ASoC:core:bug fix: oops caused by pointer dereference #119
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added 2 commits
September 10, 2018 15:36
oops case:
the snd_card{} would be freed ahead of dynamic kcontrol
remove process, in this process, the snd_card{} will be
used, then the oops will be hit.
the solution:
the operation of removing the dynamic kcontrol should
be ahead of snd_card{} free.
Signed-off-by: Wu Zhigang <zhigang.wu@linux.intel.com>
remove the dynamic object during the topology free stage. to avoid multi remove operation. Signed-off-by: Wu Zhigang <zhigang.wu@linux.intel.com>
|
these two commits can fix the #97 |
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We've been seeing hard-to-trigger psi crashes when running inside VM
instances:
divide error: 0000 [#1] SMP PTI
Modules linked in: [...]
CPU: 0 PID: 212 Comm: kworker/0:2 Not tainted 4.16.18-119_fbk9_3817_gfe944c98d695 #119
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015
Workqueue: events psi_clock
RIP: 0010:psi_update_stats+0x270/0x490
RSP: 0018:ffffc90001117e10 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff8800a35a13f8
RDX: 0000000000000000 RSI: ffff8800a35a1340 RDI: 0000000000000000
RBP: 0000000000000658 R08: ffff8800a35a1470 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 00000000000f8502
FS: 0000000000000000(0000) GS:ffff88023fc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbe370fa000 CR3: 00000000b1e3a000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
psi_clock+0x12/0x50
process_one_work+0x1e0/0x390
worker_thread+0x2b/0x3c0
? rescuer_thread+0x330/0x330
kthread+0x113/0x130
? kthread_create_worker_on_cpu+0x40/0x40
? SyS_exit_group+0x10/0x10
ret_from_fork+0x35/0x40
Code: 48 0f 47 c7 48 01 c2 45 85 e4 48 89 16 0f 85 e6 00 00 00 4c 8b 49 10 4c 8b 51 08 49 69 d9 f2 07 00 00 48 6b c0 64 4c 8b 29 31 d2 <48> f7 f7 49 69 d5 8d 06 00 00 48 89 c5 4c 69 f0 00 98 0b 00 48
The Code-line points to `period` being 0 inside update_stats(), and we
divide by that when calculating that period's pressure percentage.
The elapsed period should never be 0. The reason this can happen is due
to an off-by-one in the idle time / missing period calculation combined
with a coarse sched_clock() in the virtual machine.
The target time for aggregation is advanced into the future on a fixed
grid to prevent clock drift. So when an aggregation runs after some idle
period, we can not just set it to "now + psi_period", but have to
calculate the downtime and advance the target time relative to itself.
However, if the aggregator was disabled exactly one psi_period (ns), we
drop one idle period in the calculation due to a > when we should do >=.
In that case, next_update will be advanced from 'now - psi_period' to
'now' when it should be moved to 'now + psi_period'. The run finishes
with last_update == next_update == sched_clock().
With hardware clocks, this exact nanosecond match isn't likely in the
first place; but if it does happen, the clock will still have moved on and
the period non-zero by the time the worker runs. A pointlessly short
period, but besides the extra work, no harm no foul. However, a slow
sched_clock() like we have on VMs might not have advanced either by the
time the worker runs again. And when we calculate the elapsed period, the
result, our pressure divisor, will be 0. Ouch.
Fix this by correctly handling the situation when the elapsed time between
aggregation runs is precisely two periods, and advance the expiration
timestamp correctly to period into the future.
