https://bugzilla.kernel.org/show_bug.cgi?id=188631
Bug ID: 188631 Summary: Function vc4_cl_lookup_bos() does not set error code when the call to drm_malloc_ab() fails Product: Drivers Version: 2.5 Kernel Version: linux-4.9-rc6 Hardware: All OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: Video(DRI - non Intel) Assignee: drivers_video-dri@kernel-bugs.osdl.org Reporter: bianpan2010@ruc.edu.cn Regression: No
Function drm_malloc_ab() returns a NULL pointer if there is no enough memory. In function vc4_cl_lookup_bos() defined in file file drivers/gpu/drm/vc4/vc4_gem.c, varaible ret takes the return error code. When the call to drm_malloc_ab() (at line 545) fails, however, ret is not set to a negative integer, and as a result, 0 will be returned. 0 indicates that there is no error, which is contrary to the fact. Maybe it is better to assign "-ENOMEM" to ret when the check of the return value of drm_malloc_ab() fails. Codes related to this bug are summarised as follows.
vc4_cl_lookup_bos @@ drivers/gpu/drm/vc4/vc4_gem.c 518 static int 519 vc4_cl_lookup_bos(struct drm_device *dev, 520 struct drm_file *file_priv, 521 struct vc4_exec_info *exec) 522 { 523 struct drm_vc4_submit_cl *args = exec->args; 524 uint32_t *handles; 525 int ret = 0; ... 538 exec->bo = drm_calloc_large(exec->bo_count, 539 sizeof(struct drm_gem_cma_object *)); 540 if (!exec->bo) { 541 DRM_ERROR("Failed to allocate validated BO pointers\n"); 542 return -ENOMEM; 543 } 544 545 handles = drm_malloc_ab(exec->bo_count, sizeof(uint32_t)); 546 if (!handles) { 547 DRM_ERROR("Failed to allocate incoming GEM handles\n"); 548 goto fail; // insert "ret = -ENOMEM;" before this jump instruction? 549 } ... 575 fail: 576 drm_free_large(handles); 577 return ret; 578 }
Thanks very much!