Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

mt6625l: some fixes for R2 internal WiFi driver #65

Closed
wants to merge 6 commits into from

Conversation

lexa2
Copy link

@lexa2 lexa2 commented Oct 19, 2019

Signed-off-by: Alexey Loukianov lx2@lexa2.ru

@lexa2 lexa2 changed the title [misc/mediatek] wlan_gen2: restore use of wakeup source in irq handler [misc/mediatek] Some fixes for R2 internal WiFi driver Oct 19, 2019
Copy link
Owner

@frank-w frank-w left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Looks good so far...have you tested function as builtin and module?

drivers/misc/Makefile Outdated Show resolved Hide resolved
@lexa2
Copy link
Author

lexa2 commented Oct 19, 2019

Re normalizing tags - sure, will do.

Signed-off-by: Alexey Loukianov <lx2@lexa2.ru>
Signed-off-by: Alexey Loukianov <lx2@lexa2.ru>
Original-Author: Nikolay Amiantov <ab@fmap.me>
Signed-off-by: Alexey Loukianov <lx2@lexa2.ru>
@lexa2 lexa2 changed the title [misc/mediatek] Some fixes for R2 internal WiFi driver mt6625l: some fixes for R2 internal WiFi driver Oct 25, 2019
@lexa2
Copy link
Author

lexa2 commented Oct 25, 2019

Normalization: done.

Signed-off-by: Alexey Loukianov <lx2@lexa2.ru>
Signed-off-by: Alexey Loukianov <lx2@lexa2.ru>
@lexa2
Copy link
Author

lexa2 commented Oct 25, 2019

Frank, I had updated this PR to match the current state of your 5.4-wifi branch. Please check if I had addressed all points from your comments and feel free to merge this one if everything seems to be more or less okay. Thanks.

@frank-w
Copy link
Owner

frank-w commented Oct 26, 2019

Hi
thanks for your work,have you found the memory issue? Had not time yet to test by myself :(

@lexa2
Copy link
Author

lexa2 commented Oct 26, 2019

Hadn't had any luck with tracing potentional memory corruption issue when built as a module - last time I was testing wifi as a module board had been working fine with 6 days uptime without any issues. So it seems to be hard to track intermittent issue.

Signed-off-by: Alexey Loukianov <lx2@lexa2.ru>
@frank-w
Copy link
Owner

frank-w commented Dec 11, 2019

already merged to 5.4-main, thank you ;)

@frank-w frank-w closed this Dec 11, 2019
frank-w pushed a commit that referenced this pull request Jun 1, 2020
After previous fix for zero extension test_verifier tests #65 and #66 now
fail. Before the fix we can see the alu32 mov op at insn 10

10: R0_w=map_value(id=0,off=0,ks=8,vs=8,imm=0)
    R1_w=invP(id=0,
              smin_value=4294967168,smax_value=4294967423,
              umin_value=4294967168,umax_value=4294967423,
              var_off=(0x0; 0x1ffffffff),
              s32_min_value=-2147483648,s32_max_value=2147483647,
              u32_min_value=0,u32_max_value=-1)
    R10=fp0 fp-8_w=mmmmmmmm
10: (bc) w1 = w1
11: R0_w=map_value(id=0,off=0,ks=8,vs=8,imm=0)
    R1_w=invP(id=0,
              smin_value=0,smax_value=2147483647,
              umin_value=0,umax_value=4294967295,
              var_off=(0x0; 0xffffffff),
              s32_min_value=-2147483648,s32_max_value=2147483647,
              u32_min_value=0,u32_max_value=-1)
    R10=fp0 fp-8_w=mmmmmmmm

After the fix at insn 10 because we have 's32_min_value < 0' the following
step 11 now has 'smax_value=U32_MAX' where before we pulled the s32_max_value
bound into the smax_value as seen above in 11 with smax_value=2147483647.

