gdb/testsuite/gdb.base/sigstep.exp

   1 # Copyright 2004-2014 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
  17 # The program sigstep.c creates a very simple backtrace containing one
  18 # signal handler and signal trampoline.  A flag is set and then the
  19 # handler returns.  This is repeated at infinitum.
  20
  21 # This test runs the program up to the signal handler, and then
  22 # attempts to step/next out of the handler and back into main.
  23
  24 if [target_info exists gdb,nosignals] {
  25     verbose "Skipping sigstep.exp because of nosignals."
  26     continue
  27 }
  28
  29
  30 standard_testfile
  31
  32 if {[build_executable $testfile.exp $testfile $srcfile debug]} {
  33     untested $testfile.exp
  34     return -1
  35 }
  36
  37 set clear_done [gdb_get_line_number {done = 0}]
  38 set infinite_loop [gdb_get_line_number {while (!done)}]
  39 set other_handler_location [gdb_get_line_number "other handler location"]
  40
  41 # Restart GDB, set a display showing $PC, and run to main.
  42
  43 proc restart {} {
  44     global binfile
  45
  46     clean_restart $binfile
  47
  48     gdb_test "display/i \$pc"
  49
  50     runto_main
  51 }
  52
  53 # Pass all the alarms straight through (but verbosely)
  54 # gdb_test "handle SIGALRM print pass nostop"
  55 # gdb_test "handle SIGVTALRM print pass nostop"
  56 # gdb_test "handle SIGPROF print pass nostop"
  57
  58 # Run to the signal handler, validate the backtrace.
  59
  60 proc validate_backtrace {} {
  61     with_test_prefix "validate backtrace" {
  62         restart
  63
  64         gdb_test "break handler"
  65         gdb_test "continue" ".* handler .*" "continue to stepi handler"
  66         gdb_test_sequence "bt" "backtrace for nexti" {
  67             "\[\r\n\]+.0 \[^\r\n\]* handler "
  68             "\[\r\n\]+.1  .signal handler called."
  69             "\[\r\n\]+.2 \[^\r\n\]* main "
  70         }
  71     }
  72 }
  73
  74 validate_backtrace
  75
  76 # Goes to handler using ENTER_CMD, runs IN_HANDLER while in the signal
  77 # hander, and then steps out of the signal handler using EXIT_CMD.
  78
  79 proc advance { enter_cmd in_handler_prefix in_handler exit_cmd } {
  80     global gdb_prompt inferior_exited_re
  81     global clear_done other_handler_location
  82
  83     set prefix "$enter_cmd to handler, $in_handler_prefix in handler, $exit_cmd from handler"
  84
  85     with_test_prefix $prefix {
  86         restart
  87
  88         # Get us into the handler
  89         if { $enter_cmd == "continue" } {
  90             gdb_test "break handler"
  91         } else {
  92             gdb_test "handle SIGALRM print pass stop"
  93             gdb_test "handle SIGVTALRM print pass stop"
  94             gdb_test "continue" "Program received signal.*" "continue to signal"
  95         }
  96         gdb_test "$enter_cmd" ".*handler .*" "$enter_cmd to handler"
  97
  98         delete_breakpoints
  99
 100         uplevel 1 $in_handler
 101
 102         if { $exit_cmd == "continue" } {
 103             gdb_test "break $clear_done" ".*" "break clear done"
 104         }
 105
 106         set test "leave handler"
 107         gdb_test_multiple "$exit_cmd" "${test}" {
 108             -re "Could not insert single-step breakpoint.*$gdb_prompt $" {
 109                 setup_kfail gdb/8841 "sparc*-*-openbsd*"
 110                 fail "$test (could not insert single-step breakpoint)"
 111             }
 112             -re "done = 1;.*${gdb_prompt} $" {
 113                 send_gdb "$exit_cmd\n"
 114                 exp_continue -continue_timer
 115             }
 116             -re "\} .. handler .*${gdb_prompt} $" {
 117                 send_gdb "$exit_cmd\n"
 118                 exp_continue -continue_timer
 119             }
 120             -re "$inferior_exited_re normally.*${gdb_prompt} $" {
 121                 setup_kfail gdb/8744 powerpc-*-*bsd*
 122                 fail "$test (program exited)"
 123             }
 124             -re "(while ..done|done = 0).*${gdb_prompt} $" {
 125                 # After stepping out of a function /r signal-handler, GDB will
 126                 # advance the inferior until it is at the first instruction of
 127                 # a code-line.  While typically things return to the middle of
 128                 # the "while..." (and hence GDB advances the inferior to the
 129                 # "return..." line) it is also possible for the return to land
 130                 # on the first instruction of "while...".  Accept both cases.
