From: Eric Biggers <[email protected]>
The performance of the crypto fuzz tests has greatly regressed since
v5.18. When booting a kernel on an arm64 dev board with all software
crypto algorithms and CONFIG_CRYPTO_MANAGER_EXTRA_TESTS enabled, the
fuzz tests now take about 200 seconds to run, or about 325 seconds with
lockdep enabled, compared to about 5 seconds before.
The root cause is that the random number generation has become much
slower due to commit d4150779e60f ("random32: use real rng for
non-deterministic randomness"). On my same arm64 dev board, at the time
the fuzz tests are run, get_random_u8() is about 345x slower than
prandom_u32_state(), or about 469x if lockdep is enabled.
Lockdep makes a big difference, but much of the rest comes from the
get_random_*() functions taking a *very* slow path when the CRNG is not
yet initialized. Since the crypto self-tests run early during boot,
even having a hardware RNG driver enabled (CONFIG_CRYPTO_DEV_QCOM_RNG in
my case) doesn't prevent this. x86 systems don't have this issue, but
they still see a significant regression if lockdep is enabled.
Converting the "Fully random bytes" case in generate_random_bytes() to
use get_random_bytes() helps significantly, improving the test time to
about 27 seconds. But that's still over 5x slower than before.
This is all a bit silly, though, since the fuzz tests don't actually
need cryptographically secure random numbers. So let's just make them
use a non-cryptographically-secure RNG as they did before. The original
prandom_u32() is gone now, so let's use prandom_u32_state() instead,
with an explicitly managed state, like various other self-tests in the
kernel source tree (rbtree_test.c, test_scanf.c, etc.) already do. This
also has the benefit that no locking is required anymore, so performance
should be even better than the original version that used prandom_u32().
Fixes: d4150779e60f ("random32: use real rng for non-deterministic randomness")
Cc: [email protected]
Signed-off-by: Eric Biggers <[email protected]>
---
v2: made init_rnd_state() use get_random_u64()
crypto/testmgr.c | 266 ++++++++++++++++++++++++++++++-----------------
1 file changed, 169 insertions(+), 97 deletions(-)
diff --git a/crypto/testmgr.c b/crypto/testmgr.c
index c91e93ece20b..b160eeb12c8e 100644
--- a/crypto/testmgr.c
+++ b/crypto/testmgr.c
@@ -860,12 +860,50 @@ static int prepare_keybuf(const u8 *key, unsigned int ksize,
#ifdef CONFIG_CRYPTO_MANAGER_EXTRA_TESTS
+/*
+ * The fuzz tests use prandom instead of the normal Linux RNG since they don't
+ * need cryptographically secure random numbers. This greatly improves the
+ * performance of these tests, especially if they are run before the Linux RNG
+ * has been initialized or if they are run on a lockdep-enabled kernel.
+ */
+
+static inline void init_rnd_state(struct rnd_state *rng)
+{
+ prandom_seed_state(rng, get_random_u64());
+}
+
+static inline u8 prandom_u8(struct rnd_state *rng)
+{
+ return prandom_u32_state(rng);
+}
+
+static inline u32 prandom_u32_below(struct rnd_state *rng, u32 ceil)
+{
+ /*
+ * This is slightly biased for non-power-of-2 values of 'ceil', but this
+ * isn't important here.
+ */
+ return prandom_u32_state(rng) % ceil;
+}
+
+static inline bool prandom_bool(struct rnd_state *rng)
+{
+ return prandom_u32_below(rng, 2);
+}
+
+static inline u32 prandom_u32_inclusive(struct rnd_state *rng,
+ u32 floor, u32 ceil)
+{
+ return floor + prandom_u32_below(rng, ceil - floor + 1);
+}
+
/* Generate a random length in range [0, max_len], but prefer smaller values */
-static unsigned int generate_random_length(unsigned int max_len)
+static unsigned int generate_random_length(struct rnd_state *rng,
+ unsigned int max_len)
{
- unsigned int len = get_random_u32_below(max_len + 1);
+ unsigned int len = prandom_u32_below(rng, max_len + 1);
- switch (get_random_u32_below(4)) {
+ switch (prandom_u32_below(rng, 4)) {
case 0:
return len % 64;
case 1:
@@ -878,43 +916,44 @@ static unsigned int generate_random_length(unsigned int max_len)
