-current amd64 diagnostic panic while loading compat_linux32 module twice

[Nicolas Joly <njoly%pasteur.fr@localhost>]

Hi,

I just encountered a reproductible diagnotic kernel panic while trying
to load the compat_linux32 module twice on my -current amd64
workstation.

root@lanfeust [~]# modstat | grep linux
root@lanfeust [~]# modload compat_linux
root@lanfeust [~]# modload compat_linux32
root@lanfeust [~]# modstat | grep linux
compat_linux    misc    filesys 1       1147014 
compat,compat_ossaudio,exec_elf64
compat_linux32  misc    filesys 0       1059750 
compat_linux,exec_elf32,compat_netbsd32
root@lanfeust [~]# modload compat_linux32
[...PANIC...]

panic: kernel diagnostic assertion "ch->ch_running > 0" failed: file 
"/local/src/NetBSD/src/sys
/kern/subr_callback.c", line 96
fatal breakpoint trap in supervisor mode
trap type 1 code 0 rip ffffffff80237f05 cs 8 rflags 246 cr2  7f7ffd805020 cpl 0 
rsp ffff800049f
bf630
Stopped in pid 549.1 (modload) at       netbsd:breakpoint+0x5:  leave
db{1}> bt
breakpoint() at netbsd:breakpoint+0x5
panic() at netbsd:panic+0x249
__kernassert() at netbsd:__kernassert+0x2d
callback_run_roundrobin() at netbsd:callback_run_roundrobin+0x13d
uvm_map_prepare() at netbsd:uvm_map_prepare+0x178
uvm_map() at netbsd:uvm_map+0xd3
uvm_km_alloc() at netbsd:uvm_km_alloc+0xb1
kobj_load() at netbsd:kobj_load+0xaba
kobj_load_file() at netbsd:kobj_load_file+0x113
module_do_load() at netbsd:module_do_load+0x36c
module_load() at netbsd:module_load+0x73
sys_modctl() at netbsd:sys_modctl+0x2db
syscall() at netbsd:syscall+0xb6

The kernel config is quite simple :

include "arch/amd64/conf/GENERIC"
options         DIAGNOSTIC
no options      COMPAT_LINUX
no options      COMPAT_LINUX32

Any idea ?
Thanks.

-- 
Nicolas Joly

Biological Software and Databanks.
Institut Pasteur, Paris.