Hi Dan,
On Fri, May 14, 2021 at 6:54 AM Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:
>
> Hello Joseph Kogut,
>
> The patch 70556e24e18e: "drm: remove usage of drm_pci_alloc/free"
> from Apr 22, 2021, leads to the following static checker warning:
>
> drivers/gpu/drm/drm_bufs.c:1090 drm_legacy_addbufs_pci()
> warn: inconsistent returns '&dev->struct_mutex'.
> Locked on : 988
> Unlocked on: 938,944,951,959,973,1005,1042,1060,1090
>
> drivers/gpu/drm/drm_bufs.c
> 965 temp_pagelist = kmalloc_array(dma->page_count + (count << page_order),
> 966 sizeof(*dma->pagelist),
> 967 GFP_KERNEL);
> 968 if (!temp_pagelist) {
> 969 kfree(entry->buflist);
> 970 kfree(entry->seglist);
> 971 mutex_unlock(&dev->struct_mutex);
> 972 atomic_dec(&dev->buf_alloc);
> 973 return -ENOMEM;
>
> There is a bunch of clean up happenning on the existing returns.
>
> 974 }
> 975 memcpy(temp_pagelist,
> 976 dma->pagelist, dma->page_count * sizeof(*dma->pagelist));
> 977 DRM_DEBUG("pagelist: %d entries\n",
> 978 dma->page_count + (count << page_order));
> 979
> 980 entry->buf_size = size;
> 981 entry->page_order = page_order;
> 982 byte_count = 0;
> 983 page_count = 0;
> 984
> 985 while (entry->buf_count < count) {
> 986 dmah = kmalloc(sizeof(drm_dma_handle_t), GFP_KERNEL);
> 987 if (!dmah)
> 988 return -ENOMEM;
>
> This new return has no clean up. We a mutex_unlock(&dev->struct_mutex).
>
> 989
> 990 dmah->size = total;
> 991 dmah->vaddr = dma_alloc_coherent(dev->dev,
> 992 dmah->size,
> 993 &dmah->busaddr,
> 994 GFP_KERNEL);
> 995 if (!dmah->vaddr) {
> 996 kfree(dmah);
> 997
> 998 /* Set count correctly so we free the proper amount. */
> 999 entry->buf_count = count;
> 1000 entry->seg_count = count;
> 1001 drm_cleanup_buf_error(dev, entry);
> 1002 kfree(temp_pagelist);
> 1003 mutex_unlock(&dev->struct_mutex);
> 1004 atomic_dec(&dev->buf_alloc);
> 1005 return -ENOMEM;
> 1006 }
> 1007 entry->seglist[entry->seg_count++] = dmah;
> 1008 for (i = 0; i < (1 << page_order); i++) {
> 1009 DRM_DEBUG("page %d @ 0x%08lx\n",
>
> regards,
> dan carpenter
Thanks for the report, I'll follow up with a patch to fix this.
Best,
Joseph
