| Message ID | 20180824011753.GA25826@embeddedor.com (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Delegated to: | Andy Gross |
| Headers | show |
| Series | drivers: qcom: rpmh: use struct_size() in kzalloc() | expand |
On Thu, Aug 23, 2018 at 6:17 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 = kzalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_ATOMIC); > > 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_ATOMIC); > > 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/soc/qcom/rpmh.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/soc/qcom/rpmh.c b/drivers/soc/qcom/rpmh.c > index c7beb68..12c057a 100644 > --- a/drivers/soc/qcom/rpmh.c > +++ b/drivers/soc/qcom/rpmh.c > @@ -362,8 +362,7 @@ int rpmh_write_batch(const struct device *dev, enum rpmh_state state, > if (!count) > return -EINVAL; > > - req = kzalloc(sizeof(*req) + count * sizeof(req->rpm_msgs[0]), > - GFP_ATOMIC); > + req = kzalloc(struct_size(req, rpm_msgs, count), GFP_ATOMIC); > if (!req) > return -ENOMEM; > req->count = count; > -- > 2.7.4 >
On Thu 23 Aug 18:17 PDT 2018, 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_ATOMIC); > > 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_ATOMIC); > > This issue was detected with the help of Coccinelle. > > Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Regards, Bjorn > --- > drivers/soc/qcom/rpmh.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/soc/qcom/rpmh.c b/drivers/soc/qcom/rpmh.c > index c7beb68..12c057a 100644 > --- a/drivers/soc/qcom/rpmh.c > +++ b/drivers/soc/qcom/rpmh.c > @@ -362,8 +362,7 @@ int rpmh_write_batch(const struct device *dev, enum rpmh_state state, > if (!count) > return -EINVAL; > > - req = kzalloc(sizeof(*req) + count * sizeof(req->rpm_msgs[0]), > - GFP_ATOMIC); > + req = kzalloc(struct_size(req, rpm_msgs, count), GFP_ATOMIC); > if (!req) > return -ENOMEM; > req->count = count; > -- > 2.7.4 >
diff --git a/drivers/soc/qcom/rpmh.c b/drivers/soc/qcom/rpmh.c index c7beb68..12c057a 100644 --- a/drivers/soc/qcom/rpmh.c +++ b/drivers/soc/qcom/rpmh.c @@ -362,8 +362,7 @@ int rpmh_write_batch(const struct device *dev, enum rpmh_state state, if (!count) return -EINVAL; - req = kzalloc(sizeof(*req) + count * sizeof(req->rpm_msgs[0]), - GFP_ATOMIC); + req = kzalloc(struct_size(req, rpm_msgs, count), GFP_ATOMIC); if (!req) return -ENOMEM; req->count = count;
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_ATOMIC); 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_ATOMIC); This issue was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> --- drivers/soc/qcom/rpmh.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)