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.
SetErrnoOnNull(void * ptr)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.
CheckAlignedAllocAlignmentAndSize(uptr alignment,uptr size)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 *).
CheckPosixMemalignAlignment(uptr alignment)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.
CheckForCallocOverflow(uptr size,uptr n)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.
CheckForPvallocOverflow(uptr size,uptr 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
77