Messages in this thread | | | Date | Fri, 8 Mar 2019 14:27:27 +0100 | From | Christoph Hellwig <> | Subject | Re: [PATCH] nvmet-fc: use zero-sized array and struct_size() in kzalloc() |
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James, can you take a look at this one?
On Sat, Feb 23, 2019 at 12:51:08PM -0600, Gustavo A. R. Silva wrote: > Update the code to use a zero-sized array instead of a pointer in > structure nvmet_fc_tgt_queue and use struct_size() in kzalloc(). > > Notice that 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; > struct boo entry[]; > }; > > instance = kzalloc(sizeof(struct foo) + sizeof(struct boo) * 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/nvme/target/fc.c | 7 ++----- > 1 file changed, 2 insertions(+), 5 deletions(-) > > diff --git a/drivers/nvme/target/fc.c b/drivers/nvme/target/fc.c > index 1e9654f04c60..23baec38f97e 100644 > --- a/drivers/nvme/target/fc.c > +++ b/drivers/nvme/target/fc.c > @@ -128,12 +128,12 @@ struct nvmet_fc_tgt_queue { > struct nvmet_cq nvme_cq; > struct nvmet_sq nvme_sq; > struct nvmet_fc_tgt_assoc *assoc; > - struct nvmet_fc_fcp_iod *fod; /* array of fcp_iods */ > struct list_head fod_list; > struct list_head pending_cmd_list; > struct list_head avail_defer_list; > struct workqueue_struct *work_q; > struct kref ref; > + struct nvmet_fc_fcp_iod fod[]; /* array of fcp_iods */ > } __aligned(sizeof(unsigned long long)); > > struct nvmet_fc_tgt_assoc { > @@ -588,9 +588,7 @@ nvmet_fc_alloc_target_queue(struct nvmet_fc_tgt_assoc *assoc, > if (qid > NVMET_NR_QUEUES) > return NULL; > > - queue = kzalloc((sizeof(*queue) + > - (sizeof(struct nvmet_fc_fcp_iod) * sqsize)), > - GFP_KERNEL); > + queue = kzalloc(struct_size(queue, fod, sqsize), GFP_KERNEL); > if (!queue) > return NULL; > > @@ -603,7 +601,6 @@ nvmet_fc_alloc_target_queue(struct nvmet_fc_tgt_assoc *assoc, > if (!queue->work_q) > goto out_a_put; > > - queue->fod = (struct nvmet_fc_fcp_iod *)&queue[1]; > queue->qid = qid; > queue->sqsize = sqsize; > queue->assoc = assoc; > -- > 2.20.1 ---end quoted text---
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