Follow Slashdot stories on Twitter


Forgot your password?
Check out the new SourceForge HTML5 internet speed test! No Flash necessary and runs on all devices. ×

Comment Re:Pointless hype (Score 1) 343

if you want to increase the signature of the stealthy aircraft there are lots of easy ways

You missed: open the weapons bay doors, which the F-35 has to do every 10 minutes or so if it wants to avoid cooking it's munitions. Quoting that link:

  • The F-35's weapons bay can overheat if if the plane is maintaining high speeds at an altitude of under 25,000 feet and an atmospheric temperature 90 F or greater. The trouble occurs if the plane's weapon day doors are closed for upwards of 10 minutes, and opening the bay doors negates the F-35s stealth capabilities.

Has Physics Gotten Something Really Important Really Wrong? ( 387

Slashdot reader schwit1 quotes an article from NPR: Some researchers now see popular ideas like string theory and the multiverse as highly suspect. These physicists feel our study of the cosmos has been taken too far from what data can constrain with the extra "hidden" dimensions of string theory and the unobservable other universes of the multiverse... it all adds up to muddied waters and something some researchers see as a "crisis in physics."
The article quotes Roberto Mangabeira Unger and Lee Smolin, the authors of a new book arguing that "Science is corrupted when it abandons the discipline of empirical validation or dis-confirmation. It is also weakened when it mistakes its assumptions for facts and its ready-made philosophy for the way things are." And according to this analysis of the book, what they're proposing is "to take a giant philosophical step back and see if a new and more promising direction can be found. For the two thinkers, such a new direction can be spelled out in three bold claims about the world. There is only one universe. Time is real. Mathematics is selectively real."

Comment Re:"Trusted" (Score 1) 368

Why do you trust the main CPU, if you don't trust the ME chip?

Because hardware designers making the odd mistake is just normal. I've spent a fair portion of my life papering over their mistakes, always successfully. But to fuck things up beyond redemption; that requires a computer programmer - just ask the patients treated by Therac 25.

Comment Re:I assumed this was already a default (Score 2) 924

A multi-user system shouldn't allow unpriviledged users from consuming resources indefinitely. It's too easy to starve a system or resources. I think that's one of the reasons behind the isolation dockers provides in the first place. Shut down the container and everything gets cleaned up.

What "multi-user systems"? Multi-user systems died somewhere around the turn of the century, when the personal computers became common.

Secondly the people whinging about there do not give a shit about your concerns over large computer systems. And you should listen to them, because they are the people who run those systems. They are the sysadmins in charge of large clusters of machines they control with the likes of ssh, ansible and puppet. If there is a task left running when they log out, it is because they wanted it to be running.

All that aside, this is not 'nix having some issue with leaving processes running indefinitely when a person logs off. I've used 'nix of one version or another since V6 - and even back then it had a solution. When the user logged out, a SIG_HUP signal (so named because back then it was trigged by a modem hangup) was sent to all processes started by that login, and they were killed. So it's been a solved problem for 30 years.

The current problem is the caused by desktop guy's themselves. All the processes that drive their windowing systems needed to communicate, so they created one. Actually they've created several - corba, dcop, and now dbus. Initially they were used for communication configuration changes and such - eg, when you change the desktop font size everyone knew about it immediately, so the entire screen just changed. Then they found new uses for their toy - and soon it is used to communicate to backend daemons to do thing like bringing network interfaces up and down, which often required new processes to be created. That was followed by "address book servers", and "wallet servers" and god knows what else. In doing so they managed to break the old SIG_HUP system for desktop users, because their sometimes new processes weren't spawned by child processes of the login - they were instead spawned by system daemons.

So the desktop guys created a problem for themselves (only). The rancour you see here is the solution they have implemented and forced down everyone's throats breaks existing stuff. This is just laziness. If they insist on designing systems that have background daemons spawning per-session processes they could go to the effort of, you know, tracking them, so they can kill the bloody things when the session ends. Tracking things is after something computers do real well. Yes it would be more work - but they created the problem.

That said - if they were to go to the effort of accommodating legacy stuff (which they did in an exemplary way for the change from SysV init to to systemD init) by say offering up patches to the few programs that do leave stuff running in the background (nohup, term, screen, ...) I still wouldn't be satisfied. That is because what they have put together is a godawful mess, and this "solution" typifies it.

