Commit 61232f2f authored by Jeff Dike's avatar Jeff Dike Committed by Linus Torvalds

[PATCH] uml: fix exitcall ordering bug

This fixes an exitcall ordering bug - calls to ignore_sigio_fd can come from
exitcalls that come after the sigio thread has been killed.  This would cause
shutdown to hang or crash.

Fixed by having ignore_sigio_fd check that the thread is present before trying
to communicate with it.
Signed-off-by: default avatarJeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 8e64d96a
......@@ -191,6 +191,13 @@ int ignore_sigio_fd(int fd)
struct pollfd *p;
int err = 0, i, n = 0;
/* This is called from exitcalls elsewhere in UML - if
* sigio_cleanup has already run, then update_thread will hang
* or fail because the thread is no longer running.
*/
if(write_sigio_pid == -1)
return -EIO;
sigio_lock();
for(i = 0; i < current_poll.used; i++){
if(current_poll.poll[i].fd == fd) break;
......@@ -215,7 +222,7 @@ int ignore_sigio_fd(int fd)
update_thread();
out:
sigio_unlock();
return(err);
return err;
}
static struct pollfd *setup_initial_poll(int fd)
......
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