Re: kern/55108: unrelated_tracer_posix_spawn_kill_spawner test kills kernel

[Martin Husemann <martin%duskware.de@localhost>]

The following reply was made to PR kern/55108; it has been noted by GNATS.

From: Martin Husemann <martin%duskware.de@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: kamil%NetBSD.org@localhost
Subject: Re: kern/55108: unrelated_tracer_posix_spawn_kill_spawner test kills
 kernel
Date: Thu, 26 Mar 2020 13:32:17 +0100

 It is:
 
 [ 66143.5985996] panic: tlb_exception: invalid user-space access from kernel mode
 [ 66143.5985996] expevt=40 va=0000006c ssr=40000101 spc=8c1bb366 lwp=0x8e1b1380 onfault=0x0
 [ 66143.5985996] cpu0: Begin traceback...
 [ 66143.5985996] db_panic() at netbsd:vpanic+0xe8
 [ 66143.5985996] vpanic() at netbsd:panic+0x18
 [ 66143.5985996] panic() at netbsd:tlb_exception+0x5a
 [ 66143.5985996] tlb_exception() at 8c0004dc
 [ 66143.5985996] <EXPEVT 040; SSR=40000101> at netbsd:spawn_return+0x426
 [ 66143.5985996] [trapframe 0xfffffffe]
 [ 66143.5985996]    sr=40000101   gbr=74446000    pc=8c1bb366     pr=8c1bb35c
 [ 66143.5985996]    r0=00000000    r1=00000040    r2=000000f0     r3=00000000
 [ 66143.5985996]    r4=8fd59764    r6=00000020    r7=8e1b1380     r8=8c1bb35c
 [ 66143.5985996]    r5=8c00902c    r9=8fa5e360   r10=8e1b1380    r11=8c3fd6c0
 [ 66143.5985996]   r12=00000800   r13=8fa5e2e4   r14=fffffffe sp=r15=c2e58fa4
 [ 66143.5985996] spawn_return() at netbsd:lwp_trampoline+0xc
 
 and that is in:
 
 (gdb) list *(spawn_return+0x426)
 0x8c1bb366 is in spawn_return (../../../../kern/kern_exec.c:2281).
 2276                            mutex_exit(proc_lock);
 2277                            goto cpu_return;
 2278                    }
 2279    
 2280                    mutex_enter(p->p_lock);
 2281                    eventswitch(TRAP_CHLD, PTRACE_POSIX_SPAWN, p->p_opptr->p_pid);
 2282            }
 
 Kamil, could you please have a look?
 
 Thanks!
 
 Martin