Revision 80ef4464d5e27408685e609d389663aad46644b9 authored by Robert Richter on 20 March 2019, 18:57:23 UTC, committed by Joerg Roedel on 22 March 2019, 11:01:58 UTC
If a 32 bit allocation request is too big to possibly succeed, it
early exits with a failure and then should never update max32_alloc_
size. This patch fixes current code, now the size is only updated if
the slow path failed while walking the tree. Without the fix the
allocation may enter the slow path again even if there was a failure
before of a request with the same or a smaller size.

Cc: <stable@vger.kernel.org> # 4.20+
Fixes: bee60e94a1e2 ("iommu/iova: Optimise attempts to allocate iova from 32bit address range")
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Robert Richter <rrichter@marvell.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
1 parent 4e50ce0
Raw File
eisa_eeprom.c
/* 
 *    EISA "eeprom" support routines
 *
 *    Copyright (C) 2001 Thomas Bogendoerfer <tsbogend at parisc-linux.org>
 *
 *
 *    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, or
 *    (at your option) any later version.
 *
 *    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, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/miscdevice.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <asm/io.h>
#include <linux/uaccess.h>
#include <asm/eisa_eeprom.h>

#define 	EISA_EEPROM_MINOR 241

static loff_t eisa_eeprom_llseek(struct file *file, loff_t offset, int origin)
{
	return fixed_size_llseek(file, offset, origin, HPEE_MAX_LENGTH);
}

static ssize_t eisa_eeprom_read(struct file * file,
			      char __user *buf, size_t count, loff_t *ppos )
{
	unsigned char *tmp;
	ssize_t ret;
	int i;
	
	if (*ppos < 0 || *ppos >= HPEE_MAX_LENGTH)
		return 0;
	
	count = *ppos + count < HPEE_MAX_LENGTH ? count : HPEE_MAX_LENGTH - *ppos;
	tmp = kmalloc(count, GFP_KERNEL);
	if (tmp) {
		for (i = 0; i < count; i++)
			tmp[i] = readb(eisa_eeprom_addr+(*ppos)++);

		if (copy_to_user (buf, tmp, count))
			ret = -EFAULT;
		else
			ret = count;
		kfree (tmp);
	} else
		ret = -ENOMEM;
	
	return ret;
}

static int eisa_eeprom_open(struct inode *inode, struct file *file)
{
	if (file->f_mode & FMODE_WRITE)
		return -EINVAL;
   
	return 0;
}

static int eisa_eeprom_release(struct inode *inode, struct file *file)
{
	return 0;
}

/*
 *	The various file operations we support.
 */
static const struct file_operations eisa_eeprom_fops = {
	.owner =	THIS_MODULE,
	.llseek =	eisa_eeprom_llseek,
	.read =		eisa_eeprom_read,
	.open =		eisa_eeprom_open,
	.release =	eisa_eeprom_release,
};

static struct miscdevice eisa_eeprom_dev = {
	EISA_EEPROM_MINOR,
	"eisa_eeprom",
	&eisa_eeprom_fops
};

static int __init eisa_eeprom_init(void)
{
	int retval;

	if (!eisa_eeprom_addr)
		return -ENODEV;

	retval = misc_register(&eisa_eeprom_dev);
	if (retval < 0) {
		printk(KERN_ERR "EISA EEPROM: cannot register misc device.\n");
		return retval;
	}

	printk(KERN_INFO "EISA EEPROM at 0x%px\n", eisa_eeprom_addr);
	return 0;
}

MODULE_LICENSE("GPL");

module_init(eisa_eeprom_init);
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