Re: [PATCH] simplify ulimit implementation

[Pino Toscano <toscano dot pino at tiscali dot it>]

Hi,

Alle lunedì 19 novembre 2012, Roland McGrath ha scritto:
> I don't think losing __UL_GETMAXBRK is really a problem.  The reason
> for removing it was not specific to Linux, just to the
> implementation being in a shared library.  It could be implemented
> in a shared library, at the cost of a GOT reloc for _etext to get
> the main executable's value (or conversely, perhaps some grovelling
> in dynamic linker data structures for the shared case).  But given
> that the current implementation usable on the Hurd will yield
> utterly useless values, the case for having it at all is
> inordinately weak.

OK.

Attached there are the two patches of the ulimit reorganization, as you 
suggested in a previous email:
1) move the linux implementation as posix (including limits.h)
2) remove the bsd implementation

Thanks,
-- 
Pino Toscano

ulimit: move linux implementation as posix

The linux implementation of ulimit works correctly and has nothing specific
to Linux, so move it as general posix implementation.

2013-01-15  Pino Toscano  <toscano.pino@tiscali.it>

	* sysdeps/unix/sysv/linux/ulimit.c: Moved to ...
	* sysdeps/posix/ulimit.c: ... this.
	Include <limits.h>.

--- /dev/null
+++ b/sysdeps/posix/ulimit.c
@@ -0,0 +1,90 @@
+/* Copyright (C) 1991-2013 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
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <stdarg.h>
+#include <sysdep.h>
+#include <ulimit.h>
+#include <unistd.h>
+#include <limits.h>
+#include <sys/resource.h>
+
+/* Function depends on CMD:
+   1 = Return the limit on the size of a file, in units of 512 bytes.
+   2 = Set the limit on the size of a file to NEWLIMIT.  Only the
+       super-user can increase the limit.
+   4 = Return the maximum number of files that the calling process
+       can open.
+   Returns -1 on errors.  */
+long int
+__ulimit (int cmd, ...)
+{
+  struct rlimit limit;
+  va_list va;
+  long int result = -1;
+
+  va_start (va, cmd);
+
+  switch (cmd)
+    {
+    case UL_GETFSIZE:
+      /* Get limit on file size.  */
+      if (__getrlimit (RLIMIT_FSIZE, &limit) == 0)
+	/* Convert from bytes to 512 byte units.  */
+	result =  (limit.rlim_cur == RLIM_INFINITY
+		   ? LONG_MAX : limit.rlim_cur / 512);
+      break;
+
+    case UL_SETFSIZE:
+      /* Set limit on file size.  */
+      {
+	long int newlimit = va_arg (va, long int);
+	long int newlen;
+
+	if ((rlim_t) newlimit > RLIM_INFINITY / 512)
+	  {
+	    limit.rlim_cur = RLIM_INFINITY;
+	    limit.rlim_max = RLIM_INFINITY;
+	    newlen = LONG_MAX;
+	  }
+	else
+	  {
+	    limit.rlim_cur = newlimit * 512;
+	    limit.rlim_max = newlimit * 512;
+	    newlen = newlimit;
+	  }
+
+	result = __setrlimit (RLIMIT_FSIZE, &limit);
+	if (result != -1)
+	  result = newlen;
+      }
+      break;
+
+    case __UL_GETOPENMAX:
+      result = __sysconf (_SC_OPEN_MAX);
+      break;
+
+    default:
+      __set_errno (EINVAL);
+    }
+
+  va_end (va);
+
+  return result;
+}
+
+weak_alias (__ulimit, ulimit);
--- a/sysdeps/unix/sysv/linux/ulimit.c
+++ /dev/null
@@ -1,91 +0,0 @@
-/* Copyright (C) 1991-2013 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
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <http://www.gnu.org/licenses/>.  */
-
-#include <errno.h>
-#include <stdarg.h>
-#include <sysdep.h>
-#include <ulimit.h>
-#include <unistd.h>
-#include <sys/resource.h>
-
-/* Function depends on CMD:
-   1 = Return the limit on the size of a file, in units of 512 bytes.
-   2 = Set the limit on the size of a file to NEWLIMIT.  Only the
-       super-user can increase the limit.
-   3 = illegal due to shared libraries; normally is
-       (Return the maximum possible address of the data segment.)
-   4 = Return the maximum number of files that the calling process
-       can open.
-   Returns -1 on errors.  */
-long int
-__ulimit (int cmd, ...)
-{
-  struct rlimit limit;
-  va_list va;
-  long int result = -1;
-
-  va_start (va, cmd);
-
-  switch (cmd)
-    {
-    case UL_GETFSIZE:
-      /* Get limit on file size.  */
-      if (__getrlimit (RLIMIT_FSIZE, &limit) == 0)
-	/* Convert from bytes to 512 byte units.  */
-	result =  (limit.rlim_cur == RLIM_INFINITY
-		   ? LONG_MAX : limit.rlim_cur / 512);
-      break;
-
-    case UL_SETFSIZE:
-      /* Set limit on file size.  */
-      {
-	long int newlimit = va_arg (va, long int);
-	long int newlen;
-
-	if ((rlim_t) newlimit > RLIM_INFINITY / 512)
-	  {
-	    limit.rlim_cur = RLIM_INFINITY;
-	    limit.rlim_max = RLIM_INFINITY;
-	    newlen = LONG_MAX;
-	  }
-	else
-	  {
-	    limit.rlim_cur = newlimit * 512;
-	    limit.rlim_max = newlimit * 512;
-	    newlen = newlimit;
-	  }
-
-	result = __setrlimit (RLIMIT_FSIZE, &limit);
-	if (result != -1)
-	  result = newlen;
-      }
-      break;
-
-    case __UL_GETOPENMAX:
-      result = __sysconf (_SC_OPEN_MAX);
-      break;
-
-    default:
-      __set_errno (EINVAL);
-    }
-
-  va_end (va);
-
-  return result;
-}
-
-weak_alias (__ulimit, ulimit);

