Re: port-xen/47057: Xen NetBSD DomU file system trash under Linux Dom0

[Roger Pau Monné <roger.pau%citrix.com@localhost>]

The following reply was made to PR port-xen/47057; it has been noted by GNATS.

From: =?ISO-8859-1?Q?Roger_Pau_Monn=E9?= <roger.pau%citrix.com@localhost>
To: Manuel Bouyer <bouyer%antioche.eu.org@localhost>
Cc: "gnats-bugs%NetBSD.org@localhost" <gnats-bugs%NetBSD.org@localhost>,
        "port-xen-maintainer%netbsd.org@localhost" 
<port-xen-maintainer%NetBSD.org@localhost>,
        "gnats-admin%netbsd.org@localhost" <gnats-admin%NetBSD.org@localhost>, 
"netbsd-bugs%netbsd.org@localhost"
        <netbsd-bugs%NetBSD.org@localhost>, "royger%netbsd.org@localhost" 
<royger%NetBSD.org@localhost>
Subject: Re: port-xen/47057: Xen NetBSD DomU file system trash under Linux
 Dom0
Date: Sat, 20 Oct 2012 20:34:16 +0200

 On 20/10/12 18:42, Manuel Bouyer wrote:
 > So both cons and prod would be corrupted. As the domU is supposed to update
 > rsp_cons only, I guess we're looking for something that is writing to
 > random memory.
 > 
 > Maybe the atached patch will help; anything trying to write to the page
 > outside of xb_read and xb_write should get a page fault.
 
 I'm sorry to say that the patch didn't seem to help, here is another
 output with your patch applied. It seems like prod and cons gets
 overwritten with random data.
 
 xenbus_xs (process_msg:763) xb_read hdr 0.
 xb_read: cons: 3521 prod: 3523
 Finished read of 2 bytes (0 to go)
 xenbus_xs (process_msg:776) xb_read body 0.
 xenbus_xs (process_msg:811) process_msg: type 6 body 4.
 xenbus_xs (read_reply:134) read_reply: type 6 body 4.
 xenbus_xs (xs_talkv:224) read done.
 xenbus_xs (xs_talkv:202) write msg.
 xenbus_xs (xs_talkv:204) write msg err 0.
 xenbus_xs (xs_talkv:212) write iovect.
 xenbus_xs (xs_talkv:214) write iovect err 0.
 xenbus_xs (xs_talkv:222) read.
 xb_read: cons: 3523 prod: 3546
 Finished read of 16 bytes (0 to go)
 xenbus_xs (process_msg:763) xb_read hdr 0.
 xb_read: cons: 3539 prod: 3546
 Finished read of 7 bytes (0 to go)
 xenbus_xs (process_msg:776) xb_read body 0.
 xenbus_xs (process_msg:811) process_msg: type 16 body ENOENT.
 xenbus_xs (read_reply:134) read_reply: type 16 body ENOENT.
 xenbus_xs (xs_talkv:224) read done.
 xenbus_xs (xs_talkv:202) write msg.
 xenbus_xs (xs_talkv:204) write msg err 0.
 xenbus_xs (xs_talkv:212) write iovect.
 xenbus_xs (xs_talkv:214) write iovect err 0.
 xenbus_xs (xs_talkv:222) read.
 xb_read: cons: 3546 prod: 3565
 Finished read of 16 bytes (0 to go)
 xenbus_xs (process_msg:763) xb_read hdr 0.
 xb_read: cons: 3562 prod: 3565
 Finished read of 3 bytes (0 to go)
 xenbus_xs (process_msg:776) xb_read body 0.
 xenbus_xs (process_msg:811) process_msg: type 7 body OK.
 xenbus_xs (read_reply:134) read_reply: type 7 body OK.
 xenbus_xs (xs_talkv:224) read done.
 boot device: xbd0
 root on xbd0a dumps on xbd0b
 Your machine does not initialize mem_clusters; sparse_dumps disabled
 /: replaying log to memory
 root file system type: ffs
 Sat Oct 20 17:01:27 UTC 2012
 Starting root file system check:
 /dev/rxbd0a: file system is journaled; not checking
 /: replaying log to disk
 swapctl: setting dump device to /dev/xbd0b
 swapctl: adding /dev/xbd0b as swap device at priority 0
 Starting file system checks:
 Setting tty flags.
 Setting sysctl variables:
 ddb.onpanic: 1 -> 1
 Starting network.
 /etc/rc: WARNING: $hostname not set.
 IPv6 mode: host
 Configuring network interfaces: xennet0.
 Adding interface aliases:.
 Building databases: dev, utmp, utmpx.
 wsconscfg: Cannot open `/dev/ttyEcfg': Device not configured
 wsconscfg: Cannot open `/dev/ttyEcfg': Device not configured
 wsconscfg: Cannot open `/dev/ttyEcfg': Device not configured
 wsconscfg: Cannot open `/dev/ttyEcfg': Device not configured
 Starting syslogd.
 Mounting all filesystems...
 Clearing temporary files.
 Checking quotas: done.
 swapctl: setting dump device to /dev/xbd0b
 Starting virecover.
 Checking for core dump...
 savecore: no core dump
 Starting local daemons:.
 Updating motd.
 Starting powerd.
 Starting sshd.
 postfix: rebuilding /etc/mail/aliases (missing /etc/mail/aliases.db)
 newaliases: warning: valid_hostname: empty hostname
 newaliases: fatal: unable to use my own hostname
 /etc/rc.d/postfix exited with code 1
 Oct 20 17:01:46  postfix/sendmail[494]: fatal: unable to use my own hostname
 Starting inetd.
 Starting cron.
 The following components reported failures:
     /etc/rc.d/postfix
 See /var/run/rc.log for more information.
 Sat Oct 20 17:01:46 UTC 2012
 Oct 20 17:01:48  getty[589]: /dev/ttyE2: Device not configured
 Oct 20 17:01:48  getty[569]: /dev/ttyE3: Device not configured
 Oct 20 17:01:48  getty[501]: /dev/ttyE1: Device not configured
 
