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add locking around fake_now
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fake_now in the quictestlib is read/written by potentially many threads,
and as such should have a surrounding lock to prevent WAR/RAW errors as
caught by tsan:

2023-11-03T16:27:23.7184999Z ==================
2023-11-03T16:27:23.7185290Z WARNING: ThreadSanitizer: data race (pid=18754)
2023-11-03T16:27:23.7185720Z   Read of size 8 at 0x558f6f9fe970 by main thread:
2023-11-03T16:27:23.7186726Z     #0 qtest_create_quic_connection_ex <null> (quicapitest+0x14aead) (BuildId: d06f7b04830b55de9c8482b398a1781472d1c7d5)
2023-11-03T16:27:23.7187665Z     #1 qtest_create_quic_connection <null> (quicapitest+0x14b220) (BuildId: d06f7b04830b55de9c8482b398a1781472d1c7d5)
2023-11-03T16:27:23.7188567Z     #2 test_quic_write_read quicapitest.c (quicapitest+0x150ee2) (BuildId: d06f7b04830b55de9c8482b398a1781472d1c7d5)
2023-11-03T16:27:23.7189561Z     #3 run_tests <null> (quicapitest+0x2237ab) (BuildId: d06f7b04830b55de9c8482b398a1781472d1c7d5)
2023-11-03T16:27:23.7190294Z     #4 main <null> (quicapitest+0x223d2b) (BuildId: d06f7b04830b55de9c8482b398a1781472d1c7d5)
2023-11-03T16:27:23.7190720Z
2023-11-03T16:27:23.7190902Z   Previous write of size 8 at 0x558f6f9fe970 by thread T1:
2023-11-03T16:27:23.7191607Z     #0 qtest_create_quic_connection_ex <null> (quicapitest+0x14aecf) (BuildId: d06f7b04830b55de9c8482b398a1781472d1c7d5)
2023-11-03T16:27:23.7192505Z     #1 run_server_thread quictestlib.c (quicapitest+0x14b1d6) (BuildId: d06f7b04830b55de9c8482b398a1781472d1c7d5)
2023-11-03T16:27:23.7193361Z     #2 thread_run quictestlib.c (quicapitest+0x14cadf) (BuildId: d06f7b04830b55de9c8482b398a1781472d1c7d5)
2023-11-03T16:27:23.7193848Z
2023-11-03T16:27:23.7194220Z   Location is global 'fake_now.0' of size 8 at 0x558f6f9fe970 (quicapitest+0x1af4970)
2023-11-03T16:27:23.7194636Z
2023-11-03T16:27:23.7194816Z   Thread T1 (tid=18760, running) created by main thread at:
2023-11-03T16:27:23.7195465Z     #0 pthread_create <null> (quicapitest+0xca12d) (BuildId: d06f7b04830b55de9c8482b398a1781472d1c7d5)
2023-11-03T16:27:23.7196317Z     #1 qtest_create_quic_connection_ex <null> (quicapitest+0x14adcb) (BuildId: d06f7b04830b55de9c8482b398a1781472d1c7d5)
2023-11-03T16:27:23.7197214Z     #2 qtest_create_quic_connection <null> (quicapitest+0x14b220) (BuildId: d06f7b04830b55de9c8482b398a1781472d1c7d5)
2023-11-03T16:27:23.7198111Z     #3 test_quic_write_read quicapitest.c (quicapitest+0x150ee2) (BuildId: d06f7b04830b55de9c8482b398a1781472d1c7d5)
2023-11-03T16:27:23.7198940Z     #4 run_tests <null> (quicapitest+0x2237ab) (BuildId: d06f7b04830b55de9c8482b398a1781472d1c7d5)
2023-11-03T16:27:23.7199661Z     #5 main <null> (quicapitest+0x223d2b) (BuildId: d06f7b04830b55de9c8482b398a1781472d1c7d5)
2023-11-03T16:27:23.7200083Z
2023-11-03T16:27:23.7200862Z SUMMARY: ThreadSanitizer: data race (/home/runner/work/openssl/openssl/test/quicapitest+0x14aead) (BuildId: d06f7b04830b55de9c8482b398a1781472d1c7d5) in qtest_create_quic_connection_ex

