binutils-gdb/gdb/testsuite/gdb.base/sigstep.exp

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# Copyright 2004-2015 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/>.
# The program sigstep.c creates a very simple backtrace containing one
# signal handler and signal trampoline. A flag is set and then the
# handler returns. This is repeated at infinitum.
# This test runs the program up to the signal handler, and then
# attempts to step/next out of the handler and back into main.
if [target_info exists gdb,nosignals] {
verbose "Skipping sigstep.exp because of nosignals."
continue
}
standard_testfile
if {[build_executable $testfile.exp $testfile $srcfile debug]} {
untested $testfile.exp
return -1
}
set clear_done [gdb_get_line_number {done = 0}]
set infinite_loop [gdb_get_line_number {while (!done)}]
set other_handler_location [gdb_get_line_number "other handler location"]
# Restart GDB, set a display showing $PC, and run to main.
proc restart {} {
global binfile
clean_restart $binfile
gdb_test "display/i \$pc"
runto_main
}
# Pass all the alarms straight through (but verbosely)
# gdb_test "handle SIGALRM print pass nostop"
# gdb_test "handle SIGVTALRM print pass nostop"
# gdb_test "handle SIGPROF print pass nostop"
# Run to the signal handler, validate the backtrace.
proc validate_backtrace {} {
with_test_prefix "validate backtrace" {
restart
gdb_test "break handler"
gdb_test "continue" ".* handler .*" "continue to stepi handler"
gdb_test_sequence "bt" "backtrace for nexti" {
"\[\r\n\]+.0 \[^\r\n\]* handler "
"\[\r\n\]+.1 .signal handler called."
"\[\r\n\]+.2 \[^\r\n\]* main "
}
}
}
validate_backtrace
# Goes to handler using ENTER_CMD, runs IN_HANDLER while in the signal
# hander, and then steps out of the signal handler using EXIT_CMD.
proc advance { enter_cmd in_handler_prefix in_handler exit_cmd } {
global gdb_prompt inferior_exited_re
global clear_done other_handler_location
set prefix "$enter_cmd to handler, $in_handler_prefix in handler, $exit_cmd from handler"
with_test_prefix $prefix {
restart
# Get us into the handler
if { $enter_cmd == "continue" } {
gdb_test "break handler"
} else {
gdb_test "handle SIGALRM print pass stop"
gdb_test "handle SIGVTALRM print pass stop"
gdb_test "continue" "Program received signal.*" "continue to signal"
}
gdb_test "$enter_cmd" ".*handler .*" "$enter_cmd to handler"
delete_breakpoints
uplevel 1 $in_handler
if { $exit_cmd == "continue" } {
gdb_test "break $clear_done" ".*" "break clear done"
}
set test "leave handler"
gdb_test_multiple "$exit_cmd" "${test}" {
-re "Could not insert single-step breakpoint.*$gdb_prompt $" {
setup_kfail gdb/8841 "sparc*-*-openbsd*"
fail "$test (could not insert single-step breakpoint)"
}
-re "Cannot insert breakpoint.*Cannot access memory.*$gdb_prompt $" {
setup_kfail gdb/8841 "nios2*-*-linux*"
fail "$test (could not insert single-step breakpoint)"
}
-re "done = 1;.*${gdb_prompt} $" {
send_gdb "$exit_cmd\n"
exp_continue -continue_timer
}
-re "\} .. handler .*${gdb_prompt} $" {
send_gdb "$exit_cmd\n"
exp_continue -continue_timer
}
-re "$inferior_exited_re normally.*${gdb_prompt} $" {
setup_kfail gdb/8744 powerpc-*-*bsd*
fail "$test (program exited)"
}
-re "(while ..done|done = 0).*${gdb_prompt} $" {
# After stepping out of a function /r signal-handler, GDB will
# advance the inferior until it is at the first instruction of
# a code-line. While typically things return to the middle of
# the "while..." (and hence GDB advances the inferior to the
# "return..." line) it is also possible for the return to land
# on the first instruction of "while...". Accept both cases.
pass "$test"
