| Message ID | 20180824010706.GA25522@embeddedor.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | memory: atmel-ebi: Use struct_size() in devm_kzalloc() | expand |
On Thu, Aug 23, 2018 at 6:07 PM, Gustavo A. R. Silva <gustavo@embeddedor.com> 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 = devm_kzalloc(dev, 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 = devm_kzalloc(dev, struct_size(instance, entry, count), GFP_KERNEL); > > This issue was detected with the help of Coccinelle. > > Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Reviewed-by: Kees Cook <keescook@chromium.org> -Kees > --- > drivers/memory/atmel-ebi.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/memory/atmel-ebi.c b/drivers/memory/atmel-ebi.c > index b907865..c3748b4 100644 > --- a/drivers/memory/atmel-ebi.c > +++ b/drivers/memory/atmel-ebi.c > @@ -327,8 +327,7 @@ static int atmel_ebi_dev_setup(struct atmel_ebi *ebi, struct device_node *np, > return -EINVAL; > } > > - ebid = devm_kzalloc(ebi->dev, > - sizeof(*ebid) + (numcs * sizeof(*ebid->configs)), > + ebid = devm_kzalloc(ebi->dev, struct_size(ebid, configs, numcs), > GFP_KERNEL); > if (!ebid) > return -ENOMEM; > -- > 2.7.4 >
On 23/08/2018 20:07:06-0500, 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 = devm_kzalloc(dev, 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 = devm_kzalloc(dev, struct_size(instance, entry, count), GFP_KERNEL); > > This issue was detected with the help of Coccinelle. > > Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> > --- > drivers/memory/atmel-ebi.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > Applied, thanks.
diff --git a/drivers/memory/atmel-ebi.c b/drivers/memory/atmel-ebi.c index b907865..c3748b4 100644 --- a/drivers/memory/atmel-ebi.c +++ b/drivers/memory/atmel-ebi.c @@ -327,8 +327,7 @@ static int atmel_ebi_dev_setup(struct atmel_ebi *ebi, struct device_node *np, return -EINVAL; } - ebid = devm_kzalloc(ebi->dev, - sizeof(*ebid) + (numcs * sizeof(*ebid->configs)), + ebid = devm_kzalloc(ebi->dev, struct_size(ebid, configs, numcs), GFP_KERNEL); if (!ebid) return -ENOMEM;
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 = devm_kzalloc(dev, 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 = devm_kzalloc(dev, struct_size(instance, entry, count), GFP_KERNEL); This issue was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> --- drivers/memory/atmel-ebi.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)