but that's not how it is. The bug is still known, we still know how to exploit it, nothing is obscured. (well, maybe to the general populus, but the "hackers" are the important people here and they aren't gonna be fooled by this)
It's nearly impossible in that it's EXTREMELY hard to exploit now, whereas it was fairly simple before.
Alas, they seem to have rewritten this section and removed that. At least I can't find it in any of the online docs for the Pentium. Hrmph... It used to be part of the "Architectural Overview", section 2.0
It's not really practical to do something like that anyway, at least on that scale, BUT the segment descriptors contain a "present" flag exactly like the page table entries.
Even in the old 1992 docs there's not a lot of detail as to how to do this, but I would imagine it would be almost identical to the way virtual paging is done. When a segment register is loaded with a segment whose descriptore is marked "not present," the OS loads the appropriate data into the linear 32-bit address space and continues, probably pushing out a segment that's not in use and clearing its present flag.
Honestly, I don't see how it would even be possible to do that with full 4gig segments, maybe that's why Intel removed it. For smaller segments, it should be possible, though it would mean a LOT of moving things around. (like virtual memory with REALLY big pages)
"Memory is organized into one or more variable length segments, each up to four gigabytes (2^32 bytes) in size. A segments can have attributes associated with it which include its location, size, type (i.e., stack, code or data), and protection characteristics. Each task on an Intel486 microprocessor can have a maximum of 16,381 segments, each up to four gigabytes in size. Thus each task has a maximum of 64 terabytes (trillion bytes) of virtual memory."
I believe the trick is to mark segment registers as invalid and use some of the free bits in the descriptor to tell the OS where to load it from. When the program tries to access that segment, an exception is generated which allows the OS to swap in the appropriate data. It's much like virtual memory is usually done, but using the segment registers as "super" pages.
the physical address is LARGER than 32 bits. It is 36 bits on Wmt.
It's just a matter of how statistics work. People dying at a very young age will skew the average a lot more.
If you have 10 people that all live to be 50, the average is 50. To drop the average to 45 you need to kill off about:
age # of people
birth 1
25 2
33 3
37 4
40 5
41 6
42 7
43 8
44 9
45 10
Clearly those dying very young have a much greater impact.
Yes, but you still need to get the packet in question processed in the right part of AIM. Previously, these could be sent normally through the service from another user. Now, you somehow have to slip it into the communication stream, afaik this means using some sort of packet sniffer to find and monitor the connection for a while at least.
This is not security through obscurity, it's taking a trivial exploit and making it nearly impossible. I should hope they're also working on fixing the actual buffer overflow, but for now, and for users who don't upgrade (or don't know how) once this is done, it's much less of a concern.
I just saw Sun E250s being sold for $1750 today that were $15,000 a year and half ago. Not a bad deal for the user, a major disaster for Sun.
Why doesn't Sun just buy them back? They could still make money off the deal, then refusbish them or recycle parts and sell it again, back at full (or slightly reduced) price. Plus, they've already made money in the first place.
With 32-bits, you should be able to access 4gigs of memory, I assume there's something in the system that uses one bit as a flag to limit it to 2 gigs.
If you *really* need more memory, using segment registers (on 386 even) will give you 46 bits, for 64 terabytes (per task btw, not total). But that's not linear, and it's VIRTUAL, not PHYSICAL memory. The hardware address bus is still only 32 bits wide (well, technically a bit less, but only because memory isn't arranged in bytes), so you can still only access 4 gigs of physical ram without EXTREME ugliness.
Of course it's good for the hardware vender, they get to sell more stuff, and it's good for the software developers because they don't have to work as hard to support the older hardware.
So is that your point? Fortunately for Apple it requires a better computer, but unfortunately for the users they won't get as much work out of older systems with it? That's fine, but why should we concern ourselves with what's good for Apple?
I got XP Pro(for free) and didn't think I would like or even need it. But after using it for a month now, I can say it has NEVER crashed and is now my only desktop OS.
If the OS still functions perfectly after a year of patches and hardware upgrades, then I will be impressed. 2k has been pretty stable for me, except for problems that slowly seeped in after about 4 months which I've been to busy to try to locate or fix.
That's the unfortunate part about the system getting more stable, it takes longer to know just how stable it is...
OSX requires a bit.. more. Fortunately and unfortunately.
