/*
 * Copyright (c) 2008, Intel Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
 *
 * Author: Alexander Duyck <alexander.h.duyck@intel.com>
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>

#include <linux/tc_act/tc_skbedit.h>
#include <net/tc_act/tc_skbedit.h>

#define SKBEDIT_TAB_MASK     15

static unsigned int skbedit_net_id;
static struct tc_action_ops act_skbedit_ops;

static int tcf_skbedit(struct sk_buff *skb, const struct tc_action *a,
		       struct tcf_result *res)
{
	struct tcf_skbedit *d = to_skbedit(a);

	spin_lock(&d->tcf_lock);
	tcf_lastuse_update(&d->tcf_tm);
	bstats_update(&d->tcf_bstats, skb);

	if (d->flags & SKBEDIT_F_PRIORITY)
		skb->priority = d->priority;
	if (d->flags & SKBEDIT_F_QUEUE_MAPPING &&
	    skb->dev->real_num_tx_queues > d->queue_mapping)
		skb_set_queue_mapping(skb, d->queue_mapping);
	if (d->flags & SKBEDIT_F_MARK) {
		skb->mark &= ~d->mask;
		skb->mark |= d->mark & d->mask;
	}
	if (d->flags & SKBEDIT_F_PTYPE)
		skb->pkt_type = d->ptype;

	spin_unlock(&d->tcf_lock);
	return d->tcf_action;
}

static const struct nla_policy skbedit_policy[TCA_SKBEDIT_MAX + 1] = {
	[TCA_SKBEDIT_PARMS]		= { .len = sizeof(struct tc_skbedit) },
	[TCA_SKBEDIT_PRIORITY]		= { .len = sizeof(u32) },
	[TCA_SKBEDIT_QUEUE_MAPPING]	= { .len = sizeof(u16) },
	[TCA_SKBEDIT_MARK]		= { .len = sizeof(u32) },
	[TCA_SKBEDIT_PTYPE]		= { .len = sizeof(u16) },
	[TCA_SKBEDIT_MASK]		= { .len = sizeof(u32) },
};

static int tcf_skbedit_init(struct net *net, struct nlattr *nla,
			    struct nlattr *est, struct tc_action **a,
			    int ovr, int bind)
{
	struct tc_action_net *tn = net_generic(net, skbedit_net_id);
	struct nlattr *tb[TCA_SKBEDIT_MAX + 1];
	struct tc_skbedit *parm;
	struct tcf_skbedit *d;
	u32 flags = 0, *priority = NULL, *mark = NULL, *mask = NULL;
	u16 *queue_mapping = NULL, *ptype = NULL;
	bool exists = false;
	int ret = 0, err;

	if (nla == NULL)
		return -EINVAL;

	err = nla_parse_nested(tb, TCA_SKBEDIT_MAX, nla, skbedit_policy);
	if (err < 0)
		return err;

	if (tb[TCA_SKBEDIT_PARMS] == NULL)
		return -EINVAL;

	if (tb[TCA_SKBEDIT_PRIORITY] != NULL) {
		flags |= SKBEDIT_F_PRIORITY;
		priority = nla_data(tb[TCA_SKBEDIT_PRIORITY]);
	}

	if (tb[TCA_SKBEDIT_QUEUE_MAPPING] != NULL) {
		flags |= SKBEDIT_F_QUEUE_MAPPING;
		queue_mapping = nla_data(tb[TCA_SKBEDIT_QUEUE_MAPPING]);
	}

	if (tb[TCA_SKBEDIT_PTYPE] != NULL) {
		ptype = nla_data(tb[TCA_SKBEDIT_PTYPE]);
		if (!skb_pkt_type_ok(*ptype))
			return -EINVAL;
		flags |= SKBEDIT_F_PTYPE;
	}

	if (tb[TCA_SKBEDIT_MARK] != NULL) {
		flags |= SKBEDIT_F_MARK;
		mark = nla_data(tb[TCA_SKBEDIT_MARK]);
	}

