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The main two issues were the timing out of operations due to wrong baudrate (2nd commit) and not finding the UART (3rd commit). Things work reasonably well with this, though I still occasionally see a timeout on the first command, necessitating a re-attach of the tty.

I still see the following error when attaching the tty:

 Bluetooth: hci0: BCM: failed to write update baudrate (-16)   (-EBUSY)

But it is benign, as the UART device does not appear to need its baud rate changed.

Finally, the 4th commit fixes the following two BUG's:

 BUG: sleeping function called from invalid context at kernel/locking/mutex.c
 in_atomic(): 1, irqs_disabled(): 0, pid: 7303, name: kworker/7:3
 INFO: lockdep is turned off.
 CPU: 7 PID: 7303 Comm: kworker/7:3 Tainted: G        W  OE   4.13.2+ #17
 Hardware name: Apple Inc. MacBookPro13,3/Mac-A5C67F76ED83108C, BIOS MBP133.8
 Workqueue: events hci_uart_write_work [hci_uart]
 Call Trace:
  dump_stack+0x8e/0xd6
  ___might_sleep+0x164/0x250
  __might_sleep+0x4a/0x80
  __mutex_lock+0x59/0xa00
  ? lock_acquire+0xa3/0x1f0
  ? lock_acquire+0xa3/0x1f0
  ? hci_uart_write_work+0xd3/0x160 [hci_uart]
  mutex_lock_nested+0x1b/0x20
  ? mutex_lock_nested+0x1b/0x20
  bcm_dequeue+0x21/0xc0 [hci_uart]
  hci_uart_write_work+0xe6/0x160 [hci_uart]
  process_one_work+0x253/0x6a0
  worker_thread+0x4d/0x3b0
  kthread+0x133/0x150
  ? process_one_work+0x6a0/0x6a0
  ? kthread_create_on_node+0x70/0x70
  ret_from_fork+0x2a/0x40

 BUG: sleeping function called from invalid context at kernel/locking/mutex.c
 in_atomic(): 1, irqs_disabled(): 0, pid: 13796, name: kworker/u16:2
 INFO: lockdep is turned off.
 CPU: 1 PID: 13796 Comm: kworker/u16:2 Tainted: G        W  OE   4.13.2+ #17
 Hardware name: Apple Inc. MacBookPro13,3/Mac-A5C67F76ED83108C, BIOS MBP133.8
 Workqueue: events_unbound flush_to_ldisc
 Call Trace:
  dump_stack+0x8e/0xd6
  ___might_sleep+0x164/0x250
  __might_sleep+0x4a/0x80
  __mutex_lock+0x59/0xa00
  ? trace_hardirqs_on+0xd/0x10
  ? hci_recv_frame+0x68/0xa0 [bluetooth]
  ? h4_recv_buf+0x17a/0x2f0 [hci_uart]
  mutex_lock_nested+0x1b/0x20
  ? mutex_lock_nested+0x1b/0x20
  bcm_recv+0x73/0x130 [hci_uart]
  hci_uart_tty_receive+0x61/0xa0 [hci_uart]
  tty_ldisc_receive_buf+0x48/0x50
  tty_port_default_receive_buf+0x49/0x70
  flush_to_ldisc+0x83/0xa0
  process_one_work+0x253/0x6a0
  worker_thread+0x4d/0x3b0
  kthread+0x133/0x150
  ? process_one_work+0x6a0/0x6a0
  ? kthread_create_on_node+0x70/0x70
  ret_from_fork+0x2a/0x40

The methods are supposed to return 0 on success, and the flag to enable
low-power operation was inverted.

Signed-off-by: Ronald Tschalär <ronald@innovation.ch>
The device must be accessed via the configured baudrate for all
operations, or the operations will time out.

Note that currently bcm_set_baudrate() always fails (the commands always
return -EBUSY) and hence the operating baudrate is never actually set.
But if it were, it would need to be the same as the init baudrate, so
we keep setting oper_speed anyway.

Signed-off-by: Ronald Tschalär <ronald@innovation.ch>
When the UART is part of an intel-lpss based mfd, the resulting device
tree has an extra level. Specifically we have the following layout (with
the /sys/devices/ prefix removed for brevity):

  ACPI device node:
    LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:94/BCM2E7C:00
  Associated physical device node:
    LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:94/BCM2E7C:00/physical_node -> pci0000:00/0000:00:1e.0/BCM2E7C:00/
  UART device node:
    pci0000:00/0000:00:1e.0/dw-apb-uart.2
  UART TTY device node:
    pci0000:00/0000:00:1e.0/dw-apb-uart.2/tty

This driver was assuming that physical device's parent is the UART, but
in this case the parent is the mfd device. We therefore check for both
cases.

Note that because this assumption appears in some user-space tools too,
it might be better to put the physical device node under the UART
instead of the mfd.

Signed-off-by: Ronald Tschalär <ronald@innovation.ch>
Commit dec2c92 introduced locks around
the proto functions, using rwlock's, which do not allow sleeping while
the locks are held. However, the proto functions in hci_bcm use mutexes
and hence need to be able to sleep.

Therefore this replaces the rwlock's with rw_semaphore's. Because the
writes are very rare compared to the reads the percpu variant is used.

Lastly, the locks in the tx_wakeup callback needed to be removed because
that is called from an IRQ context. But since it doesn't actually call
any proto functions, instead just queueing work, and the
HCI_UART_PROTO_READY flag is checked (again) in the worker, this doesn't
cause any problems.

Signed-off-by: Ronald Tschalär <ronald@innovation.ch>
roadrunner2 referenced this pull request in roadrunner2/linux Sep 24, 2017
commit 55acdd9 upstream.

Can be reproduced when running dlm_controld (tested on 4.4.x, 4.12.4):
 # seq 1 100 | xargs -P0 -n1 dlm_tool join
 # seq 1 100 | xargs -P0 -n1 dlm_tool leave

misc_register fails due to duplicate sysfs entry, which causes
dlm_device_register to free ls->ls_device.name.
In dlm_device_deregister the name was freed again, causing memory
corruption.

According to the comment in dlm_device_deregister the name should've been
set to NULL when registration fails,
so this patch does that.

sysfs: cannot create duplicate filename '/dev/char/10:1'
------------[ cut here ]------------
warning: cpu: 1 pid: 4450 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x56/0x70
modules linked in: msr rfcomm dlm ccm bnep dm_crypt uvcvideo
videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_core videodev
btusb media btrtl btbcm btintel bluetooth ecdh_generic intel_rapl
x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm
snd_hda_codec_hdmi irqbypass crct10dif_pclmul crc32_pclmul
ghash_clmulni_intel thinkpad_acpi pcbc nvram snd_seq_midi
snd_seq_midi_event aesni_intel snd_hda_codec_realtek snd_hda_codec_generic
snd_rawmidi aes_x86_64 crypto_simd glue_helper snd_hda_intel snd_hda_codec
cryptd intel_cstate arc4 snd_hda_core snd_seq snd_seq_device snd_hwdep
iwldvm intel_rapl_perf mac80211 joydev input_leds iwlwifi serio_raw
cfg80211 snd_pcm shpchp snd_timer snd mac_hid mei_me lpc_ich mei soundcore
sunrpc parport_pc ppdev lp parport autofs4 i915 psmouse
 e1000e ahci libahci i2c_algo_bit sdhci_pci ptp drm_kms_helper sdhci
pps_core syscopyarea sysfillrect sysimgblt fb_sys_fops drm wmi video
cpu: 1 pid: 4450 comm: dlm_test.exe not tainted 4.12.4-041204-generic
hardware name: lenovo 232425u/232425u, bios g2et82ww (2.02 ) 09/11/2012
task: ffff96b0cbabe140 task.stack: ffffb199027d0000
rip: 0010:sysfs_warn_dup+0x56/0x70
rsp: 0018:ffffb199027d3c58 eflags: 00010282
rax: 0000000000000038 rbx: ffff96b0e2c49158 rcx: 0000000000000006
rdx: 0000000000000000 rsi: 0000000000000086 rdi: ffff96b15e24dcc0
rbp: ffffb199027d3c70 r08: 0000000000000001 r09: 0000000000000721
r10: ffffb199027d3c00 r11: 0000000000000721 r12: ffffb199027d3cd1
r13: ffff96b1592088f0 r14: 0000000000000001 r15: ffffffffffffffef
fs:  00007f78069c0700(0000) gs:ffff96b15e240000(0000)
knlgs:0000000000000000
cs:  0010 ds: 0000 es: 0000 cr0: 0000000080050033
cr2: 000000178625ed28 cr3: 0000000091d3e000 cr4: 00000000001406e0
call trace:
 sysfs_do_create_link_sd.isra.2+0x9e/0xb0
 sysfs_create_link+0x25/0x40
 device_add+0x5a9/0x640
 device_create_groups_vargs+0xe0/0xf0
 device_create_with_groups+0x3f/0x60
 ? snprintf+0x45/0x70
 misc_register+0x140/0x180
 device_write+0x6a8/0x790 [dlm]
 __vfs_write+0x37/0x160
 ? apparmor_file_permission+0x1a/0x20
 ? security_file_permission+0x3b/0xc0
 vfs_write+0xb5/0x1a0
 sys_write+0x55/0xc0
 ? sys_fcntl+0x5d/0xb0
 entry_syscall_64_fastpath+0x1e/0xa9
rip: 0033:0x7f78083454bd
rsp: 002b:00007f78069bbd30 eflags: 00000293 orig_rax: 0000000000000001
rax: ffffffffffffffda rbx: 0000000000000006 rcx: 00007f78083454bd
rdx: 000000000000009c rsi: 00007f78069bee00 rdi: 0000000000000005
rbp: 00007f77f8000a20 r08: 000000000000fcf0 r09: 0000000000000032
r10: 0000000000000024 r11: 0000000000000293 r12: 00007f78069bde00
r13: 00007f78069bee00 r14: 000000000000000a r15: 00007f78069bbd70
code: 85 c0 48 89 c3 74 12 b9 00 10 00 00 48 89 c2 31 f6 4c 89 ef e8 2c c8
ff ff 4c 89 e2 48 89 de 48 c7 c7 b0 8e 0c a8 e8 41 e8 ed ff <0f> ff 48 89
df e8 00 d5 f4 ff 5b 41 5c 41 5d 5d c3 66 0f 1f 84
---[ end trace 40412246357cc9e0 ]---

dlm: 59f24629-ae39-44e2-9030-397ebc2eda26: leaving the lockspace group...
bug: unable to handle kernel null pointer dereference at 0000000000000001
ip: [<ffffffff811a3b4a>] kmem_cache_alloc+0x7a/0x140
pgd 0
oops: 0000 [#1] smp
modules linked in: dlm 8021q garp mrp stp llc openvswitch nf_defrag_ipv6
nf_conntrack libcrc32c iptable_filter dm_multipath crc32_pclmul dm_mod
aesni_intel psmouse aes_x86_64 sg ablk_helper cryptd lrw gf128mul
glue_helper i2c_piix4 nls_utf8 tpm_tis tpm isofs nfsd auth_rpcgss
oid_registry nfs_acl lockd grace sunrpc xen_wdt ip_tables x_tables autofs4
hid_generic usbhid hid sr_mod cdrom sd_mod ata_generic pata_acpi 8139too
serio_raw ata_piix 8139cp mii uhci_hcd ehci_pci ehci_hcd libata
scsi_dh_rdac scsi_dh_hp_sw scsi_dh_emc scsi_dh_alua scsi_mod ipv6
cpu: 0 pid: 394 comm: systemd-udevd tainted: g w 4.4.0+0 #1
hardware name: xen hvm domu, bios 4.7.2-2.2 05/11/2017
task: ffff880002410000 ti: ffff88000243c000 task.ti: ffff88000243c000
rip: e030:[<ffffffff811a3b4a>] [<ffffffff811a3b4a>]
kmem_cache_alloc+0x7a/0x140
rsp: e02b:ffff88000243fd90 eflags: 00010202
rax: 0000000000000000 rbx: ffff8800029864d0 rcx: 000000000007b36c
rdx: 000000000007b36b rsi: 00000000024000c0 rdi: ffff880036801c00
rbp: ffff88000243fdc0 r08: 0000000000018880 r09: 0000000000000054
r10: 000000000000004a r11: ffff880034ace6c0 r12: 00000000024000c0
r13: ffff880036801c00 r14: 0000000000000001 r15: ffffffff8118dcc2
fs: 00007f0ab77548c0(0000) gs:ffff880036e00000(0000) knlgs:0000000000000000
cs: e033 ds: 0000 es: 0000 cr0: 0000000080050033
cr2: 0000000000000001 cr3: 000000000332d000 cr4: 0000000000040660
stack:
ffffffff8118dc90 ffff8800029864d0 0000000000000000 ffff88003430b0b0
ffff880034b78320 ffff88003430b0b0 ffff88000243fdf8 ffffffff8118dcc2
ffff8800349c6700 ffff8800029864d0 000000000000000b 00007f0ab7754b90
call trace:
[<ffffffff8118dc90>] ? anon_vma_fork+0x60/0x140
[<ffffffff8118dcc2>] anon_vma_fork+0x92/0x140
[<ffffffff8107033e>] copy_process+0xcae/0x1a80
[<ffffffff8107128b>] _do_fork+0x8b/0x2d0
[<ffffffff81071579>] sys_clone+0x19/0x20
[<ffffffff815a30ae>] entry_syscall_64_fastpath+0x12/0x71
] code: f6 75 1c 4c 89 fa 44 89 e6 4c 89 ef e8 a7 e4 00 00 41 f7 c4 00 80
00 00 49 89 c6 74 47 eb 32 49 63 45 20 48 8d 4a 01 4d 8b 45 00 <49> 8b 1c
06 4c 89 f0 65 49 0f c7 08 0f 94 c0 84 c0 74 ac 49 63
rip [<ffffffff811a3b4a>] kmem_cache_alloc+0x7a/0x140
rsp <ffff88000243fd90>
cr2: 0000000000000001
--[ end trace 70cb9fd1b164a0e8 ]--

Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
@l1k
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l1k commented Sep 25, 2017

Great job @roadrunner2!

As to the first commit, the schematics of the MB8,1 call the line BT_LOW_PWR_L, so it's active low apparently. And BTLP(1) sets the output value to 0. Hence I'm surprised that the value needs to be inverted. What's the behavior without this change, does it not work or consume more power?

D'accord on the botched ACPI_SUCCESS() check.

The occasional timeout on the first command sounds like a delay may be needed in bcm_apple_set_power() and/or bcm_apple_set_device_wake(). However looking at IOBluetoothHostControllerUARTTransport.kext in the disassembler I notice that it doesn't wait after calling the ACPI methods, it just carries on immediately. Still might be worth a try.

As to the second commit, could you check where the -EBUSY is coming from? In __hci_cmd_sync_ev(), I suppose hdev->req_status == HCI_REQ_DONE, so the -EBUSY is coming directly from the device, right? If you change the if (speed > 3000000) check to >=, do you still get the same error? If you do, maybe the device refuses to set the baudrate and the meaning of the baud device property is thus that it is a fixed speed that cannot be changed.

The other two commits I need to take a closer look.

@roadrunner2
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@l1k Regarding the schematics etc, that looks correct: BTLP(1) puts the device into low power - see also the DSDT snippet I posted. The issue is that bcm_apple_set_device_wake() gets called with enable false when going to sleep, and with enable true when waking up. Ergo enable == false => BLTP(1) and enable == true => BLTP(0). Unless I'm totally confused.

In any case I haven't actually tested suspend and resume yet - I just noticed the issue while looking at the code.

Regarding EBUSY: I already tried adding up to 100ms delay after power up, but that didn't help. And I traced the EBUSY down to getting the bluetooth status code 0x0c (which gets translated to EBUSY by bt_to_errno()) in hci_req_cmd_complete(), called either by hci_cmd_complete_evt() or hci_cmd_status_evt(). I'll try to trace it further back in a few days.

@l1k
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l1k commented Oct 7, 2017

The issue is that bcm_apple_set_device_wake() gets called with enable false when going to sleep, and with enable true when waking up. Ergo enable == false => BLTP(1) and enable == true => BLTP(0). Unless I'm totally confused.

Okay, thanks for the explanation. Apparently the inverse polarity of the pin is open coded in this driver, which is crap, normally this is declared in the platform firmware.

Anyway, the hci_bcm driver is being migrated to the new serial device bus, i.e. there is no tty chardev anymore for the UART, invocation of hciattach is no longer necessary and the kernel automatically switches to N_HCI ldisc and probes the hci_bcm driver. This also solves the issue addressed by your third patch in this pull. An initial set of 9 patches by Hans de Goede was merged to bluetooth-next a day ago and there are 2 other patches needed by Frédéric Danis which are unmerged yet but are slated for merging via the ACPI subsystem. Johan Hovold came up with a few comments and objections today but nothing that can't be resolved. I'm in the process of rebasing onto these patches, actually I've just done that but I need to review and refine a little further and will likely push the new branch on Monday. Thanks for your patience.

@l1k
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l1k commented Oct 9, 2017

So I've pushed the hci_bcm_v1 branch today as an initial attempt to rebase on current bluetooth-next. Compile-tested only as I don't have the hardware. Be sure to enable CONFIG_SERIAL_DEV_BUS, CONFIG_SERIAL_DEV_CTRL_TTYPORT and CONFIG_BT_HCIUART_SERDEV to test this. Note that bcm_probe() is dead code now, only bcm_serdev_probe() is relevant.

@l1k
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l1k commented Oct 10, 2017

Frédéric Danis posted a v2 of his patches so I rebased the hci_bcm_v1 branch on top of them. Sorry, we're shooting at a moving target here.

@l1k
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l1k commented Oct 11, 2017

Another day, another rebase. This is now based on Frédéric Danis' v3 plus a fix by Johan Hovold, all on top of current bluetooth-next.

@roadrunner2
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😃 I'll give it a whirl in the next couple days.

One thing I was wondering: should the proto-locks patch be pushed for 4.14? I honestly don't see how this can be working at all, unless nobody is using hci_bcm or I'm missing something basic.

roadrunner2 referenced this pull request in roadrunner2/linux Oct 12, 2017
…() returns

The cgroup_taskset structure within the larger cgroup_mgctx structure
is supposed to be used once and then discarded. That is not really the
case in the hotplug code path:

cpuset_hotplug_workfn()
 - cgroup_transfer_tasks()
   - cgroup_migrate()
     - cgroup_migrate_add_task()
     - cgroup_migrate_execute()

In this case, the cgroup_migrate() function is called multiple time
with the same cgroup_mgctx structure to transfer the tasks from
one cgroup to another one-by-one. The second time cgroup_migrate()
is called, the cgroup_taskset will be in an incorrect state and so
may cause the system to panic. For example,

  [  150.888410] Faulting instruction address: 0xc0000000001db648
  [  150.888414] Oops: Kernel access of bad area, sig: 11 [#1]
  [  150.888417] SMP NR_CPUS=2048
  [  150.888417] NUMA
  [  150.888419] pSeries
    :
  [  150.888545] NIP [c0000000001db648] cpuset_can_attach+0x58/0x1b0
  [  150.888548] LR [c0000000001db638] cpuset_can_attach+0x48/0x1b0
  [  150.888551] Call Trace:
  [  150.888554] [c0000005f65cb940] [c0000000001db638] cpuset_can_attach+0x48/0x1b 0 (unreliable)
  [  150.888559] [c0000005f65cb9a0] [c0000000001cff04] cgroup_migrate_execute+0xc4/0x4b0
  [  150.888563] [c0000005f65cba20] [c0000000001d7d14] cgroup_transfer_tasks+0x1d4/0x370
  [  150.888568] [c0000005f65cbb70] [c0000000001ddcb0] cpuset_hotplug_workfn+0x710/0x8f0
  [  150.888572] [c0000005f65cbc80] [c00000000012032c] process_one_work+0x1ac/0x4d0
  [  150.888576] [c0000005f65cbd20] [c0000000001206f8] worker_thread+0xa8/0x5b0
  [  150.888580] [c0000005f65cbdc0] [c0000000001293f8] kthread+0x168/0x1b0
  [  150.888584] [c0000005f65cbe30] [c00000000000b368] ret_from_kernel_thread+0x5c/0x74

To allow reuse of the cgroup_mgctx structure, some fields in that
structure are now re-initialized at the end of cgroup_migrate_execute()
function call so that the structure can be reused again in a later
iteration without causing problem.

This bug was introduced in the commit e595cd7 ("group: track
migration context in cgroup_mgctx") in 4.11. This commit moves the
cgroup_taskset initialization out of cgroup_migrate(). The commit
10467270fb3 ("cgroup: don't call migration methods if there are no
tasks to migrate") helped, but did not completely resolve the problem.

Fixes: e595cd7 ("group: track migration context in cgroup_mgctx")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org # v4.11+
roadrunner2 referenced this pull request in roadrunner2/linux Oct 12, 2017
Xiaolong reported a suspicious rcu_dereference_check in the device
unregister notifier callback. Since we do not dereference the
rx_handler_data, it's ok to just check for the value of the pointer.
Note that this section is already protected by rtnl_lock.