10: R0_w=map_value(id=0,off=0,ks=8,vs=8,imm=0)
    R1_w=inv(id=0,
             smin_value=4294967168,smax_value=4294967423,
             umin_value=4294967168,umax_value=4294967423,
             var_off=(0x0; 0x1ffffffff),
             s32_min_value=-2147483648, s32_max_value=2147483647,
             u32_min_value=0,u32_max_value=-1)
    R10=fp0 fp-8_w=mmmmmmmm
10: (bc) w1 = w1
11: R0_w=map_value(id=0,off=0,ks=8,vs=8,imm=0)
    R1_w=inv(id=0,
             smin_value=0,smax_value=4294967295,
             umin_value=0,umax_value=4294967295,
             var_off=(0x0; 0xffffffff),
             s32_min_value=-2147483648, s32_max_value=2147483647,
             u32_min_value=0, u32_max_value=-1)
    R10=fp0 fp-8_w=mmmmmmmm

The fall out of this is by the time we get to the failing instruction at
step 14 where previously we had the following:

14: R0_w=map_value(id=0,off=0,ks=8,vs=8,imm=0)
    R1_w=inv(id=0,
             smin_value=72057594021150720,smax_value=72057594029539328,
             umin_value=72057594021150720,umax_value=72057594029539328,
             var_off=(0xffffffff000000; 0xffffff),
             s32_min_value=-16777216,s32_max_value=-1,
             u32_min_value=-16777216,u32_max_value=-1)
    R10=fp0 fp-8_w=mmmmmmmm
14: (0f) r0 += r1

We now have,

14: R0_w=map_value(id=0,off=0,ks=8,vs=8,imm=0)
    R1_w=inv(id=0,
             smin_value=0,smax_value=72057594037927935,
             umin_value=0,umax_value=72057594037927935,
             var_off=(0x0; 0xffffffffffffff),
             s32_min_value=-2147483648,s32_max_value=2147483647,
             u32_min_value=0,u32_max_value=-1)
    R10=fp0 fp-8_w=mmmmmmmm
14: (0f) r0 += r1

In the original step 14 'smin_value=72057594021150720' this trips the logic
in the verifier function check_reg_sane_offset(),

 if (smin >= BPF_MAX_VAR_OFF || smin <= -BPF_MAX_VAR_OFF) {
	verbose(env, "value %lld makes %s pointer be out of bounds\n",
		smin, reg_type_str[type]);
	return false;
 }

Specifically, the 'smin <= -BPF_MAX_VAR_OFF' check. But with the fix
at step 14 we have bounds 'smin_value=0' so the above check is not tripped
because BPF_MAX_VAR_OFF=1<<29.

We have a smin_value=0 here because at step 10 the smaller smin_value=0 means
the subtractions at steps 11 and 12 bring the smin_value negative.

11: (17) r1 -= 2147483584
12: (17) r1 -= 2147483584
13: (77) r1 >>= 8

Then the shift clears the top bit and smin_value is set to 0. Note we still
have the smax_value in the fixed code so any reads will fail. An alternative
would be to have reg_sane_check() do both smin and smax value tests.

To fix the test we can omit the 'r1 >>=8' at line 13. This will change the
err string, but keeps the intention of the test as suggseted by the title,
"check after truncation of boundary-crossing range". If the verifier logic
changes a different value is likely to be thrown in the error or the error
will no longer be thrown forcing this test to be examined. With this change
we see the new state at step 13.

13: R0_w=map_value(id=0,off=0,ks=8,vs=8,imm=0)
    R1_w=invP(id=0,
              smin_value=-4294967168,smax_value=127,
              umin_value=0,umax_value=18446744073709551615,
              s32_min_value=-2147483648,s32_max_value=2147483647,
              u32_min_value=0,u32_max_value=-1)
    R10=fp0 fp-8_w=mmmmmmmm

Giving the expected out of bounds error, "value -4294967168 makes map_value
pointer be out of bounds" However, for unpriv case we see a different error
now because of the mixed signed bounds pointer arithmatic. This seems OK so
I've only added the unpriv_errstr for this. Another optino may have been to
do addition on r1 instead of subtraction but I favor the approach above
slightly.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/159077333942.6014.14004320043595756079.stgit@john-Precision-5820-Tower
frank-w pushed a commit that referenced this pull request Apr 25, 2021
commit b094961 upstream.

ncsi_rsp_handler_gc() allocates the filter arrays using GFP_KERNEL in
softirq context, causing the below backtrace. This allocation is only a
few dozen bytes during probing so allocate with GFP_ATOMIC instead.

