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Diffstat (limited to 'contrib/llvm-project/compiler-rt/lib/scudo/standalone/common.h')
-rw-r--r-- | contrib/llvm-project/compiler-rt/lib/scudo/standalone/common.h | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/contrib/llvm-project/compiler-rt/lib/scudo/standalone/common.h b/contrib/llvm-project/compiler-rt/lib/scudo/standalone/common.h new file mode 100644 index 000000000000..9037f92b4976 --- /dev/null +++ b/contrib/llvm-project/compiler-rt/lib/scudo/standalone/common.h @@ -0,0 +1,196 @@ +//===-- common.h ------------------------------------------------*- C++ -*-===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#ifndef SCUDO_COMMON_H_ +#define SCUDO_COMMON_H_ + +#include "internal_defs.h" + +#include "fuchsia.h" +#include "linux.h" + +#include <stddef.h> +#include <string.h> + +namespace scudo { + +template <class Dest, class Source> inline Dest bit_cast(const Source &S) { + static_assert(sizeof(Dest) == sizeof(Source), ""); + Dest D; + memcpy(&D, &S, sizeof(D)); + return D; +} + +inline constexpr uptr roundUpTo(uptr X, uptr Boundary) { + return (X + Boundary - 1) & ~(Boundary - 1); +} + +inline constexpr uptr roundDownTo(uptr X, uptr Boundary) { + return X & ~(Boundary - 1); +} + +inline constexpr bool isAligned(uptr X, uptr Alignment) { + return (X & (Alignment - 1)) == 0; +} + +template <class T> constexpr T Min(T A, T B) { return A < B ? A : B; } + +template <class T> constexpr T Max(T A, T B) { return A > B ? A : B; } + +template <class T> void Swap(T &A, T &B) { + T Tmp = A; + A = B; + B = Tmp; +} + +inline bool isPowerOfTwo(uptr X) { return (X & (X - 1)) == 0; } + +inline uptr getMostSignificantSetBitIndex(uptr X) { + DCHECK_NE(X, 0U); + return SCUDO_WORDSIZE - 1U - static_cast<uptr>(__builtin_clzl(X)); +} + +inline uptr roundUpToPowerOfTwo(uptr Size) { + DCHECK(Size); + if (isPowerOfTwo(Size)) + return Size; + const uptr Up = getMostSignificantSetBitIndex(Size); + DCHECK_LT(Size, (1UL << (Up + 1))); + DCHECK_GT(Size, (1UL << Up)); + return 1UL << (Up + 1); +} + +inline uptr getLeastSignificantSetBitIndex(uptr X) { + DCHECK_NE(X, 0U); + return static_cast<uptr>(__builtin_ctzl(X)); +} + +inline uptr getLog2(uptr X) { + DCHECK(isPowerOfTwo(X)); + return getLeastSignificantSetBitIndex(X); +} + +inline u32 getRandomU32(u32 *State) { + // ANSI C linear congruential PRNG (16-bit output). + // return (*State = *State * 1103515245 + 12345) >> 16; + // XorShift (32-bit output). + *State ^= *State << 13; + *State ^= *State >> 17; + *State ^= *State << 5; + return *State; +} + +inline u32 getRandomModN(u32 *State, u32 N) { + return getRandomU32(State) % N; // [0, N) +} + +template <typename T> inline void shuffle(T *A, u32 N, u32 *RandState) { + if (N <= 1) + return; + u32 State = *RandState; + for (u32 I = N - 1; I > 0; I--) + Swap(A[I], A[getRandomModN(&State, I + 1)]); + *RandState = State; +} + +// Hardware specific inlinable functions. + +inline void yieldProcessor(u8 Count) { +#if defined(__i386__) || defined(__x86_64__) + __asm__ __volatile__("" ::: "memory"); + for (u8 I = 0; I < Count; I++) + __asm__ __volatile__("pause"); +#elif defined(__aarch64__) || defined(__arm__) + __asm__ __volatile__("" ::: "memory"); + for (u8 I = 0; I < Count; I++) + __asm__ __volatile__("yield"); +#endif + __asm__ __volatile__("" ::: "memory"); +} + +// Platform specific functions. + +extern uptr PageSizeCached; +uptr getPageSizeSlow(); +inline uptr getPageSizeCached() { + // Bionic uses a hardcoded value. + if (SCUDO_ANDROID) + return 4096U; + if (LIKELY(PageSizeCached)) + return PageSizeCached; + return getPageSizeSlow(); +} + +// Returns 0 if the number of CPUs could not be determined. +u32 getNumberOfCPUs(); + +const char *getEnv(const char *Name); + +u64 getMonotonicTime(); + +u32 getThreadID(); + +// Our randomness gathering function is limited to 256 bytes to ensure we get +// as many bytes as requested, and avoid interruptions (on Linux). +constexpr uptr MaxRandomLength = 256U; +bool getRandom(void *Buffer, uptr Length, bool Blocking = false); + +// Platform memory mapping functions. + +#define MAP_ALLOWNOMEM (1U << 0) +#define MAP_NOACCESS (1U << 1) +#define MAP_RESIZABLE (1U << 2) +#define MAP_MEMTAG (1U << 3) + +// Our platform memory mapping use is restricted to 3 scenarios: +// - reserve memory at a random address (MAP_NOACCESS); +// - commit memory in a previously reserved space; +// - commit memory at a random address. +// As such, only a subset of parameters combinations is valid, which is checked +// by the function implementation. The Data parameter allows to pass opaque +// platform specific data to the function. +// Returns nullptr on error or dies if MAP_ALLOWNOMEM is not specified. +void *map(void *Addr, uptr Size, const char *Name, uptr Flags = 0, + MapPlatformData *Data = nullptr); + +// Indicates that we are getting rid of the whole mapping, which might have +// further consequences on Data, depending on the platform. +#define UNMAP_ALL (1U << 0) + +void unmap(void *Addr, uptr Size, uptr Flags = 0, + MapPlatformData *Data = nullptr); + +void releasePagesToOS(uptr BaseAddress, uptr Offset, uptr Size, + MapPlatformData *Data = nullptr); + +// Internal map & unmap fatal error. This must not call map(). +void NORETURN dieOnMapUnmapError(bool OutOfMemory = false); + +// Logging related functions. + +void setAbortMessage(const char *Message); + +struct BlockInfo { + uptr BlockBegin; + uptr BlockSize; + uptr RegionBegin; + uptr RegionEnd; +}; + +constexpr unsigned char PatternFillByte = 0xAB; + +enum FillContentsMode { + NoFill = 0, + ZeroFill = 1, + PatternOrZeroFill = 2 // Pattern fill unless the memory is known to be + // zero-initialized already. +}; + +} // namespace scudo + +#endif // SCUDO_COMMON_H_ |