The new amdgpu driver passes a user space pointer in a 64-bit structure member, which is the correct way to do it, but it attempts to directly cast it to a __user pointer in the kernel, which causes a warning in three places:
drm/amd/amdgpu/amdgpu_cs.c: In function 'amdgpu_cs_parser_init': drm/amd/amdgpu/amdgpu_cs.c:180:21: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] chunk_array_user = (uint64_t __user *)(cs->in.chunks);
This changes all three to add an intermediate cast to 'unsigned long' as other drivers do. This avoids the warning and works correctly on both 32-bit and 64-bit architectures.
Signed-off-by: Arnd Bergmann arnd@arndb.de
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c index cb3c274edb0a..fd16652aa277 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c @@ -177,7 +177,7 @@ int amdgpu_cs_parser_init(struct amdgpu_cs_parser *p, void *data)
/* get chunks */ INIT_LIST_HEAD(&p->validated); - chunk_array_user = (uint64_t __user *)(cs->in.chunks); + chunk_array_user = (uint64_t __user *)(unsigned long)(cs->in.chunks); if (copy_from_user(chunk_array, chunk_array_user, sizeof(uint64_t)*cs->in.num_chunks)) { ret = -EFAULT; @@ -197,7 +197,7 @@ int amdgpu_cs_parser_init(struct amdgpu_cs_parser *p, void *data) struct drm_amdgpu_cs_chunk user_chunk; uint32_t __user *cdata;
- chunk_ptr = (void __user *)chunk_array[i]; + chunk_ptr = (void __user *)(unsigned long)chunk_array[i]; if (copy_from_user(&user_chunk, chunk_ptr, sizeof(struct drm_amdgpu_cs_chunk))) { ret = -EFAULT; @@ -208,7 +208,7 @@ int amdgpu_cs_parser_init(struct amdgpu_cs_parser *p, void *data) p->chunks[i].length_dw = user_chunk.length_dw;
size = p->chunks[i].length_dw; - cdata = (void __user *)user_chunk.chunk_data; + cdata = (void __user *)(unsigned long)user_chunk.chunk_data; p->chunks[i].user_ptr = cdata;
p->chunks[i].kdata = drm_malloc_ab(size, sizeof(uint32_t));
On 07.10.2015 09:41, Arnd Bergmann wrote:
The new amdgpu driver passes a user space pointer in a 64-bit structure member, which is the correct way to do it, but it attempts to directly cast it to a __user pointer in the kernel, which causes a warning in three places:
drm/amd/amdgpu/amdgpu_cs.c: In function 'amdgpu_cs_parser_init': drm/amd/amdgpu/amdgpu_cs.c:180:21: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] chunk_array_user = (uint64_t __user *)(cs->in.chunks);
This changes all three to add an intermediate cast to 'unsigned long' as other drivers do. This avoids the warning and works correctly on both 32-bit and 64-bit architectures.
Signed-off-by: Arnd Bergmann arnd@arndb.de
Well if I'm not completely mistaken this is the second time we need to fix this because somebody thought the cast was unnecessary.
Anyway the patch is Reviewed-by: Christian König christian.koenig@amd.com and I'm going to keep an eye open for the next time somebody tries to remove this.
Regards, Christian.
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c index cb3c274edb0a..fd16652aa277 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c @@ -177,7 +177,7 @@ int amdgpu_cs_parser_init(struct amdgpu_cs_parser *p, void *data)
/* get chunks */ INIT_LIST_HEAD(&p->validated);
- chunk_array_user = (uint64_t __user *)(cs->in.chunks);
- chunk_array_user = (uint64_t __user *)(unsigned long)(cs->in.chunks); if (copy_from_user(chunk_array, chunk_array_user, sizeof(uint64_t)*cs->in.num_chunks)) { ret = -EFAULT;
@@ -197,7 +197,7 @@ int amdgpu_cs_parser_init(struct amdgpu_cs_parser *p, void *data) struct drm_amdgpu_cs_chunk user_chunk; uint32_t __user *cdata;
chunk_ptr = (void __user *)chunk_array[i];
chunk_ptr = (void __user *)(unsigned long)chunk_array[i];@@ -208,7 +208,7 @@ int amdgpu_cs_parser_init(struct amdgpu_cs_parser *p, void *data) p->chunks[i].length_dw = user_chunk.length_dw;
size = p->chunks[i].length_dw;
cdata = (void __user *)user_chunk.chunk_data;
cdata = (void __user *)(unsigned long)user_chunk.chunk_data;p->chunks[i].user_ptr = cdata;
p->chunks[i].kdata = drm_malloc_ab(size, sizeof(uint32_t));
On Wednesday 07 October 2015 10:57:11 Christian König wrote:
On 07.10.2015 09:41, Arnd Bergmann wrote:
The new amdgpu driver passes a user space pointer in a 64-bit structure member, which is the correct way to do it, but it attempts to directly cast it to a __user pointer in the kernel, which causes a warning in three places:
drm/amd/amdgpu/amdgpu_cs.c: In function 'amdgpu_cs_parser_init': drm/amd/amdgpu/amdgpu_cs.c:180:21: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] chunk_array_user = (uint64_t __user *)(cs->in.chunks);
This changes all three to add an intermediate cast to 'unsigned long' as other drivers do. This avoids the warning and works correctly on both 32-bit and 64-bit architectures.
