From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gateway36.websitewelcome.com (gateway36.websitewelcome.com [192.185.193.119]) by sourceware.org (Postfix) with ESMTPS id 8204A386EC3E for ; Thu, 7 Jan 2021 21:19:05 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 8204A386EC3E Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=tromey.com Authentication-Results: sourceware.org; spf=fail smtp.mailfrom=tom@tromey.com Received: from cm14.websitewelcome.com (cm14.websitewelcome.com [100.42.49.7]) by gateway36.websitewelcome.com (Postfix) with ESMTP id 0F4B3400DFE31 for ; Thu, 7 Jan 2021 15:19:05 -0600 (CST) Received: from box5379.bluehost.com ([162.241.216.53]) by cmsmtp with SMTP id xcgSknbuBsvw9xcgSk8mU1; Thu, 07 Jan 2021 15:19:05 -0600 X-Authority-Reason: nr=8 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=tromey.com; s=default; h=Content-Type:MIME-Version:Message-ID:In-Reply-To:Date: References:Subject:Cc:To:From:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=nZf5SfmBB2hBDUhDrvEfRYL3lBVX6FhJaZvH1wmwavo=; b=D65XFrIUksxFtNHEqytPmIMexm G1rW07X3Le+zrrhUfMW0adIZkH+9Y47bnDOlsc9Yd5jF3JyXh9z0czjeUNLwHyoe0NKqUwOxJtwU4 tVnNENLleM1hMtmY+ps0mn6jj; Received: from 97-122-81-39.hlrn.qwest.net ([97.122.81.39]:42262 helo=murgatroyd) by box5379.bluehost.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1kxcgS-001GVu-9b; Thu, 07 Jan 2021 14:19:04 -0700 From: Tom Tromey To: Walt Drummond via Gdb Subject: Re: AMD64_LINUX_frame_size References: X-Attribution: Tom Date: Thu, 07 Jan 2021 14:19:03 -0700 In-Reply-To: (Walt Drummond via Gdb's message of "Wed, 6 Jan 2021 08:38:59 -0800") Message-ID: <87eeiwv41k.fsf@tromey.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - box5379.bluehost.com X-AntiAbuse: Original Domain - sourceware.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - tromey.com X-BWhitelist: no X-Source-IP: 97.122.81.39 X-Source-L: No X-Exim-ID: 1kxcgS-001GVu-9b X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: 97-122-81-39.hlrn.qwest.net (murgatroyd) [97.122.81.39]:42262 X-Source-Auth: tom+tromey.com X-Email-Count: 6 X-Source-Cap: ZWx5bnJvYmk7ZWx5bnJvYmk7Ym94NTM3OS5ibHVlaG9zdC5jb20= X-Local-Domain: yes X-Spam-Status: No, score=-3025.1 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, JMQ_SPF_NEUTRAL, RCVD_IN_ABUSEAT, RCVD_IN_BARRACUDACENTRAL, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2, SPF_HELO_PASS, SPF_NEUTRAL, TXREP autolearn=no autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: gdb@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 07 Jan 2021 21:19:07 -0000 >>>>> "Walt" == Walt Drummond via Gdb writes: Walt> After looking at this further, I think I understand AMD64_LINUX_frame_size Walt> and why it differs from the size of the kernel's rt_sigframe (differences Walt> between glibc's and the kernels' definition of sigset_t), but I don't Walt> understand how GDB arrived at 512 for AMD_LINUX_xstate. The kernel's math Walt> frame, which also contains the extended state information, is 840 bytes. I Walt> feel I must be missing something. Any pointers? I don't really know, but from a quick look at this code, it seems like this is only used by the process record code, and furthermore only like: if (record_full_arch_list_add_mem (rsp, AMD64_LINUX_redzone + AMD64_LINUX_xstate + AMD64_LINUX_frame_size)) return -1; These are defined as: #define AMD64_LINUX_redzone 128 #define AMD64_LINUX_xstate 512 #define AMD64_LINUX_frame_size 560 which adds up to 1200, which maybe is also wrong (dunno), but at least is larger and maybe (also dunno) harmless in this context. Tom