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[brettpim]

I thought this might be because I had teapot's aggressive power management activated so I

rm /etc/xo-suspend/aggressive

and I also disabled the screensaver.  But the XO is still going into some kind of sleep/power savings/something and forgetting that it needs to take a picture every minute.

This won't take effect until you reboot the machine.

good point (embarrassed cough :-)

[Rao]

Hello all

I saw the following (at URL http://news.zdnet.com/2100-9595_22-332141.html?tag=nl.e550).

================================================


By David Meyer ZDNet UK
Posted on ZDNet News: Aug 17, 2009 8:33:11 AM
A hole has been found in Linux kernel versions stretching back eight years that is 'as trivial as it can get to exploit', according to the Google employees who discovered it.

Julien Tinnes and Tavis Ormandy, the security researchers who discovered the vulnerability, have already issued a patch for the flaw. According to a blog post written by Tinnes on Thursday, the hole "affects all 2.4 and 2.6 kernels since 2001 on all architectures", and is "the public vulnerability affecting the greatest number of kernel versions".

While the kernel hole allows only local privilege escalation, the vulnerability is widespread, said the researchers.

"The issue lies in how Linux deals with unavailable operations for some protocols. sock_sendpage and others don't check for Null pointers before dereferencing operations in the ops structure," Tinnes wrote. "Instead the kernel relies on correct initialization of those proto_ops structures with stubs (such as sock_no_sendpage) instead of Null pointers."

Tinnes said that, as the vulnerability leads to the kernel executing code at Null, it is "as trivial as it can get to exploit".

"An attacker can just put code in the first page that will get executed with kernel privileges," Tinnes wrote.

In an advisory published on Neohapsis on Thursday, Ormandy wrote that an attacker could exploit the vulnerability by creating a mapping at address zero containing code to be executed with privileges of the kernel, thus triggering a vulnerable operation.

The Red Hat team issued an official mitigation recommendation on Friday, in which they called for the affected protocols to be blacklisted in order to stop Tinnes and Ormandy's publicly circulated exploit from working properly on Red Hat Enterprise Linux.

This article was originally posted on ZDNet UK.

==========================

I would like to know if this affects the XO running Ubuntu Intrepid  because the kernel,
as I understand it, is the  Red Hat Linux (again, as I understand it) kernel from OLPC?

thanks,

Rao

[mavrothal]

I would like to know if this affects the XO running Ubuntu Intrepid  because the kernel,
as I understand it, is the  Red Hat Linux (again, as I understand it) kernel from OLPC?

thanks,

Rao

This affects almost all the linux machines out there. As you can see from RedHat's recommendations for every build you need a different approach. Recent kernels have been already patched but XO-Sugar/Ubuntu is using 2.6.25
Hopefully Teapot (where are you?) and/or the OLPC/SugarLabs teams will address it suggesting the indicated configuration changes/patches. Fedora does not support F9/2.6.25 kernel  anymore so I doubt help will come from there.

[mavrothal]

Some time now, teapot's handy tubewatcher (the one that downloads and plays youtube video) is not working. Before I start pocking around my system can anyone confirm that is working today in their system?
(There are rumors that youtube has change few things and clive (the program the tubewatcher uses) is not doing the job anymore, so if this is the case there is not much I can do about it other than wait for clive update or use another dl utility.)

[GregYohn]

You Tube is discontinuing its support of some of my internet browsers.

Well, looks like we have to live with what the XO can handle on its own. That basically means that I will be waiting on the XO 1.5 to see YouTube.

[mavrothal]

You Tube is discontinuing its support of some of my internet browsers,

Well, looks like we have to live with what the XO can handle on its own. That basically means that I will be waiting on the XO 1.5 to see YouTube.

Right...
But does this mean that you tested your XO-intrepid installation and tubewatcher does not work, or not?...

[metal.lunchbox]

I was also unable to use the TubeWatcher application, but quickly found other solutions. If you are using firefox or opera you can use the userscript Yousabletubefix or other similar scripts to change the way youtube pages are presented. Flashblock is a great tool that will save your browser from having to deal with flash elements and instead you can use the download links provided by the above mentioned users scripts and view the videos in Mplayer. I do this all the time on my xo and have no problems using youtube. Clive might not be working but Youtube-dl. Few people like the Flash player plugin, even those with fast computers. The internet is full of scripts and hacks to avoid using it and still enjoy youtube.

Don't wait for XO 1.5. You can watch all the youtube videos you want on an XO running intrepid, it just takes a little setup.

james

[Sam J.]

I was also unable to use the TubeWatcher application, but quickly found other solutions. If you are using firefox or opera you can use the userscript Yousabletubefix or other similar scripts to change the way youtube pages are presented. ...
Don't wait for XO 1.5. You can watch all the youtube videos you want on an XO running intrepid, it just takes a little setup.

Is Yousabletubfix for youtube only or does it work with flash video on other websites such as nytimes.com? 
If it's for youtube only, do you know of anything that would help viewing nytimes video? 
To use it with opera, is it necessary to first install the flash plugin, and flashblock, or can you use Yousabletubefix alone?