The first time I noticed the winding IPC monster was starting to grow is vim complained it could not save its settings ... when I was running it on a remote machine. wtf? Turned out they had pushed the tentacles of this mechanism to a remote VIM, and it was trying to save its settings on my laptop. Then ssh stopped shutting down properly - turned out because they weren't closing the IPC tunnels they had built. Then network connections started mysteriously changing their configuration - because the desktop had told network-manager who told a dhclient to do something with a virtual network device I had just created - wtf? It has since become evident that where before I could see state of my machines in static text files in well known places usually put there by me, now it was configured by inscrutable ephemeral messages being transmitted between daemons I didn't know had been started and don't write their state anywhere.

Although I have deep misgivings about this design, it ain't an area I'm interested in so I'm willing to concede it may be all necessary to make a desktop machine work. And to be fair, for your average desktop user who can't fix it if it all goes wrong anyway, it doesn't matter if underneath it's plumbing is complex mess only it's creator could understand. But for fucks sake keep this shit out of my domain - which is large clusters of machines that must be up 24 hours a day, 365 days a year - or I have my arse served to me on a plate. This "fix" is a typical example of then not doing that.

Comment Re:The Intel 1915 GPU Gen9 driver finally works! (Score 1) 149

And then there are people that just refer to the definition of what "booting an OS" means, instead of doing silly games.

I suspect we are from the same generation. When the term OS was owned by computer programmers, you had a point. We studied books on how to write operating systems. They sat at a very specific place in the software stack.

That meaning was subsumed when popular culture conscripted the term OS to mean Windows, Android, iOS or whatever. Even Wikipedia uses it in this way. In todays nomenclature after the OS boots, you use it to run "apps" - usually by clicking or tapping things. When you upgrade the OS, you upgrade the entire stack. Nowadays OS could reasonably be defined as the software waiting for you to do something after you power the the device on. If your laptop boots into X and then waits - running X is most definitely part of the boot process. If it doesn't run X, then obviously X isn't part of the boot process - but userspace programs that configure the network, run ssh deamons and display login prompts most definitely are.

Today we use terms like "kernel" where we would have used OS years ago. I thought you were playing word games - but maybe you haven't caught onto how popular culture has re-purposed a term we used to consider our own.

Comment Re:The Intel 1915 GPU Gen9 driver finally works! (Score 1) 149

Incidentally, you cannot boot into X, that is just some userspace-stuff your distro is doing to fake it. Boot is long over at that time.

If you are going to play that game, I've written BIOS's. Grub was my userspace. By your standards the kernel is so far removed from where the real action is, it could hardly be considered relevant to booting.

(I'm sort of hoping Intel's microcode guys pop up here, and tell us both we are so far away from the real metal we may as well be discussing how Kubernetes gets it's config from etcd. They'd be wrong of course. The machine ain't up until I can Google something.)

Comment The Intel 1915 GPU Gen9 driver finally works! (Score 4, Informative) 149

Please, for the love of $deity, lets this be true. We've been putting up with broken video on, well, just about every Intel GPU since they stated their driver update for Gen9 (Skylake). And that includes older hardware that used to work before this effort was started. I can understand the occasional glitch in a new kernel, but "doesn't boot into X, at all, ever" isn't just a glitch - and it's been going on for 5 kernels so far. Currently in 4.5 I can't reliably attach a second monitor.

What amazes me is this isn't just Linux. The net was full of people complaining the video their brand new Windows laptop ranges from slow to utterly unusable. Naturally they said are going to get it fixed under warranty. Ha! It infests everything. The BIOS on my laptop can't initialise a second monitor either.

It is getting better. 4.2 didn't boot for me. 4.5 works acceptably on one screen. The i915's bugzilla reports my current two monitor problem is fixed. Hell, maybe I'll be able switch on full GPU power saving in 4.7! But is it really this hard?

Comment It happens every day (Score 4, Insightful) 298

Here is a graph of electricity prices where I live for the current day: Note the red line (whole sale price) drops off the bottom graph in the small hours of the morning. It's negative.

At least were I live it has nothing to do with renewables (the sun ain't shining at that time after all). Oddly it is because coal plants suffer the same problem renewables - they can't control the power quickly. No one is using power at the coal plants are producing at 3 AM so there is an oversupply, and it's costs more to shut the plant down for the hour or so than it does to pay people to find ways to use it.

