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Revision be14eb619108fa8b7120eb2c42d66d5f623ae10e authored by Brian King on 10 September 2010, 07:03:21 UTC, committed by Jens Axboe on 10 September 2010, 07:03:21 UTC 
block: Range check cpu in blk_cpu_to_group
 
While testing CPU DLPAR, the following problem was discovered.
We were DLPAR removing the first CPU, which in this case was
logical CPUs 0-3. CPUs 0-2 were already marked offline and
we were in the process of offlining CPU 3. After marking
the CPU inactive and offline in cpu_disable, but before the
cpu was completely idle (cpu_die), we ended up in __make_request
on CPU 3. There we looked at the topology map to see which CPU
to complete the I/O on and found no CPUs in the cpu_sibling_map.
This resulted in the block layer setting the completion cpu
to be NR_CPUS, which then caused an oops when we tried to
complete the I/O.

Fix this by sanity checking the value we return from blk_cpu_to_group
to be a valid cpu value.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
1 parent edce682
Raw File
fips.c 
/*
 * FIPS 200 support.
 *
 * Copyright (c) 2008 Neil Horman <nhorman@tuxdriver.com>
 *
 * 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.
 *
 */

#include "internal.h"

int fips_enabled;
EXPORT_SYMBOL_GPL(fips_enabled);

/* Process kernel command-line parameter at boot time. fips=0 or fips=1 */
static int fips_enable(char *str)
{
	fips_enabled = !!simple_strtol(str, NULL, 0);
	printk(KERN_INFO "fips mode: %s\n",
		fips_enabled ? "enabled" : "disabled");
	return 1;
}

__setup("fips=", fips_enable);
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