Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:56410 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726586AbeGKQK2 (ORCPT ); Wed, 11 Jul 2018 12:10:28 -0400 Subject: Re: [PATCH V4] xdrstdio_create buffers do not output encoded values on ppc To: Libtirpc-devel Mailing List , Trond Myklebust Cc: Linux NFS Mailing list References: <20180711152521.8238-1-steved@redhat.com> From: Steve Dickson Message-ID: Date: Wed, 11 Jul 2018 12:05:26 -0400 MIME-Version: 1.0 In-Reply-To: <20180711152521.8238-1-steved@redhat.com> Content-Type: text/plain; charset=utf-8 Sender: linux-nfs-owner@vger.kernel.org List-ID: Hey Trond, On 07/11/2018 11:25 AM, Steve Dickson wrote: > The cause is that the xdr_putlong uses a long to store the > converted value, then passes it to fwrite as a byte buffer. > Only the first 4 bytes are written, which is okay for a LE > system after byteswapping, but writes all zeroes on BE systems. > > Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1261738 > > Reviewed-by: Chuck Lever > Signed-off-by: Steve Dickson > --- > v4: Use UINT32_MAX instead of INT32_MAX in boundary check. Talking with some old crusty types ;-) they pointed out that all these routines use a signed arguments and always have... So again why is using an unsigned max the right thing to do? steved. > > v3: Reworked the bounds checking > > v2: Added bounds checking > Changed from unsigned to signed > > src/xdr_stdio.c | 15 ++++++++++++--- > 1 file changed, 12 insertions(+), 3 deletions(-) > > diff --git a/src/xdr_stdio.c b/src/xdr_stdio.c > index 4410262..846c7bf 100644 > --- a/src/xdr_stdio.c > +++ b/src/xdr_stdio.c > @@ -38,6 +38,7 @@ > */ > > #include > +#include > > #include > #include > @@ -103,10 +104,12 @@ xdrstdio_getlong(xdrs, lp) > XDR *xdrs; > long *lp; > { > + int32_t mycopy; > > - if (fread(lp, sizeof(int32_t), 1, (FILE *)xdrs->x_private) != 1) > + if (fread(&mycopy, sizeof(int32_t), 1, (FILE *)xdrs->x_private) != 1) > return (FALSE); > - *lp = (long)ntohl((u_int32_t)*lp); > + > + *lp = (long)ntohl(mycopy); > return (TRUE); > } > > @@ -115,8 +118,14 @@ xdrstdio_putlong(xdrs, lp) > XDR *xdrs; > const long *lp; > { > - long mycopy = (long)htonl((u_int32_t)*lp); > + int32_t mycopy; > + > +#if defined(_LP64) > + if ((*lp > UINT32_MAX) || (*lp < INT32_MIN)) > + return (FALSE); > +#endif > > + mycopy = (int32_t)htonl((int32_t)*lp); > if (fwrite(&mycopy, sizeof(int32_t), 1, (FILE *)xdrs->x_private) != 1) > return (FALSE); > return (TRUE); >