From: Nick Desaulniers <ndesaulniers@google.com>
To: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>, Rong Chen <rong.a.chen@intel.com>,
kernel test robot <lkp@intel.com>,
"Li, Philip" <philip.li@intel.com>, x86-ml <x86@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
clang-built-linux <clang-built-linux@googlegroups.com>
Subject: Re: [tip:x86/seves] BUILD SUCCESS WITH WARNING e6eb15c9ba3165698488ae5c34920eea20eaa38e
Date: Tue, 15 Sep 2020 10:44:51 -0700 [thread overview]
Message-ID: <CAKwvOdncdq4nMN1dXv_+3rC84wGEJtmgiyNTHNhCQi+ouqaB7A@mail.gmail.com> (raw)
In-Reply-To: <20200915170248.gcv54pvyckteyhk3@treble>
On Tue, Sep 15, 2020 at 10:02 AM Josh Poimboeuf <jpoimboe@redhat.com> wrote:
>
> On Tue, Sep 15, 2020 at 06:05:54PM +0200, Borislav Petkov wrote:
> > On Tue, Sep 15, 2020 at 10:18:16PM +0800, Rong Chen wrote:
> > > On Tue, Sep 15, 2020 at 03:55:19PM +0200, Borislav Petkov wrote:
> > > > On Tue, Sep 15, 2020 at 09:42:56PM +0800, kernel test robot wrote:
> > > > > tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git x86/seves
> > > > > branch HEAD: e6eb15c9ba3165698488ae5c34920eea20eaa38e KVM: nSVM: Avoid freeing uninitialized pointers in svm_set_nested_state()
> > > > >
> > > > > Warning in current branch:
> > > > >
> > > > > arch/x86/kernel/sev-es.o: warning: objtool: ist_exc_vmm_communication()+0x12: unreachable instruction
> > > > >
> > > > > Warning ids grouped by kconfigs:
> > > > >
> > > > > clang_recent_errors
> > > > > `-- x86_64-randconfig-r001-20200913
> > > > > `-- arch-x86-kernel-sev-es.o:warning:objtool:ist_exc_vmm_communication():unreachable-instruction
> >
> > Ok, I can't trigger this with gcc-9, gcc-10 and clang-10.
> >
> > .config below says clang-12 so it could be some experimental
> > bug^Wfeature :)
> >
> > peterz says this has been fixed by:
> >
> > 318af7b80b6a ("Revert "kbuild: use -flive-patching when CONFIG_LIVEPATCH is enabled"")
> >
> > but that was reportedly for gcc.
> >
> > Lemme Cc the people of interest and leave the rest in here for
> > reference. Note that CONFIG_LIVEPATCH is enabled in that .config.
>
> If somebody can share the .o file, I can take a look.
I'm cc'ed on and read every report from 0day bot from builds with
Clang. I started noticing a few randconfigs getting this report from
objtool. I had filed a bug to follow up on this:
https://github.com/ClangBuiltLinux/linux/issues/1148. They all seem
to be coming from randconfigs. I've not yet had the time to bisect
configs to isolate which config this is coming from, but I wouldn't be
surprised if it was UBSAN.
--
Thanks,
~Nick Desaulniers
next prev parent reply other threads:[~2020-09-15 17:59 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-15 13:42 [tip:x86/seves] BUILD SUCCESS WITH WARNING e6eb15c9ba3165698488ae5c34920eea20eaa38e kernel test robot
2020-09-15 13:55 ` Borislav Petkov
2020-09-15 14:18 ` Rong Chen
2020-09-15 14:41 ` Borislav Petkov
2020-09-15 16:05 ` Borislav Petkov
2020-09-15 17:02 ` Josh Poimboeuf
2020-09-15 17:21 ` Borislav Petkov
2020-09-15 17:34 ` Borislav Petkov
2020-09-15 17:41 ` Nick Desaulniers
2020-09-15 18:01 ` Borislav Petkov
2020-09-15 18:04 ` Nick Desaulniers
2020-09-15 17:40 ` Nick Desaulniers
2020-09-15 18:09 ` Marco Elver
2020-09-16 8:30 ` peterz
2020-09-16 8:46 ` Marco Elver
2020-09-16 9:06 ` peterz
2020-09-16 9:33 ` Marco Elver
2020-09-16 18:22 ` Nick Desaulniers
2020-09-16 18:51 ` Marco Elver
2020-09-17 4:11 ` Fangrui Song
[not found] ` <333D40A0-4550-4309-9693-1ABA4AC75399@arm.com>
2020-09-17 11:04 ` Mark Rutland
2020-09-17 11:16 ` Daniel Kiss
2020-09-17 18:39 ` Josh Poimboeuf
2020-09-15 17:44 ` Nick Desaulniers [this message]
2020-09-15 20:12 ` Nick Desaulniers
2020-09-15 20:49 ` Borislav Petkov
2020-09-15 21:02 ` Josh Poimboeuf
2020-09-15 21:14 ` Borislav Petkov
2020-09-15 22:34 ` Nick Desaulniers
2020-09-16 7:03 ` Ilie Halip
2020-09-16 8:59 ` Marco Elver
2020-09-21 16:51 ` [tip: objtool/core] objtool: Ignore unreachable trap after call to noreturn functions tip-bot2 for Ilie Halip
2020-09-15 21:50 ` [tip:x86/seves] BUILD SUCCESS WITH WARNING e6eb15c9ba3165698488ae5c34920eea20eaa38e Arvind Sankar
2020-09-15 21:59 ` Nick Desaulniers
2020-09-15 22:44 ` Arvind Sankar
2020-09-16 11:34 ` Borislav Petkov
2020-09-16 18:28 ` Nick Desaulniers
2020-09-16 18:48 ` Borislav Petkov
2020-09-15 21:13 ` Nick Desaulniers
2020-09-15 21:28 ` Josh Poimboeuf
2020-09-15 23:35 ` Marco Elver
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