crypto: rng - Count error stats differently

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>

1 files changed, 42 insertions, 11 deletions

diff --git a/crypto/rng.c b/crypto/rng.c
index fea082b25fe4..ef56c71bda50 100644
--- a/crypto/rng.c
+++ b/crypto/rng.c
@@ -8,17 +8,17 @@
  * Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au>
  */
 
-#include <linux/atomic.h>
 #include <crypto/internal/rng.h>
+#include <linux/atomic.h>
+#include <linux/cryptouser.h>
 #include <linux/err.h>
+#include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/random.h>
 #include <linux/seq_file.h>
 #include <linux/slab.h>
 #include <linux/string.h>
-#include <linux/cryptouser.h>
-#include <linux/compiler.h>
 #include <net/netlink.h>
 
 #include "internal.h"
@@ -30,27 +30,30 @@ static int crypto_default_rng_refcnt;
 
 int crypto_rng_reset(struct crypto_rng *tfm, const u8 *seed, unsigned int slen)
 {
-	struct crypto_alg *alg = tfm->base.__crt_alg;
+	struct rng_alg *alg = crypto_rng_alg(tfm);
 	u8 *buf = NULL;
 	int err;
 
+	if (IS_ENABLED(CONFIG_CRYPTO_STATS))
+		atomic64_inc(&rng_get_stat(alg)->seed_cnt);
+
 	if (!seed && slen) {
 		buf = kmalloc(slen, GFP_KERNEL);
+		err = -ENOMEM;
 		if (!buf)
-			return -ENOMEM;
+			goto out;
 
 		err = get_random_bytes_wait(buf, slen);
 		if (err)
-			goto out;
+			goto free_buf;
 		seed = buf;
 	}
 
-	crypto_stats_get(alg);
-	err = crypto_rng_alg(tfm)->seed(tfm, seed, slen);
-	crypto_stats_rng_seed(alg, err);
-out:
+	err = alg->seed(tfm, seed, slen);
+free_buf:
 	kfree_sensitive(buf);
-	return err;
+out:
+	return crypto_rng_errstat(alg, err);
 }
 EXPORT_SYMBOL_GPL(crypto_rng_reset);
 
@@ -94,6 +97,27 @@ static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg)
 	seq_printf(m, "seedsize     : %u\n", seedsize(alg));
 }
 
+static int __maybe_unused crypto_rng_report_stat(
+	struct sk_buff *skb, struct crypto_alg *alg)
+{
+	struct rng_alg *rng = __crypto_rng_alg(alg);
+	struct crypto_istat_rng *istat;
+	struct crypto_stat_rng rrng;
+
+	istat = rng_get_stat(rng);
+
+	memset(&rrng, 0, sizeof(rrng));
+
+	strscpy(rrng.type, "rng", sizeof(rrng.type));
+
+	rrng.stat_generate_cnt = atomic64_read(&istat->generate_cnt);
+	rrng.stat_generate_tlen = atomic64_read(&istat->generate_tlen);
+	rrng.stat_seed_cnt = atomic64_read(&istat->seed_cnt);
+	rrng.stat_err_cnt = atomic64_read(&istat->err_cnt);
+
+	return nla_put(skb, CRYPTOCFGA_STAT_RNG, sizeof(rrng), &rrng);
+}
+
 static const struct crypto_type crypto_rng_type = {
 	.extsize = crypto_alg_extsize,
 	.init_tfm = crypto_rng_init_tfm,
@@ -101,6 +125,9 @@ static const struct crypto_type crypto_rng_type = {
 	.show = crypto_rng_show,
 #endif
 	.report = crypto_rng_report,
+#ifdef CONFIG_CRYPTO_STATS
+	.report_stat = crypto_rng_report_stat,
+#endif
 	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
 	.maskset = CRYPTO_ALG_TYPE_MASK,
 	.type = CRYPTO_ALG_TYPE_RNG,
@@ -176,6 +203,7 @@ EXPORT_SYMBOL_GPL(crypto_del_default_rng);
 
 int crypto_register_rng(struct rng_alg *alg)
 {
+	struct crypto_istat_rng *istat = rng_get_stat(alg);
 	struct crypto_alg *base = &alg->base;
 
 	if (alg->seedsize > PAGE_SIZE / 8)
@@ -185,6 +213,9 @@ int crypto_register_rng(struct rng_alg *alg)
 	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 	base->cra_flags |= CRYPTO_ALG_TYPE_RNG;
 
+	if (IS_ENABLED(CONFIG_CRYPTO_STATS))
+		memset(istat, 0, sizeof(*istat));
+
 	return crypto_register_alg(base);
 }
 EXPORT_SYMBOL_GPL(crypto_register_rng);