libsanitizer/sanitizer_common/sanitizer_linux.h

   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_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_posix.h"
  23 #include "sanitizer_platform_limits_solaris.h"
  24 #include "sanitizer_posix.h"
  25
  26 struct link_map;  // Opaque type returned by dlopen().
  27 struct utsname;
  28
  29 namespace __sanitizer {
  30 // Dirent structure for getdents(). Note that this structure is different from
  31 // the one in <dirent.h>, which is used by readdir().
  32 struct linux_dirent;
  33
  34 struct ProcSelfMapsBuff {
  35   char *data;
  36   uptr mmaped_size;
  37   uptr len;
  38 };
  39
  40 struct MemoryMappingLayoutData {
  41   ProcSelfMapsBuff proc_self_maps;
  42   const char *current;
  43 };
  44
  45 void ReadProcMaps(ProcSelfMapsBuff *proc_maps);
  46
  47 // Syscall wrappers.
  48 uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count);
  49 uptr internal_sigaltstack(const void* ss, void* oss);
  50 uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set,
  51     __sanitizer_sigset_t *oldset);
  52
  53 void SetSigProcMask(__sanitizer_sigset_t *set, __sanitizer_sigset_t *oldset);
  54 void BlockSignals(__sanitizer_sigset_t *oldset = nullptr);
  55 struct ScopedBlockSignals {
  56   explicit ScopedBlockSignals(__sanitizer_sigset_t *copy);
  57   ~ScopedBlockSignals();
  58
  59   ScopedBlockSignals &operator=(const ScopedBlockSignals &) = delete;
  60   ScopedBlockSignals(const ScopedBlockSignals &) = delete;
  61
  62  private:
  63   __sanitizer_sigset_t saved_;
  64 };
  65
  66 #  if SANITIZER_GLIBC
  67 uptr internal_clock_gettime(__sanitizer_clockid_t clk_id, void *tp);
  68 #endif
  69
  70 // Linux-only syscalls.
  71 #if SANITIZER_LINUX
  72 uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5);
  73 #    if defined(__x86_64__)
  74 uptr internal_arch_prctl(int option, uptr arg2);
  75 #    endif
  76 // Used only by sanitizer_stoptheworld. Signal handlers that are actually used
  77 // (like the process-wide error reporting SEGV handler) must use
  78 // internal_sigaction instead.
  79 int internal_sigaction_norestorer(int signum, const void *act, void *oldact);
  80 void internal_sigdelset(__sanitizer_sigset_t *set, int signum);
  81 #    if defined(__x86_64__) || defined(__mips__) || defined(__aarch64__) || \
  82         defined(__powerpc64__) || defined(__s390__) || defined(__i386__) || \
  83         defined(__arm__) || SANITIZER_RISCV64 || SANITIZER_LOONGARCH64
  84 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
  85                     int *parent_tidptr, void *newtls, int *child_tidptr);
  86 #endif
  87 int internal_uname(struct utsname *buf);
  88 #elif SANITIZER_FREEBSD
  89 uptr internal_procctl(int type, int id, int cmd, void *data);
  90 void internal_sigdelset(__sanitizer_sigset_t *set, int signum);
  91 #elif SANITIZER_NETBSD
  92 void internal_sigdelset(__sanitizer_sigset_t *set, int signum);
  93 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg);
  94 #endif  // SANITIZER_LINUX
  95
  96 // This class reads thread IDs from /proc/<pid>/task using only syscalls.
  97 class ThreadLister {
  98  public:
  99   explicit ThreadLister(pid_t pid);
 100   ~ThreadLister();
 101   enum Result {
 102     Error,
 103     Incomplete,
 104     Ok,
 105   };
 106   Result ListThreads(InternalMmapVector<tid_t> *threads);
 107
 108  private:
 109   bool IsAlive(int tid);
 110
 111   pid_t pid_;
 112   int descriptor_ = -1;
 113   InternalMmapVector<char> buffer_;
 114 };
 115
 116 // Exposed for testing.
 117 uptr ThreadDescriptorSize();
 118 uptr ThreadSelf();
 119
 120 // Matches a library's file name against a base name (stripping path and version
 121 // information).
 122 bool LibraryNameIs(const char *full_name, const char *base_name);
 123
 124 // Call cb for each region mapped by map.
 125 void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr));
 126
 127 // Releases memory pages entirely within the [beg, end] address range.
 128 // The pages no longer count toward RSS; reads are guaranteed to return 0.
 129 // Requires (but does not verify!) that pages are MAP_PRIVATE.
 130 inline void ReleaseMemoryPagesToOSAndZeroFill(uptr beg, uptr end) {
 131   // man madvise on Linux promises zero-fill for anonymous private pages.
 132   // Testing shows the same behaviour for private (but not anonymous) mappings
 133   // of shm_open() files, as long as the underlying file is untouched.
 134   CHECK(SANITIZER_LINUX);
 135   ReleaseMemoryPagesToOS(beg, end);
 136 }
 137
 138 #if SANITIZER_ANDROID
 139
 140 #if defined(__aarch64__)
 141 # define __get_tls() \
 142     ({ void** __v; __asm__("mrs %0, tpidr_el0" : "=r"(__v)); __v; })
 143 #elif defined(__arm__)
 144 # define __get_tls() \
 145     ({ void** __v; __asm__("mrc p15, 0, %0, c13, c0, 3" : "=r"(__v)); __v; })
 146 #elif defined(__mips__)
 147 // On mips32r1, this goes via a kernel illegal instruction trap that's
 148 // optimized for v1.
 149 # define __get_tls() \
 150     ({ register void** __v asm("v1"); \
 151        __asm__(".set    push\n" \
 152                ".set    mips32r2\n" \
 153                "rdhwr   %0,$29\n" \
 154                ".set    pop\n" : "=r"(__v)); \
 155        __v; })
 156 #elif defined (__riscv)
 157 # define __get_tls() \
 158     ({ void** __v; __asm__("mv %0, tp" : "=r"(__v)); __v; })
 159 #elif defined(__i386__)
 160 # define __get_tls() \
 161     ({ void** __v; __asm__("movl %%gs:0, %0" : "=r"(__v)); __v; })
 162 #elif defined(__x86_64__)
 163 # define __get_tls() \
 164     ({ void** __v; __asm__("mov %%fs:0, %0" : "=r"(__v)); __v; })
 165 #else
 166 #error "Unsupported architecture."
 167 #endif
 168
 169 // The Android Bionic team has allocated a TLS slot for sanitizers starting
 170 // with Q, given that Android currently doesn't support ELF TLS. It is used to
 171 // store sanitizer thread specific data.
 172 static const int TLS_SLOT_SANITIZER = 6;
 173
 174 ALWAYS_INLINE uptr *get_android_tls_ptr() {
 175   return reinterpret_cast<uptr *>(&__get_tls()[TLS_SLOT_SANITIZER]);
 176 }
 177
 178 #endif  // SANITIZER_ANDROID
 179
 180 }  // namespace __sanitizer
 181
 182 #endif
 183 #endif  // SANITIZER_LINUX_H