Date: Sat, 12 Aug 2017 20:38:05 +0000 From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 213903] Kernel crashes from turnstile_broadcast (/usr/src/sys/kern/subr_turnstile.c:837) Message-ID: <bug-213903-8-mnFN0ZuimK@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-213903-8@https.bugs.freebsd.org/bugzilla/> References: <bug-213903-8@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D213903 Mark Millard <markmi@dsl-only.net> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |markmi@dsl-only.net --- Comment #55 from Mark Millard <markmi@dsl-only.net> --- (In reply to muxx.dev from comment #54)\ Looks to me like ts=3D=3D0x0 was the starting value given to turnstile_broadcast in each backtrace listed in this buzilla bug (213903), for example: (kgdb) list *0xffffffff80b3a89c 0xffffffff80b3a89c is in turnstile_broadcast (/usr/src/sys/kern/subr_turnstile.c:837). 832 833 /* 834 * Transfer the blocked list to the pending list. 835 */ 836 mtx_lock_spin(&td_contested_lock); 837 TAILQ_CONCAT(&ts->ts_pending, &ts->ts_blocked[queue], td_lockq); 838 mtx_unlock_spin(&td_contested_lock); 839 840 /* 841 * Give a turnstile to each thread. The last thread gets Current language: auto; currently minimal (kgdb) backtrace . . . #8 0xffffffff80b3a89c in turnstile_broadcast (ts=3D0x0, queue=3D1) at /usr/src/sys/kern/subr_turnstile.c:837 #9 0xffffffff80ad48cf in __rw_wunlock_hard (c=3D0xfffff800437de858, tid=3D= <value optimized out>, file=3D<value optimized out>, line=3D<value optimized out>)= at /usr/src/sys/kern/kern_rwlock.c:1027 . . . Note that ts=3D=3D0x0 would be a problem for: TAILQ_CONCAT(&ts->ts_pending, &ts->ts_blocked[queue], td_lockq); So I wonder if __rw_wunlock_hard is providing a bad ts value. If yes: the problem then occurs before the turnstile_broadcast call is made. --=20 You are receiving this mail because: You are on the CC list for the bug.=
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