libsanitizer/sanitizer_common/sanitizer_allocator_checks.h

   1 //===-- sanitizer_allocator_checks.h ----------------------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // Various checks shared between ThreadSanitizer, MemorySanitizer, etc. memory
  10 // allocators.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #ifndef SANITIZER_ALLOCATOR_CHECKS_H
  15 #define SANITIZER_ALLOCATOR_CHECKS_H
  16
  17 #include "sanitizer_internal_defs.h"
  18 #include "sanitizer_common.h"
  19 #include "sanitizer_platform.h"
  20
  21 namespace __sanitizer {
  22
  23 // The following is defined in a separate compilation unit to avoid pulling in
  24 // sanitizer_errno.h in this header, which leads to conflicts when other system
  25 // headers include errno.h. This is usually the result of an unlikely event,
  26 // and as such we do not care as much about having it inlined.
  27 void SetErrnoToENOMEM();
  28
  29 // A common errno setting logic shared by almost all sanitizer allocator APIs.
  30 inline void *SetErrnoOnNull(void *ptr) {
  31   if (UNLIKELY(!ptr))
  32     SetErrnoToENOMEM();
  33   return ptr;
  34 }
  35
  36 // In case of the check failure, the caller of the following Check... functions
  37 // should "return POLICY::OnBadRequest();" where POLICY is the current allocator
  38 // failure handling policy.
  39
  40 // Checks aligned_alloc() parameters, verifies that the alignment is a power of
  41 // two and that the size is a multiple of alignment for POSIX implementation,
  42 // and a bit relaxed requirement for non-POSIX ones, that the size is a multiple
  43 // of alignment.
  44 inline bool CheckAlignedAllocAlignmentAndSize(uptr alignment, uptr size) {
  45 #if SANITIZER_POSIX
  46   return alignment != 0 && IsPowerOfTwo(alignment) &&
  47          (size & (alignment - 1)) == 0;
  48 #else
  49   return alignment != 0 && size % alignment == 0;
  50 #endif
  51 }
  52
  53 // Checks posix_memalign() parameters, verifies that alignment is a power of two
  54 // and a multiple of sizeof(void *).
  55 inline bool CheckPosixMemalignAlignment(uptr alignment) {
  56   return alignment != 0 && IsPowerOfTwo(alignment) &&
  57          (alignment % sizeof(void *)) == 0;
  58 }
  59
  60 // Returns true if calloc(size, n) call overflows on size*n calculation.
  61 inline bool CheckForCallocOverflow(uptr size, uptr n) {
  62   if (!size)
  63     return false;
  64   uptr max = (uptr)-1L;
  65   return (max / size) < n;
  66 }
  67
  68 // Returns true if the size passed to pvalloc overflows when rounded to the next
  69 // multiple of page_size.
  70 inline bool CheckForPvallocOverflow(uptr size, uptr page_size) {
  71   return RoundUpTo(size, page_size) < size;
  72 }
  73
  74 } // namespace __sanitizer
  75
  76 #endif  // SANITIZER_ALLOCATOR_CHECKS_H