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Revision 96044694b8511bc2b04df0776b4ba295cfe005c0 authored by Mathias Nyman on 11 September 2014, 10:55:50 UTC, committed by Greg Kroah-Hartman on 11 September 2014, 21:23:52 UTC 
xhci: fix oops when xhci resumes from hibernate with hw lpm capable devices
 
Resuming from hibernate (S4) will restart and re-initialize xHC.
The device contexts are freed and will be re-allocated later during device reset.

Usb core will disable link pm in device resume before device reset, which will
try to change the max exit latency, accessing the device contexts before they are re-allocated.

There is no need to zero (disable) the max exit latency when disabling hw lpm
for a freshly re-initialized xHC. So check that device context exists before
doing anything. The max exit latency will be set again after device reset when usb core
enables the link pm.

Reported-by: Imre Deak <imre.deak@intel.com>
Tested-by: Imre Deak <imre.deak@intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 parent 0eda06c
Raw File
dir.c 
/*
 * dir.c
 *
 * Copyright (c) 1999 Al Smith
 */

#include <linux/buffer_head.h>
#include "efs.h"

static int efs_readdir(struct file *, struct dir_context *);

const struct file_operations efs_dir_operations = {
	.llseek		= generic_file_llseek,
	.read		= generic_read_dir,
	.iterate	= efs_readdir,
};

const struct inode_operations efs_dir_inode_operations = {
	.lookup		= efs_lookup,
};

static int efs_readdir(struct file *file, struct dir_context *ctx)
{
	struct inode *inode = file_inode(file);
	efs_block_t		block;
	int			slot;

	if (inode->i_size & (EFS_DIRBSIZE-1))
		pr_warn("%s(): directory size not a multiple of EFS_DIRBSIZE\n",
			__func__);

	/* work out where this entry can be found */
	block = ctx->pos >> EFS_DIRBSIZE_BITS;

	/* each block contains at most 256 slots */
	slot  = ctx->pos & 0xff;

	/* look at all blocks */
	while (block < inode->i_blocks) {
		struct efs_dir		*dirblock;
		struct buffer_head *bh;

		/* read the dir block */
		bh = sb_bread(inode->i_sb, efs_bmap(inode, block));

		if (!bh) {
			pr_err("%s(): failed to read dir block %d\n",
			       __func__, block);
			break;
		}

		dirblock = (struct efs_dir *) bh->b_data; 

		if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) {
			pr_err("%s(): invalid directory block\n", __func__);
			brelse(bh);
			break;
		}

		for (; slot < dirblock->slots; slot++) {
			struct efs_dentry *dirslot;
			efs_ino_t inodenum;
			const char *nameptr;
			int namelen;

			if (dirblock->space[slot] == 0)
				continue;

			dirslot  = (struct efs_dentry *) (((char *) bh->b_data) + EFS_SLOTAT(dirblock, slot));

			inodenum = be32_to_cpu(dirslot->inode);
			namelen  = dirslot->namelen;
			nameptr  = dirslot->name;
			pr_debug("%s(): block %d slot %d/%d: inode %u, name \"%s\", namelen %u\n",
				 __func__, block, slot, dirblock->slots-1,
				 inodenum, nameptr, namelen);
			if (!namelen)
				continue;
			/* found the next entry */
			ctx->pos = (block << EFS_DIRBSIZE_BITS) | slot;

			/* sanity check */
			if (nameptr - (char *) dirblock + namelen > EFS_DIRBSIZE) {
				pr_warn("directory entry %d exceeds directory block\n",
					slot);
				continue;
			}

			/* copy filename and data in dirslot */
			if (!dir_emit(ctx, nameptr, namelen, inodenum, DT_UNKNOWN)) {
				brelse(bh);
				return 0;
			}
		}
		brelse(bh);

		slot = 0;
		block++;
	}
	ctx->pos = (block << EFS_DIRBSIZE_BITS) | slot;
	return 0;
}
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