[reactos] 01/01: [CSRSRV] Fix locking logic when destroying threads & processes

[Jérôme Gardou]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=7054cd10b17f602a0d695…

commit 7054cd10b17f602a0d6958e618ab327c5fdce3da
Author:     Jérôme Gardou <jerome.gardou(a)reactos.org>
AuthorDate: Tue Mar 23 18:15:23 2021 +0100
Commit:     Jérôme Gardou <zefklop(a)users.noreply.github.com>
CommitDate: Tue Mar 23 18:17:44 2021 +0100

    [CSRSRV] Fix locking logic when destroying threads & processes
---
 subsystems/win32/csrsrv/procsup.c  | 3 ++-
 subsystems/win32/csrsrv/thredsup.c | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/subsystems/win32/csrsrv/procsup.c b/subsystems/win32/csrsrv/procsup.c
index de9743cd6c2..c580328b1e8 100644
--- a/subsystems/win32/csrsrv/procsup.c
+++ b/subsystems/win32/csrsrv/procsup.c
@@ -167,8 +167,9 @@ CsrLockedDereferenceProcess(PCSR_PROCESS CsrProcess)
     {
         /* Call the generic cleanup code */
         DPRINT1("Should kill process: %p\n", CsrProcess);
-        CsrAcquireProcessLock();
         CsrProcessRefcountZero(CsrProcess);
+        /* Acquire again, the lock it was released in CsrProcessRefcountZero */
+        CsrAcquireProcessLock();
     }
 }
 
diff --git a/subsystems/win32/csrsrv/thredsup.c b/subsystems/win32/csrsrv/thredsup.c
index 678a468812c..9f674b4942f 100644
--- a/subsystems/win32/csrsrv/thredsup.c
+++ b/subsystems/win32/csrsrv/thredsup.c
@@ -474,8 +474,9 @@ CsrLockedDereferenceThread(IN PCSR_THREAD CsrThread)
     if (LockCount == 0)
     {
         /* Call the generic cleanup code */
-        CsrAcquireProcessLock();
         CsrThreadRefcountZero(CsrThread);
+        /* Acquire the lock again, it was released by CsrThreadRefcountZero */
+        CsrAcquireProcessLock();
     }
 }