000000 0000000000000000 3d60: ffffff8008ce202c ffffff8008ce2020 ffffffc1f5ccd668 ffffffc1f5c530b0 3d80: ffffffc1f5ce3db0 ffffff80080f0d70 ffffffc1f5ca0c40 0000000000000001 3da0: ffffffc1f5ce0000 ffffff80080f0cfc ffffffc1f5ce3e20 ffffff80080bf4f8 3dc0: ffffffc1f5ca0c80 ffffff8008bf3798 ffffff8008955528 ffffffc1f5ca0c00 3de0: ffffff80080f0c30 0000000000000000 0000000000000000 0000000000000000 3e00: 0000000000000000 0000000000000000 0000000000000000 ffffff80080f0b68 3e20: 0000000000000000 ffffff8008083690 ffffff80080bf420 ffffffc1f5ca0c80 3e40: 0000000000000000 0000000000000000 0000000000000000 ffffff80080cb648 3e60: ffffff8008b1c780 0000000000000000 0000000000000000 ffffffc1f5ca0c00 3e80: ffffffc100000000 ffffff8000000000 ffffffc1f5ce3e90 ffffffc1f5ce3e90 3ea0: 0000000000000000 ffffff8000000000 ffffffc1f5ce3eb0 ffffffc1f5ce3eb0 3ec0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 3ee0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 3f00: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 3f20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 3f40: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 3f60: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 3f80: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 3fa0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 3fc0: 0000000000000000 0000000000000005 0000000000000000 0000000000000000 3fe0: 0000000000000000 0000000000000000 0000000275ce3ff0 0000000275ce3ff8 Call trace: Exception stack(0xffffffc1f5ce3b30 to 0xffffffc1f5ce3c60) 3b20: dead000000000060 0000008000000000 3b40: ffffffc1f5ce3d00 ffffff80084cb694 0000000000000008 0000000000000e88 3b60: ffffffc1f5ce3bb0 ffffff80080dac68 ffffffc1f5ce3b90 ffffff8008826fe4 3b80: 00000000000001c0 00000000000001c0 ffffffc1f5ce3bb0 ffffff800848dfcc 3ba0: 0000000000020000 ffffff8008b15ae4 ffffffc1f5ce3c00 ffffff800808f000 3bc0: 0000000000000010 ffffff80088377f0 ffffffc1f5ccd590 0000000000000140 3be0: dead000000000100 dead000000000200 0000000000000001 0000000000000000 3c00: 0000000000000000 ffffff8008ce2020 ffffffc1f5cc3338 ffffffc1f5ce0000 3c20: 0000000000000840 0000000000000001 0000000000000000 ffffffffffffffff 3c40: ffffffffffffffff ffffffffffffffff 0000000000000001 0000000000000007 [<ffffff80084cb694>] pl330_irq_handler+0x27c/0x390 [<ffffff80080f09d0>] irq_forced_thread_fn+0x38/0x88 [<ffffff80080f0d70>] irq_thread+0x140/0x200 [<ffffff80080bf4f8>] kthread+0xd8/0xf0 [<ffffff8008083690>] ret_from_fork+0x10/0x40 Code: f2a00838 f9405763 aa1c03e1 aa1503e0 (f9000443) ---[ end trace f50005726d31199c ]--- Kernel panic - not syncing: Fatal exception in interrupt SMP: stopping secondary CPUs SMP: failed to stop secondary CPUs 0-1 Kernel Offset: disabled Memory Limit: none ---[ end Kernel panic - not syncing: Fatal exception in interrupt To fix this, re-start with the list-head after dropping the lock then re-takeing it. Reviewed-by: Frank Mori Hess <fmh6jj@gmail.com> Tested-by: Frank Mori Hess <fmh6jj@gmail.com> Signed-off-by: Qi Hou <qi.hou@windriver.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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While testing the deadline scheduler + cgroup setup I hit this warning. [ 132.612935] ------------[ cut here ]------------ [ 132.612951] WARNING: CPU: 5 PID: 0 at kernel/softirq.c:150 __local_bh_enable_ip+0x6b/0x80 [ 132.612952] Modules linked in: (a ton of modules...) [ 132.612981] CPU: 5 PID: 0 Comm: swapper/5 Not tainted 4.7.0-rc2 #2 [ 132.612981] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.2-20150714_191134- 04/01/2014 [ 132.612982] 0000000000000086 45c8bb5effdd088b ffff88013fd43da0 ffffffff813d229e [ 132.612984] 0000000000000000 0000000000000000 ffff88013fd43de0 ffffffff810a652b [ 132.612985] 00000096811387b5 0000000000000200 ffff8800bab29d80 ffff880034c54c00 [ 132.612986] Call Trace: [ 132.612987] <IRQ> [<ffffffff813d229e>] dump_stack+0x63/0x85 [ 132.612994] [<ffffffff810a652b>] __warn+0xcb/0xf0 [ 132.612997] [<ffffffff810e76a0>] ? push_dl_task.part.32+0x170/0x170 [ 132.612999] [<ffffffff810a665d>] warn_slowpath_null+0x1d/0x20 [ 132.613000] [<ffffffff810aba5b>] __local_bh_enable_ip+0x6b/0x80 [ 132.613008] [<ffffffff817d6c8a>] _raw_write_unlock_bh+0x1a/0x20 [ 132.613010] [<ffffffff817d6c9e>] _raw_spin_unlock_bh+0xe/0x10 [ 132.613015] [<ffffffff811388ac>] put_css_set+0x5c/0x60 [ 132.613016] [<ffffffff8113dc7f>] cgroup_free+0x7f/0xa0 [ 132.613017] [<ffffffff810a3912>] __put_task_struct+0x42/0x140 [ 132.613018] [<ffffffff810e776a>] dl_task_timer+0xca/0x250 [ 132.613027] [<ffffffff810e76a0>] ? push_dl_task.part.32+0x170/0x170 [ 132.613030] [<ffffffff8111371e>] __hrtimer_run_queues+0xee/0x270 [ 132.613031] [<ffffffff81113ec8>] hrtimer_interrupt+0xa8/0x190 [ 132.613034] [<ffffffff81051a58>] local_apic_timer_interrupt+0x38/0x60 [ 132.613035] [<ffffffff817d9b0d>] smp_apic_timer_interrupt+0x3d/0x50 [ 132.613037] [<ffffffff817d7c5c>] apic_timer_interrupt+0x8c/0xa0 [ 132.613038] <EOI> [<ffffffff81063466>] ? native_safe_halt+0x6/0x10 [ 132.613043] [<ffffffff81037a4e>] default_idle+0x1e/0xd0 [ 132.613044] [<ffffffff810381cf>] arch_cpu_idle+0xf/0x20 [ 132.613046] [<ffffffff810e8fda>] default_idle_call+0x2a/0x40 [ 132.613047] [<ffffffff810e92d7>] cpu_startup_entry+0x2e7/0x340 [ 132.613048] [<ffffffff81050235>] start_secondary+0x155/0x190 [ 132.613049] ---[ end trace f91934d162ce9977 ]--- The warn is the spin_(lock|unlock)_bh(&css_set_lock) in the interrupt context. Converting the spin_lock_bh to spin_lock_irq(save) to avoid this problem - and other problems of sharing a spinlock with an interrupt. Change-Id: I5b5d5c79c3f380ac35f58596fc2cebaf6348eb67 Cc: Tejun Heo <tj@kernel.org> Cc: Li Zefan <lizefan@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: cgroups@vger.kernel.org Cc: stable@vger.kernel.org # 4.5+ Cc: linux-kernel@vger.kernel.org Reviewed-by: Rik van Riel <riel@redhat.com> Reviewed-by: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com> Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com> Acked-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
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This patch fixes the following warning:
[ 2.226264] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:620
[ 2.226341] in_atomic(): 0, irqs_disabled(): 0, pid: 1, name: swapper/0
[ 2.226366] 4 locks held by swapper/0/1:
[ 2.226385] #0: (&dev->mutex){......}, at: [<ffffff800851c664>] __device_attach+0x3c/0x134
[ 2.226515] #1: (cpu_hotplug.lock){......}, at: [<ffffff800809feb0>] get_online_cpus+0x38/0x9c
[ 2.226594] #2: (subsys mutex#7){......}, at: [<ffffff800851b0e4>] subsys_interface_register+0x54/0xfc
[ 2.226684] #3: (rcu_read_lock){......}, at: [<ffffff800845c764>] rockchip_adjust_power_scale+0x88/0x450
[ 2.226771] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 4.4.132 #600
[ 2.226790] Hardware name: Rockchip PX30 evb ddr3 board (DT)
[ 2.226809] Call trace:
[ 2.226840] [<ffffff800808a0d4>] dump_backtrace+0x0/0x1ec
[ 2.226889] [<ffffff800808a2d4>] show_stack+0x14/0x1c
[ 2.226918] [<ffffff80083c41b4>] dump_stack+0x94/0xbc
[ 2.226946] [<ffffff80080cb708>] ___might_sleep+0x108/0x118
[ 2.226972] [<ffffff80080cb788>] __might_sleep+0x70/0x80
[ 2.227001] [<ffffff8008b6d1d0>] mutex_lock_nested+0x54/0x38c
[ 2.227031] [<ffffff8008858714>] __of_clk_get_from_provider+0x44/0xec
[ 2.227061] [<ffffff8008852814>] __of_clk_get_by_name+0xd4/0x14c
[ 2.227112] [<ffffff80088528a4>] of_clk_get_by_name+0x18/0x28
[ 2.227140] [<ffffff800845c980>] rockchip_adjust_power_scale+0x2a4/0x450
[ 2.227171] [<ffffff800877f630>] cpufreq_init+0x154/0x394
[ 2.227199] [<ffffff8008776ac4>] cpufreq_online+0x1b0/0x68c
[ 2.227225] [<ffffff8008777040>] cpufreq_add_dev+0x3c/0x94
[ 2.227253] [<ffffff800851b168>] subsys_interface_register+0xd8/0xfc
[ 2.227281] [<ffffff80087772d8>] cpufreq_register_driver+0x10c/0x1a8
[ 2.227332] [<ffffff800877f93c>] dt_cpufreq_probe+0xcc/0xe8
[ 2.227360] [<ffffff800851e7b8>] platform_drv_probe+0x54/0xa8
[ 2.227385] [<ffffff800851c924>] driver_probe_device+0x194/0x278
[ 2.227411] [<ffffff800851cb40>] __device_attach_driver+0x60/0x9c
[ 2.227439] [<ffffff800851ae14>] bus_for_each_drv+0x9c/0xbc
[ 2.227464] [<ffffff800851c6f0>] __device_attach+0xc8/0x134
[ 2.227488] [<ffffff800851ccb8>] device_initial_probe+0x10/0x18
[ 2.227514] [<ffffff800851bcec>] bus_probe_device+0x2c/0x90
[ 2.227541] [<ffffff8008519e90>] device_add+0x44c/0x510
[ 2.227570] [<ffffff800851e4d4>] platform_device_add+0xa0/0x1e4
[ 2.227597] [<ffffff800851ef28>] platform_device_register_full+0xa4/0xe4
[ 2.227627] [<ffffff80090f8680>] rockchip_cpufreq_driver_init+0xd4/0x31c
[ 2.227654] [<ffffff8008083468>] do_one_initcall+0x84/0x1a4
[ 2.227682] [<ffffff80090c0e98>] kernel_init_freeable+0x260/0x264
[ 2.227708] [<ffffff8008b6ab68>] kernel_init+0x10/0xf8
[ 2.227734] [<ffffff80080832a0>] ret_from_fork+0x10/0x30
Fixes: 197a2d3 ("soc: rockchip: opp_select: add missing rcu lock")
Change-Id: Ib52b6f7bc77bb207a1c8c6880f7a5e916fa3d2ee
Signed-off-by: Finley Xiao <finley.xiao@rock-chips.com>
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commit df30781 upstream. For problem determination we need to see whether and why we were successful or not. This allows deduction of scsi_eh escalation. Example trace record formatted with zfcpdbf from s390-tools: Timestamp : ... Area : SCSI Subarea : 00 Level : 1 Exception : - CPU ID : .. Caller : 0x... Record ID : 1 Tag : schrh_r SCSI host reset handler result Request ID : 0x0000000000000000 none (invalid) SCSI ID : 0xffffffff none (invalid) SCSI LUN : 0xffffffff none (invalid) SCSI LUN high : 0xffffffff none (invalid) SCSI result : 0x00002002 field re-used for midlayer value: SUCCESS or in other cases: 0x2009 == FAST_IO_FAIL SCSI retries : 0xff none (invalid) SCSI allowed : 0xff none (invalid) SCSI scribble : 0xffffffffffffffff none (invalid) SCSI opcode : ffffffff ffffffff ffffffff ffffffff none (invalid) FCP rsp inf cod: 0xff none (invalid) FCP rsp IU : 00000000 00000000 00000000 00000000 none (invalid) 00000000 00000000 v2.6.35 commit a1dbfdd ("[SCSI] zfcp: Pass return code from fc_block_scsi_eh to scsi eh") introduced the first return with something other than the previously hardcoded single SUCCESS return path. Signed-off-by: Steffen Maier <maier@linux.ibm.com> Fixes: a1dbfdd ("[SCSI] zfcp: Pass return code from fc_block_scsi_eh to scsi eh") Cc: <stable@vger.kernel.org> #2.6.38+ Reviewed-by: Jens Remus <jremus@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 81979ae upstream. We already have a SCSI trace for the end of abort and scsi_eh TMF. Due to zfcp_erp_wait() and fc_block_scsi_eh() time can pass between the start of our eh callback and an actual send/recv of an abort / TMF request. In order to see the temporal sequence including any abort / TMF send retries, add a trace before the above two blocking functions. This supports problem determination with scsi_eh and parallel zfcp ERP. No need to explicitly trace the beginning of our eh callback, since we typically can send an abort / TMF and see its HBA response (in the worst case, it's a pseudo response on dismiss all of adapter recovery, e.g. due to an FSF request timeout [fsrth_1] of the abort / TMF). If we cannot send, we now get a trace record for the first "abrt_wt" or "[lt]r_wait" which denotes almost the beginning of the callback. No need to explicitly trace the wakeup after the above two blocking functions because the next retry loop causes another trace in any case and that is sufficient. Example trace records formatted with zfcpdbf from s390-tools: Timestamp : ... Area : SCSI Subarea : 00 Level : 1 Exception : - CPU ID : .. Caller : 0x... Record ID : 1 Tag : abrt_wt abort, before zfcp_erp_wait() Request ID : 0x0000000000000000 none (invalid) SCSI ID : 0x<scsi_id> SCSI LUN : 0x<scsi_lun> SCSI LUN high : 0x<scsi_lun_high> SCSI result : 0x<scsi_result_of_cmd_to_be_aborted> SCSI retries : 0x<retries_of_cmd_to_be_aborted> SCSI allowed : 0x<allowed_retries_of_cmd_to_be_aborted> SCSI scribble : 0x<req_id_of_cmd_to_be_aborted> SCSI opcode : <CDB_of_cmd_to_be_aborted> FCP rsp inf cod: 0x.. none (invalid) FCP rsp IU : ... none (invalid) Timestamp : ... Area : SCSI Subarea : 00 Level : 1 Exception : - CPU ID : .. Caller : 0x... Record ID : 1 Tag : lr_wait LUN reset, before zfcp_erp_wait() Request ID : 0x0000000000000000 none (invalid) SCSI ID : 0x<scsi_id> SCSI LUN : 0x<scsi_lun> SCSI LUN high : 0x<scsi_lun_high> SCSI result : 0x... unrelated SCSI retries : 0x.. unrelated SCSI allowed : 0x.. unrelated SCSI scribble : 0x... unrelated SCSI opcode : ... unrelated FCP rsp inf cod: 0x.. none (invalid) FCP rsp IU : ... none (invalid) Signed-off-by: Steffen Maier <maier@linux.ibm.com> Fixes: 63caf36 ("[SCSI] zfcp: Improve reliability of SCSI eh handlers in zfcp") Fixes: af4de36 ("[SCSI] zfcp: Block scsi_eh thread for rport state BLOCKED") Cc: <stable@vger.kernel.org> #2.6.38+ Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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…ailed commit 512857a upstream. If a SCSI device is deleted during scsi_eh host reset, we cannot get a reference to the SCSI device anymore since scsi_device_get returns !=0 by design. Assuming the recovery of adapter and port(s) was successful, zfcp_erp_strategy_followup_success() attempts to trigger a LUN reset for the half-gone SCSI device. Unfortunately, it causes the following confusing trace record which states that zfcp will do a LUN recovery as "ERP need" is ZFCP_ERP_ACTION_REOPEN_LUN == 1 and equals "ERP want". Old example trace record formatted with zfcpdbf from s390-tools: Tag: : ersfs_3 ERP, trigger, unit reopen, port reopen succeeded LUN : 0x<FCP_LUN> WWPN : 0x<WWPN> D_ID : 0x<N_Port-ID> Adapter status : 0x5400050b Port status : 0x54000001 LUN status : 0x40000000 ZFCP_STATUS_COMMON_RUNNING but not ZFCP_STATUS_COMMON_UNBLOCKED as it was closed on close part of adapter reopen ERP want : 0x01 ERP need : 0x01 misleading However, zfcp_erp_setup_act() returns NULL as it cannot get the reference. Hence, zfcp_erp_action_enqueue() takes an early goto out and _NO_ recovery actually happens. We always do want the recovery trigger trace record even if no erp_action could be enqueued as in this case. For other cases where we did not enqueue an erp_action, 'need' has always been zero to indicate this. In order to indicate above goto out, introduce an eyecatcher "flag" to mark the "ERP need" as 'not needed' but still keep the information which erp_action type, that zfcp_erp_required_act() had decided upon, is needed. 