gdb/testsuite/gdb.threads/detach-step-over.exp

   1 # Copyright 2021 Free Software Foundation, Inc.
   2
   3 # This program is free software; you can redistribute it and/or modify
   4 # it under the terms of the GNU General Public License as published by
   5 # the Free Software Foundation; either version 3 of the License, or
   6 # (at your option) any later version.
   7 #
   8 # This program is distributed in the hope that it will be useful,
   9 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 # GNU General Public License for more details.
  12 #
  13 # You should have received a copy of the GNU General Public License
  14 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15
  16 # Test detaching from a process that is running and has threads
  17 # constantly hitting a breakpoint and stepping over it, in all
  18 # combinations of:
  19 #
  20 #  - maint target non-stop off/on
  21 #  - set non-stop on/off
  22 #  - displaced stepping on/off
  23 #
  24 # This stresses the edge cases of detaching while a displaced step or
  25 # an in-line step over are in progress.
  26 #
  27 # A fail mode is that the inferior process dies after being detached.
  28 # This can happen because e.g.:
  29 #
  30 # - GDB leaves a breakpoint installed behind, or
  31 #
  32 # - GDB leaves a thread running in the displaced step scratch buffer.
  33 #   With no debugger around to run the finish step, the thread runs
  34 #   off of the scratch buffer, with undefined results.
  35 #
  36 # To exercise this, the testcase reattaches to the process shortly
  37 # after detaching, ensuring the process is still alive and well.
  38 #
  39 # In addition, since GDB may pause threads of all processes for
  40 # stepping over a breakpoint, it needs to re-resume all threads if it
  41 # detaches from the process that was just stepping over the
  42 # breakpoint.  To ensure that, the testcase actually runs a second
  43 # process at the same time as the one that is used to test detaching.
  44 # After the first process is detached, the testcase sends a SIGUSR1 to
  45 # the second process.  If threads failed to be resumed, then the
  46 # SIGUSR1 is never reported to the user, resulting in timeout.  The
  47 # threads of this second process will also be constantly stepping over
  48 # a breakpoint, which has helped with exposing further corner case
  49 # bugs.
  50
  51 if {![can_spawn_for_attach]} {
  52     return 0
  53 }
  54
  55 standard_testfile
  56
  57 set bp_lineno [gdb_get_line_number "Set breakpoint here"]
  58
  59 # The test proper.  See description above.
  60 proc test {condition_eval target_non_stop non_stop displaced} {
  61     global binfile srcfile
  62     global gdb_prompt
  63     global decimal
  64     global bp_lineno
  65     global GDBFLAGS
  66
  67     # Number of threads started by the program.
  68     set n_threads 10
  69
  70     save_vars { GDBFLAGS } {
  71         append GDBFLAGS " -ex \"maint set target-non-stop $target_non_stop\""
  72         append GDBFLAGS " -ex \"set non-stop $non_stop\""
  73         append GDBFLAGS " -ex \"set displaced $displaced\""
  74         append GDBFLAGS " -ex \"set schedule-multiple on\""
  75         clean_restart $binfile
  76     }
  77
  78     set test_spawn_id [spawn_wait_for_attach $binfile]
  79     set testpid [spawn_id_get_pid $test_spawn_id]
  80
  81     set any "\[^\r\n\]*"
  82
  83     gdb_test "add-inferior" "Added inferior 2.*"
  84     gdb_test "inferior 2" "Switching to .*"
  85
  86     gdb_load $binfile
  87     if ![runto setup_done] then {
  88         fail "can't run to setup_done"
  89         kill_wait_spawned_process $test_spawn_id
  90         return
  91     }
  92
  93     gdb_test_no_output "set breakpoint condition-evaluation $condition_eval"
  94
  95     # Get the PID of the test process.