Link: http://lkml.kernel.org/r/20190214193157.15788-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Łukasz Siudut <lsiudut@fb.com
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
plbossart
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Oct 9, 2019
Commit 5cf4537 ("dma-mapping: introduce a dma_common_find_pages helper") changed invalid input check in dma_common_free_remap() from: if (!area || !area->flags != VM_DMA_COHERENT) to if (!area || !area->flags != VM_DMA_COHERENT || !area->pages) which seem to produce false positives for memory obtained via dma_common_contiguous_remap() This triggers the following warning message when doing "reboot" on ZII VF610 Dev Board Rev B: WARNING: CPU: 0 PID: 1 at kernel/dma/remap.c:112 dma_common_free_remap+0x88/0x8c trying to free invalid coherent area: 9ef82980 Modules linked in: CPU: 0 PID: 1 Comm: systemd-shutdow Not tainted 5.3.0-rc6-next-20190820 #119 Hardware name: Freescale Vybrid VF5xx/VF6xx (Device Tree) Backtrace: [<8010d1ec>] (dump_backtrace) from [<8010d588>] (show_stack+0x20/0x24) r7:8015ed78 r6:00000009 r5:00000000 r4:9f4d9b14 [<8010d568>] (show_stack) from [<8077e3f0>] (dump_stack+0x24/0x28) [<8077e3cc>] (dump_stack) from [<801197a0>] (__warn.part.3+0xcc/0xe4) [<801196d4>] (__warn.part.3) from [<80119830>] (warn_slowpath_fmt+0x78/0x94) r6:00000070 r5:808e540c r4:81c03048 [<801197bc>] (warn_slowpath_fmt) from [<8015ed78>] (dma_common_free_remap+0x88/0x8c) r3:9ef82980 r2:808e53e0 r7:00001000 r6:a0b1e000 r5:a0b1e000 r4:00001000 [<8015ecf0>] (dma_common_free_remap) from [<8010fa9c>] (remap_allocator_free+0x60/0x68) r5:81c03048 r4:9f4d9b78 [<8010fa3c>] (remap_allocator_free) from [<801100d0>] (__arm_dma_free.constprop.3+0xf8/0x148) r5:81c03048 r4:9ef82900 [<8010ffd8>] (__arm_dma_free.constprop.3) from [<80110144>] (arm_dma_free+0x24/0x2c) r5:9f563410 r4:80110120 [<80110120>] (arm_dma_free) from [<8015d80c>] (dma_free_attrs+0xa0/0xdc) [<8015d76c>] (dma_free_attrs) from [<8020f3e4>] (dma_pool_destroy+0xc0/0x154) r8:9efa8860 r7:808f02f0 r6:808f02d0 r5:9ef82880 r4:9ef82780 [<8020f324>] (dma_pool_destroy) from [<805525d0>] (ehci_mem_cleanup+0x6c/0x150) r7:9f563410 r6:9efa8810 r5:00000000 r4:9efd0148 [<80552564>] (ehci_mem_cleanup) from [<80558e0c>] (ehci_stop+0xac/0xc0) r5:9efd0148 r4:9efd0000 [<80558d60>] (ehci_stop) from [<8053c4bc>] (usb_remove_hcd+0xf4/0x1b0) r7:9f563410 r6:9efd0074 r5:81c03048 r4:9efd0000 [<8053c3c8>] (usb_remove_hcd) from [<8056361c>] (host_stop+0x48/0xb8) r7:9f563410 r6:9efd0000 r5:9f5f4040 r4:9f5f5040 [<805635d4>] (host_stop) from [<80563d0c>] (ci_hdrc_host_destroy+0x34/0x38) r7:9f563410 r6:9f5f5040 r5:9efa8800 r4:9f5f4040 [<80563cd8>] (ci_hdrc_host_destroy) from [<8055ef18>] (ci_hdrc_remove+0x50/0x10c) [<8055eec8>] (ci_hdrc_remove) from [<804a2ed8>] (platform_drv_remove+0x34/0x4c) r7:9f563410 r6:81c4f99c r5:9efa8810 r4:9efa8810 [<804a2ea4>] (platform_drv_remove) from [<804a18a8>] (device_release_driver_internal+0xec/0x19c) r5:00000000 r4:9efa8810 [<804a17bc>] (device_release_driver_internal) from [<804a1978>] (device_release_driver+0x20/0x24) r7:9f563410 r6:81c41ed0 r5:9efa8810 r4:9f4a1dac [<804a1958>] (device_release_driver) from [<804a01b8>] (bus_remove_device+0xdc/0x108) [<804a00dc>] (bus_remove_device) from [<8049c204>] (device_del+0x150/0x36c) r7:9f563410 r6:81c03048 r5:9efa8854 r4:9efa8810 [<8049c0b4>] (device_del) from [<804a3368>] (platform_device_del.part.2+0x20/0x84) r10:9f563414 r9:809177e0 r8:81cb07dc r7:81c78320 r6:9f563454 r5:9efa8800 r4:9efa8800 [<804a3348>] (platform_device_del.part.2) from [<804a3420>] (platform_device_unregister+0x28/0x34) r5:9f563400 r4:9efa8800 [<804a33f8>] (platform_device_unregister) from [<8055dce0>] (ci_hdrc_remove_device+0x1c/0x30) r5:9f563400 r4:00000001 [<8055dcc4>] (ci_hdrc_remove_device) from [<805652ac>] (ci_hdrc_imx_remove+0x38/0x118) r7:81c78320 r6:9f563454 r5:9f563410 r4:9f541010 [<8056538c>] (ci_hdrc_imx_shutdown) from [<804a2970>] (platform_drv_shutdown+0x2c/0x30) [<804a2944>] (platform_drv_shutdown) from [<8049e4fc>] (device_shutdown+0x158/0x1f0) [<8049e3a4>] (device_shutdown) from [<8013ac80>] (kernel_restart_prepare+0x44/0x48) r10:00000058 r9:9f4d8000 r8:fee1dead r7:379ce700 r6:81c0b280 r5:81c03048 r4:00000000 [<8013ac3c>] (kernel_restart_prepare) from [<8013ad14>] (kernel_restart+0x1c/0x60) [<8013acf8>] (kernel_restart) from [<8013af84>] (__do_sys_reboot+0xe0/0x1d8) r5:81c03048 r4:00000000 [<8013aea4>] (__do_sys_reboot) from [<8013b0ec>] (sys_reboot+0x18/0x1c) r8:80101204 r7:00000058 r6:00000000 r5:00000000 r4:00000000 [<8013b0d4>] (sys_reboot) from [<80101000>] (ret_fast_syscall+0x0/0x54) Exception stack(0x9f4d9fa8 to 0x9f4d9ff0) 9fa0: 00000000 00000000 fee1dead 28121969 01234567 379ce700 9fc0: 00000000 00000000 00000000 00000058 00000000 00000000 00000000 00016d04 9fe0: 00028e0c 7ec87c64 000135ec 76c1f410 Restore original invalid input check in dma_common_free_remap() to avoid this problem. Fixes: 5cf4537 ("dma-mapping: introduce a dma_common_find_pages helper") Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> [hch: just revert the offending hunk instead of creating a new helper] Signed-off-by: Christoph Hellwig <hch@lst.de>
cujomalainey
pushed a commit
to cujomalainey/linux
that referenced
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Oct 26, 2020
We've been seeing hard-to-trigger psi crashes when running inside VM
instances:
divide error: 0000 [#1] SMP PTI
Modules linked in: [...]
CPU: 0 PID: 212 Comm: kworker/0:2 Not tainted 4.16.18-119_fbk9_3817_gfe944c98d695 thesofproject#119
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015
Workqueue: events psi_clock
RIP: 0010:psi_update_stats+0x270/0x490
RSP: 0018:ffffc90001117e10 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff8800a35a13f8
RDX: 0000000000000000 RSI: ffff8800a35a1340 RDI: 0000000000000000
RBP: 0000000000000658 R08: ffff8800a35a1470 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 00000000000f8502
FS: 0000000000000000(0000) GS:ffff88023fc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbe370fa000 CR3: 00000000b1e3a000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
psi_clock+0x12/0x50
process_one_work+0x1e0/0x390
worker_thread+0x2b/0x3c0
? rescuer_thread+0x330/0x330
kthread+0x113/0x130
? kthread_create_worker_on_cpu+0x40/0x40
? SyS_exit_group+0x10/0x10
ret_from_fork+0x35/0x40
Code: 48 0f 47 c7 48 01 c2 45 85 e4 48 89 16 0f 85 e6 00 00 00 4c 8b 49 10 4c 8b 51 08 49 69 d9 f2 07 00 00 48 6b c0 64 4c 8b 29 31 d2 <48> f7 f7 49 69 d5 8d 06 00 00 48 89 c5 4c 69 f0 00 98 0b 00 48
The Code-line points to `period` being 0 inside update_stats(), and we
divide by that when calculating that period's pressure percentage.
The elapsed period should never be 0. The reason this can happen is due
to an off-by-one in the idle time / missing period calculation combined
with a coarse sched_clock() in the virtual machine.
The target time for aggregation is advanced into the future on a fixed
grid to prevent clock drift. So when an aggregation runs after some idle
period, we can not just set it to "now + psi_period", but have to
calculate the downtime and advance the target time relative to itself.
