[PATCH] gpu: drm: i915: fix error return code of igt_threaded_blt()

[PATCH] gpu: drm: i915: fix error return code of igt_threaded_blt()

[Jia-Ju Bai]

When kcalloc() returns NULL to tsk or thread, no error code of 
igt_threaded_blt() is returned.
To fix this bug, -ENOMEM is returned as error code.

Fixes: 0e99f939f08f ("drm/i915/selftests/blt: add some kthreads into the mix")
Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
---
 drivers/gpu/drm/i915/gem/selftests/i915_gem_object_blt.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_object_blt.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_object_blt.c
index 23b6e11bbc3e..b54ba8a1fcec 100644
--- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_object_blt.c
+++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_object_blt.c
@@ -471,11 +471,13 @@ static int igt_threaded_blt(struct intel_engine_cs *engine,
 
 	tsk = kcalloc(n_cpus, sizeof(struct task_struct *), GFP_KERNEL);
 	if (!tsk)
-		return 0;
+		return -ENOMEM;
 
 	thread = kcalloc(n_cpus, sizeof(struct igt_thread_arg), GFP_KERNEL);
-	if (!thread)
+	if (!thread) {
+		err = -ENOMEM;
 		goto out_tsk;
+	}
 
 	thread[0].file = mock_file(engine->i915);
 	if (IS_ERR(thread[0].file)) {
-- 
2.17.1

Re: [PATCH] gpu: drm: i915: fix error return code of igt_threaded_blt()

[Chris Wilson]

Quoting Jia-Ju Bai (2021-03-08 09:07:22)
> When kcalloc() returns NULL to tsk or thread, no error code of 
> igt_threaded_blt() is returned.
> To fix this bug, -ENOMEM is returned as error code.

Because we decided to skip the test if it could not be run due to
insufficient memory, as opposed to an internal allocation failure from
the driver.
-Chris