	if (tb[TCA_SKBEDIT_MASK] != NULL) {
		flags |= SKBEDIT_F_MASK;
		mask = nla_data(tb[TCA_SKBEDIT_MASK]);
	}

	parm = nla_data(tb[TCA_SKBEDIT_PARMS]);

	exists = tcf_hash_check(tn, parm->index, a, bind);
	if (exists && bind)
		return 0;

	if (!flags) {
		tcf_hash_release(*a, bind);
		return -EINVAL;
	}

	if (!exists) {
		ret = tcf_hash_create(tn, parm->index, est, a,
				      &act_skbedit_ops, bind, false);
		if (ret)
			return ret;

		d = to_skbedit(*a);
		ret = ACT_P_CREATED;
	} else {
		d = to_skbedit(*a);
		tcf_hash_release(*a, bind);
		if (!ovr)
			return -EEXIST;
	}

	spin_lock_bh(&d->tcf_lock);

	d->flags = flags;
	if (flags & SKBEDIT_F_PRIORITY)
		d->priority = *priority;
	if (flags & SKBEDIT_F_QUEUE_MAPPING)
		d->queue_mapping = *queue_mapping;
	if (flags & SKBEDIT_F_MARK)
		d->mark = *mark;
	if (flags & SKBEDIT_F_PTYPE)
		d->ptype = *ptype;
	/* default behaviour is to use all the bits */
	d->mask = 0xffffffff;
	if (flags & SKBEDIT_F_MASK)
		d->mask = *mask;

	d->tcf_action = parm->action;

	spin_unlock_bh(&d->tcf_lock);

	if (ret == ACT_P_CREATED)
		tcf_hash_insert(tn, *a);
	return ret;
}

static int tcf_skbedit_dump(struct sk_buff *skb, struct tc_action *a,
			    int bind, int ref)
{
	unsigned char *b = skb_tail_pointer(skb);
	struct tcf_skbedit *d = to_skbedit(a);
	struct tc_skbedit opt = {
		.index   = d->tcf_index,
		.refcnt  = d->tcf_refcnt - ref,
		.bindcnt = d->tcf_bindcnt - bind,
		.action  = d->tcf_action,
	};
	struct tcf_t t;

	if (nla_put(skb, TCA_SKBEDIT_PARMS, sizeof(opt), &opt))
		goto nla_put_failure;
	if ((d->flags & SKBEDIT_F_PRIORITY) &&
	    nla_put_u32(skb, TCA_SKBEDIT_PRIORITY, d->priority))
		goto nla_put_failure;
	if ((d->flags & SKBEDIT_F_QUEUE_MAPPING) &&
	    nla_put_u16(skb, TCA_SKBEDIT_QUEUE_MAPPING, d->queue_mapping))
		goto nla_put_failure;
	if ((d->flags & SKBEDIT_F_MARK) &&
	    nla_put_u32(skb, TCA_SKBEDIT_MARK, d->mark))
		goto nla_put_failure;
	if ((d->flags & SKBEDIT_F_PTYPE) &&
	    nla_put_u16(skb, TCA_SKBEDIT_PTYPE, d->ptype))
		goto nla_put_failure;
	if ((d->flags & SKBEDIT_F_MASK) &&
	    nla_put_u32(skb, TCA_SKBEDIT_MASK, d->mask))
		goto nla_put_failure;

	tcf_tm_dump(&t, &d->tcf_tm);
	if (nla_put_64bit(skb, TCA_SKBEDIT_TM, sizeof(t), &t, TCA_SKBEDIT_PAD))
		goto nla_put_failure;
	return skb->len;

nla_put_failure:
	nlmsg_trim(skb, b);
	return -1;
}

static int tcf_skbedit_walker(struct net *net, struct sk_buff *skb,
			      struct netlink_callback *cb, int type,
			      const struct tc_action_ops *ops)
{
	struct tc_action_net *tn = net_generic(net, skbedit_net_id);

	return tcf_generic_walker(tn, skb, cb, type, ops);
}

static int tcf_skbedit_search(struct net *net, struct tc_action **a, u32 index)
{
	struct tc_action_net *tn = net_generic(net, skbedit_net_id);

