From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2687EC433F5 for ; Tue, 2 Nov 2021 08:03:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0A98761051 for ; Tue, 2 Nov 2021 08:03:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229970AbhKBIFr (ORCPT ); Tue, 2 Nov 2021 04:05:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38640 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229505AbhKBIFo (ORCPT ); Tue, 2 Nov 2021 04:05:44 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5AC3CC061714 for ; Tue, 2 Nov 2021 01:03:09 -0700 (PDT) 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=rMcaU0eXNJrQzQEGjllDL02FizhCwJm5AcvCOAERMAk=; b=DJ/r/DbPU1N+tG8eTERztYDKZX vEpPchywZxXvrlKBaYXzlF5z8d4aQhh0RJeUMqB2JZTD+nVy+9vY29QAOkCVxHXFi1F5Pp4uPwdJz 790L6QY6KX6iZbc9sVwHj7ToVCJax039RCz49vshYkWDNBkA1SS2G8yvBGa83T+Andqj0V2+R/sA2 xQbHuE4rA2J0Y+VyQCcoN3SHGC5UuMWm/vUrv92g73gKmN2Z/6EGKd3Lm31RW9lk3Q7xkb8pWkR7B W+nmtlEHiO4m3nUJPN5Wjfm7ehzmgkg1zwjI9sZ/be6wcWVH0W5mveyzKNu5elI9P8i/KYkuFAdm7 3Ibg+Lfw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1mhoij-004M5X-Sc; Tue, 02 Nov 2021 08:00:57 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 3DC93300130; Tue, 2 Nov 2021 09:00:36 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 2BE052D202F07; Tue, 2 Nov 2021 09:00:36 +0100 (CET) Date: Tue, 2 Nov 2021 09:00:36 +0100 From: Peter Zijlstra To: Linus Torvalds Cc: Thomas Gleixner , Josh Poimboeuf , Linux Kernel Mailing List , the arch/x86 maintainers Subject: Re: [GIT pull] objtool/core for v5.16-rc1 Message-ID: References: <163572864256.3357115.931779940195622047.tglx@xen13> <163572864563.3357115.8793939214537874196.tglx@xen13> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 01, 2021 at 01:44:39PM -0700, Linus Torvalds wrote: > On Sun, Oct 31, 2021 at 6:16 PM Thomas Gleixner wrote: > > > > please pull the latest objtool/core branch from: > > Hmm. I've pulled this, but I'm not happy about the new warnings it > generates with an allmodconfig build: Right, due to fixing the dependency on !PARAVIRT, allyesconfig now does a noinstr validation, and this is the result. > vmlinux.o: warning: objtool: __do_fast_syscall_32()+0xa: call to > stackleak_track_stack() leaves .noinstr.text section > .. > mce_setup()+0x18: call to memset ... Boris was having a poke at the MCE stuff. > rcu_dynticks_eqs_enter()+0x0: call to rcu_dynticks_task_trace_enter ... > rcu_dynticks_eqs_exit()+0xe: call to rcu_dynticks_task_trace_exit ... > rcu_nmi_enter()+0x36: call to __kasan_check_read ... Fixes for those ^ should be in the rcu tree. There were also a bunch of Xen ones that should be fixed in the Xen tree, perhaps you've already pulled that. > do_machine_check()+0x27: call to stackleak_track_stack ... > do_syscall_64()+0x9: call to stackleak_track_stack ... > do_int80_syscall_32()+0x9: call to stackleak_track_stack ... > exc_general_protection()+0x22: call to stackleak_track_stack ... > fixup_bad_iret()+0x20: call to stackleak_track_stack ... > .entry.text+0x10e6: call to stackleak_erase ... > .entry.text+0x143: call to stackleak_erase ... > .entry.text+0x17d9: call to stackleak_erase ... > > most seem to be about the stackleak thing, Right, I recently ran into this and hacen't yet had time to look into it. I suspect my normal build box doesn't have the GCC plugin crud enabled or somesuch. I think the GCC stackleak plugin needs fixing, specifically it needs a function attribute such that it will not emit instrumentation in noinstr functions. I'll go chase down the developer of that thing.