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 SANITIZER_OPENBSD || SANITIZER_SOLARIS 17 #include "sanitizer_common.h" 18 #include "sanitizer_internal_defs.h" 19 #include "sanitizer_platform_limits_netbsd.h" 20 #include "sanitizer_platform_limits_openbsd.h" 21 #include "sanitizer_platform_limits_posix.h" 22 #include "sanitizer_platform_limits_solaris.h" 23 #include "sanitizer_posix.h" 24 25 struct link_map; // Opaque type returned by dlopen(). 26 27 namespace __sanitizer { 28 // Dirent structure for getdents(). Note that this structure is different from 29 // the one in <dirent.h>, which is used by readdir(). 30 struct linux_dirent; 31 32 struct ProcSelfMapsBuff { 33 char *data; 34 uptr mmaped_size; 35 uptr len; 36 }; 37 38 struct MemoryMappingLayoutData { 39 ProcSelfMapsBuff proc_self_maps; 40 const char *current; 41 }; 42 43 void ReadProcMaps(ProcSelfMapsBuff *proc_maps); 44 45 // Syscall wrappers. 46 uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count); 47 uptr internal_sigaltstack(const void* ss, void* oss); 48 uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set, 49 __sanitizer_sigset_t *oldset); 50 uptr internal_clock_gettime(__sanitizer_clockid_t clk_id, void *tp); 51 52 // Linux-only syscalls. 53 #if SANITIZER_LINUX 54 uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5); 55 // Used only by sanitizer_stoptheworld. Signal handlers that are actually used 56 // (like the process-wide error reporting SEGV handler) must use 57 // internal_sigaction instead. 58 int internal_sigaction_norestorer(int signum, const void *act, void *oldact); 59 #if (defined(__x86_64__) || SANITIZER_MIPS64) && !SANITIZER_GO 60 // Uses a raw system call to avoid interceptors. 61 int internal_sigaction_syscall(int signum, const void *act, void *oldact); 62 #endif 63 void internal_sigdelset(__sanitizer_sigset_t *set, int signum); 64 #if defined(__x86_64__) || defined(__mips__) || defined(__aarch64__) \ 65 || defined(__powerpc64__) || defined(__s390__) || defined(__i386__) \ 66 || defined(__arm__) 67 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg, 68 int *parent_tidptr, void *newtls, int *child_tidptr); 69 #endif 70 #elif SANITIZER_FREEBSD 71 void internal_sigdelset(__sanitizer_sigset_t *set, int signum); 72 #elif SANITIZER_NETBSD 73 uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5); 74 #endif // SANITIZER_LINUX 75 76 #ifdef SANITIZER_NETBSD 77 void internal_sigdelset(__sanitizer_sigset_t *set, int signum); 78 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg); 79 #endif 80 81 // This class reads thread IDs from /proc/<pid>/task using only syscalls. 82 class ThreadLister { 83 public: 84 explicit ThreadLister(pid_t pid); 85 ~ThreadLister(); 86 enum Result { 87 Error, 88 Incomplete, 89 Ok, 90 }; 91 Result ListThreads(InternalMmapVector<tid_t> *threads); 92 93 private: 94 bool IsAlive(int tid); 95 96 pid_t pid_; 97 int descriptor_ = -1; 98 InternalMmapVector<char> buffer_; 99 }; 100 101 // Exposed for testing. 102 uptr ThreadDescriptorSize(); 103 uptr ThreadSelf(); 104 uptr ThreadSelfOffset(); 105 106 // Matches a library's file name against a base name (stripping path and version 107 // information). 108 bool LibraryNameIs(const char *full_name, const char *base_name); 109 110 // Call cb for each region mapped by map. 111 void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr)); 112 113 #if SANITIZER_ANDROID 114 115 #if defined(__aarch64__) 116 # define __get_tls() \ 117 ({ void** __v; __asm__("mrs %0, tpidr_el0" : "=r"(__v)); __v; }) 118 #elif defined(__arm__) 119 # define __get_tls() \ 120 ({ void** __v; __asm__("mrc p15, 0, %0, c13, c0, 3" : "=r"(__v)); __v; }) 121 #elif defined(__mips__) 122 // On mips32r1, this goes via a kernel illegal instruction trap that's 123 // optimized for v1. 124 # define __get_tls() \ 125 ({ register void** __v asm("v1"); \ 126 __asm__(".set push\n" \ 127 ".set mips32r2\n" \ 128 "rdhwr %0,$29\n" \ 129 ".set pop\n" : "=r"(__v)); \ 130 __v; }) 131 #elif defined(__i386__) 132 # define __get_tls() \ 133 ({ void** __v; __asm__("movl %%gs:0, %0" : "=r"(__v)); __v; }) 134 #elif defined(__x86_64__) 135 # define __get_tls() \ 136 ({ void** __v; __asm__("mov %%fs:0, %0" : "=r"(__v)); __v; }) 137 #else 138 #error "Unsupported architecture." 139 #endif 140 141 // The Android Bionic team has allocated a TLS slot for TSan starting with N, 142 // given that Android currently doesn't support ELF TLS. It is used to store 143 // Sanitizers thread specific data. 144 static const int TLS_SLOT_TSAN = 8; 145 146 ALWAYS_INLINE uptr *get_android_tls_ptr() { 147 return reinterpret_cast<uptr *>(&__get_tls()[TLS_SLOT_TSAN]); 148 } 149 150 #endif // SANITIZER_ANDROID 151 152 } // namespace __sanitizer 153 154 #endif 155 #endif // SANITIZER_LINUX_H 156