| Message ID | 20190104184322.GA9615@embeddedor (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Commit | 55f53b9c1746bba0e1b3a8d82ff3abe7ad3b96ce |
| Headers | show |
| Series | dmaengine: st_fdma: use struct_size() in kzalloc() | expand |
Hi Gustavo On 1/4/19 7:43 PM, 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/st_fdma.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/dma/st_fdma.c b/drivers/dma/st_fdma.c > index 07c20aa2e955..df6b73028ecb 100644 > --- a/drivers/dma/st_fdma.c > +++ b/drivers/dma/st_fdma.c > @@ -243,8 +243,7 @@ static struct st_fdma_desc *st_fdma_alloc_desc(struct st_fdma_chan *fchan, > struct st_fdma_desc *fdesc; > int i; > > - fdesc = kzalloc(sizeof(*fdesc) + > - sizeof(struct st_fdma_sw_node) * sg_len, GFP_NOWAIT); > + fdesc = kzalloc(struct_size(fdesc, node, sg_len), GFP_NOWAIT); > if (!fdesc) > return NULL; > > Acked-by: Patrice Chotard <patrice.chotard@st.com> Thanks
On 1/7/19 2:50 AM, Patrice CHOTARD wrote: > Hi Gustavo > > On 1/4/19 7:43 PM, 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: >> [..] >> >> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> >> --- >> drivers/dma/st_fdma.c | 3 +-- >> 1 file changed, 1 insertion(+), 2 deletions(-) >> >> diff --git a/drivers/dma/st_fdma.c b/drivers/dma/st_fdma.c >> index 07c20aa2e955..df6b73028ecb 100644 >> --- a/drivers/dma/st_fdma.c >> +++ b/drivers/dma/st_fdma.c >> @@ -243,8 +243,7 @@ static struct st_fdma_desc *st_fdma_alloc_desc(struct st_fdma_chan *fchan, >> struct st_fdma_desc *fdesc; >> int i; >> >> - fdesc = kzalloc(sizeof(*fdesc) + >> - sizeof(struct st_fdma_sw_node) * sg_len, GFP_NOWAIT); >> + fdesc = kzalloc(struct_size(fdesc, node, sg_len), GFP_NOWAIT); >> if (!fdesc) >> return NULL; >> >> > > > Acked-by: Patrice Chotard <patrice.chotard@st.com> > Thanks, Patrice. -- Gustavo
diff --git a/drivers/dma/st_fdma.c b/drivers/dma/st_fdma.c index 07c20aa2e955..df6b73028ecb 100644 --- a/drivers/dma/st_fdma.c +++ b/drivers/dma/st_fdma.c @@ -243,8 +243,7 @@ static struct st_fdma_desc *st_fdma_alloc_desc(struct st_fdma_chan *fchan, struct st_fdma_desc *fdesc; int i; - fdesc = kzalloc(sizeof(*fdesc) + - sizeof(struct st_fdma_sw_node) * sg_len, GFP_NOWAIT); + fdesc = kzalloc(struct_size(fdesc, node, sg_len), GFP_NOWAIT); if (!fdesc) 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/st_fdma.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)