gdb/testsuite/gdb.base/sigbpt.exp

   1 # This testcase is part of GDB, the GNU debugger.
   2
   3 # Copyright 2004, 2005 Free Software Foundation, Inc.
   4
   5 # This program is free software; you can redistribute it and/or modify
   6 # it under the terms of the GNU General Public License as published by
   7 # the Free Software Foundation; either version 2 of the License, or
   8 # (at your option) any later version.
   9 #
  10 # This program is distributed in the hope that it will be useful,
  11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 # GNU General Public License for more details.
  14 #
  15 # You should have received a copy of the GNU General Public License
  16 # along with this program; if not, write to the Free Software
  17 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  18
  19 # Check that GDB can and only executes single instructions when
  20 # stepping through a sequence of breakpoints interleaved by a signal
  21 # handler.
  22
  23 # This test is known to tickle the following problems: kernel letting
  24 # the inferior execute both the system call, and the instruction
  25 # following, when single-stepping a system call; kernel failing to
  26 # propogate the single-step state when single-stepping the sigreturn
  27 # system call, instead resuming the inferior at full speed; GDB
  28 # doesn't know how to software single-step across a sigreturn
  29 # instruction.  Since the kernel problems can be "fixed" using
  30 # software single-step this is KFAILed rather than XFAILed.
  31
  32 if [target_info exists gdb,nosignals] {
  33     verbose "Skipping signals.exp because of nosignals."
  34     continue
  35 }
  36
  37 if $tracelevel {
  38     strace $tracelevel
  39 }
  40
  41 set prms_id 0
  42 set bug_id 0
  43
  44 set testfile "sigbpt"
  45 set srcfile ${testfile}.c
  46 set binfile ${objdir}/${subdir}/${testfile}
  47 if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug}] != "" } {
  48     gdb_suppress_entire_file "Testcase compile failed, so all tests in this file will automatically fail."
  49 }
  50
  51 gdb_exit
  52 gdb_start
  53 gdb_reinitialize_dir $srcdir/$subdir
  54 gdb_load ${binfile}
  55
  56 #
  57 # Run to `main' where we begin our tests.
  58 #
  59
  60 if ![runto_main] then {
  61     gdb_suppress_tests
  62 }
  63
  64 # If we can examine what's at memory address 0, it is possible that we
  65 # could also execute it.  This could probably make us run away,
  66 # executing random code, which could have all sorts of ill effects,
  67 # especially on targets without an MMU.  Don't run the tests in that
  68 # case.
  69
  70 send_gdb "x 0\n"
  71 gdb_expect {
  72     -re "0x0:.*Cannot access memory at address 0x0.*$gdb_prompt $" { }
  73     -re "0x0:.*Error accessing memory address 0x0.*$gdb_prompt $" { }
  74     -re ".*$gdb_prompt $" {
  75         untested "Memory at address 0 is possibly executable"
  76         return
  77     }
  78 }
  79
  80 gdb_test "break keeper"
  81
  82 # Run to bowler, and then single step until there's a SIGSEGV.  Record
  83 # the address of each single-step instruction (up to and including the
  84 # instruction that causes the SIGSEGV) in bowler_addrs, and the address
  85 # of the actual SIGSEGV in segv_addr.
  86
  87 set bowler_addrs bowler
  88 gdb_test {display/i $pc}
  89 gdb_test "advance *bowler" "bowler.*" "advance to the bowler"
  90 set test "stepping to SIGSEGV"
  91 gdb_test_multiple "stepi" "$test" {
  92     -re "Program received signal SIGSEGV.*pc *(0x\[0-9a-f\]*).*$gdb_prompt $" {
  93         set segv_addr $expect_out(1,string)
  94         pass "$test"
  95     }
  96     -re " .*pc *(0x\[0-9a-f\]*).*bowler.*$gdb_prompt $" {
  97         set bowler_addrs [concat $expect_out(1,string) $bowler_addrs]
  98         send_gdb "stepi\n"
  99         exp_continue
 100     }
 101 }
 102
 103 # Now record the address of the instruction following the faulting
 104 # instruction in bowler_addrs.
