libsanitizer/sanitizer_common/sanitizer_file.cc

   1 //===-- sanitizer_file.cc ------------------------------------------------===//
   2 //
   3 // This file is distributed under the University of Illinois Open Source
   4 // License. See LICENSE.TXT for details.
   5 //
   6 //===---------------------------------------------------------------------===//
   7 //
   8 // This file is shared between AddressSanitizer and ThreadSanitizer
   9 // run-time libraries.  It defines filesystem-related interfaces.  This
  10 // is separate from sanitizer_common.cc so that it's simpler to disable
  11 // all the filesystem support code for a port that doesn't use it.
  12 //
  13 //===---------------------------------------------------------------------===//
  14
  15 #include "sanitizer_platform.h"
  16
  17 #if !SANITIZER_FUCHSIA
  18
  19 #include "sanitizer_common.h"
  20 #include "sanitizer_file.h"
  21
  22 namespace __sanitizer {
  23
  24 void CatastrophicErrorWrite(const char *buffer, uptr length) {
  25   WriteToFile(kStderrFd, buffer, length);
  26 }
  27
  28 StaticSpinMutex report_file_mu;
  29 ReportFile report_file = {&report_file_mu, kStderrFd, "", "", 0};
  30
  31 void RawWrite(const char *buffer) {
  32   report_file.Write(buffer, internal_strlen(buffer));
  33 }
  34
  35 void ReportFile::ReopenIfNecessary() {
  36   mu->CheckLocked();
  37   if (fd == kStdoutFd || fd == kStderrFd) return;
  38
  39   uptr pid = internal_getpid();
  40   // If in tracer, use the parent's file.
  41   if (pid == stoptheworld_tracer_pid)
  42     pid = stoptheworld_tracer_ppid;
  43   if (fd != kInvalidFd) {
  44     // If the report file is already opened by the current process,
  45     // do nothing. Otherwise the report file was opened by the parent
  46     // process, close it now.
  47     if (fd_pid == pid)
  48       return;
  49     else
  50       CloseFile(fd);
  51   }
  52
  53   const char *exe_name = GetProcessName();
  54   if (common_flags()->log_exe_name && exe_name) {
  55     internal_snprintf(full_path, kMaxPathLength, "%s.%s.%zu", path_prefix,
  56                       exe_name, pid);
  57   } else {
  58     internal_snprintf(full_path, kMaxPathLength, "%s.%zu", path_prefix, pid);
  59   }
  60   fd = OpenFile(full_path, WrOnly);
  61   if (fd == kInvalidFd) {
  62     const char *ErrorMsgPrefix = "ERROR: Can't open file: ";
  63     WriteToFile(kStderrFd, ErrorMsgPrefix, internal_strlen(ErrorMsgPrefix));
  64     WriteToFile(kStderrFd, full_path, internal_strlen(full_path));
  65     Die();
  66   }
  67   fd_pid = pid;
  68 }
  69
  70 void ReportFile::SetReportPath(const char *path) {
  71   if (!path)
  72     return;
  73   uptr len = internal_strlen(path);
  74   if (len > sizeof(path_prefix) - 100) {
  75     Report("ERROR: Path is too long: %c%c%c%c%c%c%c%c...\n",
  76            path[0], path[1], path[2], path[3],
  77            path[4], path[5], path[6], path[7]);
  78     Die();
  79   }
  80
  81   SpinMutexLock l(mu);
  82   if (fd != kStdoutFd && fd != kStderrFd && fd != kInvalidFd)
  83     CloseFile(fd);
  84   fd = kInvalidFd;
  85   if (internal_strcmp(path, "stdout") == 0) {
  86     fd = kStdoutFd;
  87   } else if (internal_strcmp(path, "stderr") == 0) {
  88     fd = kStderrFd;
  89   } else {
  90     internal_snprintf(path_prefix, kMaxPathLength, "%s", path);
  91   }
  92 }
  93
  94 bool ReadFileToBuffer(const char *file_name, char **buff, uptr *buff_size,
  95                       uptr *read_len, uptr max_len, error_t *errno_p) {
  96   uptr PageSize = GetPageSizeCached();
  97   uptr kMinFileLen = PageSize;
  98   *buff = nullptr;
  99   *buff_size = 0;
 100   *read_len = 0;
 101   // The files we usually open are not seekable, so try different buffer sizes.
 102   for (uptr size = kMinFileLen; size <= max_len; size *= 2) {
 103     fd_t fd = OpenFile(file_name, RdOnly, errno_p);
 104     if (fd == kInvalidFd) return false;
 105     UnmapOrDie(*buff, *buff_size);
 106     *buff = (char*)MmapOrDie(size, __func__);
 107     *buff_size = size;
 108     *read_len = 0;
 109     // Read up to one page at a time.
 110     bool reached_eof = false;
 111     while (*read_len + PageSize <= size) {
 112       uptr just_read;
 113       if (!ReadFromFile(fd, *buff + *read_len, PageSize, &just_read, errno_p)) {
 114         UnmapOrDie(*buff, *buff_size);
 115         return false;
 116       }
 117       if (just_read == 0) {
 118         reached_eof = true;
 119         break;
 120       }
 121       *read_len += just_read;
 122     }
 123     CloseFile(fd);
 124     if (reached_eof)  // We've read the whole file.
 125       break;
 126   }
 127   return true;
 128 }
 129
 130 static const char kPathSeparator = SANITIZER_WINDOWS ? ';' : ':';
 131
 132 char *FindPathToBinary(const char *name) {
 133   if (FileExists(name)) {
 134     return internal_strdup(name);
 135   }
 136
 137   const char *path = GetEnv("PATH");
 138   if (!path)
 139     return nullptr;
 140   uptr name_len = internal_strlen(name);
 141   InternalScopedBuffer<char> buffer(kMaxPathLength);
 142   const char *beg = path;
 143   while (true) {
 144     const char *end = internal_strchrnul(beg, kPathSeparator);
 145     uptr prefix_len = end - beg;
 146     if (prefix_len + name_len + 2 <= kMaxPathLength) {
 147       internal_memcpy(buffer.data(), beg, prefix_len);
 148       buffer[prefix_len] = '/';
 149       internal_memcpy(&buffer[prefix_len + 1], name, name_len);
 150       buffer[prefix_len + 1 + name_len] = '\0';
 151       if (FileExists(buffer.data()))
 152         return internal_strdup(buffer.data());
 153     }
 154     if (*end == '\0') break;
 155     beg = end + 1;
 156   }
 157   return nullptr;
 158 }
 159
 160 } // namespace __sanitizer
 161
 162 using namespace __sanitizer;  // NOLINT
 163
 164 extern "C" {
 165 void __sanitizer_set_report_path(const char *path) {
 166   report_file.SetReportPath(path);
 167 }
 168
 169 void __sanitizer_set_report_fd(void *fd) {
 170   report_file.fd = (fd_t)reinterpret_cast<uptr>(fd);
 171   report_file.fd_pid = internal_getpid();
 172 }
 173 } // extern "C"
 174
 175 #endif  // !SANITIZER_FUCHSIA