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Revision 871341023c771ad233620b7a1fb3d9c7031c4e5c authored by Johannes Weiner on 12 September 2013, 22:13:38 UTC, committed by Linus Torvalds on 12 September 2013, 22:38:01 UTC 
arch: mm: do not invoke OOM killer on kernel fault OOM
 
Kernel faults are expected to handle OOM conditions gracefully (gup,
uaccess etc.), so they should never invoke the OOM killer.  Reserve this
for faults triggered in user context when it is the only option.

Most architectures already do this, fix up the remaining few.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: azurIt <azurit@pobox.sk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 94bce45
Raw File
iodev.h 
/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#ifndef __KVM_IODEV_H__
#define __KVM_IODEV_H__

#include <linux/kvm_types.h>
#include <asm/errno.h>

struct kvm_io_device;

/**
 * kvm_io_device_ops are called under kvm slots_lock.
 * read and write handlers return 0 if the transaction has been handled,
 * or non-zero to have it passed to the next device.
 **/
struct kvm_io_device_ops {
	int (*read)(struct kvm_io_device *this,
		    gpa_t addr,
		    int len,
		    void *val);
	int (*write)(struct kvm_io_device *this,
		     gpa_t addr,
		     int len,
		     const void *val);
	void (*destructor)(struct kvm_io_device *this);
};


struct kvm_io_device {
	const struct kvm_io_device_ops *ops;
};

static inline void kvm_iodevice_init(struct kvm_io_device *dev,
				     const struct kvm_io_device_ops *ops)
{
	dev->ops = ops;
}

static inline int kvm_iodevice_read(struct kvm_io_device *dev,
				    gpa_t addr, int l, void *v)
{
	return dev->ops->read ? dev->ops->read(dev, addr, l, v) : -EOPNOTSUPP;
}

static inline int kvm_iodevice_write(struct kvm_io_device *dev,
				     gpa_t addr, int l, const void *v)
{
	return dev->ops->write ? dev->ops->write(dev, addr, l, v) : -EOPNOTSUPP;
}

static inline void kvm_iodevice_destructor(struct kvm_io_device *dev)
{
	if (dev->ops->destructor)
		dev->ops->destructor(dev);
}

#endif /* __KVM_IODEV_H__ */
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