}
/* Flip a random bit in the given nonempty data buffer */
-static void flip_random_bit(u8 *buf, size_t size)
+static void flip_random_bit(struct rnd_state *rng, u8 *buf, size_t size)
{
size_t bitpos;
- bitpos = get_random_u32_below(size * 8);
+ bitpos = prandom_u32_below(rng, size * 8);
buf[bitpos / 8] ^= 1 << (bitpos % 8);
}
/* Flip a random byte in the given nonempty data buffer */
-static void flip_random_byte(u8 *buf, size_t size)
+static void flip_random_byte(struct rnd_state *rng, u8 *buf, size_t size)
{
- buf[get_random_u32_below(size)] ^= 0xff;
+ buf[prandom_u32_below(rng, size)] ^= 0xff;
}
/* Sometimes make some random changes to the given nonempty data buffer */
-static void mutate_buffer(u8 *buf, size_t size)
+static void mutate_buffer(struct rnd_state *rng, u8 *buf, size_t size)
{
size_t num_flips;
size_t i;
/* Sometimes flip some bits */
- if (get_random_u32_below(4) == 0) {
- num_flips = min_t(size_t, 1 << get_random_u32_below(8), size * 8);
+ if (prandom_u32_below(rng, 4) == 0) {
+ num_flips = min_t(size_t, 1 << prandom_u32_below(rng, 8),
+ size * 8);
for (i = 0; i < num_flips; i++)
- flip_random_bit(buf, size);
+ flip_random_bit(rng, buf, size);
}
/* Sometimes flip some bytes */
- if (get_random_u32_below(4) == 0) {
- num_flips = min_t(size_t, 1 << get_random_u32_below(8), size);
+ if (prandom_u32_below(rng, 4) == 0) {
+ num_flips = min_t(size_t, 1 << prandom_u32_below(rng, 8), size);
for (i = 0; i < num_flips; i++)
- flip_random_byte(buf, size);
+ flip_random_byte(rng, buf, size);
}
}
/* Randomly generate 'count' bytes, but sometimes make them "interesting" */
-static void generate_random_bytes(u8 *buf, size_t count)
+static void generate_random_bytes(struct rnd_state *rng, u8 *buf, size_t count)
{
u8 b;
u8 increment;
@@ -923,11 +962,11 @@ static void generate_random_bytes(u8 *buf, size_t count)
if (count == 0)
return;
- switch (get_random_u32_below(8)) { /* Choose a generation strategy */
+ switch (prandom_u32_below(rng, 8)) { /* Choose a generation strategy */
case 0:
case 1:
/* All the same byte, plus optional mutations */
- switch (get_random_u32_below(4)) {
+ switch (prandom_u32_below(rng, 4)) {
case 0:
b = 0x00;
break;
@@ -935,28 +974,28 @@ static void generate_random_bytes(u8 *buf, size_t count)
b = 0xff;
break;
default:
- b = get_random_u8();
+ b = prandom_u8(rng);
break;
}
memset(buf, b, count);
- mutate_buffer(buf, count);
+ mutate_buffer(rng, buf, count);
break;
case 2:
/* Ascending or descending bytes, plus optional mutations */
- increment = get_random_u8();
- b = get_random_u8();
+ increment = prandom_u8(rng);
+ b = prandom_u8(rng);
for (i = 0; i < count; i++, b += increment)
buf[i] = b;
- mutate_buffer(buf, count);
+ mutate_buffer(rng, buf, count);
break;
default:
/* Fully random bytes */
- for (i = 0; i < count; i++)
- buf[i] = get_random_u8();
+ prandom_bytes_state(rng, buf, count);
}
}
-static char *generate_random_sgl_divisions(struct test_sg_division *divs,
+static char *generate_random_sgl_divisions(struct rnd_state *rng,
+ struct test_sg_division *divs,
size_t max_divs, char *p, char *end,
bool gen_flushes, u32 req_flags)
{
@@ -967,24 +1006,26 @@ static char *generate_random_sgl_divisions(struct test_sg_division *divs,
unsigned int this_len;
const char *flushtype_str;
- if (div == &divs[max_divs - 1] || get_random_u32_below(2) == 0)
+ if (div == &divs[max_divs - 1] || prandom_bool(rng))
this_len = remaining;
else
- this_len = get_random_u32_inclusive(1, remaining);
+ this_len = prandom_u32_inclusive(rng, 1, remaining);
div->proportion_of_total = this_len;
- if (get_random_u32_below(4) == 0)
- div->offset = get_random_u32_inclusive(PAGE_SIZE - 128, PAGE_SIZE - 1);
- else if (get_random_u32_below(2) == 0)
- div->offset = get_random_u32_below(32);
+ if (prandom_u32_below(rng, 4) == 0)
+ div->offset = prandom_u32_inclusive(rng,
+ PAGE_SIZE - 128,
+ PAGE_SIZE - 1);
+ else if (prandom_bool(rng))
+ div->offset = prandom_u32_below(rng, 32);