[  101.364846] WARNING: suspicious RCU usage
[  101.365654] 4.13.0-rc6-01701-gceed73a #1 Not tainted
[  101.370873] -----------------------------
[  101.372472] drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c:57 suspicious rcu_dereference_check() usage!
[  101.374427]
[  101.374427] other info that might help us debug this:
[  101.374427]
[  101.387491]
[  101.387491] rcu_scheduler_active = 2, debug_locks = 1
[  101.389368] 1 lock held by trinity-main/2809:
[  101.390736]  #0:  (rtnl_mutex){+.+.+.}, at: [<8146085b>] rtnl_lock+0xf/0x11
[  101.395482]
[  101.395482] stack backtrace:
[  101.396948] CPU: 0 PID: 2809 Comm: trinity-main Not tainted 4.13.0-rc6-01701-gceed73a #1
[  101.398857] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.3-20161025_171302-gandalf 04/01/2014
[  101.401079] Call Trace:
[  101.401656]  dump_stack+0xa1/0xeb
[  101.402871]  lockdep_rcu_suspicious+0xc7/0xd0
[  101.403665]  rmnet_is_real_dev_registered+0x40/0x4e
[  101.405199]  rmnet_config_notify_cb+0x2c/0x142
[  101.406344]  ? wireless_nlevent_flush+0x47/0x71
[  101.407385]  notifier_call_chain+0x2d/0x47
[  101.408645]  raw_notifier_call_chain+0xc/0xe
[  101.409882]  call_netdevice_notifiers_info+0x41/0x49
[  101.411402]  call_netdevice_notifiers+0xc/0xe
[  101.412713]  rollback_registered_many+0x268/0x36e
[  101.413702]  rollback_registered+0x39/0x56
[  101.414965]  unregister_netdevice_queue+0x79/0x88
[  101.415908]  unregister_netdev+0x16/0x1d

Fixes: ceed73a ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation")
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Reported-by: kernel test robot <xiaolong.ye@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
roadrunner2 referenced this pull request in roadrunner2/linux Oct 12, 2017
The driver calls spi_get_drvdata() in its ->remove hook even though it
has never called spi_set_drvdata().  Stack trace for posterity:

Unable to handle kernel NULL pointer dereference at virtual address 00000220
Internal error: Oops: 5 [#1] SMP ARM
[<8072f564>] (mutex_lock) from [<7f1400d0>] (iio_device_unregister+0x24/0x7c [industrialio])
[<7f1400d0>] (iio_device_unregister [industrialio]) from [<7f15e020>] (mcp320x_remove+0x20/0x30 [mcp320x])
[<7f15e020>] (mcp320x_remove [mcp320x]) from [<8055a8cc>] (spi_drv_remove+0x2c/0x44)
[<8055a8cc>] (spi_drv_remove) from [<805087bc>] (__device_release_driver+0x98/0x134)
[<805087bc>] (__device_release_driver) from [<80509180>] (driver_detach+0xdc/0xe0)
[<80509180>] (driver_detach) from [<8050823c>] (bus_remove_driver+0x5c/0xb0)
[<8050823c>] (bus_remove_driver) from [<80509ab0>] (driver_unregister+0x38/0x58)
[<80509ab0>] (driver_unregister) from [<7f15e69c>] (mcp320x_driver_exit+0x14/0x1c [mcp320x])
[<7f15e69c>] (mcp320x_driver_exit [mcp320x]) from [<801a78d0>] (SyS_delete_module+0x184/0x1d0)
[<801a78d0>] (SyS_delete_module) from [<80108100>] (ret_fast_syscall+0x0/0x1c)

Fixes: f5ce4a7 ("iio: adc: add driver for MCP3204/08 12-bit ADC")
Cc: Oskar Andero <oskar.andero@gmail.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
roadrunner2 referenced this pull request in roadrunner2/linux Oct 12, 2017
Because keyctl_read_key() looks up the key with no permissions
requested, it may find a negatively instantiated key.  If the key is
also possessed, we went ahead and called ->read() on the key.  But the
key payload will actually contain the ->reject_error rather than the
normal payload.  Thus, the kernel oopses trying to read the
user_key_payload from memory address (int)-ENOKEY = 0x00000000ffffff82.

Fortunately the payload data is stored inline, so it shouldn't be
possible to abuse this as an arbitrary memory read primitive...

Reproducer:
    keyctl new_session
    keyctl request2 user desc '' @s
    keyctl read $(keyctl show | awk '/user: desc/ {print $1}')

It causes a crash like the following:
     BUG: unable to handle kernel paging request at 00000000ffffff92
     IP: user_read+0x33/0xa0
     PGD 36a54067 P4D 36a54067 PUD 0
     Oops: 0000 [#1] SMP
     CPU: 0 PID: 211 Comm: keyctl Not tainted 4.14.0-rc1 torvalds#337
     Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-20170228_101828-anatol 04/01/2014
     task: ffff90aa3b74c3c0 task.stack: ffff9878c0478000
     RIP: 0010:user_read+0x33/0xa0
     RSP: 0018:ffff9878c047bee8 EFLAGS: 00010246
     RAX: 0000000000000001 RBX: ffff90aa3d7da340 RCX: 0000000000000017
     RDX: 0000000000000000 RSI: 00000000ffffff82 RDI: ffff90aa3d7da340
     RBP: ffff9878c047bf00 R08: 00000024f95da94f R09: 0000000000000000
     R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
     R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
     FS:  00007f58ece69740(0000) GS:ffff90aa3e200000(0000) knlGS:0000000000000000
     CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
     CR2: 00000000ffffff92 CR3: 0000000036adc001 CR4: 00000000003606f0
     Call Trace:
      keyctl_read_key+0xac/0xe0
      SyS_keyctl+0x99/0x120
      entry_SYSCALL_64_fastpath+0x1f/0xbe
     RIP: 0033:0x7f58ec787bb9
     RSP: 002b:00007ffc8d401678 EFLAGS: 00000206 ORIG_RAX: 00000000000000fa
     RAX: ffffffffffffffda RBX: 00007ffc8d402800 RCX: 00007f58ec787bb9
     RDX: 0000000000000000 RSI: 00000000174a63ac RDI: 000000000000000b
     RBP: 0000000000000004 R08: 00007ffc8d402809 R09: 0000000000000020
     R10: 0000000000000000 R11: 0000000000000206 R12: 00007ffc8d402800
     R13: 00007ffc8d4016e0 R14: 0000000000000000 R15: 0000000000000000
     Code: e5 41 55 49 89 f5 41 54 49 89 d4 53 48 89 fb e8 a4 b4 ad ff 85 c0 74 09 80 3d b9 4c 96 00 00 74 43 48 8b b3 20 01 00 00 4d 85 ed <0f> b7 5e 10 74 29 4d 85 e4 74 24 4c 39 e3 4c 89 e2 4c 89 ef 48
     RIP: user_read+0x33/0xa0 RSP: ffff9878c047bee8
     CR2: 00000000ffffff92

Fixes: 61ea0c0 ("KEYS: Skip key state checks when checking for possession")
Cc: <stable@vger.kernel.org>	[v3.13+]
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
roadrunner2 referenced this pull request in roadrunner2/linux Oct 12, 2017
…rse nlmsg properly

ChunYu found a kernel crash by syzkaller:

[  651.617875] kasan: CONFIG_KASAN_INLINE enabled
[  651.618217] kasan: GPF could be caused by NULL-ptr deref or user memory access
[  651.618731] general protection fault: 0000 [#1] SMP KASAN
[  651.621543] CPU: 1 PID: 9539 Comm: scsi Not tainted 4.11.0.cov torvalds#32
[  651.621938] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
[  651.622309] task: ffff880117780000 task.stack: ffff8800a3188000
[  651.622762] RIP: 0010:skb_release_data+0x26c/0x590
[...]
[  651.627260] Call Trace:
[  651.629156]  skb_release_all+0x4f/0x60
[  651.629450]  consume_skb+0x1a5/0x600
[  651.630705]  netlink_unicast+0x505/0x720
[  651.632345]  netlink_sendmsg+0xab2/0xe70
[  651.633704]  sock_sendmsg+0xcf/0x110
[  651.633942]  ___sys_sendmsg+0x833/0x980
[  651.637117]  __sys_sendmsg+0xf3/0x240
[  651.638820]  SyS_sendmsg+0x32/0x50
[  651.639048]  entry_SYSCALL_64_fastpath+0x1f/0xc2

It's caused by skb_shared_info at the end of sk_buff was overwritten by
ISCSI_KEVENT_IF_ERROR when parsing nlmsg info from skb in iscsi_if_rx.

During the loop if skb->len == nlh->nlmsg_len and both are sizeof(*nlh),
ev = nlmsg_data(nlh) will acutally get skb_shinfo(SKB) instead and set a
new value to skb_shinfo(SKB)->nr_frags by ev->type.

This patch is to fix it by checking nlh->nlmsg_len properly there to
avoid over accessing sk_buff.

Reported-by: ChunYu Wang <chunwang@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Chris Leech <cleech@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
roadrunner2 referenced this pull request in roadrunner2/linux Oct 12, 2017
Guillaume Nault says:

====================
l2tp: fix some races in session deletion

L2TP provides several interfaces for deleting sessions. Using two of
them concurrently can lead to use-after-free bugs.

Patch l1k#2 uses a flag to prevent double removal of L2TP sessions.
Patch #1 fixes a bug found in the way. Fixing this bug is also
necessary for patch l1k#2 to handle all cases.

This issue is similar to the tunnel deletion bug being worked on by
Sabrina: https://patchwork.ozlabs.org/patch/814173/
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
roadrunner2 referenced this pull request in roadrunner2/linux Oct 12, 2017
ti-cpufreq and cpufreq-dt-platdev drivers are registering platform-device
with same name "cpufreq-dt" using platform_device_register_*() routines.
This is leading to build warnings appended below.

Providing hardware information to OPP framework along with the platform-
device creation should be done by ti-cpufreq driver before cpufreq-dt
driver comes into place.

This patch add's TI am33xx, am43 and dra7 platforms (which use opp-v2
property) to the blacklist of devices in cpufreq-dt-platform driver to
avoid creating platform-device twice and remove build warnings.

[    2.370167] ------------[ cut here ]------------
[    2.375087] WARNING: CPU: 0 PID: 1 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x58/0x78
[    2.383112] sysfs: cannot create duplicate filename '/devices/platform/cpufreq-dt'
[    2.391219] Modules linked in:
[    2.394506] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.13.0-next-20170912 #1
[    2.402006] Hardware name: Generic AM33XX (Flattened Device Tree)
[    2.408437] [<c0110a28>] (unwind_backtrace) from [<c010ca84>] (show_stack+0x10/0x14)
[    2.416568] [<c010ca84>] (show_stack) from [<c0827d64>] (dump_stack+0xac/0xe0)
[    2.424165] [<c0827d64>] (dump_stack) from [<c0137470>] (__warn+0xd8/0x104)
[    2.431488] [<c0137470>] (__warn) from [<c01374d0>] (warn_slowpath_fmt+0x34/0x44)
[    2.439351] [<c01374d0>] (warn_slowpath_fmt) from [<c03459d0>] (sysfs_warn_dup+0x58/0x78)
[    2.447938] [<c03459d0>] (sysfs_warn_dup) from [<c0345ab8>] (sysfs_create_dir_ns+0x80/0x98)
[    2.456719] [<c0345ab8>] (sysfs_create_dir_ns) from [<c082c554>] (kobject_add_internal+0x9c/0x2d4)
[    2.466124] [<c082c554>] (kobject_add_internal) from [<c082c7d8>] (kobject_add+0x4c/0x9c)
[    2.474712] [<c082c7d8>] (kobject_add) from [<c05803e4>] (device_add+0xcc/0x57c)
[    2.482489] [<c05803e4>] (device_add) from [<c0584b74>] (platform_device_add+0x100/0x220)
[    2.491085] [<c0584b74>] (platform_device_add) from [<c05855a8>] (platform_device_register_full+0xf4/0x118)
[    2.501305] [<c05855a8>] (platform_device_register_full) from [<c067023c>] (ti_cpufreq_init+0x150/0x22c)
[    2.511253] [<c067023c>] (ti_cpufreq_init) from [<c0101df4>] (do_one_initcall+0x3c/0x170)
[    2.519838] [<c0101df4>] (do_one_initcall) from [<c0c00eb4>] (kernel_init_freeable+0x1fc/0x2c4)
[    2.528974] [<c0c00eb4>] (kernel_init_freeable) from [<c083bcac>] (kernel_init+0x8/0x110)
[    2.537565] [<c083bcac>] (kernel_init) from [<c0107d18>] (ret_from_fork+0x14/0x3c)
[    2.545981] ---[ end trace 2fc00e213c13ab20 ]---
[    2.551051] ------------[ cut here ]------------
[    2.555931] WARNING: CPU: 0 PID: 1 at lib/kobject.c:240 kobject_add_internal+0x254/0x2d4
[    2.564578] kobject_add_internal failed for cpufreq-dt with -EEXIST, don't try to register
things with the same name in the same directory.
[    2.577977] Modules linked in:
[    2.581261] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G        W       4.13.0-next-20170912 #1
[    2.590013] Hardware name: Generic AM33XX (Flattened Device Tree)
[    2.596437] [<c0110a28>] (unwind_backtrace) from [<c010ca84>] (show_stack+0x10/0x14)
[    2.604573] [<c010ca84>] (show_stack) from [<c0827d64>] (dump_stack+0xac/0xe0)
[    2.612172] [<c0827d64>] (dump_stack) from [<c0137470>] (__warn+0xd8/0x104)
[    2.619494] [<c0137470>] (__warn) from [<c01374d0>] (warn_slowpath_fmt+0x34/0x44)
[    2.627362] [<c01374d0>] (warn_slowpath_fmt) from [<c082c70c>] (kobject_add_internal+0x254/0x2d4)
[    2.636666] [<c082c70c>] (kobject_add_internal) from [<c082c7d8>] (kobject_add+0x4c/0x9c)
[    2.645255] [<c082c7d8>] (kobject_add) from [<c05803e4>] (device_add+0xcc/0x57c)
[    2.653027] [<c05803e4>] (device_add) from [<c0584b74>] (platform_device_add+0x100/0x220)
[    2.661615] [<c0584b74>] (platform_device_add) from [<c05855a8>] (platform_device_register_full+0xf4/0x118)
[    2.671833] [<c05855a8>] (platform_device_register_full) from [<c067023c>] (ti_cpufreq_init+0x150/0x22c)
[    2.681779] [<c067023c>] (ti_cpufreq_init) from [<c0101df4>] (do_one_initcall+0x3c/0x170)
[    2.690377] [<c0101df4>] (do_one_initcall) from [<c0c00eb4>] (kernel_init_freeable+0x1fc/0x2c4)
[    2.699510] [<c0c00eb4>] (kernel_init_freeable) from [<c083bcac>] (kernel_init+0x8/0x110)
[    2.708106] [<c083bcac>] (kernel_init) from [<c0107d18>] (ret_from_fork+0x14/0x3c)
[    2.716217] ---[ end trace 2fc00e213c13ab21 ]---

Fixes: edeec42 (cpufreq: dt-cpufreq: platdev Automatically create device with OPP v2)
Signed-off-by: Suniel Mahesh <sunil.m@techveda.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
roadrunner2 referenced this pull request in roadrunner2/linux Oct 12, 2017
The ARM short descriptor has already limited the physical address
to 32bit after the commit <76557391433c> ("iommu/io-pgtable: Sanitise
map/unmap addresses"). But in MediaTek 4GB mode, the physical address
is from 0x1_0000_0000 to 0x1_ffff_ffff. this will cause:

WARNING: CPU: 4 PID: 3900 at
xxx/drivers/iommu/io-pgtable-arm-v7s.c:482 arm_v7s_map+0x40/0xf8
Modules linked in:

CPU: 4 PID: 3900 Comm: weston Tainted: G S      W       4.9.44 #1
Hardware name: MediaTek MT2712m1v1 board (DT)
task: ffffffc0eaa5b280 task.stack: ffffffc0e9858000
PC is at arm_v7s_map+0x40/0xf8
LR is at mtk_iommu_map+0x64/0x90
pc : [<ffffff80085b09e8>] lr : [<ffffff80085b29fc>] pstate: 000001c5
sp : ffffffc0e985b920
x29: ffffffc0e985b920 x28: 0000000127d00000
x27: 0000000000100000 x26: ffffff8008f9e000
x25: 0000000000000003 x24: 0000000000100000
x23: 0000000127d00000 x22: 00000000ff800000
x21: ffffffc0f7ec8ce0 x20: 0000000000000003
x19: 0000000000000003 x18: 0000000000000002
x17: 0000007f7e5d72c0 x16: ffffff80082b0f08
x15: 0000000000000001 x14: 000000000000003f
x13: 0000000000000000 x12: 0000000000000028
x11: 0088000000000000 x10: 0000000000000000
x9 : ffffff80092fa000 x8 : ffffffc0e9858000
x7 : ffffff80085b29d8 x6 : 0000000000000000
x5 : ffffff80085b09a8 x4 : 0000000000000003
x3 : 0000000000100000 x2 : 0000000127d00000
x1 : 00000000ff800000 x0 : 0000000000000001
...
Call trace:
[<ffffff80085b09e8>] arm_v7s_map+0x40/0xf8
[<ffffff80085b29fc>] mtk_iommu_map+0x64/0x90
[<ffffff80085ab5f8>] iommu_map+0x100/0x3a0
[<ffffff80085ab99c>] default_iommu_map_sg+0x104/0x168
[<ffffff80085aead8>] iommu_dma_alloc+0x238/0x3f8
[<ffffff8008098b30>] __iommu_alloc_attrs+0xa8/0x260
[<ffffff80085f364c>] mtk_drm_gem_create+0xac/0x180
[<ffffff80085f3894>] mtk_drm_gem_dumb_create+0x54/0xc8
[<ffffff80085d576c>] drm_mode_create_dumb_ioctl+0xa4/0xd8
[<ffffff80085cb2a0>] drm_ioctl+0x1c0/0x490

In order to satify this, Limit the physical address to 32bit.

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
roadrunner2 referenced this pull request in roadrunner2/linux Oct 12, 2017
…ping

When bootup a PVM guest with large memory(Ex.240GB), XEN provided initial
mapping overlaps with kernel module virtual space. When mapping in this space
is cleared by xen_cleanhighmap(), in certain case there could be an 2MB mapping
left. This is due to XEN initialize 4MB aligned mapping but xen_cleanhighmap()
finish at 2MB boundary.

When module loading is just on top of the 2MB space, got below warning:

WARNING: at mm/vmalloc.c:106 vmap_pte_range+0x14e/0x190()
Call Trace:
 [<ffffffff81117083>] warn_alloc_failed+0xf3/0x160
 [<ffffffff81146022>] __vmalloc_area_node+0x182/0x1c0
 [<ffffffff810ac91e>] ? module_alloc_update_bounds+0x1e/0x80
 [<ffffffff81145df7>] __vmalloc_node_range+0xa7/0x110
 [<ffffffff810ac91e>] ? module_alloc_update_bounds+0x1e/0x80
 [<ffffffff8103ca54>] module_alloc+0x64/0x70
 [<ffffffff810ac91e>] ? module_alloc_update_bounds+0x1e/0x80
 [<ffffffff810ac91e>] module_alloc_update_bounds+0x1e/0x80
 [<ffffffff810ac9a7>] move_module+0x27/0x150
 [<ffffffff810aefa0>] layout_and_allocate+0x120/0x1b0
 [<ffffffff810af0a8>] load_module+0x78/0x640
 [<ffffffff811ff90b>] ? security_file_permission+0x8b/0x90
 [<ffffffff810af6d2>] sys_init_module+0x62/0x1e0
 [<ffffffff815154c2>] system_call_fastpath+0x16/0x1b

Then the mapping of 2MB is cleared, finally oops when the page in that space is
accessed.

BUG: unable to handle kernel paging request at ffff880022600000
IP: [<ffffffff81260877>] clear_page_c_e+0x7/0x10
PGD 1788067 PUD 178c067 PMD 22434067 PTE 0
Oops: 0002 [#1] SMP
Call Trace:
 [<ffffffff81116ef7>] ? prep_new_page+0x127/0x1c0
 [<ffffffff81117d42>] get_page_from_freelist+0x1e2/0x550
 [<ffffffff81133010>] ? ii_iovec_copy_to_user+0x90/0x140
 [<ffffffff81119c9d>] __alloc_pages_nodemask+0x12d/0x230
 [<ffffffff81155516>] alloc_pages_vma+0xc6/0x1a0
 [<ffffffff81006ffd>] ? pte_mfn_to_pfn+0x7d/0x100
 [<ffffffff81134cfb>] do_anonymous_page+0x16b/0x350
 [<ffffffff81139c34>] handle_pte_fault+0x1e4/0x200
 [<ffffffff8100712e>] ? xen_pmd_val+0xe/0x10
 [<ffffffff810052c9>] ? __raw_callee_save_xen_pmd_val+0x11/0x1e
 [<ffffffff81139dab>] handle_mm_fault+0x15b/0x270
 [<ffffffff81510c10>] do_page_fault+0x140/0x470
 [<ffffffff8150d7d5>] page_fault+0x25/0x30

Call xen_cleanhighmap() with 4MB aligned for page tables mapping to fix it.
The unnecessory call of xen_cleanhighmap() in DEBUG mode is also removed.

-v2: add comment about XEN alignment from Juergen.

References: https://lists.xen.org/archives/html/xen-devel/2012-07/msg01562.html
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>

[boris: added 'xen/mmu' tag to commit subject]
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
roadrunner2 referenced this pull request in roadrunner2/linux Oct 12, 2017
We currently route pte translation faults via do_page_fault, which elides
the address check against TASK_SIZE before invoking the mm fault handling
code. However, this can cause issues with the path walking code in
conjunction with our word-at-a-time implementation because
load_unaligned_zeropad can end up faulting in kernel space if it reads
across a page boundary and runs into a page fault (e.g. by attempting to
read from a guard region).

