1//===-- sanitizer_linux.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// Linux-specific syscall wrappers and classes. 10// 11//===----------------------------------------------------------------------===// 12#ifndef SANITIZER_LINUX_H 13#define SANITIZER_LINUX_H 14 15#include "sanitizer_platform.h" 16#if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \ 17 SANITIZER_OPENBSD || SANITIZER_SOLARIS 18#include "sanitizer_common.h" 19#include "sanitizer_internal_defs.h" 20#include "sanitizer_platform_limits_freebsd.h" 21#include "sanitizer_platform_limits_netbsd.h" 22#include "sanitizer_platform_limits_openbsd.h" 23#include "sanitizer_platform_limits_posix.h" 24#include "sanitizer_platform_limits_solaris.h" 25#include "sanitizer_posix.h" 26 27struct link_map; // Opaque type returned by dlopen(). 28 29namespace __sanitizer { 30// Dirent structure for getdents(). Note that this structure is different from 31// the one in <dirent.h>, which is used by readdir(). 32struct linux_dirent; 33 34struct ProcSelfMapsBuff { 35 char *data; 36 uptr mmaped_size; 37 uptr len; 38}; 39 40struct MemoryMappingLayoutData { 41 ProcSelfMapsBuff proc_self_maps; 42 const char *current; 43}; 44 45void ReadProcMaps(ProcSelfMapsBuff *proc_maps); 46 47// Syscall wrappers. 48uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count); 49uptr internal_sigaltstack(const void* ss, void* oss); 50uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set, 51 __sanitizer_sigset_t *oldset); 52uptr internal_clock_gettime(__sanitizer_clockid_t clk_id, void *tp); 53 54// Linux-only syscalls. 55#if SANITIZER_LINUX 56uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5); 57// Used only by sanitizer_stoptheworld. Signal handlers that are actually used 58// (like the process-wide error reporting SEGV handler) must use 59// internal_sigaction instead. 60int internal_sigaction_norestorer(int signum, const void *act, void *oldact); 61void internal_sigdelset(__sanitizer_sigset_t *set, int signum); 62#if defined(__x86_64__) || defined(__mips__) || defined(__aarch64__) \ 63 || defined(__powerpc64__) || defined(__s390__) || defined(__i386__) \ 64 || defined(__arm__) 65uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg, 66 int *parent_tidptr, void *newtls, int *child_tidptr); 67#endif 68#elif SANITIZER_FREEBSD 69void internal_sigdelset(__sanitizer_sigset_t *set, int signum); 70#elif SANITIZER_NETBSD 71void internal_sigdelset(__sanitizer_sigset_t *set, int signum); 72uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg); 73#endif // SANITIZER_LINUX 74 75// This class reads thread IDs from /proc/<pid>/task using only syscalls. 76class ThreadLister { 77 public: 78 explicit ThreadLister(pid_t pid); 79 ~ThreadLister(); 80 enum Result { 81 Error, 82 Incomplete, 83 Ok, 84 }; 85 Result ListThreads(InternalMmapVector<tid_t> *threads); 86 87 private: 88 bool IsAlive(int tid); 89 90 pid_t pid_; 91 int descriptor_ = -1; 92 InternalMmapVector<char> buffer_; 93}; 94 95// Exposed for testing. 96uptr ThreadDescriptorSize(); 97uptr ThreadSelf(); 98uptr ThreadSelfOffset(); 99 100// Matches a library's file name against a base name (stripping path and version 101// information). 102bool LibraryNameIs(const char *full_name, const char *base_name); 103 104// Call cb for each region mapped by map. 105void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr)); 106 107// Releases memory pages entirely within the [beg, end] address range. 108// The pages no longer count toward RSS; reads are guaranteed to return 0. 109// Requires (but does not verify!) that pages are MAP_PRIVATE. 110INLINE void ReleaseMemoryPagesToOSAndZeroFill(uptr beg, uptr end) { 111 // man madvise on Linux promises zero-fill for anonymous private pages. 112 // Testing shows the same behaviour for private (but not anonymous) mappings 113 // of shm_open() files, as long as the underlying file is untouched. 114 CHECK(SANITIZER_LINUX); 115 ReleaseMemoryPagesToOS(beg, end); 116} 117 118#if SANITIZER_ANDROID 119 120#if defined(__aarch64__) 121# define __get_tls() \ 122 ({ void** __v; __asm__("mrs %0, tpidr_el0" : "=r"(__v)); __v; }) 123#elif defined(__arm__) 124# define __get_tls() \ 125 ({ void** __v; __asm__("mrc p15, 0, %0, c13, c0, 3" : "=r"(__v)); __v; }) 126#elif defined(__mips__) 127// On mips32r1, this goes via a kernel illegal instruction trap that's 128// optimized for v1. 129# define __get_tls() \ 130 ({ register void** __v asm("v1"); \ 131 __asm__(".set push\n" \ 132 ".set mips32r2\n" \ 133 "rdhwr %0,$29\n" \ 134 ".set pop\n" : "=r"(__v)); \ 135 __v; }) 136#elif defined(__i386__) 137# define __get_tls() \ 138 ({ void** __v; __asm__("movl %%gs:0, %0" : "=r"(__v)); __v; }) 139#elif defined(__x86_64__) 140# define __get_tls() \ 141 ({ void** __v; __asm__("mov %%fs:0, %0" : "=r"(__v)); __v; }) 142#else 143#error "Unsupported architecture." 144#endif 145 146// The Android Bionic team has allocated a TLS slot for sanitizers starting 147// with Q, given that Android currently doesn't support ELF TLS. It is used to 148// store sanitizer thread specific data. 149static const int TLS_SLOT_SANITIZER = 6; 150 151ALWAYS_INLINE uptr *get_android_tls_ptr() { 152 return reinterpret_cast<uptr *>(&__get_tls()[TLS_SLOT_SANITIZER]); 153} 154 155#endif // SANITIZER_ANDROID 156 157} // namespace __sanitizer 158 159#endif 160#endif // SANITIZER_LINUX_H 161