From d4f7a2c18e59e0304a1c733589ce14fc02fec1bd Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Wed, 2 May 2007 19:27:12 +0200 Subject: [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 Signed-off-by: Andi Kleen Cc: Zachary Amsden Cc: "Jan Beulich" Cc: Eric W. Biederman Cc: Andi Kleen Cc: Ingo Molnar Cc: Roland McGrath --- include/asm-i386/elf.h | 28 ++++++++++------------------ include/asm-i386/fixmap.h | 8 ++------ 2 files changed, 12 insertions(+), 24 deletions(-) (limited to 'include/asm-i386') diff --git a/include/asm-i386/elf.h b/include/asm-i386/elf.h index 952b3ee3c9b..d304ab4161f 100644 --- a/include/asm-i386/elf.h +++ b/include/asm-i386/elf.h @@ -133,39 +133,31 @@ extern int dump_task_extended_fpu (struct task_struct *, struct user_fxsr_struct #define ELF_CORE_COPY_XFPREGS(tsk, elf_xfpregs) dump_task_extended_fpu(tsk, elf_xfpregs) #define VDSO_HIGH_BASE (__fix_to_virt(FIX_VDSO)) -#define VDSO_BASE ((unsigned long)current->mm->context.vdso) - -#ifdef CONFIG_COMPAT_VDSO -# define VDSO_COMPAT_BASE VDSO_HIGH_BASE -# define VDSO_PRELINK VDSO_HIGH_BASE -#else -# define VDSO_COMPAT_BASE VDSO_BASE -# define VDSO_PRELINK 0 -#endif +#define VDSO_CURRENT_BASE ((unsigned long)current->mm->context.vdso) +#define VDSO_PRELINK 0 #define VDSO_SYM(x) \ - (VDSO_COMPAT_BASE + (unsigned long)(x) - VDSO_PRELINK) + (VDSO_CURRENT_BASE + (unsigned long)(x) - VDSO_PRELINK) #define VDSO_HIGH_EHDR ((const struct elfhdr *) VDSO_HIGH_BASE) -#define VDSO_EHDR ((const struct elfhdr *) VDSO_COMPAT_BASE) +#define VDSO_EHDR ((const struct elfhdr *) VDSO_CURRENT_BASE) extern void __kernel_vsyscall; #define VDSO_ENTRY VDSO_SYM(&__kernel_vsyscall) -#ifndef CONFIG_COMPAT_VDSO -#define ARCH_HAS_SETUP_ADDITIONAL_PAGES struct linux_binprm; + +#define ARCH_HAS_SETUP_ADDITIONAL_PAGES extern int arch_setup_additional_pages(struct linux_binprm *bprm, int executable_stack); -#endif extern unsigned int vdso_enabled; -#define ARCH_DLINFO \ -do if (vdso_enabled) { \ - NEW_AUX_ENT(AT_SYSINFO, VDSO_ENTRY); \ - NEW_AUX_ENT(AT_SYSINFO_EHDR, VDSO_COMPAT_BASE); \ +#define ARCH_DLINFO \ +do if (vdso_enabled) { \ + NEW_AUX_ENT(AT_SYSINFO, VDSO_ENTRY); \ + NEW_AUX_ENT(AT_SYSINFO_EHDR, VDSO_CURRENT_BASE); \ } while (0) #endif diff --git a/include/asm-i386/fixmap.h b/include/asm-i386/fixmap.h index 3e9f610c35d..e5651b2a585 100644 --- a/include/asm-i386/fixmap.h +++ b/include/asm-i386/fixmap.h @@ -19,13 +19,9 @@ * Leave one empty page between vmalloc'ed areas and * the start of the fixmap. */ -#ifndef CONFIG_COMPAT_VDSO 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 +#define FIXADDR_USER_START __fix_to_virt(FIX_VDSO) +#define FIXADDR_USER_END __fix_to_virt(FIX_VDSO - 1) #ifndef __ASSEMBLY__ #include -- cgit v1.2.3