else
- div->offset = get_random_u32_below(PAGE_SIZE);
- if (get_random_u32_below(8) == 0)
+ div->offset = prandom_u32_below(rng, PAGE_SIZE);
+ if (prandom_u32_below(rng, 8) == 0)
div->offset_relative_to_alignmask = true;
div->flush_type = FLUSH_TYPE_NONE;
if (gen_flushes) {
- switch (get_random_u32_below(4)) {
+ switch (prandom_u32_below(rng, 4)) {
case 0:
div->flush_type = FLUSH_TYPE_REIMPORT;
break;
@@ -996,7 +1037,7 @@ static char *generate_random_sgl_divisions(struct test_sg_division *divs,
if (div->flush_type != FLUSH_TYPE_NONE &&
!(req_flags & CRYPTO_TFM_REQ_MAY_SLEEP) &&
- get_random_u32_below(2) == 0)
+ prandom_bool(rng))
div->nosimd = true;
switch (div->flush_type) {
@@ -1031,7 +1072,8 @@ static char *generate_random_sgl_divisions(struct test_sg_division *divs,
}
/* Generate a random testvec_config for fuzz testing */
-static void generate_random_testvec_config(struct testvec_config *cfg,
+static void generate_random_testvec_config(struct rnd_state *rng,
+ struct testvec_config *cfg,
char *name, size_t max_namelen)
{
char *p = name;
@@ -1043,7 +1085,7 @@ static void generate_random_testvec_config(struct testvec_config *cfg,
p += scnprintf(p, end - p, "random:");
- switch (get_random_u32_below(4)) {
+ switch (prandom_u32_below(rng, 4)) {
case 0:
case 1:
cfg->inplace_mode = OUT_OF_PLACE;
@@ -1058,12 +1100,12 @@ static void generate_random_testvec_config(struct testvec_config *cfg,
break;
}
- if (get_random_u32_below(2) == 0) {
+ if (prandom_bool(rng)) {
cfg->req_flags |= CRYPTO_TFM_REQ_MAY_SLEEP;
p += scnprintf(p, end - p, " may_sleep");
}
- switch (get_random_u32_below(4)) {
+ switch (prandom_u32_below(rng, 4)) {
case 0:
cfg->finalization_type = FINALIZATION_TYPE_FINAL;
p += scnprintf(p, end - p, " use_final");
@@ -1078,36 +1120,37 @@ static void generate_random_testvec_config(struct testvec_config *cfg,
break;
}
- if (!(cfg->req_flags & CRYPTO_TFM_REQ_MAY_SLEEP) &&
- get_random_u32_below(2) == 0) {
+ if (!(cfg->req_flags & CRYPTO_TFM_REQ_MAY_SLEEP) && prandom_bool(rng)) {
cfg->nosimd = true;
p += scnprintf(p, end - p, " nosimd");
}
p += scnprintf(p, end - p, " src_divs=[");
- p = generate_random_sgl_divisions(cfg->src_divs,
+ p = generate_random_sgl_divisions(rng, cfg->src_divs,
ARRAY_SIZE(cfg->src_divs), p, end,
(cfg->finalization_type !=
FINALIZATION_TYPE_DIGEST),
cfg->req_flags);
p += scnprintf(p, end - p, "]");
- if (cfg->inplace_mode == OUT_OF_PLACE && get_random_u32_below(2) == 0) {
+ if (cfg->inplace_mode == OUT_OF_PLACE && prandom_bool(rng)) {
p += scnprintf(p, end - p, " dst_divs=[");
- p = generate_random_sgl_divisions(cfg->dst_divs,
+ p = generate_random_sgl_divisions(rng, cfg->dst_divs,
ARRAY_SIZE(cfg->dst_divs),
p, end, false,
cfg->req_flags);
p += scnprintf(p, end - p, "]");
}
- if (get_random_u32_below(2) == 0) {
- cfg->iv_offset = get_random_u32_inclusive(1, MAX_ALGAPI_ALIGNMASK);
+ if (prandom_bool(rng)) {
+ cfg->iv_offset = prandom_u32_inclusive(rng, 1,
+ MAX_ALGAPI_ALIGNMASK);
p += scnprintf(p, end - p, " iv_offset=%u", cfg->iv_offset);
}
- if (get_random_u32_below(2) == 0) {
- cfg->key_offset = get_random_u32_inclusive(1, MAX_ALGAPI_ALIGNMASK);
+ if (prandom_bool(rng)) {
+ cfg->key_offset = prandom_u32_inclusive(rng, 1,
+ MAX_ALGAPI_ALIGNMASK);
p += scnprintf(p, end - p, " key_offset=%u", cfg->key_offset);
}
@@ -1620,11 +1663,14 @@ static int test_hash_vec(const struct hash_testvec *vec, unsigned int vec_num,
#ifdef CONFIG_CRYPTO_MANAGER_EXTRA_TESTS
if (!noextratests) {
+ struct rnd_state rng;
struct testvec_config cfg;
char cfgname[TESTVEC_CONFIG_NAMELEN];
+ init_rnd_state(&rng);
+
for (i = 0; i < fuzz_iterations; i++) {
- generate_random_testvec_config(&cfg, cfgname,
+ generate_random_testvec_config(&rng, &cfg, cfgname,
sizeof(cfgname));
err = test_hash_vec_cfg(vec, vec_name, &cfg,
req, desc, tsgl, hashstate);
@@ -1642,15 +1688,16 @@ static int test_hash_vec(const struct hash_testvec *vec, unsigned int vec_num,
* Generate a hash test vector from the given implementation.
