From 4c2f2a792a5971fcc7fe6511725eaf50d19d302b Mon Sep 17 00:00:00 2001 From: Pedro Alves Date: Mon, 14 Sep 2015 15:45:14 +0100 Subject: Bail out of processing stop if hook-stop resumes target / changes context This patch, relative to a tree with https://sourceware.org/ml/gdb-patches/2015-08/msg00295.html, fixes issues/crashes that trigger if something unexpected happens during a hook-stop. E.g., if the inferior disappears while running the hook-stop, we hit failed assertions: (gdb) define hook-stop Type commands for definition of "hook-stop". End with a line saying just "end". >kill >end (gdb) si Kill the program being debugged? (y or n) [answered Y; input not from terminal] /home/pedro/gdb/mygit/build/../src/gdb/thread.c:88: internal-error: inferior_thread: Assertion `tp' failed. A problem internal to GDB has been detected, further debugging may prove unreliable. Quit this debugging session? (y or n) I noticed that if a hook-stop issues a synchronous execution command, we print the same stop event twice: (gdb) define hook-stop Type commands for definition of "hook-stop". End with a line saying just "end". >si >end (gdb) si 0x000000000040074a 42 args[i] = 1; /* Init value. */ <<<<<<< once 0x000000000040074a 42 args[i] = 1; /* Init value. */ <<<<<<< twice (gdb) In MI: *stopped,reason="end-stepping-range",frame={addr="0x000000000040074a",func="main",args=[],file="threads.c",fullname="/home/pedro/gdb/tests/threads.c",line="42"},thread-id="1",stopped-threads="all",core="0" *stopped,reason="end-stepping-range",frame={addr="0x000000000040074a",func="main",args=[],file="threads.c",fullname="/home/pedro/gdb/tests/threads.c",line="42"},thread-id="1",stopped-threads="all",core="0" (gdb) The fix has GDB stop processing the event if the context changed. I don't expect people to be doing crazy things from the hook-stop. E.g., it gives me headaches to try to come up a proper behavior for handling a thread change from a hook-stop... (E.g., imagine the hook-stop does thread N; step, with scheduler-locing on). I think the most important bit here is preventing crashes. The patch adds a new hook-stop.exp test that covers the above and also merges in the old hook-stop-continue.exp and hook-stop-frame.exp into the same framework. gdb/ChangeLog: 2015-09-14 Pedro Alves * infrun.c (current_stop_id): New global. (get_stop_id, new_stop_id): New functions. (fetch_inferior_event): Handle normal_stop proceeding the target. (struct stop_context): New. (save_stop_context, release_stop_context_cleanup) (stop_context_changed): New functions. (normal_stop): Return true if the hook-stop changes the stop context. * infrun.h (get_stop_id): Declare. (normal_stop): Now returns int. Add documentation. gdb/testsuite/ChangeLog: 2015-09-14 Pedro Alves * gdb.base/hook-stop-continue.c: Delete. * gdb.base/hook-stop-continue.exp: Delete. * gdb.base/hook-stop-frame.c: Delete. * gdb.base/hook-stop-frame.exp: Delete. * gdb.base/hook-stop.c: New file. * gdb.base/hook-stop.exp: New file. --- gdb/testsuite/gdb.base/hook-stop-continue.c | 42 ------- gdb/testsuite/gdb.base/hook-stop-continue.exp | 52 -------- gdb/testsuite/gdb.base/hook-stop-frame.c | 32 ----- gdb/testsuite/gdb.base/hook-stop-frame.exp | 48 -------- gdb/testsuite/gdb.base/hook-stop.c | 38 ++++++ gdb/testsuite/gdb.base/hook-stop.exp | 168 ++++++++++++++++++++++++++ 6 files changed, 206 insertions(+), 174 deletions(-) delete mode 100644 gdb/testsuite/gdb.base/hook-stop-continue.c delete mode 100644 gdb/testsuite/gdb.base/hook-stop-continue.exp delete mode 100644 gdb/testsuite/gdb.base/hook-stop-frame.c delete mode 100644 gdb/testsuite/gdb.base/hook-stop-frame.exp create mode 100644 gdb/testsuite/gdb.base/hook-stop.c create mode 100644 gdb/testsuite/gdb.base/hook-stop.exp (limited to 'gdb/testsuite/gdb.base') diff --git a/gdb/testsuite/gdb.base/hook-stop-continue.c b/gdb/testsuite/gdb.base/hook-stop-continue.c deleted file mode 100644 index 47090fc..0000000 --- a/gdb/testsuite/gdb.base/hook-stop-continue.c +++ /dev/null @@ -1,42 +0,0 @@ -/* This testcase is part of GDB, the