 131                 pass "$test"
 132             }
 133         }
 134     }
 135 }
 136
 137 # Map of PREFIX => "things to do within the signal handler", for the
 138 # advance tests.
 139
 140 set in_handler_map {
 141     "nothing" {
 142     }
 143     "si+advance" {
 144         # Advance to the second location in handler.
 145         gdb_test "si" "handler.*" "si in handler"
 146
 147         set test "advance in handler"
 148         gdb_test_multiple "advance $other_handler_location" $test {
 149             -re "Program received signal SIGTRAP.*$gdb_prompt $" {
 150                 # On some versions of Linux (observed on
 151                 # 3.16.4-200.fc20.x86_64), using PTRACE_SINGLESTEP+sig
 152                 # to step into a signal handler, and then issuing
 153                 # another PTRACE_SINGLESTEP within the handler ends up
 154                 # with $eflags.TF mistakenly set, which results in
 155                 # subsequent PTRACE_CONTINUEs trapping after each
 156                 # insn.
 157                 if {$enter_cmd != "continue"} {
 158                     setup_xfail "x86_64-*-linux*" gdb/17511
 159                 }
 160                 fail "$test (spurious SIGTRAP)"
 161                 return
 162             }
 163             -re "other handler location.*$gdb_prompt $" {
 164                 pass $test
 165             }
 166         }
 167     }
 168 }
 169
 170 # Check that we can step/next/continue, etc. our way in and out of a
 171 # signal handler.  Also test that we can step, and run to a breakpoint
 172 # within the handler.
 173
 174 foreach enter_cmd { "stepi" "nexti" "step" "next" "continue" } {
 175     if { $enter_cmd != "continue" && ![can_single_step_to_signal_handler] } {
 176         continue
 177     }
 178
 179     foreach exit_cmd { "step" "next" "continue" } {
 180         foreach {in_handler_prefix in_handler} $in_handler_map {
 181             advance $enter_cmd $in_handler_prefix $in_handler $exit_cmd
 182         }
 183     }
 184 }
 185
 186 proc advancei { cmd } {
 187     global gdb_prompt inferior_exited_re
 188
 189     with_test_prefix "$cmd from handleri" {
 190         restart
 191
 192         # Get us into the handler.
 193         gdb_test "break handler"
 194         gdb_test "continue" ".* handler .*" "continue to handler"
 195
 196         set program_exited 0
 197         set test "leave handler"
 198         gdb_test_multiple "$cmd" "${test}" {
 199             -re "Cannot insert breakpoint 0.*${gdb_prompt} $" {
 200                 # Some platforms use a special read-only page for signal
 201                 # trampolines.  We can't set a breakpoint there, and we
 202                 # don't gracefully fall back to single-stepping.