* Assumes the buffers in 'vec' were already allocated.
*/
-static void generate_random_hash_testvec(struct shash_desc *desc,
+static void generate_random_hash_testvec(struct rnd_state *rng,
+ struct shash_desc *desc,
struct hash_testvec *vec,
unsigned int maxkeysize,
unsigned int maxdatasize,
char *name, size_t max_namelen)
{
/* Data */
- vec->psize = generate_random_length(maxdatasize);
- generate_random_bytes((u8 *)vec->plaintext, vec->psize);
+ vec->psize = generate_random_length(rng, maxdatasize);
+ generate_random_bytes(rng, (u8 *)vec->plaintext, vec->psize);
/*
* Key: length in range [1, maxkeysize], but usually choose maxkeysize.
@@ -1660,9 +1707,9 @@ static void generate_random_hash_testvec(struct shash_desc *desc,
vec->ksize = 0;
if (maxkeysize) {
vec->ksize = maxkeysize;
- if (get_random_u32_below(4) == 0)
- vec->ksize = get_random_u32_inclusive(1, maxkeysize);
- generate_random_bytes((u8 *)vec->key, vec->ksize);
+ if (prandom_u32_below(rng, 4) == 0)
+ vec->ksize = prandom_u32_inclusive(rng, 1, maxkeysize);
+ generate_random_bytes(rng, (u8 *)vec->key, vec->ksize);
vec->setkey_error = crypto_shash_setkey(desc->tfm, vec->key,
vec->ksize);
@@ -1696,6 +1743,7 @@ static int test_hash_vs_generic_impl(const char *generic_driver,
const unsigned int maxdatasize = (2 * PAGE_SIZE) - TESTMGR_POISON_LEN;
const char *algname = crypto_hash_alg_common(tfm)->base.cra_name;
const char *driver = crypto_ahash_driver_name(tfm);
+ struct rnd_state rng;
char _generic_driver[CRYPTO_MAX_ALG_NAME];
struct crypto_shash *generic_tfm = NULL;
struct shash_desc *generic_desc = NULL;
@@ -1709,6 +1757,8 @@ static int test_hash_vs_generic_impl(const char *generic_driver,
if (noextratests)
return 0;
+ init_rnd_state(&rng);
+
if (!generic_driver) { /* Use default naming convention? */
err = build_generic_driver_name(algname, _generic_driver);
if (err)
@@ -1777,10 +1827,11 @@ static int test_hash_vs_generic_impl(const char *generic_driver,
}
for (i = 0; i < fuzz_iterations * 8; i++) {
- generate_random_hash_testvec(generic_desc, &vec,
+ generate_random_hash_testvec(&rng, generic_desc, &vec,
maxkeysize, maxdatasize,
vec_name, sizeof(vec_name));
- generate_random_testvec_config(cfg, cfgname, sizeof(cfgname));
+ generate_random_testvec_config(&rng, cfg, cfgname,
+ sizeof(cfgname));
err = test_hash_vec_cfg(&vec, vec_name, cfg,
req, desc, tsgl, hashstate);
@@ -2182,11 +2233,14 @@ static int test_aead_vec(int enc, const struct aead_testvec *vec,
#ifdef CONFIG_CRYPTO_MANAGER_EXTRA_TESTS
if (!noextratests) {
+ struct rnd_state rng;
struct testvec_config cfg;
char cfgname[TESTVEC_CONFIG_NAMELEN];
+ init_rnd_state(&rng);
+
for (i = 0; i < fuzz_iterations; i++) {
- generate_random_testvec_config(&cfg, cfgname,
+ generate_random_testvec_config(&rng, &cfg, cfgname,
sizeof(cfgname));
err = test_aead_vec_cfg(enc, vec, vec_name,
&cfg, req, tsgls);
@@ -2202,6 +2256,7 @@ static int test_aead_vec(int enc, const struct aead_testvec *vec,
#ifdef CONFIG_CRYPTO_MANAGER_EXTRA_TESTS
struct aead_extra_tests_ctx {
+ struct rnd_state rng;
struct aead_request *req;
struct crypto_aead *tfm;
const struct alg_test_desc *test_desc;
@@ -2220,24 +2275,26 @@ struct aead_extra_tests_ctx {
* here means the full ciphertext including the authentication tag. The
* authentication tag (and hence also the ciphertext) is assumed to be nonempty.
