From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 104415 invoked by alias); 24 Feb 2016 18:55:52 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 104402 invoked by uid 89); 24 Feb 2016 18:55:51 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-0.9 required=5.0 tests=BAYES_00,KAM_LAZY_DOMAIN_SECURITY autolearn=no version=3.3.2 spammy=agent, HContent-Transfer-Encoding:8bit X-HELO: usplmg21.ericsson.net Received: from usplmg21.ericsson.net (HELO usplmg21.ericsson.net) (198.24.6.65) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-SHA encrypted) ESMTPS; Wed, 24 Feb 2016 18:55:50 +0000 Received: from EUSAAHC008.ericsson.se (Unknown_Domain [147.117.188.96]) by usplmg21.ericsson.net (Symantec Mail Security) with SMTP id 91.87.32102.A9CFDC65; Wed, 24 Feb 2016 19:55:22 +0100 (CET) Received: from elxa4wqvvz1 (147.117.188.8) by smtps-am.internal.ericsson.com (147.117.188.96) with Microsoft SMTP Server (TLS) id 14.3.248.2; Wed, 24 Feb 2016 13:55:46 -0500 References: <1455910116-13237-1-git-send-email-antoine.tremblay@ericsson.com> <56C7796B.3030504@redhat.com> <56CDF23A.8000007@redhat.com> <56CDF48B.5040008@0x04.net> <56CDF792.3040604@redhat.com> User-agent: mu4e 0.9.17; emacs 24.4.1 From: Antoine Tremblay To: Pedro Alves CC: Marcin =?utf-8?Q?Ko=C5=9Bcielnicki?= , "Antoine Tremblay" , , Subject: Re: [PATCH v3] Enable tracing of pseudo-registers on ARM In-Reply-To: <56CDF792.3040604@redhat.com> Date: Wed, 24 Feb 2016 18:55:00 -0000 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit X-IsSubscribed: yes X-SW-Source: 2016-02/txt/msg00749.txt.bz2 Pedro Alves writes: > On 02/24/2016 06:20 PM, Marcin Kościelnicki wrote: >> On 24/02/16 19:11, Pedro Alves wrote: >>> On 02/22/2016 04:51 PM, Antoine Tremblay wrote: >>>> > >>>> While looking at fixing this for all the archs involved it would be >>>> much simpler to test if gdbserver would make use of it. >>>> >>>> As it is now, I'm concerned that calling gdbarch_remote_register_number >>>> in ax_reg, ax_mask_reg could break things if the arch already considers >>>> the gdb raw -> target raw mapping like s390 and x86 do already (I'm not >>>> 100% sure the mapping is already ok)? >>> >>> WDTM? Where do they do this already? >> >> FWIW, I failed to look at the numbering used when I wrote the x86 and >> s390 ax functions, so they're most likely wrong (I just copied the >> regnum computation logic from pseudo_read/write, which uses gdb >> numbers). s390 hasn't landed yet, so it's only x86 that you'd have to >> fix now (and mips, I think, but that doesn't support tracepoints yet...). > > I don't think there's anything that needs fixing in the i386 implementation. > > The x86 implementation maps gdb pseudo register numbers to whatever > raw gdb registers back the former up, like: > > ax_reg_mask (ax, I387_FSTAT_REGNUM (tdep)); > > That OK. > > The trouble is that in the end we send gdb numbers to the target in the > ax, instead of tdesc/remote numbers. > > We never noticed because gdbserver always collects all raw registers > anyway. > > Seems to me that the fix is to make ax_reg / ax_reg_mask take gdb raw > numbers as input (as it does today), and then make it map those to > tdesc/remote number just before it puts the reg number in the agent > expression bytecode / reg mask. And that covers all archs. > >> >> Testing this is possible if you write some conditions that involve >> reading pseudo-registers (since ax_pseudo_register_push_stack will be >> called), the problem is that I only implemented >> ax_pseudo_register_collect for x86... >> >> Are you going to make some higher-level patch that will magically fix it >> for my s390 patch, or do I have to fix that on my own? > > I haven't memorized your s390 patch :-) but there's probably nothing to > do on the s390-specific bits. > The only requirement for this to work properly is that the arch uses tdesc_use_registers, otherwise the default mapping function to tdesc is identity to GDB numbers. s390 uses that so it should be fine. Thanks, Antoine