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Commit 6dc659d8 authored by Ingo Molnar's avatar Ingo Molnar Committed by Linus Torvalds
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[PATCH] drivers/block/floppy.c: dont free_irq() from irq context 



free_irq() should not be executed from softirq context.

Found by the lock validator.  The fix is to push fd_free_irq() into
keventd.  The code validates fine with this patch applied.

(akpm: this is revolting, but so is floppy.c)

[akpm@osdl.org: added flush_scheduled_work()]
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 36ddf5bb

drivers/block/floppy.c

+22 −1
Original line number Diff line number Diff line
@@ -250,6 +250,18 @@ static int irqdma_allocated; 
#include <linux/cdrom.h>	/* for the compatibility eject ioctl */

#include <linux/completion.h>



/*

 * Interrupt freeing also means /proc VFS work - dont do it

 * from interrupt context. We push this work into keventd:

 */

static void fd_free_irq_fn(void *data)

{

	fd_free_irq();

}



static DECLARE_WORK(fd_free_irq_work, fd_free_irq_fn, NULL);





static struct request *current_req;

static struct request_queue *floppy_queue;

static void do_fd_request(request_queue_t * q);
@@ -4433,6 +4445,13 @@ static int floppy_grab_irq_and_dma(void) 
		return 0;

	}

	spin_unlock_irqrestore(&floppy_usage_lock, flags);



	/*

	 * We might have scheduled a free_irq(), wait it to

	 * drain first:

	 */

	flush_scheduled_work();



	if (fd_request_irq()) {

		DPRINT("Unable to grab IRQ%d for the floppy driver\n",

		       FLOPPY_IRQ);
@@ -4522,7 +4541,7 @@ static void floppy_release_irq_and_dma(void) 
	if (irqdma_allocated) {

		fd_disable_dma();

		fd_free_dma();

		fd_free_irq();

		schedule_work(&fd_free_irq_work);

		irqdma_allocated = 0;

	}

	set_dor(0, ~0, 8);
@@ -4633,6 +4652,8 @@ void cleanup_module(void) 
	/* eject disk, if any */

	fd_eject(0);



	flush_scheduled_work();		/* fd_free_irq() might be pending */



	wait_for_completion(&device_release);

}