[   42.813372] BUG: sleeping function called from invalid context at mm/slab.h:416
[   42.820900] in_atomic(): 1, irqs_disabled(): 0, pid: 213, name: kworker/0:1
[   42.827893] INFO: lockdep is turned off.
[   42.832023] CPU: 0 PID: 213 Comm: kworker/0:1 Tainted: G        W       4.13.16-01441-gad99b38 #65
[   42.841007] Hardware name: Generic DT based system
[   42.845966] Workqueue: events ncsi_dev_work
[   42.850251] [<8010a494>] (unwind_backtrace) from [<80107510>] (show_stack+0x20/0x24)
[   42.858046] [<80107510>] (show_stack) from [<80612770>] (dump_stack+0x20/0x28)
[   42.865309] [<80612770>] (dump_stack) from [<80148248>] (___might_sleep+0x230/0x2b0)
[   42.873241] [<80148248>] (___might_sleep) from [<80148334>] (__might_sleep+0x6c/0xac)
[   42.881129] [<80148334>] (__might_sleep) from [<80240d6c>] (__kmalloc+0x210/0x2fc)
[   42.888737] [<80240d6c>] (__kmalloc) from [<8060ad54>] (ncsi_rsp_handler_gc+0xd0/0x170)
[   42.896770] [<8060ad54>] (ncsi_rsp_handler_gc) from [<8060b454>] (ncsi_rcv_rsp+0x16c/0x1d4)
[   42.905314] [<8060b454>] (ncsi_rcv_rsp) from [<804d86c8>] (__netif_receive_skb_core+0x3c8/0xb50)
[   42.914158] [<804d86c8>] (__netif_receive_skb_core) from [<804d96cc>] (__netif_receive_skb+0x20/0x7c)
[   42.923420] [<804d96cc>] (__netif_receive_skb) from [<804de4b0>] (netif_receive_skb_internal+0x78/0x6a4)
[   42.932931] [<804de4b0>] (netif_receive_skb_internal) from [<804df980>] (netif_receive_skb+0x78/0x158)
[   42.942292] [<804df980>] (netif_receive_skb) from [<8042f204>] (ftgmac100_poll+0x43c/0x4e8)
[   42.950855] [<8042f204>] (ftgmac100_poll) from [<804e094c>] (net_rx_action+0x278/0x4c4)
[   42.958918] [<804e094c>] (net_rx_action) from [<801016a8>] (__do_softirq+0xe0/0x4c4)
[   42.966716] [<801016a8>] (__do_softirq) from [<8011cd9c>] (do_softirq.part.4+0x50/0x78)
[   42.974756] [<8011cd9c>] (do_softirq.part.4) from [<8011cebc>] (__local_bh_enable_ip+0xf8/0x11c)
[   42.983579] [<8011cebc>] (__local_bh_enable_ip) from [<804dde08>] (__dev_queue_xmit+0x260/0x890)
[   42.992392] [<804dde08>] (__dev_queue_xmit) from [<804df1f0>] (dev_queue_xmit+0x1c/0x20)
[   43.000689] [<804df1f0>] (dev_queue_xmit) from [<806099c0>] (ncsi_xmit_cmd+0x1c0/0x244)
[   43.008763] [<806099c0>] (ncsi_xmit_cmd) from [<8060dc14>] (ncsi_dev_work+0x2e0/0x4c8)
[   43.016725] [<8060dc14>] (ncsi_dev_work) from [<80133dfc>] (process_one_work+0x214/0x6f8)
[   43.024940] [<80133dfc>] (process_one_work) from [<80134328>] (worker_thread+0x48/0x558)
[   43.033070] [<80134328>] (worker_thread) from [<8013ba80>] (kthread+0x130/0x174)
[   43.040506] [<8013ba80>] (kthread) from [<80102950>] (ret_from_fork+0x14/0x24)