}
}
}
}
# Map of PREFIX => "things to do within the signal handler", for the
# advance tests.
set in_handler_map {
"nothing" {
}
"si+advance" {
# Advance to the second location in handler.
gdb_test "si" "handler.*" "si in handler"
set test "advance in handler"
gdb_test_multiple "advance $other_handler_location" $test {
-re "Program received signal SIGTRAP.*$gdb_prompt $" {
# On some versions of Linux (observed on
# 3.16.4-200.fc20.x86_64), using PTRACE_SINGLESTEP+sig
# to step into a signal handler, and then issuing
# another PTRACE_SINGLESTEP within the handler ends up
# with $eflags.TF mistakenly set, which results in
# subsequent PTRACE_CONTINUEs trapping after each
# insn.
if {$enter_cmd != "continue"} {
setup_xfail "i?86-*-linux*" gdb/17511
setup_xfail "x86_64-*-linux*" gdb/17511
}
fail "$test (spurious SIGTRAP)"
return
}
-re "other handler location.*$gdb_prompt $" {
pass $test
}
}
}
}
# Check that we can step/next/continue, etc. our way in and out of a
# signal handler. Also test that we can step, and run to a breakpoint
# within the handler.
foreach enter_cmd { "stepi" "nexti" "step" "next" "continue" } {
if { $enter_cmd != "continue" && ![can_single_step_to_signal_handler] } {
continue
}
foreach exit_cmd { "step" "next" "continue" } {
foreach {in_handler_prefix in_handler} $in_handler_map {
advance $enter_cmd $in_handler_prefix $in_handler $exit_cmd
}
}
}
proc advancei { cmd } {
global gdb_prompt inferior_exited_re
with_test_prefix "$cmd from handleri" {
restart
# Get us into the handler.
gdb_test "break handler"
gdb_test "continue" ".* handler .*" "continue to handler"
set program_exited 0
set test "leave handler"
gdb_test_multiple "$cmd" "${test}" {
-re "Cannot insert breakpoint 0.*${gdb_prompt} $" {
# Some platforms use a special read-only page for signal
# trampolines. We can't set a breakpoint there, and we
# don't gracefully fall back to single-stepping.
setup_kfail gdb/8841 "i?86-*-linux*"
setup_kfail gdb/8841 "*-*-openbsd*"
setup_kfail gdb/8841 "nios2-*-linux*"
fail "$test (could not set breakpoint)"
return
}
-re "Could not insert single-step breakpoint.*$gdb_prompt $" {
setup_kfail gdb/8841 "sparc*-*-openbsd*"
fail "$test (could not insert single-step breakpoint)"
}
-re "Breakpoint \[0-9\]*, handler .*${gdb_prompt} $" {
fail "$test (hit breakpoint again)"
}
-re "done = 1;.*${gdb_prompt} $" {
send_gdb "$cmd\n"
exp_continue -continue_timer
}
-re "\} .. handler .*${gdb_prompt} $" {
send_gdb "$cmd\n"
exp_continue -continue_timer
}
-re "signal handler called.*${gdb_prompt} $" {
pass "$test"
}
-re "main .*${gdb_prompt} $" {
fail "$test (in main)"
}
-re "$inferior_exited_re normally.*${gdb_prompt} $" {
fail "$test (program exited)"
set program_exited 1
}
-re "Make handler return now.*y or n. $" {
send_gdb "y\n"
exp_continue -continue_timer
}
}
set test "leave signal trampoline"
gdb_test_multiple "$cmd" "${test}" {
-re "while .*${gdb_prompt} $" {
pass "$test (in main)"
}
-re "signal handler called.*${gdb_prompt} $" {
send_gdb "$cmd\n"
exp_continue -continue_timer
}
-re "return .*${gdb_prompt} $" {
fail "$test (stepped)"
}
-re "Make .*frame return now.*y or n. $" {
send_gdb "y\n"
exp_continue -continue_timer
}
-re "$inferior_exited_re normally.*${gdb_prompt} $" {
kfail gdb/8744 "$test (program exited)"
set program_exited 1
}
-re "The program is not being run.*${gdb_prompt} $" {
if { $program_exited } {
# Previously kfailed with an exit
pass "$test (the program is not being run)"
} else {
fail "$test (the program is not being run)"
