patch "staging: comedi: gsc_hpdi: check dma_alloc_coherent() return value" added to staging-linus

This is a note to let you know that I've just added the patch titled

staging: comedi: gsc_hpdi: check dma_alloc_coherent() return value

to my staging git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git
in the staging-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From ab42b48f32d4c766420c3499ee9c0289b7028182 Mon Sep 17 00:00:00 2001
From: Ian Abbott <[email protected]>
Date: Mon, 16 Dec 2019 11:08:23 +0000
Subject: staging: comedi: gsc_hpdi: check dma_alloc_coherent() return value

The "auto-attach" handler function gsc_hpdi_auto_attach() calls dma_alloc_coherent() in a loop to allocate some DMA data buffers, and also calls it to allocate a buffer for a DMA descriptor chain. However, it does not check the return value of any of these calls. Change gsc_hpdi_auto_attach() to return -ENOMEM if any of these dma_alloc_coherent() calls fail. This will result in the comedi core calling the "detach" handler gsc_hpdi_detach() as part of the clean-up, which will call gsc_hpdi_free_dma() to free any allocated DMA coherent memory buffers.

---
 drivers/staging/comedi/drivers/gsc_hpdi.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

index 4bdf44d82879..dc62db1ee1dd 100644
@@ -623,6 +623,11 @@ static int gsc_hpdi_auto_attach(struct comedi_device *dev,
 		    dma_alloc_coherent(&pcidev->dev, DMA_BUFFER_SIZE,
 				       &devpriv->dio_buffer_phys_addr[i],
 				       GFP_KERNEL);
+		if (!devpriv->dio_buffer[i]) {
+			dev_warn(dev->class_dev,
+				 "failed to allocate DMA buffer\n");
+			return -ENOMEM;
+		}
 	}
 	/* allocate dma descriptors */
 	devpriv->dma_desc = dma_alloc_coherent(&pcidev->dev,

@@ -630,6 +635,11 @@ static int gsc_hpdi_auto_attach(struct comedi_device *dev,
 					       NUM_DMA_DESCRIPTORS,
 					       &devpriv->dma_desc_phys_addr,
 					       GFP_KERNEL);
+	if (!devpriv->dma_desc) {
+		dev_warn(dev->class_dev,
+			 "failed to allocate DMA descriptors\n");
+		return -ENOMEM;
+	}
 	if (devpriv->dma_desc_phys_addr & 0xf) {
 		dev_warn(dev->class_dev,
 			 " dma descriptors not quad-word aligned (bug)\n");

2.24.1