Merge branch 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86-64, vdso: Do not allocate memory for the vDSO
  clocksource: Change __ARCH_HAS_CLOCKSOURCE_DATA to a CONFIG option
  x86, vdso: Drop now wrong comment
  Document the vDSO and add a reference parser
  ia64: Replace clocksource.fsys_mmio with generic arch data
  x86-64: Move vread_tsc and vread_hpet into the vDSO
  clocksource: Replace vread with generic arch data
  x86-64: Add --no-undefined to vDSO build
  x86-64: Allow alternative patching in the vDSO
  x86: Make alternative instruction pointers relative
  x86-64: Improve vsyscall emulation CS and RIP handling
  x86-64: Emulate legacy vsyscalls
  x86-64: Fill unused parts of the vsyscall page with 0xcc
  x86-64: Remove vsyscall number 3 (venosys)
  x86-64: Map the HPET NX
  x86-64: Remove kernel.vsyscall64 sysctl
  x86-64: Give vvars their own page
  x86-64: Document some of entry_64.S
  x86-64: Fix alignment of jiffies variable

1 files changed, 11 insertions, 13 deletions

diff --git a/arch/x86/include/asm/vvar.h b/arch/x86/include/asm/vvar.h
index 341b3559452..de656ac2af4 100644
--- a/arch/x86/include/asm/vvar.h
+++ b/arch/x86/include/asm/vvar.h
@@ -10,15 +10,14 @@
  * In normal kernel code, they are used like any other variable.
  * In user code, they are accessed through the VVAR macro.
  *
- * Each of these variables lives in the vsyscall page, and each
- * one needs a unique offset within the little piece of the page
- * reserved for vvars.  Specify that offset in DECLARE_VVAR.
- * (There are 896 bytes available.  If you mess up, the linker will
- * catch it.)
+ * These variables live in a page of kernel data that has an extra RO
+ * mapping for userspace.  Each variable needs a unique offset within
+ * that page; specify that offset with the DECLARE_VVAR macro.  (If
+ * you mess up, the linker will catch it.)
  */
 
-/* Offset of vars within vsyscall page */
-#define VSYSCALL_VARS_OFFSET (3072 + 128)
+/* Base address of vvars.  This is not ABI. */
+#define VVAR_ADDRESS (-10*1024*1024 - 4096)
 
 #if defined(__VVAR_KERNEL_LDS)
 
@@ -26,17 +25,17 @@
  * right place.
  */
 #define DECLARE_VVAR(offset, type, name) \
-	EMIT_VVAR(name, VSYSCALL_VARS_OFFSET + offset)
+	EMIT_VVAR(name, offset)
 
 #else
 
 #define DECLARE_VVAR(offset, type, name)				\
 	static type const * const vvaraddr_ ## name =			\
-		(void *)(VSYSCALL_START + VSYSCALL_VARS_OFFSET + (offset));
+		(void *)(VVAR_ADDRESS + (offset));
 
 #define DEFINE_VVAR(type, name)						\
-	type __vvar_ ## name						\
-	__attribute__((section(".vsyscall_var_" #name), aligned(16)))
+	type name							\
+	__attribute__((section(".vvar_" #name), aligned(16)))
 
 #define VVAR(name) (*vvaraddr_ ## name)
 
@@ -45,8 +44,7 @@
 /* DECLARE_VVAR(offset, type, name) */
 
 DECLARE_VVAR(0, volatile unsigned long, jiffies)
-DECLARE_VVAR(8, int, vgetcpu_mode)
+DECLARE_VVAR(16, int, vgetcpu_mode)
 DECLARE_VVAR(128, struct vsyscall_gtod_data, vsyscall_gtod_data)
 
 #undef DECLARE_VVAR
-#undef VSYSCALL_VARS_OFFSET