[src/trunk]: src/sys/rump/librump/rumpvfs Don't try to kmem_alloc() 0 bytes. ...

[riz <riz%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/c1ea6626400e
branches:  trunk
changeset: 763615:c1ea6626400e
user:      riz <riz%NetBSD.org@localhost>
date:      Sun Mar 27 21:16:52 2011 +0000

description:
Don't try to kmem_alloc() 0 bytes.  Without this change, some trivial
kernel modules were not loadable by rump_server.

diffstat:

 sys/rump/librump/rumpvfs/rumpfs.c |  8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)

diffs (36 lines):

diff -r 3b402f96cd7f -r c1ea6626400e sys/rump/librump/rumpvfs/rumpfs.c
--- a/sys/rump/librump/rumpvfs/rumpfs.c Sun Mar 27 19:47:46 2011 +0000
+++ b/sys/rump/librump/rumpvfs/rumpfs.c Sun Mar 27 21:16:52 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rumpfs.c,v 1.93 2011/03/21 16:41:09 pooka Exp $        */
+/*     $NetBSD: rumpfs.c,v 1.94 2011/03/27 21:16:52 riz Exp $  */
 
 /*
  * Copyright (c) 2009, 2010, 2011 Antti Kantee.  All Rights Reserved.
@@ -26,7 +26,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: rumpfs.c,v 1.93 2011/03/21 16:41:09 pooka Exp $");
+__KERNEL_RCSID(0, "$NetBSD: rumpfs.c,v 1.94 2011/03/27 21:16:52 riz Exp $");
 
 #include <sys/param.h>
 #include <sys/atomic.h>
@@ -1219,6 +1219,8 @@
        int error = 0;
 
        bufsize = uio->uio_resid;
+       if (bufsize == 0)
+               return 0;
        buf = kmem_alloc(bufsize, KM_SLEEP);
        if ((n = rumpuser_pread(rn->rn_readfd, buf, bufsize,
            uio->uio_offset + rn->rn_offset, &error)) == -1)
@@ -1275,6 +1277,8 @@
        int error = 0;
 
        bufsize = uio->uio_resid;
+       if (bufsize == 0)
+               return 0;
        buf = kmem_alloc(bufsize, KM_SLEEP);
        error = uiomove(buf, bufsize, uio);
        if (error)