2024-04-13 03:18:25

by Dmitrii Bundin

Subject: [PATCH] drm/i915/guc: Fix UB due to signed int overflow

Fix compile errors of the form "FIELD_PREP: mask is not constant" caused
by signed integer constant overflow. Files affected:

drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c

Reproducible with gcc 7.5

Signed-off-by: Dmitrii Bundin <[email protected]>
---
drivers/gpu/drm/i915/gt/uc/abi/guc_klvs_abi.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gt/uc/abi/guc_klvs_abi.h b/drivers/gpu/drm/i915/gt/uc/abi/guc_klvs_abi.h
index 58012edd4eb0..8814d4cd371c 100644
--- a/drivers/gpu/drm/i915/gt/uc/abi/guc_klvs_abi.h
+++ b/drivers/gpu/drm/i915/gt/uc/abi/guc_klvs_abi.h
@@ -29,7 +29,7 @@
*/

#define GUC_KLV_LEN_MIN 1u
-#define GUC_KLV_0_KEY (0xffff << 16)
+#define GUC_KLV_0_KEY (0xffffU << 16)
#define GUC_KLV_0_LEN (0xffff << 0)
#define GUC_KLV_n_VALUE (0xffffffff << 0)

--
2.34.1

2024-05-02 10:36:47

by Dmitrii Bundin

Subject: [PATCH RESEND] drm/i915/guc: Fix UB due to signed int overflow

Fix compile errors of the form "FIELD_PREP: mask is not constant" caused
by signed integer constant overflow. Files affected:

drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c

Reproducible with gcc 7.5

See https://lore.kernel.org/r/YkwQ6%[email protected] for the gory
details as to why it triggers with older gccs only.

Signed-off-by: Dmitrii Bundin <[email protected]>
---
drivers/gpu/drm/i915/gt/uc/abi/guc_klvs_abi.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gt/uc/abi/guc_klvs_abi.h b/drivers/gpu/drm/i915/gt/uc/abi/guc_klvs_abi.h
index 58012edd4eb0..8814d4cd371c 100644
--- a/drivers/gpu/drm/i915/gt/uc/abi/guc_klvs_abi.h
+++ b/drivers/gpu/drm/i915/gt/uc/abi/guc_klvs_abi.h
@@ -29,7 +29,7 @@
*/

#define GUC_KLV_LEN_MIN 1u
-#define GUC_KLV_0_KEY (0xffff << 16)
+#define GUC_KLV_0_KEY (0xffffU << 16)
#define GUC_KLV_0_LEN (0xffff << 0)
#define GUC_KLV_n_VALUE (0xffffffff << 0)

--
2.34.1