x86, vdso: Error out if the vdso contains external references
authorH. Peter Anvin <hpa@linux.intel.com>
Fri, 18 Jun 2010 21:36:26 +0000 (14:36 -0700)
committerH. Peter Anvin <hpa@linux.intel.com>
Fri, 18 Jun 2010 21:46:21 +0000 (14:46 -0700)
commit05d0b0889ca9d033a960542af7f8a13b3ad4f630
treef77ab36957838f0a262ac6efab1201dd5b8f0593
parent7e27d6e778cd87b6f2415515d7127eba53fe5d02
x86, vdso: Error out if the vdso contains external references

The vdso is a piece of userspace code which is supposed to be fully
self-contained.  Any external (undefined) reference is an error, and
should be caught at compile time.  This was giving us trouble when
compiling with -Os on gcc 4.5.0, for example (failed inline).

The need to do a buildtime check was pointed out by Andi Kleen.

Reported-by: Andi Kleen <andi@firstfloor.org>
LKML-Reference: <tip-*@vger.kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
arch/x86/vdso/Makefile
arch/x86/vdso/checkundef.sh [new file with mode: 0755]