Date: Fri, 29 Aug 1997 13:51:31 -0400 (EDT) From: Gary Kendall <gdk@ccomp.inode.COM> To: gordon@drogon.NET Cc: hackers@freebsd.ORG Subject: Re: Fatal trap 12: page fault while in kernel mode Message-ID: <199708291751.NAA06741@ccomp.inode.com> In-Reply-To: <Pine.LNX.3.95.970829170904.10277N-100000@unicorn> from Gordon Henderson at "Aug 29, 97 05:11:45 pm"
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It wasn't too long ago that Gordon Henderson said:
>
> I got this last night:
>
> Fatal trap 12: page fault while in kernel mode
> fault virtual address = 0x800010
> fault code = supervisor read, page not present
> instruction pointer = 0x8:0xe0121320
> stack pointer = 0x10:0xdfbfff18
> frame pointer = 0x10:0xdfbfff28
> code segment = base 0x0, limit 0xfffff, type 0x1b
> = DPL 0, pres 1, def32 1, gran 1
> processor eflags = interrupt enabled, resume, IOPL = 0
> current process = 7539 (named-xfer)
> interrupt mask = net tty
> panic: page fault
>
> Can anyone tell me what it means?
>
[snip]
This looks familiar. Were you running pppd at the time, by any chance?
I found a bug in the 2.0 pppd that might have escaped others' attention,
and I just joined this list. ;-) The problem was an splx(s) was missing
before an error return, and left interrupts masked off. What follows is
a patch to a 2.0 /sys/net/if_ppp.c file, so I'd apply it manually (eg,
don't use patch to apply it). Hope this helps.
-------------------------------- cut here ------------------------------------
*** if_ppp.c Wed Jul 9 16:17:41 1997
--- if_ppp.c~ Sat Jul 5 09:58:47 1997
***************
*** 380,389 ****
return (EWOULDBLOCK);
}
error = ttysleep(tp, (caddr_t)&tp->t_rawq, TTIPRI|PCATCH, ttyin, 0);
! if (error) {
! splx(s);
! return (error);
! }
}
if (tp->t_line != PPPDISC) {
splx(s);
--- 380,387 ----
return (EWOULDBLOCK);
}
error = ttysleep(tp, (caddr_t)&tp->t_rawq, TTIPRI|PCATCH, ttyin, 0);
! if (error)
! return error;
}
if (tp->t_line != PPPDISC) {
splx(s);
-------------------------------- cut here ------------------------------------
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