Fixes: 062b3e1 ("net/ncsi: Refactor MAC, VLAN filters")
Signed-off-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
frank-w pushed a commit that referenced this pull request May 11, 2022
…fixes

WARNING: line over 80 characters
#65: FILE: mm/hugetlb.c:4469:
+	 * an active hugepage in pagecache. This goto expects the 2nd page fault,

total: 0 errors, 1 warnings, 48 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
      mechanically convert to the typical style using --fix or --fix-inplace.

./patches/mm-hugetlb-fix-a-typo-in-comment-manitained-maintained-v2.patch has style problems, please review.

NOTE: If any of the errors are false positives, please report
      them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Ethon Paul <ethp@qq.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
frank-w pushed a commit that referenced this pull request Nov 28, 2022
[ Upstream commit 230db82 ]

When a console stack dump is initiated with CONFIG_GCOV_PROFILE_ALL
enabled, show_trace_log_lvl() gets out of sync with the ORC unwinder,
causing the stack trace to show all text addresses as unreliable:

  # echo l > /proc/sysrq-trigger
  [  477.521031] sysrq: Show backtrace of all active CPUs
  [  477.523813] NMI backtrace for cpu 0
  [  477.524492] CPU: 0 PID: 1021 Comm: bash Not tainted 6.0.0 #65
  [  477.525295] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.0-1.fc36 04/01/2014
  [  477.526439] Call Trace:
  [  477.526854]  <TASK>
  [  477.527216]  ? dump_stack_lvl+0xc7/0x114
  [  477.527801]  ? dump_stack+0x13/0x1f
  [  477.528331]  ? nmi_cpu_backtrace.cold+0xb5/0x10d
  [  477.528998]  ? lapic_can_unplug_cpu+0xa0/0xa0
  [  477.529641]  ? nmi_trigger_cpumask_backtrace+0x16a/0x1f0
  [  477.530393]  ? arch_trigger_cpumask_backtrace+0x1d/0x30
  [  477.531136]  ? sysrq_handle_showallcpus+0x1b/0x30
  [  477.531818]  ? __handle_sysrq.cold+0x4e/0x1ae
  [  477.532451]  ? write_sysrq_trigger+0x63/0x80
  [  477.533080]  ? proc_reg_write+0x92/0x110
  [  477.533663]  ? vfs_write+0x174/0x530
  [  477.534265]  ? handle_mm_fault+0x16f/0x500
  [  477.534940]  ? ksys_write+0x7b/0x170
  [  477.535543]  ? __x64_sys_write+0x1d/0x30
  [  477.536191]  ? do_syscall_64+0x6b/0x100
  [  477.536809]  ? entry_SYSCALL_64_after_hwframe+0x63/0xcd
  [  477.537609]  </TASK>

This happens when the compiled code for show_stack() has a single word
on the stack, and doesn't use a tail call to show_stack_log_lvl().
(CONFIG_GCOV_PROFILE_ALL=y is the only known case of this.)  Then the
__unwind_start() skip logic hits an off-by-one bug and fails to unwind
all the way to the intended starting frame.

