[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>

1 files changed, 17 insertions, 0 deletions

diff --git a/include/linux/elf.h b/include/linux/elf.h
index 60713e6ea297..8b17ffe222c4 100644
--- a/include/linux/elf.h
+++ b/include/linux/elf.h
@@ -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