Re: [tip:tracing/core] x86/tracing: comment need for atomic nop

From: Steven Rostedt
Date: Sat Sep 12 2009 - 14:05:29 EST


On Sat, 2009-09-12 at 09:45 -0400, Mathieu Desnoyers wrote:
> * tip-bot for Steven Rostedt (srostedt@xxxxxxxxxx) wrote:
> > Commit-ID: fc06b8520b3bf9aaeb2e27debe6719c215bd4916
> > Gitweb: http://git.kernel.org/tip/fc06b8520b3bf9aaeb2e27debe6719c215bd4916
> > Author: Steven Rostedt <srostedt@xxxxxxxxxx>
> > AuthorDate: Thu, 10 Sep 2009 17:22:44 -0400
> > Committer: Steven Rostedt <rostedt@xxxxxxxxxxx>
> > CommitDate: Thu, 10 Sep 2009 17:22:44 -0400
> >
> > x86/tracing: comment need for atomic nop
> >
> > The dynamic function tracer relys on the macro P6_NOP5 always being
> > an atomic NOP. If for some reason it is changed to be two operations
> > (like a nop2 nop3) it can faults within the kernel when the function
> > tracer modifies the code.
> >
> > This patch adds a comment to note that the P6_NOPs are expected to
> > be atomic. This will hopefully prevent anyone from changing that.
> >
> > Reported-by: Mathieu Desnoyer <mathieu.desnoyers@xxxxxxxxxx>
>
> With an added "s" to my last name, that will be good.

Oops, sorry. I seem to always do that to your name. I was too busy
concentrating in getting your email correct (wrote the commit on a
different box than my email client) that I didn't notice your name was
wrong.

-- Steve

>
> Thanks !
>
> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxx>
>
> > Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>


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