lkml.org 
[lkml]   [2020]   [Nov]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH AUTOSEL 4.19 18/21] kprobes: Tell lockdep about kprobe nesting
On Tue, Nov 10, 2020 at 03:44:58PM +0900, Masami Hiramatsu wrote:
>Hi,
>
>On Mon, 9 Nov 2020 22:55:38 -0500
>Sasha Levin <sashal@kernel.org> wrote:
>
>> From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
>>
>> [ Upstream commit 645f224e7ba2f4200bf163153d384ceb0de5462e ]
>>
>> Since the kprobe handlers have protection that prohibits other handlers from
>> executing in other contexts (like if an NMI comes in while processing a
>> kprobe, and executes the same kprobe, it will get fail with a "busy"
>> return). Lockdep is unaware of this protection. Use lockdep's nesting api to
>> differentiate between locks taken in INT3 context and other context to
>> suppress the false warnings.
>>
>> Link: https://lore.kernel.org/r/20201102160234.fa0ae70915ad9e2b21c08b85@kernel.org
>>
>
>This fixes a lockdep false positive warning comes from commit e03b4a084ea6
>("kprobes: Remove NMI context check"). Does anyone report that happen on the
>stable kernel?
>
>If not, you do not need this patch for stable kernels.

I'll drop it, thanks!

--
Thanks,
Sasha

\
 
 \ /
  Last update: 2020-11-15 00:00    [W:0.048 / U:0.140 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site