	return tcf_hash_search(tn, a, index);
}

static struct tc_action_ops act_skbedit_ops = {
	.kind		=	"skbedit",
	.type		=	TCA_ACT_SKBEDIT,
	.owner		=	THIS_MODULE,
	.act		=	tcf_skbedit,
	.dump		=	tcf_skbedit_dump,
	.init		=	tcf_skbedit_init,
	.walk		=	tcf_skbedit_walker,
	.lookup		=	tcf_skbedit_search,
	.size		=	sizeof(struct tcf_skbedit),
};

static __net_init int skbedit_init_net(struct net *net)
{
	struct tc_action_net *tn = net_generic(net, skbedit_net_id);

	return tc_action_net_init(tn, &act_skbedit_ops, SKBEDIT_TAB_MASK);
}

static void __net_exit skbedit_exit_net(struct net *net)
{
	struct tc_action_net *tn = net_generic(net, skbedit_net_id);

	tc_action_net_exit(tn);
}

static struct pernet_operations skbedit_net_ops = {
	.init = skbedit_init_net,
	.exit = skbedit_exit_net,
	.id   = &skbedit_net_id,
	.size = sizeof(struct tc_action_net),
};

MODULE_AUTHOR("Alexander Duyck, <alexander.h.duyck@intel.com>");
MODULE_DESCRIPTION("SKB Editing");
MODULE_LICENSE("GPL");

static int __init skbedit_init_module(void)
{
	return tcf_register_action(&act_skbedit_ops, &skbedit_net_ops);
}

static void __exit skbedit_cleanup_module(void)
{
	tcf_unregister_action(&act_skbedit_ops, &skbedit_net_ops);
}

module_init(skbedit_init_module);
module_exit(skbedit_cleanup_module);
_kms_helper]
    drm_fb_helper_restore_fbdev_mode_unlocked+0x34/0x80 [drm_kms_helper]
    drm_fb_helper_set_par+0x2d/0x60 [drm_kms_helper]
    intel_fbdev_set_par+0x18/0x70 [i915]
    fb_set_var+0x236/0x460
    fbcon_blank+0x30f/0x350
    do_unblank_screen+0xd2/0x1a0
    vt_ioctl+0x507/0x12a0
    tty_ioctl+0x355/0xc30
    do_vfs_ioctl+0xa3/0x5e0
    SyS_ioctl+0x79/0x90
    entry_SYSCALL_64_fastpath+0x13/0x94

 - i915 unpin_work workqueue:

    intel_unpin_work_fn+0x58/0x140 [i915]
    process_one_work+0x1f1/0x480
    worker_thread+0x48/0x4d0
    kthread+0x101/0x140

and this patch purely papers over the issue by adding a NULL pointer
check and a WARN_ON_ONCE() to avoid the oops that would then generally
make the machine unresponsive.

Other callers of i915_gem_object_to_ggtt() seem to also check for the
returned pointer being NULL and warn about it, so this clearly has
happened before in other places.

[ Reported it originally to the i915 developers on Jan 8, applying the
  ugly workaround on my own now after triggering the problem for the
  second time with no feedback.

  This is likely to be the same bug reported as

     https://bugs.freedesktop.org/show_bug.cgi?id=98829
     https://bugs.freedesktop.org/show_bug.cgi?id=99134

  which has a patch for the underlying problem, but it hasn't gotten to
  me, so I'm applying the workaround. ]

Cc: Daniel Vetter &lt;daniel.vetter@intel.com&gt;
Cc: Jani Nikula &lt;jani.nikula@linux.intel.com&gt;
Cc: Ville Syrjälä &lt;ville.syrjala@linux.intel.com&gt;
Cc: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Cc: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;
Cc: Tvrtko Ursulin &lt;tvrtko.ursulin@intel.com&gt;
Cc: Imre Deak &lt;imre.deak@intel.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>Diffstat</a> (limited to 'net/batman-adv/gateway_client.h')</div><table summary='diffstat' class='diffstat'>