GNU debugger. - - Copyright 2008-2015 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 3 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, see . */ - -int -funbreak (int i) -{ - i = i * 2; /* set breakpoint here */ - i = i + 10; - return i; -} - -int -func (int i) -{ - return i * 2; -} - -int -main (int argc, char **argv, char **envp) -{ - func (1); - func (2); - func (3); - func (4); - funbreak (5); - - return 0; -} diff --git a/gdb/testsuite/gdb.base/hook-stop-continue.exp b/gdb/testsuite/gdb.base/hook-stop-continue.exp deleted file mode 100644 index 06c2fe6..0000000 --- a/gdb/testsuite/gdb.base/hook-stop-continue.exp +++ /dev/null @@ -1,52 +0,0 @@ -# Copyright 2008-2015 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 3 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, see . - -standard_testfile .c - -if { [prepare_for_testing ${testfile}.exp "${testfile}" "${testfile}.c" {debug nowarnings}] } { - return -1 -} - -if ![runto_main] then { - perror "Couldn't run to main" -} - -set bp_location [gdb_get_line_number "set breakpoint here"] - -gdb_test "break $bp_location" \ - "Breakpoint.*at.* file .*$srcfile, line $bp_location\\." \ - "breakpoint line number" - -gdb_test "print \$do_continue = 1" "1" - -send_gdb "define hook-stop\n" -gdb_expect { - -re "Type commands for definition of \"hook-stop\".\r\nEnd with a line saying just \"end\".\r\n>$"\ - {send_gdb "if \$do_continue\nset \$do_continue = 0\ncontinue\nend\nend\n" - gdb_expect { - -re "$gdb_prompt $"\ - {pass "define hook-stop command"} - timeout {fail "(timeout) define hook-stop command"} - } - } - -re "$gdb_prompt $"\ - {fail "define hook-stop command"} - timeout {fail "(timeout) define hook-stop command"} -} - -gdb_test "next" "Breakpoint.*funbreak \\(i=5\\) at .*:$bp_location\r\n$bp_location.*set breakpoint here \\*/" \ - "next triggering hook-stop" - -gdb_test "next" "i = i \\+ 10;" "next no hook-stop" diff --git a/gdb/testsuite/gdb.base/hook-stop-frame.c b/gdb/testsuite/gdb.base/hook-stop-frame.c deleted file mode 100644 index 8dbb8f1..0000000 --- a/gdb/testsuite/gdb.base/hook-stop-frame.c +++ /dev/null @@ -1,32 +0,0 @@ -/* This testcase is part of GDB, the GNU debugger. - - Copyright 2009-2015 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 3 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, see . */ - -void -func (void) -{ - int a; - - a = 1; /* set breakpoint here */ -} - -int -main (int argc, char **argv) -{ - func (); - - return 0; -} diff --git a/gdb/testsuite/gdb.base/hook-stop-frame.exp b/gdb/testsuite/gdb.base/hook-stop-frame.exp deleted file mode 100644 index 5b443ff..0000000 --- a/gdb/testsuite/gdb.base/hook-stop-frame.exp +++ /dev/null @@ -1,48 +0,0 @@ -# Copyright 2009-2015 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 3 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, see . - -standard_testfile - -if { [prepare_for_testing ${testfile}.exp "${testfile}" $srcfile {debug nowarnings}] } { - return -1 -} - -if ![runto_main] then { - perror "Couldn't run to main" -} - -set bp_location [gdb_get_line_number "set breakpoint here"] - -gdb_test "break func" \ - "Breakpoint.*at.* file .*$srcfile.*\\." \ - "breakpoint line number" - -set test "define hook-stop command" -gdb_test_multiple "define hook-stop" "$test" { - -re "Type commands for definition of \"hook-stop\".\r\nEnd with a line saying just \"end\".\r\n>$" { - gdb_test "echo \"Hello.\"\nend" "" "$test" - } -} - -set test "hook-stop runs before frame print" -gdb_test_multiple "continue" "$test" { - -re "\"Hello\\.\"\r\nBreakpo.*func.*set breakpoint here.*${gdb_prompt} $" { - pass $test - } - - -re "Breakpo.*func.*set breakpoint here.*\"Hello\\.\".