Rework composite overlay window code to fix several resource management bugs.

The composite overlay window code had several misunderstandings of the
workings of the X server, in particular error handling paths would often
double-free objects. Clean all of this up by using resource destruction as
the sole mechanism for freeing resource-based objects.
This commit is contained in:
Keith Packard 2008-05-04 21:52:58 -07:00
parent 6c1accce87
commit efa65a0317
5 changed files with 206 additions and 184 deletions

View File

@ -7,4 +7,5 @@ libcomposite_la_SOURCES = \
compext.c \
compint.h \
compinit.c \
compoverlay.c \
compwindow.c

View File

@ -54,10 +54,7 @@ static CARD8 CompositeReqCode;
static DevPrivateKey CompositeClientPrivateKey = &CompositeClientPrivateKey;
RESTYPE CompositeClientWindowType;
RESTYPE CompositeClientSubwindowsType;
static RESTYPE CompositeClientOverlayType;
static void deleteCompOverlayClient (CompOverlayClientPtr pOcToDel,
ScreenPtr pScreen);
RESTYPE CompositeClientOverlayType;
typedef struct _CompositeClient {
int major_version;
@ -107,19 +104,8 @@ static int
FreeCompositeClientOverlay (pointer value, XID ccwid)
{
CompOverlayClientPtr pOc = (CompOverlayClientPtr) value;
ScreenPtr pScreen = pOc->pScreen;
CompScreenPtr cs;
deleteCompOverlayClient(pOc, pScreen);
/* Unmap overlay window when there are no more clients using it */
cs = GetCompScreen(pScreen);
if (cs->pOverlayClients == NULL) {
if (cs->pOverlayWin != NULL) {
UnmapWindow(cs->pOverlayWin, FALSE);
}
}
compFreeOverlayClient (pOc);
return Success;
}
@ -304,137 +290,6 @@ ProcCompositeNameWindowPixmap (ClientPtr client)
}
/*
* Routines for manipulating the per-screen overlay clients list.
* This list indicates which clients have called GetOverlayWindow
* for this screen.
*/
/* Return the screen's overlay client list element for the given client */
static CompOverlayClientPtr
findCompOverlayClient (ClientPtr pClient, ScreenPtr pScreen)
{
CompScreenPtr cs = GetCompScreen(pScreen);
CompOverlayClientPtr pOc;
for (pOc = cs->pOverlayClients; pOc != NULL; pOc = pOc->pNext) {
if (pOc->pClient == pClient) {
return pOc;
}
}
return NULL;
}
static int
createCompOverlayClient (ClientPtr pClient, ScreenPtr pScreen)
{
CompScreenPtr cs = GetCompScreen(pScreen);
CompOverlayClientPtr pOc;
pOc = (CompOverlayClientPtr) xalloc(sizeof(CompOverlayClientRec));
if (pOc == NULL) {
return BadAlloc;
}
pOc->pClient = pClient;
pOc->pScreen = pScreen;
pOc->resource = FakeClientID(pClient->index);
pOc->pNext = cs->pOverlayClients;
cs->pOverlayClients = pOc;
/*
* Create a resource for this element so it can be deleted
* when the client goes away.
*/
if (!AddResource (pOc->resource, CompositeClientOverlayType,
(pointer) pOc)) {
xfree(pOc);
return BadAlloc;
}
return Success;
}
/*
* Delete the given overlay client list element from its screen list.
*/
static void
deleteCompOverlayClient (CompOverlayClientPtr pOcToDel, ScreenPtr pScreen)
{
CompScreenPtr cs = GetCompScreen(pScreen);
CompOverlayClientPtr pOc, pNext;
CompOverlayClientPtr pOcLast = NULL;
pOc = cs->pOverlayClients;
while (pOc != NULL) {
pNext = pOc->pNext;
if (pOc == pOcToDel) {
xfree(pOc);
if (pOcLast == NULL) {
cs->pOverlayClients = pNext;
} else {
pOcLast->pNext = pNext;
}
break;
}
pOcLast = pOc;
