# This testcase is part of GDB, the GNU debugger.
# Copyright 2004, 2005 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 2 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, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
# Check that GDB can and only executes single instructions when
# stepping through a sequence of breakpoints interleaved by a signal
# handler.
# This test is known to tickle the following problems: kernel letting
# the inferior execute both the system call, and the instruction
# following, when single-stepping a system call; kernel failing to
# propogate the single-step state when single-stepping the sigreturn
# system call, instead resuming the inferior at full speed; GDB
# doesn't know how to software single-step across a sigreturn
# instruction. Since the kernel problems can be "fixed" using
# software single-step this is KFAILed rather than XFAILed.
if [target_info exists gdb,nosignals] {
verbose "Skipping signals.exp because of nosignals."
continue
}
if $tracelevel {
strace $tracelevel
}
set prms_id 0
set bug_id 0
set testfile "sigbpt"
set srcfile ${testfile}.c
set binfile ${objdir}/${subdir}/${testfile}
if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug}] != "" } {
gdb_suppress_entire_file "Testcase compile failed, so all tests in this file will automatically fail."
}
# APPLE LOCAL begin signal name
if [istarget "*-apple-darwin*"] {
set signame "EXC_BAD_ACCESS"
} else {
set signame "SIGSEGV"
}
# APPLE LOCAL begin signal name
gdb_exit
gdb_start
gdb_reinitialize_dir $srcdir/$subdir
gdb_load ${binfile}
#
# Run to `main' where we begin our tests.
#
if ![runto_main] then {
gdb_suppress_tests
}
# If we can examine what's at memory address 0, it is possible that we
# could also execute it. This could probably make us run away,
# executing random code, which could have all sorts of ill effects,
# especially on targets without an MMU. Don't run the tests in that
# case.
send_gdb "x 0\n"
gdb_expect {
-re "0x0:.*Cannot access memory at address 0x0.*$gdb_prompt $" { }
-re "0x0:.*Error accessing memory address 0x0.*$gdb_prompt $" { }
-re ".*$gdb_prompt $" {
untested "Memory at address 0 is possibly executable"
return
}
}
gdb_test "break keeper"
# Run to bowler, and then single step until there's a SIGSEGV. Record
# the address of each single-step instruction (up to and including the
# instruction that causes the SIGSEGV) in bowler_addrs, and the address
# of the actual SIGSEGV in segv_addr.
set bowler_addrs bowler
gdb_test {display/i $pc}
gdb_test "advance *bowler" "bowler.*" "advance to the bowler"
set test "stepping to SIGSEGV"
# APPLE LOCAL signal name
gdb_test_multiple "stepi" "$test" {
-re "Program received signal ${signame}.*pc *(0x\[0-9a-f\]*).*$gdb_prompt $" {
set segv_addr $expect_out(1,string)
pass "$test"
}
-re " .*pc *(0x\[0-9a-f\]*).*bowler.*$gdb_prompt $" {
set bowler_addrs [concat $expect_out(1,string) $bowler_addrs]
send_gdb "stepi\n"
exp_continue
}
}
# Now record the address of the instruction following the faulting
# instruction in bowler_addrs.
set test "get insn after fault"
gdb_test_multiple {x/2i $pc} "$test" {
-re "(0x\[0-9a-f\]*).*bowler.*(0x\[0-9a-f\]*).*bowler.*$gdb_prompt $" {
set bowler_addrs [concat $expect_out(2,string) $bowler_addrs]
pass "$test"
}
}
# Procedures for returning the address of the instruction before, at
# and after, the faulting instruction.
proc before_segv { } {
global bowler_addrs
return [lindex $bowler_addrs 2]
}
proc at_segv { } {
global bowler_addrs
return [lindex $bowler_addrs 1]
}
proc after_segv { } {
global bowler_addrs
return [lindex $bowler_addrs 0]
}
# Check that the address table and SIGSEGV correspond.
set test "Verify that SIGSEGV occurs at the last STEPI insn"
if {[string compare $segv_addr [at_segv]] == 0} {
pass "$test"
} else {
fail "$test ($segv_addr [at_segv])"
}
# Check that the inferior is correctly single stepped all the way back
# to a faulting instruction.
# APPLE LOCAL signal name
proc stepi_out { name signame args } {
global gdb_prompt
# Set SIGSEGV to pass+nostop and then run the inferior all the way
# through to the signal handler. With the handler is reached,
# disable SIGSEGV, ensuring that further signals stop the
# inferior. Stops a SIGSEGV infinite loop when a broke system
# keeps re-executing the faulting instruction.
rerun_to_main
# APPLE LOCAL signal name
gdb_test "handle ${signame} nostop print pass" "" "${name}; pass SIGSEGV"
gdb_test "continue" "keeper.*" "${name}; continue to keeper"
# APPLE LOCAL signal name
gdb_test "handle ${signame} stop print nopass" "" "${name}; nopass SIGSEGV"
