From patchwork Mon Dec 12 20:31:01 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pedro Alves X-Patchwork-Id: 61851 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 9A16F383AB4A for ; Mon, 12 Dec 2022 20:34:45 +0000 (GMT) X-Original-To: gdb-patches@sourceware.org Delivered-To: gdb-patches@sourceware.org Received: from mail-wm1-f46.google.com (mail-wm1-f46.google.com [209.85.128.46]) by sourceware.org (Postfix) with ESMTPS id 198C03864A1F for ; Mon, 12 Dec 2022 20:31:41 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 198C03864A1F Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=palves.net Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-wm1-f46.google.com with SMTP id v7so6633111wmn.0 for ; Mon, 12 Dec 2022 12:31:41 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=xg5gDJDCSh6EgXpnu0EC3fJzKJE2l5y7qreUqcVn9PU=; b=6oPdm/4H1h0/FgnWJ76+r+E2R6ZHBG1/TJIcLt/nToESwwMWiHBO3AvTAqn+LkCkqH hQlZHNVprOl/FMUa+w/jMFaR9yPmkgwBFX0lQlSnDcASCxj90Mh8z0Ib/UsMuTGHsErB NW9JvS2KiJoQcAtLyZX+5x0ULsNzyezDsgRESaLLi1P7JOqs0szey3KIphKfXvGuVLlq 6+HmoFQV2oQyD+rNPeZZmzSbpozw2W2nhX0C4m7aRAlOZRZrKqLerbSj66EDHcrQsLsu H98Xb1ZQxx1JW1z2Lm2V9kefR91UqhulBhe6yjhMOCzYtyuuB7Fpn2bUggawhxM4VSOa GmlQ== X-Gm-Message-State: ANoB5pkKF0bWRF4NuKdAfTXPYT2rGwfGM25vS1vm46+6qXWA105J3bhq Pf+o3vuIYcMof+EoYuUsfoigqvfECgfbDA== X-Google-Smtp-Source: AA0mqf5ptEzjNj8Q2puWKolNsuz3O4xE1T2aEgMGhsNXY6bu4tDLOExS2AoAzrN38l2QDiMQcuSqVw== X-Received: by 2002:a05:600c:3647:b0:3cf:5014:c773 with SMTP id y7-20020a05600c364700b003cf5014c773mr13245209wmq.40.1670877100455; Mon, 12 Dec 2022 12:31:40 -0800 (PST) Received: from localhost ([2001:8a0:f912:6700:afd9:8b6d:223f:6170]) by smtp.gmail.com with ESMTPSA id m127-20020a1c2685000000b003d1d5a83b2esm10423315wmm.35.2022.12.12.12.31.40 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 12 Dec 2022 12:31:40 -0800 (PST) From: Pedro Alves To: gdb-patches@sourceware.org Subject: [PATCH 31/31] Cancel execution command on thread exit, when stepping, nexting, etc. Date: Mon, 12 Dec 2022 20:31:01 +0000 Message-Id: <20221212203101.1034916-32-pedro@palves.net> X-Mailer: git-send-email 2.36.0 In-Reply-To: <20221212203101.1034916-1-pedro@palves.net> References: <20221212203101.1034916-1-pedro@palves.net> MIME-Version: 1.0 X-Spam-Status: No, score=-10.5 required=5.0 tests=BAYES_00, FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM, GIT_PATCH_0, HEADER_FROM_DIFFERENT_DOMAINS, KAM_DMARC_STATUS, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: gdb-patches-bounces+patchwork=sourceware.org@sourceware.org Sender: "Gdb-patches" If your target has no support for TARGET_WAITKIND_NO_RESUMED events (and no way to support them, such as the yet-unsubmitted AMDGPU target), and you step over thread exit with scheduler-locking on, this is what you get: (gdb) n [Thread ... exited] *hang* Getting back the prompt by typing Ctrl-C may not even work, since no inferior thread is running to receive the SIGINT. Even if it works, it seems unnecessarily harsh. If you started an execution command for which there's a clear thread of interest (step, next, until, etc.), and that thread disappears, then I think it's more user friendly if GDB just detects the situation and aborts the command, giving back the prompt. That is what this commit implements. It does this by explicitly requesting the target to report thread exit events whenever the main resumed thread has a thread_fsm. Note that unlike stepping over a breakpoint, we don't need to enable clone events in this case. With this patch, we get: (gdb) n [Thread 0x7ffff7d89700 (LWP 3961883) exited] Command aborted, thread exited. (gdb) Change-Id: I901ab64c91d10830590b2dac217b5264635a2b95 Reviewed-By: Andrew Burgess --- gdb/infrun.c | 73 ++++++++++++++--- .../gdb.threads/step-over-thread-exit.exp | 79 ++++++++++++------- 2 files changed, 115 insertions(+), 37 deletions(-) diff --git a/gdb/infrun.c b/gdb/infrun.c index 21e5aa0f50e..61d2a14c646 100644 --- a/gdb/infrun.c +++ b/gdb/infrun.c @@ -1886,6 +1886,22 @@ displaced_step_prepare (thread_info *thread) return status; } +/* True if any thread of TARGET