| Message ID | 20190104212545.GA16927@embeddedor (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | dmaengine: fsl-edma: use struct_size() in kzalloc() | expand |
On Fri, Jan 04, 2019 at 03:25:45PM -0600, Gustavo A. R. Silva wrote: > One of the more common cases of allocation size calculations is finding the > size of a structure that has a zero-sized array at the end, along with memory > for some number of elements for that array. For example: > > struct foo { > int stuff; > void *entry[]; > }; > > instance = kzalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL); > > Instead of leaving these open-coded and prone to type mistakes, we can now > use the new struct_size() helper: > > instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL); > > This code was detected with the help of Coccinelle. > > Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> > --- > drivers/dma/fsl-edma-common.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/drivers/dma/fsl-edma-common.c b/drivers/dma/fsl-edma-common.c > index 8876c4c1bb2c..fe529100674f 100644 > --- a/drivers/dma/fsl-edma-common.c > +++ b/drivers/dma/fsl-edma-common.c > @@ -339,9 +339,7 @@ static struct fsl_edma_desc *fsl_edma_alloc_desc(struct fsl_edma_chan *fsl_chan, > struct fsl_edma_desc *fsl_desc; > int i; > > - fsl_desc = kzalloc(sizeof(*fsl_desc) + > - sizeof(struct fsl_edma_sw_tcd) * > - sg_len, GFP_NOWAIT); > + fsl_desc = kzalloc(struct_size(fsl_desc, tcd, sg_len), GFP_NOWAIT); > if (!fsl_desc) > return NULL; > Tested-by: Angelo Dureghello <angelo@sysam.it> > -- > 2.20.1 >
On 1/6/19 1:40 PM, Angelo Dureghello wrote: > On Fri, Jan 04, 2019 at 03:25:45PM -0600, Gustavo A. R. Silva wrote: >> One of the more common cases of allocation size calculations is finding the >> size of a structure that has a zero-sized array at the end, along with memory >> for some number of elements for that array. For example: >> >> struct foo { >> int stuff; >> void *entry[]; >> }; >> >> instance = kzalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL); >> >> Instead of leaving these open-coded and prone to type mistakes, we can now >> use the new struct_size() helper: >> >> instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL); >> >> This code was detected with the help of Coccinelle. >> >> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> >> --- >> drivers/dma/fsl-edma-common.c | 4 +--- >> 1 file changed, 1 insertion(+), 3 deletions(-) >> >> diff --git a/drivers/dma/fsl-edma-common.c b/drivers/dma/fsl-edma-common.c >> index 8876c4c1bb2c..fe529100674f 100644 >> --- a/drivers/dma/fsl-edma-common.c >> +++ b/drivers/dma/fsl-edma-common.c >> @@ -339,9 +339,7 @@ static struct fsl_edma_desc *fsl_edma_alloc_desc(struct fsl_edma_chan *fsl_chan, >> struct fsl_edma_desc *fsl_desc; >> int i; >> >> - fsl_desc = kzalloc(sizeof(*fsl_desc) + >> - sizeof(struct fsl_edma_sw_tcd) * >> - sg_len, GFP_NOWAIT); >> + fsl_desc = kzalloc(struct_size(fsl_desc, tcd, sg_len), GFP_NOWAIT); >> if (!fsl_desc) >> return NULL; >> > > Tested-by: Angelo Dureghello <angelo@sysam.it> > Thanks, Angelo. -- Gustavo
On 04-01-19, 15:25, Gustavo A. R. Silva wrote: > One of the more common cases of allocation size calculations is finding the > size of a structure that has a zero-sized array at the end, along with memory > for some number of elements for that array. For example: > > struct foo { > int stuff; > void *entry[]; > }; > > instance = kzalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL); > > Instead of leaving these open-coded and prone to type mistakes, we can now > use the new struct_size() helper: > > instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL); > > This code was detected with the help of Coccinelle. Applied, thanks
diff --git a/drivers/dma/fsl-edma-common.c b/drivers/dma/fsl-edma-common.c index 8876c4c1bb2c..fe529100674f 100644 --- a/drivers/dma/fsl-edma-common.c +++ b/drivers/dma/fsl-edma-common.c @@ -339,9 +339,7 @@ static struct fsl_edma_desc *fsl_edma_alloc_desc(struct fsl_edma_chan *fsl_chan, struct fsl_edma_desc *fsl_desc; int i; - fsl_desc = kzalloc(sizeof(*fsl_desc) + - sizeof(struct fsl_edma_sw_tcd) * - sg_len, GFP_NOWAIT); + fsl_desc = kzalloc(struct_size(fsl_desc, tcd, sg_len), GFP_NOWAIT); if (!fsl_desc) return NULL;
One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example: struct foo { int stuff; void *entry[]; }; instance = kzalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL); Instead of leaving these open-coded and prone to type mistakes, we can now use the new struct_size() helper: instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL); This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> --- drivers/dma/fsl-edma-common.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)