[PATCH 11/11] [RFC] drm/i915/dp: fix array overflow warning
From: Arnd Bergmann <arnd@kernel.org>
Date: 2021-03-22 16:07:51
Also in:
ath11k, cgroups, dri-devel, intel-gfx, linux-arm-kernel, linux-scsi, linux-security-module, linux-wireless, lkml
Subsystem:
drm drivers, intel drm display for xe and i915 drivers, intel drm i915 driver (meteor lake, dg2 and older excluding poulsbo, moorestown and derivative), the rest · Maintainers:
David Airlie, Simona Vetter, Jani Nikula, Rodrigo Vivi, Joonas Lahtinen, Tvrtko Ursulin, Linus Torvalds
From: Arnd Bergmann <arnd@arndb.de>
gcc-11 warns that intel_dp_check_mst_status() has a local array of
fourteen bytes and passes the last four bytes into a function that
expects a six-byte array:
drivers/gpu/drm/i915/display/intel_dp.c: In function ‘intel_dp_check_mst_status’:
drivers/gpu/drm/i915/display/intel_dp.c:4556:22: error: ‘drm_dp_channel_eq_ok’ reading 6 bytes from a region of size 4 [-Werror=stringop-overread]
4556 | !drm_dp_channel_eq_ok(&esi[10], intel_dp->lane_count)) {
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/i915/display/intel_dp.c:4556:22: note: referencing argument 1 of type ‘const u8 *’ {aka ‘const unsigned char *’}
In file included from drivers/gpu/drm/i915/display/intel_dp.c:38:
include/drm/drm_dp_helper.h:1459:6: note: in a call to function ‘drm_dp_channel_eq_ok’
1459 | bool drm_dp_channel_eq_ok(const u8 link_status[DP_LINK_STATUS_SIZE],
| ^~~~~~~~~~~~~~~~~~~~
Clearly something is wrong here, but I can't quite figure out what.
Changing the array size to 16 bytes avoids the warning, but is
probably the wrong solution here.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
drivers/gpu/drm/i915/display/intel_dp.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 8c12d5375607..830e2515f119 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -65,7 +65,7 @@
#include "intel_vdsc.h"
#include "intel_vrr.h"
-#define DP_DPRX_ESI_LEN 14
+#define DP_DPRX_ESI_LEN 16
/* DP DSC throughput values used for slice count calculations KPixels/s */
#define DP_DSC_PEAK_PIXEL_RATE 2720000
--
2.29.2