In the case of such a fault, load_unaligned_zeropad has registered a
fixup to shift the valid data and pad with zeroes, however the abort is
reported as a level 3 translation fault and we dispatch it straight to
do_page_fault, despite it being a kernel address. This results in calling
a sleeping function from atomic context:

  BUG: sleeping function called from invalid context at arch/arm64/mm/fault.c:313
  in_atomic(): 0, irqs_disabled(): 0, pid: 10290
  Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
  [...]
  [<ffffff8e016cd0cc>] ___might_sleep+0x134/0x144
  [<ffffff8e016cd158>] __might_sleep+0x7c/0x8c
  [<ffffff8e016977f0>] do_page_fault+0x140/0x330
  [<ffffff8e01681328>] do_mem_abort+0x54/0xb0
  Exception stack(0xfffffffb20247a70 to 0xfffffffb20247ba0)
  [...]
  [<ffffff8e016844fc>] el1_da+0x18/0x78
  [<ffffff8e017f399c>] path_parentat+0x44/0x88
  [<ffffff8e017f4c9c>] filename_parentat+0x5c/0xd8
  [<ffffff8e017f5044>] filename_create+0x4c/0x128
  [<ffffff8e017f59e4>] SyS_mkdirat+0x50/0xc8
  [<ffffff8e01684e30>] el0_svc_naked+0x24/0x28
  Code: 36380080 d5384100 f9400800 9402566d (d4210000)
  ---[ end trace 2d01889f2bca9b9f ]---

Fix this by dispatching all translation faults to do_translation_faults,
which avoids invoking the page fault logic for faults on kernel addresses.

Cc: <stable@vger.kernel.org>
Reported-by: Ankit Jain <ankijain@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
roadrunner2 referenced this pull request in roadrunner2/linux Oct 12, 2017
The following lockdep splat has been noticed during LTP testing

  ======================================================
  WARNING: possible circular locking dependency detected
  4.13.0-rc3-next-20170807 torvalds#12 Not tainted
  ------------------------------------------------------
  a.out/4771 is trying to acquire lock:
   (cpu_hotplug_lock.rw_sem){++++++}, at: [<ffffffff812b4668>] drain_all_stock.part.35+0x18/0x140

  but task is already holding lock:
   (&mm->mmap_sem){++++++}, at: [<ffffffff8106eb35>] __do_page_fault+0x175/0x530

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> l1k#3 (&mm->mmap_sem){++++++}:
         lock_acquire+0xc9/0x230
         __might_fault+0x70/0xa0
         _copy_to_user+0x23/0x70
         filldir+0xa7/0x110
         xfs_dir2_sf_getdents.isra.10+0x20c/0x2c0 [xfs]
         xfs_readdir+0x1fa/0x2c0 [xfs]
         xfs_file_readdir+0x30/0x40 [xfs]
         iterate_dir+0x17a/0x1a0
         SyS_getdents+0xb0/0x160
         entry_SYSCALL_64_fastpath+0x1f/0xbe

  -> l1k#2 (&type->i_mutex_dir_key#3){++++++}:
         lock_acquire+0xc9/0x230
         down_read+0x51/0xb0
         lookup_slow+0xde/0x210
         walk_component+0x160/0x250
         link_path_walk+0x1a6/0x610
         path_openat+0xe4/0xd50
         do_filp_open+0x91/0x100
         file_open_name+0xf5/0x130
         filp_open+0x33/0x50
         kernel_read_file_from_path+0x39/0x80
         _request_firmware+0x39f/0x880
         request_firmware_direct+0x37/0x50
         request_microcode_fw+0x64/0xe0
         reload_store+0xf7/0x180
         dev_attr_store+0x18/0x30
         sysfs_kf_write+0x44/0x60
         kernfs_fop_write+0x113/0x1a0
         __vfs_write+0x37/0x170
         vfs_write+0xc7/0x1c0
         SyS_write+0x58/0xc0
         do_syscall_64+0x6c/0x1f0
         return_from_SYSCALL_64+0x0/0x7a

  -> #1 (microcode_mutex){+.+.+.}:
         lock_acquire+0xc9/0x230
         __mutex_lock+0x88/0x960
         mutex_lock_nested+0x1b/0x20
         microcode_init+0xbb/0x208
         do_one_initcall+0x51/0x1a9
         kernel_init_freeable+0x208/0x2a7
         kernel_init+0xe/0x104
         ret_from_fork+0x2a/0x40

  -> #0 (cpu_hotplug_lock.rw_sem){++++++}:
         __lock_acquire+0x153c/0x1550
         lock_acquire+0xc9/0x230
         cpus_read_lock+0x4b/0x90
         drain_all_stock.part.35+0x18/0x140
         try_charge+0x3ab/0x6e0
         mem_cgroup_try_charge+0x7f/0x2c0
         shmem_getpage_gfp+0x25f/0x1050
         shmem_fault+0x96/0x200
         __do_fault+0x1e/0xa0
         __handle_mm_fault+0x9c3/0xe00
         handle_mm_fault+0x16e/0x380
         __do_page_fault+0x24a/0x530
         do_page_fault+0x30/0x80
         page_fault+0x28/0x30

  other info that might help us debug this:

  Chain exists of:
    cpu_hotplug_lock.rw_sem --> &type->i_mutex_dir_key#3 --> &mm->mmap_sem

   Possible unsafe locking scenario:

         CPU0                    CPU1
         ----                    ----
    lock(&mm->mmap_sem);
                                 lock(&type->i_mutex_dir_key#3);
                                 lock(&mm->mmap_sem);
    lock(cpu_hotplug_lock.rw_sem);

   *** DEADLOCK ***

  2 locks held by a.out/4771:
   #0:  (&mm->mmap_sem){++++++}, at: [<ffffffff8106eb35>] __do_page_fault+0x175/0x530
   #1:  (percpu_charge_mutex){+.+...}, at: [<ffffffff812b4c97>] try_charge+0x397/0x6e0

The problem is very similar to the one fixed by commit a459eeb
("mm, page_alloc: do not depend on cpu hotplug locks inside the
allocator").  We are taking hotplug locks while we can be sitting on top
of basically arbitrary locks.  This just calls for problems.

We can get rid of {get,put}_online_cpus, fortunately.  We do not have to
be worried about races with memory hotplug because drain_local_stock,
which is called from both the WQ draining and the memory hotplug
contexts, is always operating on the local cpu stock with IRQs disabled.

The only thing to be careful about is that the target memcg doesn't
vanish while we are still in drain_all_stock so take a reference on it.

Link: http://lkml.kernel.org/r/20170913090023.28322-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Artem Savkov <asavkov@redhat.com>
Tested-by: Artem Savkov <asavkov@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
roadrunner2 referenced this pull request in roadrunner2/linux Oct 12, 2017
printk_ratelimit() invokes ___ratelimit() which may invoke a normal
printk() (pr_warn() in this particular case) to warn about suppressed
output.  Given that printk_ratelimit() may be called from anywhere, that
pr_warn() is dangerous - it may end up deadlocking the system.  Fix
___ratelimit() by using deferred printk().

Sasha reported the following lockdep error:

 : Unregister pv shared memory for cpu 8
 : select_fallback_rq: 3 callbacks suppressed
 : process 8583 (trinity-c78) no longer affine to cpu8
 :
 : ======================================================
 : WARNING: possible circular locking dependency detected
 : 4.14.0-rc2-next-20170927+ torvalds#252 Not tainted
 : ------------------------------------------------------
 : migration/8/62 is trying to acquire lock:
 : (&port_lock_key){-.-.}, at: serial8250_console_write()
 :
 : but task is already holding lock:
 : (&rq->lock){-.-.}, at: sched_cpu_dying()
 :
 : which lock already depends on the new lock.
 :
 :
 : the existing dependency chain (in reverse order) is:
 :
 : -> l1k#3 (&rq->lock){-.-.}:
 : __lock_acquire()
 : lock_acquire()
 : _raw_spin_lock()
 : task_fork_fair()
 : sched_fork()
 : copy_process.part.31()
 : _do_fork()
 : kernel_thread()
 : rest_init()
 : start_kernel()
 : x86_64_start_reservations()
 : x86_64_start_kernel()
 : verify_cpu()
 :
 : -> l1k#2 (&p->pi_lock){-.-.}:
 : __lock_acquire()
 : lock_acquire()
 : _raw_spin_lock_irqsave()
 : try_to_wake_up()
 : default_wake_function()
 : woken_wake_function()
 : __wake_up_common()
 : __wake_up_common_lock()
 : __wake_up()
 : tty_wakeup()
 : tty_port_default_wakeup()
 : tty_port_tty_wakeup()
 : uart_write_wakeup()
 : serial8250_tx_chars()
 : serial8250_handle_irq.part.25()
 : serial8250_default_handle_irq()
 : serial8250_interrupt()
 : __handle_irq_event_percpu()
 : handle_irq_event_percpu()
 : handle_irq_event()
 : handle_level_irq()
 : handle_irq()
 : do_IRQ()
 : ret_from_intr()
 : native_safe_halt()
 : default_idle()
 : arch_cpu_idle()
 : default_idle_call()
 : do_idle()
 : cpu_startup_entry()
 : rest_init()
 : start_kernel()
 : x86_64_start_reservations()
 : x86_64_start_kernel()
 : verify_cpu()
 :
 : -> #1 (&tty->write_wait){-.-.}:
 : __lock_acquire()
 : lock_acquire()
 : _raw_spin_lock_irqsave()
 : __wake_up_common_lock()
 : __wake_up()
 : tty_wakeup()
 : tty_port_default_wakeup()
 : tty_port_tty_wakeup()
 : uart_write_wakeup()
 : serial8250_tx_chars()
 : serial8250_handle_irq.part.25()
 : serial8250_default_handle_irq()
 : serial8250_interrupt()
 : __handle_irq_event_percpu()
 : handle_irq_event_percpu()
 : handle_irq_event()
 : handle_level_irq()
 : handle_irq()
 : do_IRQ()
 : ret_from_intr()
 : native_safe_halt()
 : default_idle()
 : arch_cpu_idle()
 : default_idle_call()
 : do_idle()
 : cpu_startup_entry()
 : rest_init()
 : start_kernel()
 : x86_64_start_reservations()
 : x86_64_start_kernel()
 : verify_cpu()
 :
 : -> #0 (&port_lock_key){-.-.}:
 : check_prev_add()
 : __lock_acquire()
 : lock_acquire()
 : _raw_spin_lock_irqsave()
 : serial8250_console_write()
 : univ8250_console_write()
 : console_unlock()
 : vprintk_emit()
 : vprintk_default()
 : vprintk_func()
 : printk()
 : ___ratelimit()
 : __printk_ratelimit()
 : select_fallback_rq()
 : sched_cpu_dying()
 : cpuhp_invoke_callback()
 : take_cpu_down()
 : multi_cpu_stop()
 : cpu_stopper_thread()
 : smpboot_thread_fn()
 : kthread()
 : ret_from_fork()
 :
 : other info that might help us debug this:
 :
 : Chain exists of:
 :   &port_lock_key --> &p->pi_lock --> &rq->lock
 :
 :  Possible unsafe locking scenario:
 :
 :        CPU0                    CPU1
 :        ----                    ----
 :   lock(&rq->lock);
 :                                lock(&p->pi_lock);
 :                                lock(&rq->lock);
 :   lock(&port_lock_key);
 :
 :  *** DEADLOCK ***
 :
 : 4 locks held by migration/8/62:
 : #0: (&p->pi_lock){-.-.}, at: sched_cpu_dying()
 : #1: (&rq->lock){-.-.}, at: sched_cpu_dying()
 : l1k#2: (printk_ratelimit_state.lock){....}, at: ___ratelimit()
 : l1k#3: (console_lock){+.+.}, at: vprintk_emit()
 :
 : stack backtrace:
 : CPU: 8 PID: 62 Comm: migration/8 Not tainted 4.14.0-rc2-next-20170927+ torvalds#252
 : Call Trace:
 : dump_stack()
 : print_circular_bug()
 : check_prev_add()
 : ? add_lock_to_list.isra.26()
 : ? check_usage()
 : ? kvm_clock_read()
 : ? kvm_sched_clock_read()
 : ? sched_clock()
 : ? check_preemption_disabled()
 : __lock_acquire()
 : ? __lock_acquire()
 : ? add_lock_to_list.isra.26()
 : ? debug_check_no_locks_freed()
 : ? memcpy()
 : lock_acquire()
 : ? serial8250_console_write()
 : _raw_spin_lock_irqsave()
 : ? serial8250_console_write()
 : serial8250_console_write()
 : ? serial8250_start_tx()
 : ? lock_acquire()
 : ? memcpy()
 : univ8250_console_write()
 : console_unlock()
 : ? __down_trylock_console_sem()
 : vprintk_emit()
 : vprintk_default()
 : vprintk_func()
 : printk()
 : ? show_regs_print_info()
 : ? lock_acquire()
 : ___ratelimit()
 : __printk_ratelimit()
 : select_fallback_rq()
 : sched_cpu_dying()
 : ? sched_cpu_starting()
 : ? rcutree_dying_cpu()
 : ? sched_cpu_starting()
 : cpuhp_invoke_callback()
 : ? cpu_disable_common()
 : take_cpu_down()
 : ? trace_hardirqs_off_caller()
 : ? cpuhp_invoke_callback()
 : multi_cpu_stop()
 : ? __this_cpu_preempt_check()
 : ? cpu_stop_queue_work()
 : cpu_stopper_thread()
 : ? cpu_stop_create()
 : smpboot_thread_fn()
 : ? sort_range()
 : ? schedule()
 : ? __kthread_parkme()
 : kthread()
 : ? sort_range()
 : ? kthread_create_on_node()
 : ret_from_fork()
 : process 9121 (trinity-c78) no longer affine to cpu8
 : smpboot: CPU 8 is now offline

Link: http://lkml.kernel.org/r/20170928120405.18273-1-sergey.senozhatsky@gmail.com
Fixes: 6b1d174 ("ratelimit: extend to print suppressed messages on release")
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reported-by: Sasha Levin <levinsasha928@gmail.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Borislav Petkov <bp@suse.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
roadrunner2 referenced this pull request in roadrunner2/linux Oct 12, 2017
flush_tlb_kernel_range() may call smp_call_function_many() which expects
interrupts to be enabled. This results in a traceback.

WARNING: CPU: 0 PID: 1 at kernel/smp.c:416 smp_call_function_many+0xcc/0x2fc
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.14.0-rc1-00009-g0666f56 #1
task: cf830000 task.stack: cf82e000
NIP:  c00a93c8 LR: c00a9634 CTR: 00000001
REGS: cf82fde0 TRAP: 0700   Not tainted  (4.14.0-rc1-00009-g0666f56)
MSR:  00021000 <CE,ME>  CR: 24000082  XER: 00000000

GPR00: c00a9634 cf82fe90 cf830000 c050ad3c c0015a54 00000000 00000001 00000001
GPR08: 00000001 00000000 00000000 cf82e000 24000084 00000000 c0003150 00000000
GPR16: 00000000 00000000 00000000 00000000 00000000 00000001 00000000 c051000
GPR24: 00000000 c0015a54 00000000 c050ad3c c051823c c050ad3c 00000025 00000000
NIP [c00a93c8] smp_call_function_many+0xcc/0x2fc
LR [c00a9634] smp_call_function+0x3c/0x50
Call Trace:
[cf82fe90] [00000010] 0x10 (unreliable)
[cf82fed0] [c00a9634] smp_call_function+0x3c/0x50
[cf82fee0] [c0015d2] flush_tlb_kernel_range+0x20/0x38
[cf82fef0] [c001524c] mark_initmem_nx+0x154/0x16c
[cf82ff20] [c001484c] free_initmem+0x20/0x4c
[cf82ff30] [c000316c] kernel_init+0x1c/0x108
[cf82ff40] [c000f3a8] ret_from_kernel_thread+0x5c/0x64
Instruction dump:
7c0803a6 7d808120 38210040 4e800020 3d20c052 812981a0 2f890000 40beffac
3d20c051 8929ac64 2f890000 40beff9c <0fe00000> 4bffff94 7fc3f378 7f64db78

Fixes: 3184cc4 ("powerpc/mm: Fix kernel RAM protection after freeing ...")
Fixes: e611939 ("powerpc/mm: Ensure change_page_attr() doesn't ...")
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
@roadrunner2
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It works! 🎉 Device got automatically attached. Great work!

FYI here is all related dmesg output:

[    3.194718] dw-apb-uart.1: ttyS4 at MMIO 0x8272a000 (irq = 21, base_baud = 115200) is a 16550A
[    3.195152] serial serial0: tty port ttyS4 registered
[    3.211904] dw-apb-uart.2: ttyS5 at MMIO 0x8272b000 (irq = 20, base_baud = 3000000) is a 16550A
[    3.212244] serial serial1: tty port ttyS5 registered
[    3.227479] dw-apb-uart.3: ttyS6 at MMIO 0x8272c000 (irq = 21, base_baud = 115200) is a 16550A
[    3.227751] serial serial2: tty port ttyS6 registered
[    9.123026] SELinux:  Class bluetooth_socket not defined in policy.
[   10.180684] synth uevent: /devices/pci0000:00/0000:00:19.0/dw-apb-uart.1/serial0: failed to send uevent
[   10.182831] synth uevent: /devices/pci0000:00/0000:00:1e.0/dw-apb-uart.2/serial1: failed to send uevent
[   10.183808] synth uevent: /devices/pci0000:00/0000:00:1e.1/dw-apb-uart.3/serial2: failed to send uevent
[   10.404890] Bluetooth: Core ver 2.22
[   10.404993] Bluetooth: HCI device and connection manager initialized
[   10.405122] Bluetooth: HCI socket layer initialized
[   10.405132] Bluetooth: L2CAP socket layer initialized
[   10.405236] Bluetooth: SCO socket layer initialized
[   10.435054] Bluetooth: HCI UART driver ver 2.3
[   10.435061] Bluetooth: HCI UART protocol H4 registered
[   10.435066] Bluetooth: HCI UART protocol BCSP registered
[   10.435196] Bluetooth: HCI UART protocol LL registered
[   10.435200] Bluetooth: HCI UART protocol ATH3K registered
[   10.435203] Bluetooth: HCI UART protocol Three-wire (H5) registered
[   10.441639] Bluetooth: HCI UART protocol Intel registered
[   10.441848] Bluetooth: HCI UART protocol Broadcom registered
[   10.441853] Bluetooth: HCI UART protocol QCA registered
[   10.441857] Bluetooth: HCI UART protocol AG6XX registered
[   10.441862] Bluetooth: HCI UART protocol Marvell registered
[   10.442029] hci_uart_bcm serial1-0: BCM irq: -22
[   10.455816] dw-apb-uart dw-apb-uart.2: Looking for DMA channel "rx" at index 1...
[   10.455926] ttyS5 - failed to request DMA
[   10.715458] Bluetooth: hci0: BCM: failed to write update baudrate (-16)
[   10.715471] Bluetooth: hci0: failed to set baudrate
[   10.827304] Bluetooth: hci0: BCM: chip id 126
[   10.828714] Bluetooth: hci0: BCM: features 0x2f
[   10.837984] Bluetooth: hci0: BCM20703A2 Generic UART UHE Apple 40MHz wlcsp_x100
[   10.837990] Bluetooth: hci0: BCM (001.002.048) build 0131
[   10.838214] bluetooth hci0: Direct firmware load for brcm/BCM.hcd failed with error -2
[   10.838235] Bluetooth: hci0: BCM: Patch brcm/BCM.hcd not found
[   13.743577] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[   13.743581] Bluetooth: BNEP filters: protocol multicast
[   13.743587] Bluetooth: BNEP socket layer initialized
[   24.114250] Bluetooth: RFCOMM TTY layer initialized
[   24.114263] Bluetooth: RFCOMM socket layer initialized
[   24.114315] Bluetooth: RFCOMM ver 1.11

@peterychuang
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I can confirm the patches work on the latest linux-next tree. Thanks for your work!

PS @l1k if you don't mind, could you change my cc email in the commit to peteryuchuang at gmail dot com? Thanks.

@l1k
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l1k commented Oct 13, 2017

Thanks a lot for testing! I'll have to do a bit more code reading and analysis of @roadrunner2's dmesg output to finalize the patch. The issue that a timeout occurs, does this still exist? With serdev, you can no longer stop and restart hciattach to work around it...

@roadrunner2: About the proto-locks patch: I've realized only now that hci_ldisc.c is apparently no longer used in favor of hci_serdev.c. Since the patch changes the former, it seems it's not really necessary. The legacy code which uses a line discipline to signify that a Bluetooth device is attached currently coexists with the newer serdev code, it's quite a mess and I'm having trouble wrapping my head around it myself. The good news is that hci_bcm seems to be the first driver converted to the new infrastructure and we can piggyback on this effort and avoid trouble with a later conversion to serdev.

I can't really connect the proto-locks patch with the stacktraces you've posted above: They refer to a struct mutex, which is indeed a sleeping lock that can't be used in atomic/interrupt context, but the patch changes an rwlock_t, so a different locking primitive.

So, looking at the second stacktrace, we can see that mutex_lock() was called from bcm_recv(). There is some stuff about hci_recv_frame() and h4_recv_buf() above that but it looks bogus. Sometimes stacktraces contain garbage like that, the new ORC unwinder is said to be more reliable. But anyway, if I look at bcm_recv(), there's indeed a call to mutex_lock() there which is invoked if h4_recv_buf() returned NULL. So the question is, why did it return NULL? Was that correct in the given situation? And the BUG occurred because in_atomic() was true at that point. Hmmm, no idea if there's an actual bug here or if this was an issue with the rc kernel that I had based the hci_bcm branch on, or something else entirely...

