1//===-- options.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#ifndef SCUDO_OPTIONS_H_
10#define SCUDO_OPTIONS_H_
11
12#include "atomic_helpers.h"
13#include "common.h"
14#include "memtag.h"
15
16namespace scudo {
17
18enum class OptionBit {
19 MayReturnNull,
20 FillContents0of2,
21 FillContents1of2,
22 DeallocAlignMismatch,
23 DeallocTypeMismatch,
24 DeleteSizeMismatch,
25 TrackAllocationStacks,
26 UseOddEvenTags,
27 UseMemoryTagging,
28 AddLargeAllocationSlack,
29};
30
31struct Options {
32 u32 Val;
33
34 bool get(OptionBit Opt) const { return Val & (1U << static_cast<u32>(Opt)); }
35
36 FillContentsMode getFillContentsMode() const {
37 return static_cast<FillContentsMode>(
38 (Val >> static_cast<u32>(OptionBit::FillContents0of2)) & 3);
39 }
40};
41
42template <typename Config> bool useMemoryTagging(const Options &Options) {
43 return allocatorSupportsMemoryTagging<Config>() &&
44 Options.get(Opt: OptionBit::UseMemoryTagging);
45}
46
47struct AtomicOptions {
48 atomic_u32 Val = {};
49
50 Options load() const { return Options{.Val: atomic_load_relaxed(A: &Val)}; }
51
52 void clear(OptionBit Opt) {
53 atomic_fetch_and(A: &Val, V: ~(1U << static_cast<u32>(Opt)),
54 MO: memory_order_relaxed);
55 }
56
57 void set(OptionBit Opt) {
58 atomic_fetch_or(A: &Val, V: 1U << static_cast<u32>(Opt), MO: memory_order_relaxed);
59 }
60
61 void setFillContentsMode(FillContentsMode FillContents) {
62 u32 Opts = atomic_load_relaxed(A: &Val), NewOpts;
63 do {
64 NewOpts = Opts;
65 NewOpts &= ~(3U << static_cast<u32>(OptionBit::FillContents0of2));
66 NewOpts |= static_cast<u32>(FillContents)
67 << static_cast<u32>(OptionBit::FillContents0of2);
68 } while (!atomic_compare_exchange_strong(A: &Val, Cmp: &Opts, Xchg: NewOpts,
69 MO: memory_order_relaxed));
70 }
71};
72
73} // namespace scudo
74
75#endif // SCUDO_OPTIONS_H_
76