*/
-static void mutate_aead_message(struct aead_testvec *vec, bool aad_iv,
+static void mutate_aead_message(struct rnd_state *rng,
+ struct aead_testvec *vec, bool aad_iv,
unsigned int ivsize)
{
const unsigned int aad_tail_size = aad_iv ? ivsize : 0;
const unsigned int authsize = vec->clen - vec->plen;
- if (get_random_u32_below(2) == 0 && vec->alen > aad_tail_size) {
+ if (prandom_bool(rng) && vec->alen > aad_tail_size) {
/* Mutate the AAD */
- flip_random_bit((u8 *)vec->assoc, vec->alen - aad_tail_size);
- if (get_random_u32_below(2) == 0)
+ flip_random_bit(rng, (u8 *)vec->assoc,
+ vec->alen - aad_tail_size);
+ if (prandom_bool(rng))
return;
}
- if (get_random_u32_below(2) == 0) {
+ if (prandom_bool(rng)) {
/* Mutate auth tag (assuming it's at the end of ciphertext) */
- flip_random_bit((u8 *)vec->ctext + vec->plen, authsize);
+ flip_random_bit(rng, (u8 *)vec->ctext + vec->plen, authsize);
} else {
/* Mutate any part of the ciphertext */
- flip_random_bit((u8 *)vec->ctext, vec->clen);
+ flip_random_bit(rng, (u8 *)vec->ctext, vec->clen);
}
}
@@ -2248,7 +2305,8 @@ static void mutate_aead_message(struct aead_testvec *vec, bool aad_iv,
*/
#define MIN_COLLISION_FREE_AUTHSIZE 8
-static void generate_aead_message(struct aead_request *req,
+static void generate_aead_message(struct rnd_state *rng,
+ struct aead_request *req,
const struct aead_test_suite *suite,
struct aead_testvec *vec,
bool prefer_inauthentic)
@@ -2257,17 +2315,18 @@ static void generate_aead_message(struct aead_request *req,
const unsigned int ivsize = crypto_aead_ivsize(tfm);
const unsigned int authsize = vec->clen - vec->plen;
const bool inauthentic = (authsize >= MIN_COLLISION_FREE_AUTHSIZE) &&
- (prefer_inauthentic || get_random_u32_below(4) == 0);
+ (prefer_inauthentic ||
+ prandom_u32_below(rng, 4) == 0);
/* Generate the AAD. */
- generate_random_bytes((u8 *)vec->assoc, vec->alen);
+ generate_random_bytes(rng, (u8 *)vec->assoc, vec->alen);
if (suite->aad_iv && vec->alen >= ivsize)
/* Avoid implementation-defined behavior. */
memcpy((u8 *)vec->assoc + vec->alen - ivsize, vec->iv, ivsize);
- if (inauthentic && get_random_u32_below(2) == 0) {
+ if (inauthentic && prandom_bool(rng)) {
/* Generate a random ciphertext. */
- generate_random_bytes((u8 *)vec->ctext, vec->clen);
+ generate_random_bytes(rng, (u8 *)vec->ctext, vec->clen);
} else {
int i = 0;
struct scatterlist src[2], dst;
@@ -2279,7 +2338,7 @@ static void generate_aead_message(struct aead_request *req,
if (vec->alen)
sg_set_buf(&src[i++], vec->assoc, vec->alen);
if (vec->plen) {
- generate_random_bytes((u8 *)vec->ptext, vec->plen);
+ generate_random_bytes(rng, (u8 *)vec->ptext, vec->plen);
sg_set_buf(&src[i++], vec->ptext, vec->plen);
}
sg_init_one(&dst, vec->ctext, vec->alen + vec->clen);
@@ -2299,7 +2358,7 @@ static void generate_aead_message(struct aead_request *req,
* Mutate the authentic (ciphertext, AAD) pair to get an
* inauthentic one.
*/
- mutate_aead_message(vec, suite->aad_iv, ivsize);
+ mutate_aead_message(rng, vec, suite->aad_iv, ivsize);
}
vec->novrfy = 1;
if (suite->einval_allowed)
@@ -2313,7 +2372,8 @@ static void generate_aead_message(struct aead_request *req,
* If 'prefer_inauthentic' is true, then this function will generate inauthentic
* test vectors (i.e. vectors with 'vec->novrfy=1') more often.
