Re: kernel core debugging
- Reply: tuexen_a_freebsd.org: "Re: kernel core debugging"
- In reply to: tuexen_a_freebsd.org: "Re: kernel core debugging"
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Date: Wed, 06 Nov 2024 17:51:07 UTC
On Nov 6, 2024, at 09:28, tuexen@freebsd.org <tuexen@FreeBSD.org> wrote: >> On 6. Nov 2024, at 15:12, Mark Millard <marklmi@yahoo.com> wrote: >> >> On Nov 6, 2024, at 01:44, tuexen@freebsd.org <tuexen@FreeBSD.org> wrote: >> >>> is debugging a kernel panic by using kgdb or lldb on a core file >>> supposed to work? At least it is not right now for me... >> >> # kgdb /boot/kernel.GENERIC-NODEBUG/kernel /var/crash/vmcore.2 >> GNU gdb (GDB) 15.1 [GDB v15.1 for FreeBSD] >> Copyright (C) 2024 Free Software Foundation, Inc. >> License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> >> This is free software: you are free to change and redistribute it. >> There is NO WARRANTY, to the extent permitted by law. >> Type "show copying" and "show warranty" for details. >> This GDB was configured as "aarch64-portbld-freebsd15.0". >> Type "show configuration" for configuration details. >> For bug reporting instructions, please see: >> <https://www.gnu.org/software/gdb/bugs/>. >> Find the GDB manual and other documentation resources online at: >> <http://www.gnu.org/software/gdb/documentation/>. >> >> For help, type "help". >> Type "apropos word" to search for commands related to "word"... >> Reading symbols from /boot/kernel.GENERIC-NODEBUG/kernel... >> Reading symbols from /usr/lib/debug//boot/kernel.GENERIC-NODEBUG/kernel.debug... >> >> Unread portion of the kernel message buffer: >> KDB: enter: manual escape to debugger >> >> Reading symbols from /boot/kernel.GENERIC-NODEBUG/uhid.ko... >> Reading symbols from /usr/lib/debug//boot/kernel.GENERIC-NODEBUG/uhid.ko.debug... >> Reading symbols from /boot/kernel.GENERIC-NODEBUG/wmt.ko... >> Reading symbols from /usr/lib/debug//boot/kernel.GENERIC-NODEBUG/wmt.ko.debug... >> Reading symbols from /boot/kernel.GENERIC-NODEBUG/ums.ko... >> Reading symbols from /usr/lib/debug//boot/kernel.GENERIC-NODEBUG/ums.ko.debug... >> Reading symbols from /boot/kernel.GENERIC-NODEBUG/zfs.ko... >> Reading symbols from /usr/lib/debug//boot/kernel.GENERIC-NODEBUG/zfs.ko.debug... >> 0xffff00000050f3f0 in doadump (textdump=0, textdump@entry=212431136) at /home/pkgbuild/worktrees/main/sys/kern/kern_shutdown.c:404 >> warning: 404 /home/pkgbuild/worktrees/main/sys/kern/kern_shutdown.c: No such file or directory >> (kgdb) bt >> #0 0xffff00000050f3f0 in doadump (textdump=0, textdump@entry=212431136) at /home/pkgbuild/worktrees/main/sys/kern/kern_shutdown.c:404 >> #1 0xffff0000000ee6a8 in db_dump (dummy=<optimized out>, dummy2=<optimized out>, dummy3=<optimized out>, dummy4=<optimized out>) at /home/pkgbuild/worktrees/main/sys/ddb/db_command.c:596 >> #2 0xffff0000000ee478 in db_command (last_cmdp=<optimized out>, cmd_table=<optimized out>, dopager=true) at /home/pkgbuild/worktrees/main/sys/ddb/db_command.c:508 >> #3 0xffff0000000ee150 in db_command_loop () at /home/pkgbuild/worktrees/main/sys/ddb/db_command.c:555 >> #4 0xffff0000000f1ff4 in db_trap (type=<optimized out>, code=<optimized out>) at /home/pkgbuild/worktrees/main/sys/ddb/db_main.c:267 >> #5 0xffff000000568b0c in kdb_trap (type=60, code=0, tf=<optimized out>) at /home/pkgbuild/worktrees/main/sys/kern/subr_kdb.c:790 >> #6 <signal handler called> >> #7 kdb_enter (why=<optimized out>, msg=<optimized