pOc = pNext;
}
}
/*
* Delete all the hide-counts list elements for this screen.
*/
void
deleteCompOverlayClientsForScreen (ScreenPtr pScreen)
{
CompScreenPtr cs = GetCompScreen(pScreen);
CompOverlayClientPtr pOc, pTmp;
pOc = cs->pOverlayClients;
while (pOc != NULL) {
pTmp = pOc->pNext;
FreeResource(pOc->resource, 0);
pOc = pTmp;
}
cs->pOverlayClients = NULL;
}
/*
** If necessary, create the overlay window. And map it
** Note: I found it excessively difficult to destroy this window
** during compCloseScreen; DeleteWindow can't be called because
** the input devices are already shut down. So we are going to
** just allocate an overlay window once per screen per X server
** invocation.
*/
static WindowPtr
createOverlayWindow (ScreenPtr pScreen)
{
int wid = FakeClientID(0);
WindowPtr pWin;
XID overrideRedirect = TRUE;
int result;
pWin = CreateWindow (
wid, WindowTable[pScreen->myNum],
0, 0, pScreen->width, pScreen->height, 0,
InputOutput, CWOverrideRedirect, &overrideRedirect,
WindowTable[pScreen->myNum]->drawable.depth,
serverClient, pScreen->rootVisual, &result);
if (pWin == NULL) {
return NULL;
}
if (!AddResource(wid, RT_WINDOW, (pointer)pWin)) {
DeleteWindow(pWin, None);
return NULL;
}
return pWin;
}
static int
ProcCompositeGetOverlayWindow (ClientPtr client)
{
@ -456,28 +311,31 @@ ProcCompositeGetOverlayWindow (ClientPtr client)
}
pScreen = pWin->drawable.pScreen;
/*
* Create an OverlayClient structure to mark this client's
* interest in the overlay window
*/
pOc = compCreateOverlayClient(pScreen, client);
if (pOc == NULL)
return BadAlloc;
/*
* Make sure the overlay window exists
*/
cs = GetCompScreen(pScreen);
if (cs->pOverlayWin == NULL) {
cs->pOverlayWin = createOverlayWindow(pScreen);
if (cs->pOverlayWin == NULL) {
if (cs->pOverlayWin == NULL)
if (!compCreateOverlayWindow(pScreen))
{
FreeResource (pOc->resource, RT_NONE);
return BadAlloc;
}
}
rc = XaceHook(XACE_RESOURCE_ACCESS, client, cs->pOverlayWin->drawable.id,
RT_WINDOW, cs->pOverlayWin, RT_NONE, NULL, DixGetAttrAccess);
if (rc != Success)
{
FreeResource (pOc->resource, RT_NONE);
return rc;
MapWindow(cs->pOverlayWin, serverClient);
/* Record that client is using this overlay window */
pOc = findCompOverlayClient(client, pScreen);
if (pOc == NULL) {
int ret = createCompOverlayClient(client, pScreen);
if (ret != Success) {
return ret;
}
}
rep.type = X_Reply;
@ -504,7 +362,6 @@ ProcCompositeReleaseOverlayWindow (ClientPtr client)
WindowPtr pWin;
ScreenPtr pScreen;
CompOverlayClientPtr pOc;
CompScreenPtr cs;
REQUEST_SIZE_MATCH(xCompositeReleaseOverlayWindowReq);
pWin = (WindowPtr) LookupIDByType (stuff->window, RT_WINDOW);
@ -519,18 +376,12 @@ ProcCompositeReleaseOverlayWindow (ClientPtr client)
* Has client queried a reference to the overlay window
* on this screen? If not, generate an error.
*/
pOc = findCompOverlayClient(client, pWin->drawable.pScreen);
if (pOc == NULL) {
pOc = compFindOverlayClient (pWin->drawable.pScreen, client);
if (pOc == NULL)
return BadMatch;
}
/* The delete function will free the client structure */
FreeResource (pOc->resource, 0);
cs = GetCompScreen(pScreen);
if (cs->pOverlayClients == NULL) {
UnmapWindow(cs->pOverlayWin, FALSE);
}
FreeResource (pOc->resource, RT_NONE);
return client->noClientException;
}

