sleep 1h& pid=$!; kill -STOP $pid; gdb sleep $pid -> Attaching to program: /bin/sleep, process 20768 ../../gdb/linux-nat.c:1057: internal-error: linux_nat_attach: Assertion `pid == GET_PID (inferior_ptid) && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP' failed. Specific to Red Hat kernels, kernel.org kernels lockup on gdb "attach". 2006-09-17 Jan Kratochvil * gdb-6.5/gdb/linux-nat.c (linux_nat_attach): Handle already stopped processes. 2006-09-17 Jeff Johnston Jan Kratochvil * gdb.base/attachstop.exp, gdb.base/attachstop.c: New files, test attaching to already stopped processes. Index: gdb-6.5/gdb/linux-nat.c =================================================================== RCS file: /cvs/src/src/gdb/linux-nat.c,v retrieving revision 1.50 diff -u -p -r1.50 linux-nat.c --- gdb-6.5-orig/gdb/linux-nat.c 16 Sep 2006 09:48:12 -0000 1.50 +++ gdb-6.5/gdb/linux-nat.c 17 Sep 2006 21:50:32 -0000 @@ -1022,13 +1022,16 @@ linux_nat_attach (char *args, int from_t lp->cloned = 1; } - gdb_assert (pid == GET_PID (inferior_ptid) - && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP); + /* Do not check `WSTOPSIG (status) == SIGSTOP' as the status may be + arbitrary - depending on the signal that stopped the processes. + If the process was running we get SIGSTOP, if it was already stopped + by SIGSTOP we get 0. The value gets used for `PTRACE_CONT'. */ + gdb_assert (pid == GET_PID (inferior_ptid) && WIFSTOPPED (status)); lp->stopped = 1; - /* Fake the SIGSTOP that core GDB expects. */ - lp->status = W_STOPCODE (SIGSTOP); + /* Provide the stop status that core GDB expects. */ + lp->status = status; lp->resumed = 1; if (debug_linux_nat) { Index: gdb-6.5/gdb/testsuite/gdb.base/attachstop.c =================================================================== RCS file: gdb-6.5/gdb/testsuite/gdb.base/attachstop.c diff -N gdb-6.5/gdb/testsuite/gdb.base/attachstop.c --- /dev/null 1 Jan 1970 00:00:00 -0000 +++ gdb-6.5/gdb/testsuite/gdb.base/attachstop.c 17 Sep 2006 21:50:32 -0000 @@ -0,0 +1,29 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2005 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 2 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, write to the Free Software + Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + +/* This program is intended to be started outside of gdb, then + manually stopped via a signal. */ + +#include + +int main () +{ + sleep (10000); /* Ridiculous time, but we will eventually kill it. */ + sleep (10000); /* Second sleep. */ + return 0; +} Index: gdb-6.5/gdb/testsuite/gdb.base/attachstop.exp =================================================================== RCS file: gdb-6.5/gdb/testsuite/gdb.base/attachstop.exp diff -N gdb-6.5/gdb/testsuite/gdb.base/attachstop.exp --- /dev/null 1 Jan 1970 00:00:00 -0000 +++ gdb-6.5/gdb/testsuite/gdb.base/attachstop.exp 17 Sep 2006 21:50:32 -0000 @@ -0,0 +1,198 @@ +# Copyright 2005-2006 + +# 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 2 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, write to the Free Software +# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + +# This test was created by modifying attach.exp. +# This file was created by Jeff Johnston . +# This file was updated by Jan Kratochvil . + +if $tracelevel then { + strace $tracelevel +} + +set prms_id 0 +set bug_id 0 + +# This test only works on Linux +if { ![istarget "*-*-linux-gnu*"] } { + return 0 +} + +set testfile "attachstop" +set srcfile ${testfile}.c +set binfile ${objdir}/${subdir}/${testfile} +set escapedbinfile [string_to_regexp ${objdir}/${subdir}/${testfile}] + +#execute_anywhere "rm -f ${binfile}" +remote_exec build "rm -f ${binfile}" +# For debugging this