[PATCH v2 0/1] MR4323: pdh: Introduce memory barrier in destroy operations.

[eric pouech (＠epo)]

gcc tends to optimize away the magic field cleanup, leading to
believe the query is still allocated.

Signed-off-by: Eric Pouech <epouech(a)codeweavers.com>

--
  v2: pdh: Zero out magic fields with SecureZeroMemory().
 
https://gitlab.winehq.org/wine/wine/-/merge_requests/4323

[PATCH v2 1/1] pdh: Zero out magic fields with SecureZeroMemory().

[Eric Pouech]

From: Eric Pouech <epouech(a)codeweavers.com>

gcc tends to optimize away the magic field cleanup, leading to
believe the query is still allocated.

Signed-off-by: Eric Pouech <epouech(a)codeweavers.com>
---
 dlls/pdh/pdh_main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/dlls/pdh/pdh_main.c b/dlls/pdh/pdh_main.c
index 073a74e1b52..a63c18e0bb4 100644
--- a/dlls/pdh/pdh_main.c
+++ b/dlls/pdh/pdh_main.c
@@ -97,7 +97,7 @@ static struct counter *create_counter( void )
 
 static void destroy_counter( struct counter *counter )
 {
-    counter->magic = 0;
+    SecureZeroMemory( &counter->magic, sizeof( counter->magic ) );
     free( counter->path );
     free( counter );
 }
@@ -130,7 +130,7 @@ static struct query *create_query( void )
 
 static void destroy_query( struct query *query )
 {
-    query->magic = 0;
+    SecureZeroMemory( &query->magic, sizeof( query->magic ) );
     free( query );
 }
 
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/4323

[eric pouech (＠epo)]

On Tue Nov  7 09:31:12 2023 +0000, Hans Leidekker wrote:
> We use [Rtl]SecureZeroMemory() elsewhere.
> V2 pushed

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/4323#note_51281

[Zebediah Figura (＠zfigura)]

Can we please have a comment in the code explaining why that's there?

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/4323#note_51347