[scudo] Group MappedUser/AllocatedUser into PagesInfo (NFC)

[Chia-hungDuan]

Summary

Create a new PagesInfo to contain all the information about pages. This
is the preparation of adding new lock for page operations.

Note that primary32 hasn't switched to MemMap. Will add PagesInfo later
when we move to MemMap in primary32.

[Chia-hungDuan]

Rebase only

[Chia-hungDuan]

rebase only

[Chia-hungDuan]

Rebase only

[cferris]

LGTM

compiler-rt/lib/scudo/standalone/primary64.h

for (uptr I = 0; I < NumClasses; I++) {
         continue;
       RegionInfo *Region = getRegionInfo(I);
       // TODO: The call of `iterateOverBlocks` requires disabling
       // SizeClassAllocator64. We may consider locking each region on demand
       // only.
       Region->Mutex.assertHeld();
       const uptr BlockSize = getSizeByClassId(I);
       const uptr From = Region->RegionBeg;
-      const uptr To = From + Region->AllocatedUser;
+      const uptr To = From + Region->MemMapInfo.AllocatedUser;
       for (uptr Block = From; Block < To; Block += BlockSize)
         Callback(Block);
     }
   }
 
   void getStats(ScopedString *Str) {
     // TODO(kostyak): get the RSS per region.
     uptr TotalMapped = 0;
     uptr PoppedBlocks = 0;
     uptr PushedBlocks = 0;
     for (uptr I = 0; I < NumClasses; I++) {
       RegionInfo *Region = getRegionInfo(I);
       ScopedLock L(Region->Mutex);
-      if (Region->MappedUser)
-        TotalMapped += Region->MappedUser;
+      if (Region->MemMapInfo.MappedUser)
+        TotalMapped += Region->MemMapInfo.MappedUser;
       PoppedBlocks += Region->FreeListInfo.PoppedBlocks;
       PushedBlocks += Region->FreeListInfo.PushedBlocks;
     }
     Str->append("Stats: SizeClassAllocator64: %zuM mapped (%uM rss) in %zu "
                 "allocations; remains %zu\n",
                 TotalMapped >> 20, 0U, PoppedBlocks,
                 PoppedBlocks - PushedBlocks);
 
for (uptr I = 0; I != NumClasses; ++I) {
         continue;
       uptr Begin = RegionInfoArray[I].RegionBeg;
       // TODO(chiahungduan): In fact, We need to lock the RegionInfo::Mutex.
       // However, the RegionInfoData is passed with const qualifier and lock the
       // mutex requires modifying RegionInfoData, which means we need to remove
       // the const qualifier. This may lead to another undefined behavior (The
       // first one is accessing `AllocatedUser` without locking. It's better to
       // pass `RegionInfoData` as `void *` then we can lock the mutex properly.
-      uptr End = Begin + RegionInfoArray[I].AllocatedUser;
+      uptr End = Begin + RegionInfoArray[I].MemMapInfo.AllocatedUser;
       if (Begin > End || End - Begin < SizeClassMap::getSizeByClassId(I))
         continue;
       uptr RegionDistance;
       if (Begin <= Ptr) {
         if (Ptr < End)
           RegionDistance = 0;
         else
           RegionDistance = Ptr - End;
       } else {
         RegionDistance = Begin - Ptr;
       }
 
       if (RegionDistance < MinDistance) {
         MinDistance = RegionDistance;
         ClassId = I;
       }
     }
 
     BlockInfo B = {};
     if (MinDistance <= 8192) {
       B.RegionBegin = RegionInfoArray[ClassId].RegionBeg;
-      B.RegionEnd = B.RegionBegin + RegionInfoArray[ClassId].AllocatedUser;
+      B.RegionEnd =
+          B.RegionBegin + RegionInfoArray[ClassId].MemMapInfo.AllocatedUser;
       B.BlockSize = SizeClassMap::getSizeByClassId(ClassId);
       B.BlockBegin =
           B.RegionBegin + uptr(sptr(Ptr - B.RegionBegin) / sptr(B.BlockSize) *
                                sptr(B.BlockSize));
       while (B.BlockBegin < B.RegionBegin)
         B.BlockBegin += B.BlockSize;
       while (B.RegionEnd < B.BlockBegin + B.BlockSize)
         B.BlockBegin -= B.BlockSize;
private:
   };
 
   struct BlocksInfo {
     SinglyLinkedList<BatchGroup> BlockList = {};
     uptr PoppedBlocks = 0;
     uptr PushedBlocks = 0;
   };
 
