This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
Re: [PATCH] Ensure DSO_FILENAME does not dereference NULL.
- From: pinskia at gmail dot com
- To: Marcus Shawcroft <marcus dot shawcroft at linaro dot org>
- Cc: GNU C Library <libc-alpha at sourceware dot org>
- Date: Tue, 12 Nov 2013 10:27:48 -0800
- Subject: Re: [PATCH] Ensure DSO_FILENAME does not dereference NULL.
- Authentication-results: sourceware.org; auth=none
- References: <CABXK9ndMvnpRArWGU4-JWgiePLOXNs74AuK9C6dm0J1Gyu+k_A at mail dot gmail dot com>
> On Nov 12, 2013, at 7:24 AM, Marcus Shawcroft <marcus.shawcroft@linaro.org> wrote:
>
> The AArch64 and ARM glibc build is currently broken for trunk gcc.
> Both builds fail with link errors for the multiple definition of
> _dl_addr_inside_object.
>
> This is caused by the "Isolate erroneous paths optimization" patch
> recently added to gcc here:
>
> http://gcc.gnu.org/ml/gcc-patches/2013-10/msg02648.html
>
> One effect of this patch is to replace unreachable paths with a call to abort().
Hmm, it calls __builtin_trap shouldn't GCC back end for both arm and aarch64 support that directly instead?
Thanks,
Andrew
>
> There is code in _dl_lookup_symbol_x() which may pass NULL to
> DSO_FILENAME(). This macro always dereferences the filename. The
> isolate erroneous paths cod in gcc inserts an abort() in place of the
> ill defined code. The linker subsequently pulls in a bunch of code
> from libpic.a, including the alternative definition of
> _dl_addr_inside_object.
>
> The convention elsewhere appears to be to pass "" rather than NULL.
> This patch seems obvious to me, I'll commit it tomorrow unless anyone
> objects.
>
> * elf/dl-lookup.c (_dl_lookup_symbol_x): Pass "" instead of NULL to
> DSO_FILENAME().
>
> Cheers
> /Marcus
> <0002-DSO_FILENAME-expects-rather-than-NULL.txt>