gdb/testsuite/gdb.threads/detach-step-over.exp - binutils-gdb - Git at Google

 # Copyright 2021 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 <http://www.gnu.org/licenses/>.

 # Test detaching from a process that is running and has threads
 # constantly hitting a breakpoint and stepping over it, in all
 # combinations of:
 #
 #  - maint target non-stop off/on
 #  - set non-stop on/off
 #  - displaced stepping on/off
 #
 # This stresses the edge cases of detaching while a displaced step or
 # an in-line step over are in progress.
 #
 # A fail mode is that the inferior process dies after being detached.
 # This can happen because e.g.:
 #
 # - GDB leaves a breakpoint installed behind, or
 #
 # - GDB leaves a thread running in the displaced step scratch buffer.
 #   With no debugger around to run the finish step, the thread runs
 #   off of the scratch buffer, with undefined results.
 #
 # To exercise this, the testcase reattaches to the process shortly
 # after detaching, ensuring the process is still alive and well.
 #
 # In addition, since GDB may pause threads of all processes for
 # stepping over a breakpoint, it needs to re-resume all threads if it
 # detaches from the process that was just stepping over the
 # breakpoint.  To ensure that, the testcase actually runs a second
 # process at the same time as the one that is used to test detaching.
 # After the first process is detached, the testcase sends a SIGUSR1 to
 # the second process.  If threads failed to be resumed, then the
 # SIGUSR1 is never reported to the user, resulting in timeout.  The
 # threads of this second process will also be constantly stepping over
 # a breakpoint, which has helped with exposing further corner case
 # bugs.

 if {![can_spawn_for_attach]} {
     return 0
 }

 standard_testfile

 set bp_lineno [gdb_get_line_number "Set breakpoint here"]

 # The test proper.  See description above.
 proc test {condition_eval target_non_stop non_stop displaced} {
     global binfile srcfile
     global gdb_prompt
     global decimal
     global bp_lineno
     global GDBFLAGS

     # Number of threads started by the program.
     set n_threads 10

     save_vars { GDBFLAGS } {
 	append GDBFLAGS " -ex \"maint set target-non-stop $target_non_stop\""
 	append GDBFLAGS " -ex \"set non-stop $non_stop\""
 	append GDBFLAGS " -ex \"set displaced $displaced\""
 	append GDBFLAGS " -ex \"set schedule-multiple on\""
 	clean_restart $binfile
     }

     set test_spawn_id [spawn_wait_for_attach $binfile]
     set testpid [spawn_id_get_pid $test_spawn_id]

     set any "\[^\r\n\]*"

     gdb_test "add-inferior" "Added inferior 2.*"
     gdb_test "inferior 2" "Switching to .*"

     gdb_load $binfile
     if ![runto setup_done] then {
 	fail "can't run to setup_done"
 	kill_wait_spawned_process $test_spawn_id
 	return
     }

     gdb_test_no_output "set breakpoint condition-evaluation $condition_eval"

     # Get the PID of the test process.
     set pid_inf2 ""
     gdb_test_multiple "p mypid" "get pid of inferior 2" {
 	-re " = ($decimal)\r\n$gdb_prompt $" {
 	    set pid_inf2 $expect_out(1,string)
 	    pass $gdb_test_name
 	}
     }

     set attempts 3
     for {set attempt 1} { $attempt <= $attempts } { incr attempt } {
 	with_test_prefix "iter $attempt" {
 	    gdb_test "inferior 1" "Switching to .*"

 	    with_timeout_factor 2 {
 		set attached 0
 		set saw_attaching 0
 		set eperm 0
 		set test "attach"
 		gdb_test_multiple "attach $testpid" $test {
 		    -re "Attaching to program.*process $testpid\r\n" {
 			set saw_attaching 1
 			exp_continue
 		    }
 		    -re "new threads in iteration" {
 			# Seen when "set debug libthread_db" is on.
 			exp_continue
 		    }
 		    -re "Reading symbols from|Expanding full symbols from" {
 			# Prevent -readnow timeout.
 			exp_continue
 		    }
 		    -re "is a zombie - the process has already terminated.*$gdb_prompt " {
 			fail $gdb_test_name
 		    }
 		    -re "Unable to attach: .*$gdb_prompt " {
 			fail $gdb_test_name
 		    }
 		    -re "\r\n$gdb_prompt " {
 			if { $saw_attaching } {
 			    set attached 1
 			    pass $test
 			} else {
 			    fail $test
 			}
 		    }
 		}
 	    }

 	    if {!$attached} {
 		kill_wait_spawned_process $test_spawn_id
 		return
 	    }

 	    if {$non_stop} {
 		# In non-stop, we will see one stop per thread after
 		# the prompt.
 		set stops 0
 		set tid_re "$::decimal\.$::decimal"
 		set test "seen all stops"
 		for {set thread 1} { $thread <= $n_threads } { incr thread } {
 		    if {[gdb_test_multiple "" $test {
 			-re "Thread ${tid_re} ${any} stopped" {
 			    incr stops
 			}
 		    }] != 0} {
 			break
 		    }
 		}

