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From: Keith Owens <kaos@sgi.com>
To: linux-kernel@vger.kernel.org
Subject: Re: [OT] backtrace 
In-reply-to: Your message of "Thu, 03 Oct 2002 09:31:06 +0100."
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Date: Thu, 03 Oct 2002 19:38:09 +1000
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On Thu, 03 Oct 2002 09:31:06 +0100, 
Padraig Brady <padraig.brady@corvil.com> wrote:
>Sorry to go off topic but this tip is just too useful IMHO.
>You can do the same in userspace with glibc. Details here:
>http://www.iol.ie/~padraiga/backtrace.c

info libc, /backtrace.

     Note that certain compiler optimisations may interfere with
     obtaining a valid backtrace.  Function inlining causes the inlined
     function to not have a stack frame; tail call optimisation
     replaces one stack frame with another; frame pointer elimination
     will stop `backtrace' from interpreting the stack contents
     correctly.

Most architectures compile with -fomit-frame-pointer (except for ARM
where RMK does it differently).  Neither gdb not glibc can cope with
kernel code built with -fomit-frame-pointer.  See the horrible
heuristics kdb has to apply to get any sort of backtrace on i386.

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