From e03f0ca11645ce69a4defcd4f60a5cb2d5e30507 Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Fri, 26 Jan 2007 00:56:50 -0800 Subject: [PATCH] [PATCH] x86_64 ia32 vDSO: use VM_ALWAYSDUMP This patch fixes ia32 core dumps on x86_64 to include just one phdr for the vDSO vma. Currently it writes a confused format with two phdrs for the address, one without contents and one with. This patch removes the special-case core writing macros for the ia32 vDSO. Instead, it uses VM_ALWAYSDUMP in the vma. This changes core dumps so they no longer include the non-PT_LOAD phdrs from the vDSO, consistent with fixed native i386 core dumps. Signed-off-by: Roland McGrath Cc: Ingo Molnar Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86_64/ia32/ia32_binfmt.c | 49 ---------------------------------- arch/x86_64/ia32/syscall32.c | 7 +++++ 2 files changed, 7 insertions(+), 49 deletions(-) diff --git a/arch/x86_64/ia32/ia32_binfmt.c b/arch/x86_64/ia32/ia32_binfmt.c index 543ef4f405e9..5ce0bd486bbf 100644 --- a/arch/x86_64/ia32/ia32_binfmt.c +++ b/arch/x86_64/ia32/ia32_binfmt.c @@ -64,55 +64,6 @@ typedef unsigned int elf_greg_t; #define ELF_NGREG (sizeof (struct user_regs_struct32) / sizeof(elf_greg_t)) typedef elf_greg_t elf_gregset_t[ELF_NGREG]; -/* - * These macros parameterize elf_core_dump in fs/binfmt_elf.c to write out - * extra segments containing the vsyscall DSO contents. Dumping its - * contents makes post-mortem fully interpretable later without matching up - * the same kernel and hardware config to see what PC values meant. - * Dumping its extra ELF program headers includes all the other information - * a debugger needs to easily find how the vsyscall DSO was being used. - */ -#define ELF_CORE_EXTRA_PHDRS (find_vma(current->mm, VSYSCALL32_BASE) ? \ - (VSYSCALL32_EHDR->e_phnum) : 0) -#define ELF_CORE_WRITE_EXTRA_PHDRS \ -do { \ - if (find_vma(current->mm, VSYSCALL32_BASE)) { \ - const struct elf32_phdr *const vsyscall_phdrs = \ - (const struct elf32_phdr *) (VSYSCALL32_BASE \ - + VSYSCALL32_EHDR->e_phoff);\ - int i; \ - Elf32_Off ofs = 0; \ - for (i = 0; i < VSYSCALL32_EHDR->e_phnum; ++i) { \ - struct elf32_phdr phdr = vsyscall_phdrs[i]; \ - if (phdr.p_type == PT_LOAD) { \ - BUG_ON(ofs != 0); \ - ofs = phdr.p_offset = offset; \ - phdr.p_memsz = PAGE_ALIGN(phdr.p_memsz); \ - phdr.p_filesz = phdr.p_memsz; \ - offset += phdr.p_filesz; \ - } \ - else \ - phdr.p_offset += ofs; \ - phdr.p_paddr = 0; /* match other core phdrs */ \ - DUMP_WRITE(&phdr, sizeof(phdr)); \ - } \ - } \ -} while (0) -#define ELF_CORE_WRITE_EXTRA_DATA \ -do { \ - if (find_vma(current->mm, VSYSCALL32_BASE)) { \ - const struct elf32_phdr *const vsyscall_phdrs = \ - (const struct elf32_phdr *) (VSYSCALL32_BASE \ - + VSYSCALL32_EHDR->e_phoff); \ - int i; \ - for (i = 0; i < VSYSCALL32_EHDR->e_phnum; ++i) { \ - if (vsyscall_phdrs[i].p_type == PT_LOAD) \ - DUMP_WRITE((void *) (u64) vsyscall_phdrs[i].p_vaddr,\ - PAGE_ALIGN(vsyscall_phdrs[i].p_memsz)); \ - } \ - } \ -} while (0) - struct elf_siginfo { int si_signo; /* signal number */ diff --git a/arch/x86_64/ia32/syscall32.c b/arch/x86_64/ia32/syscall32.c index 3e5ed20cba45..3ac935535e20 100644 --- a/arch/x86_64/ia32/syscall32.c +++ b/arch/x86_64/ia32/syscall32.c @@ -59,6 +59,13 @@ int syscall32_setup_pages(struct linux_binprm *bprm, int exstack) vma->vm_end = VSYSCALL32_END; /* MAYWRITE to allow gdb to COW and set breakpoints */ vma->vm_flags = VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYEXEC|VM_MAYWRITE; + /* + * Make sure the vDSO gets into every core dump. + * Dumping its contents makes post-mortem fully interpretable later + * without matching up the same kernel and hardware config to see + * what PC values meant. + */ + vma->vm_flags |= VM_ALWAYSDUMP; vma->vm_flags |= mm->def_flags; vma->vm_page_prot = protection_map[vma->vm_flags & 7]; vma->vm_ops = &syscall32_vm_ops; -- 2.20.1