 203                 setup_kfail gdb/8841 "i?86-*-linux*"
 204                 setup_kfail gdb/8841 "*-*-openbsd*"
 205                 fail "$test (could not set breakpoint)"
 206                 return
 207             }
 208             -re "Could not insert single-step breakpoint.*$gdb_prompt $" {
 209                 setup_kfail gdb/8841 "sparc*-*-openbsd*"
 210                 fail "$test (could not insert single-step breakpoint)"
 211             }
 212             -re "Breakpoint \[0-9\]*, handler .*${gdb_prompt} $" {
 213                 fail "$test (hit breakpoint again)"
 214             }
 215             -re "done = 1;.*${gdb_prompt} $" {
 216                 send_gdb "$cmd\n"
 217                 exp_continue -continue_timer
 218             }
 219             -re "\} .. handler .*${gdb_prompt} $" {
 220                 send_gdb "$cmd\n"
 221                 exp_continue -continue_timer
 222             }
 223             -re "signal handler called.*${gdb_prompt} $" {
 224                 pass "$test"
 225             }
 226             -re "main .*${gdb_prompt} $" {
 227                 fail "$test (in main)"
 228             }
 229             -re "$inferior_exited_re normally.*${gdb_prompt} $" {
 230                 fail "$test (program exited)"
 231                 set program_exited 1
 232             }
 233             -re "Make handler return now.*y or n. $" {
 234                 send_gdb "y\n"
 235                 exp_continue -continue_timer
 236             }
 237         }
 238
 239         set test "leave signal trampoline"
 240         gdb_test_multiple "$cmd" "${test}" {
 241             -re "while .*${gdb_prompt} $" {
 242                 pass "$test (in main)"
 243             }
 244             -re "signal handler called.*${gdb_prompt} $" {
 245                 send_gdb "$cmd\n"
 246                 exp_continue -continue_timer
 247             }
 248             -re "return .*${gdb_prompt} $" {
 249                 fail "$test (stepped)"
 250             }
 251             -re "Make .*frame return now.*y or n. $" {
 252                 send_gdb "y\n"
 253                 exp_continue -continue_timer
 254             }
 255             -re "$inferior_exited_re normally.*${gdb_prompt} $" {
 256                 kfail gdb/8744 "$test (program exited)"
 257                 set program_exited 1
 258             }
 259             -re "The program is not being run.*${gdb_prompt} $" {
 260                 if { $program_exited } {
 261                     # Previously kfailed with an exit
 262                     pass "$test (the program is not being run)"
 263                 } else {
 264                     fail "$test (the program is not being run)"
 265                 }
 266             }
 267         }
 268     }
 269 }
 270
 271 # Check that we can step our way out of a signal handler, using
 272 # commands that first step out to the signal trampoline, and then out
 273 # to the mainline code.
 274
 275 foreach cmd {"stepi" "nexti" "finish" "return"} {
 276     advancei $cmd
 277 }
 278
 279 # Check that we can step/next our way into / over a signal handler.
 280
 281 # There are at least the following cases: breakpoint @pc VS breakpoint
 282 # in handler VS step / next / continue.
 283
 284
 285 # Try stepping when there's a signal pending, and a breakpoint at the
 286 # handler.  Should step into the signal handler.
 287
 288 proc skip_to_handler { cmd } {
 289     global infinite_loop
 290
 291     with_test_prefix "$cmd to handler" {
 292         restart
 293         # Use the real-time itimer, as otherwize the process never gets
 294         # enough time to expire the timer.
 295         gdb_test_no_output "set itimer = itimer_real"
 296
 297         # Advance to the infinite loop.
 298         gdb_test "advance $infinite_loop" ".*" "advance to infinite loop"
 299
 300         # Make the signal pending.
 301         sleep 1
 302
 303         # Insert the handler breakpoint.
 304         gdb_test "break handler" ".*" "break handler"
 305
 306         # Step into the handler.
 307         gdb_test "$cmd" " handler .*" "performing $cmd"
 308     }
 309 }
 310
 311 foreach cmd {"step" "next" "continue"} {
 312     skip_to_handler $cmd
 313 }
 314
 315 # Try stepping when there's a signal pending, and a breakpoint at the
 316 # handler's entry-point.  Should step into the signal handler stopping
 317 # at the entry-point.
 318
 319 # Some systems (e.x., GNU/Linux as of 2004-08-30), when delivering a
 320 # signal, resume the process at the first instruction of the signal
 321 # handler and not the first instruction of the signal trampoline.  The
 322 # stack is constructed such that the signal handler still appears to
 323 # have been called by the trampoline code.  This test checks that it
 324 # is possible to stop the inferior, even at that first instruction.