}
}
}
}
}
# Check that we can step our way out of a signal handler, using
# commands that first step out to the signal trampoline, and then out
# to the mainline code.
foreach cmd {"stepi" "nexti" "finish" "return"} {
advancei $cmd
}
# Check that we can step/next our way into / over a signal handler.
# There are at least the following cases: breakpoint @pc VS breakpoint
# in handler VS step / next / continue.
# Try stepping when there's a signal pending, and a breakpoint at the
# handler. Should step into the signal handler.
proc skip_to_handler { cmd } {
global infinite_loop
with_test_prefix "$cmd to handler" {
restart
# Use the real-time itimer, as otherwize the process never gets
# enough time to expire the timer.
gdb_test_no_output "set itimer = itimer_real"
# Advance to the infinite loop.
gdb_test "advance $infinite_loop" ".*" "advance to infinite loop"
# Make the signal pending.
sleep 1
# Insert the handler breakpoint.
gdb_test "break handler" ".*" "break handler"
# Step into the handler.
gdb_test "$cmd" " handler .*" "performing $cmd"
}
}
foreach cmd {"step" "next" "continue"} {
skip_to_handler $cmd
}
# Try stepping when there's a signal pending, and a breakpoint at the
# handler's entry-point. Should step into the signal handler stopping
# at the entry-point.
# Some systems (e.x., GNU/Linux as of 2004-08-30), when delivering a
# signal, resume the process at the first instruction of the signal
# handler and not the first instruction of the signal trampoline. The
# stack is constructed such that the signal handler still appears to
# have been called by the trampoline code. This test checks that it
# is possible to stop the inferior, even at that first instruction.
proc skip_to_handler_entry { cmd } {
global infinite_loop
with_test_prefix "$cmd to handler entry" {
restart
# Use the real-time itimer, as otherwize the process never gets
# enough time to expire the timer.
gdb_test_no_output "set itimer = itimer_real"
# Advance to the infinite loop.
gdb_test "advance $infinite_loop" ".*" "advance to infinite loop"
# Make the signal pending.
sleep 1
# Insert / remove the handler breakpoint.
gdb_test "break *handler" ".*" "break handler"
gdb_test "$cmd" " handler .*" "performing $cmd"
}
}
foreach cmd {"stepi" "nexti" "step" "next" "continue"} {
skip_to_handler_entry $cmd
}
# Get the address of where a single-step should land.
proc get_next_pc {test} {
global gdb_prompt
global hex
set next ""
gdb_test_multiple "x/2i \$pc" $test {
-re "$hex .*:\[^\r\n\]+\r\n\[ \]+($hex).*\.\r\n$gdb_prompt $" {
set next $expect_out(1,string)
pass $test
}
}
return $next
}
# Test that the command skipped over the handler.
proc test_skip_handler {cmd} {
if {$cmd == "stepi" || $cmd == "nexti"} {
set next_pc [get_next_pc "get next PC"]
gdb_test "$cmd" "dummy = 0.*" "performing $cmd"
gdb_test "p /x \$pc" " = $next_pc" "advanced"
} else {
gdb_test "$cmd" "done = 0.*" "performing $cmd"
}
}
# Try stepping when there's a signal pending but no breakpoints.
# Should skip the handler advancing to the next line.
proc skip_over_handler { cmd } {
global infinite_loop
global clear_done
with_test_prefix "$cmd over handler" {
restart
# Use the real-time itimer, as otherwize the process never gets
# enough time to expire the timer.
gdb_test_no_output "set itimer = itimer_real"
gdb_test "break $clear_done" ".*" "break clear done"
# Advance to the infinite loop.
gdb_test "advance $infinite_loop" ".*" "advance to infinite loop"
# Make the signal pending.
sleep 1
test_skip_handler $cmd
}
}
foreach cmd {"stepi" "nexti" "step" "next" "continue"} {
skip_over_handler $cmd
}
# Try stepping when there's a signal pending, a pre-existing
# breakpoint at the current instruction, and a breakpoint in the
# handler. Should advance to the signal handler. DISPLACED indicates
# whether to try with or without displaced stepping (to exercise the
# different techniques of stepping over the breakpoint at the current
# instruction).
proc breakpoint_to_handler { displaced cmd } {
global infinite_loop
with_test_prefix "displaced=$displaced: $cmd on breakpoint, to handler" {
restart
gdb_test_no_output "set displaced-stepping $displaced"
# Use the real-time itimer, as otherwize the process never gets
# enough time to expire the timer.
gdb_test_no_output "set itimer = itimer_real"
gdb_test "break $infinite_loop" ".*" "break infinite loop"
gdb_test "break handler" ".*" "break handler"
# Continue to the infinite loop.
gdb_test "continue" "while ..done.*" "continue to infinite loop"
# Make the signal pending.
sleep 1
gdb_test "$cmd" " handler .*" "performing $cmd"
# Make sure we the displaced stepping scratch pad isn't in the
# backtrace.
gdb_test_sequence "bt" "backtrace" {
"\[\r\n\]+.0 \[^\r\n\]* handler "
"\[\r\n\]+.1 .signal handler called."
