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uio: change to use the mutex lock instead of the spin lock

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We are hitting a regression with the following commit:

commit a93e7b3315
Author: Hamish Martin <hamish.martin@alliedtelesis.co.nz>
Date:   Mon May 14 13:32:23 2018 +1200

    uio: Prevent device destruction while fds are open

The problem is the addition of spin_lock_irqsave in uio_write. This
leads to hitting  uio_write -> copy_from_user -> _copy_from_user ->
might_fault and the logs filling up with sleeping warnings.

I also noticed some uio drivers allocate memory, sleep, grab mutexes
from callouts like open() and release and uio is now doing
spin_lock_irqsave while calling them.

Reported-by: Mike Christie <mchristi@redhat.com>
CC: Hamish Martin <hamish.martin@alliedtelesis.co.nz>
Reviewed-by: Hamish Martin <hamish.martin@alliedtelesis.co.nz>
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Xiubo Li
2018-07-06 22:05:38 -04:00
committed by Greg Kroah-Hartman
parent 9421e45f5f
commit 543af5861f
2 changed files with 14 additions and 20 deletions
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2
include/linux/uio_driver.h
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@@ -75,7 +75,7 @@ struct uio_device {
struct fasync_struct *async_queue;
wait_queue_head_t wait;
struct uio_info *info;
spinlock_t info_lock;
struct mutex info_lock;
struct kobject *map_dir;
struct kobject *portio_dir;
};