From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 20171 invoked by alias); 17 Oct 2010 18:28:04 -0000 Received: (qmail 20162 invoked by uid 22791); 17 Oct 2010 18:28:02 -0000 X-SWARE-Spam-Status: No, hits=-6.1 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_HI,SPF_HELO_PASS,TW_TG,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Sun, 17 Oct 2010 18:27:57 +0000 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o9HIRmPA017176 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Sun, 17 Oct 2010 14:27:48 -0400 Received: from host1.dyn.jankratochvil.net (ovpn01.gateway.prod.ext.phx2.redhat.com [10.5.9.1]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id o9HIRkKK016739 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sun, 17 Oct 2010 14:27:48 -0400 Received: from host1.dyn.jankratochvil.net (localhost [127.0.0.1]) by host1.dyn.jankratochvil.net (8.14.4/8.14.4) with ESMTP id o9HIRkZc016345; Sun, 17 Oct 2010 20:27:46 +0200 Received: (from jkratoch@localhost) by host1.dyn.jankratochvil.net (8.14.4/8.14.4/Submit) id o9HIRjai016344; Sun, 17 Oct 2010 20:27:45 +0200 Date: Sun, 17 Oct 2010 18:28:00 -0000 From: Jan Kratochvil To: Pedro Alves Cc: gdb-patches@sourceware.org Subject: Re: [rfc] linux-nat: Never PTRACE_CONT a stepping thread Message-ID: <20101017182745.GA9936@host1.dyn.jankratochvil.net> References: <20100921234325.GA31267@host1.dyn.jankratochvil.net> <201010161809.53308.pedro@codesourcery.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201010161809.53308.pedro@codesourcery.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-IsSubscribed: yes 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 X-SW-Source: 2010-10/txt/msg00275.txt.bz2 On Sat, 16 Oct 2010 19:09:52 +0200, Pedro Alves wrote: > This patch alone on top of current mainline fixes the sigstep-threads.exp > test from . > Maybe check that test in along with this patch? OK, yes, I will recheck that patch on top of this one. > The corresponding remote.c patch (pasted below) that translates this > into a vCont with three actions (e.g., "vCont;C1e:795a;s:7959;c") also > fixes that test for gdbserver linux. Included it. > It'd be much cleaner to make the target_resume interface similar > to gdbserver's target_ops->resume interface (pass in a list of > resume actions, similar to vCont), but that shouldn't be a > prerequisite. Maybe someday... I agree that interface is better. Not a scope of this patch, though. Checked-in. Thanks for the review. Jan http://sourceware.org/ml/gdb-cvs/2010-10/msg00102.html --- src/gdb/ChangeLog 2010/10/17 17:45:16 1.12266 +++ src/gdb/ChangeLog 2010/10/17 18:24:46 1.12267 @@ -1,4 +1,19 @@ 2010-10-17 Jan Kratochvil + Pedro Alves + + * gdbthread.h (currently_stepping): New declaration. + * infrun.c (currently_stepping): Remove the forward declaration. + (currently_stepping): Make it global. + * linux-nat.c (resume_callback) stopped && lp->status == 0>: New + variables tp and step, initialized them. Pass STEP to to_resume. + Print also possibly "PTRACE_SINGLESTEP" if STEP. Initialize LP->STEP. + * remote.c (currently_stepping_callback): New. + (remote_vcont_resume) + : + New variable tp. Call currently_stepping_callback and step such + thread. + +2010-10-17 Jan Kratochvil * infrun.c (follow_exec): Replace symbol_file_add_main by symbol_file_add with SYMFILE_DEFER_BP_RESET, set_initial_language and --- src/gdb/gdbthread.h 2010/01/12 21:40:24 1.54 +++ src/gdb/gdbthread.h 2010/10/17 18:24:47 1.55 @@ -352,4 +352,6 @@ extern void update_thread_list (void); +extern int currently_stepping (struct thread_info *tp); + #endif /* GDBTHREAD_H */ --- src/gdb/infrun.c 2010/10/17 17:45:16 1.452 +++ src/gdb/infrun.c 2010/10/17 18:24:47 1.453 @@ -74,8 +74,6 @@ static void set_schedlock_func (char *args, int from_tty, struct cmd_list_element *c); -static int currently_stepping (struct thread_info *tp); - static int currently_stepping_or_nexting_callback (struct thread_info *tp, void *data); @@ -4851,7 +4849,7 @@ /* Is thread TP in the middle of single-stepping? */ -static int +int currently_stepping (struct thread_info *tp) { return ((tp->step_range_end && tp->step_resume_breakpoint == NULL) --- src/gdb/linux-nat.c 2010/09/06 13:59:02 1.184 +++ src/gdb/linux-nat.c 2010/10/17 18:24:47 1.185 @@ -1820,20 +1820,26 @@ } else if (lp->stopped && lp->status == 0) { + struct thread_info *tp = find_thread_ptid (lp->ptid); + /* lp->step may already contain a stale value. */ + int step = tp ? currently_stepping (tp) : 0; + if (debug_linux_nat) fprintf_unfiltered (gdb_stdlog, - "RC: PTRACE_CONT %s, 0, 0 (resuming sibling)\n", + "RC: %s %s, 0, 0 (resuming sibling)\n", + step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", target_pid_to_str (lp->ptid)); linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), - 