Testing new getpt(3) and posix_openpt(3) implementation

[Guillem Jover <guillem@debian.org>]

Hi!

I just got annoyed enough with the kFreeBSD message on the console:

  "pid %d (%s) is using legacy pty devices%s\n"

that I started digging around. This is due to applications using the
old BSD-style pseudo-terminal master device.

I've switched the eglibc getpt(3) and posix_openpt(3) to use the new
posix_openpt(2) syscall introduced in kFreeBSD 8.0. I've done this
instead of using the compatibility ‘/dev/ptmx’ device, because it
should allow us to unload the compatibility pty(4) kernel module.

I've not build or run tested the code, so if someone with an eglibc
build-tree around could test the attached patch (against the
glibc-ports tree) that would be pretty helpful, otherwise I might try
to, once I've got some spare time.

thanks,
guillem

Index: kfreebsd/getpt.c
===================================================================
--- kfreebsd/getpt.c	(revision 3428)
+++ kfreebsd/getpt.c	(working copy)
@@ -21,63 +21,27 @@
 #include <string.h>
 #include <unistd.h>
 #include <sys/ioctl.h>
+#include <sysdep.h>
 
+/* The system call does not change the controlling terminal, so we have
+ * to do it ourselves.  */
+extern int __syscall_posix_openpt (int oflag);
+libc_hidden_proto (__syscall_posix_openpt)
 
-/* Prefix for master pseudo terminal nodes.  */
-#define _PATH_PTY "/dev/pty"
+/* Prototype for function that opens BSD-style master pseudo-terminals.  */
+int __bsd_getpt (void);
 
-
-/* Letters indicating a series of pseudo terminals.  */
-#ifndef PTYNAME1
-#define PTYNAME1 "pqrs"
-#endif
-const char __libc_ptyname1[] attribute_hidden = PTYNAME1;
-
-/* Letters indicating the position within a series.  */
-#ifndef PTYNAME2
-#define PTYNAME2 "0123456789abcdefghijklmnopqrstuv";
-#endif
-const char __libc_ptyname2[] attribute_hidden = PTYNAME2;
-
-
 /* Open a master pseudo terminal and return its file descriptor.  */
 int
 __posix_openpt (int oflag)
 {
-  char buf[sizeof (_PATH_PTY) + 2];
-  const char *p, *q;
-  char *s;
-
-  s = __mempcpy (buf, _PATH_PTY, sizeof (_PATH_PTY) - 1);
-  /* s[0] and s[1] will be filled in the loop.  */
-  s[2] = '\0';
-
-  for (p = __libc_ptyname1; *p != '\0'; ++p)
+  int fd = INLINE_SYSCALL (posix_openpt, 1, oflag);
+  if (fd >= 0)
     {
-      s[0] = *p;
-
-      for (q = __libc_ptyname2; *q != '\0'; ++q)
-	{
-	  int fd;
-
-	  s[1] = *q;
-
-	  fd = __open (buf, oflag);
-	  if (fd >= 0)
-	    {
-	      if (!(oflag & O_NOCTTY))
-		__ioctl (fd, TIOCSCTTY, NULL);
-
-	      return fd;
-	    }
-
-	  if (errno == ENOENT)
-	    return -1;
-	}
+      if (!(oflag & O_NOCTTY))
+        __ioctl (fd, TIOCSCTTY, NULL);
     }
-
-  __set_errno (ENOENT);
-  return -1;
+  return fd;
 }
 
 weak_alias (__posix_openpt, posix_openpt)
@@ -86,7 +50,25 @@
 int
 __getpt (void)
 {
-  return __posix_openpt (O_RDWR);
+  int fd = __posix_openpt (O_RDWR);
+  if (fd == -1)
+    {
+      fd = __bsd_getpt ();
+      if (fd >= 0)
+        {
+          if (!(oflag & O_NOCTTY))
+            __ioctl (fd, TIOCSCTTY, NULL);
+        }
+    }
+  return fd;
 }
 
-weak_alias (__getpt, getpt)
+
+/* Letters indicating a series of pseudo terminals.  */
+#define PTYNAME1 "pqrs";
+/* Letters indicating the position within a series.  */
+#define PTYNAME2 "0123456789abcdefghijklmnopqrstuv";
+
+#define __getpt __bsd_getpt
+#define HAVE_POSIX_OPENPT
+#include <sysdeps/unix/bsd/getpt.c>
Index: kfreebsd/syscalls.list
===================================================================
--- kfreebsd/syscalls.list	(revision 3428)
+++ kfreebsd/syscalls.list	(working copy)
@@ -98,6 +98,7 @@
 ntp_adjtime		-	ntp_adjtime		i:p		ntp_adjtime
 obreak			-	obreak			i:a		__syscall_obreak
 sys_open		-	open			i:siv		__syscall_open
+posix_openpt		getpt	posix_openpt		i:i		__syscall_posix_openpt
 poll			-	poll			Ci:pii		__poll poll
 sys_pread		-	pread			i:ibni		__syscall_pread
 sys_freebsd6_pread	-	freebsd6_pread		i:ibnii		__syscall_freebsd6_pread
Index: kfreebsd/Versions
===================================================================
--- kfreebsd/Versions	(revision 3428)
+++ kfreebsd/Versions	(working copy)
@@ -112,6 +112,7 @@
     # misc fixes for FreeBSD:
     __syscall_freebsd6_lseek; __syscall_freebsd6_pread; __syscall_freebsd6_pwrite;
     __syscall_lseek; __syscall_pread; __syscall_pwrite;
+    __syscall_posix_openpt;
     __syscall_connect; __syscall_sendto;
     __syscall_cpuset_getaffinity ; __syscall_cpuset_setaffinity;
      # global variable used in brk()