 105
 106 set test "get insn after fault"
 107 gdb_test_multiple {x/2i $pc} "$test" {
 108     -re "(0x\[0-9a-f\]*).*bowler.*(0x\[0-9a-f\]*).*bowler.*$gdb_prompt $" {
 109         set bowler_addrs [concat $expect_out(2,string) $bowler_addrs]
 110         pass "$test"
 111     }
 112 }
 113
 114 # Procedures for returning the address of the instruction before, at
 115 # and after, the faulting instruction.
 116
 117 proc before_segv { } {
 118     global bowler_addrs
 119     return [lindex $bowler_addrs 2]
 120 }
 121
 122 proc at_segv { } {
 123     global bowler_addrs
 124     return [lindex $bowler_addrs 1]
 125 }
 126
 127 proc after_segv { } {
 128     global bowler_addrs
 129     return [lindex $bowler_addrs 0]
 130 }
 131
 132 # Check that the address table and SIGSEGV correspond.
 133
 134 set test "Verify that SIGSEGV occurs at the last STEPI insn"
 135 if {[string compare $segv_addr [at_segv]] == 0} {
 136     pass "$test"
 137 } else {
 138     fail "$test ($segv_addr [at_segv])"
 139 }
 140
 141 # Check that the inferior is correctly single stepped all the way back
 142 # to a faulting instruction.
 143
 144 proc stepi_out { name args } {
 145     global gdb_prompt
 146
 147     # Set SIGSEGV to pass+nostop and then run the inferior all the way
 148     # through to the signal handler.  With the handler is reached,
 149     # disable SIGSEGV, ensuring that further signals stop the
 150     # inferior.  Stops a SIGSEGV infinite loop when a broke system
 151     # keeps re-executing the faulting instruction.
 152     rerun_to_main
 153     gdb_test "handle SIGSEGV nostop print pass" "" "${name}; pass SIGSEGV"
 154     gdb_test "continue" "keeper.*" "${name}; continue to keeper"
 155     gdb_test "handle SIGSEGV stop print nopass" "" "${name}; nopass SIGSEGV"
 156
 157     # Insert all the breakpoints.  To avoid the need to step over
 158     # these instructions, this is delayed until after the keeper has
 159     # been reached.
 160     for {set i 0} {$i < [llength $args]} {incr i} {
 161         gdb_test "break [lindex $args $i]" "Breakpoint.*" \
 162             "${name}; set breakpoint $i of [llength $args]"
 163     }
 164
 165     # Single step our way out of the keeper, through the signal
 166     # trampoline, and back to the instruction that faulted.
 167     set test "${name}; stepi out of handler"
 168     gdb_test_multiple "stepi" "$test" {
 169         -re "keeper.*$gdb_prompt $" {
 170             send_gdb "stepi\n"
 171             exp_continue
 172         }
 173         -re "signal handler.*$gdb_prompt $" {
 174             send_gdb "stepi\n"
 175             exp_continue
 176         }
 177         -re "Program received signal SIGSEGV.*$gdb_prompt $" {
 178             kfail gdb/1702 "$test (executed fault insn)"
 179         }
 180         -re "Breakpoint.*pc *[at_segv] .*bowler.*$gdb_prompt $" {
 181             pass "$test (at breakpoint)"
 182         }
 183         -re "Breakpoint.*pc *[after_segv] .*bowler.*$gdb_prompt $" {
 184             kfail gdb/1702 "$test (executed breakpoint)"
 185         }
 186         -re "pc *[at_segv] .*bowler.*$gdb_prompt $" {
 187             pass "$test"
 188         }
 189         -re "pc *[after_segv] .*bowler.*$gdb_prompt $" {
 190             kfail gdb/1702 "$test (skipped fault insn)"
 191         }
 192         -re "pc *0x\[a-z0-9\]* .*bowler.*$gdb_prompt $" {
 193             kfail gdb/1702 "$test (corrupt pc)"
 194         }
 195     }
 196
 197     # Clear any breakpoints
 198     for {set i 0} {$i < [llength $args]} {incr i} {
 199         gdb_test "clear [lindex $args $i]" "Deleted .*" \
 200             "${name}; clear breakpoint $i of [llength $args]"
 201     }
 202 }
 203
 204 # Let a signal handler exit, returning to a breakpoint instruction
 205 # inserted at the original fault instruction.  Check that the
 206 # breakpoint is hit, and that single stepping off that breakpoint
 207 # executes the underlying fault instruction causing a SIGSEGV.
