Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 06 Dec 2024 08:40:01 +0000
From:      bugzilla-noreply@freebsd.org
To:        bugs@FreeBSD.org
Subject:   [Bug 283159] crash dump backtraces broken on arm64
Message-ID:  <bug-283159-227@https.bugs.freebsd.org/bugzilla/>

next in thread | raw e-mail | index | archive | help
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D283159

            Bug ID: 283159
           Summary: crash dump backtraces broken on arm64
           Product: Base System
           Version: 15.0-CURRENT
          Hardware: Any
                OS: Any
            Status: New
          Severity: Affects Only Me
          Priority: ---
         Component: kern
          Assignee: bugs@FreeBSD.org
          Reporter: trasz@FreeBSD.org

For some reason backtraces in crash dumps don't work for me anymore; this is
arm64 Parallels guest:

trasz@v3:~ % uname -a
FreeBSD v3 15.0-CURRENT FreeBSD 15.0-CURRENT #0 main-n274011-0dab21248bc9: =
Wed
Dec  4 19:00:01 UTC 2024=20=20=20=20
root@v3:/usr/obj/usr/home/trasz/git/freebsd/arm64.aarch64/sys/GENERIC arm64
trasz@v3:~ % doas kgdb /boot/kernel/kernel /var/crash/vmcore.last
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.htm=
l>
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: kdb_sysctl_panic
cpuid =3D 1
time =3D 1733474064
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
kdb_sysctl_panic() at kdb_sysctl_panic+0x70
sysctl_root_handler_locked() at sysctl_root_handler_locked+0xe4
sysctl_root() at sysctl_root+0x1e0
userland_sysctl() at userland_sysctl+0x12c
sys___sysctl() at sys___sysctl+0x84
do_el0_sync() at do_el0_sync+0x60c
handle_el0_sync() at handle_el0_sync+0x4c
--- exception, esr 0x56000000
Uptime: 4m24s
Dumping 419 out of 8163 MB:..1%..11%..21%..31%..41%..51%..61%..71%..81%

Reading symbols from /boot/kernel/hwpmc.ko...
Reading symbols from /usr/lib/debug//boot/kernel/hwpmc.ko.debug...
Reading symbols from /boot/kernel/cc_dctcp.ko...
Reading symbols from /usr/lib/debug//boot/kernel/cc_dctcp.ko.debug...
Reading symbols from /boot/kernel/cc_cdg.ko...
Reading symbols from /usr/lib/debug//boot/kernel/cc_cdg.ko.debug...
Reading symbols from /boot/kernel/linux64.ko...
Reading symbols from /usr/lib/debug//boot/kernel/linux64.ko.debug...
Reading symbols from /boot/kernel/mqueuefs.ko...
Reading symbols from /usr/lib/debug//boot/kernel/mqueuefs.ko.debug...
Reading symbols from /boot/kernel/linux_common.ko...
Reading symbols from /usr/lib/debug//boot/kernel/linux_common.ko.debug...
Reading symbols from /boot/kernel/pty.ko...
Reading symbols from /usr/lib/debug//boot/kernel/pty.ko.debug...
Reading symbols from /boot/kernel/fdescfs.ko...
Reading symbols from /usr/lib/debug//boot/kernel/fdescfs.ko.debug...
Reading symbols from /boot/kernel/linprocfs.ko...
Reading symbols from /usr/lib/debug//boot/kernel/linprocfs.ko.debug...
Reading symbols from /boot/kernel/linsysfs.ko...
Reading symbols from /usr/lib/debug//boot/kernel/linsysfs.ko.debug...
Reading symbols from /boot/kernel/virtio_balloon.ko...
Reading symbols from /usr/lib/debug//boot/kernel/virtio_balloon.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/autofs.ko...
Reading symbols from /usr/lib/debug//boot/kernel/autofs.ko.debug...
Reading symbols from /boot/kernel/nullfs.ko...
Reading symbols from /usr/lib/debug//boot/kernel/nullfs.ko.debug...
0xffff0000004b5aa8 in doadump (textdump=3D1) at
/usr/home/trasz/git/freebsd/sys/kern/kern_shutdown.c:404
404             dump_savectx();
(kgdb) bt
#0  0xffff0000004b5aa8 in doadump (textdump=3D1) at
/usr/home/trasz/git/freebsd/sys/kern/kern_shutdown.c:404
#1  0x67fd0000004b5868 in ?? ()
Backtrace stopped: previous frame identical to this frame (corrupt stack?)

I've checked some other threads, and all the backtraces look like this.

(kgdb) info frame
Stack level 0, frame at 0xffff0000c00483c0:
 pc =3D 0xffff0000004b5aa8 in doadump
(/usr/home/trasz/git/freebsd/sys/kern/kern_shutdown.c:404); saved pc =3D
0x67fd0000004b5868
 called by frame at 0xffff0000c00483c0
 source language c.
 Arglist at 0xffff0000c0048390, args: textdump=3D1
 Locals at 0xffff0000c0048390, Previous frame's sp is 0xffff0000c00483c0
 Saved registers:
  x19 at 0xffff0000c00483b8, x20 at 0xffff0000c00483b0, x21 at
0xffff0000c00483a0, x29 at 0xffff0000c0048390, x30 at 0xffff0000c0048398
(kgdb) up
#1  0x67fd0000004b5868 in ?? ()
(kgdb) info frame
Stack level 1, frame at 0xffff0000c00483c0:
 pc =3D 0x67fd0000004b5868; saved pc =3D <not saved>
 Outermost frame: previous frame identical to this frame (corrupt stack?)
 caller of frame at 0xffff0000c00483c0
 Arglist at 0xffff0000c00483d0, args:=20
 Locals at 0xffff0000c00483d0, Previous frame's sp is 0xffff0000c00483c0

Why is saved pc not saved?

--=20
You are receiving this mail because:
You are the assignee for the bug.=



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?bug-283159-227>