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Date:   Fri, 4 Mar 2022 21:22:25 +0100
From:   Peter Zijlstra <peterz@infradead.org>
To:     Josh Poimboeuf <jpoimboe@redhat.com>
Cc:     x86@kernel.org, joao@overdrivepizza.com, hjl.tools@gmail.com,
        andrew.cooper3@citrix.com, linux-kernel@vger.kernel.org,
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        alyssa.milburn@intel.com, mbenes@suse.cz, rostedt@goodmis.org,
        mhiramat@kernel.org, alexei.starovoitov@gmail.com
Subject: Re: [PATCH v3 00/39] x86: Kernel IBT
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 <20220304190958.comlw5wt7zdgeakc@treble>
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On Fri, Mar 04, 2022 at 11:09:58AM -0800, Josh Poimboeuf wrote:

> I'm getting some warnings with CONFIG_X86_KERNEL_IBT=n:
> 
>   arch/x86/entry/entry_64.o: warning: objtool: irq_entries_start()+0x7: unreachable instruction
>   arch/x86/kernel/ftrace_64.o: warning: objtool: return_to_handler()+0x2a: unreachable instruction

Urgh, lemme go chase that.

> And a warning with CONFIG_X86_KERNEL_IBT=y:
> 
>   vmlinux.o: warning: objtool: .text+0xaf0: unreachable instruction

This is that weak symbol issue :/ We talked about it on IRC, but i've
not yet come around to fixing it.

This is mostly a pre-existing issue, only uncovered because we run on
vmlinux more..