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| author | Kees Cook <keescook@chromium.org> | 2015-04-15 00:48:04 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-04-15 01:49:05 +0200 |
| commit | c6f5b001e65cdac592b65a08c5d2dd179cfba568 (patch) | |
| tree | 3039e744e13eac169969882aed3226a8f6ce6186 /arch/s390 | |
| parent | mm: expose arch_mmap_rnd when available (diff) | |
| download | linux-c6f5b001e65cdac592b65a08c5d2dd179cfba568.tar.xz linux-c6f5b001e65cdac592b65a08c5d2dd179cfba568.zip | |
s390: redefine randomize_et_dyn for ELF_ET_DYN_BASE
In preparation for moving ET_DYN randomization into the ELF loader (which
requires a static ELF_ET_DYN_BASE), this redefines s390's existing ET_DYN
randomization in a call to arch_mmap_rnd(). This refactoring results in
the same ET_DYN randomization on s390.
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/include/asm/elf.h | 8 | ||||
| -rw-r--r-- | arch/s390/mm/mmap.c | 11 |
2 files changed, 7 insertions, 12 deletions
diff --git a/arch/s390/include/asm/elf.h b/arch/s390/include/asm/elf.h index c9c875d9ed31..f8db4781a4c2 100644 --- a/arch/s390/include/asm/elf.h +++ b/arch/s390/include/asm/elf.h @@ -161,10 +161,12 @@ extern unsigned int vdso_enabled; /* This is the location that an ET_DYN program is loaded if exec'ed. Typical use of this is to invoke "./ld.so someprog" to test out a new version of the loader. We need to make sure that it is out of the way of the program - that it will "exec", and that there is sufficient room for the brk. */ - + that it will "exec", and that there is sufficient room for the brk. 64-bit + tasks are aligned to 4GB. */ extern unsigned long randomize_et_dyn(void); -#define ELF_ET_DYN_BASE randomize_et_dyn() +#define ELF_ET_DYN_BASE (randomize_et_dyn() + (is_32bit_task() ? \ + (STACK_TOP / 3 * 2) : \ + (STACK_TOP / 3 * 2) & ~((1UL << 32) - 1))) /* This yields a mask that user programs can use to figure out what instruction set this CPU supports. */ diff --git a/arch/s390/mm/mmap.c b/arch/s390/mm/mmap.c index a94504d99c47..8c11536f972d 100644 --- a/arch/s390/mm/mmap.c +++ b/arch/s390/mm/mmap.c @@ -179,17 +179,10 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, unsigned long randomize_et_dyn(void) { - unsigned long base; - - base = STACK_TOP / 3 * 2; - if (!is_32bit_task()) - /* Align to 4GB */ - base &= ~((1UL << 32) - 1); - if (current->flags & PF_RANDOMIZE) - base += arch_mmap_rnd(); + return arch_mmap_rnd(); - return base; + return 0UL; } #ifndef CONFIG_64BIT |