Re: [PATCH] context_tracking: Have ct_state() use preempt_disable_notrace()

[Josh Poimboeuf]

On Tue, Mar 21, 2023 at 08:45:24PM -0400, Steven Rostedt wrote:
> From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx>
> 
> One of my tests triggered:
> 
>  ------------[ cut here ]------------
>  WARNING: CPU: 0 PID: 1 at include/trace/events/preemptirq.h:51 trace_preempt_off+0x7c/0x80
>  Modules linked in:
>  CPU: 0 PID: 1 Comm: init Not tainted 6.3.0-rc3-test-00011-ge11b521a7b69-dirty #31
>  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.0-debian-1.16.0-5 04/01/2014
>  RIP: 0010:trace_preempt_off+0x7c/0x80
>  Code: 74 0f 48 8b 78 08 48 89 f2 48 89 de e8 5d f9 ff ff 65 ff 0d 6e d6 ce 68 75 a2 0f 1f 44 00 00 eb 9b e8 28 ea f3 ff 84 c0 75 a5 <0f> 0b eb a1 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f
>  RSP: 0000:ffffaf0880013f00 EFLAGS: 00010046
>  RAX: 0000000000000000 RBX: ffffffff97fafe59 RCX: 0000000000000001
>  RDX: 0000000000000000 RSI: ffffffff986f4b71 RDI: ffffffff986fa0dd
>  RBP: ffffffff97fafe59 R08: 0000000000000000 R09: 0000000000000000
>  R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
>  R13: 0000000000000014 R14: 0000000000000000 R15: 0000000000000000
>  FS:  0000000000000000(0000) GS:ffff8adf7bc00000(0000) knlGS:0000000000000000
>  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>  CR2: 00007f125de099c0 CR3: 000000010498a001 CR4: 0000000000170ef0
>  Call Trace:
>   <TASK>
>   irqentry_enter_from_user_mode+0x39/0x80
>   irqentry_enter+0x51/0x60
>   exc_page_fault+0x3d/0x200
>   asm_exc_page_fault+0x26/0x30

I think this was just fixed in -tip today:

  https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?id=f87d28673b71b35b248231a2086f9404afbb7f28

-- 
Josh