0xc_ is chosen to be visibly different from 0x0_ in "ERP want". New example trace record formatted with zfcpdbf from s390-tools: Tag: : ersfs_3 ERP, trigger, unit reopen, port reopen succeeded LUN : 0x<FCP_LUN> WWPN : 0x<WWPN> D_ID : 0x<N_Port-ID> Adapter status : 0x5400050b Port status : 0x54000001 LUN status : 0x40000000 ERP want : 0x01 ERP need : 0xc1 would need LUN ERP, but no action set up ^ Before v2.6.38 commit ae0904f ("[SCSI] zfcp: Redesign of the debug tracing for recovery actions.") we could detect this case because the "erp_action" field in the trace was NULL. The rework removed erp_action as argument and field from the trace. This patch here is for tracing. A fix to allow LUN recovery in the case at hand is a topic for a separate patch. See also commit fdbd1c5 ("[SCSI] zfcp: Allow running unit/LUN shutdown without acquiring reference") for a similar case and background info. Signed-off-by: Steffen Maier <maier@linux.ibm.com> Fixes: ae0904f ("[SCSI] zfcp: Redesign of the debug tracing for recovery actions.") Cc: <stable@vger.kernel.org> #2.6.38+ Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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… return commit 96d9270 upstream. get_device() and its internally used kobject_get() only return NULL if they get passed NULL as argument. zfcp_get_port_by_wwpn() loops over adapter->port_list so the iteration variable port is always non-NULL. Struct device is embedded in struct zfcp_port so &port->dev is always non-NULL. This is the argument to get_device(). However, if we get an fc_rport in terminate_rport_io() for which we cannot find a match within zfcp_get_port_by_wwpn(), the latter can return NULL. v2.6.30 commit 7093293 ("[SCSI] zfcp: Fix oops when port disappears") introduced an early return without adding a trace record for this case. Even if we don't need recovery in this case, for debugging we should still see that our callback was invoked originally by scsi_transport_fc. Example trace record formatted with zfcpdbf from s390-tools: Timestamp : ... Area : REC Subarea : 00 Level : 1 Exception : - CPU ID : .. Caller : 0x... Record ID : 1 Tag : sctrpin SCSI terminate rport I/O, no zfcp port LUN : 0xffffffffffffffff none (invalid) WWPN : 0x<wwpn> WWPN D_ID : 0x<n_port_id> N_Port-ID Adapter status : 0x... Port status : 0xffffffff unknown (-1) LUN status : 0x00000000 none (invalid) Ready count : 0x... Running count : 0x... ERP want : 0x03 ZFCP_ERP_ACTION_REOPEN_PORT_FORCED ERP need : 0xc0 ZFCP_ERP_ACTION_NONE Signed-off-by: Steffen Maier <maier@linux.ibm.com> Fixes: 7093293 ("[SCSI] zfcp: Fix oops when port disappears") Cc: <stable@vger.kernel.org> #2.6.38+ Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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…RP_FAILED commit d70aab5 upstream. For problem determination we always want to see when we were invoked on the terminate_rport_io callback whether we perform something or not. Temporal event sequence of interest with a long fast_io_fail_tmo of 27 sec: loose remote port t workqueue [s] zfcp_q_<dev> IRQ zfcperp<dev> === ================== =================== ============================ 0 recv RSCN q p.test_link_work block rport start fast_io_fail_tmo send ADISC ELS 4 recv ADISC fail block zfcp_port port forced reopen send open port 12 recv open port fail q p.gid_pn_work zfcp_erp_wakeup (zfcp_erp_wait would return) GID_PN fail Before this point, we got a SCSI trace with tag "sctrpi1" on fast_io_fail, e.g. with the typical 5 sec setting. port.status |= ERP_FAILED If fast_io_fail_tmo triggers after this point, we missed a SCSI trace. workqueue fc_dl_<host> ================== 27 fc_timeout_fail_rport_io fc_terminate_rport_io zfcp_scsi_terminate_rport_io zfcp_erp_port_forced_reopen _zfcp_erp_port_forced_reopen if (port.status & ERP_FAILED) return; Therefore, write a trace before above early return. Example trace record formatted with zfcpdbf from s390-tools: Timestamp : ... Area : REC Subarea : 00 Level : 1 Exception : - CPU ID : .. Caller : 0x... Record ID : 1 ZFCP_DBF_REC_TRIG Tag : sctrpi1 SCSI terminate rport I/O LUN : 0xffffffffffffffff none (invalid) WWPN : 0x<wwpn> D_ID : 0x<n_port_id> Adapter status : 0x... Port status : 0x... LUN status : 0x00000000 none (invalid) Ready count : 0x... Running count : 0x... ERP want : 0x03 ZFCP_ERP_ACTION_REOPEN_PORT_FORCED ERP need : 0xe0 ZFCP_ERP_ACTION_FAILED Signed-off-by: Steffen Maier <maier@linux.ibm.com> Cc: <stable@vger.kernel.org> #2.6.38+ Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 8c3d20a upstream. That other commit introduced an inconsistency because it would trace on ERP_FAILED for all callers of port forced reopen triggers (not just terminate_rport_io), but it would not trace on ERP_FAILED for all callers of other ERP triggers such as adapter, port regular, LUN. Therefore, generalize that other commit. zfcp_erp_action_enqueue() already had two early outs which re-used the one zfcp_dbf_rec_trig() call. All ERP trigger functions finally run through zfcp_erp_action_enqueue(). So move the special handling for ZFCP_STATUS_COMMON_ERP_FAILED into zfcp_erp_action_enqueue() and add another early out with new trace marker for pseudo ERP need in this case. This removes all early returns from all ERP trigger functions so we always end up at zfcp_dbf_rec_trig(). Example trace record formatted with zfcpdbf from s390-tools: Timestamp : ... Area : REC Subarea : 00 Level : 1 Exception : - CPU ID : .. Caller : 0x... Record ID : 1 ZFCP_DBF_REC_TRIG Tag : ....... LUN : 0x... WWPN : 0x... D_ID : 0x... Adapter status : 0x... Port status : 0x... LUN status : 0x... Ready count : 0x... Running count : 0x... ERP want : 0x0. ZFCP_ERP_ACTION_REOPEN_... ERP need : 0xe0 ZFCP_ERP_ACTION_FAILED Signed-off-by: Steffen Maier <maier@linux.ibm.com> Cc: <stable@vger.kernel.org> #2.6.38+ Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 6a76550 upstream. Example trace record formatted with zfcpdbf from s390-tools: Timestamp : ... Area : REC Subarea : 00 Level : 1 Exception : - CPU ID : .. Caller : 0x... Record ID : 1 ZFCP_DBF_REC_TRIG Tag : ....... LUN : 0x... WWPN : 0x... D_ID : 0x... Adapter status : 0x... Port status : 0x... LUN status : 0x... Ready count : 0x... Running count : 0x... ERP want : 0x0. ZFCP_ERP_ACTION_REOPEN_... ERP need : 0xc0 ZFCP_ERP_ACTION_NONE Signed-off-by: Steffen Maier <maier@linux.ibm.com> Cc: <stable@vger.kernel.org> #2.6.38+ Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit b63e132 upstream. The current MIPS implementation of arch_trigger_cpumask_backtrace() is broken because it attempts to use synchronous IPIs despite the fact that it may be run with interrupts disabled. This means that when arch_trigger_cpumask_backtrace() is invoked, for example by the RCU CPU stall watchdog, we may: - Deadlock due to use of synchronous IPIs with interrupts disabled, causing the CPU that's attempting to generate the backtrace output to hang itself. - Not succeed in generating the desired output from remote CPUs. - Produce warnings about this from smp_call_function_many(), for example: [42760.526910] INFO: rcu_sched detected stalls on CPUs/tasks: [42760.535755] 0-...!: (1 GPs behind) idle=ade/140000000000000/0 softirq=526944/526945 fqs=0 [42760.547874] 1-...!: (0 ticks this GP) idle=e4a/140000000000000/0 softirq=547885/547885 fqs=0 [42760.559869] (detected by 2, t=2162 jiffies, g=266689, c=266688, q=33) [42760.568927] ------------[ cut here ]------------ [42760.576146] WARNING: CPU: 2 PID: 1216 at kernel/smp.c:416 smp_call_function_many+0x88/0x20c [42760.587839] Modules linked in: [42760.593152] CPU: 2 PID: 1216 Comm: sh Not tainted 4.15.4-00373-gee058bb4d0c2 #2 [42760.603767] Stack : 8e09bd20 8e09bd20 8e09bd20 fffffff0 00000007 00000006 00000000 8e09bca8 [42760.616937] 95b2b379 95b2b379 807a0080 00000007 81944518 0000018a 00000032 00000000 [42760.630095] 00000000 00000030 80000000 00000000 806eca74 00000009 8017e2b8 000001a0 [42760.643169] 00000000 00000002 00000000 8e09baa4 00000008 808b8008 86d69080 8e09bca0 [42760.656282] 8e09ad50 805e20aa 00000000 00000000 00000000 8017e2b8 00000009 801070ca [42760.669424] ... [42760.673919] Call Trace: [42760.678672] [<27fde568>] show_stack+0x70/0xf0 [42760.685417] [<84751641>] dump_stack+0xaa/0xd0 [42760.692188] [<699d671c>] __warn+0x80/0x92 [42760.698549] [<68915d41>] warn_slowpath_null+0x28/0x36 [42760.705912] [<f7c76c1c>] smp_call_function_many+0x88/0x20c [42760.713696] [<6bbdfc2a>] arch_trigger_cpumask_backtrace+0x30/0x4a [42760.722216] [<f845bd33>] rcu_dump_cpu_stacks+0x6a/0x98 [42760.729580] [<796e7629>] rcu_check_callbacks+0x672/0x6ac [42760.737476] [<059b3b43>] update_process_times+0x18/0x34 [42760.744981] [<6eb94941>] tick_sched_handle.isra.5+0x26/0x38 [42760.752793] [<478d3d70>] tick_sched_timer+0x1c/0x50 [42760.759882] [<e56ea39f>] __hrtimer_run_queues+0xc6/0x226 [42760.767418] [<e88bbcae>] hrtimer_interrupt+0x88/0x19a [42760.775031] [<6765a19e>] gic_compare_interrupt+0x2e/0x3a [42760.782761] [<0558bf5f>] handle_percpu_devid_irq+0x78/0x168 [42760.790795] [<90c11ba2>] generic_handle_irq+0x1e/0x2c [42760.798117] [<1b6d462c>] gic_handle_local_int+0x38/0x86 [42760.805545] [<b2ada1c7>] gic_irq_dispatch+0xa/0x14 [42760.812534] [<90c11ba2>] generic_handle_irq+0x1e/0x2c [42760.820086] [<c7521934>] do_IRQ+0x16/0x20 [42760.826274] [<9aef3ce6>] plat_irq_dispatch+0x62/0x94 [42760.833458] [<6a94b53c>] except_vec_vi_end+0x70/0x78 [42760.840655] [<22284043>] smp_call_function_many+0x1ba/0x20c [42760.848501] [<54022b58>] smp_call_function+0x1e/0x2c [42760.855693] [<ab9fc705>] flush_tlb_mm+0x2a/0x98 [42760.862730] [<0844cdd0>] tlb_flush_mmu+0x1c/0x44 [42760.869628] [<cb259b74>] arch_tlb_finish_mmu+0x26/0x3e [42760.877021] [<1aeaaf74>] tlb_finish_mmu+0x18/0x66 [42760.883907] [<b3fce717>] exit_mmap+0x76/0xea [42760.890428] [<c4c8a2f6>] mmput+0x80/0x11a [42760.896632] [<a41a08f4>] do_exit+0x1f4/0x80c [42760.903158] [<ee01cef6>] do_group_exit+0x20/0x7e [42760.909990] [<13fa8d54>] __wake_up_parent+0x0/0x1e [42760.917045] [<46cf89d0>] smp_call_function_many+0x1a2/0x20c [42760.924893] [<8c21a93b>] syscall_common+0x14/0x1c [42760.931765] ---[ end trace 02aa09da9dc52a60 ]--- [42760.938342] ------------[ cut here ]------------ [42760.945311] WARNING: CPU: 2 PID: 1216 at kernel/smp.c:291 smp_call_function_single+0xee/0xf8 ... This patch switches MIPS' arch_trigger_cpumask_backtrace() to use async IPIs & smp_call_function_single_async() in order to resolve this problem. We ensure use of the pre-allocated call_single_data_t structures is serialized by maintaining a cpumask indicating that they're busy, and refusing to attempt to send an IPI when a CPU's bit is set in this mask. This should only happen if a CPU hasn't responded to a previous backtrace IPI - ie. if it's hung - and we print a warning to the console in this case. I've marked this for stable branches as far back as v4.9, to which it applies cleanly. Strictly speaking the faulty MIPS implementation can be traced further back to commit 856839b ("MIPS: Add arch_trigger_all_cpu_backtrace() function") in v3.19, but kernel versions v3.19 through v4.8 will require further work to backport due to the rework performed in commit 9a01c3e ("nmi_backtrace: add more trigger_*_cpu_backtrace() methods"). Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/19597/ Cc: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Huacai Chen <chenhc@lemote.com> Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org # v4.9+ Fixes: 856839b ("MIPS: Add arch_trigger_all_cpu_backtrace() function") Fixes: 9a01c3e ("nmi_backtrace: add more trigger_*_cpu_backtrace() methods") [ Huacai: backported to 4.4: Restruction since generic NMI solution is unavailable ] Signed-off-by: Huacai Chen <chenhc@lemote.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit c604cb7 upstream. My recent fix for dns_resolver_preparse() printing very long strings was incomplete, as shown by syzbot which still managed to hit the WARN_ONCE() in set_precision() by adding a crafted "dns_resolver" key: precision 50001 too large WARNING: CPU: 7 PID: 864 at lib/vsprintf.c:2164 vsnprintf+0x48a/0x5a0 The bug this time isn't just a printing bug, but also a logical error when multiple options ("#"-separated strings) are given in the key payload. Specifically, when separating an option string into name and value, if there is no value then the name is incorrectly considered to end at the end of the key payload, rather than the end of the current option. This bypasses validation of the option length, and also means that specifying multiple options is broken -- which presumably has gone unnoticed as there is currently only one valid option anyway. A similar problem also applied to option values, as the kstrtoul() when parsing the "dnserror" option will read past the end of the current option and into the next option. Fix these bugs by correctly computing the length of the option name and by copying the option value, null-terminated, into a temporary buffer. Reproducer for the WARN_ONCE() that syzbot hit: perl -e 'print "#A#", "\0" x 50000' | keyctl padd dns_resolver desc @s Reproducer for "dnserror" option being parsed incorrectly (expected behavior is to fail when seeing the unknown option "foo", actual behavior was to read the dnserror value as "1#foo" and fail there): perl -e 'print "#dnserror=1#foo\0"' | keyctl padd dns_resolver desc @s Reported-by: syzbot <syzkaller@googlegroups.com> Fixes: 4a2d789 ("DNS: If the DNS server returns an error, allow that to be cached [ver #2]") Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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This patch fixes the following warning:
[ 2.226264] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:620
[ 2.226341] in_atomic(): 0, irqs_disabled(): 0, pid: 1, name: swapper/0
[ 2.226366] 4 locks held by swapper/0/1:
[ 2.226385] #0: (&dev->mutex){......}, at: [<ffffff800851c664>] __device_attach+0x3c/0x134
[ 2.226515] #1: (cpu_hotplug.lock){......}, at: [<ffffff800809feb0>] get_online_cpus+0x38/0x9c
[ 2.226594] #2: (subsys mutex#7){......}, at: [<ffffff800851b0e4>] subsys_interface_register+0x54/0xfc
[ 2.226684] #3: (rcu_read_lock){......}, at: [<ffffff800845c764>] rockchip_adjust_power_scale+0x88/0x450
[ 2.226771] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 4.4.132 #600
[ 2.226790] Hardware name: Rockchip PX30 evb ddr3 board (DT)
[ 2.226809] Call trace:
[ 2.226840] [<ffffff800808a0d4>] dump_backtrace+0x0/0x1ec
[ 2.226889] [<ffffff800808a2d4>] show_stack+0x14/0x1c
[ 2.226918] [<ffffff80083c41b4>] dump_stack+0x94/0xbc
[ 2.226946] [<ffffff80080cb708>] ___might_sleep+0x108/0x118
[ 2.226972] [<ffffff80080cb788>] __might_sleep+0x70/0x80
[ 2.227001] [<ffffff8008b6d1d0>] mutex_lock_nested+0x54/0x38c
[ 2.227031] [<ffffff8008858714>] __of_clk_get_from_provider+0x44/0xec
[ 2.227061] [<ffffff8008852814>] __of_clk_get_by_name+0xd4/0x14c
[ 2.227112] [<ffffff80088528a4>] of_clk_get_by_name+0x18/0x28
[ 2.227140] [<ffffff800845c980>] rockchip_adjust_power_scale+0x2a4/0x450
[ 2.227171] [<ffffff800877f630>] cpufreq_init+0x154/0x394
[ 2.227199] [<ffffff8008776ac4>] cpufreq_online+0x1b0/0x68c
[ 2.227225] [<ffffff8008777040>] cpufreq_add_dev+0x3c/0x94
[ 2.227253] [<ffffff800851b168>] subsys_interface_register+0xd8/0xfc
[ 2.227281] [<ffffff80087772d8>] cpufreq_register_driver+0x10c/0x1a8
[ 2.227332] [<ffffff800877f93c>] dt_cpufreq_probe+0xcc/0xe8
[ 2.227360] [<ffffff800851e7b8>] platform_drv_probe+0x54/0xa8
[ 2.227385] [<ffffff800851c924>] driver_probe_device+0x194/0x278
[ 2.227411] [<ffffff800851cb40>] __device_attach_driver+0x60/0x9c
[ 2.227439] [<ffffff800851ae14>] bus_for_each_drv+0x9c/0xbc
[ 2.227464] [<ffffff800851c6f0>] __device_attach+0xc8/0x134
[ 2.227488] [<ffffff800851ccb8>] device_initial_probe+0x10/0x18
[ 2.227514] [<ffffff800851bcec>] bus_probe_device+0x2c/0x90
[ 2.227541] [<ffffff8008519e90>] device_add+0x44c/0x510
[ 2.227570] [<ffffff800851e4d4>] platform_device_add+0xa0/0x1e4
[ 2.227597] [<ffffff800851ef28>] platform_device_register_full+0xa4/0xe4
[ 2.227627] [<ffffff80090f8680>] rockchip_cpufreq_driver_init+0xd4/0x31c
[ 2.227654] [<ffffff8008083468>] do_one_initcall+0x84/0x1a4
[ 2.227682] [<ffffff80090c0e98>] kernel_init_freeable+0x260/0x264
[ 2.227708] [<ffffff8008b6ab68>] kernel_init+0x10/0xf8
[ 2.227734] [<ffffff80080832a0>] ret_from_fork+0x10/0x30
Fixes: 197a2d3 ("soc: rockchip: opp_select: add missing rcu lock")
Change-Id: Ib52b6f7bc77bb207a1c8c6880f7a5e916fa3d2ee
Signed-off-by: Finley Xiao <finley.xiao@rock-chips.com>
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While testing the deadline scheduler + cgroup setup I hit this warning. [ 132.612935] ------------[ cut here ]------------ [ 132.612951] WARNING: CPU: 5 PID: 0 at kernel/softirq.c:150 __local_bh_enable_ip+0x6b/0x80 [ 132.612952] Modules linked in: (a ton of modules...) [ 132.612981] CPU: 5 PID: 0 Comm: swapper/5 Not tainted 4.7.0-rc2 #2 [ 132.612981] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.2-20150714_191134- 04/01/2014 [ 132.612982] 0000000000000086 45c8bb5effdd088b ffff88013fd43da0 ffffffff813d229e [ 132.612984] 0000000000000000 0000000000000000 ffff88013fd43de0 ffffffff810a652b [ 132.612985] 00000096811387b5 0000000000000200 ffff8800bab29d80 ffff880034c54c00 [ 132.612986] Call Trace: [ 132.612987] <IRQ> [<ffffffff813d229e>] dump_stack+0x63/0x85 [ 132.612994] [<ffffffff810a652b>] __warn+0xcb/0xf0 [ 132.612997] [<ffffffff810e76a0>] ? push_dl_task.part.32+0x170/0x170 [ 132.612999] [<ffffffff810a665d>] warn_slowpath_null+0x1d/0x20 [ 132.613000] [<ffffffff810aba5b>] __local_bh_enable_ip+0x6b/0x80 [ 132.613008] [<ffffffff817d6c8a>] _raw_write_unlock_bh+0x1a/0x20 [ 132.613010] [<ffffffff817d6c9e>] _raw_spin_unlock_bh+0xe/0x10 [ 132.613015] [<ffffffff811388ac>] put_css_set+0x5c/0x60 [ 132.613016] [<ffffffff8113dc7f>] cgroup_free+0x7f/0xa0 [ 132.613017] [<ffffffff810a3912>] __put_task_struct+0x42/0x140 [ 132.613018] [<ffffffff810e776a>] dl_task_timer+0xca/0x250 [ 132.613027] [<ffffffff810e76a0>] ? push_dl_task.part.32+0x170/0x170 [ 132.613030] [<ffffffff8111371e>] __hrtimer_run_queues+0xee/0x270 [ 132.613031] [<ffffffff81113ec8>] hrtimer_interrupt+0xa8/0x190 [ 132.613034] [<ffffffff81051a58>] local_apic_timer_interrupt+0x38/0x60 [ 132.613035] [<ffffffff817d9b0d>] smp_apic_timer_interrupt+0x3d/0x50 [ 132.613037] [<ffffffff817d7c5c>] apic_timer_interrupt+0x8c/0xa0 [ 132.613038] <EOI> [<ffffffff81063466>] ? native_safe_halt+0x6/0x10 [ 132.613043] [<ffffffff81037a4e>] default_idle+0x1e/0xd0 [ 132.613044] [<ffffffff810381cf>] arch_cpu_idle+0xf/0x20 [ 132.613046] [<ffffffff810e8fda>] default_idle_call+0x2a/0x40 [ 132.613047] [<ffffffff810e92d7>] cpu_startup_entry+0x2e7/0x340 [ 132.613048] [<ffffffff81050235>] start_secondary+0x155/0x190 [ 132.613049] ---[ end trace f91934d162ce9977 ]--- The warn is the spin_(lock|unlock)_bh(&css_set_lock) in the interrupt context. Converting the spin_lock_bh to spin_lock_irq(save) to avoid this problem - and other problems of sharing a spinlock with an interrupt. Change-Id: I5b5d5c79c3f380ac35f58596fc2cebaf6348eb67 Cc: Tejun Heo <tj@kernel.org> Cc: Li Zefan <lizefan@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: cgroups@vger.kernel.org Cc: stable@vger.kernel.org # 4.5+ Cc: linux-kernel@vger.kernel.org Reviewed-by: Rik van Riel <riel@redhat.com> Reviewed-by: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com> Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com> Acked-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
