[PATCH 1/1] drm: drm_legacy_addbufs_pci(): fix return without cleanup

Joseph Kogut joseph.kogut at gmail.com
Fri May 14 20:48:36 UTC 2021


The patch 70556e24e18e: "drm: remove usage of drm_pci_alloc/free" 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

Fix the return without cleanup by removing the early return and taking
the original return path on allocation failure, including the intended
unlocks.

Signed-off-by: Joseph Kogut <joseph.kogut at gmail.com>
---
 drivers/gpu/drm/drm_bufs.c | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/drm_bufs.c b/drivers/gpu/drm/drm_bufs.c
index 94bc1f6049c9..ea3ca81be9dd 100644
--- a/drivers/gpu/drm/drm_bufs.c
+++ b/drivers/gpu/drm/drm_bufs.c
@@ -984,17 +984,18 @@ int drm_legacy_addbufs_pci(struct drm_device *dev,
 
 	while (entry->buf_count < count) {
 		dmah = kmalloc(sizeof(drm_dma_handle_t), GFP_KERNEL);
-		if (!dmah)
-			return -ENOMEM;
-
-		dmah->size = total;
-		dmah->vaddr = dma_alloc_coherent(dev->dev,
-						 dmah->size,
-						 &dmah->busaddr,
-						 GFP_KERNEL);
-		if (!dmah->vaddr) {
-			kfree(dmah);
-
+		if (dmah) {
+			dmah->size = total;
+			dmah->vaddr = dma_alloc_coherent(dev->dev,
+							 dmah->size,
+							 &dmah->busaddr,
+							 GFP_KERNEL);
+			if (!dmah->vaddr) {
+				kfree(dmah);
+				dmah = NULL;
+			}
+		}
+		if (!dmah) {
 			/* Set count correctly so we free the proper amount. */
 			entry->buf_count = count;
 			entry->seg_count = count;
-- 
2.31.1



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