[Intel-gfx] [bug report] drm/i915/gem: Correct the locking and pin pattern for dma-buf (v8)

[Intel-gfx] [bug report] drm/i915/gem: Correct the locking and pin pattern for dma-buf (v8)

[Dan Carpenter]

Nathan has probably already sent fixes for these.  Nathan, could you CC
kernel-janitors on static checker fixes?  That way we wouldn't send so
many duplicate patches.

Uninitialized variable warnings are really frustrating.  We disabled the
GCC warning for them because the new GCC is crap.  So now they take up
a lot of my time.  A few of these are because Smatch doesn't always know
when we enter loops, but more than half are clear bugs.

drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c:189 i915_gem_dmabuf_attach() error: uninitialized symbol 'err'.
drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c:80 igt_dmabuf_import_self() error: uninitialized symbol 'import_obj'.
drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c:104 igt_dmabuf_import_same_driver_lmem() error: uninitialized symbol 'dmabuf'.
drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c:138 igt_dmabuf_import_same_driver_lmem() error: uninitialized symbol 'err'.
drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c:158 igt_dmabuf_import_same_driver() error: uninitialized symbol 'dmabuf'.
drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c:231 igt_dmabuf_import_same_driver() error: uninitialized symbol 'import_obj'.
drivers/gpu/drm/i915/gem/selftests/i915_gem_migrate.c:197 igt_lmem_pages_migrate() error: uninitialized symbol 'err'.
drivers/gpu/drm/i915/gt/selftest_hangcheck.c:465 igt_reset_nop_engine() error: uninitialized symbol 'err'.
drivers/gpu/drm/i915/gt/selftest_hangcheck.c:580 igt_reset_fail_engine() error: uninitialized symbol 'err'.
drivers/gpu/drm/i915/gt/selftest_migrate.c:102 copy() error: uninitialized symbol 'rq'.
drivers/gpu/drm/i915/gt/selftest_migrate.c:113 copy() error: uninitialized symbol 'vaddr'.
drivers/gpu/drm/i915/gt/selftest_migrate.c:182 clear() error: uninitialized symbol 'rq'.
drivers/gpu/drm/i915/gt/selftest_migrate.c:193 clear() error: uninitialized symbol 'vaddr'.
drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c:819 __unwind_incomplete_requests() error: uninitialized symbol 'pl'.

regards,
dan carpenter

Re: [Intel-gfx] [bug report] drm/i915/gem: Correct the locking and pin pattern for dma-buf (v8)

[Nathan Chancellor]

On 8/13/2021 4:31 AM, Dan Carpenter wrote:
> Nathan has probably already sent fixes for these.  Nathan, could you CC
> kernel-janitors on static checker fixes?  That way we wouldn't send so
> many duplicate patches.

Sure. I did not send any fixes prior to this email but I just sent
https://lore.kernel.org/r/20210813171158.2665823-1-nathan@kernel.org/ 
with kernel-janitors and you CC'd.

> Uninitialized variable warnings are really frustrating.  We disabled the
> GCC warning for them because the new GCC is crap.  So now they take up
> a lot of my time.  A few of these are because Smatch doesn't always know
> when we enter loops, but more than half are clear bugs.
> 
> drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c:189 i915_gem_dmabuf_attach() error: uninitialized symbol 'err'.
> drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c:80 igt_dmabuf_import_self() error: uninitialized symbol 'import_obj'.
> drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c:104 igt_dmabuf_import_same_driver_lmem() error: uninitialized symbol 'dmabuf'.
> drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c:138 igt_dmabuf_import_same_driver_lmem() error: uninitialized symbol 'err'.
> drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c:158 igt_dmabuf_import_same_driver() error: uninitialized symbol 'dmabuf'.
> drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c:231 igt_dmabuf_import_same_driver() error: uninitialized symbol 'import_obj'.
> drivers/gpu/drm/i915/gem/selftests/i915_gem_migrate.c:197 igt_lmem_pages_migrate() error: uninitialized symbol 'err'.

...

> drivers/gpu/drm/i915/gt/selftest_hangcheck.c:465 igt_reset_nop_engine() error: uninitialized symbol 'err'.
> drivers/gpu/drm/i915/gt/selftest_hangcheck.c:580 igt_reset_fail_engine() error: uninitialized symbol 'err'.

Clang caught these two but none of the rest and it is an obvious fix so 
that is the only one I am going to fix.

> drivers/gpu/drm/i915/gt/selftest_migrate.c:102 copy() error: uninitialized symbol 'rq'.
> drivers/gpu/drm/i915/gt/selftest_migrate.c:113 copy() error: uninitialized symbol 'vaddr'.
> drivers/gpu/drm/i915/gt/selftest_migrate.c:182 clear() error: uninitialized symbol 'rq'.
> drivers/gpu/drm/i915/gt/selftest_migrate.c:193 clear() error: uninitialized symbol 'vaddr'.
> drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c:819 __unwind_incomplete_requests() error: uninitialized symbol 'pl'.

Cheers,
Nathan