View File

@ -76,14 +76,6 @@ compCloseScreen (int index, ScreenPtr pScreen)
pScreen->CopyWindow = cs->CopyWindow;
pScreen->PositionWindow = cs->PositionWindow;
deleteCompOverlayClientsForScreen(pScreen);
/*
** Note: no need to call DeleteWindow; the server has
** already destroyed it.
*/
cs->pOverlayWin = NULL;
xfree (cs);
dixSetPrivate(&pScreen->devPrivates, CompScreenPrivateKey, NULL);
ret = (*pScreen->CloseScreen) (index, pScreen);
@ -122,11 +114,11 @@ compChangeWindowAttributes(WindowPtr pWin, unsigned long mask)
if (ret && (mask & CWBackingStore)) {
if (pWin->backingStore != NotUseful) {
compRedirectWindow(serverClient, pWin, CompositeRedirectAutomatic);
pWin->backStorage = TRUE;
pWin->backStorage = (pointer) (intptr_t) 1;
} else {
compUnredirectWindow(serverClient, pWin,
CompositeRedirectAutomatic);
pWin->backStorage = FALSE;
pWin->backStorage = NULL;
}
}
@ -380,6 +372,7 @@ compScreenInit (ScreenPtr pScreen)
return FALSE;
cs->damaged = FALSE;
cs->overlayWid = FakeClientID(0);
cs->pOverlayWin = NULL;
cs->pOverlayClients = NULL;

View File

@ -155,6 +155,7 @@ typedef struct _CompScreen {
VisualID *alternateVisuals;
WindowPtr pOverlayWin;
Window overlayWid;
CompOverlayClientPtr pOverlayClients;
} CompScreenRec, *CompScreenPtr;
@ -172,6 +173,7 @@ extern DevPrivateKey CompSubwindowsPrivateKey;
extern RESTYPE CompositeClientWindowType;
extern RESTYPE CompositeClientSubwindowsType;
extern RESTYPE CompositeClientOverlayType;
/*
* compalloc.c
@ -229,6 +231,25 @@ CompositeRegisterAlternateVisuals (ScreenPtr pScreen,
Bool
compScreenInit (ScreenPtr pScreen);
/*
* compoverlay.c
*/
void
compFreeOverlayClient (CompOverlayClientPtr pOcToDel);
CompOverlayClientPtr
compFindOverlayClient (ScreenPtr pScreen, ClientPtr pClient);
CompOverlayClientPtr
compCreateOverlayClient (ScreenPtr pScreen, ClientPtr pClient);
Bool
compCreateOverlayWindow (ScreenPtr pScreen);
void
compDestroyOverlayWindow (ScreenPtr pScreen);
/*
* compwindow.c
*/
@ -292,9 +313,6 @@ compCopyWindow (WindowPtr pWin, DDXPointRec ptOldOrg, RegionPtr prgnSrc);
void
compWindowUpdate (WindowPtr pWin);
void
deleteCompOverlayClientsForScreen (ScreenPtr pScreen);
WindowPtr
CompositeRealChildHead (WindowPtr pWin);