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[ Upstream commit fba9eb7 ] Add a header with macros usable in assembler files to emit alternative code sequences. It works analog to the alternatives for inline assmeblies in C files, with the same restrictions and capabilities. The syntax is ALTERNATIVE "<default instructions sequence>", \ "<alternative instructions sequence>", \ "<features-bit>" and ALTERNATIVE_2 "<default instructions sequence>", \ "<alternative instructions sqeuence #1>", \ "<feature-bit #1>", "<alternative instructions sqeuence #2>", \ "<feature-bit #2>" Reviewed-by: Vasily Gorbik <gor@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 2c0aa08 ] Scenario: 1. Port down and do fail over 2. Ap do rds_bind syscall PID: 47039 TASK: ffff89887e2fe640 CPU: 47 COMMAND: "kworker/u:6" #0 [ffff898e35f159f0] machine_kexec at ffffffff8103abf9 #1 [ffff898e35f15a60] crash_kexec at ffffffff810b96e3 #2 [ffff898e35f15b30] oops_end at ffffffff8150f518 #3 [ffff898e35f15b60] no_context at ffffffff8104854c #4 [ffff898e35f15ba0] __bad_area_nosemaphore at ffffffff81048675 khadas#5 [ffff898e35f15bf0] bad_area_nosemaphore at ffffffff810487d3 khadas#6 [ffff898e35f15c00] do_page_fault at ffffffff815120b8 khadas#7 [ffff898e35f15d10] page_fault at ffffffff8150ea95 [exception RIP: unknown or invalid address] RIP: 0000000000000000 RSP: ffff898e35f15dc8 RFLAGS: 00010282 RAX: 00000000fffffffe RBX: ffff889b77f6fc00 RCX:ffffffff81c99d88 RDX: 0000000000000000 RSI: ffff896019ee08e8 RDI:ffff889b77f6fc00 RBP: ffff898e35f15df0 R8: ffff896019ee08c8 R9:0000000000000000 R10: 0000000000000400 R11: 0000000000000000 R12:ffff896019ee08c0 R13: ffff889b77f6fe68 R14: ffffffff81c99d80 R15: ffffffffa022a1e0 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 khadas#8 [ffff898e35f15dc8] cma_ndev_work_handler at ffffffffa022a228 [rdma_cm] khadas#9 [ffff898e35f15df8] process_one_work at ffffffff8108a7c6 khadas#10 [ffff898e35f15e58] worker_thread at ffffffff8108bda0 khadas#11 [ffff898e35f15ee8] kthread at ffffffff81090fe6 PID: 45659 TASK: ffff880d313d2500 CPU: 31 COMMAND: "oracle_45659_ap" #0 [ffff881024ccfc98] __schedule at ffffffff8150bac4 #1 [ffff881024ccfd40] schedule at ffffffff8150c2cf #2 [ffff881024ccfd50] __mutex_lock_slowpath at ffffffff8150cee7 #3 [ffff881024ccfdc0] mutex_lock at ffffffff8150cdeb #4 [ffff881024ccfde0] rdma_destroy_id at ffffffffa022a027 [rdma_cm] khadas#5 [ffff881024ccfe10] rds_ib_laddr_check at ffffffffa0357857 [rds_rdma] khadas#6 [ffff881024ccfe50] rds_trans_get_preferred at ffffffffa0324c2a [rds] khadas#7 [ffff881024ccfe80] rds_bind at ffffffffa031d690 [rds] khadas#8 [ffff881024ccfeb0] sys_bind at ffffffff8142a670 PID: 45659 PID: 47039 rds_ib_laddr_check /* create id_priv with a null event_handler */ rdma_create_id rdma_bind_addr cma_acquire_dev /* add id_priv to cma_dev->id_list */ cma_attach_to_dev cma_ndev_work_handler /* event_hanlder is null */ id_priv->id.event_handler Signed-off-by: Guanglei Li <guanglei.li@oracle.com> Signed-off-by: Honglei Wang <honglei.wang@oracle.com> Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com> Reviewed-by: Yanjun Zhu <yanjun.zhu@oracle.com> Reviewed-by: Leon Romanovsky <leonro@mellanox.com> Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Acked-by: Doug Ledford <dledford@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit b6dd4d8 ] The pr_debug() in gic-v3 gic_send_sgi() can trigger a circular locking warning: GICv3: CPU10: ICC_SGI1R_EL1 5000400 ====================================================== WARNING: possible circular locking dependency detected 4.15.0+ #1 Tainted: G W ------------------------------------------------------ dynamic_debug01/1873 is trying to acquire lock: ((console_sem).lock){-...}, at: [<0000000099c891ec>] down_trylock+0x20/0x4c but task is already holding lock: (&rq->lock){-.-.}, at: [<00000000842e1587>] __task_rq_lock+0x54/0xdc which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&rq->lock){-.-.}: __lock_acquire+0x3b4/0x6e0 lock_acquire+0xf4/0x2a8 _raw_spin_lock+0x4c/0x60 task_fork_fair+0x3c/0x148 sched_fork+0x10c/0x214 copy_process.isra.32.part.33+0x4e8/0x14f0 _do_fork+0xe8/0x78c kernel_thread+0x48/0x54 rest_init+0x34/0x2a4 start_kernel+0x45c/0x488 -> #1 (&p->pi_lock){-.-.}: __lock_acquire+0x3b4/0x6e0 lock_acquire+0xf4/0x2a8 _raw_spin_lock_irqsave+0x58/0x70 try_to_wake_up+0x48/0x600 wake_up_process+0x28/0x34 __up.isra.0+0x60/0x6c up+0x60/0x68 __up_console_sem+0x4c/0x7c console_unlock+0x328/0x634 vprintk_emit+0x25c/0x390 dev_vprintk_emit+0xc4/0x1fc dev_printk_emit+0x88/0xa8 __dev_printk+0x58/0x9c _dev_info+0x84/0xa8 usb_new_device+0x100/0x474 hub_port_connect+0x280/0x92c hub_event+0x740/0xa84 process_one_work+0x240/0x70c worker_thread+0x60/0x400 kthread+0x110/0x13c ret_from_fork+0x10/0x18 -> #0 ((console_sem).lock){-...}: validate_chain.isra.34+0x6e4/0xa20 __lock_acquire+0x3b4/0x6e0 lock_acquire+0xf4/0x2a8 _raw_spin_lock_irqsave+0x58/0x70 down_trylock+0x20/0x4c __down_trylock_console_sem+0x3c/0x9c console_trylock+0x20/0xb0 vprintk_emit+0x254/0x390 vprintk_default+0x58/0x90 vprintk_func+0xbc/0x164 printk+0x80/0xa0 __dynamic_pr_debug+0x84/0xac gic_raise_softirq+0x184/0x18c smp_cross_call+0xac/0x218 smp_send_reschedule+0x3c/0x48 resched_curr+0x60/0x9c check_preempt_curr+0x70/0xdc wake_up_new_task+0x310/0x470 _do_fork+0x188/0x78c SyS_clone+0x44/0x50 __sys_trace_return+0x0/0x4 other info that might help us debug this: Chain exists of: (console_sem).lock --> &p->pi_lock --> &rq->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&rq->lock); lock(&p->pi_lock); lock(&rq->lock); lock((console_sem).lock); *** DEADLOCK *** 2 locks held by dynamic_debug01/1873: #0: (&p->pi_lock){-.-.}, at: [<000000001366df53>] wake_up_new_task+0x40/0x470 #1: (&rq->lock){-.-.}, at: [<00000000842e1587>] __task_rq_lock+0x54/0xdc stack backtrace: CPU: 10 PID: 1873 Comm: dynamic_debug01 Tainted: G W 4.15.0+ #1 Hardware name: GIGABYTE R120-T34-00/MT30-GS2-00, BIOS T48 10/02/2017 Call trace: dump_backtrace+0x0/0x188 show_stack+0x24/0x2c dump_stack+0xa4/0xe0 print_circular_bug.isra.31+0x29c/0x2b8 check_prev_add.constprop.39+0x6c8/0x6dc validate_chain.isra.34+0x6e4/0xa20 __lock_acquire+0x3b4/0x6e0 lock_acquire+0xf4/0x2a8 _raw_spin_lock_irqsave+0x58/0x70 down_trylock+0x20/0x4c __down_trylock_console_sem+0x3c/0x9c console_trylock+0x20/0xb0 vprintk_emit+0x254/0x390 vprintk_default+0x58/0x90 vprintk_func+0xbc/0x164 printk+0x80/0xa0 __dynamic_pr_debug+0x84/0xac gic_raise_softirq+0x184/0x18c smp_cross_call+0xac/0x218 smp_send_reschedule+0x3c/0x48 resched_curr+0x60/0x9c check_preempt_curr+0x70/0xdc wake_up_new_task+0x310/0x470 _do_fork+0x188/0x78c SyS_clone+0x44/0x50 __sys_trace_return+0x0/0x4 GICv3: CPU0: ICC_SGI1R_EL1 12000 This could be fixed with printk_deferred() but that might lessen its usefulness for debugging. So change it to pr_devel to keep it out of production kernels. Developers working on gic-v3 can enable it as needed in their kernels. Signed-off-by: Mark Salter <msalter@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 2bbea6e ] when mounting an ISO filesystem sometimes (very rarely) the system hangs because of a race condition between two tasks. PID: 6766 TASK: ffff88007b2a6dd0 CPU: 0 COMMAND: "mount" #0 [ffff880078447ae0] __schedule at ffffffff8168d605 #1 [ffff880078447b48] schedule_preempt_disabled at ffffffff8168ed49 #2 [ffff880078447b58] __mutex_lock_slowpath at ffffffff8168c995 #3 [ffff880078447bb8] mutex_lock at ffffffff8168bdef #4 [ffff880078447bd0] sr_block_ioctl at ffffffffa00b6818 [sr_mod] khadas#5 [ffff880078447c10] blkdev_ioctl at ffffffff812fea50 khadas#6 [ffff880078447c70] ioctl_by_bdev at ffffffff8123a8b3 khadas#7 [ffff880078447c90] isofs_fill_super at ffffffffa04fb1e1 [isofs] khadas#8 [ffff880078447da8] mount_bdev at ffffffff81202570 khadas#9 [ffff880078447e18] isofs_mount at ffffffffa04f9828 [isofs] khadas#10 [ffff880078447e28] mount_fs at ffffffff81202d09 khadas#11 [ffff880078447e70] vfs_kern_mount at ffffffff8121ea8f khadas#12 [ffff880078447ea8] do_mount at ffffffff81220fee khadas#13 [ffff880078447f28] sys_mount at ffffffff812218d6 khadas#14 [ffff880078447f80] system_call_fastpath at ffffffff81698c49 RIP: 00007fd9ea914e9a RSP: 00007ffd5d9bf648 RFLAGS: 00010246 RAX: 00000000000000a5 RBX: ffffffff81698c49 RCX: 0000000000000010 RDX: 00007fd9ec2bc210 RSI: 00007fd9ec2bc290 RDI: 00007fd9ec2bcf30 RBP: 0000000000000000 R8: 0000000000000000 R9: 0000000000000010 R10: 00000000c0ed0001 R11: 0000000000000206 R12: 00007fd9ec2bc040 R13: 00007fd9eb6b2380 R14: 00007fd9ec2bc210 R15: 00007fd9ec2bcf30 ORIG_RAX: 00000000000000a5 CS: 0033 SS: 002b This task was trying to mount the cdrom. It allocated and configured a super_block struct and owned the write-lock for the super_block->s_umount rwsem. While exclusively owning the s_umount lock, it called sr_block_ioctl and waited to acquire the global sr_mutex lock. PID: 6785 TASK: ffff880078720fb0 CPU: 0 COMMAND: "systemd-udevd" #0 [ffff880078417898] __schedule at ffffffff8168d605 #1 [ffff880078417900] schedule at ffffffff8168dc59 #2 [ffff880078417910] rwsem_down_read_failed at ffffffff8168f605 #3 [ffff880078417980] call_rwsem_down_read_failed at ffffffff81328838 #4 [ffff8800784179d0] down_read at ffffffff8168cde0 khadas#5 [ffff8800784179e8] get_super at ffffffff81201cc7 khadas#6 [ffff880078417a10] __invalidate_device at ffffffff8123a8de khadas#7 [ffff880078417a40] flush_disk at ffffffff8123a94b khadas#8 [ffff880078417a88] check_disk_change at ffffffff8123ab50 khadas#9 [ffff880078417ab0] cdrom_open at ffffffffa00a29e1 [cdrom] khadas#10 [ffff880078417b68] sr_block_open at ffffffffa00b6f9b [sr_mod] khadas#11 [ffff880078417b98] __blkdev_get at ffffffff8123ba86 khadas#12 [ffff880078417bf0] blkdev_get at ffffffff8123bd65 khadas#13 [ffff880078417c78] blkdev_open at ffffffff8123bf9b khadas#14 [ffff880078417c90] do_dentry_open at ffffffff811fc7f7 khadas#15 [ffff880078417cd8] vfs_open at ffffffff811fc9cf khadas#16 [ffff880078417d00] do_last at ffffffff8120d53d khadas#17 [ffff880078417db0] path_openat at ffffffff8120e6b2 khadas#18 [ffff880078417e48] do_filp_open at ffffffff8121082b khadas#19 [ffff880078417f18] do_sys_open at ffffffff811fdd33 khadas#20 [ffff880078417f70] sys_open at ffffffff811fde4e khadas#21 [ffff880078417f80] system_call_fastpath at ffffffff81698c49 RIP: 00007f29438b0c20 RSP: 00007ffc76624b78 RFLAGS: 00010246 RAX: 0000000000000002 RBX: ffffffff81698c49 RCX: 0000000000000000 RDX: 00007f2944a5fa70 RSI: 00000000000a0800 RDI: 00007f2944a5fa70 RBP: 00007f2944a5f540 R8: 0000000000000000 R9: 0000000000000020 R10: 00007f2943614c40 R11: 0000000000000246 R12: ffffffff811fde4e R13: ffff880078417f78 R14: 000000000000000c R15: 00007f2944a4b010 ORIG_RAX: 0000000000000002 CS: 0033 SS: 002b This task tried to open the cdrom device, the sr_block_open function acquired the global sr_mutex lock. The call to check_disk_change() then saw an event flag indicating a possible media change and tried to flush any cached data for the device. As part of the flush, it tried to acquire the super_block->s_umount lock associated with the cdrom device. This was the same super_block as created and locked by the previous task. The first task acquires the s_umount lock and then the sr_mutex_lock; the second task acquires the sr_mutex_lock and then the s_umount lock. This patch fixes the issue by moving check_disk_change() out of cdrom_open() and let the caller take care of it. Signed-off-by: Maurizio Lombardi <mlombard@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit a3ca831 ] When booting up with "threadirqs" in command line, all irq handlers of the DMA controller pl330 will be threaded forcedly. These threads will race for the same list, pl330->req_done. Before the callback, the spinlock was released. And after it, the spinlock was taken. This opened an race window where another threaded irq handler could steal the spinlock and be permitted to delete entries of the list, pl330->req_done. If the later deleted an entry that was still referred to by the former, there would be a kernel panic when the former was scheduled and tried to get the next sibling of the deleted entry. The scenario could be depicted as below: Thread: T1 pl330->req_done Thread: T2 | | | | -A-B-C-D- | Locked | | | | Waiting Del A | | | -B-C-D- | Unlocked | | | | Locked Waiting | | | | Del B | | | | -C-D- Unlocked Waiting | | | Locked | get C via B \ - Kernel panic The kernel panic looked like as below: Unable to handle kernel paging request at virtual address dead000000000108 pgd = ffffff8008c9e000 [dead000000000108] *pgd=000000027fffe003, *pud=000000027fffe003, *pmd=0000000000000000 Internal error: Oops: 96000044 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 85 Comm: irq/59-66330000 Not tainted 4.8.24-WR9.0.0.12_standard #2 Hardware name: Broadcom NS2 SVK (DT) task: ffffffc1f5cc3c00 task.stack: ffffffc1f5ce0000 PC is at pl330_irq_handler+0x27c/0x390 LR is at pl330_irq_handler+0x2a8/0x390 pc : [<ffffff80084cb694>] lr : [<ffffff80084cb6c0>] pstate: 800001c5 sp : ffffffc1f5ce3d00 x29: ffffffc1f5ce3d00 x28: 0000000000000140 x27: ffffffc1f5c530b0 x26: dead000000000100 x25: dead000000000200 x24: 0000000000418958 x23: 0000000000000001 x22: ffffffc1f5ccd668 x21: ffffffc1f5ccd590 x20: ffffffc1f5ccd418 x19: dead000000000060 x18: 0000000000000001 x17: 0000000000000007 x16: 0000000000000001 x15: ffffffffffffffff x14: ffffffffffffffff x13: ffffffffffffffff x12: 0000000000000000 x11: 0000000000000001 x10: 0000000000000840 x9 : ffffffc1f5ce0000 x8 : ffffffc1f5cc3338 x7 : ffffff8008ce2020 x6 : 0000000000000000 x5 : 0000000000000000 x4 : 0000000000000001 x3 : dead000000000200 x2 : dead000000000100 x1 : 0000000000000140 x0 : ffffffc1f5ccd590 Process irq/59-66330000 (pid: 85, stack limit = 0xffffffc1f5ce0020) Stack: (0xffffffc1f5ce3d00 to 0xffffffc1f5ce4000) 3d00: ffffffc1f5ce3d80 ffffff80080f09d0 ffffffc1f5ca0c00 ffffffc1f6f7c600 3d20: ffffffc1f5ce0000 ffffffc1f6f7c600 ffffffc1f5ca0c00 ffffff80080f0998 3d40: ffffffc1f5ce0000 ffffff80080f0000 0000000000000000 0000000000000000 3d60: ffffff8008ce202c ffffff8008ce2020 ffffffc1f5ccd668 ffffffc1f5c530b0 3d80: ffffffc1f5ce3db0 ffffff80080f0d70 ffffffc1f5ca0c40 0000000000000001 3da0: ffffffc1f5ce0000 ffffff80080f0cfc ffffffc1f5ce3e20 ffffff80080bf4f8 3dc0: ffffffc1f5ca0c80 ffffff8008bf3798 ffffff8008955528 ffffffc1f5ca0c00 3de0: ffffff80080f0c30 0000000000000000 0000000000000000 0000000000000000 3e00: 0000000000000000 0000000000000000 0000000000000000 ffffff80080f0b68 3e20: 0000000000000000 ffffff8008083690 ffffff80080bf420 ffffffc1f5ca0c80 3e40: 0000000000000000 0000000000000000 0000000000000000 ffffff80080cb648 3e60: ffffff8008b1c780 0000000000000000 0000000000000000 ffffffc1f5ca0c00 3e80: ffffffc100000000 ffffff8000000000 ffffffc1f5ce3e90 ffffffc1f5ce3e90 3ea0: 0000000000000000 ffffff8000000000 ffffffc1f5ce3eb0 ffffffc1f5ce3eb0 3ec0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 3ee0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 3f00: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 3f20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 3f40: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 3f60: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 3f80: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 3fa0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 3fc0: 0000000000000000 0000000000000005 0000000000000000 0000000000000000 3fe0: 0000000000000000 0000000000000000 0000000275ce3ff0 0000000275ce3ff8 Call trace: Exception stack(0xffffffc1f5ce3b30 to 0xffffffc1f5ce3c60) 3b20: dead000000000060 0000008000000000 3b40: ffffffc1f5ce3d00 ffffff80084cb694 0000000000000008 0000000000000e88 3b60: ffffffc1f5ce3bb0 ffffff80080dac68 ffffffc1f5ce3b90 ffffff8008826fe4 3b80: 00000000000001c0 00000000000001c0 ffffffc1f5ce3bb0 ffffff800848dfcc 3ba0: 0000000000020000 ffffff8008b15ae4 ffffffc1f5ce3c00 ffffff800808f000 3bc0: 0000000000000010 ffffff80088377f0 ffffffc1f5ccd590 0000000000000140 3be0: dead000000000100 dead000000000200 0000000000000001 0000000000000000 3c00: 0000000000000000 ffffff8008ce2020 ffffffc1f5cc3338 ffffffc1f5ce0000 3c20: 0000000000000840 0000000000000001 0000000000000000 ffffffffffffffff 3c40: ffffffffffffffff ffffffffffffffff 0000000000000001 0000000000000007 [<ffffff80084cb694>] pl330_irq_handler+0x27c/0x390 [<ffffff80080f09d0>] irq_forced_thread_fn+0x38/0x88 [<ffffff80080f0d70>] irq_thread+0x140/0x200 [<ffffff80080bf4f8>] kthread+0xd8/0xf0 [<ffffff8008083690>] ret_from_fork+0x10/0x40 Code: f2a00838 f9405763 aa1c03e1 aa1503e0 (f9000443) ---[ end trace f50005726d31199c ]--- Kernel panic - not syncing: Fatal exception in interrupt SMP: stopping secondary CPUs SMP: failed to stop secondary CPUs 0-1 Kernel Offset: disabled Memory Limit: none ---[ end Kernel panic - not syncing: Fatal exception in interrupt To fix this, re-start with the list-head after dropping the lock then re-takeing it. Reviewed-by: Frank Mori Hess <fmh6jj@gmail.com> Tested-by: Frank Mori Hess <fmh6jj@gmail.com> Signed-off-by: Qi Hou <qi.hou@windriver.