From: Bernd Edlinger <bernd.edlinger@hotmail.de>
Date: Fri, 21 Feb 2025 23:01:59 +0000 (+0100)
Subject: Fix support for windows atomics
X-Git-Tag: openssl-3.4.2~155
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e0db3e4bef954d4690018806b415228e141c0ca8;p=thirdparty%2Fopenssl.git

Fix support for windows atomics

Make CRYPTO_atomic_add consistent with
CRYPTO_atomic_load_int and set the
reader_idx under write_lock since there
is no CRYPTO_atomic_store_int.

Reviewed-by: Neil Horman <nhorman@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/26963)

(cherry picked from commit bcb8eae1afe243a7c514b988289b06b838764fb6)
---

diff --git a/crypto/threads_win.c b/crypto/threads_win.c
index b4208d26758..f687ad82f03 100644
--- a/crypto/threads_win.c
+++ b/crypto/threads_win.c
@@ -339,7 +339,13 @@ static struct rcu_qp *update_qp(CRYPTO_RCU_LOCK *lock, uint32_t *curr_id)
 
     /* update the reader index to be the prior qp */
     tmp = lock->current_alloc_idx;
+# if (defined(NO_INTERLOCKEDOR64))
+    CRYPTO_THREAD_write_lock(lock->rw_lock);
+    lock->reader_idx = tmp;
+    CRYPTO_THREAD_unlock(lock->rw_lock);
+# else
     InterlockedExchange((LONG volatile *)&lock->reader_idx, tmp);
+# endif
 
     /* wake up any waiters */
     ossl_crypto_condvar_broadcast(lock->alloc_signal);
@@ -606,9 +612,21 @@ int CRYPTO_THREAD_compare_id(CRYPTO_THREAD_ID a, CRYPTO_THREAD_ID b)
 
 int CRYPTO_atomic_add(int *val, int amount, int *ret, CRYPTO_RWLOCK *lock)
 {
+# if (defined(NO_INTERLOCKEDOR64))
+    if (lock == NULL || !CRYPTO_THREAD_write_lock(lock))
+        return 0;
+    *val += amount;
+    *ret = *val;
+
+    if (!CRYPTO_THREAD_unlock(lock))
+        return 0;
+
+    return 1;
+# else
     *ret = (int)InterlockedExchangeAdd((LONG volatile *)val, (LONG)amount)
         + amount;
     return 1;
+# endif
 }
 
 int CRYPTO_atomic_add64(uint64_t *val, uint64_t op, uint64_t *ret,