 		# If we haven't seen all stops, then the
 		# gdb_test_multiple in the loop above will have
 		# already issued a FAIL.
 		if {$stops != $n_threads} {
 		    kill_wait_spawned_process $test_spawn_id
 		    return
 		}
 		pass $test
 	    }

 	    # Set threads stepping over a breakpoint continuously.
 	    gdb_test "break $srcfile:$bp_lineno if 0" "Breakpoint.*" \
 		"break LOC if 0"

 	    if {$attempt < $attempts} {
 		# Kick the time out timer for another round.
 		gdb_test "print again = 1" " = 1" "reset timer in the inferior"
 		# Show the time we had left in the logs, in case
 		# something goes wrong.
 		gdb_test "print seconds_left" " = .*"
 	    }

 	    if {$non_stop} {
 		set cont_cmd "continue -a &"
 	    } else {
 		set cont_cmd "continue &"
 	    }

 	    set cont_cmd_re [string_to_regexp $cont_cmd]
 	    gdb_test_multiple $cont_cmd "" {
 		-re "^$cont_cmd_re\r\nContinuing\.\r\n$gdb_prompt " {
 		    pass $gdb_test_name
 		}
 	    }

 	    # Wait a bit, to give time for the threads to hit the
 	    # breakpoint.
 	    sleep 1

 	    set running_count 0
 	    set interrupted 0
 	    gdb_test_multiple "info threads" "all threads running" {
 		-re "\\(running\\)" {
 		    incr running_count
 		    exp_continue
 		}
 		-re "Cannot execute this command while the target is running.*$gdb_prompt $" {
 		    # Testing against a remote server that doesn't do
 		    # non-stop mode.  Explicitly interrupt.  This
 		    # doesn't test the same code paths in GDB, but
 		    # it's still something.
 		    set interrupted 1
 		    gdb_test_multiple "interrupt" "" {
 			-re "$gdb_prompt " {
 			    gdb_test_multiple "" $gdb_test_name {
 				-re "received signal SIGINT, Interrupt" {
 				    pass $gdb_test_name
 				}
 			    }
 			}
 		    }
 		}
 		-re "$gdb_prompt $" {
 		    gdb_assert {$running_count == ($n_threads + 1) * 2} $gdb_test_name
 		}
 	    }

 	    gdb_test "detach" "Detaching from.*"

 	    if {!$interrupted} {
 		# Now test whether inferior 2's thread were really left
 		# running.  Currently an inline step-over stops all
 		# threads of all processes.  If detach aborts such a step
 		# over, then threads of other inferiors should be
 		# re-resumed.  Test for that by sending a signal to
 		# inferior 2.
 		remote_exec target "kill -SIGUSR1 ${pid_inf2}"

 		gdb_test_multiple "" "stop with SIGUSR1" {
 		    -re "received signal SIGUSR1" {
 			pass $gdb_test_name
 		    }
 		}
 	    }

 	    delete_breakpoints
 	}
     }
     kill_wait_spawned_process $test_spawn_id
 }

 # The test program exits after a while, in case GDB crashes.  Make it
 # wait at least as long as we may wait before declaring a time out
 # failure.
 set options { "additional_flags=-DTIMEOUT=$timeout" debug pthreads }

 if {[prepare_for_testing "failed to prepare" $testfile $srcfile $options] == -1} {
     return -1
 }

 if ![runto_main] {
     return -1
 }

 # Probe support for "set breakpoint condition-evaluation target".
 # This setting influences who steps over the breakpoint, the (remote)
 # target (e.g. gdbserver) or gdb, thus exposing issues on either the
 # target or gdb.
 set supports_condition_eval_target 1
 set cmd "set breakpoint condition-evaluation target"
 gdb_test_multiple $cmd "probe condition-evaluation target support" {
     -re "warning: Target does not support breakpoint condition evaluation.\r\nUsing host evaluation mode instead.\r\n$gdb_prompt $" {
 	# Target doesn't support breakpoint condition evaluation on
 	# its side.
 	set supports_condition_eval_target 0
 	pass $gdb_test_name
     }
     -re "^$cmd\r\n$gdb_prompt $" {
 	pass $gdb_test_name
     }
 }

 foreach_with_prefix breakpoint-condition-evaluation {"host" "target"} {
     if {!$supports_condition_eval_target && ${breakpoint-condition-evaluation} == "target"} {
 	continue
     }

     foreach_with_prefix target-non-stop {"off" "on"} {
 	foreach_with_prefix non-stop {"off" "on"} {
 	    if {${non-stop} && !${target-non-stop}} {
 		# "set non-stop" overrides "maint set
 		# target-non-stop", no use testing this combination.
 		continue
 	    }

 	    foreach_with_prefix displaced {"off" "auto"} {
 		test ${breakpoint-condition-evaluation} ${target-non-stop} ${non-stop} ${displaced}
 	    }
 	}
     }
 }
	# Copyright 2021 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 <http://www.gnu.org/licenses/>.