[XOIOWA]

Some time now, teapot's handy tubewatcher (the one that downloads and plays youtube video) is not working. Before I start pocking around my system can anyone confirm that is working today in their system?
(There are rumors that youtube has change few things and clive (the program the tubewatcher uses) is not doing the job anymore, so if this is the case there is not much I can do about it other than wait for clive update or use another dl utility.)

Mavrothal,
I also am not able to make the Tubewatcher work anymore.  I did successfully use it only a small number of times, but that was a long while ago.  Now I've decided to give up on it, and instead I'm using a Firefox plugin.  The one here works pretty well for me:  https://addons.mozilla.org/en-US/firefox/addon/3006

Good luck, and thank you for all your effort on this forum.

[mavrothal]

Thank you XOIOWA, metal.lunchbox
Actually for firefox indeed there is a number of options including the the VLC pluging that actually works fairly OK within the browser. However I prefer Opera that is considerably faster on the XO, hence the need for teapot's handy clive-based tubewatcher.
I guess I'll start pocking...

[john-l]

I was able to successfully use teapot's installation instructions to install Ubuntu on my XO over the weekend.  Thanks very much for putting this together; it makes the laptop far more usable.  I'm very excited about the power management options and the seamless wireless support.  It's the best I've seen of both features in any Linux laptop that I've used.

I bought a "store brand" 8 GB SD class 6 card from Microcenter; the salesperson said that he thought the manufacturer was actually Kingston.  That, and the price being so much better, made it worth the risk.  I also bought a 4 GB Kingston USB thumb drive.  Then I followed teapot's instructions exactly, and everything worked well.  (One hiccup was that I managed to change my password to something strange, but I was able to use the chroot instructions to change it back.)

My primary goal for my XO was to turn it into a reasonable facsimile of an ebook reader.  (I really like the no-backlight display mode.)  The books I'm interested in reading are mainly in PDF form, so I started using ePDFViewer.  It seemed to be lacking in some navigation features, however, so I decided to install and try evince, and I've been quite happy with evince.  evince may be a bit heavyweight in comparison with ePDFViewer, but it still seems quite performant on the XO, and it has a number of features that I greatly value, such as remembering the last page between sessions, paging down with the space bar, and having an overlap between text when paging down.  One thing to note is that you should take evince out of full screen mode before rotating the screen, as it doesn't seem to update after a screen rotation if it is in full screen mode.

While on the the topic of screen rotation, I ran across a few wrinkles.  First, I noticed that screen rotation does not consistently choose the next rotation state, which seems odd.  Second, as a feature request, I would like to have an option to make the screen rotation feature simply toggle between two rotation states.  (This might be implemented as a configuration for masking out certain undesirable rotation states.)

While on the topic of implementation, I was wondering if the various scripts and configuration files that drive the various XO-specific features (e.g. power management and screen rotation, among others) are maintained in version control somewhere.  I did grab the tarball linked in the first post, but I have a sense that teapot has moved beyond that version since then, and I'd like to contribute, if possible.

Getting back to setting up my XO, I also want to use it as a portable Skype station.  The application works, and I can successfully call out, but audio input is still choppy.  I've followed the various guides to choosing the proper device settings, but, to be fair, I do need to do some more testing.  Also, since then I have created a swap file, and that may help.

I decided to create the swap file on the USB thumb drive.  I realize that that is another solid state device, but I feel it is a less critical one.  After enabling the swap file, I do think I've noticed reduced application latency, although it's hard to be sure.  One thing I would like to be able to do is add hooks to the device detection mechanism that automatically turns swap on when the USB drive is plugged in, and turns the swap off before unmounting the USB drive.  I think this would involve two things:

• Interfacing with the subsystem that detects and mounts devices
• Adding the swap activation and deactivation commands to the sudoers file as commands that can be executed without a password

I'm not horribly familiar with either of those mechanisms, so if anyone wanted to work with me on that (or point me to some documentation), it could be fun.

Once again, thanks for the great work on this.

[prchakal]

When i do all the steps and put my usb pendrive on XO Laptop i boot and i receive an error message: KERNEL PANIC - NOT SYNCING: VFS: UNABLE TO MOUNT ROOT FS ON UNKNOW-BLOCK(0,0)

What i do wrong?

or

What i have to do?

[mavrothal]

When i do all the steps and put my usb pendrive on XO Laptop i boot and i receive an error message: KERNEL PANIC - NOT SYNCING: VFS: UNABLE TO MOUNT ROOT FS ON UNKNOW-BLOCK(0,0)

What i do wrong?

or

What i have to do?

The instructions are for an SD card NOT a USB thumb drive.

[kenf]

Hi,

I just tried pressing the frame button, upper right hand corner, and it did not change the screen.

Ken F.

[kenf]

I may not have been clear about this in the previous post.

"Teapot,
Thanks a lot for the customized Intrepid.  Very slick.
Is there a way to get the screen into high-res 200 dpi mode while in Ubuntu,
in order to use the XO as an ebook reader?"
Answer: "Press the "Frame" button in the keyboard's upper right corner."

Pressing the "Frame" button has no effect on the screen. Does it need some special configuration to work?

Ken