*${gdb_prompt} $" { - fail $test - } -} diff --git a/gdb/testsuite/gdb.base/hook-stop.c b/gdb/testsuite/gdb.base/hook-stop.c new file mode 100644 index 0000000..4152f28 --- /dev/null +++ b/gdb/testsuite/gdb.base/hook-stop.c @@ -0,0 +1,38 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2009-2015 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 3 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, see . */ + +void +func (void) +{ + int a; + + a = 1; /* set breakpoint here */ + a = 2; +} + +int +main (int argc, char **argv) +{ + int i; + + i = 1; + i = 2; + i = 3; + func (); + + return 0; +} diff --git a/gdb/testsuite/gdb.base/hook-stop.exp b/gdb/testsuite/gdb.base/hook-stop.exp new file mode 100644 index 0000000..cdee7db --- /dev/null +++ b/gdb/testsuite/gdb.base/hook-stop.exp @@ -0,0 +1,168 @@ +# Copyright 2009-2015 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 3 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, see . + +standard_testfile + +if { [build_executable ${testfile}.exp "${testfile}" $srcfile {debug nowarnings}] } { + return -1 +} + +# Define the hook-stop that runs COMMANDS. + +proc define_hook_stop {commands} { + set test "define hook-stop command" + gdb_test_multiple "define hook-stop" "$test" { + -re "Type commands for definition of \"hook-stop\".\r\nEnd with a line saying just \"end\".\r\n>$" { + gdb_test "$commands\nend" "" "$test" + } + } +} + +# Restart GDB, run to main, set a breakpoint, and define a hook-stop +# that runs COMMANDS. If running to main fails, this returns to the +# caller's caller directly. + +proc setup {commands} { + global srcfile binfile + + clean_restart $binfile + + if ![runto_main] then { + fail "Can't run to main" + return -code return + } + + gdb_test "break func" \ + "Breakpoint.*at.* file .*$srcfile.*\\." \ + "breakpoint line number" + + define_hook_stop $commands +} + +# Check that the hook-stop runs before the frame is printed. + +proc hook_stop_before_frame {} { + with_test_prefix "hook-stop runs before frame print" { + global gdb_prompt + + setup "echo \"Hello.\"" + + set test "run hook-stop" + gdb_test_multiple "continue" "$test" { + -re "\"Hello\\.\"\r\nBreakpo.*func.*set breakpoint here.*${gdb_prompt} $" { + pass $test + } + + -re "Breakpo.*func.*set breakpoint here.*\"Hello\\.\".*${gdb_prompt} $" { + fail $test + } + } + } +} + +# Check that GDB gracefully handles the case of the inferior dying +# while running the hook-stop. + +proc hook_stop_kill {} { + with_test_prefix "hook-stop kills inferior" { + global gdb_prompt + + setup "kill" + + gdb_test_no_output "set confirm off" + + set test "run hook-stop" + gdb_test_multiple "continue" "$test" { + -re "Continuing.\r\n${gdb_prompt} $" { + pass $test + } + } + + gdb_test "info threads" "No threads.*" + } +} + +# Check that GDB gracefully handles the case of the hook-stop +# continuing the inferior in the foreground. + +proc hook_stop_continue_fg {} { + with_test_prefix "hook-stop runs continue" { + global gdb_prompt + + setup "if \$do_continue\nset \$do_continue = 0\ncontinue\nend" + + gdb_test "print \$do_continue = 1" " = 1" + + gdb_test "next" "Breakpoint.*func \\(\\) at .*set breakpoint here \\*/" \ + "next triggering hook-stop" + + gdb_test "next" "a = 2;" "next no hook-stop" + } +} + +# Check that GDB gracefully handles the case of the hook-stop +# continuing the inferior in the background. + +proc hook_stop_continue_bg {} { + with_test_prefix "hook-stop runs continue&" { + global gdb_prompt + + setup "if \$do_continue\nset \$do_continue = 0\ncontinue&\nend" + + gdb_test "print \$do_continue = 1" " = 1" + + set test "run hook-stop" + gdb_test_multiple "continue" "$test" { + -re "Continuing.\r\n.*${gdb_prompt} " { + pass $test + } + } + + set test "inferior exits normally" + gdb_test_multiple "" "$test" { + -re "exited normally" { + pass $test + } + } + gdb_test "info threads" "No threads.*" + } +} + +# Check that GDB gracefully handles the case of the hook-stop running +# "next". GDB used to print the stop event twice. + +proc hook_stop_next {} { + with_test_prefix "hook-stop runs next" { + global gdb_prompt + + setup "next" + + set test "run hook-stop" + gdb_test_multiple "continue" "$test" { + -re "a = 2.*a = 2${gdb_prompt} $" { + fail $test + } + -re "a = 2.*${gdb_prompt} $" { + pass $test + } + } + } +} + +hook_stop_before_frame +hook_stop_kill +hook_stop_continue_fg +hook_stop_continue_bg +hook_stop_next -- cgit v1.1