From: Arnd Bergmann Date: Fri, 2 Feb 2018 16:27:31 +0100 Subject: drm/nouveau: nouveau: use larger buffer in nvif_vmm_map Git-commit: 9dfbd7319909a948146f5c3438f7bd86c2c53cb6 Patch-mainline: v4.18-rc1 References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166 gcc points out a buffer that is clearly too small to be used in a meaningful way, as the 'sizeof(*args) + argc > sizeof(stack)' will always fail: In function 'memcpy', inlined from 'nvif_vmm_map' at drivers/gpu/drm/nouveau/nvif/vmm.c:55:2: include/linux/string.h:353:9: error: '__builtin_memcpy' offset 40 is out of the bounds [0, 16] of object 'stack' with type 'u8[16]' {aka 'unsigned char[16]'} [-Werror=array-bounds] return __builtin_memcpy(p, q, size); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/gpu/drm/nouveau/nvif/vmm.c: In function 'nvif_vmm_map': drivers/gpu/drm/nouveau/nvif/vmm.c:40:5: note: 'stack' declared here This makes the buffer large enough so it should serve the purpose that the author presumably had in mind. Alternatively we could just get rid of it completely and simplify the code at the cost of always doing the kmalloc (as we do in the current version). Fixes: 920d2b5ef215 ("drm/nouveau/mmu: define user interfaces to mmu vmm opertaions") Signed-off-by: Arnd Bergmann Signed-off-by: Ben Skeggs Acked-by: Petr Tesarik --- drivers/gpu/drm/nouveau/nvif/vmm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/gpu/drm/nouveau/nvif/vmm.c +++ b/drivers/gpu/drm/nouveau/nvif/vmm.c @@ -37,7 +37,7 @@ nvif_vmm_map(struct nvif_vmm *vmm, u64 a struct nvif_mem *mem, u64 offset) { struct nvif_vmm_map_v0 *args; - u8 stack[16]; + u8 stack[48]; int ret; if (sizeof(*args) + argc > sizeof(stack)) {