From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 1195 invoked by alias); 3 Mar 2016 18:20:33 -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 668 invoked by uid 89); 3 Mar 2016 18:20:32 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.8 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_NONE,SPF_PASS autolearn=ham version=3.3.2 spammy=pulling, Cause, hung, Our X-HELO: relay1.mentorg.com Received: from relay1.mentorg.com (HELO relay1.mentorg.com) (192.94.38.131) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Thu, 03 Mar 2016 18:20:31 +0000 Received: from svr-orw-fem-04.mgc.mentorg.com ([147.34.97.41]) by relay1.mentorg.com with esmtp id 1abXrQ-0006Q4-4R from Don_Breazeal@mentor.com ; Thu, 03 Mar 2016 10:20:28 -0800 Received: from [172.30.2.40] (147.34.91.1) by SVR-ORW-FEM-04.mgc.mentorg.com (147.34.97.41) with Microsoft SMTP Server (TLS) id 14.3.224.2; Thu, 3 Mar 2016 10:20:27 -0800 Subject: Re: [PING] Re: [PATCH v2 3/3] PR remote/19496, timeout in forking-threads-plus-bkpt To: , References: <1455150506-12760-1-git-send-email-donb@codesourcery.com> <56CF39FD.90502@codesourcery.com> From: Don Breazeal Message-ID: <56D8806A.1000505@codesourcery.com> Date: Thu, 03 Mar 2016 18:20:00 -0000 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <56CF39FD.90502@codesourcery.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-IsSubscribed: yes X-SW-Source: 2016-03/txt/msg00054.txt.bz2 Ping. I checked, the patch still applies cleanly to mainline. Thanks --Don On 2/25/2016 9:29 AM, Don Breazeal wrote: > Ping > Thanks, > --Don > > On 2/10/2016 4:28 PM, Don Breazeal wrote: >> On 2/1/2016 12:09 PM, Pedro Alves wrote: >>> On 02/01/2016 07:29 PM, Don Breazeal wrote: >>>> On 2/1/2016 4:05 AM, Pedro Alves wrote: >>> >>>> Hi Pedro, >> ---snip--- >>>> A fork event was reported to GDB before GDB knew about the parent thread, >>>> followed immediately by a breakpoint event in a different thread. The >>>> parent thread was subsequently added via remote_notice_new_inferior in >>>> process_stop_reply, but when the thread was added the thread_info.state >>>> was set to THREAD_STOPPED. The fork event was then handled correctly, >>>> but when the fork parent was resumed via a call to keep_going, the state >>>> was unchanged. >>> >>> Since this is non-stop, then it sounds to me like the bug is that the >>> thread should have been added in THREAD_RUNNING state. >>> >>> Consider that infrun may be pulling target events out of the target_ops >>> backend into its own event queue, but, not process them immediately. >>> >>> E.g., infrun may be stopping all threads temporarily for a step-over-breakpoint >>> operation for thread A (stop_all_threads). The waitstatus of all threads >>> is thus left pending in the thread structure (save_status), including the >>> fork event of thread B. Right at this point, if the user >>> does "info threads", that should show thread B (the fork parent) running, >>> not stopped, even if internally, gdb is holding it paused for a little bit. >>> >> >> Hi Pedro, >> Here is a new patch that adds the threads with the state set to >> THREAD_RUNNING for fork events. >> Thanks! >> --Don >> >> This patch addresses a failure in >> gdb.threads/forking-threads-plus-breakpoint.exp: >> >> FAIL: gdb.threads/forking-threads-plus-breakpoint.exp: cond_bp_target=1: >> detach_on_fork=on: inferior 1 exited (timeout) >> >> Cause: >> A fork event was reported to GDB before GDB knew about the parent thread, >> followed immediately by a breakpoint event in a different thread. The >> parent thread was subsequently added via remote_notice_new_inferior in >> process_stop_reply, but when the thread was added the thread_info.state >> was set to THREAD_STOPPED. The fork event was then handled correctly, >> but when the fork parent was resumed via a call to keep_going, the state >> was unchanged. >> >> The breakpoint event was then handled, which caused all the non-breakpoint >> threads to be stopped. When the breakpoint thread was resumed, all the >> non-breakpoint threads were resumed via infrun.c:restart_threads. Our old >> fork parent wasn't restarted, because it still had thread_info.state set to >> THREAD_STOPPED. Ultimately the program under debug hung waiting for a >> pthread_join while the old fork parent was stopped forever by GDB. >> >> Fix: >> Make sure to add the fork parent thread in the THREAD_RUNNING state by >> calling remote_notice_new_inferior with RUNNING set to 1 when processing >> a fork stop reply. >> >> Tested on x86_64 Linux and Nios II Linux target with x86 Linux host. >> >> gdb/ChangeLog: >> 2016-02-10 Don Breazeal >> >> * remote.c (process_stop_reply): Call remote_notice_new_inferior >> with RUNNING set to 1 when handling fork events. >> >> --- >> gdb/remote.c | 9 ++++++++- >> 1 file changed, 8 insertions(+), 1 deletion(-) >> >> diff --git a/gdb/remote.c b/gdb/remote.c >> index f09a06e..ab750a7 100644 >> --- a/gdb/remote.c >> +++ b/gdb/remote.c >> @@ -6818,7 +6818,14 @@ process_stop_reply (struct stop_reply *stop_reply, >> VEC_free (cached_reg_t, stop_reply->regcache); >> } >> >> - remote_notice_new_inferior (ptid, 0); >> + /* If a fork event arrived before we knew about the parent thread, >> + make sure to mark it as running when it is created. */ >> + if (status->kind == TARGET_WAITKIND_FORKED >> + || status->kind == TARGET_WAITKIND_VFORKED) >> + remote_notice_new_inferior (ptid, 1); >> + else >> + remote_notice_new_inferior (ptid, 0); >> + >> remote_thr = demand_private_info (ptid); >> remote_thr->core = stop_reply->core; >> remote_thr->stop_reason = stop_reply->stop_reason; >> >