that matches RESUME_PTID requires + target_thread_events enabled. This assumes TARGET does not support + target thread options. */ + +static bool +any_thread_needs_target_thread_events (process_stratum_target *target, + ptid_t resume_ptid) +{ + for (thread_info *tp : all_non_exited_threads (target, resume_ptid)) + if (displaced_step_in_progress_thread (tp) + || schedlock_applies (tp) + || tp->thread_fsm () != nullptr) + return true; + return false; +} + /* Maybe disable thread-{cloned,created,exited} event reporting after a step-over (either in-line or displaced) finishes. */ @@ -1909,9 +1925,10 @@ update_thread_events_after_step_over (thread_info *event_thread, else { /* We can only control the target-wide target_thread_events - setting. Disable it, but only if other threads don't need it - enabled. */ - if (!displaced_step_in_progress_any_thread ()) + setting. Disable it, but only if other threads in the target + don't need it enabled. */ + process_stratum_target *target = event_thread->inf->process_target (); + if (!any_thread_needs_target_thread_events (target, minus_one_ptid)) target_thread_events (false); } } @@ -2488,12 +2505,25 @@ do_target_resume (ptid_t resume_ptid, bool step, enum gdb_signal sig) else target_thread_events (true); } + else if (tp->thread_fsm () != nullptr) + { + gdb_thread_options options = GDB_THREAD_OPTION_EXIT; + if (target_supports_set_thread_options (options)) + tp->set_thread_options (options); + else + target_thread_events (true); + } else { if (target_supports_set_thread_options (0)) tp->set_thread_options (0); - else if (!displaced_step_in_progress_any_thread ()) - target_thread_events (false); + else + { + process_stratum_target *resume_target = tp->inf->process_target (); + if (!any_thread_needs_target_thread_events (resume_target, + resume_ptid)) + target_thread_events (false); + } } /* If we're resuming more than one thread simultaneously, then any @@ -5671,6 +5701,13 @@ handle_thread_exited (execution_control_state *ecs) ecs->event_thread->stepping_over_breakpoint = 0; ecs->event_thread->stepping_over_watchpoint = 0; + /* If the thread had an FSM, then abort the command. But only after + finishing the step over, as in non-stop mode, aborting this + thread's command should not interfere with other threads. We + must check this before finish_step over, however, which may + update the thread list and delete the event thread. */ + bool abort_cmd = (ecs->event_thread->thread_fsm () != nullptr); + /* Maybe the thread was doing a step-over, if so release resources and start any further pending step-overs. @@ -5684,6 +5721,13 @@ handle_thread_exited (execution_control_state *ecs) the event thread has exited. */ gdb_assert (ret == 0); + if (abort_cmd) + { + delete_thread (ecs->event_thread); + ecs->event_thread = nullptr; + return false; + } + /* If finish_step_over started a new in-line step-over, don't try to restart anything else. */ if (step_over_info_valid_p ()) @@ -9062,7 +9106,8 @@ normal_stop (void) if (inferior_ptid != null_ptid) finish_ptid = ptid_t (inferior_ptid.pid ()); } - else if (last.kind () != TARGET_WAITKIND_NO_RESUMED) + else if (last.kind () != TARGET_WAITKIND_NO_RESUMED + && last.kind () != TARGET_WAITKIND_THREAD_EXITED) finish_ptid = inferior_ptid; gdb::optional maybe_finish_thread_state; @@ -9105,7 +9150,8 @@ normal_stop (void) { if ((last.kind () != TARGET_WAITKIND_SIGNALLED && last.kind () != TARGET_WAITKIND_EXITED - && last.kind () != TARGET_WAITKIND_NO_RESUMED) + && last.kind () != TARGET_WAITKIND_NO_RESUMED + && last.kind () != TARGET_WAITKIND_THREAD_EXITED) && target_has_execution () && previous_thread != inferior_thread ()) { @@ -9121,7 +9167,8 @@ normal_stop (void) update_previous_thread (); } - if (last.kind () == TARGET_WAITKIND_NO_RESUMED) + if (last.kind () == TARGET_WAITKIND_NO_RESUMED + || last.kind () == TARGET_WAITKIND_THREAD_EXITED) { stop_print_frame = false; @@ -9129,7 +9176,12 @@ normal_stop (void) if (current_ui->prompt_state == PROMPT_BLOCKED) { target_terminal::ours_for_output (); - gdb_printf (_("No unwaited-for children left.