 208
 209 proc cont_out { name args } {
 210     global gdb_prompt
 211
 212     # Set SIGSEGV to pass+nostop and then run the inferior all the way
 213     # through to the signal handler.  With the handler is reached,
 214     # disable SIGSEGV, ensuring that further signals stop the
 215     # inferior.  Stops a SIGSEGV infinite loop when a broke system
 216     # keeps re-executing the faulting instruction.
 217     rerun_to_main
 218     gdb_test "handle SIGSEGV nostop print pass" "" "${name}; pass SIGSEGV"
 219     gdb_test "continue" "keeper.*" "${name}; continue to keeper"
 220     gdb_test "handle SIGSEGV stop print nopass" "" "${name}; nopass SIGSEGV"
 221
 222     # Insert all the breakpoints.  To avoid the need to step over
 223     # these instructions, this is delayed until after the keeper has
 224     # been reached.  Always set a breakpoint at the signal trampoline
 225     # instruction.
 226     set args [concat $args "*[at_segv]"]
 227     for {set i 0} {$i < [llength $args]} {incr i} {
 228         gdb_test "break [lindex $args $i]" "Breakpoint.*" \
 229             "${name}; set breakpoint $i  of [llength $args]"
 230     }
 231
 232     # Let the handler return, it should "appear to hit" the breakpoint
 233     # inserted at the faulting instruction.  Note that the breakpoint
 234     # instruction wasn't executed, rather the inferior was SIGTRAPed
 235     # with the PC at the breakpoint.
 236     gdb_test "continue" "Breakpoint.*pc *[at_segv] .*" \
 237         "${name}; continue to breakpoint at fault"
 238
 239     # Now single step the faulted instrction at that breakpoint.
 240     gdb_test "stepi" \
 241         "Program received signal SIGSEGV.*pc *[at_segv] .*" \
 242         "${name}; stepi fault"
 243
 244     # Clear any breakpoints
 245     for {set i 0} {$i < [llength $args]} {incr i} {
 246         gdb_test "clear [lindex $args $i]" "Deleted .*" \
 247             "${name}; clear breakpoint $i of [llength $args]"
 248     }
 249
 250 }
 251
 252
 253
 254 # Try to confuse DECR_PC_AFTER_BREAK architectures by scattering
 255 # breakpoints around the faulting address.  In all cases the inferior
 256 # should single-step out of the signal trampoline halting (but not
 257 # executing) the fault instruction.
 258
 259 stepi_out "stepi"
 260 stepi_out "stepi bp before segv" "*[before_segv]"
 261 stepi_out "stepi bp at segv" "*[at_segv]"
 262 stepi_out "stepi bp before and at segv" "*[at_segv]" "*[before_segv]"
 263
 264
 265 # Try to confuse DECR_PC_AFTER_BREAK architectures by scattering
 266 # breakpoints around the faulting address.  In all cases the inferior
 267 # should exit the signal trampoline halting at the breakpoint that
 268 # replaced the fault instruction.
 269 cont_out "cont"
 270 cont_out "cont bp after segv" "*[before_segv]"
 271 cont_out "cont bp before and after segv" "*[before_segv]" "*[after_segv]"