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-rw-r--r--arch/powerpc/include/asm/elf.h3
-rw-r--r--arch/powerpc/kernel/process.c23
2 files changed, 26 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/elf.h b/arch/powerpc/include/asm/elf.h
index 3f94d8880e6c..968b37f7a9f8 100644
--- a/arch/powerpc/include/asm/elf.h
+++ b/arch/powerpc/include/asm/elf.h
@@ -276,6 +276,9 @@ extern int arch_setup_additional_pages(struct linux_binprm *bprm,
(0x7ff >> (PAGE_SHIFT - 12)) : \
(0x3ffff >> (PAGE_SHIFT - 12)))
+extern unsigned long arch_randomize_brk(struct mm_struct *mm);
+#define arch_randomize_brk arch_randomize_brk
+
#endif /* __KERNEL__ */
/*
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 69b9d2d3cb84..30b149ce7598 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1147,3 +1147,26 @@ unsigned long arch_align_stack(unsigned long sp)
sp -= get_random_int() & ~PAGE_MASK;
return sp & ~0xf;
}
+
+static inline unsigned long brk_rnd(void)
+{
+ unsigned long rnd = 0;
+
+ /* 8MB for 32bit, 1GB for 64bit */
+ if (is_32bit_task())
+ rnd = (long)(get_random_int() % (1<<(23-PAGE_SHIFT)));
+ else
+ rnd = (long)(get_random_int() % (1<<(30-PAGE_SHIFT)));
+
+ return rnd << PAGE_SHIFT;
+}
+
+unsigned long arch_randomize_brk(struct mm_struct *mm)
+{
+ unsigned long ret = PAGE_ALIGN(mm->brk + brk_rnd());
+
+ if (ret < mm->brk)
+ return mm->brk;
+
+ return ret;
+}