How is an OS that uses more processor power fortunate for the end user? The extra features are definitely a benefit, but I don't see how extra requirements are.
When you can't get the best programmer in each field to design/program each element there's bound to be duplication as new versions are written that behave (either in function or interface) in what is percieved to be a superior way. If evolution works for software then the best code will eventually be borrowed for other projects or just generally used more. In other words, if several different wheels are invented simultaneously across the globe, the optimal wheel is more likely to be found.
Also remember that the software is not the only output of programming. There's also the additional experience and skills gained by the programmer.
It is, in fact "some bizarre magic," so to speak, not because we do not understand it, but because it requires considerable algorithmic search to find such an efficient (quick, small and effective) state through which the machine can produce its effect - its magic in the same sense that a chess playing program is magic.
My point is that the mechanism is understood, but the actual process is not. They know vaguely *what* is hapenning, just not exactly *how*.
The insight that you fail to grasp is that with this technique, we can take advantage of those variables that you say we should eliminate, making designs better.
That's not what I said. What I said is that it is usually eliminated because it's hard to calculate. Nothing about *should*. You seem to have failed to grasp the distiction.
As far as complexity, what kind of bacteria are you thinking of that its so far from?
Any kind? This circuit can detect between two tones. I'd say bacteria can do MUCH more complex things than that.
1. This will not lead to intelligent machines that will try to make you into toast. This is not even close to the sort of complexity of evolving bacteria.
2. The reason he doesn't understand how it's working is because the design is using the interference generated in one part of the chip someplace else. Conventional designs try to eliminate this because it's so complex to predect. This is not a matter of "some bizarre magic is happenning that we don't understand and it will probably turn us all into pools of gravy."
These don't count for new computers for home users. Typical home users have one computer, and this is it. It's useful for some people (me, for example), but not most.
The sheer waste of burning a 660/700MB CDR to transfer a 1MB or less file. ..and CD-RW doesn't count, not all drives can READ a CD-RW
Now that's a shame... current drives should be able to read CD-RW.
Personally, I usually use ethernet to transfer files, but the many home users don't even have the problem to begin with.
It's largely the trackball (why does everybody hate these?)
Trackballs require fine motion control with the thumb, mice use the whole hand/arm/wrist. Unless you're naturally predisposed for it, trackballs are much harder to use without practice.
but also the total lack of desktop icons and reorganised Windows Start menu
Man, I'd hate to see someone else try to use my computer... I've got a VWM, a command box, and keyboard shortcuts. No icons, no taskbar, no start menu. heh. Gotta love LiteStep. (luckily this is my home computer...)
Stars are huge and far away, but human technology and science can reduce them to pictures for your PC desktop. Who is more powerful than who in this case?
Well, in a star vs scientist fight, I'm still betting on the star. Sure, we can reduce the star to a pretty picture, but the star can reduce us to plasma.
...not to mention the possibility of intelligent life around these distant stars. Given our level of knowledge about the universe, those impressed by it can say "we are nothing in comparison," but no one can say "we're the best there is" simply because there's so much that we don't know that could be out there.
Fine, all the vastness and stuff doesn't impress you, but don't get cocky for it.
Keep in mind that many game developers simply license the engine and modify it, so they *can't* do this. Now if the people who wrote the engine open-sourced that first, then they could, but that's harder since the engine will make money long after the game has stopped.
Just out of curiosity, do these filtering things look for every possible executable extension? Wouldn't it be better to check if the first two letters are "MZ" to tell if it's executable? (or rather, if they're not MZ then it's not executable)
I can't believe it takes an AC to realize that user interface design != programming. In general, programmers are very bad at UI design because they understand the system too well and the user not at all. (unless they're designing software tools...)
This isn't a "nerds vs cruel world" thing, it's a matter of comunication. The computer needs to communicate with the users. The developer is in charge of how the computer communicates. Nobody is really in charge of how the user communicates. Whoever designs the UI needs to understand some of how the computer works and more of how the user works. Not easy...
Remember when you had to purchase Netscape, but IE was free?
No, I was a student back then. How is this relevant anyway? (Remember when IE TOTALLY SUCKED?) So MS had deeper pockets than Netscape. So what? How much do you have to pay for mozilla?
