diff options
Diffstat (limited to 'third_party/abseil_cpp/absl/base/internal/direct_mmap.h')
| -rw-r--r-- | third_party/abseil_cpp/absl/base/internal/direct_mmap.h | 166 |
1 files changed, 0 insertions, 166 deletions
diff --git a/third_party/abseil_cpp/absl/base/internal/direct_mmap.h b/third_party/abseil_cpp/absl/base/internal/direct_mmap.h deleted file mode 100644 index 16accf0966..0000000000 --- a/third_party/abseil_cpp/absl/base/internal/direct_mmap.h +++ /dev/null @@ -1,166 +0,0 @@ -// Copyright 2017 The Abseil Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// https://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. -// -// Functions for directly invoking mmap() via syscall, avoiding the case where -// mmap() has been locally overridden. - -#ifndef ABSL_BASE_INTERNAL_DIRECT_MMAP_H_ -#define ABSL_BASE_INTERNAL_DIRECT_MMAP_H_ - -#include "absl/base/config.h" - -#if ABSL_HAVE_MMAP - -#include <sys/mman.h> - -#ifdef __linux__ - -#include <sys/types.h> -#ifdef __BIONIC__ -#include <sys/syscall.h> -#else -#include <syscall.h> -#endif - -#include <linux/unistd.h> -#include <unistd.h> -#include <cerrno> -#include <cstdarg> -#include <cstdint> - -#ifdef __mips__ -// Include definitions of the ABI currently in use. -#ifdef __BIONIC__ -// Android doesn't have sgidefs.h, but does have asm/sgidefs.h, which has the -// definitions we need. -#include <asm/sgidefs.h> -#else -#include <sgidefs.h> -#endif // __BIONIC__ -#endif // __mips__ - -// SYS_mmap and SYS_munmap are not defined in Android. -#ifdef __BIONIC__ -extern "C" void* __mmap2(void*, size_t, int, int, int, size_t); -#if defined(__NR_mmap) && !defined(SYS_mmap) -#define SYS_mmap __NR_mmap -#endif -#ifndef SYS_munmap -#define SYS_munmap __NR_munmap -#endif -#endif // __BIONIC__ - -#if defined(__NR_mmap2) && !defined(SYS_mmap2) -#define SYS_mmap2 __NR_mmap2 -#endif - -namespace absl { -ABSL_NAMESPACE_BEGIN -namespace base_internal { - -// Platform specific logic extracted from -// https://chromium.googlesource.com/linux-syscall-support/+/master/linux_syscall_support.h -inline void* DirectMmap(void* start, size_t length, int prot, int flags, int fd, - off64_t offset) noexcept { -#if defined(__i386__) || defined(__ARM_ARCH_3__) || defined(__ARM_EABI__) || \ - (defined(__mips__) && _MIPS_SIM == _MIPS_SIM_ABI32) || \ - (defined(__PPC__) && !defined(__PPC64__)) || \ - (defined(__riscv) && __riscv_xlen == 32) || \ - (defined(__s390__) && !defined(__s390x__)) - // On these architectures, implement mmap with mmap2. - static int pagesize = 0; - if (pagesize == 0) { -#if defined(__wasm__) || defined(__asmjs__) - pagesize = getpagesize(); -#else - pagesize = sysconf(_SC_PAGESIZE); -#endif - } - if (offset < 0 || offset % pagesize != 0) { - errno = EINVAL; - return MAP_FAILED; - } -#ifdef __BIONIC__ - // SYS_mmap2 has problems on Android API level <= 16. - // Workaround by invoking __mmap2() instead. - return __mmap2(start, length, prot, flags, fd, offset / pagesize); -#else - return reinterpret_cast<void*>( - syscall(SYS_mmap2, start, length, prot, flags, fd, - static_cast<off_t>(offset / pagesize))); -#endif -#elif defined(__s390x__) - // On s390x, mmap() arguments are passed in memory. - unsigned long buf[6] = {reinterpret_cast<unsigned long>(start), // NOLINT - static_cast<unsigned long>(length), // NOLINT - static_cast<unsigned long>(prot), // NOLINT - static_cast<unsigned long>(flags), // NOLINT - static_cast<unsigned long>(fd), // NOLINT - static_cast<unsigned long>(offset)}; // NOLINT - return reinterpret_cast<void*>(syscall(SYS_mmap, buf)); -#elif defined(__x86_64__) -// The x32 ABI has 32 bit longs, but the syscall interface is 64 bit. -// We need to explicitly cast to an unsigned 64 bit type to avoid implicit -// sign extension. We can't cast pointers directly because those are -// 32 bits, and gcc will dump ugly warnings about casting from a pointer -// to an integer of a different size. We also need to make sure __off64_t -// isn't truncated to 32-bits under x32. -#define MMAP_SYSCALL_ARG(x) ((uint64_t)(uintptr_t)(x)) - return reinterpret_cast<void*>( - syscall(SYS_mmap, MMAP_SYSCALL_ARG(start), MMAP_SYSCALL_ARG(length), - MMAP_SYSCALL_ARG(prot), MMAP_SYSCALL_ARG(flags), - MMAP_SYSCALL_ARG(fd), static_cast<uint64_t>(offset))); -#undef MMAP_SYSCALL_ARG -#else // Remaining 64-bit aritectures. - static_assert(sizeof(unsigned long) == 8, "Platform is not 64-bit"); - return reinterpret_cast<void*>( - syscall(SYS_mmap, start, length, prot, flags, fd, offset)); -#endif -} - -inline int DirectMunmap(void* start, size_t length) { - return static_cast<int>(syscall(SYS_munmap, start, length)); -} - -} // namespace base_internal -ABSL_NAMESPACE_END -} // namespace absl - -#else // !__linux__ - -// For non-linux platforms where we have mmap, just dispatch directly to the -// actual mmap()/munmap() methods. - -namespace absl { -ABSL_NAMESPACE_BEGIN -namespace base_internal { - -inline void* DirectMmap(void* start, size_t length, int prot, int flags, int fd, - off_t offset) { - return mmap(start, length, prot, flags, fd, offset); -} - -inline int DirectMunmap(void* start, size_t length) { - return munmap(start, length); -} - -} // namespace base_internal -ABSL_NAMESPACE_END -} // namespace absl - -#endif // __linux__ - -#endif // ABSL_HAVE_MMAP - -#endif // ABSL_BASE_INTERNAL_DIRECT_MMAP_H_ |