From: Alexander Aring <aahringo@redhat.com>
To: paulmck@kernel.org
Cc: Dan Carpenter <dan.carpenter@oracle.com>,
Randy Dunlap <rdunlap@infradead.org>,
kernel test robot <lkp@intel.com>,
kbuild-all@lists.01.org, linux-kernel@vger.kernel.org,
David Teigland <teigland@redhat.com>,
cluster-devel <cluster-devel@redhat.com>,
linux-sparse@vger.kernel.org, rcu@vger.kernel.org
Subject: Re: fs/dlm/midcomms.c:913:22: sparse: sparse: restricted __le32 degrades to integer
Date: Wed, 26 Jan 2022 09:39:51 -0500 [thread overview]
Message-ID: <CAK-6q+gye79SDL-zh6Uq_-oCa1gMELVi_riuqnBs-EPYfyNbow@mail.gmail.com> (raw)
In-Reply-To: <CAK-6q+j-3CWEvbFVqxd-_rc67VBZHBXPbGOo5QfGUb_KFEf_FA@mail.gmail.com>
Hi,
On Tue, Jan 25, 2022 at 5:35 PM Alexander Aring <aahringo@redhat.com> wrote:
>
> Hi,
>
> On Mon, Jan 24, 2022 at 5:14 PM Paul E. McKenney <paulmck@kernel.org> wrote:
> >
> > On Mon, Jan 24, 2022 at 04:36:55PM -0500, Alexander Aring wrote:
> > > Hi,
> > >
> > > On Mon, Jan 24, 2022 at 3:23 PM Paul E. McKenney <paulmck@kernel.org> wrote:
> > > >
> > > > On Mon, Jan 24, 2022 at 12:41:04PM -0500, Alexander Aring wrote:
> > > > > Hi,
> > > > >
> > > > > On Mon, Jan 24, 2022 at 12:36 PM Alexander Aring <aahringo@redhat.com> wrote:
> > > > > >
> > > > > > Hi,
> > > > > >
> > > > > > On Mon, Jan 24, 2022 at 12:21 PM Alexander Aring <aahringo@redhat.com> wrote:
> > > > > > >
> > > > > > > Hi,
> > > > > > >
> > > > > > > On Mon, Jan 24, 2022 at 7:46 AM Dan Carpenter <dan.carpenter@oracle.com> wrote:
> > > > > > > >
> > > > > > > > On Sun, Jan 23, 2022 at 01:41:52PM -0500, Alexander Aring wrote:
> > > > > > > > >
> > > > > > > > > I see also:
> > > > > > > > >
> > > > > > > > > fs/dlm/midcomms.c:213:1: sparse: sparse: symbol
> > > > > > > > > '__srcu_struct_nodes_srcu' was not declared. Should it be static?
> > > > > > > > >
> > > > > > > >
> > > > > > > > Why not just do this? (Untested. Maybe I don't understand?)
> > > > > > > >
> > > > > > > > diff --git a/include/linux/srcutree.h b/include/linux/srcutree.h
> > > > > > > > index cb1f4351e8ba..a164089abec4 100644
> > > > > > > > --- a/include/linux/srcutree.h
> > > > > > > > +++ b/include/linux/srcutree.h
> > > > > > > > @@ -121,7 +121,7 @@ struct srcu_struct {
> > > > > > > > #ifdef MODULE
> > > > > > > > # define __DEFINE_SRCU(name, is_static) \
> > > > > > > > is_static struct srcu_struct name; \
> > > > > > > > - struct srcu_struct * const __srcu_struct_##name \
> > > > > > > > + is_static struct srcu_struct * const __srcu_struct_##name \
> > > > > > > > __section("___srcu_struct_ptrs") = &name
> > > > > > > > #else
> > > > > > > > # define __DEFINE_SRCU(name, is_static) \
> > > > > > > >
> > > > > > >
> > > > > > > I tried it and yes it will fix the issue and introduce another one
> > > > > > > about "is_static struct srcu_struct * const __srcu_struct_##name" is
> > > > > > > unused ("-Wunused-const-variable").
> > > > > > > I added a __maybe_unused after the introduced is_static and it seems
> > > > > > > to fix the introduced issue, now it compiles and sparse is happy. I am
> > > > > > > not sure if this is the right fix?
> > > > > >
> > > > > > it is obviously unused, but it has something to do with
> > > > > > "__section("___srcu_struct_ptrs")" and during module loading it, I
> > > > > > suppose, srcu tries to access it to find whatever needs to be
> > > > > > registered?
> > > > >
> > > > > Sorry, but if this is true then it can't be declared as static... and
> > > > > we are at the beginning again.
> > > >
> > > > Welcome to my world!!! ;-)
> > > >
> > > > More seriously, thank you for chasing this down. But would it work to
> > > > add a declaration just before?
> > > >
> > >
> > > only if I add an "extern" in front of the declaration before, so it looks like:
> > >
> > > extern struct srcu_struct * const __srcu_struct_##name;
> > >
> > > (compile and sparse tested only)
> >
> > If that works for everyone, it seems worth persuing.
> >
> > One way to test this is as follows:
> >
> > 1. Build a kernel with CONFIG_RCU_TORTURE_TEST=m. Boot this and
> > type "modprobe rcutorture torture_type=srcu".
> >
> > If you want to stop the torture test, type "rmmod rcutorture".
> >
> > This will test DEFINE_SRCU() for the module case.
> >
>
> I tested this case, I still need to do the 2. case. Sorry I am quite
> busy with something else, but I am still working on it.
>
I did the 2. test successful...:
"tools/testing/selftests/rcutorture/bin/kvm.sh --allcpus --duration 3
--configs 'SRCU-N' --trust-make"
but I was required to hack it because my "qemu-system-x86_64" did not
exist, it was "/usr/libexec/qemu-kvm" (it was able to run by just
doing a symlink). I think I already cc'd the right people to report
this issue (rcu subsystem)...
I will send a patch for the export declaration soon as possible.
- Alex
prev parent reply other threads:[~2022-01-26 14:40 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <202201221028.YKA8kSdm-lkp@intel.com>
[not found] ` <CAK-6q+h_hb94J3DSXPk=E44kCxiwZ+BE3kMJe09iShRzMb=vzQ@mail.gmail.com>
[not found] ` <91901e7b-7d82-116c-aaf2-c74c6a6b999c@infradead.org>
2022-01-23 18:41 ` fs/dlm/midcomms.c:913:22: sparse: sparse: restricted __le32 degrades to integer Alexander Aring
2022-01-24 12:45 ` Dan Carpenter
2022-01-24 17:21 ` Alexander Aring
2022-01-24 17:36 ` Alexander Aring
2022-01-24 17:41 ` Alexander Aring
2022-01-24 20:14 ` Paul E. McKenney
2022-01-24 21:36 ` Alexander Aring
2022-01-24 22:06 ` Paul E. McKenney
2022-01-25 22:35 ` Alexander Aring
2022-01-26 14:39 ` Alexander Aring [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAK-6q+gye79SDL-zh6Uq_-oCa1gMELVi_riuqnBs-EPYfyNbow@mail.gmail.com \
--to=aahringo@redhat.com \
--cc=cluster-devel@redhat.com \
--cc=dan.carpenter@oracle.com \
--cc=kbuild-all@lists.01.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-sparse@vger.kernel.org \
--cc=lkp@intel.com \
--cc=paulmck@kernel.org \
--cc=rcu@vger.kernel.org \
--cc=rdunlap@infradead.org \
--cc=teigland@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).