]> nv-tegra.nvidia Code Review - linux-2.6.git/commit
[PATCH] uml: host VDSO fix
authorJeff Dike <jdike@addtoit.com>
Thu, 1 Mar 2007 04:13:31 +0000 (20:13 -0800)
committerLinus Torvalds <torvalds@woody.linux-foundation.org>
Thu, 1 Mar 2007 22:53:38 +0000 (14:53 -0800)
commit14251809b1921b1216568700f1be2f91a1cbb5c7
tree7162d7623138be81cc733968bf69d0511011d21b
parentcf2775f175128fc9fd7ffb88981e068d27bc85db
[PATCH] uml: host VDSO fix

This fixes a problem seen by a number of people running UML on newer host
kernels.  init would hang with an infinite segfault loop.

It turns out that the host kernel was providing a AT_SYSINFO_EHDR of
0xffffe000, which faked UML into believing that the host VDSO page could be
reused.  However, AT_SYSINFO pointed into the middle of the address space, and
was unmapped as a result.  Because UML was providing AT_SYSINFO_EHDR and
AT_SYSINFO to its own processes, these would branch to nowhere when trying to
use the VDSO.

The fix is to also check the location of AT_SYSINFO when deciding whether to
use the host's VDSO.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arch/um/os-Linux/elf_aux.c