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