@peterychuang: Sure, I've updated your e-mail address and pushed the branch, again rebased on current bluetooth-next.

@roadrunner2
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@l1k Regarding the locking: the mutex is in hci_bcm, so lower down in call chain; the rwlock (which doesn't allow sleeping) is acquired in hci_ldisc, which is higher up in the call chain. More specifically: hci_uart_tty_receive and hci_uart_write_work both acquire the rwlock - those entries in the stack trace are real ones (well, hci_uart_write_lock inlines hci_uart_dequeue which is the one actually taking the lock and calling down to proto->dequeue). With the rwlock held, both of these then call down to the respective proto callbacks, which in this case are bcm_recv and bcm_dequeue. And those two directly acquire the mutex.

Regarding h4_recv_buf returning null, that appears to signal a complete frame - see comment near the bottom of that function. In any case, even if that would be bug (though since bcm_recv explicitly tests for this case, I think it's very much intentional), the write (dequeue) path has the same locking issue.

Now, AFAICT we can't replace the mutex in hci_bcm with something non-sleeping, so we have to change the rwlock instead to something that allows sleeping - that is a more general fix anyway (i.e. allows any proto implementation to use any lock it wants).

I looked at hci_serdev and that doesn't have this issue because it doesn't do any locking itself.

So for bluetooth-next it appears the lock patch isn't strictly necessary, but for 4.14?

Lastly, regarding the timeout, no, haven't seen it yet, but haven't done much testing - will bang at it some more and let you know.

l1k pushed a commit that referenced this pull request May 6, 2025
[BUG]
There is a bug report that a syzbot reproducer can lead to the following
busy inode at unmount time:

  BTRFS info (device loop1): last unmount of filesystem 1680000e-3c1e-4c46-84b6-56bd3909af50
  VFS: Busy inodes after unmount of loop1 (btrfs)
  ------------[ cut here ]------------
  kernel BUG at fs/super.c:650!
  Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
  CPU: 0 UID: 0 PID: 48168 Comm: syz-executor Not tainted 6.15.0-rc2-00471-g119009db2674 #2 PREEMPT(full)
  Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
  RIP: 0010:generic_shutdown_super+0x2e9/0x390 fs/super.c:650
  Call Trace:
   <TASK>
   kill_anon_super+0x3a/0x60 fs/super.c:1237
   btrfs_kill_super+0x3b/0x50 fs/btrfs/super.c:2099
   deactivate_locked_super+0xbe/0x1a0 fs/super.c:473
   deactivate_super fs/super.c:506 [inline]
   deactivate_super+0xe2/0x100 fs/super.c:502
   cleanup_mnt+0x21f/0x440 fs/namespace.c:1435
   task_work_run+0x14d/0x240 kernel/task_work.c:227
   resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
   exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
   exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
   __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
   syscall_exit_to_user_mode+0x269/0x290 kernel/entry/common.c:218
   do_syscall_64+0xd4/0x250 arch/x86/entry/syscall_64.c:100
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
   </TASK>

[CAUSE]
When btrfs_alloc_path() failed, btrfs_iget() directly returned without
releasing the inode already allocated by btrfs_iget_locked().

This results the above busy inode and trigger the kernel BUG.

[FIX]
Fix it by calling iget_failed() if btrfs_alloc_path() failed.

If we hit error inside btrfs_read_locked_inode(), it will properly call
iget_failed(), so nothing to worry about.

Although the iget_failed() cleanup inside btrfs_read_locked_inode() is a
break of the normal error handling scheme, let's fix the obvious bug
and backport first, then rework the error handling later.

Reported-by: Penglei Jiang <superman.xpt@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/20250421102425.44431-1-superman.xpt@gmail.com/
Fixes: 7c855e1 ("btrfs: remove conditional path allocation in btrfs_read_locked_inode()")
CC: stable@vger.kernel.org # 6.13+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Penglei Jiang <superman.xpt@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
l1k pushed a commit that referenced this pull request May 6, 2025
A BUG was reported as below when CONFIG_DEBUG_ATOMIC_SLEEP and
try_verify_in_tasklet are enabled.
[  129.444685][  T934] BUG: sleeping function called from invalid context at drivers/md/dm-bufio.c:2421
[  129.444723][  T934] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 934, name: kworker/1:4
[  129.444740][  T934] preempt_count: 201, expected: 0
[  129.444756][  T934] RCU nest depth: 0, expected: 0
[  129.444781][  T934] Preemption disabled at:
[  129.444789][  T934] [<ffffffd816231900>] shrink_work+0x21c/0x248
[  129.445167][  T934] kernel BUG at kernel/sched/walt/walt_debug.c:16!
[  129.445183][  T934] Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
[  129.445204][  T934] Skip md ftrace buffer dump for: 0x1609e0
[  129.447348][  T934] CPU: 1 PID: 934 Comm: kworker/1:4 Tainted: G        W  OE      6.6.56-android15-8-o-g6f82312b30b9-debug #1 1400000003000000474e5500b3187743670464e8
[  129.447362][  T934] Hardware name: Qualcomm Technologies, Inc. Parrot QRD, Alpha-M (DT)
[  129.447373][  T934] Workqueue: dm_bufio_cache shrink_work
[  129.447394][  T934] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[  129.447406][  T934] pc : android_rvh_schedule_bug+0x0/0x8 [sched_walt_debug]
[  129.447435][  T934] lr : __traceiter_android_rvh_schedule_bug+0x44/0x6c
[  129.447451][  T934] sp : ffffffc0843dbc90
[  129.447459][  T934] x29: ffffffc0843dbc90 x28: ffffffffffffffff x27: 0000000000000c8b
[  129.447479][  T934] x26: 0000000000000040 x25: ffffff804b3d6260 x24: ffffffd816232b68
[  129.447497][  T934] x23: ffffff805171c5b4 x22: 0000000000000000 x21: ffffffd816231900
[  129.447517][  T934] x20: ffffff80306ba898 x19: 0000000000000000 x18: ffffffc084159030
[  129.447535][  T934] x17: 00000000d2b5dd1f x16: 00000000d2b5dd1f x15: ffffffd816720358
[  129.447554][  T934] x14: 0000000000000004 x13: ffffff89ef978000 x12: 0000000000000003
[  129.447572][  T934] x11: ffffffd817a823c4 x10: 0000000000000202 x9 : 7e779c5735de9400
[  129.447591][  T934] x8 : ffffffd81560d004 x7 : 205b5d3938373434 x6 : ffffffd8167397c8
[  129.447610][  T934] x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffffffc0843db9e0
[  129.447629][  T934] x2 : 0000000000002f15 x1 : 0000000000000000 x0 : 0000000000000000
[  129.447647][  T934] Call trace:
[  129.447655][  T934]  android_rvh_schedule_bug+0x0/0x8 [sched_walt_debug 1400000003000000474e550080cce8a8a78606b6]
[  129.447681][  T934]  __might_resched+0x190/0x1a8
[  129.447694][  T934]  shrink_work+0x180/0x248
[  129.447706][  T934]  process_one_work+0x260/0x624
[  129.447718][  T934]  worker_thread+0x28c/0x454
[  129.447729][  T934]  kthread+0x118/0x158
[  129.447742][  T934]  ret_from_fork+0x10/0x20
[  129.447761][  T934] Code: ???????? ???????? ???????? d2b5dd1f (d4210000)
[  129.447772][  T934] ---[ end trace 0000000000000000 ]---

dm_bufio_lock will call spin_lock_bh when try_verify_in_tasklet
is enabled, and __scan will be called in atomic context.

Fixes: 7cd3267 ("dm bufio: remove dm_bufio_cond_resched()")
Signed-off-by: LongPing Wei <weilongping@oppo.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
l1k pushed a commit that referenced this pull request May 6, 2025
Commit ddd0a42 only increments scomp_scratch_users when it was 0,
causing a panic when using ipcomp:

    Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI
    KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
    CPU: 1 UID: 0 PID: 619 Comm: ping Tainted: G                 N  6.15.0-rc3-net-00032-ga79be02bba5c torvalds#41 PREEMPT(full)
    Tainted: [N]=TEST
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014
    RIP: 0010:inflate_fast+0x5a2/0x1b90
    [...]
    Call Trace:
     <IRQ>
     zlib_inflate+0x2d60/0x6620
     deflate_sdecompress+0x166/0x350
     scomp_acomp_comp_decomp+0x45f/0xa10
     scomp_acomp_decompress+0x21/0x120
     acomp_do_req_chain+0x3e5/0x4e0
     ipcomp_input+0x212/0x550
     xfrm_input+0x2de2/0x72f0
    [...]
    Kernel panic - not syncing: Fatal exception in interrupt
    Kernel Offset: disabled
    ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---

Instead, let's keep the old increment, and decrement back to 0 if the
scratch allocation fails.

Fixes: ddd0a42 ("crypto: scompress - Fix scratch allocation failure handling")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
l1k pushed a commit that referenced this pull request May 6, 2025
For some SPI flash memory operations, dummy bytes are not mandatory. For
example, in Winbond SPINAND flash memory devices, the `write_cache` and
`update_cache` operation variants have zero dummy bytes. Calculating the
duration for SPI memory operations with zero dummy bytes causes
a divide error when `ncycles` is calculated in the
spi_mem_calc_op_duration().

Add changes to skip the 'ncylcles' calculation for zero dummy bytes.

Following divide error is fixed by this change:

 Oops: divide error: 0000 [#1] PREEMPT SMP NOPTI
...

  ? do_trap+0xdb/0x100
  ? do_error_trap+0x75/0xb0
  ? spi_mem_calc_op_duration+0x56/0xb0
  ? exc_divide_error+0x3b/0x70
  ? spi_mem_calc_op_duration+0x56/0xb0
  ? asm_exc_divide_error+0x1b/0x20
  ? spi_mem_calc_op_duration+0x56/0xb0
  ? spinand_select_op_variant+0xee/0x190 [spinand]
  spinand_match_and_init+0x13e/0x1a0 [spinand]
  spinand_manufacturer_match+0x6e/0xa0 [spinand]
  spinand_probe+0x357/0x7f0 [spinand]
  ? kernfs_activate+0x87/0xd0
  spi_mem_probe+0x7a/0xb0
  spi_probe+0x7d/0x130

Fixes: 226d6cb ("spi: spi-mem: Estimate the time taken by operations")
Suggested-by: Krishnamoorthi M <krishnamoorthi.m@amd.com>
Co-developed-by: Akshata MukundShetty <akshata.mukundshetty@amd.com>
Signed-off-by: Akshata MukundShetty <akshata.mukundshetty@amd.com>
Signed-off-by: Raju Rangoju <Raju.Rangoju@amd.com>
Link: https://patch.msgid.link/20250424121333.417372-1-Raju.Rangoju@amd.com
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
l1k pushed a commit that referenced this pull request May 6, 2025
queue->state_change is set as part of nvmet_tcp_set_queue_sock(), but if
the TCP connection isn't established when nvmet_tcp_set_queue_sock() is
called then queue->state_change isn't set and sock->sk->sk_state_change
isn't replaced.

As such we don't need to restore sock->sk->sk_state_change if
queue->state_change is NULL.

This avoids NULL pointer dereferences such as this:

[  286.462026][    C0] BUG: kernel NULL pointer dereference, address: 0000000000000000
[  286.462814][    C0] #PF: supervisor instruction fetch in kernel mode
[  286.463796][    C0] #PF: error_code(0x0010) - not-present page
[  286.464392][    C0] PGD 8000000140620067 P4D 8000000140620067 PUD 114201067 PMD 0
[  286.465086][    C0] Oops: Oops: 0010 [#1] SMP KASAN PTI
[  286.465559][    C0] CPU: 0 UID: 0 PID: 1628 Comm: nvme Not tainted 6.15.0-rc2+ torvalds#11 PREEMPT(voluntary)
[  286.466393][    C0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014
[  286.467147][    C0] RIP: 0010:0x0
[  286.467420][    C0] Code: Unable to access opcode bytes at 0xffffffffffffffd6.
[  286.467977][    C0] RSP: 0018:ffff8883ae008580 EFLAGS: 00010246
[  286.468425][    C0] RAX: 0000000000000000 RBX: ffff88813fd34100 RCX: ffffffffa386cc43
[  286.469019][    C0] RDX: 1ffff11027fa68b6 RSI: 0000000000000008 RDI: ffff88813fd34100
[  286.469545][    C0] RBP: ffff88813fd34160 R08: 0000000000000000 R09: ffffed1027fa682c
[  286.470072][    C0] R10: ffff88813fd34167 R11: 0000000000000000 R12: ffff88813fd344c3
[  286.470585][    C0] R13: ffff88813fd34112 R14: ffff88813fd34aec R15: ffff888132cdd268
[  286.471070][    C0] FS:  00007fe3c04c7d80(0000) GS:ffff88840743f000(0000) knlGS:0000000000000000
[  286.471644][    C0] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  286.472543][    C0] CR2: ffffffffffffffd6 CR3: 000000012daca000 CR4: 00000000000006f0
[  286.473500][    C0] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  286.474467][    C0] DR3: 0000000000000000 DR6: 00000000ffff07f0 DR7: 0000000000000400
[  286.475453][    C0] Call Trace:
[  286.476102][    C0]  <IRQ>
[  286.476719][    C0]  tcp_fin+0x2bb/0x440
[  286.477429][    C0]  tcp_data_queue+0x190f/0x4e60
[  286.478174][    C0]  ? __build_skb_around+0x234/0x330
[  286.478940][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.479659][    C0]  ? __pfx_tcp_data_queue+0x10/0x10
[  286.480431][    C0]  ? tcp_try_undo_loss+0x640/0x6c0
[  286.481196][    C0]  ? seqcount_lockdep_reader_access.constprop.0+0x82/0x90
[  286.482046][    C0]  ? kvm_clock_get_cycles+0x14/0x30
[  286.482769][    C0]  ? ktime_get+0x66/0x150
[  286.483433][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.484146][    C0]  tcp_rcv_established+0x6e4/0x2050
[  286.484857][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.485523][    C0]  ? ipv4_dst_check+0x160/0x2b0
[  286.486203][    C0]  ? __pfx_tcp_rcv_established+0x10/0x10
[  286.486917][    C0]  ? lock_release+0x217/0x2c0
[  286.487595][    C0]  tcp_v4_do_rcv+0x4d6/0x9b0
[  286.488279][    C0]  tcp_v4_rcv+0x2af8/0x3e30
[  286.488904][    C0]  ? raw_local_deliver+0x51b/0xad0
[  286.489551][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.490198][    C0]  ? __pfx_tcp_v4_rcv+0x10/0x10
[  286.490813][    C0]  ? __pfx_raw_local_deliver+0x10/0x10
[  286.491487][    C0]  ? __pfx_nf_confirm+0x10/0x10 [nf_conntrack]
[  286.492275][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.492900][    C0]  ip_protocol_deliver_rcu+0x8f/0x370
[  286.493579][    C0]  ip_local_deliver_finish+0x297/0x420
[  286.494268][    C0]  ip_local_deliver+0x168/0x430
[  286.494867][    C0]  ? __pfx_ip_local_deliver+0x10/0x10
[  286.495498][    C0]  ? __pfx_ip_local_deliver_finish+0x10/0x10
[  286.496204][    C0]  ? ip_rcv_finish_core+0x19a/0x1f20
[  286.496806][    C0]  ? lock_release+0x217/0x2c0
[  286.497414][    C0]  ip_rcv+0x455/0x6e0
[  286.497945][    C0]  ? __pfx_ip_rcv+0x10/0x10
[  286.498550][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.499137][    C0]  ? __pfx_ip_rcv_finish+0x10/0x10
[  286.499763][    C0]  ? lock_release+0x217/0x2c0
[  286.500327][    C0]  ? dl_scaled_delta_exec+0xd1/0x2c0
[  286.500922][    C0]  ? __pfx_ip_rcv+0x10/0x10
[  286.501480][    C0]  __netif_receive_skb_one_core+0x166/0x1b0
[  286.502173][    C0]  ? __pfx___netif_receive_skb_one_core+0x10/0x10
[  286.502903][    C0]  ? lock_acquire+0x2b2/0x310
[  286.503487][    C0]  ? process_backlog+0x372/0x1350
[  286.504087][    C0]  ? lock_release+0x217/0x2c0
[  286.504642][    C0]  process_backlog+0x3b9/0x1350
[  286.505214][    C0]  ? process_backlog+0x372/0x1350
[  286.505779][    C0]  __napi_poll.constprop.0+0xa6/0x490
[  286.506363][    C0]  net_rx_action+0x92e/0xe10
[  286.506889][    C0]  ? __pfx_net_rx_action+0x10/0x10
[  286.507437][    C0]  ? timerqueue_add+0x1f0/0x320
[  286.507977][    C0]  ? sched_clock_cpu+0x68/0x540
[  286.508492][    C0]  ? lock_acquire+0x2b2/0x310
[  286.509043][    C0]  ? kvm_sched_clock_read+0xd/0x20
[  286.509607][    C0]  ? handle_softirqs+0x1aa/0x7d0
[  286.510187][    C0]  handle_softirqs+0x1f2/0x7d0
[  286.510754][    C0]  ? __pfx_handle_softirqs+0x10/0x10
[  286.511348][    C0]  ? irqtime_account_irq+0x181/0x290
[  286.511937][    C0]  ? __dev_queue_xmit+0x85d/0x3450
[  286.512510][    C0]  do_softirq.part.0+0x89/0xc0
[  286.513100][    C0]  </IRQ>
[  286.513548][    C0]  <TASK>
[  286.513953][    C0]  __local_bh_enable_ip+0x112/0x140
[  286.514522][    C0]  ? __dev_queue_xmit+0x85d/0x3450
[  286.515072][    C0]  __dev_queue_xmit+0x872/0x3450
[  286.515619][    C0]  ? nft_do_chain+0xe16/0x15b0 [nf_tables]
[  286.516252][    C0]  ? __pfx___dev_queue_xmit+0x10/0x10
[  286.516817][    C0]  ? selinux_ip_postroute+0x43c/0xc50
[  286.517433][    C0]  ? __pfx_selinux_ip_postroute+0x10/0x10
[  286.518061][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.518606][    C0]  ? ip_output+0x164/0x4a0
[  286.519149][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.519671][    C0]  ? ip_finish_output2+0x17d5/0x1fb0
[  286.520258][    C0]  ip_finish_output2+0xb4b/0x1fb0
[  286.520787][    C0]  ? __pfx_ip_finish_output2+0x10/0x10
[  286.521355][    C0]  ? __ip_finish_output+0x15d/0x750
[  286.521890][    C0]  ip_output+0x164/0x4a0
[  286.522372][    C0]  ? __pfx_ip_output+0x10/0x10
[  286.522872][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.523402][    C0]  ? _raw_spin_unlock_irqrestore+0x4c/0x60
[  286.524031][    C0]  ? __pfx_ip_finish_output+0x10/0x10
[  286.524605][    C0]  ? __ip_queue_xmit+0x999/0x2260
[  286.525200][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.525744][    C0]  ? ipv4_dst_check+0x16a/0x2b0
[  286.526279][    C0]  ? lock_release+0x217/0x2c0
[  286.526793][    C0]  __ip_queue_xmit+0x1883/0x2260
[  286.527324][    C0]  ? __skb_clone+0x54c/0x730
[  286.527827][    C0]  __tcp_transmit_skb+0x209b/0x37a0
[  286.528374][    C0]  ? __pfx___tcp_transmit_skb+0x10/0x10
[  286.528952][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.529472][    C0]  ? seqcount_lockdep_reader_access.constprop.0+0x82/0x90
[  286.530152][    C0]  ? trace_hardirqs_on+0x12/0x120
[  286.530691][    C0]  tcp_write_xmit+0xb81/0x88b0
[  286.531224][    C0]  ? mod_memcg_state+0x4d/0x60
[  286.531736][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.532253][    C0]  __tcp_push_pending_frames+0x90/0x320
[  286.532826][    C0]  tcp_send_fin+0x141/0xb50
[  286.533352][    C0]  ? __pfx_tcp_send_fin+0x10/0x10
[  286.533908][    C0]  ? __local_bh_enable_ip+0xab/0x140
[  286.534495][    C0]  inet_shutdown+0x243/0x320
[  286.535077][    C0]  nvme_tcp_alloc_queue+0xb3b/0x2590 [nvme_tcp]
[  286.535709][    C0]  ? do_raw_spin_lock+0x129/0x260
[  286.536314][    C0]  ? __pfx_nvme_tcp_alloc_queue+0x10/0x10 [nvme_tcp]
[  286.536996][    C0]  ? do_raw_spin_unlock+0x54/0x1e0
[  286.537550][    C0]  ? _raw_spin_unlock+0x29/0x50
[  286.538127][    C0]  ? do_raw_spin_lock+0x129/0x260
[  286.538664][    C0]  ? __pfx_do_raw_spin_lock+0x10/0x10
[  286.539249][    C0]  ? nvme_tcp_alloc_admin_queue+0xd5/0x340 [nvme_tcp]
[  286.539892][    C0]  ? __wake_up+0x40/0x60
[  286.540392][    C0]  nvme_tcp_alloc_admin_queue+0xd5/0x340 [nvme_tcp]
[  286.541047][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.541589][    C0]  nvme_tcp_setup_ctrl+0x8b/0x7a0 [nvme_tcp]
[  286.542254][    C0]  ? _raw_spin_unlock_irqrestore+0x4c/0x60
[  286.542887][    C0]  ? __pfx_nvme_tcp_setup_ctrl+0x10/0x10 [nvme_tcp]
[  286.543568][    C0]  ? trace_hardirqs_on+0x12/0x120
[  286.544166][    C0]  ? _raw_spin_unlock_irqrestore+0x35/0x60
[  286.544792][    C0]  ? nvme_change_ctrl_state+0x196/0x2e0 [nvme_core]
[  286.545477][    C0]  nvme_tcp_create_ctrl+0x839/0xb90 [nvme_tcp]
[  286.546126][    C0]  nvmf_dev_write+0x3db/0x7e0 [nvme_fabrics]
[  286.546775][    C0]  ? rw_verify_area+0x69/0x520
[  286.547334][    C0]  vfs_write+0x218/0xe90
[  286.547854][    C0]  ? do_syscall_64+0x9f/0x190
[  286.548408][    C0]  ? trace_hardirqs_on_prepare+0xdb/0x120
[  286.549037][    C0]  ? syscall_exit_to_user_mode+0x93/0x280
[  286.549659][    C0]  ? __pfx_vfs_write+0x10/0x10
[  286.550259][    C0]  ? do_syscall_64+0x9f/0x190
[  286.550840][    C0]  ? syscall_exit_to_user_mode+0x8e/0x280
[  286.551516][    C0]  ? trace_hardirqs_on_prepare+0xdb/0x120
[  286.552180][    C0]  ? syscall_exit_to_user_mode+0x93/0x280
[  286.552834][    C0]  ? ksys_read+0xf5/0x1c0
[  286.553386][    C0]  ? __pfx_ksys_read+0x10/0x10
[  286.553964][    C0]  ksys_write+0xf5/0x1c0
[  286.554499][    C0]  ? __pfx_ksys_write+0x10/0x10
[  286.555072][    C0]  ? trace_hardirqs_on_prepare+0xdb/0x120
[  286.555698][    C0]  ? syscall_exit_to_user_mode+0x93/0x280
[  286.556319][    C0]  ? do_syscall_64+0x54/0x190
[  286.556866][    C0]  do_syscall_64+0x93/0x190
[  286.557420][    C0]  ? rcu_read_unlock+0x17/0x60
[  286.557986][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.558526][    C0]  ? lock_release+0x217/0x2c0
[  286.559087][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.559659][    C0]  ? count_memcg_events.constprop.0+0x4a/0x60
[  286.560476][    C0]  ? exc_page_fault+0x7a/0x110
[  286.561064][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.561647][    C0]  ? lock_release+0x217/0x2c0
[  286.562257][    C0]  ? do_user_addr_fault+0x171/0xa00
[  286.562839][    C0]  ? do_user_addr_fault+0x4a2/0xa00
[  286.563453][    C0]  ? irqentry_exit_to_user_mode+0x84/0x270
[  286.564112][    C0]  ? rcu_is_watching+0x11/0xb0
[  286.564677][    C0]  ? irqentry_exit_to_user_mode+0x84/0x270
[  286.565317][    C0]  ? trace_hardirqs_on_prepare+0xdb/0x120
[  286.565922][    C0]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  286.566542][    C0] RIP: 0033:0x7fe3c05e6504
[  286.567102][    C0] Code: c7 00 16 00 00 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d c5 8b 10 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 55 48 89 e5 48 83 ec 20 48 89
[  286.568931][    C0] RSP: 002b:00007fff76444f58 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
[  286.569807][    C0] RAX: ffffffffffffffda RBX: 000000003b40d930 RCX: 00007fe3c05e6504
[  286.570621][    C0] RDX: 00000000000000cf RSI: 000000003b40d930 RDI: 0000000000000003
[  286.571443][    C0] RBP: 0000000000000003 R08: 00000000000000cf R09: 000000003b40d930
[  286.572246][    C0] R10: 0000000000000000 R11: 0000000000000202 R12: 000000003b40cd60
[  286.573069][    C0] R13: 00000000000000cf R14: 00007fe3c07417f8 R15: 00007fe3c073502e
[  286.573886][    C0]  </TASK>