*/
-static void generate_random_aead_testvec(struct aead_request *req,
+static void generate_random_aead_testvec(struct rnd_state *rng,
+ struct aead_request *req,
struct aead_testvec *vec,
const struct aead_test_suite *suite,
unsigned int maxkeysize,
@@ -2329,18 +2389,18 @@ static void generate_random_aead_testvec(struct aead_request *req,
/* Key: length in [0, maxkeysize], but usually choose maxkeysize */
vec->klen = maxkeysize;
- if (get_random_u32_below(4) == 0)
- vec->klen = get_random_u32_below(maxkeysize + 1);
- generate_random_bytes((u8 *)vec->key, vec->klen);
+ if (prandom_u32_below(rng, 4) == 0)
+ vec->klen = prandom_u32_below(rng, maxkeysize + 1);
+ generate_random_bytes(rng, (u8 *)vec->key, vec->klen);
vec->setkey_error = crypto_aead_setkey(tfm, vec->key, vec->klen);
/* IV */
- generate_random_bytes((u8 *)vec->iv, ivsize);
+ generate_random_bytes(rng, (u8 *)vec->iv, ivsize);
/* Tag length: in [0, maxauthsize], but usually choose maxauthsize */
authsize = maxauthsize;
- if (get_random_u32_below(4) == 0)
- authsize = get_random_u32_below(maxauthsize + 1);
+ if (prandom_u32_below(rng, 4) == 0)
+ authsize = prandom_u32_below(rng, maxauthsize + 1);
if (prefer_inauthentic && authsize < MIN_COLLISION_FREE_AUTHSIZE)
authsize = MIN_COLLISION_FREE_AUTHSIZE;
if (WARN_ON(authsize > maxdatasize))
@@ -2349,11 +2409,11 @@ static void generate_random_aead_testvec(struct aead_request *req,
vec->setauthsize_error = crypto_aead_setauthsize(tfm, authsize);
/* AAD, plaintext, and ciphertext lengths */
- total_len = generate_random_length(maxdatasize);
- if (get_random_u32_below(4) == 0)
+ total_len = generate_random_length(rng, maxdatasize);
+ if (prandom_u32_below(rng, 4) == 0)
vec->alen = 0;
else
- vec->alen = generate_random_length(total_len);
+ vec->alen = generate_random_length(rng, total_len);
vec->plen = total_len - vec->alen;
vec->clen = vec->plen + authsize;
@@ -2364,7 +2424,7 @@ static void generate_random_aead_testvec(struct aead_request *req,
vec->novrfy = 0;
vec->crypt_error = 0;
if (vec->setkey_error == 0 && vec->setauthsize_error == 0)
- generate_aead_message(req, suite, vec, prefer_inauthentic);
+ generate_aead_message(rng, req, suite, vec, prefer_inauthentic);
snprintf(name, max_namelen,
"\"random: alen=%u plen=%u authsize=%u klen=%u novrfy=%d\"",
vec->alen, vec->plen, authsize, vec->klen, vec->novrfy);
@@ -2376,7 +2436,7 @@ static void try_to_generate_inauthentic_testvec(
int i;
for (i = 0; i < 10; i++) {
- generate_random_aead_testvec(ctx->req, &ctx->vec,
+ generate_random_aead_testvec(&ctx->rng, ctx->req, &ctx->vec,
&ctx->test_desc->suite.aead,
ctx->maxkeysize, ctx->maxdatasize,
ctx->vec_name,
@@ -2407,7 +2467,8 @@ static int test_aead_inauthentic_inputs(struct aead_extra_tests_ctx *ctx)
*/
try_to_generate_inauthentic_testvec(ctx);
if (ctx->vec.novrfy) {
- generate_random_testvec_config(&ctx->cfg, ctx->cfgname,
+ generate_random_testvec_config(&ctx->rng, &ctx->cfg,
+ ctx->cfgname,
sizeof(ctx->cfgname));
err = test_aead_vec_cfg(DECRYPT, &ctx->vec,
ctx->vec_name, &ctx->cfg,
@@ -2497,12 +2558,13 @@ static int test_aead_vs_generic_impl(struct aead_extra_tests_ctx *ctx)
* the other implementation against them.
*/
for (i = 0; i < fuzz_iterations * 8; i++) {
- generate_random_aead_testvec(generic_req, &ctx->vec,
+ generate_random_aead_testvec(&ctx->rng, generic_req, &ctx->vec,
&ctx->test_desc->suite.aead,
ctx->maxkeysize, ctx->maxdatasize,
ctx->vec_name,
sizeof(ctx->vec_name), false);
- generate_random_testvec_config(&ctx->cfg, ctx->cfgname,
+ generate_random_testvec_config(&ctx->rng, &ctx->cfg,
+ ctx->cfgname,
sizeof(ctx->cfgname));
if (!ctx->vec.novrfy) {
err = test_aead_vec_cfg(ENCRYPT, &ctx->vec,
@@ -2541,6 +2603,7 @@ static int test_aead_extra(const struct alg_test_desc *test_desc,
ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
if (!ctx)
return -ENOMEM;
+ init_rnd_state(&ctx->rng);
ctx->req = req;
ctx->tfm = crypto_aead_reqtfm(req);
ctx->test_desc = test_desc;
@@ -2930,11 +2993,14 @@ static int test_skcipher_vec(int enc, const struct cipher_testvec *vec,
#ifdef CONFIG_CRYPTO_MANAGER_EXTRA_TESTS
if (!noextratests) {
+ struct rnd_state rng;
struct testvec_config cfg;
char cfgname[TESTVEC_CONFIG_NAMELEN];
+ init_rnd_state(&rng);
+
for (i = 0; i < fuzz_iterations; i++) {
- generate_random_testvec_config(&cfg, cfgname,
+ generate_random_testvec_config(&rng, &cfg, cfgname,
sizeof(cfgname));
err = test_skcipher_vec_cfg(enc, vec, vec_name,
&cfg, req, tsgls);
@@ -2952,7 +3018,8 @@ static int test_skcipher_vec(int enc, const struct cipher_testvec *vec,
* Generate a symmetric cipher test vector from the given implementation.
