src/libcompiler_builtins/compiler-rt/lib/scudo/scudo_allocator.h

   1 //===-- scudo_allocator.h ---------------------------------------*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 ///
  10 /// Header for scudo_allocator.cpp.
  11 ///
  12 //===----------------------------------------------------------------------===//
  13
  14 #ifndef SCUDO_ALLOCATOR_H_
  15 #define SCUDO_ALLOCATOR_H_
  16
  17 #include "scudo_flags.h"
  18
  19 #include "sanitizer_common/sanitizer_allocator.h"
  20
  21 #include <atomic>
  22
  23 namespace __scudo {
  24
  25 enum AllocType : u8 {
  26   FromMalloc    = 0, // Memory block came from malloc, realloc, calloc, etc.
  27   FromNew       = 1, // Memory block came from operator new.
  28   FromNewArray  = 2, // Memory block came from operator new [].
  29   FromMemalign  = 3, // Memory block came from memalign, posix_memalign, etc.
  30 };
  31
  32 enum ChunkState : u8 {
  33   ChunkAvailable  = 0,
  34   ChunkAllocated  = 1,
  35   ChunkQuarantine = 2
  36 };
  37
  38 // Our header requires 64 bits of storage. Having the offset saves us from
  39 // using functions such as GetBlockBegin, that is fairly costly. Our first
  40 // implementation used the MetaData as well, which offers the advantage of
  41 // being stored away from the chunk itself, but accessing it was costly as
  42 // well. The header will be atomically loaded and stored using the 16-byte
  43 // primitives offered by the platform (likely requires cmpxchg16b support).
  44 typedef u64 PackedHeader;
  45 struct UnpackedHeader {
  46   u64 Checksum    : 16;
  47   u64 UnusedBytes : 20; // Needed for reallocation purposes.
  48   u64 State       : 2;  // available, allocated, or quarantined
  49   u64 AllocType   : 2;  // malloc, new, new[], or memalign
  50   u64 Offset      : 16; // Offset from the beginning of the backend
  51                         // allocation to the beginning of the chunk itself,
  52                         // in multiples of MinAlignment. See comment about
  53                         // its maximum value and test in init().
  54   u64 Salt        : 8;
  55 };
  56
  57 typedef std::atomic<PackedHeader> AtomicPackedHeader;
  58 COMPILER_CHECK(sizeof(UnpackedHeader) == sizeof(PackedHeader));
  59
  60 // Minimum alignment of 8 bytes for 32-bit, 16 for 64-bit
  61 const uptr MinAlignmentLog = FIRST_32_SECOND_64(3, 4);
  62 const uptr MaxAlignmentLog = 24; // 16 MB
  63 const uptr MinAlignment = 1 << MinAlignmentLog;
  64 const uptr MaxAlignment = 1 << MaxAlignmentLog;
  65
  66 const uptr ChunkHeaderSize = sizeof(PackedHeader);
  67 const uptr AlignedChunkHeaderSize =
  68     (ChunkHeaderSize + MinAlignment - 1) & ~(MinAlignment - 1);
  69
  70 struct AllocatorOptions {
  71   u32 QuarantineSizeMb;
  72   u32 ThreadLocalQuarantineSizeKb;
  73   bool MayReturnNull;
  74   s32 ReleaseToOSIntervalMs;
  75   bool DeallocationTypeMismatch;
  76   bool DeleteSizeMismatch;
  77   bool ZeroContents;
  78
  79   void setFrom(const Flags *f, const CommonFlags *cf);
  80   void copyTo(Flags *f, CommonFlags *cf) const;
  81 };
  82
  83 void initAllocator(const AllocatorOptions &options);
  84 void drainQuarantine();
  85
  86 void *scudoMalloc(uptr Size, AllocType Type);
  87 void scudoFree(void *Ptr, AllocType Type);
  88 void scudoSizedFree(void *Ptr, uptr Size, AllocType Type);
  89 void *scudoRealloc(void *Ptr, uptr Size);
  90 void *scudoCalloc(uptr NMemB, uptr Size);
  91 void *scudoMemalign(uptr Alignment, uptr Size);
  92 void *scudoValloc(uptr Size);
  93 void *scudoPvalloc(uptr Size);
  94 int scudoPosixMemalign(void **MemPtr, uptr Alignment, uptr Size);
  95 void *scudoAlignedAlloc(uptr Alignment, uptr Size);
  96 uptr scudoMallocUsableSize(void *Ptr);
  97
  98 #include "scudo_allocator_secondary.h"
  99
 100 }  // namespace __scudo
 101
 102 #endif  // SCUDO_ALLOCATOR_H_