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 86968ef ] Calling ceph_buffer_put() in __ceph_setxattr() may end up freeing the i_xattrs.prealloc_blob buffer while holding the i_ceph_lock. This can be fixed by postponing the call until later, when the lock is released. The following backtrace was triggered by fstests generic/117. BUG: sleeping function called from invalid context at mm/vmalloc.c:2283 in_atomic(): 1, irqs_disabled(): 0, pid: 650, name: fsstress 3 locks held by fsstress/650: #0: 00000000870a0fe8 (sb_writers#8){.+.+}, at: mnt_want_write+0x20/0x50 #1: 00000000ba0c4c74 (&type->i_mutex_dir_key#6){++++}, at: vfs_setxattr+0x55/0xa0 #2: 000000008dfbb3f2 (&(&ci->i_ceph_lock)->rlock){+.+.}, at: __ceph_setxattr+0x297/0x810 CPU: 1 PID: 650 Comm: fsstress Not tainted 5.2.0+ #437 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58-prebuilt.qemu.org 04/01/2014 Call Trace: dump_stack+0x67/0x90 ___might_sleep.cold+0x9f/0xb1 vfree+0x4b/0x60 ceph_buffer_release+0x1b/0x60 __ceph_setxattr+0x2b4/0x810 __vfs_setxattr+0x66/0x80 __vfs_setxattr_noperm+0x59/0xf0 vfs_setxattr+0x81/0xa0 setxattr+0x115/0x230 ? filename_lookup+0xc9/0x140 ? rcu_read_lock_sched_held+0x74/0x80 ? rcu_sync_lockdep_assert+0x2e/0x60 ? __sb_start_write+0x142/0x1a0 ? mnt_want_write+0x20/0x50 path_setxattr+0xba/0xd0 __x64_sys_lsetxattr+0x24/0x30 do_syscall_64+0x50/0x1c0 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7ff23514359a Signed-off-by: Luis Henriques <lhenriques@suse.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit af8a85a ] Calling ceph_buffer_put() in fill_inode() may result in freeing the i_xattrs.blob buffer while holding the i_ceph_lock. This can be fixed by postponing the call until later, when the lock is released. The following backtrace was triggered by fstests generic/070. BUG: sleeping function called from invalid context at mm/vmalloc.c:2283 in_atomic(): 1, irqs_disabled(): 0, pid: 3852, name: kworker/0:4 6 locks held by kworker/0:4/3852: #0: 000000004270f6bb ((wq_completion)ceph-msgr){+.+.}, at: process_one_work+0x1b8/0x5f0 #1: 00000000eb420803 ((work_completion)(&(&con->work)->work)){+.+.}, at: process_one_work+0x1b8/0x5f0 #2: 00000000be1c53a4 (&s->s_mutex){+.+.}, at: dispatch+0x288/0x1476 #3: 00000000559cb958 (&mdsc->snap_rwsem){++++}, at: dispatch+0x2eb/0x1476 #4: 000000000d5ebbae (&req->r_fill_mutex){+.+.}, at: dispatch+0x2fc/0x1476 khadas#5: 00000000a83d0514 (&(&ci->i_ceph_lock)->rlock){+.+.}, at: fill_inode.isra.0+0xf8/0xf70 CPU: 0 PID: 3852 Comm: kworker/0:4 Not tainted 5.2.0+ #441 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58-prebuilt.qemu.org 04/01/2014 Workqueue: ceph-msgr ceph_con_workfn Call Trace: dump_stack+0x67/0x90 ___might_sleep.cold+0x9f/0xb1 vfree+0x4b/0x60 ceph_buffer_release+0x1b/0x60 fill_inode.isra.0+0xa9b/0xf70 ceph_fill_trace+0x13b/0xc70 ? dispatch+0x2eb/0x1476 dispatch+0x320/0x1476 ? __mutex_unlock_slowpath+0x4d/0x2a0 ceph_con_workfn+0xc97/0x2ec0 ? process_one_work+0x1b8/0x5f0 process_one_work+0x244/0x5f0 worker_thread+0x4d/0x3e0 kthread+0x105/0x140 ? process_one_work+0x5f0/0x5f0 ? kthread_park+0x90/0x90 ret_from_fork+0x3a/0x50 Signed-off-by: Luis Henriques <lhenriques@suse.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit fe163e5 ] syzbot reported: BUG: KMSAN: uninit-value in capi_write+0x791/0xa90 drivers/isdn/capi/capi.c:700 CPU: 0 PID: 10025 Comm: syz-executor379 Not tainted 4.20.0-rc7+ #2 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x173/0x1d0 lib/dump_stack.c:113 kmsan_report+0x12e/0x2a0 mm/kmsan/kmsan.c:613 __msan_warning+0x82/0xf0 mm/kmsan/kmsan_instr.c:313 capi_write+0x791/0xa90 drivers/isdn/capi/capi.c:700 do_loop_readv_writev fs/read_write.c:703 [inline] do_iter_write+0x83e/0xd80 fs/read_write.c:961 vfs_writev fs/read_write.c:1004 [inline] do_writev+0x397/0x840 fs/read_write.c:1039 __do_sys_writev fs/read_write.c:1112 [inline] __se_sys_writev+0x9b/0xb0 fs/read_write.c:1109 __x64_sys_writev+0x4a/0x70 fs/read_write.c:1109 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x63/0xe7 [...] The problem is that capi_write() is reading past the end of the message. Fix it by checking the message's length in the needed places. Reported-and-tested-by: syzbot+0849c524d9c634f5ae66@syzkaller.appspotmail.com Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 79c92ca ] When receiving a deauthentication/disassociation frame from a TDLS peer, a station should not disconnect the current AP, but only disable the current TDLS link if it's enabled. Without this change, a TDLS issue can be reproduced by following the steps as below: 1. STA-1 and STA-2 are connected to AP, bidirection traffic is running between STA-1 and STA-2. 2. Set up TDLS link between STA-1 and STA-2, stay for a while, then teardown TDLS link. 3. Repeat step #2 and monitor the connection between STA and AP. During the test, one STA may send a deauthentication/disassociation frame to another, after TDLS teardown, with reason code 6/7, which means: Class 2/3 frame received from nonassociated STA. On receive this frame, the receiver STA will disconnect the current AP and then reconnect. It's not a expected behavior, purpose of this frame should be disabling the TDLS link, not the link with AP. Cc: stable@vger.kernel.org Signed-off-by: Yu Wang <yyuwang@codeaurora.org> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit f8659d6 upstream. Define the working variables to be unsigned long to be compatible with for_each_set_bit and change types as needed. While we are at it remove unused variables from a couple of functions. This was found because of the following KASAN warning: ================================================================== BUG: KASAN: stack-out-of-bounds in find_first_bit+0x19/0x70 Read of size 8 at addr ffff888362d778d0 by task kworker/u308:2/1889 CPU: 21 PID: 1889 Comm: kworker/u308:2 Tainted: G W 5.3.0-rc2-mm1+ #2 Hardware name: Intel Corporation W2600CR/W2600CR, BIOS SE5C600.86B.02.04.0003.102320141138 10/23/2014 Workqueue: ib-comp-unb-wq ib_cq_poll_work [ib_core] Call Trace: dump_stack+0x9a/0xf0 ? find_first_bit+0x19/0x70 print_address_description+0x6c/0x332 ? find_first_bit+0x19/0x70 ? find_first_bit+0x19/0x70 __kasan_report.cold.6+0x1a/0x3b ? find_first_bit+0x19/0x70 kasan_report+0xe/0x12 find_first_bit+0x19/0x70 pma_get_opa_portstatus+0x5cc/0xa80 [hfi1] ? ret_from_fork+0x3a/0x50 ? pma_get_opa_port_ectrs+0x200/0x200 [hfi1] ? stack_trace_consume_entry+0x80/0x80 hfi1_process_mad+0x39b/0x26c0 [hfi1] ? __lock_acquire+0x65e/0x21b0 ? clear_linkup_counters+0xb0/0xb0 [hfi1] ? check_chain_key+0x1d7/0x2e0 ? lock_downgrade+0x3a0/0x3a0 ? match_held_lock+0x2e/0x250 ib_mad_recv_done+0x698/0x15e0 [ib_core] ? clear_linkup_counters+0xb0/0xb0 [hfi1] ? ib_mad_send_done+0xc80/0xc80 [ib_core] ? mark_held_locks+0x79/0xa0 ? _raw_spin_unlock_irqrestore+0x44/0x60 ? rvt_poll_cq+0x1e1/0x340 [rdmavt] __ib_process_cq+0x97/0x100 [ib_core] ib_cq_poll_work+0x31/0xb0 [ib_core] process_one_work+0x4ee/0xa00 ? pwq_dec_nr_in_flight+0x110/0x110 ? do_raw_spin_lock+0x113/0x1d0 worker_thread+0x57/0x5a0 ? process_one_work+0xa00/0xa00 kthread+0x1bb/0x1e0 ? kthread_create_on_node+0xc0/0xc0 ret_from_fork+0x3a/0x50 The buggy address belongs to the page: page:ffffea000d8b5dc0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0x17ffffc0000000() raw: 0017ffffc0000000 0000000000000000 ffffea000d8b5dc8 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected addr ffff888362d778d0 is located in stack of task kworker/u308:2/1889 at offset 32 in frame: pma_get_opa_portstatus+0x0/0xa80 [hfi1] this frame has 1 object: [32, 36) 'vl_select_mask' Memory state around the buggy address: ffff888362d77780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888362d77800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888362d77880: 00 00 00 00 00 00 f1 f1 f1 f1 04 f2 f2 f2 00 00 ^ ffff888362d77900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888362d77980: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 04 f2 f2 f2 ================================================================== Cc: <stable@vger.kernel.org> Fixes: 7724105 ("IB/hfi1: add driver files") Link: https://lore.kernel.org/r/20190911113053.126040.47327.stgit@awfm-01.aw.intel.com Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Kaike Wan <kaike.wan@intel.com> Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit ab57588 upstream. ccw console is created early in start_kernel and used before css is initialized or ccw console subchannel is registered. Until then console subchannel does not have a parent. For that reason assume subchannels with no parent are not pseudo subchannels. This fixes the following kasan finding: BUG: KASAN: global-out-of-bounds in sch_is_pseudo_sch+0x8e/0x98 Read of size 8 at addr 00000000000005e8 by task swapper/0/0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.3.0-rc8-07370-g6ac43dd12538 #2 Hardware name: IBM 2964 NC9 702 (z/VM 6.4.0) Call Trace: ([<000000000012cd76>] show_stack+0x14e/0x1e0) [<0000000001f7fb44>] dump_stack+0x1a4/0x1f8 [<00000000007d7afc>] print_address_description+0x64/0x3c8 [<00000000007d75f6>] __kasan_report+0x14e/0x180 [<00000000018a2986>] sch_is_pseudo_sch+0x8e/0x98 [<000000000189b950>] cio_enable_subchannel+0x1d0/0x510 [<00000000018cac7c>] ccw_device_recognition+0x12c/0x188 [<0000000002ceb1a8>] ccw_device_enable_console+0x138/0x340 [<0000000002cf1cbe>] con3215_init+0x25e/0x300 [<0000000002c8770a>] console_init+0x68a/0x9b8 [<0000000002c6a3d6>] start_kernel+0x4fe/0x728 [<0000000000100070>] startup_continue+0x70/0xd0 Cc: stable@vger.kernel.org Reviewed-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 0216234 ] We release wrong pointer on error path in cpu_cache_level__read function, leading to segfault: (gdb) r record ls Starting program: /root/perf/tools/perf/perf record ls ... [ perf record: Woken up 1 times to write data ] double free or corruption (out) Thread 1 "perf" received signal SIGABRT, Aborted. 0x00007ffff7463798 in raise () from /lib64/power9/libc.so.6 (gdb) bt #0 0x00007ffff7463798 in raise () from /lib64/power9/libc.so.6 #1 0x00007ffff7443bac in abort () from /lib64/power9/libc.so.6 #2 0x00007ffff74af8bc in __libc_message () from /lib64/power9/libc.so.6 #3 0x00007ffff74b92b8 in malloc_printerr () from /lib64/power9/libc.so.6 #4 0x00007ffff74bb874 in _int_free () from /lib64/power9/libc.so.6 khadas#5 0x0000000010271260 in __zfree (ptr=0x7fffffffa0b0) at ../../lib/zalloc.. khadas#6 0x0000000010139340 in cpu_cache_level__read (cache=0x7fffffffa090, cac.. khadas#7 0x0000000010143c90 in build_caches (cntp=0x7fffffffa118, size=<optimiz.. ... Releasing the proper pointer. Fixes: 720e98b ("perf tools: Add perf data cache feature") Signed-off-by: Jiri Olsa <jolsa@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Michael Petlan <mpetlan@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: stable@vger.kernel.org: # v4.6+ Link: http://lore.kernel.org/lkml/20190912105235.10689-1-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 443f2d5 ] Observe a segmentation fault when 'perf stat' is asked to repeat forever with the interval option. Without fix: # perf stat -r 0 -I 5000 -e cycles -a sleep 10 # time counts unit events 5.000211692 3,13,89,82,34,157 cycles 10.000380119 1,53,98,52,22,294 cycles 10.040467280 17,16,79,265 cycles Segmentation fault This problem was only observed when we use forever option aka -r 0 and works with limited repeats. Calling print_counter with ts being set to NULL, is not a correct option when interval is set. Hence avoid print_counter(NULL,..) if interval is set. With fix: # perf stat -r 0 -I 5000 -e cycles -a sleep 10 # time counts unit events 5.019866622 3,15,14,43,08,697 cycles 10.039865756 3,15,16,31,95,261 cycles 10.059950628 1,26,05,47,158 cycles 5.009902655 3,14,52,62,33,932 cycles 10.019880228 3,14,52,22,89,154 cycles 10.030543876 66,90,18,333 cycles 5.009848281 3,14,51,98,25,437 cycles 10.029854402 3,15,14,93,04,918 cycles 5.009834177 3,14,51,95,92,316 cycles Committer notes: Did the 'git bisect' to find the cset introducing the problem to add the Fixes tag below, and at that time the problem reproduced as: (gdb) run stat -r0 -I500 sleep 1 <SNIP> Program received signal SIGSEGV, Segmentation fault. print_interval (prefix=prefix@entry=0x7fffffffc8d0 "", ts=ts@entry=0x0) at builtin-stat.c:866 866 sprintf(prefix, "%6lu.%09lu%s", ts->tv_sec, ts->tv_nsec, csv_sep); (gdb) bt #0 print_interval (prefix=prefix@entry=0x7fffffffc8d0 "", ts=ts@entry=0x0) at builtin-stat.c:866 #1 0x000000000041860a in print_counters (ts=ts@entry=0x0, argc=argc@entry=2, argv=argv@entry=0x7fffffffd640) at builtin-stat.c:938 #2 0x0000000000419a7f in cmd_stat (argc=2, argv=0x7fffffffd640, prefix=<optimized out>) at builtin-stat.c:1411 #3 0x000000000045c65a in run_builtin (p=p@entry=0x6291b8 <commands+216>, argc=argc@entry=5, argv=argv@entry=0x7fffffffd640) at perf.c:370 #4 0x000000000045c893 in handle_internal_command (argc=5, argv=0x7fffffffd640) at perf.c:429 khadas#5 0x000000000045c8f1 in run_argv (argcp=argcp@entry=0x7fffffffd4ac, argv=argv@entry=0x7fffffffd4a0) at perf.c:473 khadas#6 0x000000000045cac9 in main (argc=<optimized out>, argv=<optimized out>) at perf.c:588 (gdb) Mostly the same as just before this patch: Program received signal SIGSEGV, Segmentation fault. 0x00000000005874a7 in print_interval (config=0xa1f2a0 <stat_config>, evlist=0xbc9b90, prefix=0x7fffffffd1c0 "`", ts=0x0) at util/stat-display.c:964 964 sprintf(prefix, "%6lu.%09lu%s", ts->tv_sec, ts->tv_nsec, config->csv_sep); (gdb) bt #0 0x00000000005874a7 in print_interval (config=0xa1f2a0 <stat_config>, evlist=0xbc9b90, prefix=0x7fffffffd1c0 "`", ts=0x0) at util/stat-display.c:964 #1 0x0000000000588047 in perf_evlist__print_counters (evlist=0xbc9b90, config=0xa1f2a0 <stat_config>, _target=0xa1f0c0 <target>, ts=0x0, argc=2, argv=0x7fffffffd670) at util/stat-display.c:1172 #2 0x000000000045390f in print_counters (ts=0x0, argc=2, argv=0x7fffffffd670) at builtin-stat.c:656 #3 0x0000000000456bb5 in cmd_stat (argc=2, argv=0x7fffffffd670) at builtin-stat.c:1960 #4 0x00000000004dd2e0 in run_builtin (p=0xa30e00 <commands+288>, argc=5, argv=0x7fffffffd670) at perf.c:310 khadas#5 0x00000000004dd54d in handle_internal_command (argc=5, argv=0x7fffffffd670) at perf.c:362 khadas#6 0x00000000004dd694 in run_argv (argcp=0x7fffffffd4cc, argv=0x7fffffffd4c0) at perf.c:406 khadas#7 0x00000000004dda11 in main (argc=5, argv=0x7fffffffd670) at perf.c:531 (gdb) Fixes: d4f63a4 ("perf stat: Introduce print_counters function") Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Tested-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: stable@vger.kernel.org # v4.2+ Link: http://lore.kernel.org/lkml/20190904094738.9558-3-srikar@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 2190168 ] On excessive bit errors for the FCP channel ingress fibre path, the channel notifies us. Previously, we only emitted a kernel message and a trace record. Since performance can become suboptimal with I/O timeouts due to bit errors, we now stop using an FCP device by default on channel notification so multipath on top can timely failover to other paths. A new module parameter zfcp.ber_stop can be used to get zfcp old behavior. User explanation of new kernel message: * Description: * The FCP channel reported that its bit error threshold has been exceeded. * These errors might result from a problem with the physical components * of the local fibre link into the FCP channel. * The problem might be damage or malfunction of the cable or * cable connection between the FCP channel and * the adjacent fabric switch port or the point-to-point peer. * Find details about the errors in the HBA trace for the FCP device. * The zfcp device driver closed down the FCP device * to limit the performance impact from possible I/O command timeouts. * User action: * Check for problems on the local fibre link, ensure that fibre optics are * clean and functional, and all cables are properly plugged. * After the repair action, you can manually recover the FCP device by * writing "0" into its "failed" sysfs attribute. * If recovery through sysfs is not possible, set the CHPID of the device * offline and back online on the service element. Fixes: 1da177e ("Linux-2.6.12-rc2") Cc: <stable@vger.kernel.org> #2.6.30+ Link: https://lore.kernel.org/r/20191001104949.42810-1-maier@linux.ibm.com Reviewed-by: Jens Remus <jremus@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Steffen Maier <maier@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit e4f8e51 upstream. A long time ago we fixed a similar deadlock in show_slab_objects() [1]. However, it is apparently due to the commits like 01fb58b ("slab: remove synchronous synchronize_sched() from memcg cache deactivation path") and 03afc0e ("slab: get_online_mems for kmem_cache_{create,destroy,shrink}"), this kind of deadlock is back by just reading files in /sys/kernel/slab which will generate a lockdep splat below. Since the "mem_hotplug_lock" here is only to obtain a stable online node mask while racing with NUMA node hotplug, in the worst case, the results may me miscalculated while doing NUMA node hotplug, but they shall be corrected by later reads of the same files. WARNING: possible circular locking dependency detected ------------------------------------------------------ cat/5224 is trying to acquire lock: ffff900012ac3120 (mem_hotplug_lock.rw_sem){++++}, at: show_slab_objects+0x94/0x3a8 but task is already holding lock: b8ff009693eee398 (kn->count#45){++++}, at: kernfs_seq_start+0x44/0xf0 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (kn->count#45){++++}: lock_acquire+0x31c/0x360 __kernfs_remove+0x290/0x490 kernfs_remove+0x30/0x44 sysfs_remove_dir+0x70/0x88 kobject_del+0x50/0xb0 sysfs_slab_unlink+0x2c/0x38 shutdown_cache+0xa0/0xf0 kmemcg_cache_shutdown_fn+0x1c/0x34 kmemcg_workfn+0x44/0x64 process_one_work+0x4f4/0x950 worker_thread+0x390/0x4bc kthread+0x1cc/0x1e8 ret_from_fork+0x10/0x18 -> #1 (slab_mutex){+.