* Assumes the buffers in 'vec' were already allocated.
*/
-static void generate_random_cipher_testvec(struct skcipher_request *req,
+static void generate_random_cipher_testvec(struct rnd_state *rng,
+ struct skcipher_request *req,
struct cipher_testvec *vec,
unsigned int maxdatasize,
char *name, size_t max_namelen)
@@ -2966,17 +3033,17 @@ static void generate_random_cipher_testvec(struct skcipher_request *req,
/* Key: length in [0, maxkeysize], but usually choose maxkeysize */
vec->klen = maxkeysize;
- if (get_random_u32_below(4) == 0)
- vec->klen = get_random_u32_below(maxkeysize + 1);
- generate_random_bytes((u8 *)vec->key, vec->klen);
+ if (prandom_u32_below(rng, 4) == 0)
+ vec->klen = prandom_u32_below(rng, maxkeysize + 1);
+ generate_random_bytes(rng, (u8 *)vec->key, vec->klen);
vec->setkey_error = crypto_skcipher_setkey(tfm, vec->key, vec->klen);
/* IV */
- generate_random_bytes((u8 *)vec->iv, ivsize);
+ generate_random_bytes(rng, (u8 *)vec->iv, ivsize);
/* Plaintext */
- vec->len = generate_random_length(maxdatasize);
- generate_random_bytes((u8 *)vec->ptext, vec->len);
+ vec->len = generate_random_length(rng, maxdatasize);
+ generate_random_bytes(rng, (u8 *)vec->ptext, vec->len);
/* If the key couldn't be set, no need to continue to encrypt. */
if (vec->setkey_error)
@@ -3018,6 +3085,7 @@ static int test_skcipher_vs_generic_impl(const char *generic_driver,
const unsigned int maxdatasize = (2 * PAGE_SIZE) - TESTMGR_POISON_LEN;
const char *algname = crypto_skcipher_alg(tfm)->base.cra_name;
const char *driver = crypto_skcipher_driver_name(tfm);
+ struct rnd_state rng;
char _generic_driver[CRYPTO_MAX_ALG_NAME];
struct crypto_skcipher *generic_tfm = NULL;
struct skcipher_request *generic_req = NULL;
@@ -3035,6 +3103,8 @@ static int test_skcipher_vs_generic_impl(const char *generic_driver,
if (strncmp(algname, "kw(", 3) == 0)
return 0;
+ init_rnd_state(&rng);
+
if (!generic_driver) { /* Use default naming convention? */
err = build_generic_driver_name(algname, _generic_driver);
if (err)
@@ -3119,9 +3189,11 @@ static int test_skcipher_vs_generic_impl(const char *generic_driver,
}
for (i = 0; i < fuzz_iterations * 8; i++) {
- generate_random_cipher_testvec(generic_req, &vec, maxdatasize,
+ generate_random_cipher_testvec(&rng, generic_req, &vec,
+ maxdatasize,
vec_name, sizeof(vec_name));
- generate_random_testvec_config(cfg, cfgname, sizeof(cfgname));
+ generate_random_testvec_config(&rng, cfg, cfgname,
+ sizeof(cfgname));
err = test_skcipher_vec_cfg(ENCRYPT, &vec, vec_name,
cfg, req, tsgls);
base-commit: 2fcd07b7ccd5fd10b2120d298363e4e6c53ccf9c
--
2.39.2
On Mon, Feb 27, 2023 at 7:30 PM Eric Biggers <[email protected]> wrote:
>
> From: Eric Biggers <[email protected]>
>
> The performance of the crypto fuzz tests has greatly regressed since
> v5.18. When booting a kernel on an arm64 dev board with all software
> crypto algorithms and CONFIG_CRYPTO_MANAGER_EXTRA_TESTS enabled, the
> fuzz tests now take about 200 seconds to run, or about 325 seconds with
> lockdep enabled, compared to about 5 seconds before.
>
> The root cause is that the random number generation has become much
> slower due to commit d4150779e60f ("random32: use real rng for
> non-deterministic randomness"). On my same arm64 dev board, at the time
> the fuzz tests are run, get_random_u8() is about 345x slower than
> prandom_u32_state(), or about 469x if lockdep is enabled.
