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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3B2DCC4332F for ; Fri, 14 Oct 2022 22:45:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229525AbiJNWpC (ORCPT ); Fri, 14 Oct 2022 18:45:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37894 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229555AbiJNWpB (ORCPT ); Fri, 14 Oct 2022 18:45:01 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9957B27CC9; Fri, 14 Oct 2022 15:44:58 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 588A4B82447; Fri, 14 Oct 2022 22:44:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6E4BEC433C1; Fri, 14 Oct 2022 22:44:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1665787495; bh=76auTpYAGb5cdGloWPsQFXvwKjAB8wQIcC8hAOFyJ4Q=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=JpKcL3K2iulReMROCM55Cs+TE2+e0d+NAM+jMxEljicqOmnKqHujg5jMf6hwNw/bP ATSlDOcQ5mTqZqc7zQrln7DFflbdDgzamUeSxhfunuNSTjEadOSOYlp57FcHovP4jW WhZSNA6t+4jzhubRKOLhZ1nZAJTWcnTCi09ovzU0EGcbZA4nqpMpe2MbQKf0x+z/mi uuCNvTa9TqpAa3ISdJh+j0qp9uePc9/5qC9UZagS5/o1Rmm8Qt5QS/d7ZX6Hf+vGbe /8U3svS4kx4SEHa8vj8bKFbMaAhESTvefXV4rXo/NPDWUvRal+gVE7IrKCyYNF1rmI 3mVvLa35kicmw== Date: Fri, 14 Oct 2022 15:44:53 -0700 From: Josh Poimboeuf To: Chen Zhongjin Cc: linux-kernel@vger.kernel.org, x86@kernel.org, linux-arch@vger.kernel.org, peterz@infradead.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, mbenes@suse.cz Subject: Re: [PATCH] Revert "x86/unwind/orc: Don't skip the first frame for inactive tasks" Message-ID: <20221014224453.5upiioslqjzo2bow@treble> References: <20220727031506.59322-1-chenzhongjin@huawei.com> <20220804045518.bfhe3rxhpkxzn4hk@treble> <5ee1dfb5-fa70-d412-43c2-3e90ee057eec@huawei.com> <20220804220623.a2s7ucblryudm63m@treble> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org On Sun, Oct 09, 2022 at 11:14:05AM +0800, Chen Zhongjin wrote: > Hi Josh, > > On 2022/8/5 6:06, Josh Poimboeuf wrote: > > On Thu, Aug 04, 2022 at 03:27:39PM +0800, Chen Zhongjin wrote: > > > I believe disassemble show_stack in vmlinux and if we have: > > > > > >     push   %rbp > > > > > >     mov    %rsp,%rbp > > > > > >     ... (no regs pushed to stack) > > > > > >     callq  > > > > > > This can be reproduced. > > Weird, that's what I have. This is GCC 12.1. > > > > ffffffff81056de0 : > > ffffffff81056de0: e8 0b 43 05 00 call ffffffff810ab0f0 <__fentry__> > > ffffffff81056de5: 55 push %rbp > > ffffffff81056de6: 48 83 05 b2 0f c9 02 01 addq $0x1,0x2c90fb2(%rip) # ffffffff83ce7da0 <__gcov0.show_stack> > > ffffffff81056dee: 48 89 e5 mov %rsp,%rbp > > ffffffff81056df1: 48 85 ff test %rdi,%rdi > > ffffffff81056df4: 74 41 je ffffffff81056e37 > > ffffffff81056df6: 48 85 f6 test %rsi,%rsi > > ffffffff81056df9: 0f 85 c2 24 15 01 jne ffffffff821a92c1 > > ffffffff81056dff: 65 48 8b 04 25 c0 bd 01 00 mov %gs:0x1bdc0,%rax > > ffffffff81056e08: 48 39 c7 cmp %rax,%rdi > > ffffffff81056e0b: 0f 85 a3 24 15 01 jne ffffffff821a92b4 > > ffffffff81056e11: 48 83 05 af 0f c9 02 01 addq $0x1,0x2c90faf(%rip) # ffffffff83ce7dc8 <__gcov0.show_stack+0x28> > > ffffffff81056e19: 48 89 ee mov %rbp,%rsi > > ffffffff81056e1c: 48 89 d1 mov %rdx,%rcx > > ffffffff81056e1f: 48 89 f2 mov %rsi,%rdx > > ffffffff81056e22: 31 f6 xor %esi,%esi > > ffffffff81056e24: e8 8e 20 15 01 call ffffffff821a8eb7 > > ffffffff81056e29: 48 83 05 9f 0f c9 02 01 addq $0x1,0x2c90f9f(%rip) # ffffffff83ce7dd0 <__gcov0.show_stack+0x30> > > ffffffff81056e31: 5d pop %rbp > > ffffffff81056e32: e9 49 b2 5a 01 jmp ffffffff82602080 <__x86_return_thunk> > > ffffffff81056e37: 48 83 05 69 0f c9 02 01 addq $0x1,0x2c90f69(%rip) # ffffffff83ce7da8 <__gcov0.show_stack+0x8> > > ffffffff81056e3f: 65 48 8b 3c 25 c0 bd 01 00 mov %gs:0x1bdc0,%rdi > > ffffffff81056e48: eb ac jmp ffffffff81056df6 > > ffffffff81056e4a: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) > > This problem still exist on my machine: > > CONFIG: defconfig + CONFIG_GCOV_PROFILE_ALL > > GCC: gcc 7.5.0 & 12.1.0 > > TRIGGER: > > # echo l > /proc/sysrq-trigger Hi Chen, Thanks for your patience. I'm able to recreate now. I still have no idea why I couldn't recreate before. Anyway the patch looks good. I'll run it through some more testing. -- Josh