[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>
This commit is contained in:
Jeremy Fitzhardinge 2007-05-02 19:27:12 +02:00 committed by Andi Kleen
parent a6c4e076ee
commit d4f7a2c18e
6 changed files with 178 additions and 43 deletions

View file

@ -83,6 +83,23 @@ typedef __s64 Elf64_Sxword;
#define DT_DEBUG 21
#define DT_TEXTREL 22
#define DT_JMPREL 23
#define DT_ENCODING 32
#define OLD_DT_LOOS 0x60000000
#define DT_LOOS 0x6000000d
#define DT_HIOS 0x6ffff000
#define DT_VALRNGLO 0x6ffffd00
#define DT_VALRNGHI 0x6ffffdff
#define DT_ADDRRNGLO 0x6ffffe00
#define DT_ADDRRNGHI 0x6ffffeff
#define DT_VERSYM 0x6ffffff0
#define DT_RELACOUNT 0x6ffffff9
#define DT_RELCOUNT 0x6ffffffa
#define DT_FLAGS_1 0x6ffffffb
#define DT_VERDEF 0x6ffffffc
#define DT_VERDEFNUM 0x6ffffffd
#define DT_VERNEED 0x6ffffffe
#define DT_VERNEEDNUM 0x6fffffff
#define OLD_DT_HIOS 0x6fffffff
#define DT_LOPROC 0x70000000
#define DT_HIPROC 0x7fffffff