uml: fix infinite mconsole loop

This patch takes care of a problem with the stopping code.

The function inside the while condition returns 0 to signify a problem.  A
problem could be for example a bad command or a bad version of the mconsole
client.  A bad command would terminate the stopping loop and resume the
kernel.  This is a problem.

A better solution is to make the loop infinite and don't leave it until we are
explicitly told to.

Signed-off-by: Karol Swietlicki <magotari@gmail.com>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 1 deletions

diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index c953e1477be4..949037e92a7b 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -305,7 +305,9 @@ void mconsole_stop(struct mc_request *req)
         deactivate_fd(req->originating_fd, MCONSOLE_IRQ);
         os_set_fd_block(req->originating_fd, 1);
         mconsole_reply(req, "stopped", 0, 0);
-        while (mconsole_get_request(req->originating_fd, req)) {
+        for (;;) {
+                if (!mconsole_get_request(req->originating_fd, req))
+                        continue;
                 if (req->cmd->handler == mconsole_go)
                         break;
                 if (req->cmd->handler == mconsole_stop) {