1 //===-- sanitizer_linux.h ---------------------------------------*- C++ -*-===// 2 // 3 // This file is distributed under the University of Illinois Open Source 4 // License. See LICENSE.TXT for details. 5 // 6 //===----------------------------------------------------------------------===// 7 // 8 // Linux-specific syscall wrappers and classes. 9 // 10 //===----------------------------------------------------------------------===// 11 #ifndef SANITIZER_LINUX_H 12 #define SANITIZER_LINUX_H 13 14 #include "sanitizer_platform.h" 15 #if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD 16 #include "sanitizer_common.h" 17 #include "sanitizer_internal_defs.h" 18 #include "sanitizer_platform_limits_netbsd.h" 19 #include "sanitizer_platform_limits_posix.h" 20 #include "sanitizer_posix.h" 21 22 struct link_map; // Opaque type returned by dlopen(). 23 24 namespace __sanitizer { 25 // Dirent structure for getdents(). Note that this structure is different from 26 // the one in <dirent.h>, which is used by readdir(). 27 struct linux_dirent; 28 29 struct ProcSelfMapsBuff { 30 char *data; 31 uptr mmaped_size; 32 uptr len; 33 }; 34 35 struct MemoryMappingLayoutData { 36 ProcSelfMapsBuff proc_self_maps; 37 const char *current; 38 }; 39 40 void ReadProcMaps(ProcSelfMapsBuff *proc_maps); 41 42 // Syscall wrappers. 43 uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count); 44 uptr internal_sigaltstack(const void* ss, void* oss); 45 uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set, 46 __sanitizer_sigset_t *oldset); 47 48 // Linux-only syscalls. 49 #if SANITIZER_LINUX 50 uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5); 51 // Used only by sanitizer_stoptheworld. Signal handlers that are actually used 52 // (like the process-wide error reporting SEGV handler) must use 53 // internal_sigaction instead. 54 int internal_sigaction_norestorer(int signum, const void *act, void *oldact); 55 #if (defined(__x86_64__) || SANITIZER_MIPS64) && !SANITIZER_GO 56 // Uses a raw system call to avoid interceptors. 57 int internal_sigaction_syscall(int signum, const void *act, void *oldact); 58 #endif 59 void internal_sigdelset(__sanitizer_sigset_t *set, int signum); 60 #if defined(__x86_64__) || defined(__mips__) || defined(__aarch64__) \ 61 || defined(__powerpc64__) || defined(__s390__) || defined(__i386__) \ 62 || defined(__arm__) 63 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg, 64 int *parent_tidptr, void *newtls, int *child_tidptr); 65 #endif 66 #endif // SANITIZER_LINUX 67 68 #ifdef SANITIZER_NETBSD 69 int internal_sigaction_norestorer(int signum, const void *act, void *oldact); 70 #define internal_sigdelset(set, signum) \ 71 __sigdelset(set, signum) 72 #define internal_clone(fn, child_stack, flags, arg, \ 73 parent_tidptr, newtls, child_tidptr) \ 74 __clone(fn, child_stack, flags, arg) 75 #endif 76 77 // This class reads thread IDs from /proc/<pid>/task using only syscalls. 78 class ThreadLister { 79 public: 80 explicit ThreadLister(int pid); 81 ~ThreadLister(); 82 // GetNextTID returns -1 if the list of threads is exhausted, or if there has 83 // been an error. 84 int GetNextTID(); 85 void Reset(); 86 bool error(); 87 88 private: 89 bool GetDirectoryEntries(); 90 91 int pid_; 92 int descriptor_; 93 InternalScopedBuffer<char> buffer_; 94 bool error_; 95 struct linux_dirent* entry_; 96 int bytes_read_; 97 }; 98 99 // Exposed for testing. 100 uptr ThreadDescriptorSize(); 101 uptr ThreadSelf(); 102 uptr ThreadSelfOffset(); 103 104 // Matches a library's file name against a base name (stripping path and version 105 // information). 106 bool LibraryNameIs(const char *full_name, const char *base_name); 107 108 // Call cb for each region mapped by map. 109 void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr)); 110 111 #if SANITIZER_ANDROID 112 113 #if defined(__aarch64__) 114 # define __get_tls() \ 115 ({ void** __v; __asm__("mrs %0, tpidr_el0" : "=r"(__v)); __v; }) 116 #elif defined(__arm__) 117 # define __get_tls() \ 118 ({ void** __v; __asm__("mrc p15, 0, %0, c13, c0, 3" : "=r"(__v)); __v; }) 119 #elif defined(__mips__) 120 // On mips32r1, this goes via a kernel illegal instruction trap that's 121 // optimized for v1. 122 # define __get_tls() \ 123 ({ register void** __v asm("v1"); \ 124 __asm__(".set push\n" \ 125 ".set mips32r2\n" \ 126 "rdhwr %0,$29\n" \ 127 ".set pop\n" : "=r"(__v)); \ 128 __v; }) 129 #elif defined(__i386__) 130 # define __get_tls() \ 131 ({ void** __v; __asm__("movl %%gs:0, %0" : "=r"(__v)); __v; }) 132 #elif defined(__x86_64__) 133 # define __get_tls() \ 134 ({ void** __v; __asm__("mov %%fs:0, %0" : "=r"(__v)); __v; }) 135 #else 136 #error "Unsupported architecture." 137 #endif 138 139 // The Android Bionic team has allocated a TLS slot for TSan starting with N, 140 // given that Android currently doesn't support ELF TLS. It is used to store 141 // Sanitizers thread specific data. 142 static const int TLS_SLOT_TSAN = 8; 143 144 ALWAYS_INLINE uptr *get_android_tls_ptr() { 145 return reinterpret_cast<uptr *>(&__get_tls()[TLS_SLOT_TSAN]); 146 } 147 148 #endif // SANITIZER_ANDROID 149 150 } // namespace __sanitizer 151 152 #endif // SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD 153 #endif // SANITIZER_LINUX_H 154