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Revision e7b526bb852cdd67b24e174da6850222f8da41b1 authored by Chris Wilson on 02 June 2010, 07:30:48 UTC, committed by Linus Torvalds on 06 June 2010, 03:37:37 UTC 
drm/i915: Move non-phys cursors into the GTT
 
Cursors need to be in the GTT domain when being accessed by the GPU.
Previously this was a fortuitous byproduct of userspace using pwrite()
to upload the image data into the cursor. The redundant clflush was
removed in commit 9b8c4a and so the image was no longer being flushed
out of the caches into main memory. One could also devise a scenario
where the cursor was rendered by the GPU, prior to being attached as the
cursor, resulting in similar corruption due to the missing MI_FLUSH.

Fixes:

  Bug 28335 - Cursor corruption caused by commit 9b8c4a0b21
  https://bugs.freedesktop.org/show_bug.cgi?id=28335

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reported-and-tested-by: Jeff Chua <jeff.chua.linux@gmail.com>
Tested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: Andy Isaacson <adi@hexapodia.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 78b3655
Raw File
xt_u32.c 
/*
 *	xt_u32 - kernel module to match u32 packet content
 *
 *	Original author: Don Cohen <don@isis.cs3-inc.com>
 *	(C) CC Computer Consultants GmbH, 2007
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/spinlock.h>
#include <linux/skbuff.h>
#include <linux/types.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/xt_u32.h>

static bool u32_match_it(const struct xt_u32 *data,
			 const struct sk_buff *skb)
{
	const struct xt_u32_test *ct;
	unsigned int testind;
	unsigned int nnums;
	unsigned int nvals;
	unsigned int i;
	__be32 n;
	u_int32_t pos;
	u_int32_t val;
	u_int32_t at;

	/*
	 * Small example: "0 >> 28 == 4 && 8 & 0xFF0000 >> 16 = 6, 17"
	 * (=IPv4 and (TCP or UDP)). Outer loop runs over the "&&" operands.
	 */
	for (testind = 0; testind < data->ntests; ++testind) {
		ct  = &data->tests[testind];
		at  = 0;
		pos = ct->location[0].number;

		if (skb->len < 4 || pos > skb->len - 4)
			return false;

		if (skb_copy_bits(skb, pos, &n, sizeof(n)) < 0)
			BUG();
		val   = ntohl(n);
		nnums = ct->nnums;

		/* Inner loop runs over "&", "<<", ">>" and "@" operands */
		for (i = 1; i < nnums; ++i) {
			u_int32_t number = ct->location[i].number;
			switch (ct->location[i].nextop) {
			case XT_U32_AND:
				val &= number;
				break;
			case XT_U32_LEFTSH:
				val <<= number;
				break;
			case XT_U32_RIGHTSH:
				val >>= number;
				break;
			case XT_U32_AT:
				if (at + val < at)
					return false;
				at += val;
				pos = number;
				if (at + 4 < at || skb->len < at + 4 ||
				    pos > skb->len - at - 4)
					return false;

				if (skb_copy_bits(skb, at + pos, &n,
						    sizeof(n)) < 0)
					BUG();
				val = ntohl(n);
				break;
			}
		}

		/* Run over the "," and ":" operands */
		nvals = ct->nvalues;
		for (i = 0; i < nvals; ++i)
			if (ct->value[i].min <= val && val <= ct->value[i].max)
				break;

		if (i >= ct->nvalues)
			return false;
	}

	return true;
}

static bool u32_mt(const struct sk_buff *skb, struct xt_action_param *par)
{
	const struct xt_u32 *data = par->matchinfo;
	bool ret;

	ret = u32_match_it(data, skb);
	return ret ^ data->invert;
}

static struct xt_match xt_u32_mt_reg __read_mostly = {
	.name       = "u32",
	.revision   = 0,
	.family     = NFPROTO_UNSPEC,
	.match      = u32_mt,
	.matchsize  = sizeof(struct xt_u32),
	.me         = THIS_MODULE,
};

static int __init u32_mt_init(void)
{
	return xt_register_match(&xt_u32_mt_reg);
}

static void __exit u32_mt_exit(void)
{
	xt_unregister_match(&xt_u32_mt_reg);
}

module_init(u32_mt_init);
module_exit(u32_mt_exit);
MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
MODULE_DESCRIPTION("Xtables: arbitrary byte matching");
MODULE_LICENSE("GPL");
MODULE_ALIAS("ipt_u32");
MODULE_ALIAS("ip6t_u32");
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