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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 D799BC43331 for ; Fri, 3 Apr 2020 12:41:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A63B72078C for ; Fri, 3 Apr 2020 12:41:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="P2AND8XD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390823AbgDCMlS (ORCPT ); Fri, 3 Apr 2020 08:41:18 -0400 Received: from merlin.infradead.org ([205.233.59.134]:52842 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727965AbgDCMlS (ORCPT ); Fri, 3 Apr 2020 08:41:18 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.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=7SS9MeRqSIElKXBRRy/iM4tRtXsvU9V0Neex/siiw+s=; b=P2AND8XDBYw3d2Id4IRc9mwrxE tq2sRN+RoWfEVbGiXT5nCB0U0fSg5yO9uAPb3NWuQsRB6e9hz1hzaMzupRufuDY72KkRMg8Lhlgoj 9OHHbSzSdRXdjKwqHQcy0byZO3ZJWln8noUjsFrSUqq+jyqF7C6tBb/gtB1vj/jGuLUPRax+inG25 ITjW5m9mHy56hkGf90PZe2CTFhXQE4m1SArQGl+Yt/BbiRKNlwAZNCahDLx4pAVxVE8qyDNbq+rBH 4fmLzA2Wepsy8pHPYbKLFewJI45tb3OAjG2NTrd1aX4XXPxxzW0jvAaANaXue+zzWXD4VCcFaHeqC qKwUGF1g==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jKLdG-0006eI-LD; Fri, 03 Apr 2020 12:41:10 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id A88A830477A; Fri, 3 Apr 2020 14:41:07 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 9161D2B12078B; Fri, 3 Apr 2020 14:41:07 +0200 (CEST) Date: Fri, 3 Apr 2020 14:41:07 +0200 From: Peter Zijlstra To: Julien Thierry Cc: Josh Poimboeuf , Alexandre Chartre , x86@kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de Subject: Re: [PATCH 3/7] objtool: Add support for intra-function calls Message-ID: <20200403124107.GO20730@hirez.programming.kicks-ass.net> References: <20200402082220.808-1-alexandre.chartre@oracle.com> <20200402082220.808-4-alexandre.chartre@oracle.com> <20200402154919.2c6shw4hfreagchg@treble> <3d075cb2-8d99-5ab7-4842-efef1964247d@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3d075cb2-8d99-5ab7-4842-efef1964247d@redhat.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 03, 2020 at 09:01:38AM +0100, Julien Thierry wrote: > > Last I found is in qcom_link_stack_sanitization() [2], but that's just a > workaround for a very specific hardware. In my local tree I just put the > function as STACK_FRAME_NON_STANDARD. But the code just saves the return > address, has 16 call instructions that just call the instruction after them, > restores the return address and lets the C-function return normally (and it > somehow fixes something for that hardware). > That sounds very much like the RSB flushing we do.