| Message ID | 1415463482-8013-1-git-send-email-tinajohnson.1234@gmail.com |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Tina Johnson <tinajohnson.1234@gmail.com> Date: Sat, 8 Nov 2014 21:48:02 +0530 > Added a pci_dma_mapping_error() call to check for mapping errors before > further using the dma handle. Unchecked dma handles were found using > Coccinelle: > > @rule1@ > expression e1; > identifier x; > @@ > > *x = pci_map_single(...); > ... when != pci_dma_mapping_error(e1,x) > > Signed-off-by: Tina Johnson <tinajohnson.1234@gmail.com> > Acked-by: Julia Lawall <julia.lawall@lip6.fr> I really don't like quick fixes like this, exactly because of the kind of new bug this change is introducing. The 'trouble' label assumes that it is recovering and unwinding state when an error occurs after the DMA buffer is successfully mapped. It unconditionally does pci_unmap_single() if 'paddr' is non-zero which it might be in the error case depending upon how DMA errors are represented on a given platform. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, 10 Nov 2014, David Miller wrote: > The 'trouble' label assumes that it is recovering and unwinding state > when an error occurs after the DMA buffer is successfully mapped. > > It unconditionally does pci_unmap_single() if 'paddr' is non-zero > which it might be in the error case depending upon how DMA errors > are represented on a given platform. Sorry for the trouble and thankyou for your very helpful comment. I will send the revised patch. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/atm/eni.c b/drivers/atm/eni.c index d65975a..6450a36 100644 --- a/drivers/atm/eni.c +++ b/drivers/atm/eni.c @@ -356,6 +356,8 @@ static int do_rx_dma(struct atm_vcc *vcc,struct sk_buff *skb, if (skb) { paddr = pci_map_single(eni_dev->pci_dev,skb->data,skb->len, PCI_DMA_FROMDEVICE); + if (pci_dma_mapping_error(eni_dev->pci_dev, paddr)) + goto trouble; ENI_PRV_PADDR(skb) = paddr; if (paddr & 3) printk(KERN_CRIT DEV_LABEL "(itf %d): VCI %d has "