Fix it by reverting the following commit:

  f1d9a2a ("x86/unwind/orc: Don't skip the first frame for inactive tasks")

The original justification for that commit no longer exists.  That
original issue was later fixed in a different way, with the following
commit:

  f2ac57a ("x86/unwind/orc: Fix inactive tasks with stack pointer in %sp on GCC 10 compiled kernels")

Fixes: f1d9a2a ("x86/unwind/orc: Don't skip the first frame for inactive tasks")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
[jpoimboe: rewrite commit log]
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
frank-w pushed a commit that referenced this pull request Nov 28, 2022
[ Upstream commit 230db82 ]

When a console stack dump is initiated with CONFIG_GCOV_PROFILE_ALL
enabled, show_trace_log_lvl() gets out of sync with the ORC unwinder,
causing the stack trace to show all text addresses as unreliable:

  # echo l > /proc/sysrq-trigger
  [  477.521031] sysrq: Show backtrace of all active CPUs
  [  477.523813] NMI backtrace for cpu 0
  [  477.524492] CPU: 0 PID: 1021 Comm: bash Not tainted 6.0.0 #65
  [  477.525295] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.0-1.fc36 04/01/2014
  [  477.526439] Call Trace:
  [  477.526854]  <TASK>
  [  477.527216]  ? dump_stack_lvl+0xc7/0x114
  [  477.527801]  ? dump_stack+0x13/0x1f
  [  477.528331]  ? nmi_cpu_backtrace.cold+0xb5/0x10d
  [  477.528998]  ? lapic_can_unplug_cpu+0xa0/0xa0
  [  477.529641]  ? nmi_trigger_cpumask_backtrace+0x16a/0x1f0
  [  477.530393]  ? arch_trigger_cpumask_backtrace+0x1d/0x30
  [  477.531136]  ? sysrq_handle_showallcpus+0x1b/0x30
  [  477.531818]  ? __handle_sysrq.cold+0x4e/0x1ae
  [  477.532451]  ? write_sysrq_trigger+0x63/0x80
  [  477.533080]  ? proc_reg_write+0x92/0x110
  [  477.533663]  ? vfs_write+0x174/0x530
  [  477.534265]  ? handle_mm_fault+0x16f/0x500
  [  477.534940]  ? ksys_write+0x7b/0x170
  [  477.535543]  ? __x64_sys_write+0x1d/0x30
  [  477.536191]  ? do_syscall_64+0x6b/0x100
  [  477.536809]  ? entry_SYSCALL_64_after_hwframe+0x63/0xcd
  [  477.537609]  </TASK>

This happens when the compiled code for show_stack() has a single word
on the stack, and doesn't use a tail call to show_stack_log_lvl().
(CONFIG_GCOV_PROFILE_ALL=y is the only known case of this.)  Then the
__unwind_start() skip logic hits an off-by-one bug and fails to unwind
all the way to the intended starting frame.

Fix it by reverting the following commit:

  f1d9a2a ("x86/unwind/orc: Don't skip the first frame for inactive tasks")

The original justification for that commit no longer exists.  That
original issue was later fixed in a different way, with the following
commit:

  f2ac57a ("x86/unwind/orc: Fix inactive tasks with stack pointer in %sp on GCC 10 compiled kernels")

Fixes: f1d9a2a ("x86/unwind/orc: Don't skip the first frame for inactive tasks")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
[jpoimboe: rewrite commit log]
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
frank-w pushed a commit that referenced this pull request Nov 28, 2022
[ Upstream commit 230db82 ]

When a console stack dump is initiated with CONFIG_GCOV_PROFILE_ALL
enabled, show_trace_log_lvl() gets out of sync with the ORC unwinder,
causing the stack trace to show all text addresses as unreliable:

  # echo l > /proc/sysrq-trigger
  [  477.521031] sysrq: Show backtrace of all active CPUs
  [  477.523813] NMI backtrace for cpu 0
  [  477.524492] CPU: 0 PID: 1021 Comm: bash Not tainted 6.0.0 #65
  [  477.525295] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.0-1.fc36 04/01/2014
  [  477.526439] Call Trace:
  [  477.526854]  <TASK>
  [  477.527216]  ? dump_stack_lvl+0xc7/0x114
  [  477.527801]  ? dump_stack+0x13/0x1f
  [  477.528331]  ? nmi_cpu_backtrace.cold+0xb5/0x10d
  [  477.528998]  ? lapic_can_unplug_cpu+0xa0/0xa0
  [  477.529641]  ? nmi_trigger_cpumask_backtrace+0x16a/0x1f0
  [  477.530393]  ? arch_trigger_cpumask_backtrace+0x1d/0x30
  [  477.531136]  ? sysrq_handle_showallcpus+0x1b/0x30
  [  477.531818]  ? __handle_sysrq.cold+0x4e/0x1ae
  [  477.532451]  ? write_sysrq_trigger+0x63/0x80
  [  477.533080]  ? proc_reg_write+0x92/0x110
  [  477.533663]  ? vfs_write+0x174/0x530
  [  477.534265]  ? handle_mm_fault+0x16f/0x500
  [  477.534940]  ? ksys_write+0x7b/0x170
  [  477.535543]  ? __x64_sys_write+0x1d/0x30
  [  477.536191]  ? do_syscall_64+0x6b/0x100
  [  477.536809]  ? entry_SYSCALL_64_after_hwframe+0x63/0xcd
  [  477.537609]  </TASK>

This happens when the compiled code for show_stack() has a single word
on the stack, and doesn't use a tail call to show_stack_log_lvl().
(CONFIG_GCOV_PROFILE_ALL=y is the only known case of this.)  Then the
__unwind_start() skip logic hits an off-by-one bug and fails to unwind
all the way to the intended starting frame.

Fix it by reverting the following commit:

  f1d9a2a ("x86/unwind/orc: Don't skip the first frame for inactive tasks")

The original justification for that commit no longer exists.  That
original issue was later fixed in a different way, with the following
commit:

  f2ac57a ("x86/unwind/orc: Fix inactive tasks with stack pointer in %sp on GCC 10 compiled kernels")

Fixes: f1d9a2a ("x86/unwind/orc: Don't skip the first frame for inactive tasks")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
[jpoimboe: rewrite commit log]
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
frank-w pushed a commit that referenced this pull request Nov 28, 2022
[ Upstream commit 230db82 ]

When a console stack dump is initiated with CONFIG_GCOV_PROFILE_ALL
enabled, show_trace_log_lvl() gets out of sync with the ORC unwinder,
causing the stack trace to show all text addresses as unreliable:

  # echo l > /proc/sysrq-trigger
  [  477.521031] sysrq: Show backtrace of all active CPUs
  [  477.523813] NMI backtrace for cpu 0
  [  477.524492] CPU: 0 PID: 1021 Comm: bash Not tainted 6.0.0 #65
  [  477.525295] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.0-1.fc36 04/01/2014
  [  477.526439] Call Trace:
  [  477.526854]  <TASK>
  [  477.527216]  ? dump_stack_lvl+0xc7/0x114
  [  477.527801]  ? dump_stack+0x13/0x1f
  [  477.528331]  ? nmi_cpu_backtrace.cold+0xb5/0x10d
  [  477.528998]  ? lapic_can_unplug_cpu+0xa0/0xa0
  [  477.529641]  ? nmi_trigger_cpumask_backtrace+0x16a/0x1f0
  [  477.530393]  ? arch_trigger_cpumask_backtrace+0x1d/0x30
  [  477.531136]  ? sysrq_handle_showallcpus+0x1b/0x30
  [  477.531818]  ? __handle_sysrq.cold+0x4e/0x1ae
  [  477.532451]  ? write_sysrq_trigger+0x63/0x80
  [  477.533080]  ? proc_reg_write+0x92/0x110
  [  477.533663]  ? vfs_write+0x174/0x530
  [  477.534265]  ? handle_mm_fault+0x16f/0x500
  [  477.534940]  ? ksys_write+0x7b/0x170
  [  477.535543]  ? __x64_sys_write+0x1d/0x30
  [  477.536191]  ? do_syscall_64+0x6b/0x100
  [  477.536809]  ? entry_SYSCALL_64_after_hwframe+0x63/0xcd
  [  477.537609]  </TASK>

This happens when the compiled code for show_stack() has a single word
on the stack, and doesn't use a tail call to show_stack_log_lvl().
(CONFIG_GCOV_PROFILE_ALL=y is the only known case of this.)  Then the
__unwind_start() skip logic hits an off-by-one bug and fails to unwind
all the way to the intended starting frame.

