Reduce size of BlindingCacheConcurrency test under TSAN.

When building with TSAN, having 2048 threads causes crypto_test to run
for more than 20 minutes (when I gave up), vs about two minutes
normally. This will remove our TSAN coverage (due to timeouts) unless we
trim the size of the test.

Change-Id: I381c77a8e9e09c49f3476c38993db40ffdac60d6
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/39346
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: David Benjamin <davidben@google.com>

crypto/fipsmodule/rsa/rsa_impl.c

diff --git a/crypto/fipsmodule/rsa/rsa_impl.c b/crypto/fipsmodule/rsa/rsa_impl.c
index 6fb8ce7..caa2eb4 100644
--- a/crypto/fipsmodule/rsa/rsa_impl.c
+++ b/crypto/fipsmodule/rsa/rsa_impl.c
@@ -345,7 +345,12 @@
 // MAX_BLINDINGS_PER_RSA defines the maximum number of cached BN_BLINDINGs per
 // RSA*. Then this limit is exceeded, BN_BLINDING objects will be created and
 // destroyed as needed.
+#if defined(OPNESSL_TSAN)
+// Smaller under TSAN so that the edge case can be hit with fewer threads.
+#define MAX_BLINDINGS_PER_RSA 2
+#else
 #define MAX_BLINDINGS_PER_RSA 1024
+#endif
 
 // rsa_blinding_get returns a BN_BLINDING to use with |rsa|. It does this by
 // allocating one of the cached BN_BLINDING objects in |rsa->blindings|. If

crypto/rsa_extra/rsa_test.cc

diff --git a/crypto/rsa_extra/rsa_test.cc b/crypto/rsa_extra/rsa_test.cc
index 4218cdb..0df21c0 100644
--- a/crypto/rsa_extra/rsa_test.cc
+++ b/crypto/rsa_extra/rsa_test.cc
@@ -1125,8 +1125,13 @@
       RSA_private_key_from_bytes(kKey1, sizeof(kKey1) - 1));
   ASSERT_TRUE(rsa);
 
+#if defined(OPENSSL_TSAN)
+  constexpr size_t kSignaturesPerThread = 10;
+  constexpr size_t kNumThreads = 10;
+#else
   constexpr size_t kSignaturesPerThread = 100;
   constexpr size_t kNumThreads = 2048;
+#endif
 
   const uint8_t kDummyHash[32] = {0};
   auto worker = [&] {