arm64: use simpler API for random address requests

Currently, all callers to randomize_range() set the length to 0 and
calculate end by adding a constant to the start address.  We can simplify
the API to remove a bunch of needless checks and variables.

Use the new randomize_addr(start, range) call to set the requested
address.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Jason Cooper <[email protected]>
Acked-by: Will Deacon <[email protected]>
Acked-by: Kees Cook <[email protected]>
Cc: "Russell King - ARM Linux" <[email protected]>
Cc: Catalin Marinas <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index a4f5f766af08b010e66ec04889c098a5267eee05..27b2f1387df40b61b4aa059be5650d329964da6b 100644 (file)
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -372,12 +372,8 @@ unsigned long arch_align_stack(unsigned long sp)
 
 unsigned long arch_randomize_brk(struct mm_struct *mm)
 {
-       unsigned long range_end = mm->brk;
-
        if (is_compat_task())
-               range_end += 0x02000000;
+               return randomize_page(mm->brk, 0x02000000);
        else
-               range_end += 0x40000000;
-
-       return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
+               return randomize_page(mm->brk, 0x40000000);
 }