Re: [PATCH] lib/scatterlist: Avoid a double memset

From: Joe Perches
Date: Sun Sep 20 2020 - 03:28:47 EST

On Sun, 2020-09-20 at 09:15 +0200, Christophe JAILLET wrote:
> 'sgl' is zeroed a few lines below in 'sg_init_table()'. There is no need to
> clear it twice.
> Remove the redundant initialization.

I didn't look very thoroughly, but there are at least
a few more of these with kcalloc and kzalloc like

block/bsg-lib.c- size_t sz = (sizeof(struct scatterlist) * req->nr_phys_segments);
block/bsg-lib.c- BUG_ON(!req->nr_phys_segments);
block/bsg-lib.c- buf->sg_list = kzalloc(sz, GFP_KERNEL);
block/bsg-lib.c- if (!buf->sg_list)
block/bsg-lib.c- return -ENOMEM;
block/bsg-lib.c: sg_init_table(buf->sg_list, req->nr_phys_segments);
drivers/target/target_core_rd.c- sg = kcalloc(sg_per_table + chain_entry, sizeof(*sg),
drivers/target/target_core_rd.c- GFP_KERNEL);
drivers/target/target_core_rd.c- if (!sg)
drivers/target/target_core_rd.c- return -ENOMEM;
drivers/target/target_core_rd.c: sg_init_table(sg, sg_per_table + chain_entry);
net/rds/rdma.c- sg = kcalloc(nents, sizeof(*sg), GFP_KERNEL);
net/rds/rdma.c- if (!sg) {
net/rds/rdma.c- ret = -ENOMEM;
net/rds/rdma.c- goto out;
net/rds/rdma.c- }
net/rds/rdma.c- WARN_ON(!nents);
net/rds/rdma.c: sg_init_table(sg, nents);