+  struct PagesInfo {
+    MemMapT MemMap = {};
+    // Bytes mapped for user memory.
+    uptr MappedUser = 0;
+    // Bytes allocated for user memory.
+    uptr AllocatedUser = 0;
+  };
+
   struct UnpaddedRegionInfo {
     HybridMutex Mutex;
-    BlocksInfo FreeListInfo GUARDED_BY(Mutex);
     // This is initialized before thread creation.
     uptr RegionBeg = 0;
     u32 RandState GUARDED_BY(Mutex) = 0;
-    // Bytes mapped for user memory.
-    uptr MappedUser GUARDED_BY(Mutex) = 0;
-    // Bytes allocated for user memory.
-    uptr AllocatedUser GUARDED_BY(Mutex) = 0;
+    BlocksInfo FreeListInfo GUARDED_BY(Mutex);
+    PagesInfo MemMapInfo GUARDED_BY(Mutex);
     // The minimum size of pushed blocks to trigger page release.
     uptr TryReleaseThreshold GUARDED_BY(Mutex) = 0;
-    MemMapT MemMap = {};
     ReleaseToOsInfo ReleaseInfo GUARDED_BY(Mutex) = {};
     bool Exhausted GUARDED_BY(Mutex) = false;
   };
   struct RegionInfo : UnpaddedRegionInfo {
     char Padding[SCUDO_CACHE_LINE_SIZE -
                  (sizeof(UnpaddedRegionInfo) % SCUDO_CACHE_LINE_SIZE)] = {};
   };
   static_assert(sizeof(RegionInfo) % SCUDO_CACHE_LINE_SIZE == 0, "");
private:
   }
 
   NOINLINE bool populateFreeList(CacheT *C, uptr ClassId, RegionInfo *Region)
       REQUIRES(Region->Mutex) {
     const uptr Size = getSizeByClassId(ClassId);
     const u16 MaxCount = TransferBatch::getMaxCached(Size);
 
     const uptr RegionBeg = Region->RegionBeg;
-    const uptr MappedUser = Region->MappedUser;
-    const uptr TotalUserBytes = Region->AllocatedUser + MaxCount * Size;
+    const uptr MappedUser = Region->MemMapInfo.MappedUser;
+    const uptr TotalUserBytes =
+        Region->MemMapInfo.AllocatedUser + MaxCount * Size;
     // Map more space for blocks, if necessary.
     if (TotalUserBytes > MappedUser) {
       // Do the mmap for the user memory.
       const uptr MapSize =
           roundUp(TotalUserBytes - MappedUser, MapSizeIncrement);
       const uptr RegionBase = RegionBeg - getRegionBaseByClassId(ClassId);
       if (UNLIKELY(RegionBase + MappedUser + MapSize > RegionSize)) {
         Region->Exhausted = true;
         return false;
       }
-      // TODO: Consider allocating MemMap in init().
-      if (!Region->MemMap.isAllocated()) {
+      // TODO: Consider allocating MemMapInfo.MemMap in init().
+      if (!Region->MemMapInfo.MemMap.isAllocated()) {
         // TODO: Ideally, a region should reserve RegionSize because the memory
         // between `RegionBeg` and region base is still belong to a region and
         // it's just not used. In order to make it work on every platform (some
         // of them don't support `remap()` across the unused range), dispatch
         // from `RegionBeg` for now.
         const uptr ReserveSize =
             RegionSize - (RegionBeg - getRegionBaseByClassId(ClassId));
-        Region->MemMap = ReservedMemory.dispatch(RegionBeg, ReserveSize);
+        Region->MemMapInfo.MemMap =
+            ReservedMemory.dispatch(RegionBeg, ReserveSize);
       }
-      DCHECK(Region->MemMap.isAllocated());
+      DCHECK(Region->MemMapInfo.MemMap.isAllocated());
 
-      if (UNLIKELY(!Region->MemMap.remap(
+      if (UNLIKELY(!Region->MemMapInfo.MemMap.remap(
               RegionBeg + MappedUser, MapSize, "scudo:primary",
               MAP_ALLOWNOMEM | MAP_RESIZABLE |
                   (useMemoryTagging<Config>(Options.load()) ? MAP_MEMTAG
                                                             : 0)))) {
         return false;
       }
-      Region->MappedUser += MapSize;
+      Region->MemMapInfo.MappedUser += MapSize;
       C->getStats().add(StatMapped, MapSize);
     }
 
