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[PATCH] x86_64: Don't write out segments from vsyscall32 DSO if it is not mapped

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It's possible to get an invalid page fault in kernel mode when we try to
write out segments from vsyscall32 when dumping core for a 32bit process if
the vsyscall32 DSO is not mapped in its address space (which can happen if,
for example, ulimit -v 100 is run).

Signed-off-by: Suleiman Souhlal <suleiman@google.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Suleiman Souhlal 2006-08-30 19:37:20 +02:00 committed by Linus Torvalds
parent 01ebb77b31
commit ec0063b40a
1 changed files with 31 additions and 26 deletions
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57
arch/x86_64/ia32/ia32_binfmt.c
View file

@ -73,39 +73,44 @@ typedef elf_greg_t elf_gregset_t[ELF_NGREG];
* 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 (VSYSCALL32_EHDR->e_phnum)
#define ELF_CORE_EXTRA_PHDRS (find_vma(current->mm, VSYSCALL32_BASE) ? \
(VSYSCALL32_EHDR->e_phnum) : 0)
#define ELF_CORE_WRITE_EXTRA_PHDRS \
do { \
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; \
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)); \
} \
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 { \
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)); \
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)