1 //===-- sanitizer_allocator_checks.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 // Various checks shared between ThreadSanitizer, MemorySanitizer, etc. memory
11 // allocators.
12 //
13 //===----------------------------------------------------------------------===//
14
15 #ifndef SANITIZER_ALLOCATOR_CHECKS_H
16 #define SANITIZER_ALLOCATOR_CHECKS_H
17
18 #include "sanitizer_internal_defs.h"
19 #include "sanitizer_common.h"
20 #include "sanitizer_platform.h"
21
22 namespace __sanitizer {
23
24 // The following is defined in a separate compilation unit to avoid pulling in
25 // sanitizer_errno.h in this header, which leads to conflicts when other system
26 // headers include errno.h. This is usually the result of an unlikely event,
27 // and as such we do not care as much about having it inlined.
28 void SetErrnoToENOMEM();
29
30 // A common errno setting logic shared by almost all sanitizer allocator APIs.
SetErrnoOnNull(void * ptr)31 INLINE void *SetErrnoOnNull(void *ptr) {
32 if (UNLIKELY(!ptr))
33 SetErrnoToENOMEM();
34 return ptr;
35 }
36
37 // In case of the check failure, the caller of the following Check... functions
38 // should "return POLICY::OnBadRequest();" where POLICY is the current allocator
39 // failure handling policy.
40
41 // Checks aligned_alloc() parameters, verifies that the alignment is a power of
42 // two and that the size is a multiple of alignment for POSIX implementation,
43 // and a bit relaxed requirement for non-POSIX ones, that the size is a multiple
44 // of alignment.
CheckAlignedAllocAlignmentAndSize(uptr alignment,uptr size)45 INLINE bool CheckAlignedAllocAlignmentAndSize(uptr alignment, uptr size) {
46 #if SANITIZER_POSIX
47 return alignment != 0 && IsPowerOfTwo(alignment) &&
48 (size & (alignment - 1)) == 0;
49 #else
50 return alignment != 0 && size % alignment == 0;
51 #endif
52 }
53
54 // Checks posix_memalign() parameters, verifies that alignment is a power of two
55 // and a multiple of sizeof(void *).
CheckPosixMemalignAlignment(uptr alignment)56 INLINE bool CheckPosixMemalignAlignment(uptr alignment) {
57 return alignment != 0 && IsPowerOfTwo(alignment) &&
58 (alignment % sizeof(void *)) == 0; // NOLINT
59 }
60
61 // Returns true if calloc(size, n) call overflows on size*n calculation.
CheckForCallocOverflow(uptr size,uptr n)62 INLINE bool CheckForCallocOverflow(uptr size, uptr n) {
63 if (!size)
64 return false;
65 uptr max = (uptr)-1L;
66 return (max / size) < n;
67 }
68
69 // Returns true if the size passed to pvalloc overflows when rounded to the next
70 // multiple of page_size.
CheckForPvallocOverflow(uptr size,uptr page_size)71 INLINE bool CheckForPvallocOverflow(uptr size, uptr page_size) {
72 return RoundUpTo(size, page_size) < size;
73 }
74
75 } // namespace __sanitizer
76
77 #endif // SANITIZER_ALLOCATOR_CHECKS_H
78