This patch changes the kernel's references to addresses in the vDSO image
to be based on the symbols defined by vdso-syms.lds instead of the old
vdso-syms.o symbols. This is all wrapped up in a macro defined by the new
asm-x86/vdso.h header; that's the only place in the kernel source that has
to know the details of the scheme for getting vDSO symbol values.
Signed-off-by: Roland McGrath <roland@redhat.com>
---
arch/x86/vdso/Makefile | 3 +--
arch/x86/vdso/vdso-start.S | 2 --
arch/x86/vdso/vma.c | 18 +++++++-----------
include/asm-x86/vdso.h | 14 ++++++++++++++
4 files changed, 22 insertions(+), 15 deletions(-)
delete mode 100644 arch/x86/vdso/vdso-start.S
create mode 100644 include/asm-x86/vdso.h
diff --git a/arch/x86/vdso/Makefile b/arch/x86/vdso/Makefile
index d8200ad..d2ec170 100644
--- a/arch/x86/vdso/Makefile
+++ b/arch/x86/vdso/Makefile
@@ -3,8 +3,7 @@
#
# files to link into the vdso
-# vdso-start.o has to be first
-vobjs-y := vdso-start.o vdso-note.o vclock_gettime.o vgetcpu.o vvar.o
+vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o vvar.o
# files to link into kernel
obj-y := vma.o vdso.o vdso-syms.o
diff --git a/arch/x86/vdso/vdso-start.S b/arch/x86/vdso/vdso-start.S
deleted file mode 100644
index 2dc2cdb..0000000
--- a/arch/x86/vdso/vdso-start.S
+++ /dev/null
@@ -1,2 +0,0 @@
- .globl vdso_kernel_start
-vdso_kernel_start:
diff --git a/arch/x86/vdso/vma.c b/arch/x86/vdso/vma.c
index ff9333e..3fdd514 100644
--- a/arch/x86/vdso/vma.c
+++ b/arch/x86/vdso/vma.c
@@ -11,23 +11,20 @@
#include <asm/vsyscall.h>
#include <asm/vgtod.h>
#include <asm/proto.h>
-#include "voffset.h"
+#include <asm/vdso.h>
-int vdso_enabled = 1;
-
-#define VEXTERN(x) extern typeof(__ ## x) *vdso_ ## x;
-#include "vextern.h"
+#include "vextern.h" /* Just for VMAGIC. */
#undef VEXTERN
-extern char vdso_kernel_start[], vdso_start[], vdso_end[];
+int vdso_enabled = 1;
+
+extern char vdso_start[], vdso_end[];
extern unsigned short vdso_sync_cpuid;
struct page **vdso_pages;
-static inline void *var_ref(void *vbase, char *var, char *name)
+static inline void *var_ref(void *p, char *name)
{
- unsigned offset = var - &vdso_kernel_start[0] + VDSO_TEXT_OFFSET;
- void *p = vbase + offset;
if (*(void **)p != (void *)VMAGIC) {
printk("VDSO: variable %s broken\n", name);
vdso_enabled = 0;
@@ -62,9 +59,8 @@ static int __init init_vdso_vars(void)
vdso_enabled = 0;
}
-#define V(x) *(typeof(x) *) var_ref(vbase, (char *)RELOC_HIDE(&x, 0), #x)
#define VEXTERN(x) \
- V(vdso_ ## x) = &__ ## x;
+ *(typeof(__ ## x) **) var_ref(VDSO64_SYMBOL(vbase, x), #x) = &__ ## x;
#include "vextern.h"
#undef VEXTERN
return 0;
diff --git a/include/asm-x86/vdso.h b/include/asm-x86/vdso.h
new file mode 100644
index 0000000..9379ec0
--- /dev/null
+++ b/include/asm-x86/vdso.h
@@ -0,0 +1,14 @@
+#ifndef _ASM_X86_VDSO_H
+#define _ASM_X86_VDSO_H 1
+
+extern const char VDSO64_PRELINK[];
+
+/*
+ * Given a pointer to the vDSO image, find the pointer to VDSO64_name
+ * as that symbol is defined in the vDSO sources or linker script.
+ */
+#define VDSO64_SYMBOL(base, name) ({ \
+ extern const char VDSO64_##name[]; \
+ (void *) (VDSO64_##name - VDSO64_PRELINK + (unsigned long) (base)); })
+
+#endif /* asm-x86/vdso.h */
-
