lib/netconsole: fix wrpc hangs during reboot of a switch

During reboot of a switch, WRPC tries to print messages like: Warning: tx not terminated infinite mcr=0x1001500 Warning: tx timestamp never became available Warning: tx timestamp never became available Warning: tx not terminated infinite mcr=0x1001500 Warning: tx timestamp never became available Warning: tx timestamp never became available Warning: tx timestamp never became available The pp_printf in network functions caused netconsole_write_string to be called recursively. This caused hangs of wrpc. Signed-off-by: Adam Wujek <adam.wujek@cern.ch>

lib/netconsole: fix wrpc hangs during reboot of a switch
During reboot of a switch, WRPC tries to print messages like: Warning: tx not terminated infinite mcr=0x1001500 Warning: tx timestamp never became available Warning: tx timestamp never became available Warning: tx not terminated infinite mcr=0x1001500 Warning: tx timestamp never became available Warning: tx timestamp never became available Warning: tx timestamp never became available The pp_printf in network functions caused netconsole_write_string to be called recursively. This caused hangs of wrpc. Signed-off-by: Adam Wujek <adam.wujek@cern.ch>
043efb0d · Adam Wujek · 5de57d52 · 043efb0d
Commit 043efb0d authored Nov 06, 2018 by Adam Wujek 💬
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Showing with 8 additions and 4 deletions

netconsole.c lib/netconsole.c +8 -4

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--- a/lib/netconsole.c
+++ b/lib/netconsole.c
@@ -52,14 +52,19 @@ int netconsole_write_string(const char *s)
 	static int len = 0;
 	const uint8_t *p;
 	static uint8_t *d = NULL;
+	static int rec_level = 0;

 	if (netconsole_status != NETCONSOLE_ENABLED)
 		return 0;
+
 	/* Prevent recursive calls when net verbose configured.
 	 * NOTE: Even with the following if, NET_IS_VERBOSE does not work
 	 * with netconsole */
-	if (NET_IS_VERBOSE)
-		netconsole_status = NETCONSOLE_DISABLED;
+	if (rec_level > 0)
+		return 0;
+
+	rec_level++;
+	
 	p = (uint8_t *)s;
 	while (1) {
 		if (!d) {
@@ -94,8 +99,7 @@ int netconsole_write_string(const char *s)
 		d++;
 	}

-	if (NET_IS_VERBOSE)
-		netconsole_status = NETCONSOLE_ENABLED;
+	rec_level--;
 	return 0;
 }