From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 21265 invoked by alias); 30 Sep 2007 04:02:13 -0000 Received: (qmail 21249 invoked by uid 22791); 30 Sep 2007 04:02:11 -0000 X-Spam-Check-By: sourceware.org Received: from wa-out-1112.google.com (HELO wa-out-1112.google.com) (209.85.146.181) by sourceware.org (qpsmtpd/0.31) with ESMTP; Sun, 30 Sep 2007 04:02:08 +0000 Received: by wa-out-1112.google.com with SMTP id l35so4367095waf for ; Sat, 29 Sep 2007 21:02:06 -0700 (PDT) Received: by 10.115.76.1 with SMTP id d1mr2146272wal.1191124926251; Sat, 29 Sep 2007 21:02:06 -0700 (PDT) Received: by 10.114.13.15 with HTTP; Sat, 29 Sep 2007 21:02:06 -0700 (PDT) Message-ID: Date: Sun, 30 Sep 2007 06:20:00 -0000 From: "Kip Macy" To: "Eric Schuele" Subject: Re: Trouble with gdb 6.6 and one particular app on FreeBSD 7.0... Cc: gdb@sourceware.org In-Reply-To: <46FF1E8B.1040402@computer.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <46FF1E8B.1040402@computer.org> Mailing-List: contact gdb-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sourceware.org X-SW-Source: 2007-09/txt/msg00277.txt.bz2 On 9/29/07, Eric Schuele wrote: > Hello, > > I have a particular app that I am unable to debug using gdb. When I > attach to the app and continue it, gdb begins to take up 100% of my cpu. > It will do this forever (well longer than I've ever waited). > > I am able to debug this particular app on my 6.2-STABLE machine. And I > can debug other apps on my 7.0 machine. I've tried both gdb 6.1 and gdb > 6.6 on my 7.0 machine with no change in behavior. > > I first thought maybe I had done something odd when rebuilding my > kernel/world? But I've built a second 7.0 machine and stuck with the > GENERIC kernel and I have the same results. > > Most times I can not break into the app once I have continued it. I > have attached gdb to gdb to watch what it is doing and it appears to > give me a few different backtraces, though it is always one of maybe > three traces. [See below for bt of gdb attached to gdb, unfortunately > its not the same bt I was seeing... but may offer some insight?] > > Has anyone seen behavior like this? What else can I provide that might > help diagnose this? This sounds more like a ptrace bug / change in behavior. My first guess is that the behavior of ptrace has changed and that gdb is expecting a different return code from the one that it is getting. Is your app threaded? The default threading library has changed. Can you produce a small test case that causes this behavior? Thanks. -Kip > > -- > Regards, > Eric > > Several backtraces of gdb ==> gdb in same session... > > Program received signal SIGINT, Interrupt. > 0x0805241b in find_pc_sect_section (pc=681465567, section=0x0) > at objfiles.c:762 > 762 in objfiles.c > (gdb) bt > #0 0x0805241b in find_pc_sect_section (pc=681465567, section=0x0) > at objfiles.c:762 > #1 0x0805249a in find_pc_section (pc=681465567) at objfiles.c:776 > #2 0x080aa087 in find_pc_partial_function (pc=681465567, name=0xbfbfe590, > address=0xbfbfe588, endaddr=0xbfbfe58c) at blockframe.c:189 > #3 0x080eed68 in handle_inferior_event (ecs=0xbfbfe574) at infrun.c:1776 > #4 0x080ed63e in wait_for_inferior () at infrun.c:1009 > #5 0x080ed46a in proceed (addr=4294967295, siggnal=TARGET_SIGNAL_DEFAULT, > step=0) at infrun.c:827 > #6 0x080ea249 in continue_command (proc_count_exp=0x0, from_tty=1) > at infcmd.c:642 > #7 0x0808082b in do_cfunc (c=0x28977190, args=0x0, from_tty=1) > at .././gdb/cli/cli-decode.c:62 > #8 0x08082e6d in cmd_func (cmd=0x28977190, args=0x0, from_tty=1) > at .././gdb/cli/cli-decode.c:1666 > #9 0x08054cbd in execute_command (p=0x2890c081 "", from_tty=1) at top.c:455 > #10 0x080feadf in command_handler (command=0x2890c080 "c") at > event-top.c:519 > #11 0x080ff307 in command_line_handler (rl=0x2895b112 "c") at > event-top.c:804 > #12 0x28319826 in rl_callback_read_char () from /lib/libreadline.so.7 > #13 0x080fe1cf in rl_callback_read_char_wrapper (client_data=0x0) > at event-top.c:179 > #14 0x080fe96f in stdin_event_handler (error=0, client_data=0x0) > at event-top.c:432 > ---Type to continue, or q to quit--- > #15 0x080fd860 in handle_file_event (event_file_desc=0) at event-loop.c:730 > #16 0x080fd090 in process_event () at event-loop.c:343 > #17 0x080fd0d9 in