Closes: https://lore.kernel.org/linux-nvme/5hdonndzoqa265oq3bj6iarwtfk5dewxxjtbjvn5uqnwclpwt6@a2n6w3taxxex/
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
l1k pushed a commit that referenced this pull request May 6, 2025
Use a separate lock in the polling function eu_stall_data_buf_poll()
instead of eu_stall->stream_lock. This would prevent a possible
circular locking dependency leading to a deadlock as described below.
This would also require additional locking with the new lock in
the read function.

<4> [787.192986] ======================================================
<4> [787.192988] WARNING: possible circular locking dependency detected
<4> [787.192991] 6.14.0-rc7-xe+ #1 Tainted: G     U
<4> [787.192993] ------------------------------------------------------
<4> [787.192994] xe_eu_stall/20093 is trying to acquire lock:
<4> [787.192996] ffff88819847e2c0 ((work_completion)
(&(&stream->buf_poll_work)->work)), at: __flush_work+0x1f8/0x5e0
<4> [787.193005] but task is already holding lock:
<4> [787.193007] ffff88814ce83ba8 (&gt->eu_stall->stream_lock){3:3},
at: xe_eu_stall_stream_ioctl+0x41/0x6a0 [xe]
<4> [787.193090] which lock already depends on the new lock.
<4> [787.193093] the existing dependency chain (in reverse order) is:
<4> [787.193095]
-> #1 (&gt->eu_stall->stream_lock){+.+.}-{3:3}:
<4> [787.193099]        __mutex_lock+0xb4/0xe40
<4> [787.193104]        mutex_lock_nested+0x1b/0x30
<4> [787.193106]        eu_stall_data_buf_poll_work_fn+0x44/0x1d0 [xe]
<4> [787.193155]        process_one_work+0x21c/0x740
<4> [787.193159]        worker_thread+0x1db/0x3c0
<4> [787.193161]        kthread+0x10d/0x270
<4> [787.193164]        ret_from_fork+0x44/0x70
<4> [787.193168]        ret_from_fork_asm+0x1a/0x30
<4> [787.193172]
-> #0 ((work_completion)(&(&stream->buf_poll_work)->work)){+.+.}-{0:0}:
<4> [787.193176]        __lock_acquire+0x1637/0x2810
<4> [787.193180]        lock_acquire+0xc9/0x300
<4> [787.193183]        __flush_work+0x219/0x5e0
<4> [787.193186]        cancel_delayed_work_sync+0x87/0x90
<4> [787.193189]        xe_eu_stall_disable_locked+0x9a/0x260 [xe]
<4> [787.193237]        xe_eu_stall_stream_ioctl+0x5b/0x6a0 [xe]
<4> [787.193285]        __x64_sys_ioctl+0xa4/0xe0
<4> [787.193289]        x64_sys_call+0x131e/0x2650
<4> [787.193292]        do_syscall_64+0x91/0x180
<4> [787.193295]        entry_SYSCALL_64_after_hwframe+0x76/0x7e
<4> [787.193299]
other info that might help us debug this:
<4> [787.193302]  Possible unsafe locking scenario:
<4> [787.193304]        CPU0                    CPU1
<4> [787.193305]        ----                    ----
<4> [787.193306]   lock(&gt->eu_stall->stream_lock);
<4> [787.193308]                        lock((work_completion)
					(&(&stream->buf_poll_work)->work));
<4> [787.193311]                        lock(&gt->eu_stall->stream_lock);
<4> [787.193313]   lock((work_completion)
			(&(&stream->buf_poll_work)->work));
<4> [787.193315]
 *** DEADLOCK ***

Fixes: 760edec ("drm/xe/eustall: Add support to read() and poll() EU stall data")
Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/4598
Signed-off-by: Harish Chegondi <harish.chegondi@intel.com>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Link: https://lore.kernel.org/r/c896932fca84f79db2df5942911997ed77b2b9b6.1744934656.git.harish.chegondi@intel.com
(cherry picked from commit c2b1f1b)
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
l1k pushed a commit that referenced this pull request May 6, 2025
Commit a595138 ("arm64: errata: Add newer ARM cores to the
spectre_bhb_loop_affected() lists") added some additional CPUs to the
Spectre-BHB workaround, including some new arrays for designs that
require new 'k' values for the workaround to be effective.

Unfortunately, the new arrays omitted the sentinel entry and so
is_midr_in_range_list() will walk off the end when it doesn't find a
match. With UBSAN enabled, this leads to a crash during boot when
is_midr_in_range_list() is inlined (which was more common prior to
c8c2647 ("arm64: Make  _midr_in_range_list() an exported
function")):

 |  Internal error: aarch64 BRK: 00000000f2000001 [#1] PREEMPT SMP
 |  pstate: 804000c5 (Nzcv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 |  pc : spectre_bhb_loop_affected+0x28/0x30
 |  lr : is_spectre_bhb_affected+0x170/0x190
 | [...]
 |  Call trace:
 |   spectre_bhb_loop_affected+0x28/0x30
 |   update_cpu_capabilities+0xc0/0x184
 |   init_cpu_features+0x188/0x1a4
 |   cpuinfo_store_boot_cpu+0x4c/0x60
 |   smp_prepare_boot_cpu+0x38/0x54
 |   start_kernel+0x8c/0x478
 |   __primary_switched+0xc8/0xd4
 |  Code: 6b09011f 54000061 52801080 d65f03c0 (d4200020)
 |  ---[ end trace 0000000000000000 ]---
 |  Kernel panic - not syncing: aarch64 BRK: Fatal exception

Add the missing sentinel entries.

Cc: Lee Jones <lee@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Doug Anderson <dianders@chromium.org>
Cc: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Cc: <stable@vger.kernel.org>
Reported-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixes: a595138 ("arm64: errata: Add newer ARM cores to the spectre_bhb_loop_affected() lists")
Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Lee Jones <lee@kernel.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20250501104747.28431-1-will@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
l1k pushed a commit that referenced this pull request Jun 5, 2025
I started seeing this in recent Fedora 42 kernels:

  # uname -a
  Linux number 6.14.3-300.fc42.x86_64 #1 SMP PREEMPT_DYNAMIC Sun Apr 20 16:08:39 UTC 2025 x86_64 GNU/Linux
  #

  # perf test vmlinux
    1: vmlinux symtab matches kallsyms                                 : FAILED!
  #

Where we have Rust enabled:

  # grep CONFIG_RUST /boot/config-6.14.3-300.fc42.x86_64
  CONFIG_RUSTC_VERSION=108600
  CONFIG_RUST_IS_AVAILABLE=y
  CONFIG_RUSTC_LLVM_VERSION=200101
  CONFIG_RUSTC_HAS_COERCE_POINTEE=y
  CONFIG_RUST=y
  CONFIG_RUSTC_VERSION_TEXT="rustc 1.86.0 (05f9846f8 2025-03-31) (Fedora 1.86.0-1.fc42)"
  CONFIG_RUST_FW_LOADER_ABSTRACTIONS=y
  CONFIG_RUST_PHYLIB_ABSTRACTIONS=y
  # CONFIG_RUST_DEBUG_ASSERTIONS is not set
  CONFIG_RUST_OVERFLOW_CHECKS=y
  # CONFIG_RUST_BUILD_ASSERT_ALLOW is not set
  #

Looking at the reason for the failure:

  # perf test -v vmlinux |& grep ^ERR
  ERR : 0xffffffff99efc7d0: __pfx__RNCINvNtNtNtCsf5tcb0XGUW4_4core4iter8adapters3map12map_try_foldjNtCsagR6JbSOIa9_12drm_panic_qr7VersionuINtNtNtBa_3ops12control_flow11ControlFlowB10_ENcB10_0NCINvNvNtNtNtB8_6traits8iterator8Iterator4find5checkB10_NCNvMB12_B10_13from_segments0E0E0B12_ not on kallsyms
  ERR : 0xffffffff99efc7e0: _RNCINvNtNtNtCsf5tcb0XGUW4_4core4iter8adapters3map12map_try_foldjNtCsagR6JbSOIa9_12drm_panic_qr7VersionuINtNtNtBa_3ops12control_flow11ControlFlowB10_ENcB10_0NCINvNvNtNtNtB8_6traits8iterator8Iterator4find5checkB10_NCNvMB12_B10_13from_segments0E0E0B12_ not on kallsyms
  #

But:

  # grep -w u /proc/kallsyms
  ffffffff99efc7d0 u __pfx__RNCINvNtNtNtCsf5tcb0XGUW4_4core4iter8adapters3map12map_try_foldjNtCsagR6JbSOIa9_12drm_panic_qr7VersionuINtNtNtBa_3ops12control_flow11ControlFlowB10_ENcB10_0NCINvNvNtNtNtB8_6traits8iterator8Iterator4find5checkB10_NCNvMB12_B10_13from_segments0E0E0B12_
  ffffffff99efc7e0 u _RNCINvNtNtNtCsf5tcb0XGUW4_4core4iter8adapters3map12map_try_foldjNtCsagR6JbSOIa9_12drm_panic_qr7VersionuINtNtNtBa_3ops12control_flow11ControlFlowB10_ENcB10_0NCINvNvNtNtNtB8_6traits8iterator8Iterator4find5checkB10_NCNvMB12_B10_13from_segments0E0E0B12_
  #

The test checks that "vmlinux symtab matches kallsyms", so it finds those two
symbols in vmlinux:

  # pahole --running_kernel_vmlinux
  /usr/lib/debug/lib/modules/6.14.3-300.fc42.x86_64/vmlinux
  #

  # readelf -sW /usr/lib/debug/lib/modules/6.14.3-300.fc42.x86_64/vmlinux | grep -Ew '(__pfx__RNCINvNtNtNtCsf5tcb0XGUW4_4core4iter8adapters3map12map_try_foldjNtCsagR6JbSOIa9_12drm_panic_qr7VersionuINtNtNtBa_3ops12control_flow11ControlFlowB10_ENcB10_0NCINvNvNtNtNtB8_6traits8iterator8Iterator4find5checkB10_NCNvMB12_B10_13from_segments0E0E0B12_|_RNCINvNtNtNtCsf5tcb0XGUW4_4core4iter8adapters3map12map_try_foldjNtCsagR6JbSOIa9_12drm_panic_qr7VersionuINtNtNtBa_3ops12control_flow11ControlFlowB10_ENcB10_0NCINvNvNtNtNtB8_6traits8iterator8Iterator4find5checkB10_NCNvMB12_B10_13from_segments0E0E0B12_)'
 81844: ffffffff81efc7e0   524 FUNC    LOCAL  DEFAULT    1 _RNCINvNtNtNtCsf5tcb0XGUW4_4core4iter8adapters3map12map_try_foldjNtCsagR6JbSOIa9_12drm_panic_qr7VersionuINtNtNtBa_3ops12control_flow11ControlFlowB10_ENcB10_0NCINvNvNtNtNtB8_6traits8iterator8Iterator4find5checkB10_NCNvMB12_B10_13from_segments0E0E0B12_
144259: ffffffff81efc7d0    16 FUNC    LOCAL  DEFAULT    1 __pfx__RNCINvNtNtNtCsf5tcb0XGUW4_4core4iter8adapters3map12map_try_foldjNtCsagR6JbSOIa9_12drm_panic_qr7VersionuINtNtNtBa_3ops12control_flow11ControlFlowB10_ENcB10_0NCINvNvNtNtNtB8_6traits8iterator8Iterator4find5checkB10_NCNvMB12_B10_13from_segments0E0E0B12_
  #

It is there.

From the nm documentation we can see that:

           "U" The symbol is undefined.

           "u" The symbol is a unique global symbol.  This is a GNU extension to the
	       standard set of ELF symbol bindings.  For such a symbol the dynamic
	       linker will make sure that in the entire process there is just one
	       symbol with this name and type in use.

So lets consider 'u' symbols in /proc/kallsyms when loading it to cover this case.

Fedora:40 shows this as a 'l' symbol, so consider that as well.

With this patch 'perf test 1' is happy again:

  # perf test vmlinux
    1: vmlinux symtab matches kallsyms                                 : Ok
  #

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/aBE_n0PGl3g6h-cS@x1
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
l1k pushed a commit that referenced this pull request Jun 5, 2025
Running the "perf script task-analyzer tests" with address sanitizer
showed a double free:
```
FAIL: "test_csv_extended_times" Error message: "Failed to find required string:'Out-Out;'."
=================================================================
==19190==ERROR: AddressSanitizer: attempting double-free on 0x50b000017b10 in thread T0:
    #0 0x55da9601c78a in free (perf+0x26078a) (BuildId: e7ef50e08970f017a96fde6101c5e2491acc674a)
    #1 0x55da96640c63 in filename__read_build_id tools/perf/util/symbol-minimal.c:221:2

0x50b000017b10 is located 0 bytes inside of 112-byte region [0x50b000017b10,0x50b000017b80)
freed by thread T0 here:
    #0 0x55da9601ce40 in realloc (perf+0x260e40) (BuildId: e7ef50e08970f017a96fde6101c5e2491acc674a)
    #1 0x55da96640ad6 in filename__read_build_id tools/perf/util/symbol-minimal.c:204:10

previously allocated by thread T0 here:
    #0 0x55da9601ca23 in malloc (perf+0x260a23) (BuildId: e7ef50e08970f017a96fde6101c5e2491acc674a)
    #1 0x55da966407e7 in filename__read_build_id tools/perf/util/symbol-minimal.c:181:9

SUMMARY: AddressSanitizer: double-free (perf+0x26078a) (BuildId: e7ef50e08970f017a96fde6101c5e2491acc674a) in free
==19190==ABORTING
FAIL: "invocation of perf script report task-analyzer --csv-summary csvsummary --summary-extended command failed" Error message: ""
FAIL: "test_csvsummary_extended" Error message: "Failed to find required string:'Out-Out;'."
---- end(-1) ----
132: perf script task-analyzer tests                                 : FAILED!
```

The buf_size if always set to phdr->p_filesz, but that may be 0
causing a free and realloc to return NULL. This is treated in
filename__read_build_id like a failure and the buffer is freed again.

To avoid this problem only grow buf, meaning the buf_size will never
be 0. This also reduces the number of memory (re)allocations.

Fixes: b691f64 ("perf symbols: Implement poor man's ELF parser")
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250501070003.22251-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
l1k pushed a commit that referenced this pull request Jun 5, 2025
Specify the threshold for dumping offcpu samples with --off-cpu-thresh,
the unit is milliseconds. Default value is 500ms.

Example:

  perf record --off-cpu --off-cpu-thresh 824

The example above collects direct off-cpu samples where the off-cpu time
is longer than 824ms.

Committer testing:

After commenting out the end off-cpu dump to have just the ones that are
added right after the task is scheduled back, and using a threshould of
1000ms, we see some periods (the 5th column, just before "offcpu-time"
in the 'perf script' output) that are over 1000.000.000 nanoseconds:

  root@number:~# perf record --off-cpu --off-cpu-thresh 10000
  ^C[ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 3.902 MB perf.data (34335 samples) ]
  root@number:~# perf script
<SNIP>
  Isolated Web Co   59932 [028] 63839.594437: 1000049427 offcpu-time:
             7fe63c7976c2 __syscall_cancel_arch_end+0x0 (/usr/lib64/libc.so.6)
             7fe63c78c04c __futex_abstimed_wait_common+0x7c (/usr/lib64/libc.so.6)
             7fe63c78e928 pthread_cond_timedwait@@GLIBC_2.3.2+0x178 (/usr/lib64/libc.so.6)
             5599974a9fe7 mozilla::detail::ConditionVariableImpl::wait_for(mozilla::detail::MutexImpl&, mozilla::BaseTimeDuration<mozilla::TimeDurationValueCalculator> const&)+0xe7 (/usr/lib64/fir>
                100000000 [unknown] ([unknown])

          swapper       0 [025] 63839.594459:     195724    cycles:P:  ffffffffac328270 read_tsc+0x0 ([kernel.kallsyms])
  Isolated Web Co   59932 [010] 63839.594466: 1000055278 offcpu-time:
             7fe63c7976c2 __syscall_cancel_arch_end+0x0 (/usr/lib64/libc.so.6)
             7fe63c78ba24 __syscall_cancel+0x14 (/usr/lib64/libc.so.6)
             7fe63c804c4e __poll+0x1e (/usr/lib64/libc.so.6)
             7fe633b0d1b8 PollWrapper(_GPollFD*, unsigned int, int) [clone .lto_priv.0]+0xf8 (/usr/lib64/firefox/libxul.so)
                10000002c [unknown] ([unknown])

          swapper       0 [027] 63839.594475:     134433    cycles:P:  ffffffffad4c45d9 irqentry_enter+0x19 ([kernel.kallsyms])
          swapper       0 [028] 63839.594499:     215838    cycles:P:  ffffffffac39199a switch_mm_irqs_off+0x10a ([kernel.kallsyms])
  MediaPD~oder #1 1407676 [027] 63839.594514:     134433    cycles:P:      7f982ef5e69f dct_IV(int*, int, int*)+0x24f (/usr/lib64/libfdk-aac.so.2.0.0)
          swapper       0 [024] 63839.594524:     267411    cycles:P:  ffffffffad4c6ee6 poll_idle+0x56 ([kernel.kallsyms])
  MediaSu~sor torvalds#75 1093827 [026] 63839.594555:     332652    cycles:P:      55be753ad030 moz_xmalloc+0x200 (/usr/lib64/firefox/firefox)
          swapper       0 [027] 63839.594616:     160548    cycles:P:  ffffffffad144840 menu_select+0x570 ([kernel.kallsyms])
  Isolated Web Co   14019 [027] 63839.595120: 1000050178 offcpu-time:
             7fc9537cc6c2 __syscall_cancel_arch_end+0x0 (/usr/lib64/libc.so.6)
             7fc9537c104c __futex_abstimed_wait_common+0x7c (/usr/lib64/libc.so.6)
             7fc9537c3928 pthread_cond_timedwait@@GLIBC_2.3.2+0x178 (/usr/lib64/libc.so.6)
             7fc95372a3c8 pt_TimedWait+0xb8 (/usr/lib64/libnspr4.so)
             7fc95372a8d8 PR_WaitCondVar+0x68 (/usr/lib64/libnspr4.so)
             7fc94afb1f7c WatchdogMain(void*)+0xac (/usr/lib64/firefox/libxul.so)
             7fc947498660 [unknown] ([unknown])
             7fc9535fce88 [unknown] ([unknown])
             7fc94b620e60 WatchdogManager::~WatchdogManager()+0x0 (/usr/lib64/firefox/libxul.so)
          fff8548387f8b48 [unknown] ([unknown])

          swapper       0 [003] 63839.595712:     212948    cycles:P:  ffffffffacd5b865 acpi_os_read_port+0x55 ([kernel.kallsyms])
<SNIP>

Suggested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Suggested-by: Ian Rogers <irogers@google.com>
Suggested-by: Namhyung Kim <namhyung@kernel.org>
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Howard Chu <howardchu95@gmail.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Gautam Menghani <gautam@linux.ibm.com>
Tested-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20241108204137.2444151-2-howardchu95@gmail.com
Link: https://lore.kernel.org/r/20250501022809.449767-10-howardchu95@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
l1k pushed a commit that referenced this pull request Jun 5, 2025
Despite the fact that several lockdep-related checks are skipped when
calling trylock* versions of the locking primitives, for example
mutex_trylock, each time the mutex is acquired, a held_lock is still
placed onto the lockdep stack by __lock_acquire() which is called
regardless of whether the trylock* or regular locking API was used.

