This is a note to let you know that I've just added the patch titled
um: port_user: Improve error handling when port-helper is not found
to the 5.17-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
um-port_user-improve-error-handling-when-port-helper.patch
and it can be found in the queue-5.17 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit efc324ad7e7e1c92a8862bd71b2f5f8f15513304
Author: Glenn Washburn <development@xxxxxxxxxxxxxxx>
Date: Thu Mar 3 01:53:32 2022 -0600
um: port_user: Improve error handling when port-helper is not found
[ Upstream commit 3cb5a7f167c620a8b0e38b0446df2e024d2243dc ]
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@xxxxxxxxxxxxxxx>
Signed-off-by: Richard Weinberger <richard@xxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/um/drivers/port_user.c b/arch/um/drivers/port_user.c
index 5b5b64cb1071..133ca7bf2d91 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>
@@ -175,6 +176,17 @@ 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;
