Re: libc/unix, reentrant syscalls?

[Jeff Johnston <jjohnstn at redhat dot com>]

Hi Pedro,

  A little late in answering this, but yes, you are correct.  The only 
usage of the non-reentrant _ syscall names should be either in the _r 
version-code or else in system-specific code that knows there is no 
reentrant version.

  A patch has been checked in.

-- Jeff J.

pedro_alves@portugalmail.pt wrote:
> Hi all again,
>
> In the libc/unix dir, all the syscalls are made with the underscored version.
> If newlib is compiled with with reentrancy support, these won't exist.
> Shouldn't they be switched over to the not-underscored ones?
>
> Look at the following (not complete) patch for example:
>
> Index: getpass.c
> ===================================================================
> RCS file: /cvs/src/src/newlib/libc/unix/getpass.c,v
> retrieving revision 1.3
> diff -u -r1.3 getpass.c
> --- getpass.c	9 Dec 2000 01:20:32 -0000	1.3
> +++ getpass.c	27 Oct 2005 23:00:48 -0000
> @@ -90,7 +90,9 @@
>      if (p < buf + _PASSWORD_LEN)
>        *p++ = ch;
>    *p = '\0';
> -  (void) _write (fileno (outfp), "\n", 1);
> +/* pedro: what about the reentrant version ? 
> +  (void) _write (fileno (outfp), "\n", 1); */
> +  (void) write (fileno (outfp), "\n", 1);
>    if (echo)
>      {
>        term.c_lflag |= ECHO;
> Index: getut.c
> ===================================================================
> RCS file: /cvs/src/src/newlib/libc/unix/getut.c,v
> retrieving revision 1.3
> diff -u -r1.3 getut.c
> --- getut.c	24 Aug 2000 18:51:09 -0000	1.3
> +++ getut.c	27 Oct 2005 23:00:48 -0000
> @@ -11,20 +11,25 @@
>  
>  static struct utmp utmp_data;
>  
> +/* pedro: removed underscore in syscalls to enable the use of the reentrant
> versions */
> +
>  void
>  setutent ()
>  {
>    if (utmp_fd == -2)
>      {
> -      utmp_fd = _open (utmp_file, O_RDONLY);
> +//      utmp_fd = _open (utmp_file, O_RDONLY);
> +      utmp_fd = open (utmp_file, O_RDONLY);
>      }
> -  _lseek (utmp_fd, 0, SEEK_SET);
> +//  _lseek (utmp_fd, 0, SEEK_SET);
> +  lseek (utmp_fd, 0, SEEK_SET);
>  }
>  
>  void
>  endutent ()
>  {
> -  _close (utmp_fd);
> +//  _close (utmp_fd);
> +  close (utmp_fd);
>    utmp_fd = -2;
>  }
>  
> @@ -39,7 +44,8 @@
>  {
>    if (utmp_fd == -2)
>      setutent ();
> -  if (_read (utmp_fd, &utmp_data, sizeof (utmp_data)) < sizeof (utmp_data))
> +//  if (_read (utmp_fd, &utmp_data, sizeof (utmp_data)) < sizeof (utmp_data))
> +  if (read (utmp_fd, &utmp_data, sizeof (utmp_data)) < sizeof (utmp_data))
>      return 0;
>    return &utmp_data;
>  }
> @@ -47,7 +53,8 @@
>  struct utmp *
>  getutid (struct utmp *id)
>  {
> -  while (_read (utmp_fd, &utmp_data, sizeof (utmp_data)) == sizeof (utmp_data))
> +//  while (_read (utmp_fd, &utmp_data, sizeof (utmp_data)) == sizeof (utmp_data))
> +  while (read (utmp_fd, &utmp_data, sizeof (utmp_data)) == sizeof (utmp_data))
>      {
>        switch (id->ut_type)
>  	{
> @@ -73,7 +80,8 @@
>  struct utmp *
>  getutline (struct utmp *line)
>  {
> -  while (_read (utmp_fd, &utmp_data, sizeof (utmp_data)) == sizeof (utmp_data))
> +//  while (_read (utmp_fd, &utmp_data, sizeof (utmp_data)) == sizeof (utmp_data))
> +  while (read (utmp_fd, &utmp_data, sizeof (utmp_data)) == sizeof (utmp_data))
>      {
>        if ((utmp_data.ut_type == LOGIN_PROCESS ||
>  	   utmp_data.ut_type == USER_PROCESS) &&
> Index: ttyname.c
> ===================================================================
> RCS file: /cvs/src/src/newlib/libc/unix/ttyname.c,v
> retrieving revision 1.3
> diff -u -r1.3 ttyname.c
> --- ttyname.c	7 Jul 2005 17:29:13 -0000	1.3
> +++ ttyname.c	27 Oct 2005 23:00:48 -0000
> @@ -62,7 +62,8 @@
>      return NULL;
>  
>    /* Must be a character device. */
> -  if (_fstat (fd, &sb) || !S_ISCHR (sb.st_mode))
> +/* pedro: if (_fstat (fd, &sb) || !S_ISCHR (sb.st_mode)) */
> +  if (fstat (fd, &sb) || !S_ISCHR (sb.st_mode))
>      return NULL;
>  
>    if ((dp = _opendir (_PATH_DEV)) == NULL)
>
>
>
> Cheers, 
> Pedro Alves
>
>
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