From 67a8ab4adc2d30e3f3442a0659b887b4da83f7c2 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 30 Oct 2017 21:23:19 +0000 Subject: [PATCH] UPSTREAM: arm64: vdso: fix clock_getres for 4GiB-aligned res (cherry pick from commit c80ed088a519da53f27b798a69748eaabc66aadf) 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 Reported-by: Andrew Pinski Reported-by: Mark Salyzyn Cc: Catalin Marinas Cc: Will Deacon Signed-off-by: Will Deacon Bug: 20045882 Bug: 63737556 Change-Id: Iab5449d8515f9d655e792e3d7ce43a8f016fa2a0 --- arch/arm64/kernel/vdso/gettimeofday.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/kernel/vdso/gettimeofday.S b/arch/arm64/kernel/vdso/gettimeofday.S index e00b4671bd7c..c97ce91cf023 100644 --- a/arch/arm64/kernel/vdso/gettimeofday.S +++ b/arch/arm64/kernel/vdso/gettimeofday.S @@ -310,7 +310,7 @@ ENTRY(__kernel_clock_getres) b.ne 4f ldr x2, 6f 2: - cbz w1, 3f + cbz x1, 3f stp xzr, x2, [x1] 3: /* res == NULL. */