  96     set pid_inf2 ""
  97     gdb_test_multiple "p mypid" "get pid of inferior 2" {
  98         -re " = ($decimal)\r\n$gdb_prompt $" {
  99             set pid_inf2 $expect_out(1,string)
 100             pass $gdb_test_name
 101         }
 102     }
 103
 104     set attempts 3
 105     for {set attempt 1} { $attempt <= $attempts } { incr attempt } {
 106         with_test_prefix "iter $attempt" {
 107             gdb_test "inferior 1" "Switching to .*"
 108
 109             with_timeout_factor 2 {
 110                 set attached 0
 111                 set saw_attaching 0
 112                 set eperm 0
 113                 set test "attach"
 114                 gdb_test_multiple "attach $testpid" $test {
 115                     -re "Attaching to program.*process $testpid\r\n" {
 116                         set saw_attaching 1
 117                         exp_continue
 118                     }
 119                     -re "new threads in iteration" {
 120                         # Seen when "set debug libthread_db" is on.
 121                         exp_continue
 122                     }
 123                     -re "Reading symbols from|Expanding full symbols from" {
 124                         # Prevent -readnow timeout.
 125                         exp_continue
 126                     }
 127                     -re "is a zombie - the process has already terminated.*$gdb_prompt " {
 128                         fail $gdb_test_name
 129                     }
 130                     -re "Unable to attach: .*$gdb_prompt " {
 131                         fail $gdb_test_name
 132                     }
 133                     -re "\r\n$gdb_prompt " {
 134                         if { $saw_attaching } {
 135                             set attached 1
 136                             pass $test
 137                         } else {
 138                             fail $test
 139                         }
 140                     }
 141                 }
 142             }
 143
 144             if {!$attached} {
 145                 kill_wait_spawned_process $test_spawn_id
 146                 return
 147             }
 148
 149             if {$non_stop} {
 150                 # In non-stop, we will see one stop per thread after
 151                 # the prompt.
 152                 set stops 0
 153                 set tid_re "$::decimal\.$::decimal"
 154                 set test "seen all stops"
 155                 for {set thread 1} { $thread <= $n_threads } { incr thread } {
 156                     if {[gdb_test_multiple "" $test {
 157                         -re "Thread ${tid_re} ${any} stopped" {
 158                             incr stops
 159                         }
 160                     }] != 0} {
 161                         break
 162                     }
 163                 }
 164
 165                 # If we haven't seen all stops, then the
 166                 # gdb_test_multiple in the loop above will have
 167                 # already issued a FAIL.
 168                 if {$stops != $n_threads} {
 169                     kill_wait_spawned_process $test_spawn_id
 170                     return
 171                 }
 172                 pass $test
 173             }
 174
 175             # Set threads stepping over a breakpoint continuously.
 176             gdb_test "break $srcfile:$bp_lineno if 0" "Breakpoint.*" \
 177                 "break LOC if 0"
 178
 179             if {$attempt < $attempts} {
 180                 # Kick the time out timer for another round.
 181                 gdb_test "print again = 1" " = 1" "reset timer in the inferior"
 182                 # Show the time we had left in the logs, in case
 183                 # something goes wrong.
 184                 gdb_test "print seconds_left" " = .*"
 185             }
 186
 187             if {$non_stop} {
 188                 set cont_cmd "continue -a &"
 189             } else {
 190                 set cont_cmd "continue &"
 191             }
 192
 193             set cont_cmd_re [string_to_regexp $cont_cmd]
 194             gdb_test_multiple $cont_cmd "" {
 195                 -re "^$cont_cmd_re\r\nContinuing\.\r\n$gdb_prompt " {
 196                     pass $gdb_test_name
 197                 }
 198             }
 199
 200             # Wait a bit, to give time for the threads to hit the
 201             # breakpoint.
