linux-kernel - Re: [PATCH 3/5] perf tools: Add GCC optimization to memory allocating functions

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <1291035249.2189.20.camel@cowboy>
Date:	Mon, 29 Nov 2010 09:54:09 -0300
From:	Davidlohr Bueso <dave@....org>
To:	Arnaldo Carvalho de Melo <acme@...hat.com>
Cc:	Ingo Molnar <mingo@...e.hu>, linux-kernel@...r.kernel.org,
	Paul Mackerras <paulus@...ba.org>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>
Subject: Re: [PATCH 3/5] perf tools: Add GCC optimization to memory
 allocating functions

On Fri, 2010-11-26 at 22:30 -0200, Arnaldo Carvalho de Melo wrote:
> Em Fri, Nov 26, 2010 at 07:47:19PM -0200, Arnaldo Carvalho de Melo escreveu:
> > From: Davidlohr Bueso <dave@....org>
> > 
> > We can benefit from the alloc_size attribute in xrealloc and zalloc.
> > 
> > Quoting from http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html:
> > 
> > "The alloc_size attribute is used to tell the compiler that the function return
> > value points to memory, where the size is given by one or two of the functions
> > parameters. GCC uses this information to improve the correctness of
> > __builtin_object_size."
> 
> Ingo, please don't pull this, it breaks the build with older GCCs...
> 

Sorry about that. This attribute was added for the 4.2 series in early
2007 (http://gcc.gnu.org/ml/gcc-patches/2007-04/msg01649.html)

> util/util.h:185: warning: ‘alloc_size’ attribute directive ignored
> util/util.h:190: warning: ‘alloc_size’ attribute directive ignored
> make: *** [/home/acme/git/build/perf/builtin-annotate.o] Error 1
> make: Leaving directory `/home/acme/git/linux-2.6-tip/tools/perf'
> [acme@...a linux-2.6-tip]$ gcc -v
> Using built-in specs.
> Target: x86_64-redhat-linux
> Configured with: ../configure --prefix=/usr --mandir=/usr/share/man
> --infodir=/usr/share/info --enable-shared --enable-threads=posix
> --enable-checking=release --with-system-zlib --enable-__cxa_atexit
> --disable-libunwind-exceptions --enable-libgcj-multifile
> --enable-languages=c,c++,objc,obj-c++,java,fortran,ada
> --enable-java-awt=gtk --disable-dssi --enable-plugin
> --with-java-home=/usr/lib/jvm/java-1.4.2-gcj-1.4.2.0/jre
> --with-cpu=generic --host=x86_64-redhat-linux
> Thread model: posix
> gcc version 4.1.2 20071124 (Red Hat 4.1.2-42)
> 
> I'll reorg this using compiler.h tricks probably, for now I'll just
> remove it from my perf/core branch.
> 
> - Arnaldo
> 


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/