[PATCH] uml: use GFP_ATOMIC for allocations under spinlocks.

setup_initial_poll is only called with sigio_lock() held, so use appropriate
allocation.

Also, parse_chan() can also be called when holding a spinlock (see line_open()
 -> parse_chan_pair()).

I have sporadic problems (spinlock taken twice, with spinlock debugging on UP)
which could be caused by a sequence like "take spinlock, alloc and go to
sleep, take again the spinlock in the other thread".
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

arch/um/drivers/chan_kern.c

@@ -465,7 +465,7 @@ static struct chan *parse_chan(char *str, int pri, int device,
 	data = (*ops->init)(str, device, opts);
 	if(data == NULL) return(NULL);
 
-	chan = kmalloc(sizeof(*chan), GFP_KERNEL);
+	chan = kmalloc(sizeof(*chan), GFP_ATOMIC);
 	if(chan == NULL) return(NULL);
 	*chan = ((struct chan) { .list	 	= LIST_HEAD_INIT(chan->list),
 				 .primary	= 1,

arch/um/kernel/sigio_user.c

@@ -340,7 +340,7 @@ static int setup_initial_poll(int fd)
 {
 	struct pollfd *p;
 
-	p = um_kmalloc(sizeof(struct pollfd));
+	p = um_kmalloc_atomic(sizeof(struct pollfd));
 	if(p == NULL){
 		printk("setup_initial_poll : failed to allocate poll\n");
 		return(-1);