Signed-off-by: Arnd Bergmann arnd@arndb.de
Well if I'm not completely mistaken this is the second time we need to fix this because somebody thought the cast was unnecessary.
Anyway the patch is Reviewed-by: Christian König christian.koenig@amd.com and I'm going to keep an eye open for the next time somebody tries to remove this.
Ok, thanks.
I guess I should have added
Fixes: e60b344f6c0eff ("drm/amdgpu: optimize amdgpu_parser_init")
Arnd
On Wed, Oct 7, 2015 at 5:18 AM, Arnd Bergmann arnd@arndb.de wrote:
On Wednesday 07 October 2015 10:57:11 Christian König wrote:
On 07.10.2015 09:41, Arnd Bergmann wrote:
The new amdgpu driver passes a user space pointer in a 64-bit structure member, which is the correct way to do it, but it attempts to directly cast it to a __user pointer in the kernel, which causes a warning in three places:
drm/amd/amdgpu/amdgpu_cs.c: In function 'amdgpu_cs_parser_init': drm/amd/amdgpu/amdgpu_cs.c:180:21: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] chunk_array_user = (uint64_t __user *)(cs->in.chunks);
This changes all three to add an intermediate cast to 'unsigned long' as other drivers do. This avoids the warning and works correctly on both 32-bit and 64-bit architectures.
Signed-off-by: Arnd Bergmann arnd@arndb.de
Well if I'm not completely mistaken this is the second time we need to fix this because somebody thought the cast was unnecessary.
Anyway the patch is Reviewed-by: Christian König christian.koenig@amd.com and I'm going to keep an eye open for the next time somebody tries to remove this.
Ok, thanks.
I guess I should have added
Fixes: e60b344f6c0eff ("drm/amdgpu: optimize amdgpu_parser_init")
Applied this that comment added.
Thanks!
Alex
Arnd
dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel
On Wed, Oct 07, 2015 at 10:57:11AM +0200, Christian König wrote:
On 07.10.2015 09:41, Arnd Bergmann wrote:
The new amdgpu driver passes a user space pointer in a 64-bit structure member, which is the correct way to do it, but it attempts to directly cast it to a __user pointer in the kernel, which causes a warning in three places:
drm/amd/amdgpu/amdgpu_cs.c: In function 'amdgpu_cs_parser_init': drm/amd/amdgpu/amdgpu_cs.c:180:21: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] chunk_array_user = (uint64_t __user *)(cs->in.chunks);
This changes all three to add an intermediate cast to 'unsigned long' as other drivers do. This avoids the warning and works correctly on both 32-bit and 64-bit architectures.
Signed-off-by: Arnd Bergmann arnd@arndb.de
Well if I'm not completely mistaken this is the second time we need to fix this because somebody thought the cast was unnecessary.
Anyway the patch is Reviewed-by: Christian König christian.koenig@amd.com and I'm going to keep an eye open for the next time somebody tries to remove this.
We use
static inline void __user *to_user_ptr(u64 address) { return (void __user *)(uintptr_t)address; }
to make the intention clear and hide the cast from prying eyes. -Chris
dri-devel@lists.freedesktop.org
-
Alex Deucher -
Arnd Bergmann -
Chris Wilson -
Christian König