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 33 bool get(OptionBit Opt) const { return Val & (1U << static_cast<u32>(Opt)); } 34 35 FillContentsMode getFillContentsMode() const { 36 return static_cast<FillContentsMode>( 37 (Val >> static_cast<u32>(OptionBit::FillContents0of2)) & 3); 38 } 39 }; 40 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 49 Options load() const { return Options{atomic_load_relaxed(&Val)}; } 50 51 void clear(OptionBit Opt) { 52 atomic_fetch_and(&Val, ~(1U << static_cast<u32>(Opt)), 53 memory_order_relaxed); 54 } 55 56 void set(OptionBit Opt) { 57 atomic_fetch_or(&Val, 1U << static_cast<u32>(Opt), memory_order_relaxed); 58 } 59 60 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