However, if the aggregator was disabled exactly one psi_period (ns), we
drop one idle period in the calculation due to a > when we should do >=.
In that case, next_update will be advanced from 'now - psi_period' to
'now' when it should be moved to 'now + psi_period'. The run finishes
with last_update == next_update == sched_clock().
With hardware clocks, this exact nanosecond match isn't likely in the
first place; but if it does happen, the clock will still have moved on and
the period non-zero by the time the worker runs. A pointlessly short
period, but besides the extra work, no harm no foul. However, a slow
sched_clock() like we have on VMs might not have advanced either by the
time the worker runs again. And when we calculate the elapsed period, the
result, our pressure divisor, will be 0. Ouch.
Fix this by correctly handling the situation when the elapsed time between
aggregation runs is precisely two periods, and advance the expiration
timestamp correctly to period into the future.
Link: http://lkml.kernel.org/r/20190214193157.15788-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Łukasz Siudut <lsiudut@fb.com
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 4e37504)
BUG=chromium:1028527
TEST=run the monitor example from PSI kernel documentation
Change-Id: I9ff70ed220ec488a4d89d429ef79ac5455c09c29
Signed-off-by: Kuo-Hsin Yang <vovoy@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/2423483
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Sonny Rao <sonnyrao@chromium.org>
aiChaoSONG
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May 6, 2021
fixed restructured text syntax warning in docs
vijendarmukunda
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to vijendarmukunda/linux
that referenced
this pull request
Feb 13, 2024
Like commit 1cf3bfc ("bpf: Support 64-bit pointers to kfuncs") for s390x, add support for 64-bit pointers to kfuncs for LoongArch. Since the infrastructure is already implemented in BPF core, the only thing need to be done is to override bpf_jit_supports_far_kfunc_call(). Before this change, several test_verifier tests failed: # ./test_verifier | grep # | grep FAIL thesofproject#119/p calls: invalid kfunc call: ptr_to_mem to struct with non-scalar FAIL thesofproject#120/p calls: invalid kfunc call: ptr_to_mem to struct with nesting depth > 4 FAIL thesofproject#121/p calls: invalid kfunc call: ptr_to_mem to struct with FAM FAIL thesofproject#122/p calls: invalid kfunc call: reg->type != PTR_TO_CTX FAIL thesofproject#123/p calls: invalid kfunc call: void * not allowed in func proto without mem size arg FAIL thesofproject#124/p calls: trigger reg2btf_ids[reg->type] for reg->type > __BPF_REG_TYPE_MAX FAIL thesofproject#125/p calls: invalid kfunc call: reg->off must be zero when passed to release kfunc FAIL thesofproject#126/p calls: invalid kfunc call: don't match first member type when passed to release kfunc FAIL thesofproject#127/p calls: invalid kfunc call: PTR_TO_BTF_ID with negative offset FAIL thesofproject#128/p calls: invalid kfunc call: PTR_TO_BTF_ID with variable offset FAIL thesofproject#129/p calls: invalid kfunc call: referenced arg needs refcounted PTR_TO_BTF_ID FAIL thesofproject#130/p calls: valid kfunc call: referenced arg needs refcounted PTR_TO_BTF_ID FAIL thesofproject#486/p map_kptr: ref: reference state created and released on xchg FAIL This is because the kfuncs in the loaded module are far away from __bpf_call_base: ffff800002009440 t bpf_kfunc_call_test_fail1 [bpf_testmod] 9000000002e128d8 T __bpf_call_base The offset relative to __bpf_call_base does NOT fit in s32, which breaks the assumption in BPF core. Enable bpf_jit_supports_far_kfunc_call() lifts this limit. Note that to reproduce the above result, tools/testing/selftests/bpf/config should be applied, and run the test with JIT enabled, unpriv BPF enabled. With this change, the test_verifier tests now all passed: # ./test_verifier ... Summary: 777 PASSED, 0 SKIPPED, 0 FAILED Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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oops case:
the snd_card{} would be freed ahead of dynamic kcontrol
remove process, in this process, the snd_card{} will be
used, then the oops will be hit.
the solution:
the operation of removing the dynamic kcontrol should
be ahead of snd_card{} free.