From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 14179 invoked by alias); 13 Jun 2016 15:55:35 -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 14164 invoked by uid 89); 13 Jun 2016 15:55:34 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-3.3 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS autolearn=ham version=3.3.2 spammy=meaningful, Hx-languages-length:3585 X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Mon, 13 Jun 2016 15:55:32 +0000 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 522FEC00C91F; Mon, 13 Jun 2016 15:55:31 +0000 (UTC) Received: from [127.0.0.1] (ovpn01.gateway.prod.ext.ams2.redhat.com [10.39.146.11]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u5DFtTX7014142; Mon, 13 Jun 2016 11:55:30 -0400 Subject: Re: [PATCH 11/12] Use reinsert_breakpoint for vCont;s To: Yao Qi , gdb-patches@sourceware.org References: <1464859846-15619-1-git-send-email-yao.qi@linaro.org> <1464859846-15619-12-git-send-email-yao.qi@linaro.org> From: Pedro Alves Message-ID: <61835b69-a4bf-a912-4eb3-b223c2a16614@redhat.com> Date: Mon, 13 Jun 2016 15:55:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.1.0 MIME-Version: 1.0 In-Reply-To: <1464859846-15619-12-git-send-email-yao.qi@linaro.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-SW-Source: 2016-06/txt/msg00242.txt.bz2 On 06/02/2016 10:30 AM, Yao Qi wrote: > @@ -4293,7 +4313,7 @@ linux_resume_one_lwp_throw (struct lwp_info *lwp, > > step = maybe_hw_step (thread); > } > - else > + else if (lwp->resume != NULL && lwp->resume->kind != resume_step) > { > /* If the thread isn't doing step-over, there shouldn't be any > reinsert breakpoints. */ Consider (non-stop RSP): -> vCont;s:1 <- OK -> vCont;s:2 <- OK The handling of the second vCont sets thread 1's lwp->resume to NULL. The lwp->resume pointer is only meaningful within linux_resume and its callees. (But this function is called in other contexts.) > @@ -5009,12 +5033,52 @@ linux_resume (struct thread_resume *resume_info, size_t n) > debug_printf ("Resuming, no pending status or step over needed\n"); > } > > + /* Before we resume the threads, if resume_step is requested by GDB, > + stop all threads and install reinsert breakpoints. */ Looking again, I think the rationale for stopping threads should be mentioned here, as it's not obvious. > + if (!leave_all_stopped && can_software_single_step ()) > + { > + struct inferior_list_entry *inf, *tmp; > + > + if (debug_threads) > + debug_printf ("Handle resume_step.\n"); > + > + ALL_INFERIORS (&all_threads, inf, tmp) > + { > + struct thread_info *thread = (struct thread_info *) inf; > + struct lwp_info *lwp = get_thread_lwp (thread); > + > + if (lwp->resume != NULL && lwp->resume->kind == resume_step) > + { > + if (!resume_step_is_handled) > + { > + stop_all_lwps (0, NULL); > + > + if (debug_threads) > + debug_printf ("Done stopping all threads.\n"); > + > + resume_step_is_handled = 1; > + } > + > + install_software_single_step_breakpoints (lwp); > + > + if (debug_threads) > + debug_printf ("Insert breakpoint for resume_step LWP %ld\n", > + lwpid_of (thread)); > + } > + } > + > + if (debug_threads) > + debug_printf ("Handle resume_step. Done\n"); > + } > + > /* Even if we're leaving threads stopped, queue all signals we'd > otherwise deliver. */ > find_inferior (&all_threads, linux_resume_one_thread, &leave_all_stopped); > > if (need_step_over) > start_step_over (get_thread_lwp (need_step_over)); > + else if (resume_step_is_handled) > + unstop_all_lwps (0, NULL); > > if (debug_threads) > { > @@ -5110,7 +5174,8 @@ proceed_one_lwp (struct inferior_list_entry *entry, void *except) > if (debug_threads) > debug_printf (" stepping LWP %ld, client wants it stepping\n", > lwpid_of (thread)); > - step = 1; > + > + step = maybe_hw_step (thread); > } > else if (lwp->bp_reinsert != 0) > { > @@ -5176,6 +5241,30 @@ proceed_all_lwps (void) > if (debug_threads) > debug_printf ("Proceeding, no step-over needed\n"); > > + /* Re-install the reinsert breakpoints on software single step target > + if the client wants it step. */ > + if (can_software_single_step ()) Not immediately obvious to why is this necessary. Where were they removed in the first place? I'm it must be necessary, but maybe extending the comment helps. > + { > + struct inferior_list_entry *inf, *tmp; > + > + ALL_INFERIORS (&all_threads, inf, tmp) > + { > + struct thread_info *thread = (struct thread_info *) inf; > + > + if (thread->last_resume_kind == resume_step) > + { > + struct lwp_info *lwp = get_thread_lwp (thread); > + > + if (!has_reinsert_breakpoints (thread)) > + install_software_single_step_breakpoints (lwp); > + > + if (debug_threads) > + debug_printf ("Insert breakpoint for resume_step LWP %ld\n", > + lwpid_of (thread)); > + } > + } > + } > + > find_inferior (&all_threads, proceed_one_lwp, NULL); > } Thanks, Pedro Alves