rand: note that locking needs to be explicitly enabled.

Fixes #13912

Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/14224)

diff --git a/doc/man3/EVP_RAND.pod b/doc/man3/EVP_RAND.pod
index c2940a3455f086f9d8f685b608e4838bb9642d9c..97114af0fb99eac65fbf5c011a0bfae5417d828b 100644 (file)
--- a/doc/man3/EVP_RAND.pod
+++ b/doc/man3/EVP_RAND.pod
@@ -311,6 +311,12 @@ or the properties in the case of B<OSSL_RAND_PARAM_PROPERTIES>.
 
 =back
 
+=head1 NOTES
+
+An B<EVP_RAND_CTX> needs to have locking enabled if it acts as the parent of
+more than one child and the children can be accessed concurrently.  This must
+be done by explicitly calling EVP_RAND_enable_locking().
+
 =head1 RETURN VALUES
 
 EVP_RAND_fetch() returns a pointer to a newly fetched B<EVP_RAND>, or