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[2620:137:e000::1:20]) by mx.google.com with ESMTP id i15-20020a50cfcf000000b0041003a1e4a9si4077709edk.440.2022.03.04.12.25.53; Fri, 04 Mar 2022 12:26:19 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@infradead.org header.s=casper.20170209 header.b=ZySsesB8; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229812AbiCDUXm (ORCPT + 99 others); Fri, 4 Mar 2022 15:23:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57390 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229746AbiCDUXk (ORCPT ); Fri, 4 Mar 2022 15:23:40 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 348AD1D06E5 for ; Fri, 4 Mar 2022 12:22:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=uVPrSHaqLF9b3ORXlMh5Qj9V4zOmWj8SncI5qbaLawc=; b=ZySsesB8Tuo0Fb1eYIXWq5nFbA bObP7Pnz7h8twGUphf7sKoXp5ybJxhj/q7W8OZvVKDEIEzmULQKSpj/4pF9WAfO7p3g2U+UzRsB2r eDE2VG5gYqZwGsD8uqy47SISepW457EcJDvVNCdC35/I8yEeSKsucLvHm5+RC2PDBKVmBQdx9jXy3 4YO9xaJK+rZXZTbWhtN+M0y6ezpGhIdeCCp+t8AeAvgxr/RAN6hmeiKXrGoJ0YTEyI/u2CtS2MxLz +ncRkx/hsMMuuWW64MZqfR1VPEWYcizNzvPkverh2buh9Hc7hiZVvf4dy8UAsqQfGLOtZEr+cCFKZ u4em/8ew==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=worktop.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1nQERW-00Cz2o-Ff; Fri, 04 Mar 2022 20:22:26 +0000 Received: by worktop.programming.kicks-ass.net (Postfix, from userid 1000) id 4D2E198624E; Fri, 4 Mar 2022 21:22:25 +0100 (CET) Date: Fri, 4 Mar 2022 21:22:25 +0100 From: Peter Zijlstra To: Josh Poimboeuf Cc: x86@kernel.org, joao@overdrivepizza.com, hjl.tools@gmail.com, andrew.cooper3@citrix.com, linux-kernel@vger.kernel.org, ndesaulniers@google.com, keescook@chromium.org, samitolvanen@google.com, mark.rutland@arm.com, 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 Message-ID: <20220304202225.GO11184@worktop.programming.kicks-ass.net> References: <20220303112321.422525803@infradead.org> <20220304190958.comlw5wt7zdgeakc@treble> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220304190958.comlw5wt7zdgeakc@treble> X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED,SPF_HELO_NONE, SPF_NONE,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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..