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Revision 0432a0a066b05361b6d4d26522233c3c76c9e5da authored by Linus Torvalds on 03 August 2019, 17:51:29 UTC, committed by Linus Torvalds on 03 August 2019, 17:51:29 UTC 
Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
 
Pull vdso timer fixes from Thomas Gleixner:
 "A series of commits to deal with the regression caused by the generic
  VDSO implementation.

  The usage of clock_gettime64() for 32bit compat fallback syscalls
  caused seccomp filters to kill innocent processes because they only
  allow clock_gettime().

  Handle the compat syscalls with clock_gettime() as before, which is
  not a functional problem for the VDSO as the legacy compat application
  interface is not y2038 safe anyway. It's just extra fallback code
  which needs to be implemented on every architecture.

  It's opt in for now so that it does not break the compile of already
  converted architectures in linux-next. Once these are fixed, the
  #ifdeffery goes away.

  So much for trying to be smart and reuse code..."

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  arm64: compat: vdso: Use legacy syscalls as fallback
  x86/vdso/32: Use 32bit syscall fallback
  lib/vdso/32: Provide legacy syscall fallbacks
  lib/vdso: Move fallback invocation to the callers
  lib/vdso/32: Remove inconsistent NULL pointer checks
2 parent s af42e74 + 33a5898
Raw File
libcrc32c.c 
// SPDX-License-Identifier: GPL-2.0-or-later
/* 
 * CRC32C
 *@Article{castagnoli-crc,
 * author =       { Guy Castagnoli and Stefan Braeuer and Martin Herrman},
 * title =        {{Optimization of Cyclic Redundancy-Check Codes with 24
 *                 and 32 Parity Bits}},
 * journal =      IEEE Transactions on Communication,
 * year =         {1993},
 * volume =       {41},
 * number =       {6},
 * pages =        {},
 * month =        {June},
 *}
 * Used by the iSCSI driver, possibly others, and derived from the
 * the iscsi-crc.c module of the linux-iscsi driver at
 * http://linux-iscsi.sourceforge.net.
 *
 * Following the example of lib/crc32, this function is intended to be
 * flexible and useful for all users.  Modules that currently have their
 * own crc32c, but hopefully may be able to use this one are:
 *  net/sctp (please add all your doco to here if you change to
 *            use this one!)
 *  <endoflist>
 *
 * Copyright (c) 2004 Cisco Systems, Inc.
 */

#include <crypto/hash.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/crc32c.h>

static struct crypto_shash *tfm;

u32 crc32c(u32 crc, const void *address, unsigned int length)
{
	SHASH_DESC_ON_STACK(shash, tfm);
	u32 ret, *ctx = (u32 *)shash_desc_ctx(shash);
	int err;

	shash->tfm = tfm;
	*ctx = crc;

	err = crypto_shash_update(shash, address, length);
	BUG_ON(err);

	ret = *ctx;
	barrier_data(ctx);
	return ret;
}

EXPORT_SYMBOL(crc32c);

static int __init libcrc32c_mod_init(void)
{
	tfm = crypto_alloc_shash("crc32c", 0, 0);
	return PTR_ERR_OR_ZERO(tfm);
}

static void __exit libcrc32c_mod_fini(void)
{
	crypto_free_shash(tfm);
}

const char *crc32c_impl(void)
{
	return crypto_shash_driver_name(tfm);
}
EXPORT_SYMBOL(crc32c_impl);

module_init(libcrc32c_mod_init);
module_exit(libcrc32c_mod_fini);

MODULE_AUTHOR("Clay Haapala <chaapala@cisco.com>");
MODULE_DESCRIPTION("CRC32c (Castagnoli) calculations");
MODULE_LICENSE("GPL");
MODULE_SOFTDEP("pre: crc32c");
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