ulimit: remove buggy bsd implementation

The bsd implementation of ulimit produces wrong return values, so remove it
in favour of the posix implementation.

The only regression for non-Linux implementations using bsd sysdeps and not
providing an own ulimit is that the __UL_GETMAXBRK case (which is non-standard)
is left unimplemented (giving EINVAL).

2013-01-15  Pino Toscano  <toscano.pino@tiscali.it>

	* sysdeps/unix/bsd/ulimit.c: Remove file.

--- a/sysdeps/unix/bsd/ulimit.c
+++ /dev/null
@@ -1,91 +0,0 @@
-/* Copyright (C) 1991-2013 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
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <http://www.gnu.org/licenses/>.  */
-
-#include <errno.h>
-#include <stdarg.h>
-#include <sysdep.h>
-#include <ulimit.h>
-#include <unistd.h>
-#include <sys/resource.h>
-
-
-extern int _etext;
-
-/* Function depends on CMD:
-   1 = Return the limit on the size of a file, in units of 512 bytes.
-   2 = Set the limit on the size of a file to NEWLIMIT.  Only the
-       super-user can increase the limit.
-   3 = Return the maximum possible address of the data segment.
-   4 = Return the maximum number of files that the calling process
-       can open.
-   Returns -1 on errors.  */
-long int
-ulimit (int cmd, ...)
-{
-  struct rlimit limit;
-  va_list va;
-  long int result = -1;
-
-  va_start (va, cmd);
-
-  switch (cmd)
-    {
-    case UL_GETFSIZE:
-      /* Get limit on file size.  */
-      if (getrlimit (RLIMIT_FSIZE, &limit) == 0)
-	/* Convert from bytes to 512 byte units.  */
-	result = limit.rlim_cur / 512;
-      break;
-
-    case UL_SETFSIZE:
-      /* Set limit on file size.  */
-      {
-	long int newlimit = va_arg (va, long int);
-
-	if ((rlim_t) newlimit > RLIM_INFINITY / 512)
-	  {
-	    limit.rlim_cur = RLIM_INFINITY;
-	    limit.rlim_max = RLIM_INFINITY;
-	  }
-	else
-	  {
-	    limit.rlim_cur = newlimit * 512;
-	    limit.rlim_max = newlimit * 512;
-	  }
-
-	result = setrlimit (RLIMIT_FSIZE, &limit);
-      }
-      break;
-
-    case __UL_GETMAXBRK:
-      /* Get maximum address for `brk'.  */
-      if (getrlimit (RLIMIT_DATA, &limit) == 0)
-	result = ((long int) &_etext) + limit.rlim_cur;
-      break;
-
-    case __UL_GETOPENMAX:
-      result = sysconf (_SC_OPEN_MAX);
-      break;
-
-    default:
-      __set_errno (EINVAL);
-    }
-
-  va_end (va);
-
-  return result;
-}

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