Reviewed-by: Hugo Landau <hlandau@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from openssl#22616)
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nhorman authored and t8m committed Nov 8, 2023
1 parent 22b482a commit 11179b3
Showing 1 changed file with 39 additions and 6 deletions.
45 changes: 39 additions & 6 deletions test/helpers/quictestlib.c
Original file line number Diff line number Diff line change
Expand Up @@ -74,13 +74,16 @@ struct qtest_fault {

static void packet_plain_finish(void *arg);
static void handshake_finish(void *arg);
static OSSL_TIME qtest_get_time(void);
static void qtest_reset_time(void);

static int using_fake_time = 0;
static OSSL_TIME fake_now;
static CRYPTO_RWLOCK *fake_now_lock = NULL;

static OSSL_TIME fake_now_cb(void *arg)
{
return fake_now;
return qtest_get_time();
}

static void noise_msg_callback(int write_p, int version, int content_type,
Expand Down Expand Up @@ -282,11 +285,14 @@ int qtest_create_quic_objects(OSSL_LIB_CTX *libctx, SSL_CTX *clientctx,
if (serverctx != NULL && !TEST_true(SSL_CTX_up_ref(serverctx)))
goto err;
tserver_args.ctx = serverctx;
if (fake_now_lock == NULL) {
fake_now_lock = CRYPTO_THREAD_lock_new();
if (fake_now_lock == NULL)
goto err;
}
if ((flags & QTEST_FLAG_FAKE_TIME) != 0) {
using_fake_time = 1;
fake_now = ossl_time_zero();
/* zero time can have a special meaning, bump it */
qtest_add_time(1);
qtest_reset_time();
tserver_args.now_cb = fake_now_cb;
(void)ossl_quic_conn_set_override_now_cb(*cssl, fake_now_cb, NULL);
} else {
Expand Down Expand Up @@ -331,7 +337,31 @@ int qtest_create_quic_objects(OSSL_LIB_CTX *libctx, SSL_CTX *clientctx,

void qtest_add_time(uint64_t millis)
{
if (!CRYPTO_THREAD_write_lock(fake_now_lock))
return;
fake_now = ossl_time_add(fake_now, ossl_ms2time(millis));
CRYPTO_THREAD_unlock(fake_now_lock);
}

static OSSL_TIME qtest_get_time(void)
{
OSSL_TIME ret;

if (!CRYPTO_THREAD_read_lock(fake_now_lock))
return ossl_time_zero();
ret = fake_now;
CRYPTO_THREAD_unlock(fake_now_lock);
return ret;
}

static void qtest_reset_time(void)
{
if (!CRYPTO_THREAD_write_lock(fake_now_lock))
return;
fake_now = ossl_time_zero();
CRYPTO_THREAD_unlock(fake_now_lock);
/* zero time can have a special meaning, bump it */
qtest_add_time(1);
}

QTEST_FAULT *qtest_create_injector(QUIC_TSERVER *ts)
Expand Down Expand Up @@ -399,17 +429,20 @@ int qtest_wait_for_timeout(SSL *s, QUIC_TSERVER *qtserv)
*/
if (!SSL_get_event_timeout(s, &tv, &cinf))
return 0;

if (using_fake_time)
now = fake_now;
now = qtest_get_time();
else
now = ossl_time_now();

ctimeout = cinf ? ossl_time_infinite() : ossl_time_from_timeval(tv);
stimeout = ossl_time_subtract(ossl_quic_tserver_get_deadline(qtserv), now);
mintimeout = ossl_time_min(ctimeout, stimeout);
if (ossl_time_is_infinite(mintimeout))
return 0;

if (using_fake_time)
fake_now = ossl_time_add(now, mintimeout);
qtest_add_time(ossl_time2ms(mintimeout));
else
OSSL_sleep(ossl_time2ms(mintimeout));

Expand Down

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