gdb_do_one_event (data=0x0) at event-loop.c:380 > #18 0x080fa46c in catch_errors (func=0x80fd0a5 , > func_args=0x0, errstring=0x8262c9e "", mask=6) at exceptions.c:515 > #19 0x0809b11b in tui_command_loop (data=0x0) at > .././gdb/tui/tui-interp.c:151 > #20 0x080fa95d in current_interp_command_loop () at interps.c:278 > #21 0x0804eec7 in captured_command_loop (data=0x0) at .././gdb/main.c:101 > #22 0x080fa46c in catch_errors (func=0x804eebc , > func_args=0x0, errstring=0x824f0e6 "", mask=6) at exceptions.c:515 > #23 0x0804fd3c in captured_main (data=0xbfbfead4) at .././gdb/main.c:826 > #24 0x080fa46c in catch_errors (func=0x804eefd , > func_args=0xbfbfead4, errstring=0x824f0e6 "", mask=6) at > exceptions.c:515 > #25 0x0804fdad in gdb_main (args=0xbfbfead4) at .././gdb/main.c:835 > #26 0x0804eeb1 in main (argc=3, argv=0xbfbfeb28) at gdb.c:44 > (gdb) c > Continuing. > ^C > Program received signal SIGINT, Interrupt. > 0x080b80e1 in set_register_cached (regnum=15, state=0) at regcache.c:434 > 434 regcache.c: No such file or directory. > in regcache.c > (gdb) bt > #0 0x080b80e1 in set_register_cached (regnum=15, state=0) at regcache.c:434 > #1 0x080b8186 in registers_changed () at regcache.c:472 > #2 0x080f063c in prepare_to_wait (ecs=0xbfbfe574) at infrun.c:2917 > #3 0x080f05f8 in keep_going (ecs=0xbfbfe574) at infrun.c:2895 > #4 0x080ef284 in handle_inferior_event (ecs=0xbfbfe574) at infrun.c:2021 > #5 0x080ed63e in wait_for_inferior () at infrun.c:1009 > #6 0x080ed46a in proceed (addr=4294967295, siggnal=TARGET_SIGNAL_DEFAULT, > step=0) at infrun.c:827 > #7 0x080ea249 in continue_command (proc_count_exp=0x0, from_tty=1) > at infcmd.c:642 > #8 0x0808082b in do_cfunc (c=0x28977190, args=0x0, from_tty=1) > at .././gdb/cli/cli-decode.c:62 > #9 0x08082e6d in cmd_func (cmd=0x28977190, args=0x0, from_tty=1) > at .././gdb/cli/cli-decode.c:1666 > #10 0x08054cbd in execute_command (p=0x2890c081 "", from_tty=1) at top.c:455 > #11 0x080feadf in command_handler (command=0x2890c080 "c") at > event-top.c:519 > #12 0x080ff307 in command_line_handler (rl=0x2895b112 "c") at > event-top.c:804 > #13 0x28319826 in rl_callback_read_char () from /lib/libreadline.so.7 > #14 0x080fe1cf in rl_callback_read_char_wrapper (client_data=0x0) > at event-top.c:179 > #15 0x080fe96f in stdin_event_handler (error=0, client_data=0x0) > at event-top.c:432 > #16 0x080fd860 in handle_file_event (event_file_desc=0) at event-loop.c:730 > ---Type to continue, or q to quit---q > Quit > (gdb) c > Continuing. > ^C > Program received signal SIGINT, Interrupt. > 0x28784c0b in ?? () from /lib/libc.so.7 > (gdb) bt > #0 0x28784c0b in ?? () from /lib/libc.so.7 > #1 0xbfbfe2b0 in ?? () > #2 0x28980c20 in ?? () > #3 0x00000004 in ?? () > #4 0x00003f80 in ?? () > #5 0x00000000 in ?? () > (gdb) c > Continuing. > ^C > Program received signal SIGINT, Interrupt. > 0x2874cbbb in ptrace () from /lib/libc.so.7 > (gdb) bt > #0 0x2874cbbb in ptrace () from /lib/libc.so.7 > #1 0x08068b42 in i386fbsd_resume (ptid={pid = -1, lwp = 0, tid = 0}, > step=0, > signal=TARGET_SIGNAL_CHLD) at i386fbsd-nat.c:76 > #2 0x080ed0de in resume (step=0, sig=TARGET_SIGNAL_CHLD) at infrun.c:626 > #3 0x080f05ed in keep_going (ecs=0xbfbfe574) at infrun.c:2892 > #4 0x080ef284 in handle_inferior_event (ecs=0xbfbfe574) at infrun.c:2021 > #5 0x080ed63e in wait_for_inferior () at infrun.c:1009 > #6 0x080ed46a in proceed (addr=4294967295, siggnal=TARGET_SIGNAL_DEFAULT, > step=0) at infrun.c:827 > #7 0x080ea249 in continue_command (proc_count_exp=0x0, from_tty=1) > at infcmd.c:642 > #8 0x0808082b in do_cfunc (c=0x28977190, args=0x0, from_tty=1) > at .././gdb/cli/cli-decode.c:62 > #9 0x08082e6d in cmd_func (cmd=0x28977190, args=0x0, from_tty=1) > at .././gdb/cli/cli-decode.c:1666 > #10 0x08054cbd in execute_command (p=0x2890c081 "", from_tty=1) at top.c:455 > #11 0x080feadf in command_handler (command=0x2890c080 "c") at > event-top.c:519 > #12 0x080ff307 in command_line_handler (rl=0x2895b112 "c") at > event-top.c:804 > #13 0x28319826 in rl_callback_read_char () from /lib/libreadline.so.7 > #14 0x080fe1cf in rl_callback_read_char_wrapper (client_data=0x0) > at event-top.c:179 > #15 0x080fe96f in stdin_event_handler (error=0, client_data=0x0) > at event-top.c:432 > ---Type to continue, or q to quit--- > > > >