This means that if the caller successfully acquires more than
MAX_LOCK_DEPTH locks of the same class, even when using mutex_trylock,
lockdep will still complain that the maximum depth of the held lock stack
has been reached and disable itself.

For example, the following error currently occurs in the ARM version
of KVM, once the code tries to lock all vCPUs of a VM configured with more
than MAX_LOCK_DEPTH vCPUs, a situation that can easily happen on modern
systems, where having more than 48 CPUs is common, and it's also common to
run VMs that have vCPU counts approaching that number:

[  328.171264] BUG: MAX_LOCK_DEPTH too low!
[  328.175227] turning off the locking correctness validator.
[  328.180726] Please attach the output of /proc/lock_stat to the bug report
[  328.187531] depth: 48  max: 48!
[  328.190678] 48 locks held by qemu-kvm/11664:
[  328.194957]  #0: ffff800086de5ba0 (&kvm->lock){+.+.}-{3:3}, at: kvm_ioctl_create_device+0x174/0x5b0
[  328.204048]  #1: ffff0800e78800b8 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0
[  328.212521]  #2: ffff07ffeee51e98 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0
[  328.220991]  #3: ffff0800dc7d80b8 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0
[  328.229463]  #4: ffff07ffe0c980b8 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0
[  328.237934]  #5: ffff0800a3883c78 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0
[  328.246405]  #6: ffff07fffbe480b8 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0

Luckily, in all instances that require locking all vCPUs, the
'kvm->lock' is taken a priori, and that fact makes it possible to use
the little known feature of lockdep, called a 'nest_lock', to avoid this
warning and subsequent lockdep self-disablement.

The action of 'nested lock' being provided to lockdep's lock_acquire(),
causes the lockdep to detect that the top of the held lock stack contains
a lock of the same class and then increment its reference counter instead
of pushing a new held_lock item onto that stack.

See __lock_acquire for more information.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Message-ID: <20250512180407.659015-2-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
l1k pushed a commit that referenced this pull request Jun 5, 2025
Use kvm_trylock_all_vcpus instead of a custom implementation when locking
all vCPUs of a VM, to avoid triggering a lockdep warning, in the case in
which the VM is configured to have more than MAX_LOCK_DEPTH vCPUs.

This fixes the following false lockdep warning:

[  328.171264] BUG: MAX_LOCK_DEPTH too low!
[  328.175227] turning off the locking correctness validator.
[  328.180726] Please attach the output of /proc/lock_stat to the bug report
[  328.187531] depth: 48  max: 48!
[  328.190678] 48 locks held by qemu-kvm/11664:
[  328.194957]  #0: ffff800086de5ba0 (&kvm->lock){+.+.}-{3:3}, at: kvm_ioctl_create_device+0x174/0x5b0
[  328.204048]  #1: ffff0800e78800b8 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0
[  328.212521]  #2: ffff07ffeee51e98 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0
[  328.220991]  #3: ffff0800dc7d80b8 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0
[  328.229463]  #4: ffff07ffe0c980b8 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0
[  328.237934]  #5: ffff0800a3883c78 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0
[  328.246405]  #6: ffff07fffbe480b8 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Message-ID: <20250512180407.659015-6-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
l1k pushed a commit that referenced this pull request Jun 5, 2025
The same buf is used for the program headers and reading notes. As the
notes memory may be reallocated then this corrupts the memory pointed
to by the phdr. Using the same buffer is in any case a logic
error. Rather than deal with the duplicated code, introduce an elf32
boolean and a union for either the elf32 or elf64 headers that are in
use. Let the program headers have their own memory and grow the buffer
for notes as necessary.

Before `perf list -j` compiled with asan would crash with:
```
==4176189==ERROR: AddressSanitizer: heap-use-after-free on address 0x5160000070b8 at pc 0x555d3b15075b bp 0x7ffebb5a8090 sp 0x7ffebb5a8088
READ of size 8 at 0x5160000070b8 thread T0
    #0 0x555d3b15075a in filename__read_build_id tools/perf/util/symbol-minimal.c:212:25
    #1 0x555d3ae43aff in filename__sprintf_build_id tools/perf/util/build-id.c:110:8
...

0x5160000070b8 is located 312 bytes inside of 560-byte region [0x516000006f80,0x5160000071b0)
freed by thread T0 here:
    #0 0x555d3ab21840 in realloc (perf+0x264840) (BuildId: 12dff2f6629f738e5012abdf0e90055518e70b5e)
    #1 0x555d3b1506e7 in filename__read_build_id tools/perf/util/symbol-minimal.c:206:11
...

previously allocated by thread T0 here:
    #0 0x555d3ab21423 in malloc (perf+0x264423) (BuildId: 12dff2f6629f738e5012abdf0e90055518e70b5e)
    #1 0x555d3b1503a2 in filename__read_build_id tools/perf/util/symbol-minimal.c:182:9
...
```

Note: this bug is long standing and not introduced by the other asan
fix in commit fa9c497 ("perf symbol-minimal: Fix double free in
filename__read_build_id").

Fixes: b691f64 ("perf symbols: Implement poor man's ELF parser")
Signed-off-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250528032637.198960-2-irogers@google.com
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Gary Guo <gary@garyguo.net>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Weilin Wang <weilin.wang@intel.com>
Cc: Andreas Hindborg <a.hindborg@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Stephen Brennan <stephen.s.brennan@oracle.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: Björn Roy Baron <bjorn3_gh@protonmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Trevor Gross <tmgross@umich.edu>
Cc: linux-kernel@vger.kernel.org
Cc: linux-perf-users@vger.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
l1k pushed a commit that referenced this pull request Jun 5, 2025
Add a compile-time check that `*$ptr` is of the type of `$type->$($f)*`.
Rename those placeholders for clarity.

Given the incorrect usage:

> diff --git a/rust/kernel/rbtree.rs b/rust/kernel/rbtree.rs
> index 8d978c8..6a7089149878 100644
> --- a/rust/kernel/rbtree.rs
> +++ b/rust/kernel/rbtree.rs
> @@ -329,7 +329,7 @@ fn raw_entry(&mut self, key: &K) -> RawEntry<'_, K, V> {
>          while !(*child_field_of_parent).is_null() {
>              let curr = *child_field_of_parent;
>              // SAFETY: All links fields we create are in a `Node<K, V>`.
> -            let node = unsafe { container_of!(curr, Node<K, V>, links) };
> +            let node = unsafe { container_of!(curr, Node<K, V>, key) };
>
>              // SAFETY: `node` is a non-null node so it is valid by the type invariants.
>              match key.cmp(unsafe { &(*node).key }) {

this patch produces the compilation error:

> error[E0308]: mismatched types
>    --> rust/kernel/lib.rs:220:45
>     |
> 220 |         $crate::assert_same_type(field_ptr, (&raw const (*container_ptr).$($fields)*).cast_mut());
>     |         ------------------------ ---------  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `*mut rb_node`, found `*mut K`
>     |         |                        |
>     |         |                        expected all arguments to be this `*mut bindings::rb_node` type because they need to match the type of this parameter
>     |         arguments to this function are incorrect
>     |
>    ::: rust/kernel/rbtree.rs:270:6
>     |
> 270 | impl<K, V> RBTree<K, V>
>     |      - found this type parameter
> ...
> 332 |             let node = unsafe { container_of!(curr, Node<K, V>, key) };
>     |                                 ------------------------------------ in this macro invocation
>     |
>     = note: expected raw pointer `*mut bindings::rb_node`
>                found raw pointer `*mut K`
> note: function defined here
>    --> rust/kernel/lib.rs:227:8
>     |
> 227 | pub fn assert_same_type<T>(_: T, _: T) {}
>     |        ^^^^^^^^^^^^^^^^ -  ----  ---- this parameter needs to match the `*mut bindings::rb_node` type of parameter #1
>     |                         |  |
>     |                         |  parameter #2 needs to match the `*mut bindings::rb_node` type of this parameter
>     |                         parameter #1 and parameter #2 both reference this parameter `T`
>     = note: this error originates in the macro `container_of` (in Nightly builds, run with -Z macro-backtrace for more info)

[ We decided to go with a variation of v1 [1] that became v4, since it
  seems like the obvious approach, the error messages seem good enough
  and the debug performance should be fine, given the kernel is always
  built with -O2.

  In the future, we may want to make the helper non-hidden, with
  proper documentation, for others to use.

  [1] https://lore.kernel.org/rust-for-linux/CANiq72kQWNfSV0KK6qs6oJt+aGdgY=hXg=wJcmK3zYcokY1LNw@mail.gmail.com/

    - Miguel ]

Suggested-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/all/CAH5fLgh6gmqGBhPMi2SKn7mCmMWfOSiS0WP5wBuGPYh9ZTAiww@mail.gmail.com/
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Link: https://lore.kernel.org/r/20250529-b4-container-of-type-check-v4-1-bf3a7ad73cec@gmail.com
[ Added intra-doc link. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
l1k pushed a commit that referenced this pull request Jun 5, 2025
syzkaller has found another ugly race in the VGIC, this time dealing
with VGIC creation. Since kvm_vgic_create() doesn't sufficiently protect
against in-flight vCPU creations, it is possible to get a vCPU into the
kernel w/ an in-kernel VGIC but no allocation of private IRQs:

  Unable to handle kernel NULL pointer dereference at virtual address 0000000000000d20
  Mem abort info:
    ESR = 0x0000000096000046
    EC = 0x25: DABT (current EL), IL = 32 bits
    SET = 0, FnV = 0
    EA = 0, S1PTW = 0
    FSC = 0x06: level 2 translation fault
  Data abort info:
    ISV = 0, ISS = 0x00000046, ISS2 = 0x00000000
    CM = 0, WnR = 1, TnD = 0, TagAccess = 0
    GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
  user pgtable: 4k pages, 48-bit VAs, pgdp=0000000103e4f000
  [0000000000000d20] pgd=0800000102e1c403, p4d=0800000102e1c403, pud=0800000101146403, pmd=0000000000000000
  Internal error: Oops: 0000000096000046 [#1] PREEMPT SMP
  CPU: 9 UID: 0 PID: 246 Comm: test Not tainted 6.14.0-rc6-00097-g0c90821f5db8 torvalds#16
  Hardware name: linux,dummy-virt (DT)
  pstate: 814020c5 (Nzcv daIF +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
  pc : _raw_spin_lock_irqsave+0x34/0x8c
  lr : kvm_vgic_set_owner+0x54/0xa4
  sp : ffff80008086ba20
  x29: ffff80008086ba20 x28: ffff0000c19b5640 x27: 0000000000000000
  x26: 0000000000000000 x25: ffff0000c4879bd0 x24: 000000000000001e
  x23: 0000000000000000 x22: 0000000000000000 x21: ffff0000c487af80
  x20: ffff0000c487af18 x19: 0000000000000000 x18: 0000001afadd5a8b
  x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000001
  x14: ffff0000c19b56c0 x13: 0030c9adf9d9889e x12: ffffc263710e1908
  x11: 0000001afb0d74f2 x10: e0966b840b373664 x9 : ec806bf7d6a57cd5
  x8 : ffff80008086b980 x7 : 0000000000000001 x6 : 0000000000000001
  x5 : 0000000080800054 x4 : 4ec4ec4ec4ec4ec5 x3 : 0000000000000000
  x2 : 0000000000000001 x1 : 0000000000000000 x0 : 0000000000000d20
  Call trace:
   _raw_spin_lock_irqsave+0x34/0x8c (P)
   kvm_vgic_set_owner+0x54/0xa4
   kvm_timer_enable+0xf4/0x274
   kvm_arch_vcpu_run_pid_change+0xe0/0x380
   kvm_vcpu_ioctl+0x93c/0x9e0
   __arm64_sys_ioctl+0xb4/0xec
   invoke_syscall+0x48/0x110
   el0_svc_common.constprop.0+0x40/0xe0
   do_el0_svc+0x1c/0x28
   el0_svc+0x30/0xd0
   el0t_64_sync_handler+0x10c/0x138
   el0t_64_sync+0x198/0x19c
   Code: b9000841 d503201f 52800001 52800022 (88e17c02)
   ---[ end trace 0000000000000000 ]---

Plug the race by explicitly checking for an in-progress vCPU creation
and failing kvm_vgic_create() when that's the case. Add some comments to
document all the things kvm_vgic_create() is trying to guard against
too.

Reported-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Tested-by: Alexander Potapenko <glider@google.com>
Link: https://lore.kernel.org/r/20250523194722.4066715-6-oliver.upton@linux.dev
Signed-off-by: Marc Zyngier <maz@kernel.org>
l1k pushed a commit that referenced this pull request Jun 5, 2025
…ux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.16, take #1

- Make the irqbypass hooks resilient to changes in the GSI<->MSI
  routing, avoiding behind stale vLPI mappings being left behind. The
  fix is to resolve the VGIC IRQ using the host IRQ (which is stable)
  and nuking the vLPI mapping upon a routing change.

- Close another VGIC race where vCPU creation races with VGIC
  creation, leading to in-flight vCPUs entering the kernel w/o private
  IRQs allocated.

- Fix a build issue triggered by the recently added workaround for
  Ampere's AC04_CPU_23 erratum.

- Correctly sign-extend the VA when emulating a TLBI instruction
  potentially targeting a VNCR mapping.

- Avoid dereferencing a NULL pointer in the VGIC debug code, which can
  happen if the device doesn't have any mapping yet.
l1k pushed a commit that referenced this pull request Jun 5, 2025
The following issue happens with a buggy module:

BUG: unable to handle page fault for address: ffffffffc05d0218
PGD 1bd66f067 P4D 1bd66f067 PUD 1bd671067 PMD 101808067 PTE 0
Oops: Oops: 0000 [#1] SMP KASAN PTI
Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
RIP: 0010:sized_strscpy+0x81/0x2f0
RSP: 0018:ffff88812d76fa08 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffffffc0601010 RCX: dffffc0000000000
RDX: 0000000000000038 RSI: dffffc0000000000 RDI: ffff88812608da2d
RBP: 8080808080808080 R08: ffff88812608da2d R09: ffff88812608da68
R10: ffff88812608d82d R11: ffff88812608d810 R12: 0000000000000038
R13: ffff88812608da2d R14: ffffffffc05d0218 R15: fefefefefefefeff
FS:  00007fef552de740(0000) GS:ffff8884251c7000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffc05d0218 CR3: 00000001146f0000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ftrace_mod_get_kallsym+0x1ac/0x590
 update_iter_mod+0x239/0x5b0
 s_next+0x5b/0xa0
 seq_read_iter+0x8c9/0x1070
 seq_read+0x249/0x3b0
 proc_reg_read+0x1b0/0x280
 vfs_read+0x17f/0x920
 ksys_read+0xf3/0x1c0
 do_syscall_64+0x5f/0x2e0
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

The above issue may happen as follows:
(1) Add kprobe tracepoint;
(2) insmod test.ko;
(3)  Module triggers ftrace disabled;
(4) rmmod test.ko;
(5) cat /proc/kallsyms; --> Will trigger UAF as test.ko already removed;
ftrace_mod_get_kallsym()
...
strscpy(module_name, mod_map->mod->name, MODULE_NAME_LEN);
...

The problem is when a module triggers an issue with ftrace and
sets ftrace_disable. The ftrace_disable is set when an anomaly is
discovered and to prevent any more damage, ftrace stops all text
modification. The issue that happened was that the ftrace_disable stops
more than just the text modification.

When a module is loaded, its init functions can also be traced. Because
kallsyms deletes the init functions after a module has loaded, ftrace
saves them when the module is loaded and function tracing is enabled. This
allows the output of the function trace to show the init function names
instead of just their raw memory addresses.

When a module is removed, ftrace_release_mod() is called, and if
ftrace_disable is set, it just returns without doing anything more. The
problem here is that it leaves the mod_list still around and if kallsyms
is called, it will call into this code and access the module memory that
has already been freed as it will return:

  strscpy(module_name, mod_map->mod->name, MODULE_NAME_LEN);

Where the "mod" no longer exists and triggers a UAF bug.

Link: https://lore.kernel.org/all/20250523135452.626d8dcd@gandalf.local.home/

Cc: stable@vger.kernel.org
Fixes: aba4b5c ("ftrace: Save module init functions kallsyms symbols for tracing")
Link: https://lore.kernel.org/20250529111955.2349189-2-yebin@huaweicloud.com
Signed-off-by: Ye Bin <yebin10@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
l1k pushed a commit that referenced this pull request Jun 9, 2025
Don't set WDM_READ flag in wdm_in_callback() for ZLP-s, otherwise when
userspace tries to poll for available data, it might - incorrectly -
believe there is something available, and when it tries to non-blocking
read it, it might get stuck in the read loop.

For example this is what glib does for non-blocking read (briefly):

  1. poll()
  2. if poll returns with non-zero, starts a read data loop:
    a. loop on poll() (EINTR disabled)
    b. if revents was set, reads data
      I. if read returns with EINTR or EAGAIN, goto 2.a.
      II. otherwise return with data

So if ZLP sets WDM_READ (#1), we expect data, and try to read it (#2).
But as that was a ZLP, and we are doing non-blocking read, wdm_read()
returns with EAGAIN (#2.b.I), so loop again, and try to read again
(#2.a.).

With glib, we might stuck in this loop forever, as EINTR is disabled
(#2.a).

Signed-off-by: Robert Hodaszi <robert.hodaszi@digi.com>
Acked-by: Oliver Neukum <oneukum@suse.com>
Link: https://lore.kernel.org/r/20250403144004.3889125-1-robert.hodaszi@digi.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
l1k pushed a commit that referenced this pull request Jun 9, 2025
Reorder the initialization sequence in `usbhs_probe()` to enable runtime
PM before accessing registers, preventing potential crashes due to
uninitialized clocks.

Currently, in the probe path, registers are accessed before enabling the
clocks, leading to a synchronous external abort on the RZ/V2H SoC.
The problematic call flow is as follows:

    usbhs_probe()
        usbhs_sys_clock_ctrl()
            usbhs_bset()
                usbhs_write()
                    iowrite16()  <-- Register access before enabling clocks

Since `iowrite16()` is performed without ensuring the required clocks are
enabled, this can lead to access errors. To fix this, enable PM runtime
early in the probe function and ensure clocks are acquired before register
access, preventing crashes like the following on RZ/V2H:

[13.272640] Internal error: synchronous external abort: 0000000096000010 [#1] PREEMPT SMP
[13.280814] Modules linked in: cec renesas_usbhs(+) drm_kms_helper fuse drm backlight ipv6
[13.289088] CPU: 1 UID: 0 PID: 195 Comm: (udev-worker) Not tainted 6.14.0-rc7+ torvalds#98
[13.296640] Hardware name: Renesas RZ/V2H EVK Board based on r9a09g057h44 (DT)
[13.303834] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[13.310770] pc : usbhs_bset+0x14/0x4c [renesas_usbhs]
[13.315831] lr : usbhs_probe+0x2e4/0x5ac [renesas_usbhs]
[13.321138] sp : ffff8000827e3850
[13.324438] x29: ffff8000827e3860 x28: 0000000000000000 x27: ffff8000827e3ca0
[13.331554] x26: ffff8000827e3ba0 x25: ffff800081729668 x24: 0000000000000025
[13.338670] x23: ffff0000c0f08000 x22: 0000000000000000 x21: ffff0000c0f08010
[13.345783] x20: 0000000000000000 x19: ffff0000c3b52080 x18: 00000000ffffffff
[13.352895] x17: 0000000000000000 x16: 0000000000000000 x15: ffff8000827e36ce
[13.360009] x14: 00000000000003d7 x13: 00000000000003d7 x12: 0000000000000000
[13.367122] x11: 0000000000000000 x10: 0000000000000aa0 x9 : ffff8000827e3750
[13.374235] x8 : ffff0000c1850b00 x7 : 0000000003826060 x6 : 000000000000001c
[13.381347] x5 : 000000030d5fcc00 x4 : ffff8000825c0000 x3 : 0000000000000000
[13.388459] x2 : 0000000000000400 x1 : 0000000000000000 x0 : ffff0000c3b52080
[13.395574] Call trace:
[13.398013]  usbhs_bset+0x14/0x4c [renesas_usbhs] (P)
[13.403076]  platform_probe+0x68/0xdc
[13.406738]  really_probe+0xbc/0x2c0
[13.410306]  __driver_probe_device+0x78/0x120
[13.414653]  driver_probe_device+0x3c/0x154
[13.418825]  __driver_attach+0x90/0x1a0
[13.422647]  bus_for_each_dev+0x7c/0xe0
[13.426470]  driver_attach+0x24/0x30
[13.430032]  bus_add_driver+0xe4/0x208
[13.433766]  driver_register+0x68/0x130
[13.437587]  __platform_driver_register+0x24/0x30
[13.442273]  renesas_usbhs_driver_init+0x20/0x1000 [renesas_usbhs]
[13.448450]  do_one_initcall+0x60/0x1d4
[13.452276]  do_init_module+0x54/0x1f8
[13.456014]  load_module+0x1754/0x1c98
[13.459750]  init_module_from_file+0x88/0xcc
[13.464004]  __arm64_sys_finit_module+0x1c4/0x328
[13.468689]  invoke_syscall+0x48/0x104
[13.472426]  el0_svc_common.constprop.0+0xc0/0xe0
[13.477113]  do_el0_svc+0x1c/0x28
[13.480415]  el0_svc+0x30/0xcc
[13.483460]  el0t_64_sync_handler+0x10c/0x138
[13.487800]  el0t_64_sync+0x198/0x19c
[13.491453] Code: 2a0103e1 12003c42 12003c63 8b010084 (79400084)
[13.497522] ---[ end trace 0000000000000000 ]---

Fixes: f1407d5 ("usb: renesas_usbhs: Add Renesas USBHS common code")
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Tested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Link: https://lore.kernel.org/r/20250407105002.107181-4-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
l1k pushed a commit that referenced this pull request Jun 9, 2025
When threads/tasks are switched we need to ensure the old execution's
SR_SUM state is saved and the new thread has the old SR_SUM state
restored.

