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drm/nouveau: nouveau: use larger buffer in nvif_vmm_map 

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: 920d2b5ef2 ("drm/nouveau/mmu: define user interfaces to mmu vmm opertaions")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
hifive-unleashed-5.1
Arnd Bergmann 2018-02-02 16:27:31 +01:00 committed by Ben Skeggs
parent 1fafef9dfe
commit 9dfbd73199
1 changed files with 1 additions and 1 deletions
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2
drivers/gpu/drm/nouveau/nvif/vmm.c
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@ -37,7 +37,7 @@ nvif_vmm_map(struct nvif_vmm *vmm, u64 addr, u64 size, void *argv, u32 argc,
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)) {