From owner-freebsd-questions Tue Jul 28 23:23:14 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id XAA20775 for freebsd-questions-outgoing; Tue, 28 Jul 1998 23:23:14 -0700 (PDT) (envelope-from owner-freebsd-questions@FreeBSD.ORG) Received: from smtp.infozoo.com (smtp.INFOZOO.com [12.2.96.18]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id XAA20770 for ; Tue, 28 Jul 1998 23:23:12 -0700 (PDT) (envelope-from Les.LaCroix@Carleton.edu) Received: (qmail 4283 invoked from network); 29 Jul 1998 06:31:53 -0000 Received: from miranda.infozoo.com (12.2.96.16) by smtp.infozoo.com with SMTP; 29 Jul 1998 06:31:53 -0000 Date: Wed, 29 Jul 1998 01:23:30 -0500 From: "Les LaCroix" To: freebsd-questions@FreeBSD.ORG Subject: (long) page fault in kernel mode: suggestions? Message-ID: <4027246050.901675410@miranda.INFOZOO.com> X-Mailer: Mulberry (Win32) [1.3.3, s/n S-397003] MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG I've been fighting a "fatal trap 12: page fault while in kernel mode" problem. Clues are appreciated. I'm running out of ideas. New machine (configuration below). Crashes in a similar (if not the exactly the same) way with GENERIC kernel and a custom kernel with virtually everything removed, in both 2.2.6 and 2.2.7. I've not changed anything in the kernel source. I don't have the panic screen from other days, but tonight it crashed 3 times in 5 hours like this: Fatal trap 12: page fault while in kernel mode fault virtual address = 0xe011087c fault code = supervisor read, page not present instruction pointer = 0x8:0xe011087c stack pointer = 0x10:0xf019cfa0 frame pointer = 0x10:0xf019cfb8 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 = Idle interrupt mask = panic: page fault Each crash was the same: same instruction, stack and frame pointers, same everything. gdb -k on the dumps all look like: (kgdb) symbol-file /kernel Reading symbols from /kernel...done. (kgdb) exec-file /var/crash/kernel.2 (kgdb) core-file /var/crash/vmcore.2 IdlePTD 1c1000 current pcb at 1a8bb0 panic: page fault #0 boot (howto=256) at ../../kern/kern_shutdown.c:266 266 dumppcb.pcb_cr3 = rcr3(); (kgdb) where #0 boot (howto=256) at ../../kern/kern_shutdown.c:266 #1 0xf010eb12 in panic (fmt=0xf017693f "page fault") at ../../kern/kern_shutdown.c:400 #2 0xf017751e in trap_fatal (frame=0xf019cf64) at ./../i386/i386/trap.c:772 #3 0xf0176fe0 in trap_pfault (frame=0xf019cf64, usermode=0) at ../../i386/i386/trap.c:681 #4 0xf0176c77 in trap (frame={tf_es = 16, tf_ds = 16, tf_edi = -1073741824, tf_esi = -535754628, tf_ebp = -266743880, tf_isp = -266743924, tf_ebx = -260199936, tf_edx = -226815792, tf_ecx = 1073741823, tf_eax = -2147483648, tf_trapno = 12, tf_err = 0, tf_eip = -535754628, tf_cs = 8, tf_eflags = 66118, tf_esp = -267363380, tf_ss = -260199936}) at ../../i386/i386/trap.c:324 #5 0xe011087c in ?? () I'm not familiar enough (yet) with gdb and kernel debugging to try to figure out what's going on. My current hunch is that something is corrupting the stack, changing the return address, and causing the page fault when something does a return. The machine: Epox 100Mhz 51MVP3E-M ATX board with 1MB cache: bus clock = 100 MHz multiplier = 3x SDRAM clock = CPU bus clock AMD K6 300 MMX CPU 128MB PC100 SDRAM/ECC 8ns 168-pin DIMM w/ EPROM, 100MHz Mbrds Seagate 6.4GB 7200 RPM IDE drive (ST36530A) Adaptec ISA 1520 SCSI-2 Controller (for an external ZIP, but nothing attached yet) Intel EtherExpress Pro/100B 8MB Millenium II PCI (but not running X or doing anything but dumb console work yet) Teac 24x, IDE (ATAPI) There's nothing interesting running, usually. I killed sendmail and cron (although I left inetd, syslogd, portmap and a couple getty's running). Thanks in advance. ------ Les LaCroix, Carleton College To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message