Files
xserver/hw/xfree86/shadowfb/shadowfb.c
Enrico Weigelt, metux IT consult d8e6511b1b xfree86: use calloc() instead of malloc()
Using calloc() instead of malloc() as preventive measure, so there
never can be any hidden bugs or leaks due uninitialized memory.

The extra cost of using this compiler intrinsic should be practically
impossible to measure - in many cases a good compiler can even deduce
if certain areas really don't need to be zero'd (because they're written
to right after allocation) and create more efficient machine code.

The code pathes in question are pretty cold anyways, so it's probably
not worth even thinking about potential extra runtime costs.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
2025-06-12 16:49:57 +02:00

170 lines
4.5 KiB
C

/*
Copyright (C) 1999. The XFree86 Project Inc.
Copyright 2014 Red Hat, Inc.
Written by Mark Vojkovich (mvojkovi@ucsd.edu)
Pre-fb-write callbacks and RENDER support - Nolan Leake (nolan@vmware.com)
*/
#include <xorg-config.h>
#include <X11/X.h>
#include <X11/Xproto.h>
#include <X11/fonts/font.h>
#include <X11/fonts/fontstruct.h>
#include "dix/screen_hooks_priv.h"
#include "misc.h"
#include "pixmapstr.h"
#include "input.h"
#include "mi.h"
#include "scrnintstr.h"
#include "windowstr.h"
#include "gcstruct.h"
#include "dixfontstr.h"
#include "xf86.h"
#include "xf86str.h"
#include "shadowfb.h"
#include "picturestr.h"
static void ShadowCloseScreen(CallbackListPtr *, ScreenPtr pScreen, void *unused);
static Bool ShadowCreateRootWindow(WindowPtr pWin);
typedef struct {
ScrnInfoPtr pScrn;
RefreshAreaFuncPtr preRefresh;
RefreshAreaFuncPtr postRefresh;
CreateWindowProcPtr CreateWindow;
} ShadowScreenRec, *ShadowScreenPtr;
static DevPrivateKeyRec ShadowScreenKeyRec;
static ShadowScreenPtr
shadowfbGetScreenPrivate(ScreenPtr pScreen)
{
return dixLookupPrivate(&(pScreen)->devPrivates, &ShadowScreenKeyRec);
}
Bool
ShadowFBInit2(ScreenPtr pScreen,
RefreshAreaFuncPtr preRefreshArea,
RefreshAreaFuncPtr postRefreshArea)
{
ScrnInfoPtr pScrn = xf86ScreenToScrn(pScreen);
ShadowScreenPtr pPriv;
if (!preRefreshArea && !postRefreshArea)
return FALSE;
if (!dixRegisterPrivateKey(&ShadowScreenKeyRec, PRIVATE_SCREEN, 0))
return FALSE;
if (!(pPriv = (ShadowScreenPtr) calloc(1, sizeof(ShadowScreenRec))))
return FALSE;
dixSetPrivate(&pScreen->devPrivates, &ShadowScreenKeyRec, pPriv);
pPriv->pScrn = pScrn;
pPriv->preRefresh = preRefreshArea;
pPriv->postRefresh = postRefreshArea;
dixScreenHookClose(pScreen, ShadowCloseScreen);
pPriv->CreateWindow = pScreen->CreateWindow;
pScreen->CreateWindow = ShadowCreateRootWindow;
return TRUE;
}
Bool
ShadowFBInit(ScreenPtr pScreen, RefreshAreaFuncPtr refreshArea)
{
return ShadowFBInit2(pScreen, NULL, refreshArea);
}
/*
* Note that we don't do DamageEmpty, or indeed look at the region inside the
* DamagePtr at all. This is an optimization, believe it or not. The
* incoming RegionPtr is the new damage, and if we were to empty the region
* miext/damage would just have to waste time reallocating and re-unioning
* it every time, whereas if we leave it around the union gets fast-pathed
* away.
*/
static void
shadowfbReportPre(DamagePtr damage, RegionPtr reg, void *closure)
{
ShadowScreenPtr pPriv = closure;
if (!pPriv->pScrn->vtSema)
return;
pPriv->preRefresh(pPriv->pScrn, RegionNumRects(reg), RegionRects(reg));
}
static void
shadowfbReportPost(DamagePtr damage, RegionPtr reg, void *closure)
{
ShadowScreenPtr pPriv = closure;
if (!pPriv->pScrn->vtSema)
return;
pPriv->postRefresh(pPriv->pScrn, RegionNumRects(reg), RegionRects(reg));
}
static Bool
ShadowCreateRootWindow(WindowPtr pWin)
{
Bool ret;
ScreenPtr pScreen = pWin->drawable.pScreen;
ShadowScreenPtr pPriv = shadowfbGetScreenPrivate(pScreen);
/* paranoia */
if (pWin != pScreen->root)
ErrorF("ShadowCreateRootWindow called unexpectedly\n");
/* call down, but don't hook ourselves back in; we know the first time
* we're called it's for the root window.
*/
pScreen->CreateWindow = pPriv->CreateWindow;
ret = pScreen->CreateWindow(pWin);
/* this might look like it leaks, but the damage code reaps listeners
* when their drawable disappears.
*/
if (ret) {
DamagePtr damage;
if (pPriv->preRefresh) {
damage = DamageCreate(shadowfbReportPre, NULL,
DamageReportRawRegion,
TRUE, pScreen, pPriv);
DamageRegister(&pWin->drawable, damage);
}
if (pPriv->postRefresh) {
damage = DamageCreate(shadowfbReportPost, NULL,
DamageReportRawRegion,
TRUE, pScreen, pPriv);
DamageSetReportAfterOp(damage, TRUE);
DamageRegister(&pWin->drawable, damage);
}
}
return ret;
}
static void ShadowCloseScreen(CallbackListPtr *pcbl, ScreenPtr pScreen, void *unused)
{
dixScreenUnhookClose(pScreen, ShadowCloseScreen);
ShadowScreenPtr pPriv = shadowfbGetScreenPrivate(pScreen);
if (!pPriv)
return;
free(pPriv);
dixSetPrivate(&pScreen->devPrivates, &ShadowScreenKeyRec, NULL);
}