From 7f3646aa16f496201e045183402c6614fa27b0c7 Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Wed, 30 Jan 2008 13:30:41 +0100 Subject: [PATCH] x86 vDSO: use vdso-syms.lds 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 Cc: Andrew Morton Cc: Linus Torvalds Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- 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..d2ec1704 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 #include #include -#include "voffset.h" +#include -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 */ -- 2.7.4