Re: Illegal instruction errors under XEN3_DOM0 on -CURRENT

[Dustin Marquess <dmarquess%gmail.com@localhost>]

On Mon, Apr 20, 2020 at 3:03 AM Manuel Bouyer <bouyer%antioche.eu.org@localhost> wrote:
>
> On Sun, Apr 19, 2020 at 08:23:30PM -0500, Dustin Marquess wrote:
> > I've been playing with a PC Engines apu4d4 box.  Installed -CURRENT
> > from the nycdn builds, and everything works great.
> >
> > I installed the xenkernel411 and xentools411 packages, copied xen.gz
> > to /, and added to boot.cfg:
> >
> > menu=Xen:load /netbsd-XEN3_DOM0.gz console=pc;multiboot /xen.gz
> > dom0_mem=512M console=com1 com1=115200,8n1 dom0_max_vcpus=1
> >
> > The Xen kernel boots fine and then the NetBSD dom0 starts.  However,
> > just about everything illegal instruction dumps:
[SNIP]
> > However booting the GENERIC kernel again works just fine.  This is
> > from the same build, although I've tried DOM0 kernels from the last
> > few days from nycdn.
> >
> > Any idea?
>
> It could help to know what intruction is causing it.
> If you have core dumps, you should be able to see it with gdb.

Indeed.  Sorry about that.

Put in a large SD card so I could store the core files.  Strangely I
don't seen anything common really standing out.

awk:

(gdb) where
#0  0x0000000142a13d14 in syminit ()
#1  0x0000000000000000 in ?? ()
(gdb) disas syminit
Dump of assembler code for function syminit:
   0x0000000142a13d00 <+0>:       push   %rbp
   0x0000000142a13d01 <+1>:       push   %rbx
   0x0000000142a13d02 <+2>:       sub    $0x8,%rsp
   0x0000000142a13d06 <+6>:       lea    0x21f613(%rip),%rbx        #
0x142c33320 <symtab>
   0x0000000142a13d0d <+13>:      lea    0x180b9(%rip),%rsi        # 0x142a2bdcd
=> 0x0000000142a13d14 <+20>:      vxorpd %xmm0,%xmm0,%xmm0
   0x0000000142a13d18 <+24>:      mov    %rsi,%rdi


dev_mkdb:

(gdb) bt
#0  0x0000766612b7df69 in ?? () from /usr/lib/libc.so.12
#1  0x0000766612b7e4f1 in arc4random_uniform () from /usr/lib/libc.so.12
#2  0x0000766612b7d706 in __gettemp () from /usr/lib/libc.so.12
#3  0x0000766612a95a12 in mktemp () from /usr/lib/libc.so.12
#4  0x000000003fa0177b in main ()


makemandb:

(gdb) bt
#0  0x00007a02c0e91922 in ?? () from /usr/lib/libsqlite3.so.1
#1  0x00007a02c0e97298 in ?? () from /usr/lib/libsqlite3.so.1
#2  0x00007a02c0e990bd in ?? () from /usr/lib/libsqlite3.so.1
#3  0x00007a02c0e993ea in ?? () from /usr/lib/libsqlite3.so.1
#4  0x00007a02c0e92056 in ?? () from /usr/lib/libsqlite3.so.1
#5  0x00007a02c0e962b2 in ?? () from /usr/lib/libsqlite3.so.1
#6  0x00007a02c0e96806 in ?? () from /usr/lib/libsqlite3.so.1
#7  0x00007a02c0e96af6 in sqlite3_prepare_v2 () from /usr/lib/libsqlite3.so.1
#8  0x00007a02c0e8145b in sqlite3_exec () from /usr/lib/libsqlite3.so.1
#9  0x00000000b2c48fcb in main ()


mount_tmpfs:

(gdb) bt
#0  0x0000775e1fd6fd75 in __strtodg_D2A () from /lib/libc.so.12
#1  0x0000775e1fcbc6bd in ?? () from /lib/libc.so.12
#2  0x00000000f04017b7 in mount_tmpfs_parseargs ()
#3  0x00000000f0401aab in mount_tmpfs ()
#4  0x00000000f040147c in ___start ()
#5  0x00007f7e20e0d280 in ?? () from /libexec/ld.elf_so
#6  0x0000000000000005 in ?? ()
#7  0x00007f7fff7c5ac8 in ?? ()
#8  0x00007f7fff7c5ad4 in ?? ()
#9  0x00007f7fff7c5adb in ?? ()
#10 0x00007f7fff7c5ae4 in ?? ()
#11 0x00007f7fff7c5aea in ?? ()
#12 0x0000000000000000 in ?? ()
disasm:
   0x0000775e1fd6fd67 <+1151>:    cmp    $0x10,%r14d
   0x0000775e1fd6fd6b <+1155>:    cmovle %r14d,%r13d
   0x0000775e1fd6fd6f <+1159>:    mov    %ebp,%eax
   0x0000775e1fd6fd71 <+1161>:    cmp    $0x9,%r14d
=> 0x0000775e1fd6fd75 <+1165>:    vcvtsi2sd %rax,%xmm0,%xmm0
   0x0000775e1fd6fd7a <+1170>:    vmovdqa %xmm0,%xmm1


ntpd:

(gdb) bt
#0  0x000000019d07b0ee in get_systime ()
#1  0x000000019d04ad59 in ntpdmain ()
#2  0x000000019d09d1c9 in main ()
diasm:
   0x000000019d07b0d1 <+185>:     jne    0x19d07b0e7 <get_systime+207>
   0x000000019d07b0d3 <+187>:     lea    0x2b8f1e(%rip),%rax        #
0x19d333ff8 <sys_lamport>
   0x000000019d07b0da <+194>:     movl   $0x1,0x2b6120(%rip)        #
0x19d331204
   0x000000019d07b0e4 <+204>:     incq   (%rax)
   0x000000019d07b0e7 <+207>:     lea    0x2b8f02(%rip),%r12        #
0x19d333ff0 <using_sigio>
=> 0x000000019d07b0ee <+214>:     vmovdqa (%rsp),%xmm0
   0x000000019d07b0f3 <+219>:     mov    (%r12),%r9d


sshd:

(gdb) bt
#0  0x000078d72d17df69 in ?? () from /usr/lib/libc.so.12
#1  0x000078d72d17e1e5 in arc4random_buf () from /usr/lib/libc.so.12
#2  0x000078d72dc3473f in sshkey_shield_private () from /usr/lib/libssh.so.36
#3  0x00000001cf8383ea in main ()


-Dustin