net/rds: Use ERR_PTR for rds_message_alloc_sgs()

commit 7dba92037baf3fa00b4880a31fd532542264994c upstream.

Returning the error code via a 'int *ret' when the function returns a
pointer is very un-kernely and causes gcc 10's static analysis to choke:

net/rds/message.c: In function ‘rds_message_map_pages’:
net/rds/message.c:358:10: warning: ‘ret’ may be used uninitialized in this function [-Wmaybe-uninitialized]
  358 |   return ERR_PTR(ret);

Use a typical ERR_PTR return instead.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/rds/message.c b/net/rds/message.c
index 50f13f1..2d43e13 100644 (file)
--- a/net/rds/message.c
+++ b/net/rds/message.c
@@ -308,26 +308,20 @@ out:
 /*
  * RDS ops use this to grab SG entries from the rm's sg pool.
  */
-struct scatterlist *rds_message_alloc_sgs(struct rds_message *rm, int nents,
-                                         int *ret)
+struct scatterlist *rds_message_alloc_sgs(struct rds_message *rm, int nents)
 {
        struct scatterlist *sg_first = (struct scatterlist *) &rm[1];
        struct scatterlist *sg_ret;
 
-       if (WARN_ON(!ret))
-               return NULL;
-
        if (nents <= 0) {
                pr_warn("rds: alloc sgs failed! nents <= 0\n");
-               *ret = -EINVAL;
-               return NULL;
+               return ERR_PTR(-EINVAL);
        }
 
        if (rm->m_used_sgs + nents > rm->m_total_sgs) {
                pr_warn("rds: alloc sgs failed! total %d used %d nents %d\n",
                        rm->m_total_sgs, rm->m_used_sgs, nents);
-               *ret = -ENOMEM;
-               return NULL;
+               return ERR_PTR(-ENOMEM);
        }
 
        sg_ret = &sg_first[rm->m_used_sgs];
@@ -343,7 +337,6 @@ struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned in
        unsigned int i;
        int num_sgs = DIV_ROUND_UP(total_len, PAGE_SIZE);
        int extra_bytes = num_sgs * sizeof(struct scatterlist);
-       int ret;
 
        rm = rds_message_alloc(extra_bytes, GFP_NOWAIT);
        if (!rm)
@@ -352,10 +345,10 @@ struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned in
        set_bit(RDS_MSG_PAGEVEC, &rm->m_flags);
        rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
        rm->data.op_nents = DIV_ROUND_UP(total_len, PAGE_SIZE);
-       rm->data.op_sg = rds_message_alloc_sgs(rm, num_sgs, &ret);
-       if (!rm->data.op_sg) {
+       rm->data.op_sg = rds_message_alloc_sgs(rm, num_sgs);
+       if (IS_ERR(rm->data.op_sg)) {
                rds_message_put(rm);
-               return ERR_PTR(ret);
+               return ERR_CAST(rm->data.op_sg);
        }
 
        for (i = 0; i < rm->data.op_nents; ++i) {

diff --git a/net/rds/rdma.c b/net/rds/rdma.c
index 916f5ec..8e10f95 100644 (file)
--- a/net/rds/rdma.c
+++ b/net/rds/rdma.c
@@ -624,9 +624,11 @@ int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm,
        op->op_active = 1;
        op->op_recverr = rs->rs_recverr;
        WARN_ON(!nr_pages);
-       op->op_sg = rds_message_alloc_sgs(rm, nr_pages, &ret);
-       if (!op->op_sg)
+       op->op_sg = rds_message_alloc_sgs(rm, nr_pages);
+       if (IS_ERR(op->op_sg)) {
+               ret = PTR_ERR(op->op_sg);
                goto out_pages;
+       }
 
        if (op->op_notify || op->op_recverr) {
                /* We allocate an uninitialized notifier here, because
@@ -828,9 +830,11 @@ int rds_cmsg_atomic(struct rds_sock *rs, struct rds_message *rm,
        rm->atomic.op_silent = !!(args->flags & RDS_RDMA_SILENT);
        rm->atomic.op_active = 1;
        rm->atomic.op_recverr = rs->rs_recverr;
-       rm->atomic.op_sg = rds_message_alloc_sgs(rm, 1, &ret);
-       if (!rm->atomic.op_sg)
+       rm->atomic.op_sg = rds_message_alloc_sgs(rm, 1);
+       if (IS_ERR(rm->atomic.op_sg)) {
+               ret = PTR_ERR(rm->atomic.op_sg);
                goto err;
+       }
 
        /* verify 8 byte-aligned */
        if (args->local_addr & 0x7) {

diff --git a/net/rds/rds.h b/net/rds/rds.h
index 53e8691..2ac5b5e 100644 (file)
--- a/net/rds/rds.h
+++ b/net/rds/rds.h
@@ -849,8 +849,7 @@ rds_conn_connecting(struct rds_connection *conn)
 
 /* message.c */
 struct rds_message *rds_message_alloc(unsigned int nents, gfp_t gfp);
-struct scatterlist *rds_message_alloc_sgs(struct rds_message *rm, int nents,
-                                         int *ret);
+struct scatterlist *rds_message_alloc_sgs(struct rds_message *rm, int nents);
 int rds_message_copy_from_user(struct rds_message *rm, struct iov_iter *from,
                               bool zcopy);
 struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned int total_len);

diff --git a/net/rds/send.c b/net/rds/send.c
index 82dcd8b..68e2bdb 100644 (file)
--- a/net/rds/send.c
+++ b/net/rds/send.c
@@ -1274,9 +1274,11 @@ int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len)
 
        /* Attach data to the rm */
        if (payload_len) {
-               rm->data.op_sg = rds_message_alloc_sgs(rm, num_sgs, &ret);
-               if (!rm->data.op_sg)
+               rm->data.op_sg = rds_message_alloc_sgs(rm, num_sgs);
+               if (IS_ERR(rm->data.op_sg)) {
+                       ret = PTR_ERR(rm->data.op_sg);
                        goto out;
+               }
                ret = rds_message_copy_from_user(rm, &msg->msg_iter, zcopy);
                if (ret)
                        goto out;