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powerpc/powernv: move the dereference below the NULL test

Message ID CAPgLHd_w9B8sHg9i9msFLx8FVBypqTtDEVOt1-VBNTW4zwHTMQ@mail.gmail.com (mailing list archive)
State Not Applicable
Headers show

Commit Message

Wei Yongjun Sept. 7, 2012, 6:45 a.m. UTC 
From: Wei Yongjun <yongjun_wei@trendmicro.com.cn>

The dereference should be moved below the NULL test.

spatch with a semantic match is used to found this.
(http://coccinelle.lip6.fr/)

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
---
 arch/powerpc/platforms/powernv/pci.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

Comments

Benjamin Herrenschmidt Sept. 7, 2012, 7:59 a.m. UTC | #1 
On Fri, 2012-09-07 at 14:45 +0800, Wei Yongjun wrote:
> From: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
> 
> The dereference should be moved below the NULL test.
> 
> spatch with a semantic match is used to found this.
> (http://coccinelle.lip6.fr/)

I haven't applied this patch yet (there was a similar one recently from
another semantic checker I believe) because that code is about to be
deeply reworked (waiting for some dependencies to get in), so this will
just make the patch harder to apply, and the stuff should never be NULL
in the first place anyway.

So let's leave that aside for a bit.

Cheers,
Ben.

> Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
> ---
>  arch/powerpc/platforms/powernv/pci.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c
> index be3cfc5..4ba89c1 100644
> --- a/arch/powerpc/platforms/powernv/pci.c
> +++ b/arch/powerpc/platforms/powernv/pci.c
> @@ -287,13 +287,15 @@ static int pnv_pci_read_config(struct pci_bus *bus,
>  			       int where, int size, u32 *val)
>  {
>  	struct pci_controller *hose = pci_bus_to_host(bus);
> -	struct pnv_phb *phb = hose->private_data;
> +	struct pnv_phb *phb;
>  	u32 bdfn = (((uint64_t)bus->number) << 8) | devfn;
>  	s64 rc;
>  
>  	if (hose == NULL)
>  		return PCIBIOS_DEVICE_NOT_FOUND;
>  
> +	phb = hose->private_data;
> +
>  	switch (size) {
>  	case 1: {
>  		u8 v8;
> @@ -331,12 +333,14 @@ static int pnv_pci_write_config(struct pci_bus *bus,
>  				int where, int size, u32 val)
>  {
>  	struct pci_controller *hose = pci_bus_to_host(bus);
> -	struct pnv_phb *phb = hose->private_data;
> +	struct pnv_phb *phb;
>  	u32 bdfn = (((uint64_t)bus->number) << 8) | devfn;
>  
>  	if (hose == NULL)
>  		return PCIBIOS_DEVICE_NOT_FOUND;
>  
> +	phb = hose->private_data;
> +
>  	cfg_dbg("pnv_pci_write_config bus: %x devfn: %x +%x/%x -> %08x\n",
>  		bus->number, devfn, where, size, val);
>  	switch (size) {
diff mbox

Patch

diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c
index be3cfc5..4ba89c1 100644
--- a/arch/powerpc/platforms/powernv/pci.c
+++ b/arch/powerpc/platforms/powernv/pci.c
@@ -287,13 +287,15 @@  static int pnv_pci_read_config(struct pci_bus *bus,
 			       int where, int size, u32 *val)
 {
 	struct pci_controller *hose = pci_bus_to_host(bus);
-	struct pnv_phb *phb = hose->private_data;
+	struct pnv_phb *phb;
 	u32 bdfn = (((uint64_t)bus->number) << 8) | devfn;
 	s64 rc;
 
 	if (hose == NULL)
 		return PCIBIOS_DEVICE_NOT_FOUND;
 
+	phb = hose->private_data;
+
 	switch (size) {
 	case 1: {
 		u8 v8;
@@ -331,12 +333,14 @@  static int pnv_pci_write_config(struct pci_bus *bus,
 				int where, int size, u32 val)
 {
 	struct pci_controller *hose = pci_bus_to_host(bus);
-	struct pnv_phb *phb = hose->private_data;
+	struct pnv_phb *phb;
 	u32 bdfn = (((uint64_t)bus->number) << 8) | devfn;
 
 	if (hose == NULL)
 		return PCIBIOS_DEVICE_NOT_FOUND;
 
+	phb = hose->private_data;
+
 	cfg_dbg("pnv_pci_write_config bus: %x devfn: %x +%x/%x -> %08x\n",
 		bus->number, devfn, where, size, val);
 	switch (size) {