[ldv-project] [PATCH] umem: don't return zero on failure paths in mm_pci_probe()

[Alexey Khoroshilov]

If pci_alloc_consistent() or blk_alloc_queue() failed,
mm_pci_probe() breaks off initialization, deallocates
resources, but returns zero.

The patch adds -ENOMEM as a return value in these cases.
By the way, it adds blk_cleanup_queue() and pci_disable_device()
to fix leaks in failure handling code.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov at ispras.ru>
---
 drivers/block/umem.c | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/block/umem.c b/drivers/block/umem.c
index 4cf81b5bf0f7..960a3cadcd6b 100644
--- a/drivers/block/umem.c
+++ b/drivers/block/umem.c
@@ -808,12 +808,14 @@ static int mm_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	pci_write_config_byte(dev, PCI_LATENCY_TIMER, 0xF8);
 	pci_set_master(dev);
 
-	card->dev         = dev;
+	card->dev = dev;
 
 	csr_base = pci_resource_start(dev, 0);
 	csr_len  = pci_resource_len(dev, 0);
-	if (!csr_base || !csr_len)
-		return -ENODEV;
+	if (!csr_base || !csr_len) {
+		ret = -ENODEV;
+		goto failed_pci;
+	}
 
 	dev_printk(KERN_INFO, &dev->dev,
 	  "Micro Memory(tm) controller found (PCI Mem Module (Battery Backup))\n");
@@ -821,7 +823,8 @@ static int mm_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	if (pci_set_dma_mask(dev, DMA_BIT_MASK(64)) &&
 	    pci_set_dma_mask(dev, DMA_BIT_MASK(32))) {
 		dev_printk(KERN_WARNING, &dev->dev, "NO suitable DMA found\n");
-		return  -ENOMEM;
+		ret = -ENOMEM;
+		goto failed_pci;
 	}
 
 	ret = pci_request_regions(dev, DRIVER_NAME);
@@ -836,7 +839,6 @@ static int mm_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 		dev_printk(KERN_ERR, &card->dev->dev,
 			"Unable to remap memory region\n");
 		ret = -ENOMEM;
-
 		goto failed_remap_csr;
 	}
 
@@ -881,6 +883,7 @@ static int mm_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	if (card->mm_pages[0].desc == NULL ||
 	    card->mm_pages[1].desc == NULL) {
 		dev_printk(KERN_ERR, &card->dev->dev, "alloc failed\n");
+		ret = -ENOMEM;
 		goto failed_alloc;
 	}
 	reset_page(&card->mm_pages[0]);
@@ -891,8 +894,10 @@ static int mm_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	card->biotail = &card->bio;
 
 	card->queue = blk_alloc_queue(GFP_KERNEL);
-	if (!card->queue)
+	if (!card->queue) {
+		ret = -ENOMEM;
 		goto failed_alloc;
+	}
 
 	blk_queue_make_request(card->queue, mm_make_request);
 	card->queue->queue_lock = &card->lock;
@@ -1002,6 +1007,7 @@ static int mm_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	return 0;
 
  failed_req_irq:
+	blk_cleanup_queue(card->queue);
  failed_alloc:
 	if (card->mm_pages[0].desc)
 		pci_free_consistent(card->dev, PAGE_SIZE*2,
@@ -1016,6 +1022,8 @@ static int mm_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
  failed_remap_csr:
 	pci_release_regions(dev);
  failed_req_csr:
+ failed_pci:
+	pci_disable_device(dev);
 
 	return ret;
 }
-- 
1.9.1