linux-kernel - Re: tools/lib/lk: redefinition of _FORTIFY

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID: <ghppwh4etj.fsf@mx10.gouders.net>
Date:	Thu, 23 May 2013 22:32:56 +0200
From:	Dirk Gouders <dirk@...ders.net>
To:	Borislav Petkov <bp@...e.de>
Cc:	Jiri Olsa <jolsa@...hat.com>, linux-kernel@...r.kernel.org
Subject: Re: tools/lib/lk: redefinition of _FORTIFY_SOURCE (gcc-4.7.2)

Hi Borislav,

Borislav Petkov <bp@...e.de> writes:

> Hi,
>
> On Wed, May 22, 2013 at 12:00:21PM +0200, Dirk Gouders wrote:
>> CFLAGS = -ggdb3 -Wall -Wextra -std=gnu99 -Werror -O6 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 $(EXTRA_WARNINGS) $(EXTRA_CFLAGS) -fPIC
>
> it seems someone else hit this already and fixed it too:
>
> commit d2f32479e5526a1ab3b4e43910fcb279871524ce
> Author: Marcin Slusarz <marcin.slusarz@...il.com>
> Date:   Sun Feb 17 16:03:36 2013 +0100
>
>     perf tools: check if -DFORTIFY_SOURCE=2 is allowed

I thought about this _FORTIFY_SOURCE test and how the above commit
could/should be adopted to lib/lk/Makefile, and I thought that if it
were true that recent versions of gcc define _FORTIFY_SOURCE by default,
that test could probably be modified and just check gcc's builtin macros to
find out if _FORTIFY_SOURCE has to be defined explicitely and I tried to
find out when gcc started to use _FORTIFY_SOURCE builtin definitions...

In short: all what I said in my initial post was tested with gcc
versions on gentoo machines and it is gentoo that patches gcc so that
_FORTIFY_SOURCE becomes a builtin definition.  Unfortunately I don't
have access to machines running other distributions and can only report
about gcc on gentoo, but even with this limited information I would say
it depends on the distribution in use if -D_FORTIFY_SOURCE=2 is needed
and not on the gcc version.

Sorry for the noise if you already noticed my fault, I felt I should
correct my initial misleading information.

Dirk
--
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/