Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752200Ab1COCax (ORCPT ); Mon, 14 Mar 2011 22:30:53 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:63312 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751169Ab1COCav (ORCPT ); Mon, 14 Mar 2011 22:30:51 -0400 Message-ID: <4D7ECF91.2030308@cn.fujitsu.com> Date: Tue, 15 Mar 2011 10:31:45 +0800 From: Mi Jinlong User-Agent: Thunderbird 2.0.0.9 (Windows/20071031) MIME-Version: 1.0 To: "J. Bruce Fields" CC: roel , Neil Brown , linux-nfs@vger.kernel.org, Andrew Morton , LKML Subject: Re: [PATCH] nfsd: wrong index used in inner loop References: <4D76A06A.4090405@gmail.com> <20110309004955.GD15814@fieldses.org> <4D79A183.8090306@cn.fujitsu.com> <20110314222229.GJ25442@fieldses.org> In-Reply-To: <20110314222229.GJ25442@fieldses.org> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2011-03-15 10:29:31, Serialize by Router on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2011-03-15 10:29:32, Serialize complete at 2011-03-15 10:29:32 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3867 Lines: 138 J. Bruce Fields: > On Fri, Mar 11, 2011 at 12:13:55PM +0800, Mi Jinlong wrote: >> >> J. Bruce Fields: >>> On Tue, Mar 08, 2011 at 10:32:26PM +0100, roel wrote: >>>> Index i was already used in the outer loop >>>> >>>> Signed-off-by: Roel Kluin >>>> --- >>>> fs/nfsd/nfs4xdr.c | 4 ++-- >>>> 1 files changed, 2 insertions(+), 2 deletions(-) >>>> >>>> Not 100% sure this one is needed but it looks suspicious. >>> Looks bad to me, thanks. >>> >>> nfsd4_decode_create_session should probably really be broken up a little >>> bit; if it wasn't so long this would have been more obvious. >>> >>> I'll see if I can slip this into 2.6.38 with a couple other last-minute >>> patches.... Otherwise, it'll be in 2.6.39. >>> >>> --b. >>> >>>> diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c >>>> index 1275b86..615f0a9 100644 >>>> --- a/fs/nfsd/nfs4xdr.c >>>> +++ b/fs/nfsd/nfs4xdr.c >>>> @@ -1142,7 +1142,7 @@ nfsd4_decode_create_session(struct nfsd4_compoundargs *argp, >>>> >>>> u32 dummy; >>>> char *machine_name; >>>> - int i; >>>> + int i, j; >>>> int nr_secflavs; >>>> >>>> READ_BUF(16); >>>> @@ -1215,7 +1215,7 @@ nfsd4_decode_create_session(struct nfsd4_compoundargs *argp, >>>> READ_BUF(4); >>>> READ32(dummy); >>>> READ_BUF(dummy * 4); >>>> - for (i = 0; i < dummy; ++i) >>>> + for (j = 0; j < dummy; ++j) >>>> READ32(dummy); >> We must not use dummy for index here. >> After the first index, READ32(dummy) will change dummy!!!! > > Actually, wait, this is kind of silly. I don't see why we couldn't just > skip the loop and do > > p += dummy; > > Also, your new test is still failing with a BAD_XDR error. Well, maybe > the test should fail--we don't really implement this yet anyway--but it > should at least be getting past the xdr decoding. So something else is > still wrong. How did you modify it?? When testing it, I modify as - for (j = 0; j < dummy; ++j) - READ32(dummy); + p += dummy; or - for (j = 0; j < dummy; ++j) - READ32(dummy); Test case CSESS16 and CSESS16a are PASS, I can't get BAD_XDR error as you said. -- thanks, Mi Jinlong > > --b. > >> The following patch fix this problem. >> >> -- >> thanks, >> Mi Jinlong >> ============================================================ >> >> We must not use dummy for index. >> After the first index, READ32(dummy) will change dummy!!!! >> >> Signed-off-by: Mi Jinlong >> --- >> fs/nfsd/nfs4xdr.c | 4 ++-- >> 1 files changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c >> index 615f0a9..8dd70d0 100644 >> --- a/fs/nfsd/nfs4xdr.c >> +++ b/fs/nfsd/nfs4xdr.c >> @@ -1140,7 +1140,7 @@ nfsd4_decode_create_session(struct nfsd4_compoundargs *argp, >> { >> DECODE_HEAD; >> >> - u32 dummy; >> + u32 dummy, tmp; >> char *machine_name; >> int i, j; >> int nr_secflavs; >> @@ -1216,7 +1216,7 @@ nfsd4_decode_create_session(struct nfsd4_compoundargs *argp, >> READ32(dummy); >> READ_BUF(dummy * 4); >> for (j = 0; j < dummy; ++j) >> - READ32(dummy); >> + READ32(tmp); >> break; >> case RPC_AUTH_GSS: >> dprintk("RPC_AUTH_GSS callback secflavor " >> -- >> 1.7.4.1 >> >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- ---- thanks Mi Jinlong -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/