diff options
| author | David S. Miller <davem@sunset.davemloft.net> | 2006-03-17 17:42:57 -0800 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2006-03-20 01:16:37 -0800 |
| commit | 05f9ca83596c7801549a2b4eba469d51baf5480f (patch) | |
| tree | 22270db01a13dda0af9b158662712f9e6b6a934c | |
| parent | d61e16df940e02e25679bdc1aee8c25786f6de90 (diff) | |
[SPARC64]: Randomize mm->mmap_base when PF_RANDOMIZE is set.
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | arch/sparc64/kernel/sys_sparc.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/arch/sparc64/kernel/sys_sparc.c b/arch/sparc64/kernel/sys_sparc.c index 9019b41fc02a..7a869138c37f 100644 --- a/arch/sparc64/kernel/sys_sparc.c +++ b/arch/sparc64/kernel/sys_sparc.c @@ -25,6 +25,7 @@ #include <linux/syscalls.h> #include <linux/ipc.h> #include <linux/personality.h> +#include <linux/random.h> #include <asm/uaccess.h> #include <asm/ipc.h> @@ -358,6 +359,17 @@ unsigned long get_fb_unmapped_area(struct file *filp, unsigned long orig_addr, u /* Essentially the same as PowerPC... */ void arch_pick_mmap_layout(struct mm_struct *mm) { + unsigned long random_factor = 0UL; + + if (current->flags & PF_RANDOMIZE) { + random_factor = get_random_int(); + if (test_thread_flag(TIF_32BIT)) + random_factor &= ((1 * 1024 * 1024) - 1); + else + random_factor = ((random_factor << PAGE_SHIFT) & + 0xffffffffUL); + } + /* * Fall back to the standard layout if the personality * bit is set, or if the expected stack growth is unlimited: @@ -366,7 +378,7 @@ void arch_pick_mmap_layout(struct mm_struct *mm) (current->personality & ADDR_COMPAT_LAYOUT) || current->signal->rlim[RLIMIT_STACK].rlim_cur == RLIM_INFINITY || sysctl_legacy_va_layout) { - mm->mmap_base = TASK_UNMAPPED_BASE; + mm->mmap_base = TASK_UNMAPPED_BASE + random_factor; mm->get_unmapped_area = arch_get_unmapped_area; mm->unmap_area = arch_unmap_area; } else { @@ -380,7 +392,7 @@ void arch_pick_mmap_layout(struct mm_struct *mm) if (gap > (task_size / 6 * 5)) gap = (task_size / 6 * 5); - mm->mmap_base = task_size - (gap & PAGE_MASK); + mm->mmap_base = PAGE_ALIGN(task_size - gap - random_factor); mm->get_unmapped_area = arch_get_unmapped_area_topdown; mm->unmap_area = arch_unmap_area_topdown; } |