| Message ID | 20190131010015.GA32272@embeddedor (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/vc4: Use struct_size() in kzalloc() | expand |
"Gustavo A. R. Silva" <gustavo@embeddedor.com> writes: > 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) + count * sizeof(struct boo), 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> Reviewed and pushed to drm-misc-next. Thanks!
On 2/7/19 4:59 PM, Eric Anholt wrote: > "Gustavo A. R. Silva" <gustavo@embeddedor.com> writes: > >> 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) + count * sizeof(struct boo), 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> > > Reviewed and pushed to drm-misc-next. Thanks! > Thank you, Eric. -- Gustavo
diff --git a/drivers/gpu/drm/vc4/vc4_perfmon.c b/drivers/gpu/drm/vc4/vc4_perfmon.c index 437e7a27f21d..495150415020 100644 --- a/drivers/gpu/drm/vc4/vc4_perfmon.c +++ b/drivers/gpu/drm/vc4/vc4_perfmon.c @@ -117,7 +117,7 @@ int vc4_perfmon_create_ioctl(struct drm_device *dev, void *data, return -EINVAL; } - perfmon = kzalloc(sizeof(*perfmon) + (req->ncounters * sizeof(u64)), + perfmon = kzalloc(struct_size(perfmon, counters, req->ncounters), GFP_KERNEL); if (!perfmon) 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 = kzalloc(sizeof(struct foo) + count * sizeof(struct boo), 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/gpu/drm/vc4/vc4_perfmon.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)