[dpdk-dev] [PATCH v2] eal: save error in string copy

[Xueming Li <xuemingl@nvidia.com>]

From: Thomas Monjalon <thomas@monjalon.net>

The string copy api rte_strscpy() doesn't set rte_errno during failures,
instead it just return negative error number.

Sets rte_errrno if the destination buffer is too small.

Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
Signed-off-by: Xueming Li <xuemingl@nvidia.com>
---
 lib/eal/common/eal_common_string_fns.c |  4 +++-
 lib/eal/common/eal_common_trace.c      |  1 -
 lib/eal/include/rte_string_fns.h       |  5 ++---
 lib/graph/node.c                       | 12 +++---------
 4 files changed, 8 insertions(+), 14 deletions(-)

diff --git a/lib/eal/common/eal_common_string_fns.c b/lib/eal/common/eal_common_string_fns.c
index 60c5dd66f9..ddd1891656 100644
--- a/lib/eal/common/eal_common_string_fns.c
+++ b/lib/eal/common/eal_common_string_fns.c
@@ -8,6 +8,7 @@
 #include <errno.h>
 
 #include <rte_string_fns.h>
+#include <rte_errno.h>
 
 /* split string into tokens */
 int
@@ -62,5 +63,6 @@ rte_strscpy(char *dst, const char *src, size_t dsize)
 	/* Not enough room in dst, set NUL and return error. */
 	if (res != 0)
 		dst[res - 1] = '\0';
-	return -E2BIG;
+	rte_errno = E2BIG;
+	return -rte_errno;
 }
diff --git a/lib/eal/common/eal_common_trace.c b/lib/eal/common/eal_common_trace.c
index 24e27387b1..7bff1cd2ce 100644
--- a/lib/eal/common/eal_common_trace.c
+++ b/lib/eal/common/eal_common_trace.c
@@ -500,7 +500,6 @@ __rte_trace_point_register(rte_trace_point_t *handle, const char *name,
 	/* Initialize the trace point */
 	if (rte_strscpy(tp->name, name, TRACE_POINT_NAME_SIZE) < 0) {
 		trace_err("name is too long");
-		rte_errno = E2BIG;
 		goto free;
 	}
 
diff --git a/lib/eal/include/rte_string_fns.h b/lib/eal/include/rte_string_fns.h
index 8bac8243c9..bb43b2cba3 100644
--- a/lib/eal/include/rte_string_fns.h
+++ b/lib/eal/include/rte_string_fns.h
@@ -97,8 +97,6 @@ rte_strlcat(char *dst, const char *src, size_t size)
  * Copy string src to buffer dst of size dsize.
  * At most dsize-1 chars will be copied.
  * Always NUL-terminates, unless (dsize == 0).
- * Returns number of bytes copied (terminating NUL-byte excluded) on success ;
- * negative errno on error.
  *
  * @param dst
  *   The destination string.
@@ -110,8 +108,9 @@ rte_strlcat(char *dst, const char *src, size_t size)
  *   Length in bytes of the destination buffer.
  *
  * @return
- *   The number of bytes copied on success
+ *   The number of bytes copied (terminating NUL-byte excluded) on success.
  *   -E2BIG if the destination buffer is too small.
+ *   rte_errno is set.
  */
 ssize_t
 rte_strscpy(char *dst, const char *src, size_t dsize);
diff --git a/lib/graph/node.c b/lib/graph/node.c
index 873c9ab16d..86ec4316f9 100644
--- a/lib/graph/node.c
+++ b/lib/graph/node.c
@@ -86,10 +86,8 @@ __rte_node_register(const struct rte_node_register *reg)
 	}
 
 	/* Initialize the node */
-	if (rte_strscpy(node->name, reg->name, RTE_NODE_NAMESIZE) < 0) {
-		rte_errno = E2BIG;
+	if (rte_strscpy(node->name, reg->name, RTE_NODE_NAMESIZE) < 0)
 		goto free;
-	}
 	node->flags = reg->flags;
 	node->process = reg->process;
 	node->init = reg->init;
@@ -98,10 +96,8 @@ __rte_node_register(const struct rte_node_register *reg)
 	node->parent_id = reg->parent_id;
 	for (i = 0; i < reg->nb_edges; i++) {
 		if (rte_strscpy(node->next_nodes[i], reg->next_nodes[i],
-				RTE_NODE_NAMESIZE) < 0) {
-			rte_errno = E2BIG;
+				RTE_NODE_NAMESIZE) < 0)
 			goto free;
-		}
 	}
 
 	node->id = node_id++;
@@ -278,10 +274,8 @@ edge_update(struct node *node, struct node *prev, rte_edge_t from,
 	/* Update the new nodes name */
 	for (i = from; i < max_edges; i++, count++) {
 		if (rte_strscpy(node->next_nodes[i], next_nodes[count],
-				RTE_NODE_NAMESIZE) < 0) {
-			rte_errno = E2BIG;
+				RTE_NODE_NAMESIZE) < 0)
 			goto restore;
-		}
 	}
 restore:
 	/* Update the linked list to point new node address in prev node */
-- 
2.25.1