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Date: Fri, 24 Oct 2014 12:30:30 +0200
From: Peter Zijlstra <peterz@infradead.org>
Subject: Re: [RFC PATCH] UBSan: run-time undefined behavior sanity checker
Message-ID: <20141024103030.GH12706@worktop.programming.kicks-ass.net>
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To: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Andrew Morton <akpm@linux-foundation.org>, Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>, Michal Marek <mmarek@suse.cz>, Sasha Levin <sasha.levin@oracle.com>, x86@kernel.org, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, Theodore Ts'o <tytso@mit.edu>, Andreas Dilger <adilger.kernel@dilger.ca>, Dmitry Vyukov <dvyukov@google.com>, Konstantin Khlebnikov <koct9i@gmail.com>

On Tue, Oct 21, 2014 at 02:09:14PM +0400, Andrey Ryabinin wrote:
> On 10/21/2014 01:47 PM, Peter Zijlstra wrote:
> > On Mon, Oct 20, 2014 at 02:54:59PM +0400, Andrey Ryabinin wrote:
> >>
> >> UBSan uses compile-time instrumentation to catch undefined behavior (UB).
> >> Compiler inserts code that perform certain kinds of
> >> checks before operations that could cause UB.
> >> If check fails (i.e. UB detected) __ubsan_handle_* function called.
> >> to print error message.
> >>
> >> So the most of the work is done by compiler.
> >> This patch just implements ubsan handlers printing errors.
> >>
> >> GCC supports this since 4.9, however upcoming GCC 5.0 has
> >> more checkers implemented.
> > 
> > It might be useful if you've got a link to the relevant GCC
> > documentation of this new shiny stuf.
> > 
> 
> Documentation is very brief (look for fsanitize=undefined): https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html
> GCC 4.9.1 doc: https://gcc.gnu.org/onlinedocs/gcc-4.9.1/gcc/Debugging-Options.html
> 
> And there is an article which might be interesting: http://developerblog.redhat.com/2014/10/16/gcc-undefined-behavior-sanitizer-ubsan/

Thanks, please consider including these in the changelog of future
postings of this patch set.