[PATCH] Fix CONFIG_COMPAT_VDSO

I wouldn't mind if CONFIG_COMPAT_VDSO went away entirely.  But if it's there,
it should work properly.  Currently it's quite haphazard: both real vma and
fixmap are mapped, both are put in the two different AT_* slots, sysenter
returns to the vma address rather than the fixmap address, and core dumps yet
are another story.

This patch makes CONFIG_COMPAT_VDSO disable the real vma and use the fixmap
area consistently.  This makes it actually compatible with what the old vdso
implementation did.

Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/asm-i386/fixmap.h b/include/asm-i386/fixmap.h
index 02428cb36621..3e9f610c35df 100644
--- a/include/asm-i386/fixmap.h
+++ b/include/asm-i386/fixmap.h
@@ -23,6 +23,8 @@
 extern unsigned long __FIXADDR_TOP;
 #else
 #define __FIXADDR_TOP  0xfffff000
+#define FIXADDR_USER_START      __fix_to_virt(FIX_VDSO)
+#define FIXADDR_USER_END        __fix_to_virt(FIX_VDSO - 1)
 #endif
 
 #ifndef __ASSEMBLY__