This happens just about every fucking day! How is this news?

Comment Re:It's a 5C (Score 1) 286

Anyhow the price for making the SE sw write-once is that you could have to recall, scrap and replace an entire production run (as in million of units).

No, it's doesn't have to be that serious. The price is the Secure Enclave destroys the secrets it's guarding before allowing an upgrade. In effect, it's the same as purchasing a new phone.

Even if it is was you say, there is always another alternative - live with the bug. It is after all a question of what you consider to be the biggest bug - your privacy stuff not being really private, or the remote chance you turn the phone off after a few failed password attempts.

Using actual ROMs or PROMs would be an effective defense, but those are getting pretty rare these days.

On the contrary, they are the cheapest way to place firmware on a chip. And more to the point, something has to boot the chip to the point it can load real firmware. If you allow whatever does that booting to upgraded, you are also allowing it to be corrupted and the device (CPU, phone, or whatever) to be bricked. How many bricked CPU's have you seen? I'd wager none. That's because they all have ROM. It's not rare at all.

Comment Re:It's a 5C (Score 1) 286

Do you *really* want law enforcement to build the capacity to attack the silicon?

It's expensive - far more expensive than getting a judge to sign a piece of paper. And it's not easy. In fact it's very, very hard. The security of SIM's, Credit and Debit cards, pay TV encryption, ATM's and a long list of other things rely on silicon guarding it's secrets. If you don't have several million, a gear normally found only in Uni's and chip manufacturers, a few PhD's and months of time it's out of the question.

So, no I don't want it. And I'm not particularly worried about them building it.

Comment Re:It's a 5C (Score 1) 286

That's not the solution - Apple needs to be able to update the Secure Enclave firmware too, it's too complex to be reasonable to bake into a ROM forever.

TPM's are more complex, simply because the solve a more general version of the same problem. Billions have been sold, and most of them have got along just fine without a firmware upgrade. We do know how to get bugs below 1 per 100k LOC, and I have no doubt Apple is capable of it. It's not cheap, but I doubt the expense concerns them overly.

Comment Re:It's a 5C (Score 1) 286

You can't update the security enclave as it is flashed once and then it burns a circuit that makes it impossible to update again.

Source? It would be nice if it was true, but if it's true I'd expect to hear Apple trumpeting it from the roof tops. As far a I know, Apple have never said anything publicly. The reference document they publish on security says nothing about firmware upgrades for the Secure Enclave.

Comment Re:It's a 5C (Score 1) 286

that's why the 5S and newer have Secure Enclave.

And Apple also knows the Secure Enclave can be by-passed too, by anybody who has the firmware signing key. If you have it, you just upload new firmware bypassing the checks. Currently only Apple has it of course. But that is where this all started.

Still, they should make the FBI rue the day they tried to destroy Apple's market,

Which is real simple to do. Put the Secure Enclave firmware in ROM, so it can't be upgraded. Then it becomes truly uncrackable from software, so the LEA's would be reduced to attacking the silicon. It's their worst nightmare.

This is possible because the SecureEnclave is stand-alone, and compared iOS itself it is almost trivial. It's unlikely the API it provides is ever going to change. Besides, there is a public standardised API for such things: TPM 2.0. (Not that Apple's into standards, but TPM 2.0 is documented and thoroughly vetted, and includes rate limiting for passwords.) The one remaining reason to provide upgrades is to fix a bug, but as the old saying goes "only trivial software contains no bugs", and for someone of Apples resources this, to repeat myself, trivial. Besides in things like Secure Enclave's allowing firmware upgrades IS A BUG.

Comment We already have smaller connector (Score 1) 566

We already have the connector. It has 24 pins, can carry up to 100W, and has 4 dedicated high speed pairs rated up to 40Gbps. It's specification already allows for different signalling to take over the pins in what the spec calls Alternate Modes. There are Alternate Modes for Display Port, MHL and Thunderbolt. These are in addition to the native mode - USB 3.1

It's the USB-C connector of course. The idea of making Ethernet an alternate has already been mooted. Someone just has to do the work to make it happen.

Slashdot Top Deals

Doubt is not a pleasant condition, but certainty is absurd. - Voltaire