Date: Mon, 3 Jan 2005 12:30:29 GMT From: Robert Watson <rwatson@FreeBSD.org> To: freebsd-bugs@FreeBSD.org Subject: Re: misc/74171: Fatal trap 12: page fault while in kernel mode Message-ID: <200501031230.j03CUTbC021228@freefall.freebsd.org>
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The following reply was made to PR kern/74171; it has been noted by GNATS. From: Robert Watson <rwatson@FreeBSD.org> To: freebsd-gnats-submit@FreeBSD.org Cc: Subject: Re: misc/74171: Fatal trap 12: page fault while in kernel mode Date: Mon, 3 Jan 2005 12:17:35 +0000 (GMT) On Sat, 20 Nov 2004, Normal User wrote: > Fatal trap 12: page fault while in kernel mode > fault virtual address = 0x138 > fault code = supervisor read, page not present > instruction pointer = 0x8:0xc183300d > stack pointer = 0x10:0xcc721c80 > frame pointer = 0x10:0xcc721c90 > code segment = base 0x0, limit 0xfffff, type 0x1b > = DPL0, pres1, def32 1, gran 1 > procesor eflags = resume, IOPL = 0 > current process = 35 (swi5: tty:ltmdm++) > trap number = 12 > panic: page fault > Uptime: 3h9m23s This is a NULL pointer dereference in the kernel or a loaded kernel module. Given that it's in the swi for ltmdm, it's likely a bug in the ltmdm driver, perhaps due to changes in the kernel that the driver has not been updated for. For debugging purposes, it would be useful to have a DDB stack trace in the PR. Could you compile your kernel with "options DDB", reproduce the panic, and use the "trace" command to generate a stack trace? If performed with a serial console, you won't need to do a manual copy-and-paste. Alternatively, you could build a kernel with debugging symbols and use gdb on a core dump, but the DDB trace is usually usefully concise. Thanks! Robert N M Watson > > dmesg reports > > ltmdm0: <Lucent Winmodem> port 0xe800-0xe8ff,0xec00-0xec07 mem 0xdfffff00-0xdfffffff irq 19 at device 8.0 on pci0 > ltmdm0: [GIANT-LOCKED] > ltmdm0: type Virtual 16550A > > > >How-To-Repeat: > just dial my phone number... > >Fix: > > >Release-Note: > >Audit-Trail: > >Unformatted: > _______________________________________________ > freebsd-bugs@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-bugs > To unsubscribe, send any mail to "freebsd-bugs-unsubscribe@freebsd.org" >
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