out>) at /home/pkgbuild/worktrees/main/sys/kern/subr_kdb.c:556 >> #8 0xffff0000003625cc in vt_machine_kbdevent (vd=<optimized out>, c=<optimized out>) at /home/pkgbuild/worktrees/main/sys/dev/vt/vt_core.c:761 >> #9 vt_processkey (kbd=0xffffa000803caa80, vd=0xffff000000d24360 <vt_consdev>, c=-2147483514) at /home/pkgbuild/worktrees/main/sys/dev/vt/vt_core.c:903 >> #10 vt_kbdevent (kbd=0xffffa000803caa80, event=<optimized out>, arg=0xffff000000d24360 <vt_consdev>) at /home/pkgbuild/worktrees/main/sys/dev/vt/vt_core.c:1030 >> #11 0xffff0000001ea048 in kbdmux_intr (kbd=0xffffa000803caa80, arg=<optimized out>) at /home/pkgbuild/worktrees/main/sys/dev/kbdmux/kbdmux.c:565 >> #12 0xffff0000005839ac in taskqueue_run_locked (queue=queue@entry=0xffffa000803c9c00) at /home/pkgbuild/worktrees/main/sys/kern/subr_taskqueue.c:517 >> #13 0xffff000000583714 in taskqueue_run (queue=0xffffa000803c9c00) at /home/pkgbuild/worktrees/main/sys/kern/subr_taskqueue.c:532 >> #14 0xffff0000004bc114 in intr_event_execute_handlers (ie=0xffffa0008028ec00, p=<optimized out>) at /home/pkgbuild/worktrees/main/sys/kern/kern_intr.c:1183 >> #15 ithread_execute_handlers (ie=0xffffa0008028ec00, p=<optimized out>) at /home/pkgbuild/worktrees/main/sys/kern/kern_intr.c:1196 >> #16 ithread_loop (arg=<optimized out>, arg@entry=0xffffa000803de5a0) at /home/pkgbuild/worktrees/main/sys/kern/kern_intr.c:1289 >> #17 0xffff0000004b700c in fork_exit (callout=0xffff0000004bbd78 <ithread_loop>, arg=0xffffa000803de5a0, frame=0xffff00010ca97a00) at /home/pkgbuild/worktrees/main/sys/kern/kern_fork.c:1151 >> #18 <signal handler called> >> >> The context here was from an official PkgBase kernel and world >> installation. >> >> . . . (deletion) . . . >> >> You may have to be more explicit about the specific of the >> problem(s) you are seeing. > OK. Here is what I am referring to: > > tuexen@head:~ % sudo kgdb -c /var/crash/vmcore.last /boot/kernel/kernel That command does not match the parameter order in the man page or in my example. man kgdb output shows kernel first, then core: SYNOPSIS kgdb [-a | -f | -fullname] [-b rate] [-q | -quiet] [-v] [-w] [-d crashdir] [-c core | -n dumpnr | -r device] [kernel [core]] My example: # kgdb /boot/kernel.GENERIC-NODEBUG/kernel /var/crash/vmcore.2 You might want to see if using the other order makes a difference. > Password: > GNU gdb (GDB) 15.1 [GDB v15.1 for FreeBSD] > Copyright (C) 2024 Free Software Foundation, Inc. > License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> > This is free software: you are free to change and redistribute it. > There is NO WARRANTY, to the extent permitted by law. > Type "show copying" and "show warranty" for details. > This GDB was configured as "aarch64-portbld-freebsd15.0". > Type "show configuration" for configuration details. > For bug reporting instructions, please see: > <https://www.gnu.org/software/gdb/bugs/>. > Find the GDB manual and other documentation resources online at: > <http://www.gnu.org/software/gdb/documentation/>. > > For help, type "help". > Type "apropos word" to search for commands related to "word"... > Reading symbols from /boot/kernel/kernel... > Reading symbols from /usr/lib/debug//boot/kernel/kernel.debug... > > Unread portion of the kernel message buffer: > panic: tcp_do_segment: sent too much > cpuid = 1 > time = 1730910226 > KDB: stack backtrace: > db_trace_self() at db_trace_self > db_trace_self_wrapper() at db_trace_self_wrapper+0x38 > vpanic() at vpanic+0x1a0 > panic() at panic+0x48 > tcp_do_segment() at tcp_do_segment+0x2794 > tcp_input_with_port() at tcp_input_with_port+0xcbc > tcp_input() at tcp_input+0x10 > ip_input() at ip_input+0x35c > netisr_dispatch_src() at netisr_dispatch_src+0xd8 > tunwrite() at tunwrite+0x2a8 > devfs_write_f() at devfs_write_f+0x108 > dofilewrite() at dofilewrite+0x7c > kern_writev() at kern_writev+0x4c > sys_writev() at sys_writev+0x40 > do_el0_sync() at do_el0_sync+0x60c > handle_el0_sync() at handle_el0_sync+0x4c > --- exception, esr 0x56000000 > KDB: enter: panic > > Reading symbols from /boot/kernel/tcp_rack.ko... > Reading symbols from /usr/lib/debug//boot/kernel/tcp_rack.ko.debug... > Reading symbols from /boot/kernel/tcphpts.ko... > Reading symbols from /usr/lib/debug//boot/kernel/tcphpts.ko.debug... > Reading symbols from /boot/kernel/if_bridge.ko... > Reading symbols from /usr/lib/debug//boot/kernel/if_bridge.ko.debug... > Reading symbols from /boot/kernel/bridgestp.ko... > Reading symbols from /usr/lib/debug//boot/kernel/bridgestp.ko.debug... > Reading symbols from /boot/kernel/uhid.ko... > Reading symbols from /usr/lib/debug//boot/kernel/uhid.ko.debug... > Reading symbols from /boot/kernel/wmt.ko... > Reading symbols from /usr/lib/debug//boot/kernel/wmt.ko.debug... > Reading symbols from /boot/kernel/cc_newreno.ko... > Reading symbols from /usr/lib/debug//boot/kernel/cc_newreno.ko.debug... > 0xffff0000004b5644 in doadump (textdump=0) at /usr/home/tuexen/freebsd-src/sys/kern/kern_shutdown.c:404 > 404 dump_savectx(); > (kgdb) up > #1 0x3fdb0000000e99f0 in ?? () > (kgdb) Initial frame selected; you cannot go up. > (kgdb) Initial frame selected; you cannot go up. > (kgdb) quit > tuexen@head:~ % pkg info gdb gdb-15.1 > Name : gdb > Version : 15.1 > Installed on : Thu Oct 24 10:32:17 2024 CEST > Origin : devel/gdb > Architecture : FreeBSD:15:aarch64 > Prefix : /usr/local > Categories : devel > Licenses : GPLv3 > Maintainer : pizzamig@FreeBSD.org > WWW : https://www.gnu.org/software/gdb/ > Comment : GNU Project Debugger > Options : > BUNDLED_READLINE: off > BUNDLED_ZLIB : off > DEBUGINFOD : off > GDB_LINK : on > GUILE : off > KGDB : on > NLS : on > PORT_ICONV : on > PORT_READLINE : on > PYTHON : on > SOURCE_HIGHLIGHT: on > SYSTEM_ICONV : off > SYSTEM_ZLIB : on > TUI : on > XXHASH : on > Shared Libs required: > libzstd.so.1 > libxxhash.so.0 > libsource-highlight.so.4 > libreadline.so.8 > libpython3.11.so.1.0 > libmpfr.so.6 > libintl.so.8 > libiconv.so.2 > libgmp.so.10 > libexpat.so.1 > libboost_regex.so.1.85.0 > Annotations : > FreeBSD_version: 1500025 > build_timestamp: 2024-10-16T20:27:27+0000 > built_by : poudriere-git-3.4.2 > cpe : cpe:2.3:a:gnu:gdb:15.1:::::freebsd15:aarch64 > flavor : py311 > port_checkout_unclean: no > port_git_hash : 82beca9e630 > ports_top_checkout_unclean: no > ports_top_git_hash: 94c4ac6b071 > repo_type : binary > repository : FreeBSD > Flat size : 58.5MiB > Description : > GDB is a source-level debugger for Ada, C, C++, Objective-C, Pascal and > many other languages. GDB can target (i.e., debug programs running on) > more than a dozen different processor architectures, and GDB itself can > run on most popular GNU/Linux, Unix and Microsoft Windows variants. > tuexen@head:~ % > > Using kgdb from "pkg install gdb" and locally built world and kernel. > > Best regards > Michael >> >> For reference: >> >> . . . (deletion) . . . === Mark Millard marklmi at yahoo.com