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 uptr internal_clock_gettime(__sanitizer_clockid_t clk_id, void *tp);
  53
  54 // Linux-only syscalls.
  55 #if SANITIZER_LINUX
  56 uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5);
  57 // Used only by sanitizer_stoptheworld. Signal handlers that are actually used
  58 // (like the process-wide error reporting SEGV handler) must use
  59 // internal_sigaction instead.
  60 int internal_sigaction_norestorer(int signum, const void *act, void *oldact);
  61 void internal_sigdelset(__sanitizer_sigset_t *set, int signum);
  62 #if defined(__x86_64__) || defined(__mips__) || defined(__aarch64__) || \
  63     defined(__powerpc64__) || defined(__s390__) || defined(__i386__) || \
  64     defined(__arm__) || SANITIZER_RISCV64
  65 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
  66                     int *parent_tidptr, void *newtls, int *child_tidptr);
  67 #endif
  68 int internal_uname(struct utsname *buf);
  69 #elif SANITIZER_FREEBSD
  70 void internal_sigdelset(__sanitizer_sigset_t *set, int signum);
  71 #elif SANITIZER_NETBSD
  72 void internal_sigdelset(__sanitizer_sigset_t *set, int signum);
  73 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg);
  74 #endif  // SANITIZER_LINUX
  75
  76 // This class reads thread IDs from /proc/<pid>/task using only syscalls.
  77 class ThreadLister {
  78  public:
  79   explicit ThreadLister(pid_t pid);
  80   ~ThreadLister();
  81   enum Result {
  82     Error,
  83     Incomplete,
  84     Ok,
  85   };
  86   Result ListThreads(InternalMmapVector<tid_t> *threads);
  87
  88  private:
  89   bool IsAlive(int tid);
  90
  91   pid_t pid_;
  92   int descriptor_ = -1;
  93   InternalMmapVector<char> buffer_;
  94 };
  95
  96 // Exposed for testing.
  97 uptr ThreadDescriptorSize();
  98 uptr ThreadSelf();
  99 uptr ThreadSelfOffset();
 100
 101 // Matches a library's file name against a base name (stripping path and version
 102 // information).
 103 bool LibraryNameIs(const char *full_name, const char *base_name);
 104
 105 // Call cb for each region mapped by map.
 106 void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr));
 107
 108 // Releases memory pages entirely within the [beg, end] address range.
 109 // The pages no longer count toward RSS; reads are guaranteed to return 0.
 110 // Requires (but does not verify!) that pages are MAP_PRIVATE.
 111 inline void ReleaseMemoryPagesToOSAndZeroFill(uptr beg, uptr end) {
 112   // man madvise on Linux promises zero-fill for anonymous private pages.
 113   // Testing shows the same behaviour for private (but not anonymous) mappings
 114   // of shm_open() files, as long as the underlying file is untouched.
 115   CHECK(SANITIZER_LINUX);
 116   ReleaseMemoryPagesToOS(beg, end);
 117 }
 118
 119 #if SANITIZER_ANDROID
 120
 121 #if defined(__aarch64__)
 122 # define __get_tls() \
 123     ({ void** __v; __asm__("mrs %0, tpidr_el0" : "=r"(__v)); __v; })
 124 #elif defined(__arm__)
 125 # define __get_tls() \
 126     ({ void** __v; __asm__("mrc p15, 0, %0, c13, c0, 3" : "=r"(__v)); __v; })
 127 #elif defined(__mips__)
 128 // On mips32r1, this goes via a kernel illegal instruction trap that's
 129 // optimized for v1.
 130 # define __get_tls() \
 131     ({ register void** __v asm("v1"); \
 132        __asm__(".set    push\n" \
 133                ".set    mips32r2\n" \
 134                "rdhwr   %0,$29\n" \
 135                ".set    pop\n" : "=r"(__v)); \
 136        __v; })
 137 #elif defined(__i386__)
 138 # define __get_tls() \
 139     ({ void** __v; __asm__("movl %%gs:0, %0" : "=r"(__v)); __v; })
 140 #elif defined(__x86_64__)
 141 # define __get_tls() \
 142     ({ void** __v; __asm__("mov %%fs:0, %0" : "=r"(__v)); __v; })
 143 #else
 144 #error "Unsupported architecture."
 145 #endif
 146
 147 // The Android Bionic team has allocated a TLS slot for sanitizers starting
 148 // with Q, given that Android currently doesn't support ELF TLS. It is used to
 149 // store sanitizer thread specific data.
 150 static const int TLS_SLOT_SANITIZER = 6;
 151
 152 ALWAYS_INLINE uptr *get_android_tls_ptr() {
 153   return reinterpret_cast<uptr *>(&__get_tls()[TLS_SLOT_SANITIZER]);
 154 }
 155
 156 #endif  // SANITIZER_ANDROID
 157
 158 }  // namespace __sanitizer
 159
 160 #endif
 161 #endif  // SANITIZER_LINUX_H