Date:   Sun, 29 Jan 2023 07:51:04 -0700
From:   Nathan Chancellor <nathan@kernel.org>
To:     Arnd Bergmann <arnd@arndb.de>
Cc:     Russell King <linux@armlinux.org.uk>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Tom Rix <trix@redhat.com>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        llvm@lists.linux.dev, patches@lists.linux.dev
Subject: Re: [PATCH] ARM: Allow pre-ARMv5 builds with ld.lld 16.0.0 and newer
Message-ID: <Y9aH2AzDpwQXFlx+@dev-arch.thelio-3990X>
References: <20230118-v4-v4t-lld-16-v1-1-e3d9a00ae47c@kernel.org>
 <1206e990-23b3-44c8-97c9-869ec0aeead0@app.fastmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <1206e990-23b3-44c8-97c9-869ec0aeead0@app.fastmail.com>
Precedence: bulk

On Fri, Jan 27, 2023 at 10:56:06PM +0100, Arnd Bergmann wrote:
> On Wed, Jan 18, 2023, at 20:22, Nathan Chancellor wrote:
> > Commit 6a7ee50f8f56 ("ARM: disallow pre-ARMv5 builds with ld.lld")
> > prevented v4 or v4t kernels when ld.lld will link the kernel due to
> > inserting unsupported blx instructions.
> >
> > ld.lld has been fixed in current main (16.0.0) to avoid inserting these
> > instructions by inserting position independent thunks instead. Allow
> > these configurations to be enabled when ld.lld 16.0.0 is used to link
> > the kernel.
> >
> > Additionally, add a link to the upstream LLVM issue so that the reason
> > for this dependency is clearly documented.
> >
> > Link: https://github.com/ClangBuiltLinux/linux/issues/964
> > Link: 
> > https://github.com/llvm/llvm-project/commit/6f9ff1beee9d12aca0c9caa9ae0051dc6d0a718c
> > Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
> > Signed-off-by: Nathan Chancellor <nathan@kernel.org>
> 
> Thanks a lot for getting this fixed!
> 
> I gave this a spin on my randconfig build setup, which showed
> nothing unusual.
> 
> Tested-by: Arnd Bergmann <arnd@arndb.de>
> 
> Please add this to Russell's patch tracker.

Done, thanks for testing!

https://www.armlinux.org.uk/developer/patches/viewpatch.php?id=9289/1

Cheers,
Nathan