libsanitizer/sanitizer_common/sanitizer_file.cpp

   1 //===-- sanitizer_file.cpp -----------------------------------------------===//
   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 // This file is shared between AddressSanitizer and ThreadSanitizer
  10 // run-time libraries.  It defines filesystem-related interfaces.  This
  11 // is separate from sanitizer_common.cpp so that it's simpler to disable
  12 // all the filesystem support code for a port that doesn't use it.
  13 //
  14 //===---------------------------------------------------------------------===//
  15
  16 #include "sanitizer_platform.h"
  17
  18 #if !SANITIZER_FUCHSIA
  19
  20 #include "sanitizer_common.h"
  21 #include "sanitizer_file.h"
  22
  23 namespace __sanitizer {
  24
  25 void CatastrophicErrorWrite(const char *buffer, uptr length) {
  26   WriteToFile(kStderrFd, buffer, length);
  27 }
  28
  29 StaticSpinMutex report_file_mu;
  30 ReportFile report_file = {&report_file_mu, kStderrFd, "", "", 0};
  31
  32 void RawWrite(const char *buffer) {
  33   report_file.Write(buffer, internal_strlen(buffer));
  34 }
  35
  36 void ReportFile::ReopenIfNecessary() {
  37   mu->CheckLocked();
  38   if (fd == kStdoutFd || fd == kStderrFd) return;
  39
  40   uptr pid = internal_getpid();
  41   // If in tracer, use the parent's file.
  42   if (pid == stoptheworld_tracer_pid)
  43     pid = stoptheworld_tracer_ppid;
  44   if (fd != kInvalidFd) {
  45     // If the report file is already opened by the current process,
  46     // do nothing. Otherwise the report file was opened by the parent
  47     // process, close it now.
  48     if (fd_pid == pid)
  49       return;
  50     else
  51       CloseFile(fd);
  52   }
  53
  54   const char *exe_name = GetProcessName();
  55   if (common_flags()->log_exe_name && exe_name) {
  56     internal_snprintf(full_path, kMaxPathLength, "%s.%s.%zu", path_prefix,
  57                       exe_name, pid);
  58   } else {
  59     internal_snprintf(full_path, kMaxPathLength, "%s.%zu", path_prefix, pid);
  60   }
  61   if (common_flags()->log_suffix) {
  62     internal_strlcat(full_path, common_flags()->log_suffix, kMaxPathLength);
  63   }
  64   error_t err;
  65   fd = OpenFile(full_path, WrOnly, &err);
  66   if (fd == kInvalidFd) {
  67     const char *ErrorMsgPrefix = "ERROR: Can't open file: ";
  68     WriteToFile(kStderrFd, ErrorMsgPrefix, internal_strlen(ErrorMsgPrefix));
  69     WriteToFile(kStderrFd, full_path, internal_strlen(full_path));
  70     char errmsg[100];
  71     internal_snprintf(errmsg, sizeof(errmsg), " (reason: %d)", err);
  72     WriteToFile(kStderrFd, errmsg, internal_strlen(errmsg));
  73     Die();
  74   }
  75   fd_pid = pid;
  76 }
  77
  78 static void RecursiveCreateParentDirs(char *path) {
  79   if (path[0] == '\0')
  80     return;
  81   for (int i = 1; path[i] != '\0'; ++i) {
  82     char save = path[i];
  83     if (!IsPathSeparator(path[i]))
  84       continue;
  85     path[i] = '\0';
  86     /* Some of these will fail, because the directory exists, ignore it. */
  87     CreateDir(path);
  88     path[i] = save;
  89   }
  90 }
  91
  92 void ReportFile::SetReportPath(const char *path) {
  93   if (path) {
  94     uptr len = internal_strlen(path);
  95     if (len > sizeof(path_prefix) - 100) {
  96       Report("ERROR: Path is too long: %c%c%c%c%c%c%c%c...\n", path[0], path[1],
  97              path[2], path[3], path[4], path[5], path[6], path[7]);
  98       Die();
  99     }
 100   }
 101
 102   SpinMutexLock l(mu);
 103   if (fd != kStdoutFd && fd != kStderrFd && fd != kInvalidFd)
 104     CloseFile(fd);
 105   fd = kInvalidFd;
 106   if (!path || internal_strcmp(path, "stderr") == 0) {
 107     fd = kStderrFd;
 108   } else if (internal_strcmp(path, "stdout") == 0) {
 109     fd = kStdoutFd;
 110   } else {
 111     internal_snprintf(path_prefix, kMaxPathLength, "%s", path);
 112     RecursiveCreateParentDirs(path_prefix);
 113   }
 114 }
 115
 116 const char *ReportFile::GetReportPath() {
 117   SpinMutexLock l(mu);
 118   ReopenIfNecessary();
 119   return full_path;
 120 }
 121
 122 bool ReadFileToBuffer(const char *file_name, char **buff, uptr *buff_size,
 123                       uptr *read_len, uptr max_len, error_t *errno_p) {
 124   *buff = nullptr;
 125   *buff_size = 0;
 126   *read_len = 0;
 127   if (!max_len)
 128     return true;
 129   uptr PageSize = GetPageSizeCached();
 130   uptr kMinFileLen = Min(PageSize, max_len);
 131
 132   // The files we usually open are not seekable, so try different buffer sizes.