+.}: lock_acquire+0x31c/0x360 __mutex_lock_common+0x16c/0xf78 mutex_lock_nested+0x40/0x50 memcg_create_kmem_cache+0x38/0x16c memcg_kmem_cache_create_func+0x3c/0x70 process_one_work+0x4f4/0x950 worker_thread+0x390/0x4bc kthread+0x1cc/0x1e8 ret_from_fork+0x10/0x18 -> #0 (mem_hotplug_lock.rw_sem){++++}: validate_chain+0xd10/0x2bcc __lock_acquire+0x7f4/0xb8c lock_acquire+0x31c/0x360 get_online_mems+0x54/0x150 show_slab_objects+0x94/0x3a8 total_objects_show+0x28/0x34 slab_attr_show+0x38/0x54 sysfs_kf_seq_show+0x198/0x2d4 kernfs_seq_show+0xa4/0xcc seq_read+0x30c/0x8a8 kernfs_fop_read+0xa8/0x314 __vfs_read+0x88/0x20c vfs_read+0xd8/0x10c ksys_read+0xb0/0x120 __arm64_sys_read+0x54/0x88 el0_svc_handler+0x170/0x240 el0_svc+0x8/0xc other info that might help us debug this: Chain exists of: mem_hotplug_lock.rw_sem --> slab_mutex --> kn->count#45 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(kn->count#45); lock(slab_mutex); lock(kn->count#45); lock(mem_hotplug_lock.rw_sem); *** DEADLOCK *** 3 locks held by cat/5224: #0: 9eff00095b14b2a0 (&p->lock){+.+.}, at: seq_read+0x4c/0x8a8 #1: 0eff008997041480 (&of->mutex){+.+.}, at: kernfs_seq_start+0x34/0xf0 #2: b8ff009693eee398 (kn->count#45){++++}, at: kernfs_seq_start+0x44/0xf0 stack backtrace: Call trace: dump_backtrace+0x0/0x248 show_stack+0x20/0x2c dump_stack+0xd0/0x140 print_circular_bug+0x368/0x380 check_noncircular+0x248/0x250 validate_chain+0xd10/0x2bcc __lock_acquire+0x7f4/0xb8c lock_acquire+0x31c/0x360 get_online_mems+0x54/0x150 show_slab_objects+0x94/0x3a8 total_objects_show+0x28/0x34 slab_attr_show+0x38/0x54 sysfs_kf_seq_show+0x198/0x2d4 kernfs_seq_show+0xa4/0xcc seq_read+0x30c/0x8a8 kernfs_fop_read+0xa8/0x314 __vfs_read+0x88/0x20c vfs_read+0xd8/0x10c ksys_read+0xb0/0x120 __arm64_sys_read+0x54/0x88 el0_svc_handler+0x170/0x240 el0_svc+0x8/0xc I think it is important to mention that this doesn't expose the show_slab_objects to use-after-free. There is only a single path that might really race here and that is the slab hotplug notifier callback __kmem_cache_shrink (via slab_mem_going_offline_callback) but that path doesn't really destroy kmem_cache_node data structures. [1] http://lkml.iu.edu/hypermail/linux/kernel/1101.0/02850.html [akpm@linux-foundation.org: add comment explaining why we don't need mem_hotplug_lock] Link: http://lkml.kernel.org/r/1570192309-10132-1-git-send-email-cai@lca.pw Fixes: 01fb58b ("slab: remove synchronous synchronize_sched() from memcg cache deactivation path") Fixes: 03afc0e ("slab: get_online_mems for kmem_cache_{create,destroy,shrink}") Signed-off-by: Qian Cai <cai@lca.pw> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Roman Gushchin <guro@fb.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit b66f31e ] This patch fixes the lock inversion complaint: ============================================ WARNING: possible recursive locking detected 5.3.0-rc7-dbg+ #1 Not tainted -------------------------------------------- kworker/u16:6/171 is trying to acquire lock: 00000000035c6e6c (&id_priv->handler_mutex){+.+.}, at: rdma_destroy_id+0x78/0x4a0 [rdma_cm] but task is already holding lock: 00000000bc7c307d (&id_priv->handler_mutex){+.+.}, at: iw_conn_req_handler+0x151/0x680 [rdma_cm] other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&id_priv->handler_mutex); lock(&id_priv->handler_mutex); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by kworker/u16:6/171: #0: 00000000e2eaa773 ((wq_completion)iw_cm_wq){+.+.}, at: process_one_work+0x472/0xac0 #1: 000000001efd357b ((work_completion)(&work->work)#3){+.+.}, at: process_one_work+0x476/0xac0 #2: 00000000bc7c307d (&id_priv->handler_mutex){+.+.}, at: iw_conn_req_handler+0x151/0x680 [rdma_cm] stack backtrace: CPU: 3 PID: 171 Comm: kworker/u16:6 Not tainted 5.3.0-rc7-dbg+ #1 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 Workqueue: iw_cm_wq cm_work_handler [iw_cm] Call Trace: dump_stack+0x8a/0xd6 __lock_acquire.cold+0xe1/0x24d lock_acquire+0x106/0x240 __mutex_lock+0x12e/0xcb0 mutex_lock_nested+0x1f/0x30 rdma_destroy_id+0x78/0x4a0 [rdma_cm] iw_conn_req_handler+0x5c9/0x680 [rdma_cm] cm_work_handler+0xe62/0x1100 [iw_cm] process_one_work+0x56d/0xac0 worker_thread+0x7a/0x5d0 kthread+0x1bc/0x210 ret_from_fork+0x24/0x30 This is not a bug as there are actually two lock classes here. Link: https://lore.kernel.org/r/20190930231707.48259-3-bvanassche@acm.org Fixes: de910bd ("RDMA/cma: Simplify locking needed for serialization of callbacks") Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 159d2c7 upstream. qdisc_root() use from netem_enqueue() triggers a lockdep warning. __dev_queue_xmit() uses rcu_read_lock_bh() which is not equivalent to rcu_read_lock() + local_bh_disable_bh as far as lockdep is concerned. WARNING: suspicious RCU usage 5.3.0-rc7+ #0 Not tainted ----------------------------- include/net/sch_generic.h:492 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 3 locks held by syz-executor427/8855: #0: 00000000b5525c01 (rcu_read_lock_bh){....}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:92 [inline] #0: 00000000b5525c01 (rcu_read_lock_bh){....}, at: ip_finish_output2+0x2dc/0x2570 net/ipv4/ip_output.c:214 #1: 00000000b5525c01 (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x20a/0x3650 net/core/dev.c:3804 #2: 00000000364bae92 (&(&sch->q.lock)->rlock){+.-.}, at: spin_lock include/linux/spinlock.h:338 [inline] #2: 00000000364bae92 (&(&sch->q.lock)->rlock){+.-.}, at: __dev_xmit_skb net/core/dev.c:3502 [inline] #2: 00000000364bae92 (&(&sch->q.lock)->rlock){+.-.}, at: __dev_queue_xmit+0x14b8/0x3650 net/core/dev.c:3838 stack backtrace: CPU: 0 PID: 8855 Comm: syz-executor427 Not tainted 5.3.0-rc7+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 lockdep_rcu_suspicious+0x153/0x15d kernel/locking/lockdep.c:5357 qdisc_root include/net/sch_generic.h:492 [inline] netem_enqueue+0x1cfb/0x2d80 net/sched/sch_netem.c:479 __dev_xmit_skb net/core/dev.c:3527 [inline] __dev_queue_xmit+0x15d2/0x3650 net/core/dev.c:3838 dev_queue_xmit+0x18/0x20 net/core/dev.c:3902 neigh_hh_output include/net/neighbour.h:500 [inline] neigh_output include/net/neighbour.h:509 [inline] ip_finish_output2+0x1726/0x2570 net/ipv4/ip_output.c:228 __ip_finish_output net/ipv4/ip_output.c:308 [inline] __ip_finish_output+0x5fc/0xb90 net/ipv4/ip_output.c:290 ip_finish_output+0x38/0x1f0 net/ipv4/ip_output.c:318 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip_mc_output+0x292/0xf40 net/ipv4/ip_output.c:417 dst_output include/net/dst.h:436 [inline] ip_local_out+0xbb/0x190 net/ipv4/ip_output.c:125 ip_send_skb+0x42/0xf0 net/ipv4/ip_output.c:1555 udp_send_skb.isra.0+0x6b2/0x1160 net/ipv4/udp.c:887 udp_sendmsg+0x1e96/0x2820 net/ipv4/udp.c:1174 inet_sendmsg+0x9e/0xe0 net/ipv4/af_inet.c:807 sock_sendmsg_nosec net/socket.c:637 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:657 ___sys_sendmsg+0x3e2/0x920 net/socket.c:2311 __sys_sendmmsg+0x1bf/0x4d0 net/socket.c:2413 __do_sys_sendmmsg net/socket.c:2442 [inline] __se_sys_sendmmsg net/socket.c:2439 [inline] __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2439 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 6408136 ] We've recently seen a workload on XFS filesystems with a repeatable deadlock between background writeback and a multi-process application doing concurrent writes and fsyncs to a small range of a file. range_cyclic writeback Process 1 Process 2 xfs_vm_writepages write_cache_pages writeback_index = 2 cycled = 0 .... find page 2 dirty lock Page 2 ->writepage page 2 writeback page 2 clean page 2 added to bio no more pages write() locks page 1 dirties page 1 locks page 2 dirties page 1 fsync() .... xfs_vm_writepages write_cache_pages start index 0 find page 1 towrite lock Page 1 ->writepage page 1 writeback page 1 clean page 1 added to bio find page 2 towrite lock Page 2 page 2 is writeback <blocks> write() locks page 1 dirties page 1 fsync() .... xfs_vm_writepages write_cache_pages start index 0 !done && !cycled sets index to 0, restarts lookup find page 1 dirty find page 1 towrite lock Page 1 page 1 is writeback <blocks> lock Page 1 <blocks> DEADLOCK because: - process 1 needs page 2 writeback to complete to make enough progress to issue IO pending for page 1 - writeback needs page 1 writeback to complete so process 2 can progress and unlock the page it is blocked on, then it can issue the IO pending for page 2 - process 2 can't make progress until process 1 issues IO for page 1 The underlying cause of the problem here is that range_cyclic writeback is processing pages in descending index order as we hold higher index pages in a structure controlled from above write_cache_pages(). The write_cache_pages() caller needs to be able to submit these pages for IO before write_cache_pages restarts writeback at mapping index 0 to avoid wcp inverting the page lock/writeback wait order. generic_writepages() is not susceptible to this bug as it has no private context held across write_cache_pages() - filesystems using this infrastructure always submit pages in ->writepage immediately and so there is no problem with range_cyclic going back to mapping index 0. However: mpage_writepages() has a private bio context, exofs_writepages() has page_collect fuse_writepages() has fuse_fill_wb_data nfs_writepages() has nfs_pageio_descriptor xfs_vm_writepages() has xfs_writepage_ctx All of these ->writepages implementations can hold pages under writeback in their private structures until write_cache_pages() returns, and hence they are all susceptible to this deadlock. Also worth noting is that ext4 has it's own bastardised version of write_cache_pages() and so it /may/ have an equivalent deadlock. I looked at the code long enough to understand that it has a similar retry loop for range_cyclic writeback reaching the end of the file and then promptly ran away before my eyes bled too much. I'll leave it for the ext4 developers to determine if their code is actually has this deadlock and how to fix it if it has. There's a few ways I can see avoid this deadlock. There's probably more, but these are the first I've though of: 1. get rid of range_cyclic altogether 2. range_cyclic always stops at EOF, and we start again from writeback index 0 on the next call into write_cache_pages() 2a. wcp also returns EAGAIN to ->writepages implementations to indicate range cyclic has hit EOF. writepages implementations can then flush the current context and call wpc again to continue. i.e. lift the retry into the ->writepages implementation 3. range_cyclic uses trylock_page() rather than lock_page(), and it skips pages it can't lock without blocking. It will already do this for pages under writeback, so this seems like a no-brainer 3a. all non-WB_SYNC_ALL writeback uses trylock_page() to avoid blocking as per pages under writeback. I don't think #1 is an option - range_cyclic prevents frequently dirtied lower file offset from starving background writeback of rarely touched higher file offsets. #2 is simple, and I don't think it will have any impact on performance as going back to the start of the file implies an immediate seek. We'll have exactly the same number of seeks if we switch writeback to another inode, and then come back to this one later and restart from index 0. #2a is pretty much "status quo without the deadlock". Moving the retry loop up into the wcp caller means we can issue IO on the pending pages before calling wcp again, and so avoid locking or waiting on pages in the wrong order. I'm not convinced we need to do this given that we get the same thing from #2 on the next writeback call from the writeback infrastructure. #3 is really just a band-aid - it doesn't fix the access/wait inversion problem, just prevents it from becoming a deadlock situation. I'd prefer we fix the inversion, not sweep it under the carpet like this. #3a is really an optimisation that just so happens to include the band-aid fix of #3. So it seems that the simplest way to fix this issue is to implement solution #2 Link: http://lkml.kernel.org/r/20181005054526.21507-1-david@fromorbit.com Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Jan Kara <jack@suse.de> Cc: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 42ffb0b] There exists a deadlock with range_cyclic that has existed forever. If we loop around with a bio already built we could deadlock with a writer who has the page locked that we're attempting to write but is waiting on a page in our bio to be written out. The task traces are as follows PID: 1329874 TASK: ffff889ebcdf3800 CPU: 33 COMMAND: "kworker/u113:5" #0 [ffffc900297bb658] __schedule at ffffffff81a4c33f #1 [ffffc900297bb6e0] schedule at ffffffff81a4c6e3 #2 [ffffc900297bb6f8] io_schedule at ffffffff81a4ca42 #3 [ffffc900297bb708] __lock_page at ffffffff811f145b #4 [ffffc900297bb798] __process_pages_contig at ffffffff814bc502 khadas#5 [ffffc900297bb8c8] lock_delalloc_pages at ffffffff814bc684 khadas#6 [ffffc900297bb900] find_lock_delalloc_range at ffffffff814be9ff khadas#7 [ffffc900297bb9a0] writepage_delalloc at ffffffff814bebd0 khadas#8 [ffffc900297bba18] __extent_writepage at ffffffff814bfbf2 khadas#9 [ffffc900297bba98] extent_write_cache_pages at ffffffff814bffbd PID: 2167901 TASK: ffff889dc6a59c00 CPU: 14 COMMAND: "aio-dio-invalid" #0 [ffffc9003b50bb18] __schedule at ffffffff81a4c33f #1 [ffffc9003b50bba0] schedule at ffffffff81a4c6e3 #2 [ffffc9003b50bbb8] io_schedule at ffffffff81a4ca42 #3 [ffffc9003b50bbc8] wait_on_page_bit at ffffffff811f24d6 #4 [ffffc9003b50bc60] prepare_pages at ffffffff814b05a7 khadas#5 [ffffc9003b50bcd8] btrfs_buffered_write at ffffffff814b1359 khadas#6 [ffffc9003b50bdb0] btrfs_file_write_iter at ffffffff814b5933 khadas#7 [ffffc9003b50be38] new_sync_write at ffffffff8128f6a8 khadas#8 [ffffc9003b50bec8] vfs_write at ffffffff81292b9d khadas#9 [ffffc9003b50bf00] ksys_pwrite64 at ffffffff81293032 I used drgn to find the respective pages we were stuck on page_entry.page 0xffffea00fbfc7500 index 8148 bit 15 pid 2167901 page_entry.page 0xffffea00f9bb7400 index 7680 bit 0 pid 1329874 As you can see the kworker is waiting for bit 0 (PG_locked) on index 7680, and aio-dio-invalid is waiting for bit 15 (PG_writeback) on index 8148. aio-dio-invalid has 7680, and the kworker epd looks like the following crash> struct extent_page_data ffffc900297bbbb0 struct extent_page_data { bio = 0xffff889f747ed830, tree = 0xffff889eed6ba448, extent_locked = 0, sync_io = 0 } Probably worth mentioning as well that it waits for writeback of the page to complete while holding a lock on it (at prepare_pages()). Using drgn I walked the bio pages looking for page 0xffffea00fbfc7500 which is the one we're waiting for writeback on bio = Object(prog, 'struct bio', address=0xffff889f747ed830) for i in range(0, bio.bi_vcnt.value_()): bv = bio.bi_io_vec[i] if