2021-08-24 22:56:36

by Nathan Chancellor

Subject: [PATCH 2/3] drm/i915/selftests: Always initialize err in igt_dmabuf_import_same_driver_lmem()

Clang warns:

drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c:127:13: warning:
variable 'err' is used uninitialized whenever 'if' condition is false
[-Wsometimes-uninitialized]
} else if (PTR_ERR(import) != -EOPNOTSUPP) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c:138:9: note:
uninitialized use occurs here
return err;
^~~
drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c:127:9: note: remove
the 'if' if its condition is always true
} else if (PTR_ERR(import) != -EOPNOTSUPP) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c:95:9: note:
initialize the variable 'err' to silence this warning
int err;
^
= 0

The test is expected to pass if i915_gem_prime_import() returns
-EOPNOTSUPP so initialize err to zero in this case.

Fixes: cdb35d1ed6d2 ("drm/i915/gem: Migrate to system at dma-buf attach time (v7)")
Reported-by: Dan Carpenter <[email protected]>
Signed-off-by: Nathan Chancellor <[email protected]>
---
drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c
index 532c7955b300..4a6bb64c3a35 100644
--- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c
@@ -128,6 +128,8 @@ static int igt_dmabuf_import_same_driver_lmem(void *arg)
pr_err("i915_gem_prime_import failed with the wrong err=%ld\n",
PTR_ERR(import));
err = PTR_ERR(import);
+ } else {
+ err = 0;
}

dma_buf_put(dmabuf);
--
2.33.0

2021-08-25 10:01:38

by Thomas Hellström

Subject: Re: [PATCH 2/3] drm/i915/selftests: Always initialize err in igt_dmabuf_import_same_driver_lmem()

On 8/25/21 12:54 AM, Nathan Chancellor wrote:
> Clang warns:
>
> drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c:127:13: warning:
> variable 'err' is used uninitialized whenever 'if' condition is false
> [-Wsometimes-uninitialized]
> } else if (PTR_ERR(import) != -EOPNOTSUPP) {
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c:138:9: note:
> uninitialized use occurs here
> return err;
> ^~~
> drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c:127:9: note: remove
> the 'if' if its condition is always true
> } else if (PTR_ERR(import) != -EOPNOTSUPP) {
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c:95:9: note:
> initialize the variable 'err' to silence this warning
> int err;
> ^
> = 0
>
> The test is expected to pass if i915_gem_prime_import() returns
> -EOPNOTSUPP so initialize err to zero in this case.
>
> Fixes: cdb35d1ed6d2 ("drm/i915/gem: Migrate to system at dma-buf attach time (v7)")
> Reported-by: Dan Carpenter <[email protected]>
> Signed-off-by: Nathan Chancellor <[email protected]>

Reviewed-by: Thomas Hellström <[email protected]>