-    const u32 NumberOfBlocks = Min(
-        MaxNumBatches * MaxCount,
-        static_cast<u32>((Region->MappedUser - Region->AllocatedUser) / Size));
+    const u32 NumberOfBlocks =
+        Min(MaxNumBatches * MaxCount,
+            static_cast<u32>((Region->MemMapInfo.MappedUser -
+                              Region->MemMapInfo.AllocatedUser) /
+                             Size));
     DCHECK_GT(NumberOfBlocks, 0);
 
     constexpr u32 ShuffleArraySize =
         MaxNumBatches * TransferBatch::MaxNumCached;
     CompactPtrT ShuffleArray[ShuffleArraySize];
     DCHECK_LE(NumberOfBlocks, ShuffleArraySize);
 
     const uptr CompactPtrBase = getCompactPtrBaseByClassId(ClassId);
-    uptr P = RegionBeg + Region->AllocatedUser;
+    uptr P = RegionBeg + Region->MemMapInfo.AllocatedUser;
     for (u32 I = 0; I < NumberOfBlocks; I++, P += Size)
       ShuffleArray[I] = compactPtrInternal(CompactPtrBase, P);
 
     if (ClassId != SizeClassMap::BatchClassId) {
       u32 N = 1;
       uptr CurGroup = compactPtrGroup(ShuffleArray[0]);
       for (u32 I = 1; I < NumberOfBlocks; I++) {
         if (UNLIKELY(compactPtrGroup(ShuffleArray[I]) != CurGroup)) {
if (ClassId != SizeClassMap::BatchClassId) {
                      /*SameGroup=*/true);
     } else {
       pushBlocksImpl(C, ClassId, Region, ShuffleArray, NumberOfBlocks,
                      /*SameGroup=*/true);
     }
 
     const uptr AllocatedUser = Size * NumberOfBlocks;
     C->getStats().add(StatFree, AllocatedUser);
-    Region->AllocatedUser += AllocatedUser;
+    Region->MemMapInfo.AllocatedUser += AllocatedUser;
 
     return true;
   }
 
   void getStats(ScopedString *Str, uptr ClassId, RegionInfo *Region, uptr Rss)
       REQUIRES(Region->Mutex) {
-    if (Region->MappedUser == 0)
+    if (Region->MemMapInfo.MappedUser == 0)
       return;
     const uptr InUse =
         Region->FreeListInfo.PoppedBlocks - Region->FreeListInfo.PushedBlocks;
-    const uptr TotalChunks = Region->AllocatedUser / getSizeByClassId(ClassId);
+    const uptr TotalChunks =
+        Region->MemMapInfo.AllocatedUser / getSizeByClassId(ClassId);
     Str->append("%s %02zu (%6zu): mapped: %6zuK popped: %7zu pushed: %7zu "
                 "inuse: %6zu total: %6zu rss: %6zuK releases: %6zu last "
                 "released: %6zuK region: 0x%zx (0x%zx)\n",
                 Region->Exhausted ? "F" : " ", ClassId,
-                getSizeByClassId(ClassId), Region->MappedUser >> 10,
+                getSizeByClassId(ClassId), Region->MemMapInfo.MappedUser >> 10,
                 Region->FreeListInfo.PoppedBlocks,
                 Region->FreeListInfo.PushedBlocks, InUse, TotalChunks,
                 Rss >> 10, Region->ReleaseInfo.RangesReleased,
                 Region->ReleaseInfo.LastReleasedBytes >> 10, Region->RegionBeg,
                 getRegionBaseByClassId(ClassId));
   }
 
   NOINLINE uptr releaseToOSMaybe(RegionInfo *Region, uptr ClassId,
                                  ReleaseToOS ReleaseType = ReleaseToOS::Normal)
       REQUIRES(Region->Mutex) {
     const uptr BlockSize = getSizeByClassId(ClassId);
     const uptr PageSize = getPageSizeCached();
 
