Commit 79ae2cb8 authored Sep 22, 2005 by Paolo 'Blaisorblade' Giarrusso Committed by Linus Torvalds Sep 22, 2005

[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: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

parent 46db4a42

arch/um/drivers/chan_kern.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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

+1 −1

Original line number	Diff line number	Diff line
		@@ -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);