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

[Roger Pau Monné <royger%NetBSD.org@localhost>]

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

From: =?UTF-8?Q?Roger_Pau_Monn=C3=A9?= <royger%NetBSD.org@localhost>
To: Manuel Bouyer <bouyer%antioche.eu.org@localhost>
Cc: =?UTF-8?Q?Roger_Pau_Monn=C3=A9?= <roger.pau%citrix.com@localhost>, 
        "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>
Subject: Re: port-xen/47057: Xen NetBSD DomU file system trash under Linux Dom0
Date: Sun, 21 Oct 2012 19:47:38 +0200

 --bcaec54ee10a2dcbb804cc9555ff
 Content-Type: text/plain; charset=UTF-8
 
 On Sun, Oct 21, 2012 at 1:29 PM, Manuel Bouyer 
<bouyer%antioche.eu.org@localhost> wrote:
 > OK, here's another patch, which also checks that the mapping doesn't
 > change. But I wonder is the corruption occurs on the NetBSD side.
 > Could you also add some debugging code on the other side ?
 
 Still no luck with the new patch, I've been looking at the Linux code,
 and the attached patch (taken the idea from Linux) mitigates the
 problem, but we still have it. I've also added the trace and verbose
 options to xenstored running in the Dom0, and there's no sign that
 anyone is writing to xenstore when the crash happens.
 
 Is it possible that someone writes to the machine address
 xen_start_info.store_mfn and is there anyway to check that nobody is
 mapping this ma to another va?
 
 --bcaec54ee10a2dcbb804cc9555ff
 Content-Type: application/octet-stream; name="patch.diff"
 Content-Disposition: attachment; filename="patch.diff"
 Content-Transfer-Encoding: base64
 X-Attachment-Id: f_h8kg24l21
 
 ZGlmZiAtLWdpdCBhL3N5cy9hcmNoL3hlbi94ZW5idXMveGVuYnVzX2NvbW1zLmMgYi9zeXMvYXJj
 aC94ZW4veGVuYnVzL3hlbmJ1c19jb21tcy5jCmluZGV4IDA0ZTRmMDIuLjllMjUzMDcgMTAwNjQ0
 Ci0tLSBhL3N5cy9hcmNoL3hlbi94ZW5idXMveGVuYnVzX2NvbW1zLmMKKysrIGIvc3lzL2FyY2gv
 eGVuL3hlbmJ1cy94ZW5idXNfY29tbXMuYwpAQCAtMTMzLDYgKzEzMyw3IEBAIHhiX3dyaXRlKGNv
 bnN0IHZvaWQgKmRhdGEsIHVuc2lnbmVkIGxlbikKIAkJcHJvZCA9IGludGYtPnJlcV9wcm9kOwog
 CQl4ZW5fcm1iKCk7CiAJCWlmICghY2hlY2tfaW5kZXhlcyhjb25zLCBwcm9kKSkgeworCQkJaW50
 Zi0+cmVxX2NvbnMgPSBpbnRmLT5yZXFfcHJvZCA9IDA7CiAJCQlzcGx4KHMpOwogCQkJcmV0dXJu
 IEVJTzsKIAkJfQpAQCAtMTgwLDYgKzE4MSw3IEBAIHhiX3JlYWQodm9pZCAqZGF0YSwgdW5zaWdu
 ZWQgbGVuKQogCQl4ZW5fcm1iKCk7CiAJCWlmICghY2hlY2tfaW5kZXhlcyhjb25zLCBwcm9kKSkg
 ewogCQkJWEVOUFJJTlRGKCgieGJfcmVhZCBFSU9cbiIpKTsKKwkJCWludGYtPnJzcF9jb25zID0g
 aW50Zi0+cnNwX3Byb2QgPSAwOwogCQkJc3BseChzKTsKIAkJCXJldHVybiBFSU87CiAJCX0K
 --bcaec54ee10a2dcbb804cc9555ff--