http://sourceware.org/ml/gdb-patches/2015-10/msg00301.html Subject: [PATCH 1/3] Never kill PID on: gdb exec PID Hi, in some cases with deleted main executable GDB will want to kill the inferior. $ cp /bin/sleep /tmp/sleep;/tmp/sleep 1h&p=$! $ rm /tmp/sleep $ gdb /tmp/sleep $p GNU gdb (GDB) 7.10.50.20151016-cvs /tmp/sleep: No such file or directory. Attaching to process 9694 /tmp/sleep (deleted): No such file or directory. A program is being debugged already. Kill it? (y or n) _ The first attachment of "/tmp/sleep" commandline argument errors at: #0 throw_error (error=GENERIC_ERROR, fmt=0x116d135 "%s.") at ./common/common-exceptions.c:371 #1 in throw_perror_with_name (errcode=GENERIC_ERROR, string=0x7fffffffdb96 "/dfsfds") at utils.c:974 #2 in perror_with_name (string=0x7fffffffdb96 "/dfsfds") at utils.c:982 #3 in exec_file_attach (filename=0x7fffffffdb96 "/dfsfds", from_tty=1) at exec.c:268 267 if (scratch_chan < 0) 268 perror_with_name (filename); #4 in catch_command_errors_const (command=0x80f59f , arg=0x7fffffffdb96 "/dfsfds", from_tty=1) at main.c:395 #5 in captured_main (data=0x7fffffffd6f0) at main.c:1051 1051 if (catch_command_errors_const (exec_file_attach, execarg, 1052 !batch_flag)) Then GDB tries to attach to the process $p: #0 inferior_appeared (inf=0x240e0b0, pid=29210) at inferior.c:305 #1 in inf_ptrace_attach (ops=0x2339540, args=0x21dcdc0 "29210", from_tty=1) at inf-ptrace.c:206 #2 in linux_nat_attach (ops=0x2339540, args=0x21dcdc0 "29210", from_tty=1) at linux-nat.c:1278 #3 in attach_command (args=0x21dcdc0 "29210", from_tty=1) at infcmd.c:2748 #4 in catch_command_errors (command=0x79d7e5 , arg=0x7fffffffdb9e "29210", from_tty=1) at main.c:368 #5 in captured_main (data=0x7fffffffd6f0) at main.c:1082 1082 if (catch_command_errors (attach_command, pid_or_core_arg, 1083 !batch_flag) == 0) This succeeds and since this moment GDB has a valid inferior. But despite that the lines 1082 if (catch_command_errors (attach_command, pid_or_core_arg, 1083 !batch_flag) == 0) still fail because consequently attach_command() fails to find the associated executable file: #0 throw_error (error=GENERIC_ERROR, fmt=0x116d135 "%s.") at ./common/common-exceptions.c:371 #1 in throw_perror_with_name (errcode=GENERIC_ERROR, string=0x2477860 "/tmp/sleep (deleted)") at utils.c:974 #2 in perror_with_name (string=0x2477860 "/tmp/sleep (deleted)") at utils.c:982 #3 in exec_file_attach (filename=0x2477860 "/tmp/sleep (deleted)", from_tty=1) at exec.c:268 267 if (scratch_chan < 0) 268 perror_with_name (filename); #4 in exec_file_locate_attach (pid=29210, from_tty=1) at exec.c:173 #5 in attach_command_post_wait (args=0x24739b0 "29210", from_tty=1, async_exec=0) at infcmd.c:2628 #6 in attach_command_continuation (args=0x2473590, err=0) at infcmd.c:2700 #7 in do_my_continuations_1 (pmy_chain=0x7fffffffd190, err=0) at continuations.c:59 #8 in do_my_continuations (list=0x240e130, err=0) at continuations.c:83 #9 in do_all_inferior_continuations (err=0) at continuations.c:125 #10 in inferior_event_handler (event_type=INF_EXEC_COMPLETE, client_data=0x0) at inf-loop.c:60 #11 in fetch_inferior_event (client_data=0x0) at infrun.c:3929 #12 in inferior_event_handler (event_type=INF_REG_EVENT, client_data=0x0) at inf-loop.c:44 #13 in handle_target_event (error=0, client_data=0x0) at linux-nat.c:4681 #14 in handle_file_event (file_ptr=0x21e4170, ready_mask=1) at event-loop.c:708 #15 in gdb_wait_for_event (block=0) at event-loop.c:834 #16 in gdb_do_one_event () at event-loop.c:298 #17 in wait_sync_command_done () at top.c:373 #18 in maybe_wait_sync_command_done (was_sync=0) at top.c:388 #19 in catch_command_errors (command=0x79d7e5 , arg=0x7fffffffdb9e "29210", from_tty=1) at main.c:370 #20 in captured_main (data=0x7fffffffd6f0) at main.c:1082 1082 if (catch_command_errors (attach_command, pid_or_core_arg, 1083 !batch_flag) == 0) and therefore GDB executes the following: (gdb) bt #5 in query (ctlstr=0x1141ae8 "A program is being debugged already. Kill it? ") at utils.c:1371 #6 in target_preopen (from_tty=1) at target.c:2183 2179 if (have_inferiors ()) 2180 { 2181 if (!from_tty 2182 || !have_live_inferiors () 2183 || query (_("A program is being debugged already. Kill it? "))) 2184 iterate_over_inferiors (dispose_inferior, NULL); 2185 else 2186 error (_("Program not killed.")); 2187 } #7 in core_open (arg=0x7fffffffdb9f "9694", from_tty=1) at corelow.c:283 #8 in core_file_command (filename=0x7fffffffdb9f "9694", from_tty=1) at corefile.c:77 #9 in catch_command_errors (command=0x86ca16 , arg=0x7fffffffdb9f "9694", from_tty=1) at main.c:368 #10 in captured_main (data=0x7fffffffd6f0) at main.c:1084 1084 catch_command_errors (core_file_command, pid_or_core_arg, 1085 !batch_flag); No regressions on {x86_64,x86_64-m32,i686}-fedora24pre-linux-gnu. Thanks, Jan gdb/ChangeLog 2015-10-16 Jan Kratochvil * main.c (captured_main): Run core_file_command for pid_or_core_arg only if not have_inferiors (). gdb/testsuite/ChangeLog 2015-10-16 Jan Kratochvil * gdb.base/attach-kills.c: New. * gdb.base/attach-kills.exp: New. --- gdb/testsuite/gdb.base/attach-kills.c | 25 ++++++++++++++++ gdb/testsuite/gdb.base/attach-kills.exp | 49 +++++++++++++++++++++++++++++++ 2 files changed, 74 insertions(+) create mode 100644 gdb/testsuite/gdb.base/attach-kills.c create mode 100644 gdb/testsuite/gdb.base/attach-kills.exp diff --git a/gdb/main.c b/gdb/main.c index 49c9b68..bc19699 100644 --- a/gdb/main.c +++ b/gdb/main.c @@ -1080,7 +1080,10 @@ captured_main (void *data) if (isdigit (pid_or_core_arg[0])) { if (catch_command_errors (attach_command, pid_or_core_arg, - !batch_flag) == 0) + !batch_flag) == 0 + /* attach_command could succeed partially and core_file_command + would try to kill it. */ + && !have_inferiors ()) catch_command_errors (core_file_command, pid_or_core_arg, !batch_flag); } diff --git a/gdb/testsuite/gdb.base/attach-kills.c b/gdb/testsuite/gdb.base/attach-kills.c new file mode 100644 index 0000000..2398f00 --- /dev/null +++ b/gdb/testsuite/gdb.base/attach-kills.c @@ -0,0 +1,25 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 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 . */ + +#include + +int +main (void) +{ + sleep (600); + return 0; +} diff --git a/gdb/testsuite/gdb.base/attach-kills.exp b/gdb/testsuite/gdb.base/attach-kills.exp new file mode 100644 index 0000000..9a93cb7 --- /dev/null +++ b/gdb/testsuite/gdb.base/attach-kills.exp @@ -0,0 +1,49 @@ +# Copyright (C) 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 . + +if { ![can_spawn_for_attach] } { + return 0 +} + +standard_testfile + +if { [build_executable ${testfile}.exp $testfile] == -1 } { + return -1 +} + +# Start the program running and then wait for a bit, to be sure +# that it can be attached to. + +set test_spawn_id [spawn_wait_for_attach $binfile] +set testpid [spawn_id_get_pid $test_spawn_id] + +remote_exec target "cp -pf -- $binfile $binfile-copy" +remote_exec target "rm -f -- $binfile" + +set test "start gdb" +set res [gdb_spawn_with_cmdline_opts \ + "-iex \"set height 0\" -iex \"set width 0\" /DoEsNoTeXySt $testpid"] +if { $res != 0} { + fail "$test (spawn)" + kill_wait_spawned_process $test_spawn_id + return -1 +} +gdb_test_multiple "" $test { + -re "\r\nAttaching to .*\r\n$gdb_prompt $" { + pass $test + } +} + +kill_wait_spawned_process $test_spawn_id