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Comment Re: Slap on the wrist (Score 1) 494

The whole issue is based on ethics of business. If they are willing to cheat the emissions, what else are they willing to cheat? It breaks trust between the regulators, governments and customers.

Worse now, there are over what, over a million people driving around in cars that are operating illegally. What happens now? Do they get a special pass and let the cars keep operating? Will they be allowed to legally transfer then to another owner? Or will they be forced to update the computer and possibly face the possibility of reduced performance and fuel consumption, essentially gimping the vehicle. The best approach would be to suspend all VW diesel sales, grandfather in all the cheat cars and slap the shit out of VW. It's a good compromise which protects the consumer and punishes the manufacturer.

Comment CCTV (Score 2) 212

Few things here.

First, i'd be more worried about the neighborhood locals. What is the neighborhood ethnic makeup? If it's mostly black and you aren't black, then I'd be weary. If it's white trash and you're not white, I'd also be weary. Same for everyone else.
*Blend in. Don't wear fancy clothes, iPod accessories or anything that is valuable. Don't flaunt wealth. If some destitute drug addict sees you, you're a big juicy target.
*Ditto for gang members looking at an outsider. They most likely will rob you to exert power over you. They want you to be a cowering victim. You most likely wont get your ass kicked if you just act scared and give then what they want.

I'v been robbed at knife and gunpoint when I went to high school in Jamaica, Queens. It was a primarily black neighborhood and during freshman year I was a frequent target being a white kid. It was more a joke for them, robbing the lone white kid of two or three dollars and laughing at me. I learned to make friends with kids who took my bus so when we got off or walked to it, we rolled deep. After that no one ever went near me again. Also, don't be a hero. Even if you think some fighting classes are worth it or your a big guy, just don't be dumb. A gun doesn't care and neither does a drug addict.

I'm assuming you will be renting an apartment? Cameras are your best friend. Setup a few hidden inside cameras inside which will catch someone wandering around tearing up the place looking for valuables. Keep them low and head level if you can. A raspberry pi and web cams will satisfy your Linux craving if you go that route. Use a big USB key, 128GB+ to record on a loop. That or get fancy and make a cloud setup for remote access and recording.

Make it look like someone is home. A light coming on if a loud noise is made or window/door is touched will help. Arduino project perhaps? Maybe send a text if an event comes through. Then use your phone to connect to your web cams to have a look around. The sound of a dog barking is also pretty damn good. Get a big ass dog if you can. No crack head wants to mess with a dog. Dogs, and good outdoor lighting are the best security if you ask me. Plus, you can walk the dog to stores and no one will mess with you.

Oh, and leave some money laying around in your house. Most break-ins are by drug addicts. If you have 60 bucks on the kitchen table, hopefully that is all they want and they will get the hell out. Keep smaller electronics out of sight like gaming systems laptops and tablets. They go for the low hanging fruit. My friend had his car broken into in a real bad area populated by homeless drug addicts. The back of his car was all computer boxes will Dell and HP printed on them as he was a travelling service tech. They broke his window and stole his ashtray which had a few bucks in cash and a bunch of change. Didn't take one box or the fancy radio. They don't want to fence or pawn shit if they can get cash. Drug dealers take cash only.

Comment Re:And your favorite, hobby laser cutter is... (Score 1) 28

Up your cutting pressure and what that does. A cheap air compressor can be had from one of those Chinese junk importers (In the states we have a chain called Harbor Freight).

Normally, the cutting assist jet is a nozzle that encloses the lens or isolated form the lens via a sacrificial cover glass. The gas jet is in parallel with the beam and the lens is kept free of contamination due to the cavity in the nozzle being at a high positive pressure. Sounds like you assist jet is external and designed to be aligned with the focal point of the beam. Even tough you have a cheap setup, doesn't mean you cant tweak it to perform better.

Comment Re:And your favorite, hobby laser cutter is... (Score 2) 28

check your Focal length and focus height. If you have a very short focal length the the beam is very fat a few mm or less from sharp focus. Try to get sharp focus at the center line of your material and see how that cuts. Worse case is you will need to compensate for the depth of the bevel in your cad program and then sand it down. If you can, go for a longer focal length lens. Another idea is to check the air assist pressure, might be too low. At work we typically run 5.5 - 7 bar (~80-100 psi). Big cutting shops run really high pressure, upwards of 34 bar or more. BTW, focal length is from the center line of the lens so measure from there. Our lenses range from 100mm to 300mm depending on what we need the beam to do.

Reference: I work in an electron beam and laser welding/cutting shop.

Comment Re: Really? (Score 1) 485

You want horrible? Try the fact that the Acer laptop my grandmother bought and then have to me after she decided computers weren't her thing has a severely limited BIOS. I can't control any CPU features such as enabling Intel vt or controlling hyper threading. Nothing. Just the boot order and a few other basics. Never have I been so pissed at a piece of hardware. That last line may be a lie.

Comment Re:IOMMU is still missing. (Score 1) 49

...except that their drivers don't use it. Yes, there's a IOMMU in modern CPU. No, current GPU drivers don't use it fully. (According to several source about this proof-of-concept neither Nvidia's nor AMD's drivers do properly use IOMMU to isolate de GPU. They basically just grant the device wholesale access to the memory).

I misunderstood you due to bad verbiage: "No, current GPU drivers don't use it fully." The driver has nothing to do with enabling the IOMMU.
The IOMMU automatically maps a device into its own virtual address space. This prevents a random device from reading arbitrary memory outside of its virtual space. The kernel then uses a table provided by the IOMMU to figure out where things actually are in physical address space. BUT if a driver for that device allows it to read random memory locations, then there is a problem. I assume this stems from the newer GPGPU and HSA functionality which aims to reduce overhead by allowing the video card to read certain memory locations directly instead of copying.

The driver does not have to enable the IOMMU, that is automatic. The driver lives in kernel space and from there can do what it damn well pleases in terms of reading/writing memory if the developer inserts such functionality. The driver isn't disabling the IOMMU or failing to enable it, it is allowing the malicious code to read arbitrary memory through vulnerabilities at the kernel level. This bypasses the IOMMU, not disables it. The only protection would be to better enforce memory access privileges in the kernel and/or remove the arbitrary memory access problem.

A good analogy would be a quarantine facility with individual outer doors for each room, each of which is occupied by a single patient (a device). Patients can come and go as they please using their doors. But inside the facility, there is a hall which connects all of the rooms via a locked door for each room (IOMMU). Patients cant open that door but someone with a key can (the kernel). From the hall, a nurse can visit any patient(driver). But a patient can not leave the room through the locked door without that nurse. This isolates the patients from each other. *BUT* if the patient fools the nurse into allowing them into the hall, or the nurse allows them to wander out of the door, then all bets are off. That is what is happening here, the malicious code running on the GPU is fooling the nurse (driver) into leaving the room and wandering into another.

The kernel is the weak spot of any OS. It marshals userspace code and prevents it from reading arbitrary memory and segments users. But once inside the kernel, code can do whatever the kernel allows which is pretty much anything. I can write a module that allows arbitrary memory access from userspace if I wanted.

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