Bug 210641 - panic: witness warn during sys/kqueue/kqueue_test:main
Summary: panic: witness warn during sys/kqueue/kqueue_test:main
Status: Closed FIXED
Alias: None
Product: Base System
Classification: Unclassified
Component: kern (show other bugs)
Version: CURRENT
Hardware: Any Any
: --- Affects Some People
Assignee: Eric van Gyzen
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2016-06-27 20:54 UTC by Alan Somers
Modified: 2016-08-12 12:51 UTC (History)
3 users (show)

See Also:

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2016-06-27 20:54 UTC, Alan Somers 		no flags Details
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Description Alan Somers freebsd_committer freebsd_triage 2016-06-27 20:54:28 UTC 
Created attachment 171885 [details]
Textdump

Running sys/kqueue/kqueue_test:main on i386 with FreeBSD 11.0-ALPHA5 r302180M resulted in the following panic:

userret: returning with the following locks held:
exclusive sleep mutex process lock (process lock) r = 0 (0xc827aab0) locked @ /usr/home/alans/freebsd/head/sys/kern/kern_event.c:2125
panic: witness_warn
cpuid = 1
KDB: stack backtrace:
db_trace_self_wrapper(c15b2c1c,c1840520,0,c15850b4,f1174af8,...) at db_trace_self_wrapper+0x2a/frame 0xf1174ac8
kdb_backtrace(c17a4cd1,1,c12208af,f1174b94,1,...) at kdb_backtrace+0x2d/frame 0xf1174b30
vpanic(c12208af,f1174b94,c12208af,f1174b94,f1174b94,...) at vpanic+0x115/frame 0xf1174b64
kassert_panic(c12208af,c15b7038,c827aab0,c15a4df0,84d,...) at kassert_panic+0xd9/frame 0xf1174b88
witness_warn(2,0,c15b570f,f1174ca8,c0bfef10,...) at witness_warn+0x32a/frame 0xf1174bdc
userret(c8abd340,f1174ce8,c15a543f,4,0,...) at userret+0x92/frame 0xf1174c20
syscall(f1174ce8) at syscall+0x50b/frame 0xf1174cdc
Xint0x80_syscall() at Xint0x80_syscall+0x2f/frame 0xf1174cdc
--- syscall (1, FreeBSD ELF32, sys_sys_exit), eip = 0x281a044b, esp = 0xbfbfe8c8, ebp = 0xbfbfe8f0 ---
KDB: enter: panic
Comment 1 Alan Somers freebsd_committer freebsd_triage 2016-06-27 21:00:23 UTC 
The panic is somewhat reproducible.  I hit it two times in nine tries.
Comment 2 Eric van Gyzen freebsd_committer freebsd_triage 2016-06-27 22:30:01 UTC 
This was discussed on -current and is fixed by r302235.

https://lists.freebsd.org/pipermail/freebsd-current/2016-June/061886.html

https://svnweb.freebsd.org/changeset/base/302235