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From: "H. Peter Anvin" <hpa@zytor.com>
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CC: Andrew Haley <aph@redhat.com>, Thomas Gleixner <tglx@linutronix.de>,         Ingo Molnar <mingo@elte.hu>, LKML <linux-kernel@vger.kernel.org>,         Andrew Morton <akpm@linux-foundation.org>,         Heiko Carstens <heiko.carstens@de.ibm.com>, feng.tang@intel.com,         Peter Zijlstra <peterz@infradead.org>,         Frederic Weisbecker <fweisbec@gmail.com>,         David Daney <ddaney@caviumnetworks.com>,         Richard Guenther <richard.guenther@gmail.com>, jakub@redhat.com,         gcc <gcc@gcc.gnu.org>, Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH][GIT PULL][v2.6.32] tracing/x86: Add check to detect   GCC messing with mcount prologue
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On 11/20/2009 11:46 AM, Steven Rostedt wrote:
> 
> Yes a gcc test suite will help new instances of gcc. But we need to
> worry about the instances of gcc that people have on their desktops now.
> This test case will catch the discrepancy between gcc and the function
> graph tracer. I'm not 100% convince that just adding -mtune=generic will
> help in all cases. If we miss another instance, then the function graph
> tracer may crash someone's kernel.
> 

Furthermore, for future gcc instances what we really want is the early
interception support anyway.

	-hpa