kern/133902: [tun] Killing tun0 iface ssh tunnel causes Panic String: page fault

[Mikolaj Golub]

The following reply was made to PR kern/133902; it has been noted by GNATS.

From: Mikolaj Golub <to.my.trociny at gmail.com>
To: bug-followup at FreeBSD.org
Cc: freebsd-bugs at FreeBSD.org,  freebsd-net at FreeBSD.org, lsantagostini at gmail.com
Subject: Re: kern/133902: [tun] Killing tun0 iface ssh tunnel causes Panic String: page fault
Date: Thu, 23 Apr 2009 17:14:02 +0300

 I have asked Leonardo to provide more info and backtrace.
 
 So here is backtrace:
 
 cobra4# kgdb /boot/kernel/kernel.symbols /var/crash/vmcore.0
 [GDB will not be able to debug user-mode threads:
 /usr/lib/libthread_db.so: Undefined symbol "ps_pglobal_lookup"]
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 This GDB was configured as "i386-marcel-freebsd".
 
 Unread portion of the kernel message buffer:
 
 
 Fatal trap 12: page fault while in kernel mode
 cpuid = 0; apic id = 00
 fault virtual address   = 0x65656c7b
 fault code              = supervisor write, page not present
 instruction pointer     = 0x20:0xc0786e00
 stack pointer           = 0x28:0xe958fac4
 frame pointer           = 0x28:0xe958fac4
 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         = 66873 (ssh)
 trap number             = 12
 panic: page fault
 cpuid = 1
 Uptime: 54d11h21m54s
 Physical memory: 2023 MB
 Dumping 277 MB: 262 246 230 214 198 182 166 150 134 118 102 86 70 54 38 22 6
 
 #0  doadump () at pcpu.h:195
 195     pcpu.h: No such file or directory.
         in pcpu.h
 (kgdb) backtrace
 #0  doadump () at pcpu.h:195
 #1  0xc0754457 in boot (howto=260) at /usr/src/sys/kern/kern_shutdown.c:409
 #2  0xc0754719 in panic (fmt=Variable "fmt" is not available.
 ) at /usr/src/sys/kern/kern_shutdown.c:563
 #3  0xc0a4905c in trap_fatal (frame=0xe958fa84, eva=1701145723) at
 /usr/src/sys/i386/i386/trap.c:899
 #4  0xc0a492e0 in trap_pfault (frame=0xe958fa84, usermode=0,
 eva=1701145723) at /usr/src/sys/i386/i386/trap.c:812
 #5  0xc0a49c8c in trap (frame=0xe958fa84) at /usr/src/sys/i386/i386/trap.c:490
 #6  0xc0a2fc0b in calltrap () at /usr/src/sys/i386/i386/exception.s:139
 #7  0xc0786e00 in clear_selinfo_list (td=0xca3fc840) at
 /usr/src/sys/kern/sys_generic.c:1065
 #8  0xc0788efc in kern_select (td=0xca3fc840, nd=8, fd_in=0x284010b8,
 fd_ou=0x284010bc, fd_ex=0x0, tvp=0x0) at
 /usr/src/sys/kern/sys_generic.c:794
 #9  0xc07890de in select (td=0xca3fc840, uap=0xe958fcfc) at
 /usr/src/sys/kern/sys_generic.c:663
 #10 0xc0a49635 in syscall (frame=0xe958fd38) at
 /usr/src/sys/i386/i386/trap.c:1035
 #11 0xc0a2fc70 in Xint0x80_syscall () at /usr/src/sys/i386/i386/exception.s:196
 #12 0x00000033 in ?? ()
 Previous frame inner to this frame (corrupt stack?)
 (kgdb)
 
 The system panics on
 
 ifconfig tun0 destroy
 
 This issue is related to kern/116837.
 
 Leonardo, you can try the patch attached to that pr.
 
 -- 
 Mikolaj Golub