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Revision 35a9393c95b31870a74f51a3e7455f33f5657b6f authored by Peter Zijlstra on 26 February 2015, 15:23:11 UTC, committed by Ingo Molnar on 23 March 2015, 09:49:07 UTC 
lockdep: Fix the module unload key range freeing logic
 
Module unload calls lockdep_free_key_range(), which removes entries
from the data structures. Most of the lockdep code OTOH assumes the
data structures are append only; in specific see the comments in
add_lock_to_list() and look_up_lock_class().

Clearly this has only worked by accident; make it work proper. The
actual scenario to make it go boom would involve the memory freed by
the module unlock being re-allocated and re-used for a lock inside of
a rcu-sched grace period. This is a very unlikely scenario, still
better plug the hole.

Use RCU list iteration in all places and ammend the comments.

Change lockdep_free_key_range() to issue a sync_sched() between
removal from the lists and returning -- which results in the memory
being freed. Further ensure the callers are placed correctly and
comment the requirements.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrey Tsyvarev <tsyvarev@ispras.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
1 parent bc465aa
Raw File
hash_info.c 
/*
 * Hash Info: Hash algorithms information
 *
 * Copyright (c) 2013 Dmitry Kasatkin <d.kasatkin@samsung.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 <linux/export.h>
#include <crypto/hash_info.h>

const char *const hash_algo_name[HASH_ALGO__LAST] = {
	[HASH_ALGO_MD4]		= "md4",
	[HASH_ALGO_MD5]		= "md5",
	[HASH_ALGO_SHA1]	= "sha1",
	[HASH_ALGO_RIPE_MD_160]	= "rmd160",
	[HASH_ALGO_SHA256]	= "sha256",
	[HASH_ALGO_SHA384]	= "sha384",
	[HASH_ALGO_SHA512]	= "sha512",
	[HASH_ALGO_SHA224]	= "sha224",
	[HASH_ALGO_RIPE_MD_128]	= "rmd128",
	[HASH_ALGO_RIPE_MD_256]	= "rmd256",
	[HASH_ALGO_RIPE_MD_320]	= "rmd320",
	[HASH_ALGO_WP_256]	= "wp256",
	[HASH_ALGO_WP_384]	= "wp384",
	[HASH_ALGO_WP_512]	= "wp512",
	[HASH_ALGO_TGR_128]	= "tgr128",
	[HASH_ALGO_TGR_160]	= "tgr160",
	[HASH_ALGO_TGR_192]	= "tgr192",
};
EXPORT_SYMBOL_GPL(hash_algo_name);

const int hash_digest_size[HASH_ALGO__LAST] = {
	[HASH_ALGO_MD4]		= MD5_DIGEST_SIZE,
	[HASH_ALGO_MD5]		= MD5_DIGEST_SIZE,
	[HASH_ALGO_SHA1]	= SHA1_DIGEST_SIZE,
	[HASH_ALGO_RIPE_MD_160]	= RMD160_DIGEST_SIZE,
	[HASH_ALGO_SHA256]	= SHA256_DIGEST_SIZE,
	[HASH_ALGO_SHA384]	= SHA384_DIGEST_SIZE,
	[HASH_ALGO_SHA512]	= SHA512_DIGEST_SIZE,
	[HASH_ALGO_SHA224]	= SHA224_DIGEST_SIZE,
	[HASH_ALGO_RIPE_MD_128]	= RMD128_DIGEST_SIZE,
	[HASH_ALGO_RIPE_MD_256]	= RMD256_DIGEST_SIZE,
	[HASH_ALGO_RIPE_MD_320]	= RMD320_DIGEST_SIZE,
	[HASH_ALGO_WP_256]	= WP256_DIGEST_SIZE,
	[HASH_ALGO_WP_384]	= WP384_DIGEST_SIZE,
	[HASH_ALGO_WP_512]	= WP512_DIGEST_SIZE,
	[HASH_ALGO_TGR_128]	= TGR128_DIGEST_SIZE,
	[HASH_ALGO_TGR_160]	= TGR160_DIGEST_SIZE,
	[HASH_ALGO_TGR_192]	= TGR192_DIGEST_SIZE,
};
EXPORT_SYMBOL_GPL(hash_digest_size);
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