 325
 326 proc skip_to_handler_entry { cmd } {
 327     global infinite_loop
 328
 329     with_test_prefix "$cmd to handler entry" {
 330         restart
 331         # Use the real-time itimer, as otherwize the process never gets
 332         # enough time to expire the timer.
 333         gdb_test_no_output "set itimer = itimer_real"
 334
 335         # Advance to the infinite loop.
 336         gdb_test "advance $infinite_loop" ".*" "advance to infinite loop"
 337
 338         # Make the signal pending.
 339         sleep 1
 340
 341         # Insert / remove the handler breakpoint.
 342         gdb_test "break *handler" ".*" "break handler"
 343         gdb_test "$cmd" " handler .*" "performing $cmd"
 344     }
 345 }
 346
 347 foreach cmd {"stepi" "nexti" "step" "next" "continue"} {
 348     skip_to_handler_entry $cmd
 349 }
 350
 351 # Get the address of where a single-step should land.
 352
 353 proc get_next_pc {test} {
 354     global gdb_prompt
 355     global hex
 356
 357     set next ""
 358     gdb_test_multiple "x/2i \$pc" $test {
 359         -re "$hex .*:\[^\r\n\]+\r\n\[ \]+($hex).*\.\r\n$gdb_prompt $" {
 360             set next $expect_out(1,string)
 361             pass $test
 362         }
 363     }
 364
 365     return $next
 366 }
 367
 368 # Test that the command skipped over the handler.
 369
 370 proc test_skip_handler {cmd} {
 371     if {$cmd == "stepi" || $cmd == "nexti"} {
 372         set next_pc [get_next_pc "get next PC"]
 373         gdb_test "$cmd" "dummy = 0.*" "performing $cmd"
 374         gdb_test "p /x \$pc" " = $next_pc" "advanced"
 375     } else {
 376         gdb_test "$cmd" "done = 0.*" "performing $cmd"
 377     }
 378 }
 379
 380 # Try stepping when there's a signal pending but no breakpoints.
 381 # Should skip the handler advancing to the next line.
 382
 383 proc skip_over_handler { cmd } {
 384     global infinite_loop
 385     global clear_done
 386
 387     with_test_prefix "$cmd over handler" {
 388         restart
 389         # Use the real-time itimer, as otherwize the process never gets
 390         # enough time to expire the timer.
 391         gdb_test_no_output "set itimer = itimer_real"
 392
 393         gdb_test "break $clear_done" ".*" "break clear done"
 394
 395         # Advance to the infinite loop.
 396         gdb_test "advance $infinite_loop" ".*" "advance to infinite loop"
 397
 398         # Make the signal pending.
 399         sleep 1
 400
 401         test_skip_handler $cmd
 402     }
 403 }
 404
 405 foreach cmd {"stepi" "nexti" "step" "next" "continue"} {
 406     skip_over_handler $cmd
 407 }
 408
 409 # Try stepping when there's a signal pending, a pre-existing
 410 # breakpoint at the current instruction, and a breakpoint in the
 411 # handler.  Should advance to the signal handler.
 412
 413 proc breakpoint_to_handler { cmd } {
 414     global infinite_loop
 415
 416     with_test_prefix "$cmd on breakpoint, to handler" {
 417         restart
 418         # Use the real-time itimer, as otherwize the process never gets
 419         # enough time to expire the timer.
 420         gdb_test_no_output "set itimer = itimer_real"
 421
 422         gdb_test "break $infinite_loop" ".*" "break infinite loop"
 423         gdb_test "break handler" ".*" "break handler"
 424
 425         # Continue to the infinite loop.
 426         gdb_test "continue" "while ..done.*" "continue to infinite loop"
 427
 428         # Make the signal pending.
 429         sleep 1
 430
 431         gdb_test "$cmd" " handler .*" "performing $cmd"
 432     }
 433 }
 434
 435 foreach cmd {"step" "next" "continue"} {
 436     breakpoint_to_handler $cmd
 437 }
 438
 439 # Try stepping when there's a signal pending, and a breakpoint at the
 440 # handler's entry instruction and a breakpoint at the current
 441 # instruction.  Should step into the signal handler and breakpoint at
 442 # that entry instruction.
