Re: [PATCH] perf: x86: fix callgraphs of 32-bit processes on64-bit kernels V4.

From: Frederic Weisbecker
Date: Tue Mar 30 2010 - 20:07:58 EST


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@xxxxxxxxx>
> Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
> Cc: Paul Mackerras <paulus@xxxxxxxxx>
> Cc: x86@xxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Signed-off-by: Török Edwin <edwintorok@xxxxxxxxx>


Queued, thanks!

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