diff mbox series

[3/4] um: port_user: Improve error handling when port-helper is not found

Message ID e17d38020164bfd224f35e57ebcc83748f399ca7.1646292328.git.development@efficientek.com
State Accepted
Headers show
Series [1/4] um: port_user: Search for in.telnetd in PATH | expand

Commit Message

Glenn Washburn March 3, 2022, 7:53 a.m. UTC 
Check if port-helper exists and is executable. If not, write an error
message to the kernel log with information to help the user diagnose the
issue and exit with an error. If UML_PORT_HELPER was not set, write a
message suggesting that the user set it. This makes it easier to understand
why telneting to the UML instance is failing and what can be done to fix it.

Signed-off-by: Glenn Washburn <development@efficientek.com>
---
 arch/um/drivers/port_user.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)
diff mbox series

Patch

diff --git a/arch/um/drivers/port_user.c b/arch/um/drivers/port_user.c
index 3e32351dadad..3c62ae81df62 100644
--- a/arch/um/drivers/port_user.c
+++ b/arch/um/drivers/port_user.c
@@ -5,6 +5,7 @@ 
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <errno.h>
 #include <termios.h>
 #include <unistd.h>
@@ -179,6 +180,17 @@  int port_connection(int fd, int *socket, int *pid_out)
 	if (new < 0)
 		return -errno;
 
+	err = os_access(argv[2], X_OK);
+	if (err < 0) {
+		printk(UM_KERN_ERR "port_connection : error accessing port-helper "
+		       "executable at %s: %s\n", argv[2], strerror(-err));
+		if (env == NULL)
+			printk(UM_KERN_ERR "Set UML_PORT_HELPER environment "
+				"variable to path to uml-utilities port-helper "
+				"binary\n");
+		goto out_close;
+	}
+
 	err = os_pipe(socket, 0, 0);
 	if (err < 0)
 		goto out_close;