 202             sleep 1
 203
 204             set running_count 0
 205             set interrupted 0
 206             gdb_test_multiple "info threads" "all threads running" {
 207                 -re "\\(running\\)" {
 208                     incr running_count
 209                     exp_continue
 210                 }
 211                 -re "Cannot execute this command while the target is running.*$gdb_prompt $" {
 212                     # Testing against a remote server that doesn't do
 213                     # non-stop mode.  Explicitly interrupt.  This
 214                     # doesn't test the same code paths in GDB, but
 215                     # it's still something.
 216                     set interrupted 1
 217                     gdb_test_multiple "interrupt" "" {
 218                         -re "$gdb_prompt " {
 219                             gdb_test_multiple "" $gdb_test_name {
 220                                 -re "received signal SIGINT, Interrupt" {
 221                                     pass $gdb_test_name
 222                                 }
 223                             }
 224                         }
 225                     }
 226                 }
 227                 -re "$gdb_prompt $" {
 228                     gdb_assert {$running_count == ($n_threads + 1) * 2} $gdb_test_name
 229                 }
 230             }
 231
 232             gdb_test "detach" "Detaching from.*"
 233
 234             if {!$interrupted} {
 235                 # Now test whether inferior 2's thread were really left
 236                 # running.  Currently an inline step-over stops all
 237                 # threads of all processes.  If detach aborts such a step
 238                 # over, then threads of other inferiors should be
 239                 # re-resumed.  Test for that by sending a signal to
 240                 # inferior 2.
 241                 remote_exec target "kill -SIGUSR1 ${pid_inf2}"
 242
 243                 gdb_test_multiple "" "stop with SIGUSR1" {
 244                     -re "received signal SIGUSR1" {
 245                         pass $gdb_test_name
 246                     }
 247                 }
 248             }
 249
 250             delete_breakpoints
 251         }
 252     }
 253     kill_wait_spawned_process $test_spawn_id
 254 }
 255
 256 # The test program exits after a while, in case GDB crashes.  Make it
 257 # wait at least as long as we may wait before declaring a time out
 258 # failure.
 259 set options { "additional_flags=-DTIMEOUT=$timeout" debug pthreads }
 260
 261 if {[prepare_for_testing "failed to prepare" $testfile $srcfile $options] == -1} {
 262     return -1
 263 }
 264
 265 if ![runto_main] {
 266     return -1
 267 }
 268
 269 # Probe support for "set breakpoint condition-evaluation target".
 270 # This setting influences who steps over the breakpoint, the (remote)
 271 # target (e.g. gdbserver) or gdb, thus exposing issues on either the
 272 # target or gdb.
 273 set supports_condition_eval_target 1
 274 set cmd "set breakpoint condition-evaluation target"
 275 gdb_test_multiple $cmd "probe condition-evaluation target support" {
 276     -re "warning: Target does not support breakpoint condition evaluation.\r\nUsing host evaluation mode instead.\r\n$gdb_prompt $" {
 277         # Target doesn't support breakpoint condition evaluation on
 278         # its side.
 279         set supports_condition_eval_target 0
 280         pass $gdb_test_name
 281     }
 282     -re "^$cmd\r\n$gdb_prompt $" {
 283         pass $gdb_test_name
 284     }
 285 }
 286
 287 foreach_with_prefix breakpoint-condition-evaluation {"host" "target"} {
 288     if {!$supports_condition_eval_target && ${breakpoint-condition-evaluation} == "target"} {
 289         continue
 290     }
 291
 292     foreach_with_prefix target-non-stop {"off" "on"} {
 293         foreach_with_prefix non-stop {"off" "on"} {
 294             if {${non-stop} && !${target-non-stop}} {
 295                 # "set non-stop" overrides "maint set
 296                 # target-non-stop", no use testing this combination.
 297                 continue
 298             }
 299
 300             foreach_with_prefix displaced {"off" "auto"} {
 301                 test ${breakpoint-condition-evaluation} ${target-non-stop} ${non-stop} ${displaced}
 302             }
 303         }
 304     }
 305 }