From owner-freebsd-hackers Tue Oct 20 01:38:50 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id BAA22699 for freebsd-hackers-outgoing; Tue, 20 Oct 1998 01:38:50 -0700 (PDT) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from zephyr.isi.edu (zephyr.isi.edu [128.9.160.160]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id BAA22694 for ; Tue, 20 Oct 1998 01:38:47 -0700 (PDT) (envelope-from surya@ISI.EDU) Received: from localhost (surya@localhost) by zephyr.isi.edu (8.8.7/8.8.6) with SMTP id BAA03240 for ; Tue, 20 Oct 1998 01:38:21 -0700 (PDT) Date: Tue, 20 Oct 1998 01:38:21 -0700 (PDT) From: Stephen Suryaputra To: freebsd-hackers@FreeBSD.ORG Subject: Page fault while in kernel mode, bug? Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Hi, I was running a big simulation as root. I know it is wrong but I want to gain full access to the resources (I tried to setup the limits in /etc/login.conf with no success... however, this part is mine to figure out). When I ran the simulation, I found a seems like interesting bug that you might probably interested in taking a look. Here is a snapshot of the kernel debugger screen: >--- >Fatal trap 12: page fault while in kernel mode >fault virtual address = 0x2b2 >fault code = supervisor read, page not present >instruction pointer = 0x8:0xf01434ba >stack pointer = 0x10:0xefbfff2c >frame pointer = 0x10:0xf2830400 >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 = 2 (page daemon) >interrupt mask = >kernel: type 12 trap, code=0 >Stopped at _vput+0x1a: movl 0x1c(%ebx),%edx > >db>show registers >cs 0x8 >ds 0xefbf0010 >es 0xf03c0010 >ss 0x10 >eax 0x2 >ecx 0x1e >edx 0xefbffe58 _kstack+0x1e58 >ebx 0x296 >esp 0xefbfff2c _kstack+0x1f2c >ebp 0xf2775a80 >esi 0x8 >edi 0x296 >eip 0xf01434ba _vput+0x1a >efl 0x10286 >_vput+0x1a: movl 0x1c(%ebx),%edx This error hit me several times, and for curiosity, I ran exactly the same simulation on two machines and both get the same error, at the same instruction pointer. The interesting part, is that the error shows that there is a page fault in kernel mode. I ran it on FreeBSD-2.2.6-RELEASE and while I ran it, several messages showed up saying that there is not enough swap space. I will be very happy to reproduce the error, and work together with you to find out what's wrong. Thank you. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message