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
16 namespace scudo {
17
18 enum class OptionBit {
19 MayReturnNull,
20 FillContents0of2,
21 FillContents1of2,
22 DeallocTypeMismatch,
23 DeleteSizeMismatch,
24 TrackAllocationStacks,
25 UseOddEvenTags,
26 UseMemoryTagging,
27 AddLargeAllocationSlack,
28 };
29
30 struct Options {
31 u32 Val;
32
getOptions33 bool get(OptionBit Opt) const { return Val & (1U << static_cast<u32>(Opt)); }
34
getFillContentsModeOptions35 FillContentsMode getFillContentsMode() const {
36 return static_cast<FillContentsMode>(
37 (Val >> static_cast<u32>(OptionBit::FillContents0of2)) & 3);
38 }
39 };
40
useMemoryTagging(const Options & Options)41 template <typename Config> bool useMemoryTagging(const Options &Options) {
42 return allocatorSupportsMemoryTagging<Config>() &&
43 Options.get(OptionBit::UseMemoryTagging);
44 }
45
46 struct AtomicOptions {
47 atomic_u32 Val = {};
48
loadAtomicOptions49 Options load() const { return Options{atomic_load_relaxed(&Val)}; }
50
clearAtomicOptions51 void clear(OptionBit Opt) {
52 atomic_fetch_and(&Val, ~(1U << static_cast<u32>(Opt)),
53 memory_order_relaxed);
54 }
55
setAtomicOptions56 void set(OptionBit Opt) {
57 atomic_fetch_or(&Val, 1U << static_cast<u32>(Opt), memory_order_relaxed);
58 }
59
setFillContentsModeAtomicOptions60 void setFillContentsMode(FillContentsMode FillContents) {
61 u32 Opts = atomic_load_relaxed(&Val), NewOpts;
62 do {
63 NewOpts = Opts;
64 NewOpts &= ~(3U << static_cast<u32>(OptionBit::FillContents0of2));
65 NewOpts |= static_cast<u32>(FillContents)
66 << static_cast<u32>(OptionBit::FillContents0of2);
67 } while (!atomic_compare_exchange_strong(&Val, &Opts, NewOpts,
68 memory_order_relaxed));
69 }
70 };
71
72 } // namespace scudo
73
74 #endif // SCUDO_OPTIONS_H_
75