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