3.16.54-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Mark Rutland <[email protected]> commit c80ed088a519da53f27b798a69748eaabc66aadf upstream. The vdso tries to check for a NULL res pointer in __kernel_clock_getres, but only checks the lower 32 bits as is uses CBZ on the W register the res pointer is held in. Thus, if the res pointer happened to be aligned to a 4GiB boundary, we'd spuriously skip storing the timespec to it, while returning a zero error code to the caller. Prevent this by checking the whole pointer, using CBZ on the X register the res pointer is held in. Fixes: 9031fefde6f2ac1d ("arm64: VDSO support") Signed-off-by: Mark Rutland <[email protected]> Reported-by: Andrew Pinski <[email protected]> Reported-by: Mark Salyzyn <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Will Deacon <[email protected]> Signed-off-by: Will Deacon <[email protected]> Signed-off-by: Ben Hutchings <[email protected]> --- arch/arm64/kernel/vdso/gettimeofday.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/arm64/kernel/vdso/gettimeofday.S +++ b/arch/arm64/kernel/vdso/gettimeofday.S @@ -186,7 +186,7 @@ ENTRY(__kernel_clock_getres) b.ne 4f ldr x2, 6f 2: - cbz w1, 3f + cbz x1, 3f stp xzr, x2, [x1] 3: /* res == NULL. */
