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authorNicolas Pitre <nico@fluxnic.net>2010-06-14 21:16:19 -0400
committerNicolas Pitre <nico@fluxnic.net>2010-06-14 21:22:11 -0400
commitcc92c28b2db5b406657ecc05235d4ca4e222ae34 (patch)
tree202734aa4fc2e5b9953deb3fa8a5d249e21a7fe2
parent990cb8acf23cab19a2930f1ed5e7dc108f89079b (diff)
[ARM] add address randomization to mmap()
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
-rw-r--r--arch/arm/mm/mmap.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c
index f5abc51c5a0..4f5b39687df 100644
--- a/arch/arm/mm/mmap.c
+++ b/arch/arm/mm/mmap.c
@@ -7,6 +7,7 @@
#include <linux/shm.h>
#include <linux/sched.h>
#include <linux/io.h>
+#include <linux/random.h>
#include <asm/cputype.h>
#include <asm/system.h>
@@ -80,6 +81,9 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
start_addr = addr = TASK_UNMAPPED_BASE;
mm->cached_hole_size = 0;
}
+ /* 8 bits of randomness in 20 address space bits */
+ if (current->flags & PF_RANDOMIZE)
+ addr += (get_random_int() % (1 << 8)) << PAGE_SHIFT;
full_search:
if (do_align)