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authorNicolas Pitre <nico@fluxnic.net>2010-06-14 16:27:19 -0400
committerNicolas Pitre <nico@fluxnic.net>2010-06-14 21:22:11 -0400
commit990cb8acf23cab19a2930f1ed5e7dc108f89079b (patch)
tree005c4b9343ae0fac6f9b561ab3c6f3db06fbfce0
parent7e27d6e778cd87b6f2415515d7127eba53fe5d02 (diff)
[ARM] implement arch_randomize_brk()
For this feature to take effect, CONFIG_COMPAT_BRK must be turned off. This can safely be turned off for any EABI user space versions. Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
-rw-r--r--arch/arm/include/asm/elf.h3
-rw-r--r--arch/arm/kernel/process.c7
2 files changed, 10 insertions, 0 deletions
diff --git a/arch/arm/include/asm/elf.h b/arch/arm/include/asm/elf.h
index 51662feb9f1..0a96e8c1b82 100644
--- a/arch/arm/include/asm/elf.h
+++ b/arch/arm/include/asm/elf.h
@@ -121,4 +121,7 @@ int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs);
extern void elf_set_personality(const struct elf32_hdr *);
#define SET_PERSONALITY(ex) elf_set_personality(&(ex))
+extern unsigned long arch_randomize_brk(struct mm_struct *mm);
+#define arch_randomize_brk arch_randomize_brk
+
#endif
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index acf5e6fdb6d..1c6eb7ed964 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -28,6 +28,7 @@
#include <linux/tick.h>
#include <linux/utsname.h>
#include <linux/uaccess.h>
+#include <linux/random.h>
#include <asm/leds.h>
#include <asm/processor.h>
@@ -421,3 +422,9 @@ unsigned long get_wchan(struct task_struct *p)
} while (count ++ < 16);
return 0;
}
+
+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;
+}