src/os/linux/vm/os_linux.cpp

*** 5986,6002 ****
  }
  
  // Get the default path to the core file
  // Returns the length of the string
  int os::get_core_path(char* buffer, size_t bufferSize) {
!   const char* p = get_current_directory(buffer, bufferSize);
  
    if (p == NULL) {
      assert(p != NULL, "failed to get current directory");
      return 0;
    }
  
    return strlen(buffer);
  }
  
  /////////////// Unit tests ///////////////
  
--- 5986,6059 ----
  }
  
  // Get the default path to the core file
  // Returns the length of the string
  int os::get_core_path(char* buffer, size_t bufferSize) {
!   /*
!    * Max length of /proc/sys/kernel/core_pattern is 128 characters.
!    * See https://www.kernel.org/doc/Documentation/sysctl/kernel.txt
!    */
!   const int core_pattern_len = 129;
!   char core_pattern[core_pattern_len] = {0};
  
+   int core_pattern_file = ::open("/proc/sys/kernel/core_pattern", O_RDONLY);
+   if (core_pattern_file != -1) {
+     ssize_t ret = ::read(core_pattern_file, core_pattern, core_pattern_len);
+     ::close(core_pattern_file);
+ 
+     if (ret > 0) {
+       char *last_char = core_pattern + strlen(core_pattern) - 1;
+ 
+       if (*last_char == '\n') {
+         *last_char = '\0';
+       }
+     }
+   }
+ 
+   if (strlen(core_pattern) == 0) {
+     return 0;
+   }
+ 
+   char *pid_pos = strstr(core_pattern, "%p");
+   size_t written;
+ 
+   if (core_pattern[0] == '/') {
+     written = jio_snprintf(buffer, bufferSize, core_pattern);
+   } else {
+     char cwd[PATH_MAX];
+ 
+     const char* p = get_current_directory(cwd, PATH_MAX);
      if (p == NULL) {
        assert(p != NULL, "failed to get current directory");
        return 0;
      }
  
+     if (core_pattern[0] == '|') {
+       written = jio_snprintf(buffer, bufferSize,
+                         "\"%s\" (or dumping to %s/core.%d)",
+                                      &core_pattern[1], p, current_process_id());
+     } else {
+       written = jio_snprintf(buffer, bufferSize, "%s/%s", p, core_pattern);
+     }
+   }
+ 
+   if ((written >= 0) && (written < bufferSize)
+             && (pid_pos == NULL) && (core_pattern[0] != '|')) {
+     int core_uses_pid_file = ::open("/proc/sys/kernel/core_uses_pid", O_RDONLY);
+ 
+     if (core_uses_pid_file != -1) {
+       char core_uses_pid = 0;
+       ssize_t ret = ::read(core_uses_pid_file, &core_uses_pid, 1);
+       ::close(core_uses_pid_file);
+ 
+       if (core_uses_pid == '1'){
+         jio_snprintf(buffer + written, bufferSize - written,
+                                           ".%d", current_process_id());
+       }
+     }
+   }
+ 
    return strlen(buffer);
  }
  
  /////////////// Unit tests ///////////////