From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 101697 invoked by alias); 1 Feb 2016 19:26:34 -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 101685 invoked by uid 89); 1 Feb 2016 19:26:33 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.4 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS autolearn=ham version=3.3.2 spammy=847, PRMS, prms, sk:displac 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, 01 Feb 2016 19:26:31 +0000 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) by mx1.redhat.com (Postfix) with ESMTPS id C66CCC0AA571; Mon, 1 Feb 2016 19:26:30 +0000 (UTC) Received: from [127.0.0.1] (ovpn01.gateway.prod.ext.phx2.redhat.com [10.5.9.1]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u11JQTPj017384; Mon, 1 Feb 2016 14:26:29 -0500 Message-ID: <56AFB165.8000808@redhat.com> Date: Mon, 01 Feb 2016 19:26:00 -0000 From: Pedro Alves User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Don Breazeal , gdb-patches@sourceware.org Subject: [pushed] Test gdb.threads/forking-threads-plus-breakpoint.exp with, displaced stepping off (Re: [PATCH 1/3] PR remote/19496, internal err forking-threads-plus-bkpt) References: <1453942111-1215-1-git-send-email-donb@codesourcery.com> <1453942111-1215-2-git-send-email-donb@codesourcery.com> In-Reply-To: <1453942111-1215-2-git-send-email-donb@codesourcery.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-SW-Source: 2016-02/txt/msg00016.txt.bz2 On 01/28/2016 12:48 AM, Don Breazeal wrote: > The cause of the problem was the following sequence of events: > > * GDB knows only about the main thread > > * the first fork event is reported to GDB, saved as pending_event > > * qXfer:threads_read gets the threads from the remote. > remove_new_fork_children id's the fork child from the pending event > and removes it from the list reported to GDB. All the rest of the > threads, including the fork parent, are added to the GDB thread list. > > * GDB stops all the threads. All the stop events are pushed onto the > stop reply queue behind the pending fork event. As this is a non-stop test, if GDB is stopping all the threads, then it must be that your arch doesn't support displaced stepping (which is true). By forcing displaced stepping off, I see the same internal error on x86. I've pushed the testsuite change below to expose the problem. Haven't managed to look at your fix in detail yet. >From 6b2e4f10aeb64868720de06d3b2da3cc2d908f10 Mon Sep 17 00:00:00 2001 From: Pedro Alves Date: Mon, 1 Feb 2016 18:48:04 +0000 Subject: [PATCH] Test gdb.threads/forking-threads-plus-breakpoint.exp with displaced stepping off This exposes the internal error Don mentioned in PR19496: (1) internal error -- gdb/target.c:2713: internal-error: Can't determine the current address space of thread More analysis here: https://sourceware.org/ml/gdb-patches/2016-01/msg00685.html The (now kfailed) internal error looks like: continue & Continuing. (gdb) PASS: gdb.threads/forking-threads-plus-breakpoint.exp: cond_bp_target=1: detach_on_fork=on: displaced=off: continue & [New Thread 2846.2847] (...) [New Thread 2867.2867] /home/pedro/gdb/mygit/src/gdb/target.c:2723: internal-error: Can't determine the current address space of thread Thread 2846.2846 A problem internal to GDB has been detected, further debugging may prove unreliable. Quit this debugging session? (y or n) KFAIL: gdb.threads/forking-threads-plus-breakpoint.exp: cond_bp_target=1: detach_on_fork=on: displaced=off: inferior 1 exited (GDB internal error) (PRMS: remote/19496) Resyncing due to internal error. gdb/testsuite/ChangeLog: 2016-02-01 Pedro Alves PR remote/19496 * gdb.threads/forking-threads-plus-breakpoint.exp (displaced_stepping_supported): New global. (probe_displaced_stepping_support): New procedure. (do_test): Add 'displaced' parameter, and use it. (top level): Check for displaced stepping support. Add displaced stepping on/off testing axis. --- gdb/testsuite/ChangeLog | 9 ++++ .../forking-threads-plus-breakpoint.exp | 63 ++++++++++++++++++++-- 2 files changed, 67 insertions(+), 5 deletions(-) diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index 6af0e48..fb64674 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,12 @@ +2016-02-01 Pedro Alves + + * gdb.threads/forking-threads-plus-breakpoint.exp + (displaced_stepping_supported): New global. + (probe_displaced_stepping_support): New procedure. + (do_test): Add 'displaced' parameter, and use it. + (top level): Check for displaced stepping support. Add displaced + stepping on/off testing axis. + 2016-02-01 Andrew Burgess * gdb.mi/mi-vla-fortran.exp: Add XFAIL for accessing unassociated diff --git a/gdb/testsuite/gdb.threads/forking-threads-plus-breakpoint.exp b/gdb/testsuite/gdb.threads/forking-threads-plus-breakpoint.exp index b5f7c21..6c72061 100644 --- a/gdb/testsuite/gdb.threads/forking-threads-plus-breakpoint.exp +++ b/gdb/testsuite/gdb.threads/forking-threads-plus-breakpoint.exp @@ -24,13 +24,49 @@ if {[build_executable "failed to prepare" $testfile $srcfile {debug pthreads}] = return -1 } +# Assume yes. +set displaced_stepping_supported 1 + +# "set displaced on" only tells gdb to use displaced stepping if +# possible. Probe for actual support. + +proc probe_displaced_stepping_support {} { + global displaced_stepping_supported + global binfile gdb_prompt + + with_test_prefix "probe displaced-stepping support" { + clean_restart $binfile + + gdb_test_no_output "set displaced on" + if ![runto_main] then { + fail "Can't run to main" + return 0 + } + + # We're stopped at the main breakpoint. If displaced stepping is + # supported, we'll see related debug output while we step past + # that breakpoint. + gdb_test_no_output "set debug displaced 1" + gdb_test_multiple "next" "probe" { + -re "displaced pc to.*$gdb_prompt $" { + pass "supported" + } + -re ".*$gdb_prompt $" { + set displaced_stepping_supported 0 + pass "not supported" + } + } + } +} + # The test proper. If COND_BP_TARGET is true, then test with # conditional breakpoints evaluated on the target side, if possible. # DETACH_ON_FORK is used as value for the "set detach-on-fork" # setting. If "on", this exercises GDB explicitly continuing the fork # child until exit. If "off", this exercises GDB detaching the fork -# child. -proc do_test { cond_bp_target detach_on_fork } { +# child. DISPLACED indicates whether to use displaced stepping or +# not. +proc do_test { cond_bp_target detach_on_fork displaced } { global GDBFLAGS global srcfile testfile binfile global decimal gdb_prompt @@ -48,6 +84,7 @@ proc do_test { cond_bp_target detach_on_fork } { } gdb_test_no_output "set detach-on-fork $detach_on_fork" + gdb_test_no_output "set displaced $displaced" gdb_test "break $linenum if zero == 1" \ "Breakpoint .*" \ @@ -63,6 +100,12 @@ proc do_test { cond_bp_target detach_on_fork } { set fork_count 0 set ok 0 + if {$displaced == "off" + && [target_info exists gdb_protocol] + && ([target_info gdb_protocol] == "remote" + || [target_info gdb_protocol] == "extended-remote")} { + setup_kfail "remote/19496" *-*-* + } set test "inferior 1 exited" gdb_test_multiple "" $test { -re "Inferior 1 \(\[^\r\n\]+\) exited normally" { @@ -92,14 +135,24 @@ proc do_test { cond_bp_target detach_on_fork } { "only inferior 1 left" } +probe_displaced_stepping_support + foreach_with_prefix cond_bp_target {1 0} { foreach_with_prefix detach_on_fork {"on" "off"} { - do_test $cond_bp_target $detach_on_fork - # Disable "off" for now. The test does pass with # detach-on-fork off (at the time of writing), but gdb seems # to slow down quadratically as inferiors are created, and # then the test takes annoyingly long to complete... - break + if {$detach_on_fork == "off"} { + continue + } + + foreach_with_prefix displaced {"on" "off"} { + if {$displaced == "on" && !$displaced_stepping_supported} { + continue + } + + do_test $cond_bp_target $detach_on_fork $displaced + } } } -- 1.9.3