The issue was seen under heavy load especially with the syz-stress tool
running, with crashes as follows in schedule_tail:

Unable to handle kernel access to user memory without uaccess routines
at virtual address 000000002749f0d0
Oops [#1]
Modules linked in:
CPU: 1 PID: 4875 Comm: syz-executor.0 Not tainted
5.12.0-rc2-syzkaller-00467-g0d7588ab9ef9 #0
Hardware name: riscv-virtio,qemu (DT)
epc : schedule_tail+0x72/0xb2 kernel/sched/core.c:4264
 ra : task_pid_vnr include/linux/sched.h:1421 [inline]
 ra : schedule_tail+0x70/0xb2 kernel/sched/core.c:4264
epc : ffffffe00008c8b0 ra : ffffffe00008c8ae sp : ffffffe025d17ec0
 gp : ffffffe005d25378 tp : ffffffe00f0d0000 t0 : 0000000000000000
 t1 : 0000000000000001 t2 : 00000000000f4240 s0 : ffffffe025d17ee0
 s1 : 000000002749f0d0 a0 : 000000000000002a a1 : 0000000000000003
 a2 : 1ffffffc0cfac500 a3 : ffffffe0000c80cc a4 : 5ae9db91c19bbe00
 a5 : 0000000000000000 a6 : 0000000000f00000 a7 : ffffffe000082eba
 s2 : 0000000000040000 s3 : ffffffe00eef96c0 s4 : ffffffe022c77fe0
 s5 : 0000000000004000 s6 : ffffffe067d74e00 s7 : ffffffe067d74850
 s8 : ffffffe067d73e18 s9 : ffffffe067d74e00 s10: ffffffe00eef96e8
 s11: 000000ae6cdf8368 t3 : 5ae9db91c19bbe00 t4 : ffffffc4043cafb2
 t5 : ffffffc4043cafba t6 : 0000000000040000
status: 0000000000000120 badaddr: 000000002749f0d0 cause:
000000000000000f
Call Trace:
[<ffffffe00008c8b0>] schedule_tail+0x72/0xb2 kernel/sched/core.c:4264
[<ffffffe000005570>] ret_from_exception+0x0/0x14
Dumping ftrace buffer:
   (ftrace buffer empty)
---[ end trace b5f8f9231dc87dda ]---

The issue comes from the put_user() in schedule_tail
(kernel/sched/core.c) doing the following:

asmlinkage __visible void schedule_tail(struct task_struct *prev)
{
...
        if (current->set_child_tid)
                put_user(task_pid_vnr(current), current->set_child_tid);
...
}

the put_user() macro causes the code sequence to come out as follows:

1:	__enable_user_access()
2:	reg = task_pid_vnr(current);
3:	*current->set_child_tid = reg;
4:	__disable_user_access()

The problem is that we may have a sleeping function as argument which
could clear SR_SUM causing the panic above. This was fixed by
evaluating the argument of the put_user() macro outside the user-enabled
section in commit 285a76b ("riscv: evaluate put_user() arg before
enabling user access")"

In order for riscv to take advantage of unsafe_get/put_XXX() macros and
to avoid the same issue we had with put_user() and sleeping functions we
must ensure code flow can go through switch_to() from within a region of
code with SR_SUM enabled and come back with SR_SUM still enabled. This
patch addresses the problem allowing future work to enable full use of
unsafe_get/put_XXX() macros without needing to take a CSR bit flip cost
on every access. Make switch_to() save and restore SR_SUM.

Reported-by: syzbot+e74b94fe601ab9552d69@syzkaller.appspotmail.com
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Cyril Bur <cyrilbur@tenstorrent.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Deepak Gupta <debug@rivosinc.com>
Link: https://lore.kernel.org/r/20250410070526.3160847-2-cyrilbur@tenstorrent.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
l1k pushed a commit that referenced this pull request Jun 9, 2025
No device was set which caused serial_base_ctrl_add to crash.

 BUG: kernel NULL pointer dereference, address: 0000000000000050
 Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI
 CPU: 16 UID: 0 PID: 368 Comm: (udev-worker) Not tainted 6.12.25-amd64 #1  Debian 6.12.25-1
 RIP: 0010:serial_base_ctrl_add+0x96/0x120
 Call Trace:
  <TASK>
  serial_core_register_port+0x1a0/0x580
  ? __setup_irq+0x39c/0x660
  ? __kmalloc_cache_noprof+0x111/0x310
  jsm_uart_port_init+0xe8/0x180 [jsm]
  jsm_probe_one+0x1f4/0x410 [jsm]
  local_pci_probe+0x42/0x90
  pci_device_probe+0x22f/0x270
  really_probe+0xdb/0x340
  ? pm_runtime_barrier+0x54/0x90
  ? __pfx___driver_attach+0x10/0x10
  __driver_probe_device+0x78/0x110
  driver_probe_device+0x1f/0xa0
  __driver_attach+0xba/0x1c0
  bus_for_each_dev+0x8c/0xe0
  bus_add_driver+0x112/0x1f0
  driver_register+0x72/0xd0
  jsm_init_module+0x36/0xff0 [jsm]
  ? __pfx_jsm_init_module+0x10/0x10 [jsm]
  do_one_initcall+0x58/0x310
  do_init_module+0x60/0x230

Tested with Digi Neo PCIe 8 port card.

Fixes: 84a9582 ("serial: core: Start managing serial controllers to enable runtime PM")
Cc: stable <stable@kernel.org>
Signed-off-by: Dustin Lundquist <dustin@null-ptr.net>
Link: https://lore.kernel.org/r/3f31d4f75863614655c4673027a208be78d022ec.camel@null-ptr.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
l1k pushed a commit that referenced this pull request Jun 9, 2025
Syzkaller detected a kernel bug in jffs2_link_node_ref, caused by fault
injection in jffs2_prealloc_raw_node_refs. jffs2_sum_write_sumnode doesn't
check return value of jffs2_prealloc_raw_node_refs and simply lets any
error propagate into jffs2_sum_write_data, which eventually calls
jffs2_link_node_ref in order to link the summary to an expectedly allocated
node.

kernel BUG at fs/jffs2/nodelist.c:592!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 1 PID: 31277 Comm: syz-executor.7 Not tainted 6.1.128-syzkaller-00139-ge10f83ca10a1 #0
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
RIP: 0010:jffs2_link_node_ref+0x570/0x690 fs/jffs2/nodelist.c:592
Call Trace:
 <TASK>
 jffs2_sum_write_data fs/jffs2/summary.c:841 [inline]
 jffs2_sum_write_sumnode+0xd1a/0x1da0 fs/jffs2/summary.c:874
 jffs2_do_reserve_space+0xa18/0xd60 fs/jffs2/nodemgmt.c:388
 jffs2_reserve_space+0x55f/0xaa0 fs/jffs2/nodemgmt.c:197
 jffs2_write_inode_range+0x246/0xb50 fs/jffs2/write.c:362
 jffs2_write_end+0x726/0x15d0 fs/jffs2/file.c:301
 generic_perform_write+0x314/0x5d0 mm/filemap.c:3856
 __generic_file_write_iter+0x2ae/0x4d0 mm/filemap.c:3973
 generic_file_write_iter+0xe3/0x350 mm/filemap.c:4005
 call_write_iter include/linux/fs.h:2265 [inline]
 do_iter_readv_writev+0x20f/0x3c0 fs/read_write.c:735
 do_iter_write+0x186/0x710 fs/read_write.c:861
 vfs_iter_write+0x70/0xa0 fs/read_write.c:902
 iter_file_splice_write+0x73b/0xc90 fs/splice.c:685
 do_splice_from fs/splice.c:763 [inline]
 direct_splice_actor+0x10c/0x170 fs/splice.c:950
 splice_direct_to_actor+0x337/0xa10 fs/splice.c:896
 do_splice_direct+0x1a9/0x280 fs/splice.c:1002
 do_sendfile+0xb13/0x12c0 fs/read_write.c:1255
 __do_sys_sendfile64 fs/read_write.c:1323 [inline]
 __se_sys_sendfile64 fs/read_write.c:1309 [inline]
 __x64_sys_sendfile64+0x1cf/0x210 fs/read_write.c:1309
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x35/0x80 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x6e/0xd8

Fix this issue by checking return value of jffs2_prealloc_raw_node_refs
before calling jffs2_sum_write_data.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Cc: stable@vger.kernel.org
Fixes: 2f78540 ("[JFFS2] Reduce visibility of raw_node_ref to upper layers of JFFS2 code.")
Signed-off-by: Artem Sadovnikov <a.sadovnikov@ispras.ru>
Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
l1k pushed a commit that referenced this pull request Jun 9, 2025
1. LINE#1794 - LINE#1887 is some codes about function of
   bch_cache_set_alloc().
2. LINE#2078 - LINE#2142 is some codes about function of
   register_cache_set().
3. register_cache_set() will call bch_cache_set_alloc() in LINE#2098.

 1794 struct cache_set *bch_cache_set_alloc(struct cache_sb *sb)
 1795 {
 ...
 1860         if (!(c->devices = kcalloc(c->nr_uuids, sizeof(void *), GFP_KERNEL)) ||
 1861             mempool_init_slab_pool(&c->search, 32, bch_search_cache) ||
 1862             mempool_init_kmalloc_pool(&c->bio_meta, 2,
 1863                                 sizeof(struct bbio) + sizeof(struct bio_vec) *
 1864                                 bucket_pages(c)) ||
 1865             mempool_init_kmalloc_pool(&c->fill_iter, 1, iter_size) ||
 1866             bioset_init(&c->bio_split, 4, offsetof(struct bbio, bio),
 1867                         BIOSET_NEED_BVECS|BIOSET_NEED_RESCUER) ||
 1868             !(c->uuids = alloc_bucket_pages(GFP_KERNEL, c)) ||
 1869             !(c->moving_gc_wq = alloc_workqueue("bcache_gc",
 1870                                                 WQ_MEM_RECLAIM, 0)) ||
 1871             bch_journal_alloc(c) ||
 1872             bch_btree_cache_alloc(c) ||
 1873             bch_open_buckets_alloc(c) ||
 1874             bch_bset_sort_state_init(&c->sort, ilog2(c->btree_pages)))
 1875                 goto err;
                      ^^^^^^^^
 1876
 ...
 1883         return c;
 1884 err:
 1885         bch_cache_set_unregister(c);
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 1886         return NULL;
 1887 }
 ...
 2078 static const char *register_cache_set(struct cache *ca)
 2079 {
 ...
 2098         c = bch_cache_set_alloc(&ca->sb);
 2099         if (!c)
 2100                 return err;
                      ^^^^^^^^^^
 ...
 2128         ca->set = c;
 2129         ca->set->cache[ca->sb.nr_this_dev] = ca;
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 ...
 2138         return NULL;
 2139 err:
 2140         bch_cache_set_unregister(c);
 2141         return err;
 2142 }

(1) If LINE#1860 - LINE#1874 is true, then do 'goto err'(LINE#1875) and
    call bch_cache_set_unregister()(LINE#1885).
(2) As (1) return NULL(LINE#1886), LINE#2098 - LINE#2100 would return.
(3) As (2) has returned, LINE#2128 - LINE#2129 would do *not* give the
    value to c->cache[], it means that c->cache[] is NULL.

LINE#1624 - LINE#1665 is some codes about function of cache_set_flush().
As (1), in LINE#1885 call
bch_cache_set_unregister()
---> bch_cache_set_stop()
     ---> closure_queue()
          -.-> cache_set_flush() (as below LINE#1624)

 1624 static void cache_set_flush(struct closure *cl)
 1625 {
 ...
 1654         for_each_cache(ca, c, i)
 1655                 if (ca->alloc_thread)
                          ^^
 1656                         kthread_stop(ca->alloc_thread);
 ...
 1665 }

(4) In LINE#1655 ca is NULL(see (3)) in cache_set_flush() then the
    kernel crash occurred as below:
[  846.712887] bcache: register_cache() error drbd6: cannot allocate memory
[  846.713242] bcache: register_bcache() error : failed to register device
[  846.713336] bcache: cache_set_free() Cache set 2f84bdc1-498a-4f2f-98a7-01946bf54287 unregistered
[  846.713768] BUG: unable to handle kernel NULL pointer dereference at 00000000000009f8
[  846.714790] PGD 0 P4D 0
[  846.715129] Oops: 0000 [#1] SMP PTI
[  846.715472] CPU: 19 PID: 5057 Comm: kworker/19:16 Kdump: loaded Tainted: G           OE    --------- -  - 4.18.0-147.5.1.el8_1.5es.3.x86_64 #1
[  846.716082] Hardware name: ESPAN GI-25212/X11DPL-i, BIOS 2.1 06/15/2018
[  846.716451] Workqueue: events cache_set_flush [bcache]
[  846.716808] RIP: 0010:cache_set_flush+0xc9/0x1b0 [bcache]
[  846.717155] Code: 00 4c 89 a5 b0 03 00 00 48 8b 85 68 f6 ff ff a8 08 0f 84 88 00 00 00 31 db 66 83 bd 3c f7 ff ff 00 48 8b 85 48 ff ff ff 74 28 <48> 8b b8 f8 09 00 00 48 85 ff 74 05 e8 b6 58 a2 e1 0f b7 95 3c f7
[  846.718026] RSP: 0018:ffffb56dcf85fe70 EFLAGS: 00010202
[  846.718372] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[  846.718725] RDX: 0000000000000001 RSI: 0000000040000001 RDI: 0000000000000000
[  846.719076] RBP: ffffa0ccc0f20df8 R08: ffffa0ce1fedb118 R09: 000073746e657665
[  846.719428] R10: 8080808080808080 R11: 0000000000000000 R12: ffffa0ce1fee8700
[  846.719779] R13: ffffa0ccc0f211a8 R14: ffffa0cd1b902840 R15: ffffa0ccc0f20e00
[  846.720132] FS:  0000000000000000(0000) GS:ffffa0ce1fec0000(0000) knlGS:0000000000000000
[  846.720726] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  846.721073] CR2: 00000000000009f8 CR3: 00000008ba00a005 CR4: 00000000007606e0
[  846.721426] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  846.721778] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  846.722131] PKRU: 55555554
[  846.722467] Call Trace:
[  846.722814]  process_one_work+0x1a7/0x3b0
[  846.723157]  worker_thread+0x30/0x390
[  846.723501]  ? create_worker+0x1a0/0x1a0
[  846.723844]  kthread+0x112/0x130
[  846.724184]  ? kthread_flush_work_fn+0x10/0x10
[  846.724535]  ret_from_fork+0x35/0x40

Now, check whether that ca is NULL in LINE#1655 to fix the issue.

Signed-off-by: Linggang Zeng <linggang.zeng@easystack.cn>
Signed-off-by: Mingzhe Zou <mingzhe.zou@easystack.cn>
Signed-off-by: Coly Li <colyli@kernel.org>
Link: https://lore.kernel.org/r/20250527051601.74407-2-colyli@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
l1k pushed a commit that referenced this pull request Jun 9, 2025
When the XDP program is loaded, the XDP callback adds new Tx queues.
This means that the callback must update the Tx scheduler with the new
queue number. In the event of a Tx scheduler failure, the XDP callback
should also fail and roll back any changes previously made for XDP
preparation.

The previous implementation had a bug that not all changes made by the
XDP callback were rolled back. This caused the crash with the following
call trace:

[  +9.549584] ice 0000:ca:00.0: Failed VSI LAN queue config for XDP, error: -5
[  +0.382335] Oops: general protection fault, probably for non-canonical address 0x50a2250a90495525: 0000 [#1] SMP NOPTI
[  +0.010710] CPU: 103 UID: 0 PID: 0 Comm: swapper/103 Not tainted 6.14.0-net-next-mar-31+ torvalds#14 PREEMPT(voluntary)
[  +0.010175] Hardware name: Intel Corporation M50CYP2SBSTD/M50CYP2SBSTD, BIOS SE5C620.86B.01.01.0005.2202160810 02/16/2022
[  +0.010946] RIP: 0010:__ice_update_sample+0x39/0xe0 [ice]

[...]

[  +0.002715] Call Trace:
[  +0.002452]  <IRQ>
[  +0.002021]  ? __die_body.cold+0x19/0x29
[  +0.003922]  ? die_addr+0x3c/0x60
[  +0.003319]  ? exc_general_protection+0x17c/0x400
[  +0.004707]  ? asm_exc_general_protection+0x26/0x30
[  +0.004879]  ? __ice_update_sample+0x39/0xe0 [ice]
[  +0.004835]  ice_napi_poll+0x665/0x680 [ice]
[  +0.004320]  __napi_poll+0x28/0x190
[  +0.003500]  net_rx_action+0x198/0x360
[  +0.003752]  ? update_rq_clock+0x39/0x220
[  +0.004013]  handle_softirqs+0xf1/0x340
[  +0.003840]  ? sched_clock_cpu+0xf/0x1f0
[  +0.003925]  __irq_exit_rcu+0xc2/0xe0
[  +0.003665]  common_interrupt+0x85/0xa0
[  +0.003839]  </IRQ>
[  +0.002098]  <TASK>
[  +0.002106]  asm_common_interrupt+0x26/0x40
[  +0.004184] RIP: 0010:cpuidle_enter_state+0xd3/0x690

Fix this by performing the missing unmapping of XDP queues from
q_vectors and setting the XDP rings pointer back to NULL after all those
queues are released.
Also, add an immediate exit from the XDP callback in case of ring
preparation failure.

