[PATCH] i386: Relocate VDSO ELF headers to match mapped location with COMPAT_VDSO
authorJeremy Fitzhardinge <jeremy@goop.org>
Wed, 2 May 2007 17:27:12 +0000 (19:27 +0200)
committerAndi Kleen <andi@basil.nowhere.org>
Wed, 2 May 2007 17:27:12 +0000 (19:27 +0200)
commitd4f7a2c18e59e0304a1c733589ce14fc02fec1bd
tree99c64275f7eb50925aad71a74ae083ececdbb795
parenta6c4e076ee4c1ea670e4faa55814e63dd08e3f29
[PATCH] i386: Relocate VDSO ELF headers to match mapped location with COMPAT_VDSO

Some versions of libc can't deal with a VDSO which doesn't have its
ELF headers matching its mapped address.  COMPAT_VDSO maps the VDSO at
a specific system-wide fixed address.  Previously this was all done at
build time, on the grounds that the fixed VDSO address is always at
the top of the address space.  However, a hypervisor may reserve some
of that address space, pushing the fixmap address down.

This patch does the adjustment dynamically at runtime, depending on
the runtime location of the VDSO fixmap.

[ Patch has been through several hands: Jan Beulich wrote the orignal
  version; Zach reworked it, and Jeremy converted it to relocate phdrs
  as well as sections. ]

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Zachary Amsden <zach@vmware.com>
Cc: "Jan Beulich" <JBeulich@novell.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Roland McGrath <roland@redhat.com>
arch/i386/kernel/entry.S
arch/i386/kernel/sysenter.c
arch/i386/mm/pgtable.c
include/asm-i386/elf.h
include/asm-i386/fixmap.h
include/linux/elf.h