     DCHECK_GE(Region->FreeListInfo.PoppedBlocks,
               Region->FreeListInfo.PushedBlocks);
     const uptr BytesInFreeList =
-        Region->AllocatedUser - (Region->FreeListInfo.PoppedBlocks -
+        Region->MemMapInfo.AllocatedUser - (Region->FreeListInfo.PoppedBlocks -
                                             Region->FreeListInfo.PushedBlocks) *
                                                BlockSize;
 
     bool MaySkip = false;
 
     // Always update `BytesInFreeListAtLastCheckpoint` with the smallest value
     // so that we won't underestimate the releasable pages. For example, the
     // following is the region usage,
     //
     //  BytesInFreeListAtLastCheckpoint   AllocatedUser
if (ReleaseType == ReleaseToOS::Normal) {
       if (Region->ReleaseInfo.LastReleaseAtNs +
               static_cast<u64>(IntervalMs) * 1000000 >
           getMonotonicTimeFast()) {
         return 0; // Memory was returned recently.
       }
     }
 
     const uptr GroupSize = (1U << GroupSizeLog);
-    const uptr AllocatedUserEnd = Region->AllocatedUser + Region->RegionBeg;
+    const uptr AllocatedUserEnd =
+        Region->MemMapInfo.AllocatedUser + Region->RegionBeg;
     const uptr CompactPtrBase = getCompactPtrBaseByClassId(ClassId);
     auto DecompactPtr = [CompactPtrBase](CompactPtrT CompactPtr) {
       return decompactPtrInternal(CompactPtrBase, CompactPtr);
     };
 
     // Instead of always preparing PageMap for the entire region, we only do it
     // for the range of releasing groups. To do that, the free-block marking
     // process includes visiting BlockGroups twice.
NOINLINE uptr releaseToOSMaybe(RegionInfo *Region, uptr ClassId,
     // The last block may straddle the group boundary. Rounding up to BlockSize
     // to get the exact range.
     const uptr ReleaseEnd =
         roundUpSlow(LastGroupEnd - Region->RegionBeg, BlockSize) +
         Region->RegionBeg;
     const uptr ReleaseRangeSize = ReleaseEnd - ReleaseBase;
     const uptr ReleaseOffset = ReleaseBase - Region->RegionBeg;
 
-    RegionReleaseRecorder<MemMapT> Recorder(&Region->MemMap, Region->RegionBeg,
-                                            ReleaseOffset);
+    RegionReleaseRecorder<MemMapT> Recorder(&Region->MemMapInfo.MemMap,
+                                            Region->RegionBeg, ReleaseOffset);
     PageReleaseContext Context(BlockSize, /*NumberOfRegions=*/1U,
                                ReleaseRangeSize, ReleaseOffset);
 
     for (BatchGroup &BG : GroupToRelease) {
       const uptr BatchGroupBase =
           decompactGroupBase(CompactPtrBase, BG.CompactPtrGroupBase);
       const uptr BatchGroupEnd = BatchGroupBase + GroupSize;
       const uptr AllocatedGroupSize = AllocatedUserEnd >= BatchGroupEnd
for (BatchGroup &BG : GroupToRelease) {
 
       if (NumBlocks == MaxContainedBlocks) {
         for (const auto &It : BG.Batches)
           for (u16 I = 0; I < It.getCount(); ++I)
             DCHECK_EQ(compactPtrGroup(It.get(I)), BG.CompactPtrGroupBase);
 
         Context.markRangeAsAllCounted(BatchGroupBase, BatchGroupUsedEnd,
                                       Region->RegionBeg, /*RegionIndex=*/0,
-                                      Region->AllocatedUser);
+                                      Region->MemMapInfo.AllocatedUser);
       } else {
         DCHECK_LT(NumBlocks, MaxContainedBlocks);
         // Note that we don't always visit blocks in each BatchGroup so that we
         // may miss the chance of releasing certain pages that cross
         // BatchGroups.
         Context.markFreeBlocksInRegion(
             BG.Batches, DecompactPtr, Region->RegionBeg, /*RegionIndex=*/0,
-            Region->AllocatedUser, MayContainLastBlockInRegion);
+            Region->MemMapInfo.AllocatedUser, MayContainLastBlockInRegion);
       }
     }
 
     DCHECK(Context.hasBlockMarked());
 
     auto SkipRegion = [](UNUSED uptr RegionIndex) { return false; };
     releaseFreeMemoryToOS(Context, Recorder, SkipRegion);