Re: panic: softint screwup

[Andrew Doran <ad%netbsd.org@localhost>]

On Tue, Feb 04, 2020 at 07:03:28AM -0400, Jared McNeill wrote:

> First time seeing this one.. an arm64 board sitting idle at the login prompt
> rebooted itself with this panic. Unfortunately the default ddb.onpanic=0
> strikes again and I can't get any more information than this:

I added this recently to replace a vague KASSERT.  Thanks for grabbing the
output.

> [ 364.3342263] curcpu=0, spl=4 curspl=7
> [ 364.3342263] onproc=0xffff00237f743080 => l_stat=7 l_flag=20000201 l_cpu=0
> [ 364.3342263] curlwp=0xffff00237f71e580 => l_stat=1 l_flag=00000200 l_cpu=0
> [ 364.3342263] pinned=0xffff00237f71e100 => l_stat=7 l_flag=00000200 l_cpu=0
> [ 364.3342263] panic: softint screwup
> [ 364.3342263] cpu0: Begin traceback...
> [ 364.3342263] trace fp ffffffc101da7be0
> [ 364.3342263] fp ffffffc101da7c00 vpanic() at ffffffc0004ad728 netbsd:vpanic+0x160
> [ 364.3342263] fp ffffffc101da7c70 panic() at ffffffc0004ad81c netbsd:panic+0x44
> [ 364.3342263] fp ffffffc101da7d40 softint_dispatch() at ffffffc00047bda4 netbsd:softint_dispatch+0x5c4
> [ 364.3342263] fp ffffffc101d9fc30 cpu_switchto_softint() at ffffffc000085198 netbsd:cpu_switchto_softint+0x68
> [ 364.3342263] fp ffffffc101d9fc80 splx() at ffffffc0000040d4 netbsd:splx+0xbc
> [ 364.3342263] fp ffffffc101d9fcb0 callout_softclock() at ffffffc000489e04 netbsd:callout_softclock+0x36c
> [ 364.3342263] fp ffffffc101d9fd40 softint_dispatch() at ffffffc00047b8dc netbsd:softint_dispatch+0xfc
> [ 364.3342263] fp ffffffc101d3fcc0 cpu_switchto_softint() at ffffffc000085198 netbsd:cpu_switchto_softint+0x68
> [ 364.3342263] fp ffffffc101d3fdf8 cpu_idle() at ffffffc000086128 netbsd:cpu_idle+0x58
> [ 364.3342263] fp ffffffc101d3fe40 idle_loop() at ffffffc0004546a4 netbsd:idle_loop+0x174

Something has cleared the LW_RUNNING flag on softclk/0 between where it is
set (unlocked) at line 884 of kern_softint.c and callout_softclock(). 
Should not be possible.  Hmm.

Andrew