 133   for (uptr size = kMinFileLen;; size = Min(size * 2, max_len)) {
 134     UnmapOrDie(*buff, *buff_size);
 135     *buff = (char*)MmapOrDie(size, __func__);
 136     *buff_size = size;
 137     fd_t fd = OpenFile(file_name, RdOnly, errno_p);
 138     if (fd == kInvalidFd) {
 139       UnmapOrDie(*buff, *buff_size);
 140       return false;
 141     }
 142     *read_len = 0;
 143     // Read up to one page at a time.
 144     bool reached_eof = false;
 145     while (*read_len < size) {
 146       uptr just_read;
 147       if (!ReadFromFile(fd, *buff + *read_len, size - *read_len, &just_read,
 148                         errno_p)) {
 149         UnmapOrDie(*buff, *buff_size);
 150         CloseFile(fd);
 151         return false;
 152       }
 153       *read_len += just_read;
 154       if (just_read == 0 || *read_len == max_len) {
 155         reached_eof = true;
 156         break;
 157       }
 158     }
 159     CloseFile(fd);
 160     if (reached_eof)  // We've read the whole file.
 161       break;
 162   }
 163   return true;
 164 }
 165
 166 bool ReadFileToVector(const char *file_name,
 167                       InternalMmapVectorNoCtor<char> *buff, uptr max_len,
 168                       error_t *errno_p) {
 169   buff->clear();
 170   if (!max_len)
 171     return true;
 172   uptr PageSize = GetPageSizeCached();
 173   fd_t fd = OpenFile(file_name, RdOnly, errno_p);
 174   if (fd == kInvalidFd)
 175     return false;
 176   uptr read_len = 0;
 177   while (read_len < max_len) {
 178     if (read_len >= buff->size())
 179       buff->resize(Min(Max(PageSize, read_len * 2), max_len));
 180     CHECK_LT(read_len, buff->size());
 181     CHECK_LE(buff->size(), max_len);
 182     uptr just_read;
 183     if (!ReadFromFile(fd, buff->data() + read_len, buff->size() - read_len,
 184                       &just_read, errno_p)) {
 185       CloseFile(fd);
 186       return false;
 187     }
 188     read_len += just_read;
 189     if (!just_read)
 190       break;
 191   }
 192   CloseFile(fd);
 193   buff->resize(read_len);
 194   return true;
 195 }
 196
 197 static const char kPathSeparator = SANITIZER_WINDOWS ? ';' : ':';
 198
 199 char *FindPathToBinary(const char *name) {
 200   if (FileExists(name)) {
 201     return internal_strdup(name);
 202   }
 203
 204   const char *path = GetEnv("PATH");
 205   if (!path)
 206     return nullptr;
 207   uptr name_len = internal_strlen(name);
 208   InternalMmapVector<char> buffer(kMaxPathLength);
 209   const char *beg = path;
 210   while (true) {
 211     const char *end = internal_strchrnul(beg, kPathSeparator);
 212     uptr prefix_len = end - beg;
 213     if (prefix_len + name_len + 2 <= kMaxPathLength) {
 214       internal_memcpy(buffer.data(), beg, prefix_len);
 215       buffer[prefix_len] = '/';
 216       internal_memcpy(&buffer[prefix_len + 1], name, name_len);
 217       buffer[prefix_len + 1 + name_len] = '\0';
 218       if (FileExists(buffer.data()))
 219         return internal_strdup(buffer.data());
 220     }
 221     if (*end == '\0') break;
 222     beg = end + 1;
 223   }
 224   return nullptr;
 225 }
 226
 227 } // namespace __sanitizer
 228
 229 using namespace __sanitizer;
 230
 231 extern "C" {
 232 void __sanitizer_set_report_path(const char *path) {
 233   report_file.SetReportPath(path);
 234 }
 235
 236 void __sanitizer_set_report_fd(void *fd) {
 237   report_file.fd = (fd_t)reinterpret_cast<uptr>(fd);
 238   report_file.fd_pid = internal_getpid();
 239 }
 240
 241 const char *__sanitizer_get_report_path() {
 242   return report_file.GetReportPath();
 243 }
 244 } // extern "C"
 245
 246 #endif  // !SANITIZER_FUCHSIA