 NetBSD/amd64 (Amnesiac) (console)
 
 login: root
 Password:
 Oct 20 17:02:51  login: ROOT LOGIN (root) on tty console
 Last login: Sat Oct 20 16:06:11 2012 on console
 Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
     2006, 2007, 2008, 2009, 2010, 2011, 2012
     The NetBSD Foundation, Inc.  All rights reserved.
 Copyright (c) 1982, 1986, 1989, 1991, 1993
     The Regents of the University of California.  All rights reserved.
 
 NetBSD 6.99.14 (XEN3_DOMU) #2: Sat Oct 20 18:50:37 CEST 2012
 
 Welcome to NetBSD!
 
 Terminal type is vt100.
 We recommend that you create a non-root account and use su(1) for root
 access.
 # cd src
 # while [ 1 ]; do
 > ./build.sh -j3 -m amd64 -O ../obj -T ../tools build >log
 > done
 xb_read: cons: 706764616 prod: 2607
 xb_read EIO
 xenbus_xs (process_msg:763) xb_read hdr 5.
 panic: XENBUS error 5 while reading message
 
 fatal breakpoint trap in supervisor mode
 trap type 1 code 0 rip ffffffff8012e655 cs e030 rflags 246 cr2
 7f7ff780c390 ilevel 0 rsp ffffa0002e4c5b30
 curlwp 0xffffa00002367980 pid 0 lid 32 lowest kstack 0xffffa0002e4c2000
 Stopped in pid 0.32 (system) at netbsd:breakpoint+0x5:  leave
 breakpoint() at netbsd:breakpoint+0x5
 vpanic() at netbsd:vpanic+0x1f2
 printf_nolog() at netbsd:printf_nolog
 xenbus_thread() at netbsd:xenbus_thread+0x140
 ds          7980
 es          5b70
 fs          100
 gs          b880
 rdi         0
 rsi         d
 rbp         ffffa0002e4c5b30
 rbx         104
 rdx         0
 rcx         8
 rax         1
 r8          ffffffff8063d600    cpu_info_primary
 r9          1
 r10         0
 r11         ffffa0000238c000
 r12         ffffffff804adee8    copyright+0x3bae8
 r13         ffffa0002e4c5b70
 r14         ffffa00002367980
 r15         c2c2c2c2c2c2c2c2
 rip         ffffffff8012e655    breakpoint+0x5
 cs          e030
 rflags      246
 rsp         ffffa0002e4c5b30
 ss          e02b
 netbsd:breakpoint+0x5:  leave
 db{0}>