# Insert all the breakpoints. To avoid the need to step over
# these instructions, this is delayed until after the keeper has
# been reached.
for {set i 0} {$i < [llength $args]} {incr i} {
gdb_test "break [lindex $args $i]" "Breakpoint.*" \
"${name}; set breakpoint $i of [llength $args]"
}
# Single step our way out of the keeper, through the signal
# trampoline, and back to the instruction that faulted.
set test "${name}; stepi out of handler"
# APPLE LOCAL signal name
gdb_test_multiple "stepi" "$test" {
-re "keeper.*$gdb_prompt $" {
send_gdb "stepi\n"
exp_continue
}
-re "signal handler.*$gdb_prompt $" {
send_gdb "stepi\n"
exp_continue
}
-re "Program received signal ${signame}.*$gdb_prompt $" {
kfail gdb/1702 "$test (executed fault insn)"
}
-re "Breakpoint.*pc *[at_segv] .*bowler.*$gdb_prompt $" {
pass "$test (at breakpoint)"
}
-re "Breakpoint.*pc *[after_segv] .*bowler.*$gdb_prompt $" {
kfail gdb/1702 "$test (executed breakpoint)"
}
-re "pc *[at_segv] .*bowler.*$gdb_prompt $" {
pass "$test"
}
-re "pc *[after_segv] .*bowler.*$gdb_prompt $" {
kfail gdb/1702 "$test (skipped fault insn)"
}
-re "pc *0x\[a-z0-9\]* .*bowler.*$gdb_prompt $" {
kfail gdb/1702 "$test (corrupt pc)"
}
}
# Clear any breakpoints
for {set i 0} {$i < [llength $args]} {incr i} {
gdb_test "clear [lindex $args $i]" "Deleted .*" \
"${name}; clear breakpoint $i of [llength $args]"
}
}
# Let a signal handler exit, returning to a breakpoint instruction
# inserted at the original fault instruction. Check that the
# breakpoint is hit, and that single stepping off that breakpoint
# executes the underlying fault instruction causing a SIGSEGV.
# APPLE LOCAL signal name
proc cont_out { name signame args } {
global gdb_prompt
# Set SIGSEGV to pass+nostop and then run the inferior all the way
# through to the signal handler. With the handler is reached,
# disable SIGSEGV, ensuring that further signals stop the
# inferior. Stops a SIGSEGV infinite loop when a broke system
# keeps re-executing the faulting instruction.
rerun_to_main
# APPLE LOCAL signal name
gdb_test "handle ${signame} nostop print pass" "" "${name}; pass SIGSEGV"
gdb_test "continue" "keeper.*" "${name}; continue to keeper"
# APPLE LOCAL signal name
gdb_test "handle ${signame} stop print nopass" "" "${name}; nopass SIGSEGV"
# Insert all the breakpoints. To avoid the need to step over
# these instructions, this is delayed until after the keeper has
# been reached. Always set a breakpoint at the signal trampoline
# instruction.
set args [concat $args "*[at_segv]"]
for {set i 0} {$i < [llength $args]} {incr i} {
gdb_test "break [lindex $args $i]" "Breakpoint.*" \
"${name}; set breakpoint $i of [llength $args]"
}
# Let the handler return, it should "appear to hit" the breakpoint
# inserted at the faulting instruction. Note that the breakpoint
# instruction wasn't executed, rather the inferior was SIGTRAPed
# with the PC at the breakpoint.
gdb_test "continue" "Breakpoint.*pc *[at_segv] .*" \
"${name}; continue to breakpoint at fault"
# Now single step the faulted instrction at that breakpoint.
# APPLE LOCAL signal name
gdb_test "stepi" \
"Program received signal ${signame}.*pc *[at_segv] .*" \
"${name}; stepi fault"
# Clear any breakpoints
for {set i 0} {$i < [llength $args]} {incr i} {
gdb_test "clear [lindex $args $i]" "Deleted .*" \
"${name}; clear breakpoint $i of [llength $args]"
}
}
# APPLE LOCAL begin signal name
if [istarget "*-apple-darwin*"] {
warning "Darwin unable to single-step through exceptions, skipping rest of tests"
continue
}
# APPLE LOCAL end signal name
# Try to confuse DECR_PC_AFTER_BREAK architectures by scattering
# breakpoints around the faulting address. In all cases the inferior
# should single-step out of the signal trampoline halting (but not
# executing) the fault instruction.
# APPLE LOCAL begin signal name
stepi_out "stepi" ${signame}
stepi_out "stepi bp before segv" ${signame} "*[before_segv]"
stepi_out "stepi bp at segv" ${signame} "*[at_segv]"
stepi_out "stepi bp before and at segv" ${signame} "*[at_segv]" "*[before_segv]"
# APPLE LOCAL end signal name
# Try to confuse DECR_PC_AFTER_BREAK architectures by scattering
# breakpoints around the faulting address. In all cases the inferior
# should exit the signal trampoline halting at the breakpoint that
# replaced the fault instruction.
# APPLE LOCAL begin signal name
cont_out "cont" ${signame}
cont_out "cont bp after segv" ${signame} "*[before_segv]"
cont_out "cont bp before and after segv" ${signame} "*[before_segv]" "*[after_segv]"
# APPLE LOCAL end signal name