From owner-freebsd-current  Fri Apr 17 14:12:46 1998
Return-Path: <owner-freebsd-current@FreeBSD.ORG>
Received: (from majordom@localhost)
          by hub.freebsd.org (8.8.8/8.8.8) id OAA28510
          for freebsd-current-outgoing; Fri, 17 Apr 1998 14:12:46 -0700 (PDT)
          (envelope-from owner-freebsd-current@FreeBSD.ORG)
Received: from ifi.uio.no (0@ifi.uio.no [129.240.64.2])
          by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id VAA28504
          for <current@freebsd.org>; Fri, 17 Apr 1998 21:12:40 GMT
          (envelope-from dag-erli@ifi.uio.no)
Received: from hrotti.ifi.uio.no (2602@hrotti.ifi.uio.no [129.240.64.15])
	by ifi.uio.no (8.8.8/8.8.7/ifi0.2) with ESMTP id XAA29081
	for <current@freebsd.org>; Fri, 17 Apr 1998 23:12:35 +0200 (MET DST)
Received: (from dag-erli@localhost) by hrotti.ifi.uio.no ; Fri, 17 Apr 1998 23:12:34 +0200 (MET DST)
Mime-Version: 1.0
To: current@FreeBSD.ORG
Subject: kern/6184
Organization: Gutteklubben Terrasse / KRST / PUMS / YASMW
X-url: http://www.stud.ifi.uio.no/~dag-erli/
X-Stop-Spam: http://www.cauce.org
From: dag-erli@ifi.uio.no (Dag-Erling Coidan =?iso-8859-1?Q?Sm=F8rgrav?= )
Date: 17 Apr 1998 23:12:34 +0200
Message-ID: <xzp7m4ob1a5.fsf@hrotti.ifi.uio.no>
Lines: 65
X-Mailer: Gnus v5.5/Emacs 19.34
Sender: owner-freebsd-current@FreeBSD.ORG
Precedence: bulk
X-Loop: FreeBSD.ORG

I have a patch which I hope fixes kern/6184 (lseek allows seeks to
negative offsets), but I don't want to commit it without having
someone look at it first:

Index: src/sys/kern/vfs_syscalls.c
===================================================================
RCS file: /home/ncvs/src/sys/kern/vfs_syscalls.c,v
retrieving revision 1.97
diff -u -r1.97 vfs_syscalls.c
--- vfs_syscalls.c      1998/04/08 18:31:57     1.97
+++ vfs_syscalls.c      1998/04/17 21:03:13
@@ -1324,6 +1324,7 @@
        register struct filedesc *fdp = p->p_fd;
        register struct file *fp;
        struct vattr vattr;
+       off_t ofs;
        int error;

        if ((u_int)SCARG(uap, fd) >= fdp->fd_nfiles ||
@@ -1333,21 +1334,22 @@
                return (ESPIPE);
        switch (SCARG(uap, whence)) {
        case L_INCR:
-               fp->f_offset += SCARG(uap, offset);
+               ofs = fp->f_offset + SCARG(uap, offset);
                break;
        case L_XTND:
                error=VOP_GETATTR((struct vnode *)fp->f_data, &vattr, cred, p);
                if (error)
                        return (error);
-               fp->f_offset = SCARG(uap, offset) + vattr.va_size;
+               ofs = SCARG(uap, offset) + vattr.va_size;
                break;
        case L_SET:
-               fp->f_offset = SCARG(uap, offset);
+               ofs = SCARG(uap, offset);
                break;
        default:
                return (EINVAL);
        }
-       *(off_t *)(p->p_retval) = fp->f_offset;
+       if (ofs < 0) return (EINVAL);
+       *(off_t *)(p->p_retval) = fp->f_offset = ofs;
        return (0);
 }

Index: src/lib/libc/sys/lseek.2
===================================================================
RCS file: /home/ncvs/src/lib/libc/sys/lseek.2,v
retrieving revision 1.6
diff -u -r1.6 lseek.2
--- lseek.2     1997/02/22 15:04:01     1.6
+++ lseek.2     1998/04/17 21:05:23
@@ -120,7 +120,7 @@
 is associated with a pipe, socket, or FIFO.
 .It Bq Er EINVAL
 .Fa Whence
-is not a proper value.
+is not a proper value, or the resulting offset is negative.
 .El
 .Sh SEE ALSO
 .Xr dup 2 ,

-- 
Nobody else has a .sig like this one.

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-current" in the body of the message