	# Test detaching from a process that is running and has threads
	# constantly hitting a breakpoint and stepping over it, in all
	# combinations of:
	#
	# - maint target non-stop off/on
	# - set non-stop on/off
	# - displaced stepping on/off
	#
	# This stresses the edge cases of detaching while a displaced step or
	# an in-line step over are in progress.
	#
	# A fail mode is that the inferior process dies after being detached.
	# This can happen because e.g.:
	#
	# - GDB leaves a breakpoint installed behind, or
	#
	# - GDB leaves a thread running in the displaced step scratch buffer.
	# With no debugger around to run the finish step, the thread runs
	# off of the scratch buffer, with undefined results.
	#
	# To exercise this, the testcase reattaches to the process shortly
	# after detaching, ensuring the process is still alive and well.
	#
	# In addition, since GDB may pause threads of all processes for
	# stepping over a breakpoint, it needs to re-resume all threads if it
	# detaches from the process that was just stepping over the
	# breakpoint. To ensure that, the testcase actually runs a second
	# process at the same time as the one that is used to test detaching.
	# After the first process is detached, the testcase sends a SIGUSR1 to
	# the second process. If threads failed to be resumed, then the
	# SIGUSR1 is never reported to the user, resulting in timeout. The
	# threads of this second process will also be constantly stepping over
	# a breakpoint, which has helped with exposing further corner case
	# bugs.

	if {![can_spawn_for_attach]} {
	return 0
	}

	standard_testfile

	set bp_lineno [gdb_get_line_number "Set breakpoint here"]

	# The test proper. See description above.
	proc test {condition_eval target_non_stop non_stop displaced} {
	global binfile srcfile
	global gdb_prompt
	global decimal
	global bp_lineno
	global GDBFLAGS

	# Number of threads started by the program.
	set n_threads 10

	save_vars { GDBFLAGS } {
	append GDBFLAGS " -ex \"maint set target-non-stop $target_non_stop\""
	append GDBFLAGS " -ex \"set non-stop $non_stop\""
	append GDBFLAGS " -ex \"set displaced $displaced\""
	append GDBFLAGS " -ex \"set schedule-multiple on\""
	clean_restart $binfile
	}

	set test_spawn_id [spawn_wait_for_attach $binfile]
	set testpid [spawn_id_get_pid $test_spawn_id]

	set any "\[^\r\n\]*"

	gdb_test "add-inferior" "Added inferior 2.*"
	gdb_test "inferior 2" "Switching to .*"

	gdb_load $binfile
	if ![runto setup_done] then {
	fail "can't run to setup_done"
	kill_wait_spawned_process $test_spawn_id
	return
	}

	gdb_test_no_output "set breakpoint condition-evaluation $condition_eval"

	# Get the PID of the test process.
	set pid_inf2 ""
	gdb_test_multiple "p mypid" "get pid of inferior 2" {
	-re " = ($decimal)\r\n$gdb_prompt $" {
	set pid_inf2 $expect_out(1,string)
	pass $gdb_test_name
	}
	}

	set attempts 3
	for {set attempt 1} { $attempt <= $attempts } { incr attempt } {
	with_test_prefix "iter $attempt" {
	gdb_test "inferior 1" "Switching to .*"

	with_timeout_factor 2 {
	set attached 0
	set saw_attaching 0
	set eperm 0
	set test "attach"
	gdb_test_multiple "attach $testpid" $test {
	-re "Attaching to program.*process $testpid\r\n" {
	set saw_attaching 1
	exp_continue
	}
	-re "new threads in iteration" {
	# Seen when "set debug libthread_db" is on.
	exp_continue
	}
	-re "Reading symbols from\|Expanding full symbols from" {
	# Prevent -readnow timeout.
	exp_continue
	}
	-re "is a zombie - the process has already terminated.*$gdb_prompt " {
	fail $gdb_test_name
	}
	-re "Unable to attach: .*$gdb_prompt " {
	fail $gdb_test_name
	}
	-re "\r\n$gdb_prompt " {
	if { $saw_attaching } {
	set attached 1
	pass $test
	} else {
	fail $test
	}
	}
	}
	}

	if {!$attached} {
	kill_wait_spawned_process $test_spawn_id
	return
	}

	if {$non_stop} {
	# In non-stop, we will see one stop per thread after
	# the prompt.
	set stops 0
	set tid_re "$::decimal\.$::decimal"
	set test "seen all stops"
	for {set thread 1} { $thread <= $n_threads } { incr thread } {
	if {[gdb_test_multiple "" $test {
	-re "Thread ${tid_re} ${any} stopped" {
	incr stops
	}
	}] != 0} {
	break
	}
	}

