Date: Sat, 19 Apr 2003 10:35:44 +0800 From: "David Xu" <davidxu@freebsd.org> To: "John Baldwin" <jhb@freebsd.org>, <src-committers@freebsd.org>, <cvs-src@freebsd.org>, <cvs-all@freebsd.org> Subject: Re: cvs commit: src/sys/alpha/alpha trap.c src/sys/i386/i386 trap.c src/sys/ia64/ia64 trap.c src/sys/kern kern_thread.c src/sys/sparc64/sparc64 trap.c Message-ID: <006c01c3061c$61a7e570$0701a8c0@tiger> References: <200304182020.h3IKK02F035021@repoman.freebsd.org>
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er, I found some code in i386/i386/trap.c:
PROC_LOCK(p);
if ((p->p_flag & P_WEXIT) && (p->p_singlethread != td)) {
mtx_lock_spin(&sched_lock);
thread_exit();
/* NOTREACHED */
}
PROC_UNLOCK(p);
The P_WEXIT and p_singlethread will never be set at same
time. see kern_exit.c. so the code never be executed.
replacing P_WEXIT with P_SINGLE_EXIT will work,
and because 1:1 thread borrows KSE code, so you now need code
like this:
PROC_LOCK(p);
if ((p->p_flag & P_SINGLE_EXIT) && (p->p_singlethread != td)) {
mtx_lock_spin(&sched_lock);
if (p->p_flag & P_THREADED)
thread_exit();
else
thr_exit();
/* NOTREACHED */
}
PROC_UNLOCK(p);
I suggest remove such code from trap.c, just keep it in kernel
thread control code (e.g kern_thread.c or kern_thr.c) to reduce
maintain overhead.
David Xu
----- Original Message -----
From: "John Baldwin" <jhb@FreeBSD.org>
To: <src-committers@FreeBSD.org>; <cvs-src@FreeBSD.org>; <cvs-all@FreeBSD.org>
Sent: Saturday, April 19, 2003 4:20 AM
Subject: cvs commit: src/sys/alpha/alpha trap.c src/sys/i386/i386 trap.c src/sys/ia64/ia64 trap.c src/sys/kern kern_thread.c src/sys/sparc64/sparc64 trap.c
> jhb 2003/04/18 13:20:00 PDT
>
> FreeBSD src repository
>
> Modified files:
> sys/alpha/alpha trap.c
> sys/i386/i386 trap.c
> sys/ia64/ia64 trap.c
> sys/kern kern_thread.c
> sys/sparc64/sparc64 trap.c
> Log:
> Use the proc lock to protect p_singlethread and a P_WEXIT test. This
> fixes a couple of potential KSE panics on non-i386 arch's that weren't
> holding the proc lock when calling thread_exit().
>
> Revision Changes Path
> 1.111 +2 -1 src/sys/alpha/alpha/trap.c
> 1.246 +2 -2 src/sys/i386/i386/trap.c
> 1.73 +3 -1 src/sys/ia64/ia64/trap.c
> 1.117 +2 -2 src/sys/kern/kern_thread.c
> 1.59 +2 -1 src/sys/sparc64/sparc64/trap.c
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