Re: [PATCH] perf: x86: fix callgraphs of 32-bit processes on 64-bit kernels V4.

[Frederic Weisbecker <fweisbec@gmail.com>]

On Wed, Mar 17, 2010 at 12:07:16PM +0200, Török Edwin wrote:
> When profiling a 32-bit process on a 64-bit kernel, callgraph tracing
> stopped after the first function, because it has seen a garbage memory address
> (tried to interpret the frame pointer, and return address as a 64-bit pointer).
> 
> Fix this by using a struct stack_frame with 32-bit pointers when the TIF_IA32 flag is set.
> 
> Note that TIF_IA32 flag must be used, and not is_compat_task(), because the
> latter is only set when the 32-bit process is executing a syscall,
> which may not always be the case (when tracing page fault events for example).
> 
> Cc: "H. Peter Anvin" <hpa@zytor.com>
> Cc: Frederic Weisbecker <fweisbec@gmail.com>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: x86@kernel.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Török Edwin <edwintorok@gmail.com>


Queued, thanks!