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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-exception6//7//===----------------------------------------------------------------------===//8//9// Linux-specific syscall wrappers and classes.10//11//===----------------------------------------------------------------------===//12#ifndef SANITIZER_LINUX_H13#define SANITIZER_LINUX_H14 15#include "sanitizer_platform.h"16#if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \17 SANITIZER_SOLARIS || SANITIZER_HAIKU18# 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_posix.h"23# include "sanitizer_platform_limits_solaris.h"24# include "sanitizer_posix.h"25 26struct link_map; // Opaque type returned by dlopen().27struct utsname;28 29namespace __sanitizer {30// Dirent structure for getdents(). Note that this structure is different from31// the one in <dirent.h>, which is used by readdir().32struct linux_dirent;33 34# if SANITIZER_HAIKU35struct MemoryMappingLayoutData {36 long signed int cookie;37};38# else39struct ProcSelfMapsBuff {40 char *data;41 uptr mmaped_size;42 uptr len;43};44 45struct MemoryMappingLayoutData {46 ProcSelfMapsBuff proc_self_maps;47 const char *current;48};49 50void ReadProcMaps(ProcSelfMapsBuff *proc_maps);51# endif // SANITIZER_HAIKU52 53// Syscall wrappers.54uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count);55uptr internal_sigaltstack(const void *ss, void *oss);56uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set,57 __sanitizer_sigset_t *oldset);58 59void SetSigProcMask(__sanitizer_sigset_t *set, __sanitizer_sigset_t *oldset);60void BlockSignals(__sanitizer_sigset_t *oldset = nullptr);61struct ScopedBlockSignals {62 explicit ScopedBlockSignals(__sanitizer_sigset_t *copy);63 ~ScopedBlockSignals();64 65 ScopedBlockSignals &operator=(const ScopedBlockSignals &) = delete;66 ScopedBlockSignals(const ScopedBlockSignals &) = delete;67 68 private:69 __sanitizer_sigset_t saved_;70};71 72# if SANITIZER_GLIBC73uptr internal_clock_gettime(__sanitizer_clockid_t clk_id, void *tp);74# endif75 76// Linux-only syscalls.77# if SANITIZER_LINUX78uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5);79# if defined(__x86_64__)80uptr internal_arch_prctl(int option, uptr arg2);81# endif82// Used only by sanitizer_stoptheworld. Signal handlers that are actually used83// (like the process-wide error reporting SEGV handler) must use84// internal_sigaction instead.85int internal_sigaction_norestorer(int signum, const void *act, void *oldact);86void internal_sigdelset(__sanitizer_sigset_t *set, int signum);87# if defined(__x86_64__) || defined(__mips__) || defined(__aarch64__) || \88 defined(__powerpc64__) || defined(__s390__) || defined(__i386__) || \89 defined(__arm__) || SANITIZER_RISCV64 || SANITIZER_LOONGARCH6490uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,91 int *parent_tidptr, void *newtls, int *child_tidptr);92# endif93int internal_uname(struct utsname *buf);94# elif SANITIZER_FREEBSD95uptr internal_procctl(int type, int id, int cmd, void *data);96void internal_sigdelset(__sanitizer_sigset_t *set, int signum);97# elif SANITIZER_NETBSD98void internal_sigdelset(__sanitizer_sigset_t *set, int signum);99uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg);100# endif // SANITIZER_LINUX101 102// This class reads thread IDs from /proc/<pid>/task using only syscalls.103class ThreadLister {104 public:105 explicit ThreadLister(pid_t pid);106 enum Result {107 Error,108 Incomplete,109 Ok,110 };111 Result ListThreads(InternalMmapVector<ThreadID> *threads);112 const char *LoadStatus(ThreadID tid);113 114 private:115 bool IsAlive(ThreadID tid);116 117 InternalScopedString task_path_;118 InternalScopedString status_path_;119 InternalMmapVector<char> buffer_;120};121 122// Exposed for testing.123uptr ThreadDescriptorSize();124uptr ThreadSelf();125 126// Matches a library's file name against a base name (stripping path and version127// information).128bool LibraryNameIs(const char *full_name, const char *base_name);129 130// Call cb for each region mapped by map.131void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr));132 133// Releases memory pages entirely within the [beg, end) address range.134// The pages no longer count toward RSS; reads are guaranteed to return 0.135// Requires (but does not verify!) that pages are MAP_PRIVATE.136inline void ReleaseMemoryPagesToOSAndZeroFill(uptr beg, uptr end) {137 // man madvise on Linux promises zero-fill for anonymous private pages.138 // Testing shows the same behaviour for private (but not anonymous) mappings139 // of shm_open() files, as long as the underlying file is untouched.140 CHECK(SANITIZER_LINUX);141 ReleaseMemoryPagesToOS(beg, end);142}143 144# if SANITIZER_ANDROID145 146# if defined(__aarch64__)147# define __get_tls() \148 ({ \149 void **__v; \150 __asm__("mrs %0, tpidr_el0" : "=r"(__v)); \151 __v; \152 })153# elif defined(__arm__)154# define __get_tls() \155 ({ \156 void **__v; \157 __asm__("mrc p15, 0, %0, c13, c0, 3" : "=r"(__v)); \158 __v; \159 })160# elif defined(__mips__)161// On mips32r1, this goes via a kernel illegal instruction trap that's162// optimized for v1.163# define __get_tls() \164 ({ \165 register void **__v asm("v1"); \166 __asm__( \167 ".set push\n" \168 ".set mips32r2\n" \169 "rdhwr %0,$29\n" \170 ".set pop\n" \171 : "=r"(__v)); \172 __v; \173 })174# elif defined(__riscv)175# define __get_tls() \176 ({ \177 void **__v; \178 __asm__("mv %0, tp" : "=r"(__v)); \179 __v; \180 })181# elif defined(__i386__)182# define __get_tls() \183 ({ \184 void **__v; \185 __asm__("movl %%gs:0, %0" : "=r"(__v)); \186 __v; \187 })188# elif defined(__x86_64__)189# define __get_tls() \190 ({ \191 void **__v; \192 __asm__("mov %%fs:0, %0" : "=r"(__v)); \193 __v; \194 })195# else196# error "Unsupported architecture."197# endif198 199// The Android Bionic team has allocated a TLS slot for sanitizers starting200// with Q, given that Android currently doesn't support ELF TLS. It is used to201// store sanitizer thread specific data.202static const int TLS_SLOT_SANITIZER = 6;203 204ALWAYS_INLINE uptr *get_android_tls_ptr() {205 return reinterpret_cast<uptr *>(&__get_tls()[TLS_SLOT_SANITIZER]);206}207 208# endif // SANITIZER_ANDROID209 210} // namespace __sanitizer211 212#endif213#endif // SANITIZER_LINUX_H214