[PATCH v2 4/4] sunrpc: sysctl: replace simple_strtol with kstrtouint

[Eric-Terminal <ericterminal@gmail.com>]

From: Yufan Chen <ericterminal@gmail.com>

Use kstrtouint() in proc_dodebug() after trimming trailing
whitespace. This keeps accepted whitespace behavior while enforcing
full-token parsing with standard errno returns.

Signed-off-by: Yufan Chen <ericterminal@gmail.com>
---
 net/sunrpc/sysctl.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/net/sunrpc/sysctl.c b/net/sunrpc/sysctl.c
index bdb587a72..07072218b 100644
--- a/net/sunrpc/sysctl.c
+++ b/net/sunrpc/sysctl.c
@@ -12,6 +12,7 @@
 #include <linux/linkage.h>
 #include <linux/ctype.h>
 #include <linux/fs.h>
+#include <linux/kernel.h>
 #include <linux/sysctl.h>
 #include <linux/module.h>
 
@@ -65,10 +66,11 @@ static int
 proc_dodebug(const struct ctl_table *table, int write, void *buffer, size_t *lenp,
 	     loff_t *ppos)
 {
-	char		tmpbuf[20], *s = NULL;
+	char		tmpbuf[20];
 	char *p;
 	unsigned int	value;
 	size_t		left, len;
+	int		ret;
 
 	if ((*ppos && !write) || !*lenp) {
 		*lenp = 0;
@@ -89,19 +91,17 @@ proc_dodebug(const struct ctl_table *table, int write, void *buffer, size_t *len
 		if (left > sizeof(tmpbuf) - 1)
 			return -EINVAL;
 		memcpy(tmpbuf, p, left);
+
+		while (left && isspace(tmpbuf[left - 1]))
+			left--;
 		tmpbuf[left] = '\0';
+		if (!tmpbuf[0])
+			goto done;
 
-		value = simple_strtol(tmpbuf, &s, 0);
-		if (s) {
-			left -= (s - tmpbuf);
-			if (left && !isspace(*s))
-				return -EINVAL;
-			while (left && isspace(*s)) {
-				left--;
-				s++;
-			}
-		} else
-			left = 0;
+		ret = kstrtouint(tmpbuf, 0, &value);
+		if (ret)
+			return ret;
+		left = 0;
 		*(unsigned int *) table->data = value;
 		/* Display the RPC tasks on writing to rpc_debug */
 		if (strcmp(table->procname, "rpc_debug") == 0)
-- 
2.47.3