>
> Lockdep makes a big difference, but much of the rest comes from the
> get_random_*() functions taking a *very* slow path when the CRNG is not
> yet initialized. Since the crypto self-tests run early during boot,
> even having a hardware RNG driver enabled (CONFIG_CRYPTO_DEV_QCOM_RNG in
> my case) doesn't prevent this. x86 systems don't have this issue, but
> they still see a significant regression if lockdep is enabled.
>
> Converting the "Fully random bytes" case in generate_random_bytes() to
> use get_random_bytes() helps significantly, improving the test time to
> about 27 seconds. But that's still over 5x slower than before.
>
> This is all a bit silly, though, since the fuzz tests don't actually
> need cryptographically secure random numbers. So let's just make them
> use a non-cryptographically-secure RNG as they did before. The original
> prandom_u32() is gone now, so let's use prandom_u32_state() instead,
> with an explicitly managed state, like various other self-tests in the
> kernel source tree (rbtree_test.c, test_scanf.c, etc.) already do. This
> also has the benefit that no locking is required anymore, so performance
> should be even better than the original version that used prandom_u32().
>
> Fixes: d4150779e60f ("random32: use real rng for non-deterministic randomness")
> Cc: [email protected]
> Signed-off-by: Eric Biggers <[email protected]>
> ---
>
> v2: made init_rnd_state() use get_random_u64()
>
> crypto/testmgr.c | 266 ++++++++++++++++++++++++++++++-----------------
> 1 file changed, 169 insertions(+), 97 deletions(-)
>
> diff --git a/crypto/testmgr.c b/crypto/testmgr.c
> index c91e93ece20b..b160eeb12c8e 100644
> --- a/crypto/testmgr.c
> +++ b/crypto/testmgr.c
> @@ -860,12 +860,50 @@ static int prepare_keybuf(const u8 *key, unsigned int ksize,
>
> #ifdef CONFIG_CRYPTO_MANAGER_EXTRA_TESTS
>
> +/*
> + * The fuzz tests use prandom instead of the normal Linux RNG since they don't
> + * need cryptographically secure random numbers. This greatly improves the
> + * performance of these tests, especially if they are run before the Linux RNG
> + * has been initialized or if they are run on a lockdep-enabled kernel.
> + */
> +
> +static inline void init_rnd_state(struct rnd_state *rng)
> +{
> + prandom_seed_state(rng, get_random_u64());
i915 does something similar and prints it out with `kunit_info(suite,
"Testing DRM buddy manager, with random_seed=0x%x\n", random_seed);`,
so that you can repeat the test if necessary. Not saying you have to
do this now, but it may be a cool feature to keep in mind for the
future.
Jason
On Mon, Feb 27, 2023 at 10:29:47AM -0800, Eric Biggers wrote:
> From: Eric Biggers <[email protected]>
>
> The performance of the crypto fuzz tests has greatly regressed since
> v5.18. When booting a kernel on an arm64 dev board with all software
> crypto algorithms and CONFIG_CRYPTO_MANAGER_EXTRA_TESTS enabled, the
> fuzz tests now take about 200 seconds to run, or about 325 seconds with
> lockdep enabled, compared to about 5 seconds before.
>
> The root cause is that the random number generation has become much
> slower due to commit d4150779e60f ("random32: use real rng for
> non-deterministic randomness"). On my same arm64 dev board, at the time
> the fuzz tests are run, get_random_u8() is about 345x slower than
> prandom_u32_state(), or about 469x if lockdep is enabled.
>
> Lockdep makes a big difference, but much of the rest comes from the
> get_random_*() functions taking a *very* slow path when the CRNG is not
> yet initialized. Since the crypto self-tests run early during boot,
> even having a hardware RNG driver enabled (CONFIG_CRYPTO_DEV_QCOM_RNG in
> my case) doesn't prevent this. x86 systems don't have this issue, but
> they still see a significant regression if lockdep is enabled.
>
> Converting the "Fully random bytes" case in generate_random_bytes() to
> use get_random_bytes() helps significantly, improving the test time to
> about 27 seconds. But that's still over 5x slower than before.
>
> This is all a bit silly, though, since the fuzz tests don't actually
> need cryptographically secure random numbers. So let's just make them
> use a non-cryptographically-secure RNG as they did before. The original
> prandom_u32() is gone now, so let's use prandom_u32_state() instead,
> with an explicitly managed state, like various other self-tests in the
> kernel source tree (rbtree_test.c, test_scanf.c, etc.) already do. This
> also has the benefit that no locking is required anymore, so performance
> should be even better than the original version that used prandom_u32().
>
> Fixes: d4150779e60f ("random32: use real rng for non-deterministic randomness")
> Cc: [email protected]
> Signed-off-by: Eric Biggers <[email protected]>
> ---
>
> v2: made init_rnd_state() use get_random_u64()
>
> crypto/testmgr.c | 266 ++++++++++++++++++++++++++++++-----------------
> 1 file changed, 169 insertions(+), 97 deletions(-)
Patch applied. Thanks.
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt