lkml.org 
[lkml]   [2021]   [Sep]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v2 0/6] wchan: Fix ORC support and leaky fallback
On Wed, Sep 29, 2021 at 03:02:12PM -0700, Kees Cook wrote:
> Hi,
>
> This attempts to solve the issues from the discussion here[1]. Specifically:
>
> 1) wchan leaking raw addresses since 152c432b128c (v5.12).
>
> patch 1 fixes this with a revert.
>
> 2) wchan has been broken under ORC, seen as a failure to stack walk
> resulting in _usually_ a 0 value, since ee9f8fce9964 (v4.14).
>
> patches 2-5 fixes this with Qi Zheng's new get_wchan() and changes to
> the /proc code to use the new helper suggested by Peter to do the stack
> walk only if the process can be kept blocked:
> https://lore.kernel.org/lkml/20210929194026.GA4323@worktop.programming.kicks-ass.net/
>
> Peter, can you take this via -tip?

It all looks sane to me. Thanks for cleaning up this mess.

- Should we use a similar sched wrapper for /proc/$pid/stack to make its
raciness go away?

- At the risk of triggering a much larger patch set, I suspect
get_wchan() can be made generic ;-) It's just a glorified wrapper
around stack_trace_save_tsk().

Regardless:

Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>

--
Josh

\
 
 \ /
  Last update: 2021-09-30 03:02    [W:0.090 / U:0.068 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site