	# If we haven't seen all stops, then the
	# gdb_test_multiple in the loop above will have
	# already issued a FAIL.
	if {$stops != $n_threads} {
	kill_wait_spawned_process $test_spawn_id
	return
	}
	pass $test
	}

	# Set threads stepping over a breakpoint continuously.
	gdb_test "break $srcfile:$bp_lineno if 0" "Breakpoint.*" \
	"break LOC if 0"

	if {$attempt < $attempts} {
	# Kick the time out timer for another round.
	gdb_test "print again = 1" " = 1" "reset timer in the inferior"
	# Show the time we had left in the logs, in case
	# something goes wrong.
	gdb_test "print seconds_left" " = .*"
	}

	if {$non_stop} {
	set cont_cmd "continue -a &"
	} else {
	set cont_cmd "continue &"
	}

	set cont_cmd_re [string_to_regexp $cont_cmd]
	gdb_test_multiple $cont_cmd "" {
	-re "^$cont_cmd_re\r\nContinuing\.\r\n$gdb_prompt " {
	pass $gdb_test_name
	}
	}

	# Wait a bit, to give time for the threads to hit the
	# breakpoint.
	sleep 1

	set running_count 0
	set interrupted 0
	gdb_test_multiple "info threads" "all threads running" {
	-re "\\(running\\)" {
	incr running_count
	exp_continue
	}
	-re "Cannot execute this command while the target is running.*$gdb_prompt $" {
	# Testing against a remote server that doesn't do
	# non-stop mode. Explicitly interrupt. This
	# doesn't test the same code paths in GDB, but
	# it's still something.
	set interrupted 1
	gdb_test_multiple "interrupt" "" {
	-re "$gdb_prompt " {
	gdb_test_multiple "" $gdb_test_name {
	-re "received signal SIGINT, Interrupt" {
	pass $gdb_test_name
	}
	}
	}
	}
	}
	-re "$gdb_prompt $" {
	gdb_assert {$running_count == ($n_threads + 1) * 2} $gdb_test_name
	}
	}

	gdb_test "detach" "Detaching from.*"

	if {!$interrupted} {
	# Now test whether inferior 2's thread were really left
	# running. Currently an inline step-over stops all
	# threads of all processes. If detach aborts such a step
	# over, then threads of other inferiors should be
	# re-resumed. Test for that by sending a signal to
	# inferior 2.
	remote_exec target "kill -SIGUSR1 ${pid_inf2}"

	gdb_test_multiple "" "stop with SIGUSR1" {
	-re "received signal SIGUSR1" {
	pass $gdb_test_name
	}
	}
	}

	delete_breakpoints
	}
	}
	kill_wait_spawned_process $test_spawn_id
	}

	# The test program exits after a while, in case GDB crashes. Make it
	# wait at least as long as we may wait before declaring a time out
	# failure.
	set options { "additional_flags=-DTIMEOUT=$timeout" debug pthreads }

	if {[prepare_for_testing "failed to prepare" $testfile $srcfile $options] == -1} {
	return -1
	}

	if ![runto_main] {
	return -1
	}

	# Probe support for "set breakpoint condition-evaluation target".
	# This setting influences who steps over the breakpoint, the (remote)
	# target (e.g. gdbserver) or gdb, thus exposing issues on either the
	# target or gdb.
	set supports_condition_eval_target 1
	set cmd "set breakpoint condition-evaluation target"
	gdb_test_multiple $cmd "probe condition-evaluation target support" {
	-re "warning: Target does not support breakpoint condition evaluation.\r\nUsing host evaluation mode instead.\r\n$gdb_prompt $" {
	# Target doesn't support breakpoint condition evaluation on
	# its side.
	set supports_condition_eval_target 0
	pass $gdb_test_name
	}
	-re "^$cmd\r\n$gdb_prompt $" {
	pass $gdb_test_name
	}
	}

	foreach_with_prefix breakpoint-condition-evaluation {"host" "target"} {
	if {!$supports_condition_eval_target && ${breakpoint-condition-evaluation} == "target"} {
	continue
	}

	foreach_with_prefix target-non-stop {"off" "on"} {
	foreach_with_prefix non-stop {"off" "on"} {
	if {${non-stop} && !${target-non-stop}} {
	# "set non-stop" overrides "maint set
	# target-non-stop", no use testing this combination.
	continue
	}

	foreach_with_prefix displaced {"off" "auto"} {
	test ${breakpoint-condition-evaluation} ${target-non-stop} ${non-stop} ${displaced}
	}
	}
	}
	}