test +# +#log_user 1 + +# build the test case +# +if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug}] != "" } { + gdb_suppress_entire_file "Testcase compile failed, so all tests in this file will automatically fail." +} + +if [get_compiler_info ${binfile}] { + return -1 +} + +# Start the program running and then wait for a bit, to be sure +# that it can be attached to. + +set testpid [eval exec $binfile &] +exec sleep 2 + +# Stop the program +remote_exec build "kill -s STOP ${testpid}" + +# Start with clean gdb +gdb_exit +gdb_start +gdb_reinitialize_dir $srcdir/$subdir +gdb_load ${binfile} + +# Verify that we can attach to the process by first giving its +# executable name via the file command, and using attach with the +# process ID. + +set test "set file, before attach1 to stopped process" +gdb_test_multiple "file $binfile" "$test" { + -re "Load new symbol table from.*y or n. $" { + gdb_test "y" "Reading symbols from $escapedbinfile\.\.\.*done." \ + "$test (re-read)" + } + -re "Reading symbols from $escapedbinfile\.\.\.*done.*$gdb_prompt $" { + pass "$test" + } +} + +set test "attach1 to stopped, after setting file" +gdb_test_multiple "attach $testpid" "$test" { + -re "Attaching to program.*`?$escapedbinfile'?, process $testpid.*$gdb_prompt $" { + pass "$test" + } +} + +gdb_test "bt" ".*sleep.*main.*" "attach1 to stopped bt" + +# Exit and detach the process. + +gdb_exit + +set fileid [open /proc/${testpid}/status r]; +gets $fileid line1; +gets $fileid line2; +close $fileid; + +set test "attach1, exit leaves process stopped" +if {[string match "*(stopped)*" $line2]} { + pass $test +} else { + fail $test +} + +# At this point, the process should still be stopped + +gdb_start +gdb_reinitialize_dir $srcdir/$subdir +gdb_load ${binfile} + +# Verify that we can attach to the process just by giving the +# process ID. + +set test "attach2 to stopped, after setting file" +gdb_test_multiple "attach $testpid" "$test" { + -re "Attaching to program.*`?$escapedbinfile'?, process $testpid.*$gdb_prompt $" { + pass "$test" + } +} + +gdb_test "bt" ".*sleep.*main.*" "attach2 to stopped bt" +gdb_breakpoint [gdb_get_line_number "Second sleep"] +set test "attach2 continue" +send_gdb "continue\n" +gdb_expect { + -re "Continuing" + { pass "continue ($test)" } + timeout + { fail "continue ($test) (timeout)" } +} + +# For this to work we must be sure to consume the "Continuing." +# message first, or GDB's signal handler may not be in place. +after 1000 {send_gdb "\003"} +set test "attach2 stop unbreakable interrupt" +gdb_expect 4 { + -re "Program received signal SIGINT.*$gdb_prompt $" + { + fail "$test (broke into)" + } + -re "Breakpoint \[0-9\].*$srcfile.*$gdb_prompt $" + { + fail "$test (broke into)" + } + timeout + { + pass $test + } +} + +# Continue the program +remote_exec build "kill -s CONT ${testpid}" + +# Already sent before: after 1000 {send_gdb "\003"} +set test "attach2 stop by interrupt" +gdb_expect { + -re "Program received signal SIGINT.*$gdb_prompt $" + { + pass $test + } + -re "Breakpoint \[0-9\].*$srcfile.*$gdb_prompt $" + { + pass $test + } + timeout + { + fail "$test (timeout)" + } +} + +gdb_exit + +# At this point, the process should be sleeping + +set fileid2 [open /proc/${testpid}/status r]; +gets $fileid2 line1; +gets $fileid2 line2; +close $fileid2; + +set test "attach2, exit leaves process sleeping" +if {[string match "*(sleeping)*" $line2]} { + pass $test +} else { + fail $test +} + +# Make sure we don't leave a process around to confuse +# the next test run (and prevent the compile by keeping +# the text file busy), in case the "set should_exit" didn't +# work. + +remote_exec build "kill -9 ${testpid}" + +return 0