159
composite/compoverlay.c Normal file
View File

@ -0,0 +1,159 @@
/*
* Copyright © 2006 Sun Microsystems
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that
* copyright notice and this permission notice appear in supporting
* documentation, and that the name of Sun Microsystems not be used in
* advertising or publicity pertaining to distribution of the software without
* specific, written prior permission. Sun Microsystems makes no
* representations about the suitability of this software for any purpose. It
* is provided "as is" without express or implied warranty.
*
* SUN MICROSYSTEMS DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
* EVENT SHALL SUN MICROSYSTEMS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
* DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
* TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*
* Copyright © 2003 Keith Packard
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that
* copyright notice and this permission notice appear in supporting
* documentation, and that the name of Keith Packard not be used in
* advertising or publicity pertaining to distribution of the software without
* specific, written prior permission. Keith Packard makes no
* representations about the suitability of this software for any purpose. It
* is provided "as is" without express or implied warranty.
*
* KEITH PACKARD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
* EVENT SHALL KEITH PACKARD BE LIABLE FOR ANY SPECIAL, INDIRECT OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
* DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
* TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
#ifdef HAVE_DIX_CONFIG_H
#include <dix-config.h>
#endif
#include "compint.h"
#include "xace.h"
/*
* Delete the given overlay client list element from its screen list.
*/
void
compFreeOverlayClient (CompOverlayClientPtr pOcToDel)
{
ScreenPtr pScreen = pOcToDel->pScreen;
CompScreenPtr cs = GetCompScreen (pScreen);
CompOverlayClientPtr *pPrev, pOc;
for (pPrev = &cs->pOverlayClients; (pOc = *pPrev); pPrev = &pOc->pNext)
{
if (pOc == pOcToDel) {
*pPrev = pOc->pNext;
xfree (pOc);
break;
}
}
/* Destroy overlay window when there are no more clients using it */
if (cs->pOverlayClients == NULL)
compDestroyOverlayWindow (pScreen);
}
/*
* Return the client's first overlay client rec from the given screen
*/
CompOverlayClientPtr
compFindOverlayClient (ScreenPtr pScreen, ClientPtr pClient)
{
CompScreenPtr cs = GetCompScreen(pScreen);
CompOverlayClientPtr pOc;
for (pOc = cs->pOverlayClients; pOc != NULL; pOc = pOc->pNext)
if (pOc->pClient == pClient)
return pOc;
return NULL;
}
/*
* Create an overlay client object for the given client
*/
CompOverlayClientPtr
compCreateOverlayClient (ScreenPtr pScreen, ClientPtr pClient)
{
CompScreenPtr cs = GetCompScreen(pScreen);
CompOverlayClientPtr pOc;
pOc = (CompOverlayClientPtr) xalloc(sizeof(CompOverlayClientRec));
if (pOc == NULL)
return NULL;
pOc->pClient = pClient;
pOc->pScreen = pScreen;
pOc->resource = FakeClientID(pClient->index);
pOc->pNext = cs->pOverlayClients;
cs->pOverlayClients = pOc;
/*
* Create a resource for this element so it can be deleted
* when the client goes away.
*/
if (!AddResource (pOc->resource, CompositeClientOverlayType, (pointer) pOc))
return NULL;
return pOc;
}
/*
* Create the overlay window and map it
*/
Bool
compCreateOverlayWindow (ScreenPtr pScreen)
{
CompScreenPtr cs = GetCompScreen(pScreen);
WindowPtr pRoot = WindowTable[pScreen->myNum];
WindowPtr pWin;
XID overrideRedirect = TRUE;
int result;
pWin = cs->pOverlayWin =
CreateWindow (cs->overlayWid, pRoot,
0, 0, pScreen->width, pScreen->height, 0,
InputOutput, CWOverrideRedirect, &overrideRedirect,
pRoot->drawable.depth,
serverClient, pScreen->rootVisual, &result);
if (pWin == NULL)
return FALSE;
if (!AddResource(pWin->drawable.id, RT_WINDOW, (pointer)pWin))
return FALSE;
MapWindow(pWin, serverClient);
return TRUE;
}
/*
* Destroy the overlay window
*/
void
compDestroyOverlayWindow (ScreenPtr pScreen)
{
CompScreenPtr cs = GetCompScreen(pScreen);
cs->pOverlayWin = NullWindow;
FreeResource (cs->overlayWid, RT_NONE);
}