Date: Thu, 05 Jun 2008 00:25:39 +0300 From: Alexander Motin <mav@FreeBSD.org> To: freebsd-stable@freebsd.org Subject: Crashes in devfs. Possibly on interface creation/destruction. Message-ID: <48470853.6080807@FreeBSD.org>
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Hi.
After recent upgrading from 6.3-RC1/mpd-5.0rc1 to 6.3-STABLE/mpd-5.1
some of my PPPoE servers started to crash with about weekly period.
Usually they just just hang without rebooting and core dumping. Consoles
are inaccessible. All I have got from them was:
kernel: Fatal trap 12: page fau
kernel: lt while in k
kernel: ernel
kernel: mode
kernel:
kernel: cpuid = 1; apic id = 01
kernel: faut virtual address = 0x58
kernel:
kernel: fault code = supervisor read, page not present
kernel:
kernel: instruction pointer = 0x20:0xc04800be
kernel:
kernel: stack pointer = 0x28:0xd690883c
kernel: frame pointer = 0x28:0
kernel: xd6908854
kernel: code segment =
kernel: base 0x0, limit 0xfffff, type 0x1b
kernel:
kernel: = DPL 0, pres 1, def32 1, gra
kernel: n 1
kernel: processor eflags = interrupt
kernel: enab
kernel: led, r
kernel: esume
kernel: , IOPL
kernel: = 0
kernel:
kernel: current process = 1835 (mpd5)
kernel:
kernel: trap number = 12
"fault virtual address" and "instruction pointer" are always the same.
Address 0xc04800be looks like part of devfs code:
> addr2line -f -e kernel.debug 0xc04800be
devfs_populate_loop
/usr/src/sys/fs/devfs/devfs_devs.c:443
devfs_devs.c:
de = devfs_newdirent(s, q - s);
if (cdp->cdp_c.si_flags & SI_ALIAS) {
de->de_uid = 0;
de->de_gid = 0;
de->de_mode = 0755;
de->de_dirent->d_type = DT_LNK;
pdev = cdp->cdp_c.si_parent;
->> line 443 ->> j = strlen(pdev->si_name) + 1;
de->de_symlink = malloc(j, M_DEVFS, M_WAITOK);
bcopy(pdev->si_name, de->de_symlink, j);
0x58 - is precisely the offset of si_name field inside of struct cdev.
So looks like pdev = cdp->cdp_c.si_parent is NULL here for some reason.
As soon as network interfaces have respective devfs entries and looking
higher interface creation/destruction rate that newest mpd5.1 is able to
reach due to optimizations, I think it may be some kind or race
somewhere interface creation.
Can somebody give me any hint where to look to?
--
Alexander Motin
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