src/os/posix/vm/os_posix.hpp

rev 12741 : 8173848: realpath is unsafe
Summary: Fix occurrences of realpath in hotspot to use safe POSIX.1-2008 form.
Reviewed-by: dsamersoff, dholmes, clanger

*** 1,7 ****
  /*
!  * Copyright (c) 1999, 2016, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
--- 1,7 ----
  /*
!  * Copyright (c) 1999, 2017, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
*** 94,103 ****
--- 94,110 ----
  
    // Helper function; describes pthread attributes as short string. String is written
    // to buf with len buflen; buf is returned.
    static char* describe_pthread_attr(char* buf, size_t buflen, const pthread_attr_t* attr);
  
+   // A safe implementation of realpath which will not cause a buffer overflow if the resolved path
+   //   is longer than PATH_MAX.
+   // On success, returns 'outbuf', which now contains the path.
+   // On error, it will return NULL and set errno. The content of 'outbuf' is undefined.
+   // On truncation error ('outbuf' too small), it will return NULL and set errno to ENAMETOOLONG.
+   static char* realpath(const char* filename, char* outbuf, size_t outbuflen);
+ 
  };
  
  /*
   * Crash protection for the watcher thread. Wrap the callback
   * with a sigsetjmp and in case of a SIGSEGV/SIGBUS we siglongjmp