Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Fri, 23 Aug 2019 11:24:27 -0300
From:   Jason Gunthorpe <jgg@ziepe.ca>
To:     Nathan Chancellor <natechancellor@gmail.com>
Cc:     Nick Desaulniers <ndesaulniers@google.com>,
        Bernard Metzler <BMT@zurich.ibm.com>,
        Doug Ledford <dledford@redhat.com>, linux-rdma@vger.kernel.org,
        LKML <linux-kernel@vger.kernel.org>,
        clang-built-linux <clang-built-linux@googlegroups.com>
Subject: Re: [PATCH] rdma/siw: Use proper enumerated type in map_cqe_status
Message-ID: <20190823142427.GD12968@ziepe.ca>
References: <20190710174800.34451-1-natechancellor@gmail.com>
 <OFE93E0F86.E35CE856-ON00258434.002A83CE-00258434.002A83DF@notes.na.collabserv.com>
 <20190711081434.GA86557@archlinux-threadripper>
 <20190711133915.GA25807@ziepe.ca>
 <CAKwvOdnHz3uH4ZM20LGQJ3FYhLQQUYn4Lg0B-YMr7Y1L66TAsA@mail.gmail.com>
 <20190711171808.GF25807@ziepe.ca>
 <20190711173030.GA844@archlinux-threadripper>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20190711173030.GA844@archlinux-threadripper>
User-Agent: Mutt/1.9.4 (2018-02-28)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Thu, Jul 11, 2019 at 10:30:30AM -0700, Nathan Chancellor wrote:
> On Thu, Jul 11, 2019 at 02:18:08PM -0300, Jason Gunthorpe wrote:
> > On Thu, Jul 11, 2019 at 10:16:44AM -0700, Nick Desaulniers wrote:
> > > On Thu, Jul 11, 2019 at 6:39 AM Jason Gunthorpe <jgg@ziepe.ca> wrote:
> > > >
> > > > On Thu, Jul 11, 2019 at 01:14:34AM -0700, Nathan Chancellor wrote:
> > > > > Maybe time to start plumbing Clang into your test flow until it can get
> > > > > intergrated with more CI setups? :) It can catch some pretty dodgy
> > > > > behavior that GCC doesn't:
> > > >
> > > > I keep asking how to use clang to build the kernel and last I was told
> > > > it still wasn't ready..
> > > >
> > > > Is it ready now? Is there some flow that will compile with clang
> > > > warning free, on any arch? (at least the portion of the kernel I check)
> > > 
> > > $ make CC=clang ...
> > > 
> > > Let us know if you find something we haven't already.
> > > https://clangbuiltlinux.github.io/
> > > https://github.com/ClangBuiltLinux/linux/issues
> > 
> > What clang version?
> > 
> > Jason
> 
> You'll need clang-9 for x86 because of the asm-goto requirement (or a
> selective set of reverts for clang-8) but everything else should be
> good with clang-8:

The latest clang-9 packages from apt.llvm.org do seem to build the
kernel, I get one puzzling warning under RDMA:

drivers/infiniband/hw/hfi1/platform.o: warning: objtool: tune_serdes()+0x1f4: can't find jump dest instruction at .text+0x118a

And a BPF one:

kernel/bpf/core.o: warning: objtool: ___bpf_prog_run()+0xd: sibling call from callable instruction with modified stack frame

Jason