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/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){