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Subject[PATCH 2/2] SUNRPC: Optimize 'svc_print_xprts()'
Date
Using 'snprintf' is safer than 'sprintf' because it can avoid a buffer
overflow.
The return value can also be used to avoid a strlen a call.

Finally, we know where we need to copy and the length to copy, so, we
can save a few cycles by rearraging the code and using a memcpy instead of
a strcat.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
This patch should have no functionnal change.
We could go further, use scnprintf and write directly in the destination
buffer. However, this could lead to a truncated last line.
---
net/sunrpc/svc_xprt.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index df39e7b8b06c..6df861650040 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -118,12 +118,12 @@ int svc_print_xprts(char *buf, int maxlen)
list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) {
int slen;

- sprintf(tmpstr, "%s %d\n", xcl->xcl_name, xcl->xcl_max_payload);
- slen = strlen(tmpstr);
- if (len + slen >= maxlen)
+ slen = snprintf(tmpstr, sizeof(tmpstr), "%s %d\n",
+ xcl->xcl_name, xcl->xcl_max_payload);
+ if (slen >= sizeof(tmpstr) || len + slen >= maxlen)
break;
+ memcpy(buf + len, tmpstr, slen + 1);
len += slen;
- strcat(buf, tmpstr);
}
spin_unlock(&svc_xprt_class_lock);

--
2.20.1
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