From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 1 Jul 2020 13:53:24 +0000 From: Luis Chamberlain Subject: Re: linux-next: umh: fix processed error when UMH_WAIT_PROC is used seems to break linux bridge on s390x (bisected) Message-ID: <20200701135324.GS4332@42.do-not-panic.com> References: <9e767819-9bbe-2181-521e-4d8ca28ca4f7@de.ibm.com> <20200624160953.GH4332@42.do-not-panic.com> <4e27098e-ac8d-98f0-3a9a-ea25242e24ec@de.ibm.com> <4d8fbcea-a892-3453-091f-d57c03f9aa90@de.ibm.com> <1263e370-7cee-24d8-b98c-117bf7c90a83@de.ibm.com> <20200626025410.GJ4332@42.do-not-panic.com> <20200630175704.GO13911@42.do-not-panic.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: To: Tetsuo Handa Cc: Christian Borntraeger , Christoph Hellwig , ast@kernel.org, axboe@kernel.dk, bfields@fieldses.org, bridge@lists.linux-foundation.org, chainsaw@gentoo.org, christian.brauner@ubuntu.com, chuck.lever@oracle.com, davem@davemloft.net, dhowells@redhat.com, gregkh@linuxfoundation.org, jarkko.sakkinen@linux.intel.com, jmorris@namei.org, josh@joshtriplett.org, keescook@chromium.org, keyrings@vger.kernel.org, kuba@kernel.org, lars.ellenberg@linbit.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-security-module@vger.kernel.org, nikolay@cumulusnetworks.com, philipp.reisner@linbit.com, ravenexp@gmail.com, roopa@cumulusnetworks.com, serge@hallyn.com, slyfox@gentoo.org, viro@zeniv.linux.org.uk, yangtiezhu@loongson.cn, netdev@vger.kernel.org, markward@linux.ibm.com, linux-s390 On Wed, Jul 01, 2020 at 10:24:29PM +0900, Tetsuo Handa wrote: > On 2020/07/01 19:08, Christian Borntraeger wrote: > > > > > > On 30.06.20 19:57, Luis Chamberlain wrote: > >> On Fri, Jun 26, 2020 at 02:54:10AM +0000, Luis Chamberlain wrote: > >>> On Wed, Jun 24, 2020 at 08:37:55PM +0200, Christian Borntraeger wrote: > >>>> > >>>> > >>>> On 24.06.20 20:32, Christian Borntraeger wrote: > >>>> [...]> > >>>>> So the translations look correct. But your change is actually a sematic change > >>>>> if(ret) will only trigger if there is an error > >>>>> if (KWIFEXITED(ret)) will always trigger when the process ends. So we will always overwrite -ECHILD > >>>>> and we did not do it before. > >>>>> > >>>> > >>>> So the right fix is > >>>> > >>>> diff --git a/kernel/umh.c b/kernel/umh.c > >>>> index f81e8698e36e..a3a3196e84d1 100644 > >>>> --- a/kernel/umh.c > >>>> +++ b/kernel/umh.c > >>>> @@ -154,7 +154,7 @@ static void call_usermodehelper_exec_sync(struct subprocess_info *sub_info) > >>>> * the real error code is already in sub_info->retval or > >>>> * sub_info->retval is 0 anyway, so don't mess with it then. > >>>> */ > >>>> - if (KWIFEXITED(ret)) > >>>> + if (KWEXITSTATUS(ret)) > >>>> sub_info->retval = KWEXITSTATUS(ret); > > Well, it is not br_stp_call_user() but br_stp_start() which is expecting > to set sub_info->retval for both KWIFEXITED() case and KWIFSIGNALED() case. > That is, sub_info->retval needs to carry raw value (i.e. without "umh: fix > processed error when UMH_WAIT_PROC is used" will be the correct behavior). br_stp_start() doesn't check for the raw value, it just checks for err or !err. So the patch, "umh: fix processed error when UMH_WAIT_PROC is used" propagates the correct error now. Christian, can you try removing the binary temporarily and seeing if you get your bridge working? Luis