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