[reactos] 04/12: [WIN32K] Add some validity checks in PDEVOBJ_vReference() and use it instead of explicitly manipulating ppdev->cPdevRefs.

[Hermès Bélusca-Maïto]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=148e137b421587abfa0ca9...

commit 148e137b421587abfa0ca987cb12a51d267a62d7
Author:     Hermès Bélusca-Maïto [e-mail]
AuthorDate: Sun Nov 24 21:22:21 2019 +0100
Commit:     Hermès Bélusca-Maïto [e-mail]
CommitDate: Mon Nov 25 00:41:51 2019 +0100

[WIN32K] Add some validity checks in PDEVOBJ_vReference() and use it instead of explicitly manipulating ppdev->cPdevRefs.
---
 win32ss/gdi/eng/pdevobj.c   |  2 +-
 win32ss/gdi/eng/pdevobj.h   | 25 ++++++++++++++++++-------
 win32ss/gdi/ntgdi/dclife.c  |  2 +-
 win32ss/gdi/ntgdi/dcstate.c |  2 +-
 4 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/win32ss/gdi/eng/pdevobj.c b/win32ss/gdi/eng/pdevobj.c
index 450d37f6785..4147f0fa749 100644
--- a/win32ss/gdi/eng/pdevobj.c
+++ b/win32ss/gdi/eng/pdevobj.c
@@ -630,7 +630,7 @@ EngpGetPDEV(
     if (ppdev)
     {
         /* Yes, reference the PDEV */
-        InterlockedIncrement(&ppdev->cPdevRefs);
+        PDEVOBJ_vReference(ppdev);
     }
     else
     {
diff --git a/win32ss/gdi/eng/pdevobj.h b/win32ss/gdi/eng/pdevobj.h
index 9b986acde13..a232a2e057c 100644
--- a/win32ss/gdi/eng/pdevobj.h
+++ b/win32ss/gdi/eng/pdevobj.h
@@ -162,6 +162,24 @@ NTAPI
 EngpGetPDEV(
     _In_opt_ PUNICODE_STRING pustrDevice);

+FORCEINLINE
+VOID
+PDEVOBJ_vReference(
+    _In_ PPDEVOBJ ppdev)
+{
+    ASSERT(ppdev);
+
+    /* Fail if the PDEV is being destroyed */
+    if (ppdev->cPdevRefs == 0)
+    {
+        ASSERT(FALSE);
+        return;
+    }
+    ASSERT(ppdev->cPdevRefs > 0);
+
+    InterlockedIncrement(&ppdev->cPdevRefs);
+}
+
 VOID
 NTAPI
 PDEVOBJ_vRelease(
@@ -201,11 +219,4 @@ PDEVOBJ_pdmMatchDevMode(
     PPDEVOBJ ppdev,
     PDEVMODEW pdm);

-FORCEINLINE
-VOID
-PDEVOBJ_vReference(PPDEVOBJ ppdev)
-{
-    InterlockedIncrement(&ppdev->cPdevRefs);
-}
-
 #endif /* !__WIN32K_PDEVOBJ_H */
diff --git a/win32ss/gdi/ntgdi/dclife.c b/win32ss/gdi/ntgdi/dclife.c
index 99d872a9c2f..52236c037c3 100644
--- a/win32ss/gdi/ntgdi/dclife.c
+++ b/win32ss/gdi/ntgdi/dclife.c
@@ -836,7 +836,7 @@ GreCreateCompatibleDC(HDC hdc, BOOL bAltDc)

/* Get the pdev from the DC */
         ppdev = pdc->ppdev;
-        InterlockedIncrement(&ppdev->cPdevRefs);
+        PDEVOBJ_vReference(ppdev);

/* Unlock the source DC */
         DC_UnlockDc(pdc);
diff --git a/win32ss/gdi/ntgdi/dcstate.c b/win32ss/gdi/ntgdi/dcstate.c
index ccf7c134e7f..314eaa6c380 100644
--- a/win32ss/gdi/ntgdi/dcstate.c
+++ b/win32ss/gdi/ntgdi/dcstate.c
@@ -282,7 +282,7 @@ NtGdiSaveDC(
     }
     hdcSave = pdcSave->BaseObject.hHmgr;

-    InterlockedIncrement(&pdc->ppdev->cPdevRefs);
+    PDEVOBJ_vReference(pdc->ppdev);
     DC_vInitDc(pdcSave, DCTYPE_MEMORY, pdc->ppdev);

/* Handle references here correctly */