uml: DEBUG_SHIRQ fixes
DEBUG_SHIRQ generates spurious interrupts, triggering handlers such as
mconsole_interrupt() or line_interrupt(). They expect data to be available to
be read from their sockets/pipes, but in the case of spurious interrupts, the
host didn't actually send anything, so UML hangs in read() and friends.
Setting those fd's as O_NONBLOCK makes DEBUG_SHIRQ-enabled UML kernels boot
and run correctly.
Signed-off-by: Eduard-Gabriel Munteanu <maxdamage@aladin.ro>
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>
diff --git a/arch/um/drivers/chan_user.c b/arch/um/drivers/chan_user.c
index 13f0bf8..5d1289d 100644
--- a/arch/um/drivers/chan_user.c
+++ b/arch/um/drivers/chan_user.c
@@ -170,7 +170,13 @@
err = -EINVAL;
goto out_close;
}
- return err ;
+
+ if (os_set_fd_block(*fd_out, 0)) {
+ printk("winch_tramp: failed to set thread_fd non-blocking.\n");
+ goto out_close;
+ }
+
+ return err;
out_close:
os_close_file(fds[1]);
diff --git a/arch/um/drivers/mconsole_user.c b/arch/um/drivers/mconsole_user.c
index 62e5ad6..f31e715 100644
--- a/arch/um/drivers/mconsole_user.c
+++ b/arch/um/drivers/mconsole_user.c
@@ -86,8 +86,9 @@
int len;
req->originlen = sizeof(req->origin);
- req->len = recvfrom(fd, &req->request, sizeof(req->request), 0,
- (struct sockaddr *) req->origin, &req->originlen);
+ req->len = recvfrom(fd, &req->request, sizeof(req->request),
+ MSG_DONTWAIT, (struct sockaddr *) req->origin,
+ &req->originlen);
if (req->len < 0)
return 0;
diff --git a/arch/um/drivers/ubd_user.c b/arch/um/drivers/ubd_user.c
index 4707b3f..41d254b 100644
--- a/arch/um/drivers/ubd_user.c
+++ b/arch/um/drivers/ubd_user.c
@@ -43,6 +43,12 @@
kernel_fd = fds[0];
*fd_out = fds[1];
+ err = os_set_fd_block(*fd_out, 0);
+ if (err) {
+ printk("start_io_thread - failed to set nonblocking I/O.\n");
+ goto out_close;
+ }
+
pid = clone(io_thread, (void *) sp, CLONE_FILES | CLONE_VM | SIGCHLD,
NULL);
if(pid < 0){
diff --git a/arch/um/drivers/xterm.c b/arch/um/drivers/xterm.c
index 571c2b3..fe238e0 100644
--- a/arch/um/drivers/xterm.c
+++ b/arch/um/drivers/xterm.c
@@ -151,6 +151,13 @@
goto out;
}
+ err = os_set_fd_block(new, 0);
+ if (err) {
+ printk("xterm_open : failed to set xterm descriptor "
+ "non-blocking, err = %d\n", -err);
+ goto out;
+ }
+
CATCH_EINTR(err = tcgetattr(new, &data->tt));
if(err){
new = err;