"\[\r\n\]+.2 \[^\r\n\]* main "
}
}
}
foreach displaced {"off" "on"} {
foreach cmd {"step" "next" "continue"} {
breakpoint_to_handler $displaced $cmd
}
}
# Try stepping when there's a signal pending, and a breakpoint at the
# handler's entry instruction and a breakpoint at the current
# instruction. Should step into the signal handler and breakpoint at
# that entry instruction.
# Some systems (e.x., GNU/Linux as of 2004-08-30), when delivering a
# signal, resume the process at the first instruction of the signal
# handler and not the first instruction of the signal trampoline. The
# stack is constructed such that the signal handler still appears to
# have been called by the trampoline code. This test checks that it
# is possible to stop the inferior, even at that first instruction.
# DISPLACED indicates whether to try with or without displaced
# stepping (to exercise the different techniques of stepping over the
# breakpoint at the current instruction).
proc breakpoint_to_handler_entry { displaced cmd } {
global infinite_loop
with_test_prefix "displaced=$displaced: $cmd on breakpoint, to handler entry" {
restart
gdb_test_no_output "set displaced-stepping $displaced"
# Use the real-time itimer, as otherwize the process never gets
# enough time to expire the timer.
gdb_test_no_output "set itimer = itimer_real"
gdb_test "break $infinite_loop" ".*" "break infinite loop"
gdb_test "break *handler" ".*" "break handler"
# Continue to the infinite loop.
gdb_test "continue" "while ..done.*" "continue to infinite loop"
# Make the signal pending.
sleep 1
gdb_test "$cmd" " handler .*" "performing $cmd"
# Make sure we the displaced stepping scratch pad isn't in the
# backtrace.
gdb_test_sequence "bt" "backtrace" {
"\[\r\n\]+.0 \[^\r\n\]* handler "
"\[\r\n\]+.1 .signal handler called."
"\[\r\n\]+.2 \[^\r\n\]* main "
}
}
}
foreach displaced {"off" "on"} {
foreach cmd {"step" "next" "continue"} {
breakpoint_to_handler_entry $displaced $cmd
}
}
# Try stepping when there's a signal pending, and a pre-existing
# breakpoint at the current instruction, and no breakpoint in the
# handler. Should advance to the next line/instruction. DISPLACED
# indicates whether to try with or without displaced stepping (to
# exercise the different techniques of stepping over the breakpoint at
# the current instruction). If SW_WATCH is true, set a software
# watchpoint, which exercises stepping the breakpoint instruction
# while delivering a signal at the same time. If NO_HANDLER, arrange
# for the signal's handler be SIG_IGN, thus when the software
# watchpoint is also set, testing stepping a breakpoint instruction
# and immediately triggering the breakpoint (exercises
# adjust_pc_after_break logic).
proc breakpoint_over_handler { displaced cmd with_sw_watch no_handler } {
global infinite_loop
global clear_done
set prefix "$cmd on breakpoint, skip handler"
if { $with_sw_watch } {
append prefix ", with sw-watchpoint"
}
if { $no_handler } {
append prefix ", no handler"
}
with_test_prefix "displaced=$displaced: $prefix" {
restart
gdb_test_no_output "set displaced-stepping $displaced"
# Use the real-time itimer, as otherwize the process never gets
# enough time to expire the timer.
gdb_test_no_output "set itimer = itimer_real"
if {$no_handler} {
gdb_test "print no_handler = 1" " = 1" \
"set no_handler"
}
gdb_test "break $infinite_loop" ".*" "break infinite loop"
gdb_test "break $clear_done" ".*" "break clear done"
# Continue to the infinite loop
gdb_test "continue" "while ..done.*" "continue to infinite loop"
# Make the signal pending
sleep 1
if { $with_sw_watch } {
# A watchpoint on a convenience variable is always a
# software watchpoint.
gdb_test "watch \$convenience" "Watchpoint .*: \\\$convenience"
}
if {$no_handler} {
# With no handler, we need to set the global ourselves
# manually.
gdb_test "print done = 1" " = 1" "set done"
}
test_skip_handler $cmd
}
}
foreach displaced {"off" "on"} {
foreach cmd {"stepi" "nexti" "step" "next" "continue"} {
foreach with_sw_watch {0 1} {
foreach no_handler {0 1} {
breakpoint_over_handler $displaced $cmd $with_sw_watch $no_handler
}
}
}
}