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 X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B6F00C433DB for ; Wed, 10 Mar 2021 15:09:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7C11464F4B for ; Wed, 10 Mar 2021 15:09:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232299AbhCJPJV (ORCPT ); Wed, 10 Mar 2021 10:09:21 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:56414 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229602AbhCJPI7 (ORCPT ); Wed, 10 Mar 2021 10:08:59 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1615388939; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=/y/H0bJShEAqvQ118GFOubDIFXmTHRwvOstt+Xw9FT4=; b=cne97lfS6ydlZQ+h2Pd5s/RKkDXXOoh8/7FZiTc2dVtK5cSkZGhFivfdExpMI7FZ4kysCK yI9/Urejl3eDrwwPuzdKNQBOxOja11gTZEnDXbhehutcY/uaTrjDpAURcq/VISHcAV58a0 2PjoUU/AFPwYr8+gr2dsteYHus4/ovs= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-391-uRWwTBJvOv2zTtGDi6k1yA-1; Wed, 10 Mar 2021 10:08:55 -0500 X-MC-Unique: uRWwTBJvOv2zTtGDi6k1yA-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1B8632F7A4; Wed, 10 Mar 2021 15:08:53 +0000 (UTC) Received: from treble (ovpn-118-249.rdu2.redhat.com [10.10.118.249]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 17D9A5C1A1; Wed, 10 Mar 2021 15:08:48 +0000 (UTC) Date: Wed, 10 Mar 2021 09:08:45 -0600 From: Josh Poimboeuf To: Masami Hiramatsu Cc: Daniel Xu , Steven Rostedt , Ingo Molnar , X86 ML , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, tglx@linutronix.de, kernel-team@fb.com, yhs@fb.com Subject: Re: [PATCH -tip 0/5] kprobes: Fix stacktrace in kretprobes Message-ID: <20210310150845.7kctaox34yrfyjxt@treble> References: <161495873696.346821.10161501768906432924.stgit@devnote2> <20210305191645.njvrsni3ztvhhvqw@maharaja.localdomain> <20210306101357.6f947b063a982da9c949f1ba@kernel.org> <20210307212333.7jqmdnahoohpxabn@maharaja.localdomain> <20210308115210.732f2c42bf347c15fbb2a828@kernel.org> <20210309011945.ky7v3pnbdpxhmxkh@treble> <20210310185734.332d9d52a26780ba02d09197@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210310185734.332d9d52a26780ba02d09197@kernel.org> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Wed, Mar 10, 2021 at 06:57:34PM +0900, Masami Hiramatsu wrote: > > If I understand correctly, for #1 you need an unwind hint which treats > > the instruction *after* the "pushq %rsp" as the beginning of the > > function. > > Thanks for the patch. In that case, should I still change the stack allocation? > Or can I continue to use a series of "push/pop" ? You can continue to use push/pop. Objtool is only getting confused by the unbalanced stack of the function (more pushes than pops). The unwind hint should fix that. -- Josh