ulimit (2, -1)

[Andreas Jaeger]

The following program:

#include <ulimit.h>
#include <stdio.h>

int
main (void)
{
  long int res =  ulimit (2, -1);

  printf ("Res: %ld, errno: %m\n", res);
  
  return 0;
}

Returns:
$ ./a.out 
Res: 0, errno: Success

which is wrong, setting the limit to -1 should IMO give an error.  The
problem is that in ulimit.c we tread the second argument as long int
and assign it to:
	limit.rlim_cur = newlimit * 512;
where rlim_cur is of type rlim_t which is unsigned long.  Shouldn't we
check for negative values and set errno to EINVAL in this case?  I'm
appending a patch.

Can somebody please double check this with the standards?

If the patch is ok, I'll fix also the other ulimit implementations in
glibc.  Ok to commit?

Andreas

2001-09-22  Andreas Jaeger  <aj@suse.de>

	* sysdeps/unix/sysv/linux/ulimit.c (__ulimit): Return an error for
	negative values on UL_SETFSIZE.

============================================================
Index: sysdeps/unix/sysv/linux/ulimit.c
--- sysdeps/unix/sysv/linux/ulimit.c	2001/07/06 04:56:13	1.8
+++ sysdeps/unix/sysv/linux/ulimit.c	2001/09/22 13:34:53
@@ -1,4 +1,4 @@
-/* Copyright (C) 1991,92,94,95,96,97,98,2000 Free Software Foundation, Inc.
+/* Copyright (C) 1991,92,94,95,96,97,98,2000,2001 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -55,10 +55,15 @@
       {
 	long int newlimit = va_arg (va, long int);
 
-	limit.rlim_cur = newlimit * 512;
-	limit.rlim_max = newlimit * 512;
-
-	result = __setrlimit (RLIMIT_FSIZE, &limit);
+	if (newlimit >= 0)
+	  {
+	    limit.rlim_cur = newlimit * 512;
+	    limit.rlim_max = newlimit * 512;
+
+	    result = __setrlimit (RLIMIT_FSIZE, &limit);
+	  }
+	else
+	  __set_errno (EINVAL);
       }
       break;
 

-- 
 Andreas Jaeger
  SuSE Labs aj@suse.de
   private aj@arthur.inka.de
    http://www.suse.de/~aj