0, TARGET_SIGNAL_0); + step, TARGET_SIGNAL_0); if (debug_linux_nat) fprintf_unfiltered (gdb_stdlog, - "RC: PTRACE_CONT %s, 0, 0 (resume sibling)\n", + "RC: %s %s, 0, 0 (resume sibling)\n", + step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", target_pid_to_str (lp->ptid)); lp->stopped = 0; - lp->step = 0; + lp->step = step; memset (&lp->siginfo, 0, sizeof (lp->siginfo)); lp->stopped_by_watchpoint = 0; } --- src/gdb/remote.c 2010/07/28 20:20:26 1.421 +++ src/gdb/remote.c 2010/10/17 18:24:47 1.422 @@ -4416,6 +4416,12 @@ return p; } +static int +currently_stepping_callback (struct thread_info *tp, void *data) +{ + return currently_stepping (tp); +} + /* Resume the remote inferior by using a "vCont" packet. The thread to be resumed is PTID; STEP and SIGGNAL indicate whether the resumed thread should be single-stepped and/or signalled. If PTID @@ -4458,6 +4464,8 @@ } else if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid)) { + struct thread_info *tp; + /* Resume all threads (of all processes, or of a single process), with preference for INFERIOR_PTID. This assumes inferior_ptid belongs to the set of all threads we are about @@ -4468,6 +4476,12 @@ p = append_resumption (p, endp, inferior_ptid, step, siggnal); } + tp = iterate_over_threads (currently_stepping_callback, NULL); + if (tp && !ptid_equal (tp->ptid, inferior_ptid)) + { + p = append_resumption (p, endp, tp->ptid, 1, TARGET_SIGNAL_0); + } + /* And continue others without a signal. */ p = append_resumption (p, endp, ptid, /*step=*/ 0, TARGET_SIGNAL_0); } --- src/gdb/testsuite/ChangeLog 2010/10/17 17:45:17 1.2482 +++ src/gdb/testsuite/ChangeLog 2010/10/17 18:24:47 1.2483 @@ -1,5 +1,10 @@ 2010-10-17 Jan Kratochvil + * gdb.threads/sigstep-threads.exp: New file. + * gdb.threads/sigstep-threads.c: New file. + +2010-10-17 Jan Kratochvil + * gdb.base/pie-execl.exp: New file. * gdb.base/pie-execl.c: New file. --- src/gdb/testsuite/gdb.threads/sigstep-threads.c +++ src/gdb/testsuite/gdb.threads/sigstep-threads.c 2010-10-17 18:24:59.596239000 +0000 @@ -0,0 +1,54 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2010 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . */ + +#include +#include +#include + +#include +#include +#define tgkill(tgid, tid, sig) syscall (__NR_tgkill, (tgid), (tid), (sig)) +#define gettid() syscall (__NR_gettid) + +static volatile int var; + +static void +handler (int signo) /* step-0 */ +{ /* step-0 */ + var++; /* step-1 */ + tgkill (getpid (), gettid (), SIGUSR1); /* step-2 */ +} + +static void * +start (void *arg) +{ + signal (SIGUSR1, handler); + tgkill (getpid (), gettid (), SIGUSR1); + assert (0); + + return NULL; +} + +int +main (void) +{ + pthread_t thread; + + pthread_create (&thread, NULL, start, NULL); + start (NULL); /* main-start */ + return 0; +} --- src/gdb/testsuite/gdb.threads/sigstep-threads.exp +++ src/gdb/testsuite/gdb.threads/sigstep-threads.exp 2010-10-17 18:24:59.896865000 +0000 @@ -0,0 +1,74 @@ +# Copyright 2010 Free Software Foundation, Inc. + +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 3 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . + +set testfile sigstep-threads +set srcfile ${testfile}.c +set executable ${testfile} +set binfile ${objdir}/${subdir}/${executable} + +if { [gdb_compile_pthreads "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug}] != "" } { + untested ${testfile}.exp + return -1 +} + +clean_restart $executable + +if ![runto_main] { + return -1; +} + +# `noprint' would not test the full logic of GDB. +gdb_test "handle SIGUSR1 nostop print pass" "\r\nSIGUSR1\[ \t\]+No\[ \t\]+Yes\[ \t\]+Yes\[ \t\].*" + +gdb_test_no_output "set scheduler-locking off" + +gdb_breakpoint [gdb_get_line_number "step-1"] +gdb_test_no_output {set $step1=$bpnum} +gdb_continue_to_breakpoint "step-1" ".* step-1 .*" +gdb_test_no_output {disable $step1} + +# 1 as we are now stopped at the `step-1' label. +set step_at 1 +for {set i 0} {$i < 100} {incr i} { + set test "step $i" + # Presume this step failed - as in the case of a timeout. + set failed 1 + gdb_test_multiple "step" $test { + -re "\r\nProgram received signal SIGUSR1, User defined signal 1.\r\n" { + exp_continue -continue_timer + } + -re "step-(\[012\]).*\r\n$gdb_prompt $" { + set now $expect_out(1,string) + if {$step_at == 2 && $now == 1} { + set failed 0 + } elseif {$step_at == 1 && $now == 2} { + set failed 0 + # Continue over the re-signalling back to the handle entry. + gdb_test_no_output {enable $step1} "" + gdb_test "continue" " step-1 .*" "" + set now 1 + gdb_test_no_output {disable $step1} "" + } else { + fail $test + } + set step_at $now + } + } + if $failed { + return + } +} +# We can never reliably say the racy problematic case has been tested. +pass "step"