 443
 444 # Some systems (e.x., GNU/Linux as of 2004-08-30), when delivering a
 445 # signal, resume the process at the first instruction of the signal
 446 # handler and not the first instruction of the signal trampoline.  The
 447 # stack is constructed such that the signal handler still appears to
 448 # have been called by the trampoline code.  This test checks that it
 449 # is possible to stop the inferior, even at that first instruction.
 450
 451 proc breakpoint_to_handler_entry { cmd } {
 452     global infinite_loop
 453
 454     with_test_prefix "$cmd on breakpoint, to handler entry" {
 455         restart
 456         # Use the real-time itimer, as otherwize the process never gets
 457         # enough time to expire the timer.
 458         gdb_test_no_output "set itimer = itimer_real"
 459
 460         gdb_test "break $infinite_loop" ".*" "break infinite loop"
 461         gdb_test "break *handler" ".*" "break handler"
 462
 463         # Continue to the infinite loop.
 464         gdb_test "continue" "while ..done.*" "continue to infinite loop"
 465
 466         # Make the signal pending.
 467         sleep 1
 468
 469         gdb_test "$cmd" " handler .*" "performing $cmd"
 470     }
 471 }
 472
 473 foreach cmd {"step" "next" "continue"} {
 474     breakpoint_to_handler_entry $cmd
 475 }
 476
 477 # Try stepping when there's a signal pending, and a pre-existing
 478 # breakpoint at the current instruction, and no breakpoint in the
 479 # handler.  Should advance to the next line/instruction.  If SW_WATCH
 480 # is true, set a software watchpoint, which exercises stepping the
 481 # breakpoint instruction while delivering a signal at the same time.
 482 # If NO_HANDLER, arrange for the signal's handler be SIG_IGN, thus
 483 # when the software watchpoint is also set, testing stepping a
 484 # breakpoint instruction and immediately triggering the breakpoint
 485 # (exercises adjust_pc_after_break logic).
 486
 487 proc breakpoint_over_handler { cmd with_sw_watch no_handler } {
 488     global infinite_loop
 489     global clear_done
 490
 491     set prefix "$cmd on breakpoint, skip handler"
 492     if { $with_sw_watch } {
 493         append prefix ", with sw-watchpoint"
 494     }
 495     if { $no_handler } {
 496         append prefix ", no handler"
 497     }
 498
 499     with_test_prefix "$prefix" {
 500         restart
 501         # Use the real-time itimer, as otherwize the process never gets
 502         # enough time to expire the timer.
 503         gdb_test_no_output "set itimer = itimer_real"
 504
 505         if {$no_handler} {
 506             gdb_test "print no_handler = 1" " = 1" \
 507                 "set no_handler"
 508         }
 509
 510         gdb_test "break $infinite_loop" ".*" "break infinite loop"
 511
 512         gdb_test "break $clear_done" ".*" "break clear done"
 513
 514         # Continue to the infinite loop
 515         gdb_test "continue" "while ..done.*" "continue to infinite loop"
 516
 517         # Make the signal pending
 518         sleep 1
 519
 520         if { $with_sw_watch } {
 521             # A watchpoint on a convenience variable is always a
 522             # software watchpoint.
 523             gdb_test "watch \$convenience" "Watchpoint .*: \\\$convenience"
 524         }
 525
 526         if {$no_handler} {
 527             # With no handler, we need to set the global ourselves
 528             # manually.
 529             gdb_test "print done = 1" " = 1" "set done"
 530         }
 531
 532         test_skip_handler $cmd
 533     }
 534 }
 535
 536 foreach cmd {"stepi" "nexti" "step" "next" "continue"} {
 537     foreach with_sw_watch {0 1} {
 538         foreach no_handler {0 1} {
 539             breakpoint_over_handler $cmd $with_sw_watch $no_handler
 540         }
 541     }
 542 }