dropreason: suppress error msg in drop_reason_support()

menglongdong · menglongdong · commit 27f30d2b6573 · 2023-03-15T14:35:58.000+08:00
Signed-off-by: Menglong Dong &lt;imagedong@tencent.com&gt;
diff --git a/src/dropreason.c b/src/dropreason.c
@@ -18,7 +18,8 @@ static bool drop_reason_inited = false;
 bool drop_reason_support()
 {
 	return simple_exec("cat /sys/kernel/debug/tracing/events/skb/"
-			   "kfree_skb/format | grep NOT_SPECIFIED") == 0;
+			   "kfree_skb/format 2>/dev/null | "
+			   "grep NOT_SPECIFIED") == 0;
 }
 
 static int parse_reason_enum()

Original file line number	Diff line number	Diff line change
`@@ -18,7 +18,8 @@ static bool drop_reason_inited = false;`
`18`	`18`	`bool drop_reason_support()`
`19`	`19`	`{`
`20`	`20`	`return simple_exec("cat /sys/kernel/debug/tracing/events/skb/"`
`21`		`- "kfree_skb/format \| grep NOT_SPECIFIED") == 0;`
	`21`	`+ "kfree_skb/format 2>/dev/null \| "`
	`22`	`+ "grep NOT_SPECIFIED") == 0;`
`22`	`23`	`}`
`23`	`24`
`24`	`25`	`static int parse_reason_enum()`