Fix it by reverting the following commit:

  f1d9a2a ("x86/unwind/orc: Don't skip the first frame for inactive tasks")

The original justification for that commit no longer exists.  That
original issue was later fixed in a different way, with the following
commit:

  f2ac57a ("x86/unwind/orc: Fix inactive tasks with stack pointer in %sp on GCC 10 compiled kernels")

Fixes: f1d9a2a ("x86/unwind/orc: Don't skip the first frame for inactive tasks")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
[jpoimboe: rewrite commit log]
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
frank-w pushed a commit that referenced this pull request Nov 28, 2022
[ Upstream commit 230db82 ]

When a console stack dump is initiated with CONFIG_GCOV_PROFILE_ALL
enabled, show_trace_log_lvl() gets out of sync with the ORC unwinder,
causing the stack trace to show all text addresses as unreliable:

  # echo l > /proc/sysrq-trigger
  [  477.521031] sysrq: Show backtrace of all active CPUs
  [  477.523813] NMI backtrace for cpu 0
  [  477.524492] CPU: 0 PID: 1021 Comm: bash Not tainted 6.0.0 #65
  [  477.525295] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.0-1.fc36 04/01/2014
  [  477.526439] Call Trace:
  [  477.526854]  <TASK>
  [  477.527216]  ? dump_stack_lvl+0xc7/0x114
  [  477.527801]  ? dump_stack+0x13/0x1f
  [  477.528331]  ? nmi_cpu_backtrace.cold+0xb5/0x10d
  [  477.528998]  ? lapic_can_unplug_cpu+0xa0/0xa0
  [  477.529641]  ? nmi_trigger_cpumask_backtrace+0x16a/0x1f0
  [  477.530393]  ? arch_trigger_cpumask_backtrace+0x1d/0x30
  [  477.531136]  ? sysrq_handle_showallcpus+0x1b/0x30
  [  477.531818]  ? __handle_sysrq.cold+0x4e/0x1ae
  [  477.532451]  ? write_sysrq_trigger+0x63/0x80
  [  477.533080]  ? proc_reg_write+0x92/0x110
  [  477.533663]  ? vfs_write+0x174/0x530
  [  477.534265]  ? handle_mm_fault+0x16f/0x500
  [  477.534940]  ? ksys_write+0x7b/0x170
  [  477.535543]  ? __x64_sys_write+0x1d/0x30
  [  477.536191]  ? do_syscall_64+0x6b/0x100
  [  477.536809]  ? entry_SYSCALL_64_after_hwframe+0x63/0xcd
  [  477.537609]  </TASK>

This happens when the compiled code for show_stack() has a single word
on the stack, and doesn't use a tail call to show_stack_log_lvl().
(CONFIG_GCOV_PROFILE_ALL=y is the only known case of this.)  Then the
__unwind_start() skip logic hits an off-by-one bug and fails to unwind
all the way to the intended starting frame.

Fix it by reverting the following commit:

  f1d9a2a ("x86/unwind/orc: Don't skip the first frame for inactive tasks")

The original justification for that commit no longer exists.  That
original issue was later fixed in a different way, with the following
commit:

  f2ac57a ("x86/unwind/orc: Fix inactive tasks with stack pointer in %sp on GCC 10 compiled kernels")

Fixes: f1d9a2a ("x86/unwind/orc: Don't skip the first frame for inactive tasks")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
[jpoimboe: rewrite commit log]
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

Successfully merging this pull request may close these issues.

None yet

2 participants