lkml.org 
[lkml]   [2020]   [Jun]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH -tip v3 1/2] kcov: Make runtime functions noinstr-compatible
On Wed, Jun 17, 2020 at 05:19:59PM +0200, Marco Elver wrote:

> > Does GCC (8, as per the new KASAN thing) have that
> > __builtin_memcpy_inline() ?
>
> No, sadly it doesn't. Only Clang 11. :-/
>
> But using a call to __memcpy() somehow breaks with Clang+KCSAN. Yet,
> it's not the memcpy that BUGs, but once again check_preemption_disabled
> (which is noinstr!). Just adding calls anywhere here seems to results in
> unpredictable behaviour. Are we running out of stack space?

Very likely, bad_iret is running on that entry_stack you found, and as
you found, it is puny.

Andy wanted to make it a full page a while ago, so I suppose the
question is do we do that now?

\
 
 \ /
  Last update: 2020-06-17 17:56    [W:0.057 / U:0.344 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site