Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
MIME-Version: 1.0
References: <CAK8P3a2qLJkokMGt48JRky=WUeAbJRuNmoD1oqfWdrGSC6y1LA@mail.gmail.com>
In-Reply-To: <CAK8P3a2qLJkokMGt48JRky=WUeAbJRuNmoD1oqfWdrGSC6y1LA@mail.gmail.com>
From:   Arnd Bergmann <arnd@arndb.de>
Date:   Thu, 30 Apr 2020 16:05:07 +0200
Message-ID: <CAK8P3a2Gzj9SVZSGo+PxWR0cMJb1sFwv+ii9J6jEGE-Z41Fr+A@mail.gmail.com>
Subject: Re: Remaining randconfig objtool warnings, linux-next-20200428
To:     Josh Poimboeuf <jpoimboe@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        "the arch/x86 maintainers" <x86@kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Tue, Apr 28, 2020 at 4:49 PM Arnd Bergmann <arnd@arndb.de> wrote:
>
> I noticed the number of objtool warnings in randconfig kernels have gone down
>  recently, maybe it's possible to eliminate the remaining ones?
>
> Here are the ones I ran into recently, using gcc-9.3:

I now cross-checked with gcc-10.0, which leads to a few additional warnings
for randconfig builds:

drivers/gpu/drm/vmwgfx/vmwgfx_msg.o: warning: objtool:
vmw_port_hb_in()+0x12f: stack state mismatch: cfa1=6+16 cfa2=7+8
drivers/gpu/drm/vmwgfx/vmwgfx_msg.o: warning: objtool:
vmw_port_hb_in()+0xca: return with modified stack frame
drivers/media/dvb-frontends/rtl2832_sdr.o: warning: objtool:
.text.unlikely: unexpected end of section
drivers/media/dvb-frontends/rtl2832_sdr.o: warning: objtool:
rtl2832_sdr_try_fmt_sdr_cap() falls through to next function
rtl2832_sdr_s_fmt_sdr_cap.cold()
kernel/kexec_core.o: warning: objtool: crash_kexec()+0x2b: unreachable
instruction
lib/locking-selftest.o: warning: objtool: locking_selftest()+0x117f:
PUSHF stack exhausted
lib/locking-selftest.o: warning: objtool: ww_tests()+0x1083: PUSHF
stack exhausted
lib/strncpy_from_user.o: warning: objtool: strncpy_from_user()+0x133:
call to do_strncpy_from_user() with UACCESS enabled
lib/strnlen_user.o: warning: objtool: strnlen_user()+0x122: call to
do_strnlen_user() with UACCESS enabled

I uploaded these as well now, see
https://drive.google.com/open?id=1k10cO9OkFKaMVnK7uX-prplY-13CAvW1

       Arnd