bv.bv_page.value_() == 0xffffea00fbfc7500: print("FOUND IT") which validated what I suspected. The fix for this is simple, flush the epd before we loop back around to the beginning of the file during writeout. Fixes: b293f02 ("Btrfs: Add writepages support") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit db735fc ] Turning on CONFIG_DMA_API_DEBUG_SG results in the following error: [ 12.078665] msm ae00000.mdss: DMA-API: mapping sg segment longer than device claims to support [len=3526656] [max=65536] [ 12.089870] WARNING: CPU: 6 PID: 334 at /mnt/host/source/src/third_party/kernel/v4.19/kernel/dma/debug.c:1301 debug_dma_map_sg+0x1dc/0x318 [ 12.102655] Modules linked in: joydev [ 12.106442] CPU: 6 PID: 334 Comm: frecon Not tainted 4.19.0 #2 [ 12.112450] Hardware name: Google Cheza (rev3+) (DT) [ 12.117566] pstate: 60400009 (nZCv daif +PAN -UAO) [ 12.122506] pc : debug_dma_map_sg+0x1dc/0x318 [ 12.126995] lr : debug_dma_map_sg+0x1dc/0x318 [ 12.131487] sp : ffffff800cc3ba80 [ 12.134913] x29: ffffff800cc3ba80 x28: 0000000000000000 [ 12.140395] x27: 0000000000000004 x26: 0000000000000004 [ 12.145868] x25: ffffff8008e55b18 x24: 0000000000000000 [ 12.151337] x23: 00000000ffffffff x22: ffffff800921c000 [ 12.156809] x21: ffffffc0fa75b080 x20: ffffffc0f7195090 [ 12.162280] x19: ffffffc0f1c53280 x18: 0000000000000000 [ 12.167749] x17: 0000000000000000 x16: 0000000000000000 [ 12.173218] x15: 0000000000000000 x14: 0720072007200720 [ 12.178689] x13: 0720072007200720 x12: 0720072007200720 [ 12.184161] x11: 0720072007200720 x10: 0720072007200720 [ 12.189641] x9 : ffffffc0f1fc6b60 x8 : 0000000000000000 [ 12.195110] x7 : ffffff8008132ce0 x6 : 0000000000000000 [ 12.200585] x5 : 0000000000000000 x4 : ffffff8008134734 [ 12.206058] x3 : ffffff800cc3b830 x2 : ffffffc0f1fc6240 [ 12.211532] x1 : 25045a74f48a7400 x0 : 25045a74f48a7400 [ 12.217006] Call trace: [ 12.219535] debug_dma_map_sg+0x1dc/0x318 [ 12.223671] get_pages+0x19c/0x20c [ 12.227177] msm_gem_fault+0x64/0xfc [ 12.230874] __do_fault+0x3c/0x140 [ 12.234383] __handle_mm_fault+0x70c/0xdb8 [ 12.238603] handle_mm_fault+0xac/0xc4 [ 12.242473] do_page_fault+0x1bc/0x3d4 [ 12.246342] do_translation_fault+0x54/0x88 [ 12.250652] do_mem_abort+0x60/0xf0 [ 12.254250] el0_da+0x20/0x24 [ 12.257317] irq event stamp: 67260 [ 12.260828] hardirqs last enabled at (67259): [<ffffff8008132d0c>] console_unlock+0x214/0x608 [ 12.269693] hardirqs last disabled at (67260): [<ffffff8008080e0c>] do_debug_exception+0x5c/0x178 [ 12.278820] softirqs last enabled at (67256): [<ffffff8008081664>] __do_softirq+0x4d4/0x520 [ 12.287510] softirqs last disabled at (67249): [<ffffff80080be574>] irq_exit+0xa8/0x100 [ 12.295742] ---[ end trace e63cfc40c313ffab ]--- The root of the problem is that the default segment size for sgt is (UINT_MAX & PAGE_MASK), and the default segment size for device dma is 64K. As such, if you compare the 2, you would deduce that the sg segment will overflow the device's capacity. In reality, the hardware can accommodate the larger sg segments, it's just not initializing its max segment properly. This patch initializes the max segment size for the mdss device, which gets rid of that pesky warning. Reported-by: Stephen Boyd <swboyd@chromium.org> Tested-by: Stephen Boyd <swboyd@chromium.org> Tested-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> Reviewed-by: Rob Clark <robdclark@gmail.com> Signed-off-by: Sean Paul <seanpaul@chromium.org> Signed-off-by: Douglas Anderson <dianders@chromium.org> Link: https://patchwork.freedesktop.org/patch/msgid/20200121111813.REPOST.1.I92c66a35fb13f368095b05287bdabdbe88ca6922@changeid Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit e8c75a3 upstream. sel_lock cannot nest in the console lock. Thanks to syzkaller, the kernel states firmly: > WARNING: possible circular locking dependency detected > 5.6.0-rc3-syzkaller #0 Not tainted > ------------------------------------------------------ > syz-executor.4/20336 is trying to acquire lock: > ffff8880a2e952a0 (&tty->termios_rwsem){++++}, at: tty_unthrottle+0x22/0x100 drivers/tty/tty_ioctl.c:136 > > but task is already holding lock: > ffffffff89462e70 (sel_lock){+.+.}, at: paste_selection+0x118/0x470 drivers/tty/vt/selection.c:374 > > which lock already depends on the new lock. > > the existing dependency chain (in reverse order) is: > > -> #2 (sel_lock){+.+.}: > mutex_lock_nested+0x1b/0x30 kernel/locking/mutex.c:1118 > set_selection_kernel+0x3b8/0x18a0 drivers/tty/vt/selection.c:217 > set_selection_user+0x63/0x80 drivers/tty/vt/selection.c:181 > tioclinux+0x103/0x530 drivers/tty/vt/vt.c:3050 > vt_ioctl+0x3f1/0x3a30 drivers/tty/vt/vt_ioctl.c:364 This is ioctl(TIOCL_SETSEL). Locks held on the path: console_lock -> sel_lock > -> #1 (console_lock){+.+.}: > console_lock+0x46/0x70 kernel/printk/printk.c:2289 > con_flush_chars+0x50/0x650 drivers/tty/vt/vt.c:3223 > n_tty_write+0xeae/0x1200 drivers/tty/n_tty.c:2350 > do_tty_write drivers/tty/tty_io.c:962 [inline] > tty_write+0x5a1/0x950 drivers/tty/tty_io.c:1046 This is write(). Locks held on the path: termios_rwsem -> console_lock > -> #0 (&tty->termios_rwsem){++++}: > down_write+0x57/0x140 kernel/locking/rwsem.c:1534 > tty_unthrottle+0x22/0x100 drivers/tty/tty_ioctl.c:136 > mkiss_receive_buf+0x12aa/0x1340 drivers/net/hamradio/mkiss.c:902 > tty_ldisc_receive_buf+0x12f/0x170 drivers/tty/tty_buffer.c:465 > paste_selection+0x346/0x470 drivers/tty/vt/selection.c:389 > tioclinux+0x121/0x530 drivers/tty/vt/vt.c:3055 > vt_ioctl+0x3f1/0x3a30 drivers/tty/vt/vt_ioctl.c:364 This is ioctl(TIOCL_PASTESEL). Locks held on the path: sel_lock -> termios_rwsem > other info that might help us debug this: > > Chain exists of: > &tty->termios_rwsem --> console_lock --> sel_lock Clearly. From the above, we have: console_lock -> sel_lock sel_lock -> termios_rwsem termios_rwsem -> console_lock Fix this by reversing the console_lock -> sel_lock dependency in ioctl(TIOCL_SETSEL). First, lock sel_lock, then console_lock. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Reported-by: syzbot+26183d9746e62da329b8@syzkaller.appspotmail.com Fixes: 07e6124 ("vt: selection, close sel_buffer race") Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200228115406.5735-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 6c5d911 ] journal_head::b_transaction and journal_head::b_next_transaction could be accessed concurrently as noticed by KCSAN, LTP: starting fsync04 /dev/zero: Can't open blockdev EXT4-fs (loop0): mounting ext3 file system using the ext4 subsystem EXT4-fs (loop0): mounted filesystem with ordered data mode. Opts: (null) ================================================================== BUG: KCSAN: data-race in __jbd2_journal_refile_buffer [jbd2] / jbd2_write_access_granted [jbd2] write to 0xffff99f9b1bd0e30 of 8 bytes by task 25721 on cpu 70: __jbd2_journal_refile_buffer+0xdd/0x210 [jbd2] __jbd2_journal_refile_buffer at fs/jbd2/transaction.c:2569 jbd2_journal_commit_transaction+0x2d15/0x3f20 [jbd2] (inlined by) jbd2_journal_commit_transaction at fs/jbd2/commit.c:1034 kjournald2+0x13b/0x450 [jbd2] kthread+0x1cd/0x1f0 ret_from_fork+0x27/0x50 read to 0xffff99f9b1bd0e30 of 8 bytes by task 25724 on cpu 68: jbd2_write_access_granted+0x1b2/0x250 [jbd2] jbd2_write_access_granted at fs/jbd2/transaction.c:1155 jbd2_journal_get_write_access+0x2c/0x60 [jbd2] __ext4_journal_get_write_access+0x50/0x90 [ext4] ext4_mb_mark_diskspace_used+0x158/0x620 [ext4] ext4_mb_new_blocks+0x54f/0xca0 [ext4] ext4_ind_map_blocks+0xc79/0x1b40 [ext4] ext4_map_blocks+0x3b4/0x950 [ext4] _ext4_get_block+0xfc/0x270 [ext4] ext4_get_block+0x3b/0x50 [ext4] __block_write_begin_int+0x22e/0xae0 __block_write_begin+0x39/0x50 ext4_write_begin+0x388/0xb50 [ext4] generic_perform_write+0x15d/0x290 ext4_buffered_write_iter+0x11f/0x210 [ext4] ext4_file_write_iter+0xce/0x9e0 [ext4] new_sync_write+0x29c/0x3b0 __vfs_write+0x92/0xa0 vfs_write+0x103/0x260 ksys_write+0x9d/0x130 __x64_sys_write+0x4c/0x60 do_syscall_64+0x91/0xb05 entry_SYSCALL_64_after_hwframe+0x49/0xbe 5 locks held by fsync04/25724: #0: ffff99f9911093f8 (sb_writers#13){.+.+}, at: vfs_write+0x21c/0x260 #1: ffff99f9db4c0348 (&sb->s_type->i_mutex_key#15){+.+.}, at: ext4_buffered_write_iter+0x65/0x210 [ext4] #2: ffff99f5e7dfcf58 (jbd2_handle){++++}, at: start_this_handle+0x1c1/0x9d0 [jbd2] #3: ffff99f9db4c0168 (&ei->i_data_sem){++++}, at: ext4_map_blocks+0x176/0x950 [ext4] #4: ffffffff99086b40 (rcu_read_lock){....}, at: jbd2_write_access_granted+0x4e/0x250 [jbd2] irq event stamp: 1407125 hardirqs last enabled at (1407125): [<ffffffff980da9b7>] __find_get_block+0x107/0x790 hardirqs last disabled at (1407124): [<ffffffff980da8f9>] __find_get_block+0x49/0x790 softirqs last enabled at (1405528): [<ffffffff98a0034c>] __do_softirq+0x34c/0x57c softirqs last disabled at (1405521): [<ffffffff97cc67a2>] irq_exit+0xa2/0xc0 Reported by Kernel Concurrency Sanitizer on: CPU: 68 PID: 25724 Comm: fsync04 Tainted: G L 5.6.0-rc2-next-20200221+ khadas#7 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019 The plain reads are outside of jh->b_state_lock critical section which result in data races. Fix them by adding pairs of READ|WRITE_ONCE(). Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Qian Cai <cai@lca.pw> Link: https://lore.kernel.org/r/20200222043111.2227-1-cai@lca.pw Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 28936b6 upstream. inode->i_blocks could be accessed concurrently as noticed by KCSAN, BUG: KCSAN: data-race in ext4_do_update_inode [ext4] / inode_add_bytes write to 0xffff9a00d4b982d0 of 8 bytes by task 22100 on cpu 118: inode_add_bytes+0x65/0xf0 __inode_add_bytes at fs/stat.c:689 (inlined by) inode_add_bytes at fs/stat.c:702 ext4_mb_new_blocks+0x418/0xca0 [ext4] ext4_ext_map_blocks+0x1a6b/0x27b0 [ext4] ext4_map_blocks+0x1a9/0x950 [ext4] _ext4_get_block+0xfc/0x270 [ext4] ext4_get_block_unwritten+0x33/0x50 [ext4] __block_write_begin_int+0x22e/0xae0 __block_write_begin+0x39/0x50 ext4_write_begin+0x388/0xb50 [ext4] ext4_da_write_begin+0x35f/0x8f0 [ext4] generic_perform_write+0x15d/0x290 ext4_buffered_write_iter+0x11f/0x210 [ext4] ext4_file_write_iter+0xce/0x9e0 [ext4] new_sync_write+0x29c/0x3b0 __vfs_write+0x92/0xa0 vfs_write+0x103/0x260 ksys_write+0x9d/0x130 __x64_sys_write+0x4c/0x60 do_syscall_64+0x91/0xb05 entry_SYSCALL_64_after_hwframe+0x49/0xbe read to 0xffff9a00d4b982d0 of 8 bytes by task 8 on cpu 65: ext4_do_update_inode+0x4a0/0xf60 [ext4] ext4_inode_blocks_set at fs/ext4/inode.c:4815 ext4_mark_iloc_dirty+0xaf/0x160 [ext4] ext4_mark_inode_dirty+0x129/0x3e0 [ext4] ext4_convert_unwritten_extents+0x253/0x2d0 [ext4] ext4_convert_unwritten_io_end_vec+0xc5/0x150 [ext4] ext4_end_io_rsv_work+0x22c/0x350 [ext4] process_one_work+0x54f/0xb90 worker_thread+0x80/0x5f0 kthread+0x1cd/0x1f0 ret_from_fork+0x27/0x50 4 locks held by kworker/u256:0/8: #0: ffff9a025abc4328 ((wq_completion)ext4-rsv-conversion){+.+.}, at: process_one_work+0x443/0xb90 #1: ffffab5a862dbe20 ((work_completion)(&ei->i_rsv_conversion_work)){+.+.}, at: process_one_work+0x443/0xb90 #2: ffff9a025a9d0f58 (jbd2_handle){++++}, at: start_this_handle+0x1c1/0x9d0 [jbd2] #3: ffff9a00d4b985d8 (&(&ei->i_raw_lock)->rlock){+.+.}, at: ext4_do_update_inode+0xaa/0xf60 [ext4] irq event stamp: 3009267 hardirqs last enabled at (3009267): [<ffffffff980da9b7>] __find_get_block+0x107/0x790 hardirqs last disabled at (3009266): [<ffffffff980da8f9>] __find_get_block+0x49/0x790 softirqs last enabled at (3009230): [<ffffffff98a0034c>] __do_softirq+0x34c/0x57c softirqs last disabled at (3009223): [<ffffffff97cc67a2>] irq_exit+0xa2/0xc0 Reported by Kernel Concurrency Sanitizer on: CPU: 65 PID: 8 Comm: kworker/u256:0 Tainted: G L 5.6.0-rc2-next-20200221+ khadas#7 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019 Workqueue: ext4-rsv-conversion ext4_end_io_rsv_work [ext4] The plain read is outside of inode->i_lock critical section which results in a data race. Fix it by adding READ_ONCE() there. Link: https://lore.kernel.org/r/20200222043258.2279-1-cai@lca.pw Signed-off-by: Qian Cai <cai@lca.pw> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit f0cc2cd ] During unmount we can have a job from the delayed inode items work queue still running, that can lead to at least two bad things: 1) A crash, because the worker can try to create a transaction just after the fs roots were freed; 2) A transaction leak, because the worker can create a transaction before the fs roots are freed and just after we committed the last transaction and after we stopped the transaction kthread. A stack trace example of the crash: [79011.691214] kernel BUG at lib/radix-tree.c:982! [79011.692056] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI [79011.693180] CPU: 3 PID: 1394 Comm: kworker/u8:2 Tainted: G W 5.6.0-rc2-btrfs-next-54 #2 (...) [79011.696789] Workqueue: btrfs-delayed-meta btrfs_work_helper [btrfs] [79011.697904] RIP: 0010:radix_tree_tag_set+0xe7/0x170 (...) [79011.702014] RSP: 0018:ffffb3c84a317ca0 EFLAGS: 00010293 [79011.702949] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [79011.704202] RDX: ffffb3c84a317cb0 RSI: ffffb3c84a317ca8 RDI: ffff8db3931340a0 [79011.705463] RBP: 0000000000000005 R08: 0000000000000005 R09: ffffffff974629d0 [79011.706756] R10: ffffb3c84a317bc0 R11: 0000000000000001 R12: ffff8db393134000 [79011.708010] R13: ffff8db3931340a0 R14: ffff8db393134068 R15: 0000000000000001 [79011.709270] FS: 0000000000000000(0000) GS:ffff8db3b6a00000(0000) knlGS:0000000000000000 [79011.710699] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [79011.711710] CR2: 00007f22c2a0a000 CR3: 0000000232ad4005 CR4: 00000000003606e0 [79011.712958] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [79011.714205] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [79011.715448] Call Trace: [79011.715925] record_root_in_trans+0x72/0xf0 [btrfs] [79011.716819] btrfs_record_root_in_trans+0x4b/0x70 [btrfs] [79011.717925] start_transaction+0xdd/0x5c0 [btrfs] [79011.718829] btrfs_async_run_delayed_root+0x17e/0x2b0 [btrfs] [79011.719915] btrfs_work_helper+0xaa/0x720 [btrfs] [79011.720773] process_one_work+0x26d/0x6a0 [79011.721497] worker_thread+0x4f/0x3e0 [79011.722153] ? process_one_work+0x6a0/0x6a0 [79011.722901] kthread+0x103/0x140 [79011.723481] ? kthread_create_worker_on_cpu+0x70/0x70 [79011.724379] ret_from_fork+0x3a/0x50 (...) The following diagram shows a sequence of steps that lead to the crash during ummount of the filesystem: CPU 1 CPU 2 CPU 3 btrfs_punch_hole() btrfs_btree_balance_dirty() btrfs_balance_delayed_items() --> sees fs_info->delayed_root->items with value 200, which is greater than BTRFS_DELAYED_BACKGROUND (128) and smaller than BTRFS_DELAYED_WRITEBACK (512) btrfs_wq_run_delayed_node() --> queues a job for fs_info->delayed_workers to run btrfs_async_run_delayed_root() btrfs_async_run_delayed_root() --> job queued by CPU 1 --> starts picking and running delayed nodes from the prepare_list list close_ctree() btrfs_delete_unused_bgs() btrfs_commit_super() btrfs_join_transaction() --> gets transaction N btrfs_commit_transaction(N) --> set transaction state to TRANTS_STATE_COMMIT_START btrfs_first_prepared_delayed_node() --> picks delayed node X through the prepared_list list btrfs_run_delayed_items() btrfs_first_delayed_node() --> also picks delayed node X but through the node_list list __btrfs_commit_inode_delayed_items() --> runs all delayed items from this node and drops the node's item count to 0 through call to btrfs_release_delayed_inode() --> finishes running any remaining delayed nodes --> finishes transaction commit --> stops cleaner and transaction threads btrfs_free_fs_roots() --> frees all roots and removes them from the radix tree fs_info->fs_roots_radix btrfs_join_transaction() start_transaction() btrfs_record_root_in_trans() record_root_in_trans() radix_tree_tag_set() --> crashes because the root is not in the radix tree anymore If the worker is able to call btrfs_join_transaction() before the unmount task frees the fs roots, we end up leaking a transaction and all its resources, since after the call to btrfs_commit_super() and stopping the transaction kthread, we don't expect to have any transaction open anymore. When this situation happens the worker has a delayed node that has no more items to run, since the task calling btrfs_run_delayed_items(), which is doing a transaction commit, picks the same node and runs all its items first. We can not wait for the worker to complete when running delayed items through btrfs_run_delayed_items(), because we call that function in several phases of a transaction commit, and that could cause a deadlock because the worker calls btrfs_join_transaction() and the task doing the transaction commit may have already set the transaction state to