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author | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2013-11-14 17:38:05 -0800 |
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committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2013-11-14 17:38:05 -0800 |
commit | 42249094f79422fbf5ed4b54eeb48ff096809b8f (patch) | |
tree | 91e6850c8c7e8cc284cf8bb6363f8662f84011f4 /arch/tile/mm/mmap.c | |
parent | 936816161978ca716a56c5e553c68f25972b1e3a (diff) | |
parent | 2c027b7c48a888ab173ba45babb4525e278375d9 (diff) |
Merge branch 'next' into for-linus
Merge first round of changes for 3.13 merge window.
Diffstat (limited to 'arch/tile/mm/mmap.c')
-rw-r--r-- | arch/tile/mm/mmap.c | 26 |
1 files changed, 22 insertions, 4 deletions
diff --git a/arch/tile/mm/mmap.c b/arch/tile/mm/mmap.c index f96f4cec602a..851a94e6ae58 100644 --- a/arch/tile/mm/mmap.c +++ b/arch/tile/mm/mmap.c @@ -58,18 +58,36 @@ void arch_pick_mmap_layout(struct mm_struct *mm) #else int is_32bit = 0; #endif + unsigned long random_factor = 0UL; + + /* + * 8 bits of randomness in 32bit mmaps, 24 address space bits + * 12 bits of randomness in 64bit mmaps, 28 address space bits + */ + if (current->flags & PF_RANDOMIZE) { + if (is_32bit) + random_factor = get_random_int() % (1<<8); + else + random_factor = get_random_int() % (1<<12); + + random_factor <<= PAGE_SHIFT; + } /* * Use standard layout if the expected stack growth is unlimited * or we are running native 64 bits. */ - if (!is_32bit || rlimit(RLIMIT_STACK) == RLIM_INFINITY) { - mm->mmap_base = TASK_UNMAPPED_BASE; + if (rlimit(RLIMIT_STACK) == RLIM_INFINITY) { + mm->mmap_base = TASK_UNMAPPED_BASE + random_factor; mm->get_unmapped_area = arch_get_unmapped_area; - mm->unmap_area = arch_unmap_area; } else { mm->mmap_base = mmap_base(mm); mm->get_unmapped_area = arch_get_unmapped_area_topdown; - mm->unmap_area = arch_unmap_area_topdown; } } + +unsigned long arch_randomize_brk(struct mm_struct *mm) +{ + unsigned long range_end = mm->brk + 0x02000000; + return randomize_range(mm->brk, range_end, 0) ? : mm->brk; +} |