Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18;
Date:   Mon, 21 Mar 2022 16:45:40 +0100
From:   Peter Zijlstra <peterz@infradead.org>
To:     Stephen Rothwell <sfr@canb.auug.org.au>
Cc:     Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>,
        "H. Peter Anvin" <hpa@zytor.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux Next Mailing List <linux-next@vger.kernel.org>,
        mhiramat@kernel.org, rostedt@goodmis.org, ast@kernel.org,
        hjl.tools@gmail.com, rick.p.edgecombe@intel.com, rppt@kernel.org,
        linux-toolchains@vger.kernel.org, Andrew.Cooper3@citrix.com,
        ndesaulniers@google.com,
        Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: linux-next: build warnings after merge of the tip tree
Message-ID: <YjidpOZZJkF6aBTG@hirez.programming.kicks-ass.net>
References: <20220321140327.777f9554@canb.auug.org.au>
 <Yjh11UjDZogc3foM@hirez.programming.kicks-ass.net>
 <Yjh3xZuuY3QcZ1Bn@hirez.programming.kicks-ass.net>
 <Yjh4xzSWtvR+vqst@hirez.programming.kicks-ass.net>
 <YjiBbF+K4FKZyn6T@hirez.programming.kicks-ass.net>
 <YjiZhRelDJeX4dfR@hirez.programming.kicks-ass.net>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <YjiZhRelDJeX4dfR@hirez.programming.kicks-ass.net>
Precedence: bulk

On Mon, Mar 21, 2022 at 04:28:06PM +0100, Peter Zijlstra wrote:
> On Mon, Mar 21, 2022 at 02:45:16PM +0100, Peter Zijlstra wrote:
> > On Mon, Mar 21, 2022 at 02:08:23PM +0100, Peter Zijlstra wrote:
> > > On Mon, Mar 21, 2022 at 02:04:05PM +0100, Peter Zijlstra wrote:
> > > > On Mon, Mar 21, 2022 at 01:55:49PM +0100, Peter Zijlstra wrote:
> > > > > On Mon, Mar 21, 2022 at 02:03:27PM +1100, Stephen Rothwell wrote:
> > > > > > Hi all,
> > > > > > 
> > > > > > After merging the tip tree, today's linux-next build (x864 allmodconfig)
> > > > > > produced these new warnings:
> > > > > > 
> > > > > > vmlinux.o: warning: objtool: arch_rethook_prepare()+0x55: relocation to !ENDBR: arch_rethook_trampoline+0x0
> > > > > > vmlinux.o: warning: objtool: arch_rethook_trampoline_callback()+0x3e: relocation to !ENDBR: arch_rethook_trampoline+0x0
> > > > > > vmlinux.o: warning: objtool: unwind_next_frame()+0x93e: relocation to !ENDBR: arch_rethook_trampoline+0x0
> > > > > > vmlinux.o: warning: objtool: unwind_next_frame()+0x5f2: relocation to !ENDBR: arch_rethook_trampoline+0x0
> > > > > > vmlinux.o: warning: objtool: unwind_next_frame()+0x4a7: relocation to !ENDBR: arch_rethook_trampoline+0x0
> > > > > > vmlinux.o: warning: objtool: __rethook_find_ret_addr()+0x81: relocation to !ENDBR: arch_rethook_trampoline+0x0
> > > > > > vmlinux.o: warning: objtool: __rethook_find_ret_addr()+0x90: relocation to !ENDBR: arch_rethook_trampoline+0x0
> > > > > > vmlinux.o: warning: objtool: rethook_trampoline_handler()+0x8c: relocation to !ENDBR: arch_rethook_trampoline+0x0
> > > > > > vmlinux.o: warning: objtool: rethook_trampoline_handler()+0x9b: relocation to !ENDBR: arch_rethook_trampoline+0x0
> > > > > 
> > > > > Hurmph, lemme go figure out where that code comes from, I've not seen
> > > > > those.
> > > > 
> > > > Ahh, something tracing. I'll go do some patches on top of it.
> > > 
> > > Also, that x86 patch has never his x86@kernel.org and doesn't have an
> > > ACK from any x86 person :-(((
> > 
> > Worse, it adds a 3rd return trampoline without replacing any of the
> > existing two :-(
> > 
> > Why was this merged?
> 
> It additionally gets ret wrong:
> 
>   vmlinux.o: warning: objtool: arch_rethook_trampoline()+0x4a: missing int3 after ret
> 
> and afaict regs->ss is garbage (much like kretprobes it appears).
> 
> Can we please unmerge this stuff and try again later?

This landing in -next only today (after having been committed last
friday night) is another clue it should probably go next round.