3.19.8-ckt21 -stable review patch. If anyone has any objections, please let me know.
---8<------------------------------------------------------------ From: Kees Cook <[email protected]> commit c6f5b001e65cdac592b65a08c5d2dd179cfba568 upstream. 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 <[email protected]> Acked-by: Martin Schwidefsky <[email protected]> Cc: Heiko Carstens <[email protected]> Reviewed-by: Ingo Molnar <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Kamal Mostafa <[email protected]> --- arch/s390/include/asm/elf.h | 8 +++++--- 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 c9df40b..2e63de8 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 a94504d..8c11536 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 -- 2.7.4