TRANS_STATE_COMMIT_DOING. Also it's not possible to get into a situation where only some of the items of a delayed node are added to the fs/subvolume tree in the current transaction and the remaining ones in the next transaction, because when running the items of a delayed inode we lock its mutex, effectively waiting for the worker if the worker is running the items of the delayed node already. Since this can only cause issues when unmounting a filesystem, fix it in a simple way by waiting for any jobs on the delayed workers queue before calling btrfs_commit_supper() at close_ctree(). This works because at this point no one can call btrfs_btree_balance_dirty() or btrfs_balance_delayed_items(), and if we end up waiting for any worker to complete, btrfs_commit_super() will commit the transaction created by the worker. CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 056ad39 upstream. FuzzUSB (a variant of syzkaller) found a free-while-still-in-use bug in the USB scatter-gather library: BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:26 [inline] BUG: KASAN: use-after-free in usb_hcd_unlink_urb+0x5f/0x170 drivers/usb/core/hcd.c:1607 Read of size 4 at addr ffff888065379610 by task kworker/u4:1/27 CPU: 1 PID: 27 Comm: kworker/u4:1 Not tainted 5.5.11 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 Workqueue: scsi_tmf_2 scmd_eh_abort_handler Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xce/0x128 lib/dump_stack.c:118 print_address_description.constprop.4+0x21/0x3c0 mm/kasan/report.c:374 __kasan_report+0x153/0x1cb mm/kasan/report.c:506 kasan_report+0x12/0x20 mm/kasan/common.c:639 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x152/0x1b0 mm/kasan/generic.c:192 __kasan_check_read+0x11/0x20 mm/kasan/common.c:95 atomic_read include/asm-generic/atomic-instrumented.h:26 [inline] usb_hcd_unlink_urb+0x5f/0x170 drivers/usb/core/hcd.c:1607 usb_unlink_urb+0x72/0xb0 drivers/usb/core/urb.c:657 usb_sg_cancel+0x14e/0x290 drivers/usb/core/message.c:602 usb_stor_stop_transport+0x5e/0xa0 drivers/usb/storage/transport.c:937 This bug occurs when cancellation of the S-G transfer races with transfer completion. When that happens, usb_sg_cancel() may continue to access the transfer's URBs after usb_sg_wait() has freed them. The bug is caused by the fact that usb_sg_cancel() does not take any sort of reference to the transfer, and so there is nothing to prevent the URBs from being deallocated while the routine is trying to use them. The fix is to take such a reference by incrementing the transfer's io->count field while the cancellation is in progres and decrementing it afterward. The transfer's URBs are not deallocated until io->complete is triggered, which happens when io->count reaches zero. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-and-tested-by: Kyungtae Kim <kt0755@gmail.com> CC: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/Pine.LNX.4.44L0.2003281615140.14837-100000@netrider.rowland.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 76e7527 ] Some servers seem to accept connections while booting but never send the SMBNegotiate response neither close the connection, causing all processes accessing the share hang on uninterruptible sleep state. This happens when the cifs_demultiplex_thread detects the server is unresponsive so releases the socket and start trying to reconnect. At some point, the faulty server will accept the socket and the TCP status will be set to NeedNegotiate. The first issued command accessing the share will start the negotiation (pid 5828 below), but the response will never arrive so other commands will be blocked waiting on the mutex (pid 55352). This patch checks for unresponsive servers also on the negotiate stage releasing the socket and reconnecting if the response is not received and checking again the tcp state when the mutex is acquired. PID: 55352 TASK: ffff880fd6cc02c0 CPU: 0 COMMAND: "ls" #0 [ffff880fd9add9f0] schedule at ffffffff81467eb9 #1 [ffff880fd9addb38] __mutex_lock_slowpath at ffffffff81468fe0 #2 [ffff880fd9addba8] mutex_lock at ffffffff81468b1a #3 [ffff880fd9addbc0] cifs_reconnect_tcon at ffffffffa042f905 [cifs] #4 [ffff880fd9addc60] smb_init at ffffffffa042faeb [cifs] khadas#5 [ffff880fd9addca0] CIFSSMBQPathInfo at ffffffffa04360b5 [cifs] .... Which is waiting a mutex owned by: PID: 5828 TASK: ffff880fcc55e400 CPU: 0 COMMAND: "xxxx" #0 [ffff880fbfdc19b8] schedule at ffffffff81467eb9 #1 [ffff880fbfdc1b00] wait_for_response at ffffffffa044f96d [cifs] #2 [ffff880fbfdc1b60] SendReceive at ffffffffa04505ce [cifs] #3 [ffff880fbfdc1bb0] CIFSSMBNegotiate at ffffffffa0438d79 [cifs] #4 [ffff880fbfdc1c50] cifs_negotiate_protocol at ffffffffa043b383 [cifs] khadas#5 [ffff880fbfdc1c80] cifs_reconnect_tcon at ffffffffa042f911 [cifs] khadas#6 [ffff880fbfdc1d20] smb_init at ffffffffa042faeb [cifs] khadas#7 [ffff880fbfdc1d60] CIFSSMBQFSInfo at ffffffffa0434eb0 [cifs] .... Signed-off-by: Samuel Cabrero <scabrero@suse.de> Reviewed-by: Aurélien Aptel <aaptel@suse.de> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
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During device unmapping (triggered by module unload or explicit unmap), a refcount underflow occurs causing a use-after-free warning: [14747.574913] ------------[ cut here ]------------ [14747.574916] refcount_t: underflow; use-after-free. [14747.574917] WARNING: lib/refcount.c:28 at refcount_warn_saturate+0x55/0x90, CPU#9: kworker/9:1/378 [14747.574924] Modules linked in: rnbd_client(-) rtrs_client rnbd_server rtrs_server rtrs_core ... [14747.574998] CPU: 9 UID: 0 PID: 378 Comm: kworker/9:1 Tainted: G O N 6.19.0-rc3lblk-fnext+ khadas#42 PREEMPT(voluntary) [14747.575005] Workqueue: rnbd_clt_wq unmap_device_work [rnbd_client] [14747.575010] RIP: 0010:refcount_warn_saturate+0x55/0x90 [14747.575037] Call Trace: [14747.575038] <TASK> [14747.575038] rnbd_clt_unmap_device+0x170/0x1d0 [rnbd_client] [14747.575044] process_one_work+0x211/0x600 [14747.575052] worker_thread+0x184/0x330 [14747.575055] ? __pfx_worker_thread+0x10/0x10 [14747.575058] kthread+0x10d/0x250 [14747.575062] ? __pfx_kthread+0x10/0x10 [14747.575066] ret_from_fork+0x319/0x390 [14747.575069] ? __pfx_kthread+0x10/0x10 [14747.575072] ret_from_fork_asm+0x1a/0x30 [14747.575083] </TASK> [14747.575096] ---[ end trace 0000000000000000 ]--- Befor this patch :- The bug is a double kobject_put() on dev->kobj during device cleanup. Kobject Lifecycle: kobject_init_and_add() sets kobj.kref = 1 (initialization) kobject_put() sets kobj.kref = 0 (should be called once) * Before this patch: rnbd_clt_unmap_device() rnbd_destroy_sysfs() kobject_del(&dev->kobj) [remove from sysfs] kobject_put(&dev->kobj) PUT #1 (WRONG!) kref: 1 to 0 rnbd_dev_release() kfree(dev) [DEVICE FREED!] rnbd_destroy_gen_disk() [use-after-free!] rnbd_clt_put_dev() refcount_dec_and_test(&dev->refcount) kobject_put(&dev->kobj) PUT #2 (UNDERFLOW!) kref: 0 to -1 [WARNING!] The first kobject_put() in rnbd_destroy_sysfs() prematurely frees the device via rnbd_dev_release(), then the second kobject_put() in rnbd_clt_put_dev() causes refcount underflow. * After this patch :- Remove kobject_put() from rnbd_destroy_sysfs(). This function should only remove sysfs visibility (kobject_del), not manage object lifetime. Call Graph (FIXED): rnbd_clt_unmap_device() rnbd_destroy_sysfs() kobject_del(&dev->kobj) [remove from sysfs only] [kref unchanged: 1] rnbd_destroy_gen_disk() [device still valid] rnbd_clt_put_dev() refcount_dec_and_test(&dev->refcount) kobject_put(&dev->kobj) ONLY PUT (CORRECT!) kref: 1 to 0 [BALANCED] rnbd_dev_release() kfree(dev) [CLEAN DESTRUCTION] This follows the kernel pattern where sysfs removal (kobject_del) is separate from object destruction (kobject_put). Fixes: 581cf833cac4 ("block: rnbd: add .release to rnbd_dev_ktype") Signed-off-by: Chaitanya Kulkarni <ckulkarnilinux@gmail.com> Acked-by: Jack Wang <jinpu.wang@ionos.com> Reviewed-by: Jack Wang <jinpu.wang@ionos.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Patch series "mm/hugetlb: fixes for PMD table sharing (incl. using mmu_gather)", v3. One functional fix, one performance regression fix, and two related comment fixes. I cleaned up my prototype I recently shared [1] for the performance fix, deferring most of the cleanups I had in the prototype to a later point. While doing that I identified the other things. The goal of this patch set is to be backported to stable trees "fairly" easily. At least patch #1 and #4. Patch #1 fixes hugetlb_pmd_shared() not detecting any sharing Patch #2 + #3 are simple comment fixes that patch #4 interacts with. Patch #4 is a fix for the reported performance regression due to excessive IPI broadcasts during fork()+exit(). The last patch is all about TLB flushes, IPIs and mmu_gather. Read: complicated There are plenty of cleanups in the future to be had + one reasonable optimization on x86. But that's all out of scope for this series. Runtime tested, with a focus on fixing the performance regression using the original reproducer [2] on x86. This patch (of 4): We switched from (wrongly) using the page count to an independent shared count. Now, shared page tables have a refcount of 1 (excluding speculative references) and instead use ptdesc->pt_share_count to identify sharing. We didn't convert hugetlb_pmd_shared(), so right now, we would never detect a shared PMD table as such, because sharing/unsharing no longer touches the refcount of a PMD table. Page migration, like mbind() or migrate_pages() would allow for migrating folios mapped into such shared PMD tables, even though the folios are not exclusive. In smaps we would account them as "private" although they are "shared", and we would be wrongly setting the PM_MMAP_EXCLUSIVE in the pagemap interface. Fix it by properly using ptdesc_pmd_is_shared() in hugetlb_pmd_shared(). Link: https://lkml.kernel.org/r/20251223214037.580860-1-david@kernel.org Link: https://lkml.kernel.org/r/20251223214037.580860-2-david@kernel.org Link: https://lore.kernel.org/all/8cab934d-4a56-44aa-b641-bfd7e23bd673@kernel.org/ [1] Link: https://lore.kernel.org/all/8cab934d-4a56-44aa-b641-bfd7e23bd673@kernel.org/ [2] Fixes: 59d9094 ("mm: hugetlb: independent PMD page table shared count") Signed-off-by: David Hildenbrand (Red Hat) <david@kernel.org> Reviewed-by: Rik van Riel <riel@surriel.com> Reviewed-by: Lance Yang <lance.yang@linux.dev> Tested-by: Lance Yang <lance.yang@linux.dev> Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Tested-by: Laurence Oberman <loberman@redhat.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Oscar Salvador <osalvador@suse.de> Cc: Liu Shixin <liushixin2@huawei.com> Cc: Uschakow, Stanislav" <suschako@amazon.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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A null-ptr-deref was reported in the SCTP transmit path when SCTP-AUTH key initialization fails: ================================================================== KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] CPU: 0 PID: 16 Comm: ksoftirqd/0 Tainted: G W 6.6.0 #2 RIP: 0010:sctp_packet_bundle_auth net/sctp/output.c:264 [inline] RIP: 0010:sctp_packet_append_chunk+0xb36/0x1260 net/sctp/output.c:401 Call Trace: sctp_packet_transmit_chunk+0x31/0x250 net/sctp/output.c:189 sctp_outq_flush_data+0xa29/0x26d0 net/sctp/outqueue.c:1111 sctp_outq_flush+0xc80/0x1240 net/sctp/outqueue.c:1217 sctp_cmd_interpreter.isra.0+0x19a5/0x62c0 net/sctp/sm_sideeffect.c:1787 sctp_side_effects net/sctp/sm_sideeffect.c:1198 [inline] sctp_do_sm+0x1a3/0x670 net/sctp/sm_sideeffect.c:1169 sctp_assoc_bh_rcv+0x33e/0x640 net/sctp/associola.c:1052 sctp_inq_push+0x1dd/0x280 net/sctp/inqueue.c:88 sctp_rcv+0x11ae/0x3100 net/sctp/input.c:243 sctp6_rcv+0x3d/0x60 net/sctp/ipv6.c:1127 The issue is triggered when sctp_auth_asoc_init_active_key() fails in sctp_sf_do_5_1C_ack() while processing an INIT_ACK. In this case, the command sequence is currently: - SCTP_CMD_PEER_INIT - SCTP_CMD_TIMER_STOP (T1_INIT) - SCTP_CMD_TIMER_START (T1_COOKIE) - SCTP_CMD_NEW_STATE (COOKIE_ECHOED) - SCTP_CMD_ASSOC_SHKEY - SCTP_CMD_GEN_COOKIE_ECHO If SCTP_CMD_ASSOC_SHKEY fails, asoc->shkey remains NULL, while asoc->peer.auth_capable and asoc->peer.peer_chunks have already been set by SCTP_CMD_PEER_INIT. This allows a DATA chunk with auth = 1 and shkey = NULL to be queued by sctp_datamsg_from_user(). Since command interpretation stops on failure, no COOKIE_ECHO should been sent via SCTP_CMD_GEN_COOKIE_ECHO. However, the T1_COOKIE timer has already been started, and it may enqueue a COOKIE_ECHO into the outqueue later. As a result, the DATA chunk can be transmitted together with the COOKIE_ECHO in sctp_outq_flush_data(), leading to the observed issue. Similar to the other places where it calls sctp_auth_asoc_init_active_key() right after sctp_process_init(), this patch moves the SCTP_CMD_ASSOC_SHKEY immediately after SCTP_CMD_PEER_INIT, before stopping T1_INIT and starting T1_COOKIE. This ensures that if shared key generation fails, authenticated DATA cannot be sent. It also allows the T1_INIT timer to retransmit INIT, giving the client another chance to process INIT_ACK and retry key setup. Fixes: 730fc3d ("[SCTP]: Implete SCTP-AUTH parameter processing") Reported-by: Zhen Chen <chenzhen126@huawei.com> Tested-by: Zhen Chen <chenzhen126@huawei.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Link: https://patch.msgid.link/44881224b375aa8853f5e19b4055a1a56d895813.1768324226.git.lucien.xin@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Jamal Hadi Salim says: ==================== net/sched: teql: Enforce hierarchy placement GangMin Kim <km.kim1503@gmail.com> managed to create a UAF on qfq by inserting teql as a child qdisc and exploiting a qlen sync issue. teql is not intended to be used as a child qdisc. Lets enforce that rule in patch #1. Although patch #1 fixes the issue, we prevent another potential qlen exploit in qfq in patch #2 by enforcing the child's active status is not determined by inspecting the qlen. In patch #3 we add a tdc test case. ==================== Link: https://patch.msgid.link/20260114160243.913069-1-jhs@mojatatu.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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…itives The "valid" readout delay between the two reads of the watchdog is larger than the valid delta between the resulting watchdog and clocksource intervals, which results in false positive watchdog results. Assume TSC is the clocksource and HPET is the watchdog and both have a uncertainty margin of 250us (default). The watchdog readout does: 1) wdnow = read(HPET); 2) csnow = read(TSC); 3) wdend = read(HPET); The valid window for the delta between #1 and #3 is calculated by the uncertainty margins of the watchdog and the clocksource: m = 2 * watchdog.uncertainty_margin + cs.uncertainty margin; which results in 750us for the TSC/HPET case. The actual interval comparison uses a smaller margin: m = watchdog.uncertainty_margin + cs.uncertainty margin; which results in 500us for the TSC/HPET case. That means the following scenario will trigger the watchdog: Watchdog cycle N: 1) wdnow[N] = read(HPET); 2) csnow[N] = read(TSC); 3) wdend[N] = read(HPET); Assume the delay between #1 and #2 is 100us and the delay between #1 and Watchdog cycle N + 1: 4) wdnow[N + 1] = read(HPET); 5) csnow[N + 1] = read(TSC); 6) wdend[N + 1] = read(HPET); If the delay between #4 and khadas#6 is within the 750us margin then any delay between #4 and khadas#5 which is larger than 600us will fail the interval check and mark the TSC unstable because the intervals are calculated against the previous value: wd_int = wdnow[N + 1] - wdnow[N]; cs_int = csnow[N + 1] - csnow[N]; Putting the above delays in place this results in: cs_int = (wdnow[N + 1] + 610us) - (wdnow[N] + 100us); -> cs_int = wd_int + 510us; which is obviously larger than the allowed 500us margin and results in marking TSC unstable. Fix this by using the same margin as the interval comparison. If the delay between two watchdog reads is larger than that, then the readout was either disturbed by interconnect congestion, NMIs or SMIs. Fixes: 4ac1dd3 ("clocksource: Set cs_watchdog_read() checks based on .uncertainty_margin") Reported-by: Daniel J Blueman <daniel@quora.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Tested-by: Paul E. McKenney <paulmck@kernel.org> Link: https://lore.kernel.org/lkml/20250602223251.496591-1-daniel@quora.org/ Link: https://patch.msgid.link/87bjjxc9dq.ffs@tglx
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When one iio device is a consumer of another, it is possible that
the ->info_exist_lock of both ends up being taken when reading the
value of the consumer device.