Fixes: efc2214 ("ice: Add support for XDP")
Reviewed-by: Dawid Osuchowski <dawid.osuchowski@linux.intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Michal Kubiak <michal.kubiak@intel.com>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Jesse Brandeburg <jbrandeburg@cloudflare.com>
Tested-by: Saritha Sanigani <sarithax.sanigani@intel.com> (A Contingent Worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
l1k pushed a commit that referenced this pull request Jun 9, 2025
The generic/397 test hits a BUG_ON for the case of encrypted inode with
unaligned file size (for example, 33K or 1K):

[ 877.737811] run fstests generic/397 at 2025-01-03 12:34:40
[ 877.875761] libceph: mon0 (2)127.0.0.1:40674 session established
[ 877.876130] libceph: client4614 fsid 19b90bca-f1ae-47a6-93dd-0b03ee637949
[ 877.991965] libceph: mon0 (2)127.0.0.1:40674 session established
[ 877.992334] libceph: client4617 fsid 19b90bca-f1ae-47a6-93dd-0b03ee637949
[ 878.017234] libceph: mon0 (2)127.0.0.1:40674 session established
[ 878.017594] libceph: client4620 fsid 19b90bca-f1ae-47a6-93dd-0b03ee637949
[ 878.031394] xfs_io (pid 18988) is setting deprecated v1 encryption policy; recommend upgrading to v2.
[ 878.054528] libceph: mon0 (2)127.0.0.1:40674 session established
[ 878.054892] libceph: client4623 fsid 19b90bca-f1ae-47a6-93dd-0b03ee637949
[ 878.070287] libceph: mon0 (2)127.0.0.1:40674 session established
[ 878.070704] libceph: client4626 fsid 19b90bca-f1ae-47a6-93dd-0b03ee637949
[ 878.264586] libceph: mon0 (2)127.0.0.1:40674 session established
[ 878.265258] libceph: client4629 fsid 19b90bca-f1ae-47a6-93dd-0b03ee637949
[ 878.374578] -----------[ cut here ]------------
[ 878.374586] kernel BUG at net/ceph/messenger.c:1070!
[ 878.375150] Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
[ 878.378145] CPU: 2 UID: 0 PID: 4759 Comm: kworker/2:9 Not tainted 6.13.0-rc5+ #1
[ 878.378969] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[ 878.380167] Workqueue: ceph-msgr ceph_con_workfn
[ 878.381639] RIP: 0010:ceph_msg_data_cursor_init+0x42/0x50
[ 878.382152] Code: 89 17 48 8b 46 70 55 48 89 47 08 c7 47 18 00 00 00 00 48 89 e5 e8 de cc ff ff 5d 31 c0 31 d2 31 f6 31 ff c3 cc cc cc cc 0f 0b <0f> 0b 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90
[ 878.383928] RSP: 0018:ffffb4ffc7cbbd28 EFLAGS: 00010287
[ 878.384447] RAX: ffffffff82bb9ac0 RBX: ffff981390c2f1f8 RCX: 0000000000000000
[ 878.385129] RDX: 0000000000009000 RSI: ffff981288232b58 RDI: ffff981390c2f378
[ 878.385839] RBP: ffffb4ffc7cbbe18 R08: 0000000000000000 R09: 0000000000000000
[ 878.386539] R10: 0000000000000000 R11: 0000000000000000 R12: ffff981390c2f030
[ 878.387203] R13: ffff981288232b58 R14: 0000000000000029 R15: 0000000000000001
[ 878.387877] FS: 0000000000000000(0000) GS:ffff9814b7900000(0000) knlGS:0000000000000000
[ 878.388663] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 878.389212] CR2: 00005e106a0554e0 CR3: 0000000112bf0001 CR4: 0000000000772ef0
[ 878.389921] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 878.390620] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 878.391307] PKRU: 55555554
[ 878.391567] Call Trace:
[ 878.391807] <TASK>
[ 878.392021] ? show_regs+0x71/0x90
[ 878.392391] ? die+0x38/0xa0
[ 878.392667] ? do_trap+0xdb/0x100
[ 878.392981] ? do_error_trap+0x75/0xb0
[ 878.393372] ? ceph_msg_data_cursor_init+0x42/0x50
[ 878.393842] ? exc_invalid_op+0x53/0x80
[ 878.394232] ? ceph_msg_data_cursor_init+0x42/0x50
[ 878.394694] ? asm_exc_invalid_op+0x1b/0x20
[ 878.395099] ? ceph_msg_data_cursor_init+0x42/0x50
[ 878.395583] ? ceph_con_v2_try_read+0xd16/0x2220
[ 878.396027] ? _raw_spin_unlock+0xe/0x40
[ 878.396428] ? raw_spin_rq_unlock+0x10/0x40
[ 878.396842] ? finish_task_switch.isra.0+0x97/0x310
[ 878.397338] ? __schedule+0x44b/0x16b0
[ 878.397738] ceph_con_workfn+0x326/0x750
[ 878.398121] process_one_work+0x188/0x3d0
[ 878.398522] ? __pfx_worker_thread+0x10/0x10
[ 878.398929] worker_thread+0x2b5/0x3c0
[ 878.399310] ? __pfx_worker_thread+0x10/0x10
[ 878.399727] kthread+0xe1/0x120
[ 878.400031] ? __pfx_kthread+0x10/0x10
[ 878.400431] ret_from_fork+0x43/0x70
[ 878.400771] ? __pfx_kthread+0x10/0x10
[ 878.401127] ret_from_fork_asm+0x1a/0x30
[ 878.401543] </TASK>
[ 878.401760] Modules linked in: hctr2 nhpoly1305_avx2 nhpoly1305_sse2 nhpoly1305 chacha_generic chacha_x86_64 libchacha adiantum libpoly1305 essiv authenc mptcp_diag xsk_diag tcp_diag udp_diag raw_diag inet_diag unix_diag af_packet_diag netlink_diag intel_rapl_msr intel_rapl_common intel_uncore_frequency_common skx_edac_common nfit kvm_intel kvm crct10dif_pclmul crc32_pclmul polyval_clmulni polyval_generic ghash_clmulni_intel sha256_ssse3 sha1_ssse3 aesni_intel joydev crypto_simd cryptd rapl input_leds psmouse sch_fq_codel serio_raw bochs i2c_piix4 floppy qemu_fw_cfg i2c_smbus mac_hid pata_acpi msr parport_pc ppdev lp parport efi_pstore ip_tables x_tables
[ 878.407319] ---[ end trace 0000000000000000 ]---
[ 878.407775] RIP: 0010:ceph_msg_data_cursor_init+0x42/0x50
[ 878.408317] Code: 89 17 48 8b 46 70 55 48 89 47 08 c7 47 18 00 00 00 00 48 89 e5 e8 de cc ff ff 5d 31 c0 31 d2 31 f6 31 ff c3 cc cc cc cc 0f 0b <0f> 0b 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90
[ 878.410087] RSP: 0018:ffffb4ffc7cbbd28 EFLAGS: 00010287
[ 878.410609] RAX: ffffffff82bb9ac0 RBX: ffff981390c2f1f8 RCX: 0000000000000000
[ 878.411318] RDX: 0000000000009000 RSI: ffff981288232b58 RDI: ffff981390c2f378
[ 878.412014] RBP: ffffb4ffc7cbbe18 R08: 0000000000000000 R09: 0000000000000000
[ 878.412735] R10: 0000000000000000 R11: 0000000000000000 R12: ffff981390c2f030
[ 878.413438] R13: ffff981288232b58 R14: 0000000000000029 R15: 0000000000000001
[ 878.414121] FS: 0000000000000000(0000) GS:ffff9814b7900000(0000) knlGS:0000000000000000
[ 878.414935] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 878.415516] CR2: 00005e106a0554e0 CR3: 0000000112bf0001 CR4: 0000000000772ef0
[ 878.416211] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 878.416907] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 878.417630] PKRU: 55555554

(gdb) l *ceph_msg_data_cursor_init+0x42
0xffffffff823b45a2 is in ceph_msg_data_cursor_init (net/ceph/messenger.c:1070).
1065
1066 void ceph_msg_data_cursor_init(struct ceph_msg_data_cursor *cursor,
1067                                struct ceph_msg *msg, size_t length)
1068 {
1069        BUG_ON(!length);
1070        BUG_ON(length > msg->data_length);
1071        BUG_ON(!msg->num_data_items);
1072
1073        cursor->total_resid = length;
1074        cursor->data = msg->data;

The issue takes place because of this:

[ 202.628853] libceph: net/ceph/messenger_v2.c:2034 prepare_sparse_read_data(): msg->data_length 33792, msg->sparse_read_total 36864

1070        BUG_ON(length > msg->data_length);

The generic/397 test (xfstests) executes such steps:
(1) create encrypted files and directories;
(2) access the created files and folders with encryption key;
(3) access the created files and folders without encryption key.

The issue takes place in this portion of code:

    if (IS_ENCRYPTED(inode)) {
            struct page **pages;
            size_t page_off;

            err = iov_iter_get_pages_alloc2(&subreq->io_iter, &pages, len,
                                            &page_off);
            if (err < 0) {
                    doutc(cl, "%llx.%llx failed to allocate pages, %d\n",
                          ceph_vinop(inode), err);
                    goto out;
            }

            /* should always give us a page-aligned read */
            WARN_ON_ONCE(page_off);
            len = err;
            err = 0;

            osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0, false,
                                             false);

The reason of the issue is that subreq->io_iter.count keeps unaligned
value of length:

[  347.751182] lib/iov_iter.c:1185 __iov_iter_get_pages_alloc(): maxsize 36864, maxpages 4294967295, start 18446659367320516064
[  347.752808] lib/iov_iter.c:1196 __iov_iter_get_pages_alloc(): maxsize 33792, maxpages 4294967295, start 18446659367320516064
[  347.754394] lib/iov_iter.c:1015 iter_folioq_get_pages(): maxsize 33792, maxpages 4294967295, extracted 0, _start_offset 18446659367320516064

This patch simply assigns the aligned value to subreq->io_iter.count
before calling iov_iter_get_pages_alloc2().

[ idryomov: tag the comment with FIXME to make it clear that it's only
            a workaround for netfslib not coexisting with fscrypt nicely
            (this is also noted in another pre-existing comment) ]

Cc: David Howells <dhowells@redhat.com>
Cc: stable@vger.kernel.org
Fixes: ee4cdf7 ("netfs: Speed up buffered reading")
Signed-off-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
l1k pushed a commit that referenced this pull request Jun 9, 2025
Commit a1e40ac ("net: gso: fix udp gso fraglist segmentation after
pull from frag_list") detected invalid geometry in frag_list skbs and
redirects them from skb_segment_list to more robust skb_segment. But some
packets with modified geometry can also hit bugs in that code. We don't
know how many such cases exist. Addressing each one by one also requires
touching the complex skb_segment code, which risks introducing bugs for
other types of skbs. Instead, linearize all these packets that fail the
basic invariants on gso fraglist skbs. That is more robust.

If only part of the fraglist payload is pulled into head_skb, it will
always cause exception when splitting skbs by skb_segment. For detailed
call stack information, see below.

Valid SKB_GSO_FRAGLIST skbs
- consist of two or more segments
- the head_skb holds the protocol headers plus first gso_size
- one or more frag_list skbs hold exactly one segment
- all but the last must be gso_size

Optional datapath hooks such as NAT and BPF (bpf_skb_pull_data) can
modify fraglist skbs, breaking these invariants.

In extreme cases they pull one part of data into skb linear. For UDP,
this  causes three payloads with lengths of (11,11,10) bytes were
pulled tail to become (12,10,10) bytes.

The skbs no longer meets the above SKB_GSO_FRAGLIST conditions because
payload was pulled into head_skb, it needs to be linearized before pass
to regular skb_segment.

    skb_segment+0xcd0/0xd14
    __udp_gso_segment+0x334/0x5f4
    udp4_ufo_fragment+0x118/0x15c
    inet_gso_segment+0x164/0x338
    skb_mac_gso_segment+0xc4/0x13c
    __skb_gso_segment+0xc4/0x124
    validate_xmit_skb+0x9c/0x2c0
    validate_xmit_skb_list+0x4c/0x80
    sch_direct_xmit+0x70/0x404
    __dev_queue_xmit+0x64c/0xe5c
    neigh_resolve_output+0x178/0x1c4
    ip_finish_output2+0x37c/0x47c
    __ip_finish_output+0x194/0x240
    ip_finish_output+0x20/0xf4
    ip_output+0x100/0x1a0
    NF_HOOK+0xc4/0x16c
    ip_forward+0x314/0x32c
    ip_rcv+0x90/0x118
    __netif_receive_skb+0x74/0x124
    process_backlog+0xe8/0x1a4
    __napi_poll+0x5c/0x1f8
    net_rx_action+0x154/0x314
    handle_softirqs+0x154/0x4b8

    [118.376811] [C201134] rxq0_pus: [name:bug&]kernel BUG at net/core/skbuff.c:4278!
    [118.376829] [C201134] rxq0_pus: [name:traps&]Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
    [118.470774] [C201134] rxq0_pus: [name:mrdump&]Kernel Offset: 0x178cc00000 from 0xffffffc008000000
    [118.470810] [C201134] rxq0_pus: [name:mrdump&]PHYS_OFFSET: 0x40000000
    [118.470827] [C201134] rxq0_pus: [name:mrdump&]pstate: 60400005 (nZCv daif +PAN -UAO)
    [118.470848] [C201134] rxq0_pus: [name:mrdump&]pc : [0xffffffd79598aefc] skb_segment+0xcd0/0xd14
    [118.470900] [C201134] rxq0_pus: [name:mrdump&]lr : [0xffffffd79598a5e8] skb_segment+0x3bc/0xd14
    [118.470928] [C201134] rxq0_pus: [name:mrdump&]sp : ffffffc008013770

Fixes: a1e40ac ("gso: fix udp gso fraglist segmentation after pull from frag_list")
Signed-off-by: Shiming Cheng <shiming.cheng@mediatek.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
l1k pushed a commit that referenced this pull request Jun 9, 2025
When driver handles the napi rx polling requests, the netdev might
have been released by the dellink logic triggered by the disconnect
operation on user plane. However, in the logic of processing skb in
polling, an invalid netdev is still being used, which causes a panic.

BUG: kernel NULL pointer dereference, address: 00000000000000f1
Oops: 0000 [#1] PREEMPT SMP NOPTI
RIP: 0010:dev_gro_receive+0x3a/0x620
[...]
Call Trace:
 <IRQ>
 ? __die_body+0x68/0xb0
 ? page_fault_oops+0x379/0x3e0
 ? exc_page_fault+0x4f/0xa0
 ? asm_exc_page_fault+0x22/0x30
 ? __pfx_t7xx_ccmni_recv_skb+0x10/0x10 [mtk_t7xx (HASH:1400 7)]
 ? dev_gro_receive+0x3a/0x620
 napi_gro_receive+0xad/0x170
 t7xx_ccmni_recv_skb+0x48/0x70 [mtk_t7xx (HASH:1400 7)]
 t7xx_dpmaif_napi_rx_poll+0x590/0x800 [mtk_t7xx (HASH:1400 7)]
 net_rx_action+0x103/0x470
 irq_exit_rcu+0x13a/0x310
 sysvec_apic_timer_interrupt+0x56/0x90
 </IRQ>

Fixes: 5545b7b ("net: wwan: t7xx: Add NAPI support")
Signed-off-by: Jinjian Song <jinjian.song@fibocom.com>
Link: https://patch.msgid.link/20250530031648.5592-1-jinjian.song@fibocom.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
l1k pushed a commit that referenced this pull request Jun 9, 2025
Removing a peer while userspace attempts to close its transport
socket triggers a race condition resulting in the following
crash:

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000077: 0000 [#1] SMP KASAN
KASAN: null-ptr-deref in range [0x00000000000003b8-0x00000000000003bf]
CPU: 12 UID: 0 PID: 162 Comm: kworker/12:1 Tainted: G           O        6.15.0-rc2-00635-g521139ac3840 torvalds#272 PREEMPT(full)
Tainted: [O]=OOT_MODULE
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-20240910_120124-localhost 04/01/2014
Workqueue: events ovpn_peer_keepalive_work [ovpn]
RIP: 0010:ovpn_socket_release+0x23c/0x500 [ovpn]
Code: ea 03 80 3c 02 00 0f 85 71 02 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 64 24 18 49 8d bc 24 be 03 00 00 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f 85 30
RSP: 0018:ffffc90000c9fb18 EFLAGS: 00010217
RAX: dffffc0000000000 RBX: ffff8881148d7940 RCX: ffffffff817787bb
RDX: 0000000000000077 RSI: 0000000000000008 RDI: 00000000000003be
RBP: ffffc90000c9fb30 R08: 0000000000000000 R09: fffffbfff0d3e840
R10: ffffffff869f4207 R11: 0000000000000000 R12: 0000000000000000
R13: ffff888115eb9300 R14: ffffc90000c9fbc8 R15: 000000000000000c
FS:  0000000000000000(0000) GS:ffff8882b0151000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f37266b6114 CR3: 00000000054a8000 CR4: 0000000000750ef0
PKRU: 55555554
Call Trace:
 <TASK>
 unlock_ovpn+0x8b/0xe0 [ovpn]
 ovpn_peer_keepalive_work+0xe3/0x540 [ovpn]
 ? ovpn_peers_free+0x780/0x780 [ovpn]
 ? lock_acquire+0x56/0x70
 ? process_one_work+0x888/0x1740
 process_one_work+0x933/0x1740
 ? pwq_dec_nr_in_flight+0x10b0/0x10b0
 ? move_linked_works+0x12d/0x2c0
 ? assign_work+0x163/0x270
 worker_thread+0x4d6/0xd90
 ? preempt_count_sub+0x4c/0x70
 ? process_one_work+0x1740/0x1740
 kthread+0x36c/0x710
 ? trace_preempt_on+0x8c/0x1e0
 ? kthread_is_per_cpu+0xc0/0xc0
 ? preempt_count_sub+0x4c/0x70
 ? _raw_spin_unlock_irq+0x36/0x60
 ? calculate_sigpending+0x7b/0xa0
 ? kthread_is_per_cpu+0xc0/0xc0
 ret_from_fork+0x3a/0x80
 ? kthread_is_per_cpu+0xc0/0xc0
 ret_from_fork_asm+0x11/0x20
 </TASK>
Modules linked in: ovpn(O)

This happens because the peer deletion operation reaches
ovpn_socket_release() while ovpn_sock->sock (struct socket *)
and its sk member (struct sock *) are still both valid.
Here synchronize_rcu() is invoked, after which ovpn_sock->sock->sk
becomes NULL, due to the concurrent socket closing triggered
from userspace.

After having invoked synchronize_rcu(), ovpn_socket_release() will
attempt dereferencing ovpn_sock->sock->sk, triggering the crash
reported above.

The reason for accessing sk is that we need to retrieve its
protocol and continue the cleanup routine accordingly.

This crash can be easily produced by running openvpn userspace in
client mode with `--keepalive 10 20`, while entirely omitting this
option on the server side.
After 20 seconds ovpn will assume the peer (server) to be dead,
will start removing it and will notify userspace. The latter will
receive the notification and close the transport socket, thus
triggering the crash.

To fix the race condition for good, we need to refactor struct ovpn_socket.
Since ovpn is always only interested in the sock->sk member (struct sock *)
we can directly hold a reference to it, raher than accessing it via
its struct socket container.

This means changing "struct socket *ovpn_socket->sock" to
"struct sock *ovpn_socket->sk".

While acquiring a reference to sk, we can increase its refcounter
without affecting the socket close()/destroy() notification
(which we rely on when userspace closes a socket we are using).

By increasing sk's refcounter we know we can dereference it
in ovpn_socket_release() without incurring in any race condition
anymore.

ovpn_socket_release() will ultimately decrease the reference
counter.

Cc: Oleksandr Natalenko <oleksandr@natalenko.name>
Fixes: 11851cb ("ovpn: implement TCP transport")
Reported-by: Qingfang Deng <dqfext@gmail.com>
Closes: OpenVPN#1
Tested-by: Gert Doering <gert@greenie.muc.de>
Link: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg31575.html
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Signed-off-by: Antonio Quartulli <antonio@openvpn.net>
l1k pushed a commit that referenced this pull request Jun 9, 2025
According to OpenMDK, bit 2 of the RGMII register has a different
meaning for BCM53115 [1]:

"DLL_IQQD         1: In the IDDQ mode, power is down0: Normal function
                  mode"

Configuring RGMII delay works without setting this bit, so let's keep it
at the default. For other chips, we always set it, so not clearing it
is not an issue.

One would assume BCM53118 works the same, but OpenMDK is not quite sure
what this bit actually means [2]:

"BYPASS_IMP_2NS_DEL #1: In the IDDQ mode, power is down#0: Normal
                    function mode1: Bypass dll65_2ns_del IP0: Use
                    dll65_2ns_del IP"

So lets keep setting it for now.

[1] https://github.com/Broadcom-Network-Switching-Software/OpenMDK/blob/master/cdk/PKG/chip/bcm53115/bcm53115_a0_defs.h#L19871
[2] https://github.com/Broadcom-Network-Switching-Software/OpenMDK/blob/master/cdk/PKG/chip/bcm53118/bcm53118_a0_defs.h#L14392

Fixes: 967dd82 ("net: dsa: b53: Add support for Broadcom RoboSwitch")
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Link: https://patch.msgid.link/20250602193953.1010487-6-jonas.gorski@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
l1k pushed a commit that referenced this pull request Jun 9, 2025
Kernel user spaces accesses to not exported pages in atomic context
incorrectly try to resolve the page fault.
With debug options enabled call traces like this can be seen:

BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1523
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 419074, name: qemu-system-s39
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
INFO: lockdep is turned off.
Preemption disabled at:
[<00000383ea47cfa2>] copy_page_from_iter_atomic+0xa2/0x8a0
CPU: 12 UID: 0 PID: 419074 Comm: qemu-system-s39
Tainted: G        W           6.16.0-20250531.rc0.git0.69b3a602feac.63.fc42.s390x+debug #1 PREEMPT
Tainted: [W]=WARN
Hardware name: IBM 3931 A01 703 (LPAR)
Call Trace:
 [<00000383e990d282>] dump_stack_lvl+0xa2/0xe8
 [<00000383e99bf152>] __might_resched+0x292/0x2d0
 [<00000383eaa7c374>] down_read+0x34/0x2d0
 [<00000383e99432f8>] do_secure_storage_access+0x108/0x360
 [<00000383eaa724b0>] __do_pgm_check+0x130/0x220
 [<00000383eaa842e4>] pgm_check_handler+0x114/0x160
 [<00000383ea47d028>] copy_page_from_iter_atomic+0x128/0x8a0
([<00000383ea47d016>] copy_page_from_iter_atomic+0x116/0x8a0)
 [<00000383e9c45eae>] generic_perform_write+0x16e/0x310
 [<00000383e9eb87f4>] ext4_buffered_write_iter+0x84/0x160
 [<00000383e9da0de4>] vfs_write+0x1c4/0x460
 [<00000383e9da123c>] ksys_write+0x7c/0x100
 [<00000383eaa7284e>] __do_syscall+0x15e/0x280
 [<00000383eaa8417e>] system_call+0x6e/0x90
INFO: lockdep is turned off.

It is not allowed to take the mmap_lock while in atomic context. Therefore
handle such a secure storage access fault as if the accessed page is not
mapped: the uaccess function will return -EFAULT, and the caller has to
deal with this. Usually this means that the access is retried in process
context, which allows to resolve the page fault (or in this case export the
page).

Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Link: https://lore.kernel.org/r/20250603134936.1314139-1-hca@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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4 participants