gdb/testsuite/gdb.threads/vfork-multi-thread.exp

   1 # Copyright 2022 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 that a multi-threaded program doing a vfork doesn't miss breakpoints.
  17 #
  18 # When a program vforks, its address space is shared with the parent.  When we
  19 # detach a vfork child, we must keep breakpoints out of that shared address space
  20 # until the child either exits or execs, so that the child does not hit a
  21 # breakpoint while out of GDB's control.  During that time, threads from
  22 # the parent must be held stopped, otherwise they could miss breakpoints.
  23 #
  24 # The thread that did the vfork is suspended by the kernel, so it's not a
  25 # concern.  The other threads need to be manually stopped by GDB and resumed
  26 # once the vfork critical region is done.
  27 #
  28 # This test spawns one thread that calls vfork.  Meanwhile, the main thread
  29 # crosses a breakpoint.  A buggy GDB would let the main thread run while
  30 # breakpoints are removed, so the main thread would miss the breakpoint and run
  31 # until exit.
  32
  33 standard_testfile
  34
  35 if { [build_executable "failed to prepare" ${testfile} ${srcfile} {debug pthreads}] } {
  36     return
  37 }
  38
  39 set any "\[^\r\n\]*"
  40
  41 # A bunch of util procedures to continue an inferior to an expected point.
  42
  43 proc continue_to_parent_breakpoint {} {
  44     gdb_test "continue" \
  45         "hit Breakpoint .* should_break_here .*" \
  46         "continue parent to breakpoint"
  47 }
  48
  49 proc continue_to_parent_end {} {
  50     gdb_test "continue" "Inferior 1.*exited with code 06.*" \
  51         "continue parent to end"
  52 }
  53
  54 # Run the test with the given GDB settings.
  55
  56 proc do_test { target-non-stop non-stop follow-fork-mode detach-on-fork schedule-multiple } {
  57     save_vars { ::GDBFLAGS } {
  58         append ::GDBFLAGS " -ex \"maintenance set target-non-stop ${target-non-stop}\""
  59         append ::GDBFLAGS " -ex \"set non-stop ${non-stop}\""
  60         clean_restart ${::binfile}
  61     }
  62
  63     gdb_test_no_output "set follow-fork-mode ${follow-fork-mode}"
  64     gdb_test_no_output "set detach-on-fork ${detach-on-fork}"
  65     gdb_test_no_output "set schedule-multiple ${schedule-multiple}"
  66
  67     # The message about thread 2 of inferior 1 exiting happens at a somewhat
  68     # unpredictable moment, it's simpler to silence it than to try to match it.
  69     gdb_test_no_output "set print thread-events off"
  70
  71     if { ![runto_main] } {
  72         return
  73     }
  74
  75     # The main thread is expected to hit this breakpoint.
  76     gdb_test "break should_break_here" "Breakpoint $::decimal at .*"
  77
  78     continue_to_parent_breakpoint
  79     continue_to_parent_end
  80 }
  81
  82 # We only test with follow-fork-mode=parent and detach-on-fork=on at the
  83 # moment, but the loops below are written to make it easy to add other values
  84 # on these axes in the future.
  85
  86 foreach_with_prefix target-non-stop {auto on off} {
  87     foreach_with_prefix non-stop {off on} {
  88         foreach_with_prefix follow-fork-mode {parent} {
  89             foreach_with_prefix detach-on-fork {on} {
  90                 foreach_with_prefix schedule-multiple {off on} {
  91                     do_test ${target-non-stop} ${non-stop} ${follow-fork-mode} ${detach-on-fork} ${schedule-multiple}
  92                 }
  93             }
  94         }
  95     }
  96 }