\n")); + if (last.kind () == TARGET_WAITKIND_NO_RESUMED) + gdb_printf (_("No unwaited-for children left.\n")); + else if (last.kind () == TARGET_WAITKIND_THREAD_EXITED) + gdb_printf (_("Command aborted, thread exited.\n")); + else + gdb_assert_not_reached ("unhandled"); } } @@ -9214,7 +9266,8 @@ normal_stop (void) { if (last.kind () != TARGET_WAITKIND_SIGNALLED && last.kind () != TARGET_WAITKIND_EXITED - && last.kind () != TARGET_WAITKIND_NO_RESUMED) + && last.kind () != TARGET_WAITKIND_NO_RESUMED + && last.kind () != TARGET_WAITKIND_THREAD_EXITED) /* Delete the breakpoint we stopped at, if it wants to be deleted. Delete any breakpoint that is to be deleted at the next stop. */ breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat); diff --git a/gdb/testsuite/gdb.threads/step-over-thread-exit.exp b/gdb/testsuite/gdb.threads/step-over-thread-exit.exp index ed8534cf518..a0056740478 100644 --- a/gdb/testsuite/gdb.threads/step-over-thread-exit.exp +++ b/gdb/testsuite/gdb.threads/step-over-thread-exit.exp @@ -29,7 +29,7 @@ if { [build_executable "failed to prepare" $testfile \ # NS_STOP_ALL is only used if testing "set non-stop on", and indicates # whether to have GDB explicitly stop all threads before continuing to # thread exit. -proc test {displaced-stepping non-stop target-non-stop schedlock ns_stop_all} { +proc test {displaced-stepping non-stop target-non-stop schedlock cmd ns_stop_all} { if {${non-stop} == "off" && $ns_stop_all} { error "invalid arguments" } @@ -72,31 +72,54 @@ proc test {displaced-stepping non-stop target-non-stop schedlock ns_stop_all} { gdb_test_no_output "set scheduler-locking ${schedlock}" - gdb_test "continue" \ - "No unwaited-for children left." \ - "continue stops when thread exits" + if {$cmd == "continue"} { + gdb_test "continue" \ + "No unwaited-for children left." \ + "continue stops when thread exits" + } else { + gdb_test $cmd \ + "Command aborted, thread exited\\." \ + "command aborts when thread exits" + } } else { gdb_test_no_output "set scheduler-locking ${schedlock}" - for { set i 0 } { $i < 100 } { incr i } { - with_test_prefix "iter $i" { - set ok 0 - set thread "" - gdb_test_multiple "continue" "" { - -re -wrap "Thread ($::decimal) .*hit Breakpoint $::decimal.* my_exit_syscall .*" { - set thread $expect_out(1,string) - set ok 1 - } - } - if {!${ok}} { - # Exit if there's a failure to avoid lengthy - # timeouts. - break + if {$cmd != "continue"} { + set thread "" + gdb_test_multiple "continue" "" { + -re -wrap "Thread ($::decimal) .*hit Breakpoint $::decimal.* my_exit_syscall .*" { + set thread $expect_out(1,string) } + } + if {${non-stop}} { + gdb_test -nopass "thread $thread" "Switching to thread .*" \ + "switch to event thread" + } - if {${non-stop}} { - gdb_test "thread $thread" "Switching to thread .*" \ - "switch to event thread" + gdb_test $cmd \ + "Command aborted, thread exited\\." \ + "command aborts when thread exits" + } else { + for { set i 0 } { $i < 100 } { incr i } { + with_test_prefix "iter $i" { + set ok 0 + set thread "" + gdb_test_multiple "continue" "" { + -re -wrap "Thread ($::decimal) .*hit Breakpoint $::decimal.* my_exit_syscall .*" { + set thread $expect_out(1,string) + set ok 1 + } + } + if {!${ok}} { + # Exit if there's a failure to avoid lengthy + # timeouts. + break + } + + if {${non-stop}} { + gdb_test -nopass "thread $thread" "Switching to thread .*" \ + "switch to event thread" + } } } } @@ -112,13 +135,15 @@ foreach_with_prefix displaced-stepping {off auto} { } foreach_with_prefix schedlock {off on} { - if {${non-stop} == "on"} { - foreach_with_prefix ns_stop_all {0 1} { - test ${displaced-stepping} ${non-stop} ${target-non-stop} \ - ${schedlock} ${ns_stop_all} + foreach_with_prefix cmd {"next" "continue"} { + if {${non-stop} == "on"} { + foreach_with_prefix ns_stop_all {0 1} { + test ${displaced-stepping} ${non-stop} ${target-non-stop} \ + ${schedlock} ${cmd} ${ns_stop_all} + } + } else { + test ${displaced-stepping} ${non-stop} ${target-non-stop} ${schedlock} ${cmd} 0 } - } else { - test ${displaced-stepping} ${non-stop} ${target-non-stop} ${schedlock} 0 } } }