static bool verifyShadowScheme() {
// Sanity checks for our shadow mapping scheme.
uptr AppStart, AppEnd;
if (Verbosity() >= 3) {
for (int i = 0; getAppRegion(i, &AppStart, &AppEnd); ++i) {
VPrintf(3, "App #%d: [%zx-%zx) (%zuGB)\n", i, AppStart, AppEnd,
(AppEnd - AppStart) >> 30);
}
}
for (int Scale = 0; Scale < 8; ++Scale) {
Mapping.initialize(Scale);
if (Verbosity() >= 3) {
VPrintf(3, "\nChecking scale %d\n", Scale);
uptr ShadowStart, ShadowEnd;
for (int i = 0; getShadowRegion(i, &ShadowStart, &ShadowEnd); ++i) {
VPrintf(3, "Shadow #%d: [%zx-%zx) (%zuGB)\n", i, ShadowStart,
ShadowEnd, (ShadowEnd - ShadowStart) >> 30);
}
for (int i = 0; getShadowRegion(i, &ShadowStart, &ShadowEnd); ++i) {
VPrintf(3, "Shadow(Shadow) #%d: [%zx-%zx)\n", i,
appToShadow(ShadowStart), appToShadow(ShadowEnd - 1)+1);
}
}
for (int i = 0; getAppRegion(i, &AppStart, &AppEnd); ++i) {
DCHECK(isAppMem(AppStart));
DCHECK(!isAppMem(AppStart - 1));
DCHECK(isAppMem(AppEnd - 1));
DCHECK(!isAppMem(AppEnd));
DCHECK(!isShadowMem(AppStart));
DCHECK(!isShadowMem(AppEnd - 1));
DCHECK(isShadowMem(appToShadow(AppStart)));
DCHECK(isShadowMem(appToShadow(AppEnd - 1)));
// Double-shadow checks.
DCHECK(!isShadowMem(appToShadow(appToShadow(AppStart))));
DCHECK(!isShadowMem(appToShadow(appToShadow(AppEnd - 1))));
}
// Ensure no shadow regions overlap each other.
uptr ShadowAStart, ShadowBStart, ShadowAEnd, ShadowBEnd;
for (int i = 0; getShadowRegion(i, &ShadowAStart, &ShadowAEnd); ++i) {
for (int j = 0; getShadowRegion(j, &ShadowBStart, &ShadowBEnd); ++j) {
DCHECK(i == j || ShadowAStart >= ShadowBEnd ||
ShadowAEnd <= ShadowBStart);
}
}
}
// Scan shadow memory to calculate the number of cache lines being accessed,
// i.e., the number of non-zero bits indexed by BitIdx in each shadow byte.
// We also clear the lowest bits (most recent working set snapshot).
static u32 computeWorkingSizeAndReset(u32 BitIdx) {
u32 WorkingSetSize = 0;
MemoryMappingLayout MemIter(true/*cache*/);
uptr Start, End, Prot;
while (MemIter.Next(&Start, &End, nullptr/*offs*/, nullptr/*file*/,
0/*file size*/, &Prot)) {
VPrintf(4, "%s: considering %p-%p app=%d shadow=%d prot=%u\n",
__FUNCTION__, Start, End, Prot, isAppMem(Start),
isShadowMem(Start));
if (isShadowMem(Start) && (Prot & MemoryMappingLayout::kProtectionWrite)) {
VPrintf(3, "%s: walking %p-%p\n", __FUNCTION__, Start, End);
WorkingSetSize += countAndClearShadowValues(BitIdx, Start, End);
}
}
return WorkingSetSize;
}