Latest update - pre9

crypto/x509v3/v3_purp.c

@@ -13,6 +13,7 @@
 #include <openssl/x509v3.h>
 #include <openssl/x509_vfy.h>
 #include "internal/x509_int.h"
+#include "internal/tsan_assist.h"
 
 static void x509v3_cache_extensions(X509 *x);
 
@@ -133,13 +134,14 @@ int X509_PURPOSE_get_by_id(int purpose)
 {
     X509_PURPOSE tmp;
     int idx;
+
     if ((purpose >= X509_PURPOSE_MIN) && (purpose <= X509_PURPOSE_MAX))
         return purpose - X509_PURPOSE_MIN;
-    tmp.purpose = purpose;
-    if (!xptable)
+    if (xptable == NULL)
         return -1;
+    tmp.purpose = purpose;
     idx = sk_X509_PURPOSE_find(xptable, &tmp);
-    if (idx == -1)
+    if (idx < 0)
         return -1;
     return idx + X509_PURPOSE_COUNT;
 }
@@ -350,10 +352,10 @@ static void x509v3_cache_extensions(X509 *x)
     ASN1_BIT_STRING *ns;
     EXTENDED_KEY_USAGE *extusage;
     X509_EXTENSION *ex;
-
     int i;
 
-    if (x->ex_flags & EXFLAG_SET)
+    /* fast lock-free check, see end of the function for details. */
+    if (tsan_load((TSAN_QUALIFIER int *)&x->ex_cached))
         return;
 
     CRYPTO_THREAD_write_lock(x->lock);
@@ -497,6 +499,12 @@ static void x509v3_cache_extensions(X509 *x)
     x509_init_sig_info(x);
     x->ex_flags |= EXFLAG_SET;
     CRYPTO_THREAD_unlock(x->lock);
+    /*
+     * It has to be placed after memory barrier, which is implied by unlock.
+     * Worst thing that can happen is that another thread proceeds to lock
+     * and checks x->ex_flags & EXFLAGS_SET. See beginning of the function.
+     */
+    tsan_store((TSAN_QUALIFIER int *)&x->ex_cached, 1);
 }
 
 /*-