mirror of
https://github.com/torvalds/linux
synced 2024-10-03 01:43:05 +00:00
9807e49b6a
Move all stat code specific to rng into the rng code. While we're at it, change the stats so that bytes and counts are always incremented even in case of error. This allows the reference counting to be removed as we can now increment the counters prior to the operation. After the operation we simply increase the error count if necessary. This is safe as errors can only occur synchronously (or rather, the existing code already ignored asynchronous errors which are only visible to the callback function). Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
260 lines
5.6 KiB
C
260 lines
5.6 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Cryptographic API.
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*
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* RNG operations.
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*
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* Copyright (c) 2008 Neil Horman <nhorman@tuxdriver.com>
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* Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au>
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*/
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#include <crypto/internal/rng.h>
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#include <linux/atomic.h>
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#include <linux/cryptouser.h>
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#include <linux/err.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/random.h>
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#include <linux/seq_file.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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#include <net/netlink.h>
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#include "internal.h"
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static DEFINE_MUTEX(crypto_default_rng_lock);
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struct crypto_rng *crypto_default_rng;
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EXPORT_SYMBOL_GPL(crypto_default_rng);
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static int crypto_default_rng_refcnt;
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int crypto_rng_reset(struct crypto_rng *tfm, const u8 *seed, unsigned int slen)
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{
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struct rng_alg *alg = crypto_rng_alg(tfm);
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u8 *buf = NULL;
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int err;
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if (IS_ENABLED(CONFIG_CRYPTO_STATS))
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atomic64_inc(&rng_get_stat(alg)->seed_cnt);
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if (!seed && slen) {
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buf = kmalloc(slen, GFP_KERNEL);
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err = -ENOMEM;
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if (!buf)
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goto out;
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err = get_random_bytes_wait(buf, slen);
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if (err)
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goto free_buf;
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seed = buf;
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}
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err = alg->seed(tfm, seed, slen);
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free_buf:
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kfree_sensitive(buf);
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out:
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return crypto_rng_errstat(alg, err);
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}
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EXPORT_SYMBOL_GPL(crypto_rng_reset);
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static int crypto_rng_init_tfm(struct crypto_tfm *tfm)
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{
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return 0;
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}
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static unsigned int seedsize(struct crypto_alg *alg)
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{
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struct rng_alg *ralg = container_of(alg, struct rng_alg, base);
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return ralg->seedsize;
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}
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#ifdef CONFIG_NET
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static int crypto_rng_report(struct sk_buff *skb, struct crypto_alg *alg)
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{
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struct crypto_report_rng rrng;
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memset(&rrng, 0, sizeof(rrng));
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strscpy(rrng.type, "rng", sizeof(rrng.type));
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rrng.seedsize = seedsize(alg);
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return nla_put(skb, CRYPTOCFGA_REPORT_RNG, sizeof(rrng), &rrng);
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}
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#else
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static int crypto_rng_report(struct sk_buff *skb, struct crypto_alg *alg)
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{
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return -ENOSYS;
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}
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#endif
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static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg)
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__maybe_unused;
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static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg)
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{
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seq_printf(m, "type : rng\n");
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seq_printf(m, "seedsize : %u\n", seedsize(alg));
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}
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static int __maybe_unused crypto_rng_report_stat(
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struct sk_buff *skb, struct crypto_alg *alg)
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{
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struct rng_alg *rng = __crypto_rng_alg(alg);
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struct crypto_istat_rng *istat;
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struct crypto_stat_rng rrng;
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istat = rng_get_stat(rng);
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memset(&rrng, 0, sizeof(rrng));
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strscpy(rrng.type, "rng", sizeof(rrng.type));
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rrng.stat_generate_cnt = atomic64_read(&istat->generate_cnt);
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rrng.stat_generate_tlen = atomic64_read(&istat->generate_tlen);
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rrng.stat_seed_cnt = atomic64_read(&istat->seed_cnt);
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rrng.stat_err_cnt = atomic64_read(&istat->err_cnt);
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return nla_put(skb, CRYPTOCFGA_STAT_RNG, sizeof(rrng), &rrng);
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}
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static const struct crypto_type crypto_rng_type = {
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.extsize = crypto_alg_extsize,
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.init_tfm = crypto_rng_init_tfm,
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#ifdef CONFIG_PROC_FS
