[PATCH 1/1] ntdll: Use load / acquire instruction to get pointer value in RtlRunOnceBeginInitialize

[Luca Bacci]

From: Luca Bacci

This is needed on architectures with weak memory models like ARM64.
---
 dlls/ntdll/sync.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/dlls/ntdll/sync.c b/dlls/ntdll/sync.c
index 522ce0a2142..8c4e2dbf79b 100644
--- a/dlls/ntdll/sync.c
+++ b/dlls/ntdll/sync.c
@@ -61,7 +61,7 @@ DWORD WINAPI RtlRunOnceBeginInitialize( RTL_RUN_ONCE *once, ULONG flags, void **
 {
     if (flags & RTL_RUN_ONCE_CHECK_ONLY)
     {
-        ULONG_PTR val = (ULONG_PTR)once->Ptr;
+        ULONG_PTR val = (ULONG_PTR)__atomic_load_n (&once->Ptr, __ATOMIC_ACQUIRE);

if (flags & RTL_RUN_ONCE_ASYNC) return STATUS_INVALID_PARAMETER;
         if ((val & 3) != 2) return STATUS_UNSUCCESSFUL;
@@ -71,7 +71,7 @@ DWORD WINAPI RtlRunOnceBeginInitialize( RTL_RUN_ONCE *once, ULONG flags, void **

for (;;)
     {
-        ULONG_PTR next, val = (ULONG_PTR)once->Ptr;
+        ULONG_PTR next, val = (ULONG_PTR)__atomic_load_n (&once->Ptr, __ATOMIC_ACQUIRE);

switch (val & 3)
         {