Since they currently belong to the same lockdep class (being
initialized in a single location with mutex_init()), that results in a
lockdep warning
CPU0
----
lock(&iio_dev_opaque->info_exist_lock);
lock(&iio_dev_opaque->info_exist_lock);
*** DEADLOCK ***
May be due to missing lock nesting notation
4 locks held by sensors/414:
#0: c31fd6dc (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0x44/0x4e4
#1: c4f5a1c4 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x1c/0xac
#2: c2827548 (kn->active#34){.+.+}-{0:0}, at: kernfs_seq_start+0x30/0xac
#3: c1dd2b6 (&iio_dev_opaque->info_exist_lock){+.+.}-{3:3}, at: iio_read_channel_processed_scale+0x24/0xd8
stack backtrace:
CPU: 0 UID: 0 PID: 414 Comm: sensors Not tainted 6.17.11 khadas#5 NONE
Hardware name: Generic AM33XX (Flattened Device Tree)
Call trace:
unwind_backtrace from show_stack+0x10/0x14
show_stack from dump_stack_lvl+0x44/0x60
dump_stack_lvl from print_deadlock_bug+0x2b8/0x334
print_deadlock_bug from __lock_acquire+0x13a4/0x2ab0
__lock_acquire from lock_acquire+0xd0/0x2c0
lock_acquire from __mutex_lock+0xa0/0xe8c
__mutex_lock from mutex_lock_nested+0x1c/0x24
mutex_lock_nested from iio_read_channel_raw+0x20/0x6c
iio_read_channel_raw from rescale_read_raw+0x128/0x1c4
rescale_read_raw from iio_channel_read+0xe4/0xf4
iio_channel_read from iio_read_channel_processed_scale+0x6c/0xd8
iio_read_channel_processed_scale from iio_hwmon_read_val+0x68/0xbc
iio_hwmon_read_val from dev_attr_show+0x18/0x48
dev_attr_show from sysfs_kf_seq_show+0x80/0x110
sysfs_kf_seq_show from seq_read_iter+0xdc/0x4e4
seq_read_iter from vfs_read+0x238/0x2e4
vfs_read from ksys_read+0x6c/0xec
ksys_read from ret_fast_syscall+0x0/0x1c
Just as the mlock_key already has its own lockdep class, add a
lock_class_key for the info_exist mutex.
Note that this has in theory been a problem since before IIO first
left staging, but it only occurs when a chain of consumers is in use
and that is not often done.
Fixes: ac917a8 ("staging:iio:core set the iio_dev.info pointer to null on unregister under lock.")
Signed-off-by: Rasmus Villemoes <ravi@prevas.dk>
Reviewed-by: Peter Rosin <peda@axentia.se>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
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Since the commit 25c6a5a ("net: phy: micrel: Dynamically control external clock of KSZ PHY"), the clock of Micrel PHY has been enabled by phy_driver::resume() and disabled by phy_driver::suspend(). However, devm_clk_get_optional_enabled() is used in kszphy_probe(), so the clock will automatically be disabled when the device is unbound from the bus. Therefore, this could cause the clock to be disabled twice, resulting in clk driver warnings. For example, this issue can be reproduced on i.MX6ULL platform, and we can see the following logs when removing the FEC MAC drivers. $ echo 2188000.ethernet > /sys/bus/platform/drivers/fec/unbind $ echo 20b4000.ethernet > /sys/bus/platform/drivers/fec/unbind [ 109.758207] ------------[ cut here ]------------ [ 109.758240] WARNING: drivers/clk/clk.c:1188 at clk_core_disable+0xb4/0xd0, CPU#0: sh/639 [ 109.771011] enet2_ref already disabled [ 109.793359] Call trace: [ 109.822006] clk_core_disable from clk_disable+0x28/0x34 [ 109.827340] clk_disable from clk_disable_unprepare+0xc/0x18 [ 109.833029] clk_disable_unprepare from devm_clk_release+0x1c/0x28 [ 109.839241] devm_clk_release from devres_release_all+0x98/0x100 [ 109.845278] devres_release_all from device_unbind_cleanup+0xc/0x70 [ 109.851571] device_unbind_cleanup from device_release_driver_internal+0x1a4/0x1f4 [ 109.859170] device_release_driver_internal from bus_remove_device+0xbc/0xe4 [ 109.866243] bus_remove_device from device_del+0x140/0x458 [ 109.871757] device_del from phy_mdio_device_remove+0xc/0x24 [ 109.877452] phy_mdio_device_remove from mdiobus_unregister+0x40/0xac [ 109.883918] mdiobus_unregister from fec_enet_mii_remove+0x40/0x78 [ 109.890125] fec_enet_mii_remove from fec_drv_remove+0x4c/0x158 [ 109.896076] fec_drv_remove from device_release_driver_internal+0x17c/0x1f4 [ 109.962748] WARNING: drivers/clk/clk.c:1047 at clk_core_unprepare+0xfc/0x13c, CPU#0: sh/639 [ 109.975805] enet2_ref already unprepared [ 110.002866] Call trace: [ 110.031758] clk_core_unprepare from clk_unprepare+0x24/0x2c [ 110.037440] clk_unprepare from devm_clk_release+0x1c/0x28 [ 110.042957] devm_clk_release from devres_release_all+0x98/0x100 [ 110.048989] devres_release_all from device_unbind_cleanup+0xc/0x70 [ 110.055280] device_unbind_cleanup from device_release_driver_internal+0x1a4/0x1f4 [ 110.062877] device_release_driver_internal from bus_remove_device+0xbc/0xe4 [ 110.069950] bus_remove_device from device_del+0x140/0x458 [ 110.075469] device_del from phy_mdio_device_remove+0xc/0x24 [ 110.081165] phy_mdio_device_remove from mdiobus_unregister+0x40/0xac [ 110.087632] mdiobus_unregister from fec_enet_mii_remove+0x40/0x78 [ 110.093836] fec_enet_mii_remove from fec_drv_remove+0x4c/0x158 [ 110.099782] fec_drv_remove from device_release_driver_internal+0x17c/0x1f4 After analyzing the process of removing the FEC driver, as shown below, it can be seen that the clock was disabled twice by the PHY driver. fec_drv_remove() --> fec_enet_close() --> phy_stop() --> phy_suspend() --> kszphy_suspend() #1 The clock is disabled --> fec_enet_mii_remove() --> mdiobus_unregister() --> phy_mdio_device_remove() --> device_del() --> devm_clk_release() #2 The clock is disabled again Therefore, devm_clk_get_optional() is used to fix the above issue. And to avoid the issue mentioned by the commit 9853294 ("net: phy: micrel: use devm_clk_get_optional_enabled for the rmii-ref clock"), the clock is enabled by clk_prepare_enable() to get the correct clock rate. Fixes: 25c6a5a ("net: phy: micrel: Dynamically control external clock of KSZ PHY") Signed-off-by: Wei Fang <wei.fang@nxp.com> Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com> Link: https://patch.msgid.link/20260126081544.983517-1-wei.fang@nxp.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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…alled from deferred_grow_zone() Commit 3acb913 ("mm/mm_init: use deferred_init_memmap_chunk() in deferred_grow_zone()") made deferred_grow_zone() call deferred_init_memmap_chunk() within a pgdat_resize_lock() critical section with irqs disabled. It did check for irqs_disabled() in deferred_init_memmap_chunk() to avoid calling cond_resched(). For a PREEMPT_RT kernel build, however, spin_lock_irqsave() does not disable interrupt but rcu_read_lock() is called. This leads to the following bug report. BUG: sleeping function called from invalid context at mm/mm_init.c:2091 in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper/0 preempt_count: 0, expected: 0 RCU nest depth: 1, expected: 0 3 locks held by swapper/0/1: #0: ffff80008471b7a0 (sched_domains_mutex){+.+.}-{4:4}, at: sched_domains_mutex_lock+0x28/0x40 #1: ffff003bdfffef48 (&pgdat->node_size_lock){+.+.}-{3:3}, at: deferred_grow_zone+0x140/0x278 #2: ffff800084acf600 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1b4/0x408 CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Tainted: G W 6.19.0-rc6-test #1 PREEMPT_{RT,(full) } Tainted: [W]=WARN Call trace: show_stack+0x20/0x38 (C) dump_stack_lvl+0xdc/0xf8 dump_stack+0x1c/0x28 __might_resched+0x384/0x530 deferred_init_memmap_chunk+0x560/0x688 deferred_grow_zone+0x190/0x278 _deferred_grow_zone+0x18/0x30 get_page_from_freelist+0x780/0xf78 __alloc_frozen_pages_noprof+0x1dc/0x348 alloc_slab_page+0x30/0x110 allocate_slab+0x98/0x2a0 new_slab+0x4c/0x80 ___slab_alloc+0x5a4/0x770 __slab_alloc.constprop.0+0x88/0x1e0 __kmalloc_node_noprof+0x2c0/0x598 __sdt_alloc+0x3b8/0x728 build_sched_domains+0xe0/0x1260 sched_init_domains+0x14c/0x1c8 sched_init_smp+0x9c/0x1d0 kernel_init_freeable+0x218/0x358 kernel_init+0x28/0x208 ret_from_fork+0x10/0x20 Fix it adding a new argument to deferred_init_memmap_chunk() to explicitly tell it if cond_resched() is allowed or not instead of relying on some current state information which may vary depending on the exact kernel configuration options that are enabled. Link: https://lkml.kernel.org/r/20260122184343.546627-1-longman@redhat.com Fixes: 3acb913 ("mm/mm_init: use deferred_init_memmap_chunk() in deferred_grow_zone()") Signed-off-by: Waiman Long <longman@redhat.com> Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: <stable@vger.kernrl.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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There was a lockdep warning in sprd_gpio: [ 6.258269][T329@C6] [ BUG: Invalid wait context ] [ 6.258270][T329@C6] 6.18.0-android17-0-g30527ad7aaae-ab00009-4k #1 Tainted: G W OE [ 6.258272][T329@C6] ----------------------------- [ 6.258273][T329@C6] modprobe/329 is trying to lock: [ 6.258275][T329@C6] ffffff8081c91690 (&sprd_gpio->lock){....}-{3:3}, at: sprd_gpio_irq_unmask+0x4c/0xa4 [gpio_sprd] [ 6.258282][T329@C6] other info that might help us debug this: [ 6.258283][T329@C6] context-{5:5} [ 6.258285][T329@C6] 3 locks held by modprobe/329: [ 6.258286][T329@C6] #0: ffffff808baca108 (&dev->mutex){....}-{4:4}, at: __driver_attach+0xc4/0x204 [ 6.258295][T329@C6] #1: ffffff80965e7240 (request_class#4){+.+.}-{4:4}, at: __setup_irq+0x1cc/0x82c [ 6.258304][T329@C6] #2: ffffff80965e70c8 (lock_class#4){....}-{2:2}, at: __setup_irq+0x21c/0x82c [ 6.258313][T329@C6] stack backtrace: [ 6.258314][T329@C6] CPU: 6 UID: 0 PID: 329 Comm: modprobe Tainted: G W OE 6.18.0-android17-0-g30527ad7aaae-ab00009-4k #1 PREEMPT 3ad5b0f45741a16e5838da790706e16ceb6717df [ 6.258316][T329@C6] Tainted: [W]=WARN, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE [ 6.258317][T329@C6] Hardware name: Unisoc UMS9632-base Board (DT) [ 6.258318][T329@C6] Call trace: [ 6.258318][T329@C6] show_stack+0x20/0x30 (C) [ 6.258321][T329@C6] __dump_stack+0x28/0x3c [ 6.258324][T329@C6] dump_stack_lvl+0xac/0xf0 [ 6.258326][T329@C6] dump_stack+0x18/0x3c [ 6.258329][T329@C6] __lock_acquire+0x824/0x2c28 [ 6.258331][T329@C6] lock_acquire+0x148/0x2cc [ 6.258333][T329@C6] _raw_spin_lock_irqsave+0x6c/0xb4 [ 6.258334][T329@C6] sprd_gpio_irq_unmask+0x4c/0xa4 [gpio_sprd 814535e93c6d8e0853c45c02eab0fa88a9da6487] [ 6.258337][T329@C6] irq_startup+0x238/0x350 [ 6.258340][T329@C6] __setup_irq+0x504/0x82c [ 6.258342][T329@C6] request_threaded_irq+0x118/0x184 [ 6.258344][T329@C6] devm_request_threaded_irq+0x94/0x120 [ 6.258347][T329@C6] sc8546_init_irq+0x114/0x170 [sc8546_charger 223586ccafc27439f7db4f95b0c8e6e882349a99] [ 6.258352][T329@C6] sc8546_charger_probe+0x53c/0x5a0 [sc8546_charger 223586ccafc27439f7db4f95b0c8e6e882349a99] [ 6.258358][T329@C6] i2c_device_probe+0x2c8/0x350 [ 6.258361][T329@C6] really_probe+0x1a8/0x46c [ 6.258363][T329@C6] __driver_probe_device+0xa4/0x10c [ 6.258366][T329@C6] driver_probe_device+0x44/0x1b4 [ 6.258369][T329@C6] __driver_attach+0xd0/0x204 [ 6.258371][T329@C6] bus_for_each_dev+0x10c/0x168 [ 6.258373][T329@C6] driver_attach+0x2c/0x3c [ 6.258376][T329@C6] bus_add_driver+0x154/0x29c [ 6.258378][T329@C6] driver_register+0x70/0x10c [ 6.258381][T329@C6] i2c_register_driver+0x48/0xc8 [ 6.258384][T329@C6] init_module+0x28/0xfd8 [sc8546_charger 223586ccafc27439f7db4f95b0c8e6e882349a99] [ 6.258389][T329@C6] do_one_initcall+0x128/0x42c [ 6.258392][T329@C6] do_init_module+0x60/0x254 [ 6.258395][T329@C6] load_module+0x1054/0x1220 [ 6.258397][T329@C6] __arm64_sys_finit_module+0x240/0x35c [ 6.258400][T329@C6] invoke_syscall+0x60/0xec [ 6.258402][T329@C6] el0_svc_common+0xb0/0xe4 [ 6.258405][T329@C6] do_el0_svc+0x24/0x30 [ 6.258407][T329@C6] el0_svc+0x54/0x1c4 [ 6.258409][T329@C6] el0t_64_sync_handler+0x68/0xdc [ 6.258411][T329@C6] el0t_64_sync+0x1c4/0x1c8 This is because the spin_lock would change to rt_mutex in PREEMPT_RT, however the sprd_gpio->lock would use in hard-irq, this is unsafe. So change the spin_lock_t to raw_spin_lock_t to use the spinlock in hard-irq. Signed-off-by: Xuewen Yan <xuewen.yan@unisoc.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: https://lore.kernel.org/r/20260126094209.9855-1-xuewen.yan@unisoc.com [Bartosz: tweaked the commit message] Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
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