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Commit e03f0ca1 authored by Roland McGrath's avatar Roland McGrath Committed by Linus Torvalds
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[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: default avatarRoland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent f47aef55

arch/x86_64/ia32/ia32_binfmt.c

+0 −49
Original line number Original line Diff line number Diff line
@@ -64,55 +64,6 @@ typedef unsigned int elf_greg_t; 
#define ELF_NGREG (sizeof (struct user_regs_struct32) / sizeof(elf_greg_t))

#define ELF_NGREG (sizeof (struct user_regs_struct32) / sizeof(elf_greg_t))

typedef elf_greg_t elf_gregset_t[ELF_NGREG];

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

struct elf_siginfo

{

{

	int	si_signo;			/* signal number */

	int	si_signo;			/* signal number */

arch/x86_64/ia32/syscall32.c

+7 −0
Original line number Original line Diff line number Diff line
@@ -59,6 +59,13 @@ int syscall32_setup_pages(struct linux_binprm *bprm, int exstack) 
	vma->vm_end = VSYSCALL32_END;

	vma->vm_end = VSYSCALL32_END;

	/* MAYWRITE to allow gdb to COW and set breakpoints */

	/* MAYWRITE to allow gdb to COW and set breakpoints */

	vma->vm_flags = VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYEXEC|VM_MAYWRITE;

	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_flags |= mm->def_flags;

	vma->vm_page_prot = protection_map[vma->vm_flags & 7];

	vma->vm_page_prot = protection_map[vma->vm_flags & 7];

	vma->vm_ops = &syscall32_vm_ops;

	vma->vm_ops = &syscall32_vm_ops;