From patchwork Thu May 28 22:12:34 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Don Breazeal X-Patchwork-Id: 6971 Received: (qmail 65005 invoked by alias); 28 May 2015 22:13:01 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Delivered-To: mailing list gdb-patches@sourceware.org Received: (qmail 64923 invoked by uid 89); 28 May 2015 22:13:00 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.2 required=5.0 tests=AWL, BAYES_00, RCVD_IN_DNSWL_LOW, SPF_PASS autolearn=ham version=3.3.2 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, 28 May 2015 22:12:58 +0000 Received: from svr-orw-fem-02x.mgc.mentorg.com ([147.34.96.206] helo=SVR-ORW-FEM-02.mgc.mentorg.com) by relay1.mentorg.com with esmtp id 1Yy62p-0005fu-8o from Don_Breazeal@mentor.com for gdb-patches@sourceware.org; Thu, 28 May 2015 15:12:55 -0700 Received: from build4-lucid-cs (147.34.91.1) by svr-orw-fem-02.mgc.mentorg.com (147.34.96.168) with Microsoft SMTP Server id 14.3.224.2; Thu, 28 May 2015 15:12:54 -0700 Received: by build4-lucid-cs (Postfix, from userid 1905) id C1D0440F6C; Thu, 28 May 2015 15:12:54 -0700 (PDT) From: Don Breazeal To: Subject: [commit][PATCH 2/3] Initialize last_resume_kind for remote fork child Date: Thu, 28 May 2015 15:12:34 -0700 Message-ID: <1432851155-24563-2-git-send-email-donb@codesourcery.com> In-Reply-To: <1432851155-24563-1-git-send-email-donb@codesourcery.com> References: <1432851155-24563-1-git-send-email-donb@codesourcery.com> MIME-Version: 1.0 X-IsSubscribed: yes This patch fixes some intermittent test failures in gdb.base/foll-vfork.exp where a vfork child would be (incorrectly) resumed when handling the vfork event. In this case the result was a subsequent event reported to the client side as a SIGTRAP delivered to the as-yet-unknown child thread. The new thread was resumed (incorrectly) in linux-low.c when resume_stopped_resumed_lwps was called from linux_wait_for_event_filtered after the vfork event had been handled in handle_extended_wait. Gdbserver/linux-low.c's add_thread function creates threads with last_resume_kind == resume_continue by default. This field is used by resume_stopped_resumed_lwps to decide whether to perform the resume: static void resume_stopped_resumed_lwps (struct inferior_list_entry *entry) { struct thread_info *thread = (struct thread_info *) entry; struct lwp_info *lp = get_thread_lwp (thread); if (lp->stopped && !lp->status_pending_p && thread->last_resume_kind != resume_stop && thread->last_status.kind == TARGET_WAITKIND_IGNORE) { So the fix is to make sure to set thread->last_resume_kind to resume_stop. Here we do that for new fork children in gdbserver/linux-low.c:handle_extended_wait. In addition, it seemed prudent to initialize lwp_info.status_pending_p for the new fork child. I also rearranged the initialization code so that all of the lwp_info initialization was together, rather than intermixed with thread_info and process_info initialization. Tested native, native-gdbserver, native-extended-gdbserver on x86_64 GNU/Linux. gdb/gdbserver/ * linux-low.c (handle_extended_wait): Initialize thread_info.last_resume_kind for new fork children. --- gdb/gdbserver/ChangeLog | 5 +++++ gdb/gdbserver/linux-low.c | 6 +++++- 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog index 0f30c66..4e4f429 100644 --- a/gdb/gdbserver/ChangeLog +++ b/gdb/gdbserver/ChangeLog @@ -1,3 +1,8 @@ +2015-05-28 Don Breazeal + + * linux-low.c (handle_extended_wait): Initialize + thread_info.last_resume_kind for new fork children. + 2015-05-15 Pedro Alves * target.h (target_handle_new_gdb_connection): Rewrite using if diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c index 9f3ea48..d763c66 100644 --- a/gdb/gdbserver/linux-low.c +++ b/gdb/gdbserver/linux-low.c @@ -457,6 +457,7 @@ handle_extended_wait (struct lwp_info *event_lwp, int wstat) struct process_info *parent_proc; struct process_info *child_proc; struct lwp_info *child_lwp; + struct thread_info *child_thr; struct target_desc *tdesc; ptid = ptid_build (new_pid, new_pid, 0); @@ -479,6 +480,10 @@ handle_extended_wait (struct lwp_info *event_lwp, int wstat) child_lwp = add_lwp (ptid); gdb_assert (child_lwp != NULL); child_lwp->stopped = 1; + child_lwp->must_set_ptrace_flags = 1; + child_lwp->status_pending_p = 0; + child_thr = get_lwp_thread (child_lwp); + child_thr->last_resume_kind = resume_stop; parent_proc = get_thread_process (event_thr); child_proc->attached = parent_proc->attached; clone_all_breakpoints (&child_proc->breakpoints, @@ -488,7 +493,6 @@ handle_extended_wait (struct lwp_info *event_lwp, int wstat) tdesc = xmalloc (sizeof (struct target_desc)); copy_target_description (tdesc, parent_proc->tdesc); child_proc->tdesc = tdesc; - child_lwp->must_set_ptrace_flags = 1; /* Clone arch-specific process data. */ if (the_low_target.new_fork != NULL)