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.show = crypto_rng_show,
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#endif
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.report = crypto_rng_report,
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#ifdef CONFIG_CRYPTO_STATS
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.report_stat = crypto_rng_report_stat,
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#endif
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.maskclear = ~CRYPTO_ALG_TYPE_MASK,
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.maskset = CRYPTO_ALG_TYPE_MASK,
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.type = CRYPTO_ALG_TYPE_RNG,
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.tfmsize = offsetof(struct crypto_rng, base),
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};
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struct crypto_rng *crypto_alloc_rng(const char *alg_name, u32 type, u32 mask)
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{
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return crypto_alloc_tfm(alg_name, &crypto_rng_type, type, mask);
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}
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EXPORT_SYMBOL_GPL(crypto_alloc_rng);
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int crypto_get_default_rng(void)
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{
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struct crypto_rng *rng;
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int err;
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mutex_lock(&crypto_default_rng_lock);
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if (!crypto_default_rng) {
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rng = crypto_alloc_rng("stdrng", 0, 0);
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err = PTR_ERR(rng);
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if (IS_ERR(rng))
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goto unlock;
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err = crypto_rng_reset(rng, NULL, crypto_rng_seedsize(rng));
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if (err) {
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crypto_free_rng(rng);
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goto unlock;
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}
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crypto_default_rng = rng;
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}
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crypto_default_rng_refcnt++;
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err = 0;
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unlock:
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mutex_unlock(&crypto_default_rng_lock);
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return err;
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}
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EXPORT_SYMBOL_GPL(crypto_get_default_rng);
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void crypto_put_default_rng(void)
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{
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mutex_lock(&crypto_default_rng_lock);
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crypto_default_rng_refcnt--;
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mutex_unlock(&crypto_default_rng_lock);
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}
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EXPORT_SYMBOL_GPL(crypto_put_default_rng);
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#if defined(CONFIG_CRYPTO_RNG) || defined(CONFIG_CRYPTO_RNG_MODULE)
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int crypto_del_default_rng(void)
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{
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int err = -EBUSY;
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mutex_lock(&crypto_default_rng_lock);
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if (crypto_default_rng_refcnt)
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goto out;
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crypto_free_rng(crypto_default_rng);
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crypto_default_rng = NULL;
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err = 0;
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out:
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mutex_unlock(&crypto_default_rng_lock);
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return err;
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}
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EXPORT_SYMBOL_GPL(crypto_del_default_rng);
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#endif
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int crypto_register_rng(struct rng_alg *alg)
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{
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struct crypto_istat_rng *istat = rng_get_stat(alg);
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struct crypto_alg *base = &alg->base;
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if (alg->seedsize > PAGE_SIZE / 8)
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return -EINVAL;
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base->cra_type = &crypto_rng_type;
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base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
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base->cra_flags |= CRYPTO_ALG_TYPE_RNG;
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if (IS_ENABLED(CONFIG_CRYPTO_STATS))
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memset(istat, 0, sizeof(*istat));
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return crypto_register_alg(base);
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}
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EXPORT_SYMBOL_GPL(crypto_register_rng);
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void crypto_unregister_rng(struct rng_alg *alg)
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{
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crypto_unregister_alg(&alg->base);
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}
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EXPORT_SYMBOL_GPL(crypto_unregister_rng);
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int crypto_register_rngs(struct rng_alg *algs, int count)
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{
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int i, ret;
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for (i = 0; i < count; i++) {
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ret = crypto_register_rng(algs + i);
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if (ret)
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goto err;
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}
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return 0;
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err:
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for (--i; i >= 0; --i)
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crypto_unregister_rng(algs + i);
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return ret;
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}
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EXPORT_SYMBOL_GPL(crypto_register_rngs);
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void crypto_unregister_rngs(struct rng_alg *algs, int count)
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{
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int i;
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for (i = count - 1; i >= 0; --i)
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crypto_unregister_rng(algs + i);
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}
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EXPORT_SYMBOL_GPL(crypto_unregister_rngs);
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("Random Number Generator");
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