[v5,1/3] PCI: Fix off by one in dma_alias_mask allocation size
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Message ID 9DD82D05-6B9E-4AF5-9A3C-D459B75C0089@arista.com
State New
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Series
  • [v5,1/3] PCI: Fix off by one in dma_alias_mask allocation size
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Commit Message

James Sewart Nov. 29, 2019, 5:56 p.m. UTC
The number of possible devfns is 256 so the size of the bitmap for
allocations should be U8_MAX+1.

Signed-off-by: James Sewart <jamessewart@arista.com>
---
 drivers/pci/pci.c    | 2 +-
 drivers/pci/search.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

Comments

Logan Gunthorpe Nov. 29, 2019, 5:58 p.m. UTC | #1
On 2019-11-29 10:56 a.m., James Sewart wrote:
> The number of possible devfns is 256 so the size of the bitmap for
> allocations should be U8_MAX+1.
> 
> Signed-off-by: James Sewart <jamessewart@arista.com>

Looks good to me. Thanks! For the whole series:

Reviewed-by: Logan Gunthorpe <logang@deltatee.com>

> ---
>  drivers/pci/pci.c    | 2 +-
>  drivers/pci/search.c | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index a97e2571a527..0a4449a30ace 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -5876,7 +5876,7 @@ int pci_set_vga_state(struct pci_dev *dev, bool decode,
>  void pci_add_dma_alias(struct pci_dev *dev, u8 devfn)
>  {
>  	if (!dev->dma_alias_mask)
> -		dev->dma_alias_mask = bitmap_zalloc(U8_MAX, GFP_KERNEL);
> +		dev->dma_alias_mask = bitmap_zalloc(U8_MAX+1, GFP_KERNEL);
>  	if (!dev->dma_alias_mask) {
>  		pci_warn(dev, "Unable to allocate DMA alias mask\n");
>  		return;
> diff --git a/drivers/pci/search.c b/drivers/pci/search.c
> index bade14002fd8..b3633af1743b 100644
> --- a/drivers/pci/search.c
> +++ b/drivers/pci/search.c
> @@ -43,7 +43,7 @@ int pci_for_each_dma_alias(struct pci_dev *pdev,
>  	if (unlikely(pdev->dma_alias_mask)) {
>  		u8 devfn;
>  
> -		for_each_set_bit(devfn, pdev->dma_alias_mask, U8_MAX) {
> +		for_each_set_bit(devfn, pdev->dma_alias_mask, U8_MAX+1) {
>  			ret = fn(pdev, PCI_DEVID(pdev->bus->number, devfn),
>  				 data);
>  			if (ret)
>
Christoph Hellwig Dec. 2, 2019, 5:03 p.m. UTC | #2
On Fri, Nov 29, 2019 at 05:56:19PM +0000, James Sewart wrote:
> The number of possible devfns is 256 so the size of the bitmap for
> allocations should be U8_MAX+1.
> 
> Signed-off-by: James Sewart <jamessewart@arista.com>
> ---
>  drivers/pci/pci.c    | 2 +-
>  drivers/pci/search.c | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index a97e2571a527..0a4449a30ace 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -5876,7 +5876,7 @@ int pci_set_vga_state(struct pci_dev *dev, bool decode,
>  void pci_add_dma_alias(struct pci_dev *dev, u8 devfn)
>  {
>  	if (!dev->dma_alias_mask)
> -		dev->dma_alias_mask = bitmap_zalloc(U8_MAX, GFP_KERNEL);
> +		dev->dma_alias_mask = bitmap_zalloc(U8_MAX+1, GFP_KERNEL);

Missing whitespaces around the "+".

> -		for_each_set_bit(devfn, pdev->dma_alias_mask, U8_MAX) {
> +		for_each_set_bit(devfn, pdev->dma_alias_mask, U8_MAX+1) {

Same here.

Patch
diff mbox series

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index a97e2571a527..0a4449a30ace 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5876,7 +5876,7 @@  int pci_set_vga_state(struct pci_dev *dev, bool decode,
 void pci_add_dma_alias(struct pci_dev *dev, u8 devfn)
 {
 	if (!dev->dma_alias_mask)
-		dev->dma_alias_mask = bitmap_zalloc(U8_MAX, GFP_KERNEL);
+		dev->dma_alias_mask = bitmap_zalloc(U8_MAX+1, GFP_KERNEL);
 	if (!dev->dma_alias_mask) {
 		pci_warn(dev, "Unable to allocate DMA alias mask\n");
 		return;
diff --git a/drivers/pci/search.c b/drivers/pci/search.c
index bade14002fd8..b3633af1743b 100644
--- a/drivers/pci/search.c
+++ b/drivers/pci/search.c
@@ -43,7 +43,7 @@  int pci_for_each_dma_alias(struct pci_dev *pdev,
 	if (unlikely(pdev->dma_alias_mask)) {
 		u8 devfn;
 
-		for_each_set_bit(devfn, pdev->dma_alias_mask, U8_MAX) {
+		for_each_set_bit(devfn, pdev->dma_alias_mask, U8_MAX+1) {
 			ret = fn(pdev, PCI_DEVID(pdev->bus->number, devfn),
 				 data);
 			if (ret)