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
21namespace __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.
27void SetErrnoToENOMEM();
28
29// A common errno setting logic shared by almost all sanitizer allocator APIs.
30inline 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.
44inline bool CheckAlignedAllocAlignmentAndSize(uptr alignment, uptr size) {
45#if SANITIZER_POSIX
46 return alignment != 0 && IsPowerOfTwo(x: 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 *).
55inline bool CheckPosixMemalignAlignment(uptr alignment) {
56 return alignment != 0 && IsPowerOfTwo(x: alignment) &&
57 (alignment % sizeof(void *)) == 0;
58}
59
60// Returns true if calloc(size, n) call overflows on size*n calculation.
61inline 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.
70inline bool CheckForPvallocOverflow(uptr size, uptr page_size) {
71 return RoundUpTo(size, boundary: page_size) < size;
72}
73
74} // namespace __sanitizer
75
76#endif // SANITIZER_ALLOCATOR_CHECKS_H
77