From: Yousong Zhou <yszhou4tech@gmail.com>
Date: Fri, 13 Jan 2017 17:00:35 +0000 (+0800)
Subject: kmodloader: make insert_module() idempotent
X-Git-Url: http://git.archive.openwrt.org/?p=project%2Fubox.git;a=commitdiff_plain;h=14839f0acc15197e360299b7f714b8f9ff97ba17

kmodloader: make insert_module() idempotent

To fix spurious error messages in the following situation

 1. scan loaded modules
 2. load wireguard.ko and the module itself will request xt_hashlimit to
    be loaded
 3. xt_hashlimit is still in PROBE state here so we also try to load it,
    but init_module() returns EEXIST

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>
---

diff --git a/kmodloader.c b/kmodloader.c
index bcb213b..729027a 100644
--- a/kmodloader.c
+++ b/kmodloader.c
@@ -574,8 +574,11 @@ static int insert_module(char *path, const char *options)
 	}
 
 	data = malloc(s.st_size);
-	if (read(fd, data, s.st_size) == s.st_size)
+	if (read(fd, data, s.st_size) == s.st_size) {
 		ret = syscall(__NR_init_module, data, (unsigned long) s.st_size, options);
+		if (errno == EEXIST)
+			ret = 0;
+	}
 	else
 		ULOG_ERR("failed to read full module %s\n", path);