MANY windows programs do this, notably ones with using MDI. MS Word for example, you'll notice on the right side of the menu bar there's an 'X', this will close the current document, but leave Word running. IMHO this is much better than on Macs because it is plainly obvious that the program is still running.
Now some things (*cough*IE) hide instead of quitting, this is annoying true. But whining that programmers should improve the startup times will not help, because that's exactly what they've done: Improve the startup time by keeping parts of the program already running. The *real* solutions are to either get better hardware (which costs you, but not the developers), work more on writing more efficient & smaller code (which costs the developers, who pass it on to you), or just be patient and wait for the huge amount of data to be loaded off the hard drive. So until you can find some miracle of economics that will force the developers to pay for your hardware (and everyone else's), deal with it.
Slashdot Mirror
heyyy, no fair making your own summary come true.
but that's not how it is. The bug is still known, we still know how to exploit it, nothing is obscured. (well, maybe to the general populus, but the "hackers" are the important people here and they aren't gonna be fooled by this)
It's nearly impossible in that it's EXTREMELY hard to exploit now, whereas it was fairly simple before.
Alas, they seem to have rewritten this section and removed that. At least I can't find it in any of the online docs for the Pentium. Hrmph... It used to be part of the "Architectural Overview", section 2.0
;)
It's not really practical to do something like that anyway, at least on that scale, BUT the segment descriptors contain a "present" flag exactly like the page table entries.
Even in the old 1992 docs there's not a lot of detail as to how to do this, but I would imagine it would be almost identical to the way virtual paging is done. When a segment register is loaded with a segment whose descriptore is marked "not present," the OS loads the appropriate data into the linear 32-bit address space and continues, probably pushing out a segment that's not in use and clearing its present flag.
Honestly, I don't see how it would even be possible to do that with full 4gig segments, maybe that's why Intel removed it. For smaller segments, it should be possible, though it would mean a LOT of moving things around. (like virtual memory with REALLY big pages)
Way to go Intel, make me look stupid
This is wrong.
"Microprocessors, Volume I" Intel Corporation, 1992 pg 2-18:
I believe the trick is to mark segment registers as invalid and use some of the free bits in the descriptor to tell the OS where to load it from. When the program tries to access that segment, an exception is generated which allows the OS to swap in the appropriate data. It's much like virtual memory is usually done, but using the segment registers as "super" pages.the physical address is LARGER than 32 bits. It is 36 bits on Wmt.
Oh, ok. 36 bits/64 gigs.
It's just a matter of how statistics work. People dying at a very young age will skew the average a lot more.
If you have 10 people that all live to be 50, the average is 50. To drop the average to 45 you need to kill off about:
age # of people
birth 1
25 2
33 3
37 4
40 5
41 6
42 7
43 8
44 9
45 10
Clearly those dying very young have a much greater impact.
Yes, but you still need to get the packet in question processed in the right part of AIM. Previously, these could be sent normally through the service from another user. Now, you somehow have to slip it into the communication stream, afaik this means using some sort of packet sniffer to find and monitor the connection for a while at least.
This is not security through obscurity, it's taking a trivial exploit and making it nearly impossible. I should hope they're also working on fixing the actual buffer overflow, but for now, and for users who don't upgrade (or don't know how) once this is done, it's much less of a concern.
I just saw Sun E250s being sold for $1750 today that were $15,000 a year and half ago. Not a bad deal for the user, a major disaster for Sun.
Why doesn't Sun just buy them back? They could still make money off the deal, then refusbish them or recycle parts and sell it again, back at full (or slightly reduced) price. Plus, they've already made money in the first place.
With 32-bits, you should be able to access 4gigs of memory, I assume there's something in the system that uses one bit as a flag to limit it to 2 gigs.
If you *really* need more memory, using segment registers (on 386 even) will give you 46 bits, for 64 terabytes (per task btw, not total). But that's not linear, and it's VIRTUAL, not PHYSICAL memory. The hardware address bus is still only 32 bits wide (well, technically a bit less, but only because memory isn't arranged in bytes), so you can still only access 4 gigs of physical ram without EXTREME ugliness.
We got that "who stole all the magic" car commercial or whatever, you shoulda heard the booing!
Its quite fortunate for Apple.
Of course it's good for the hardware vender, they get to sell more stuff, and it's good for the software developers because they don't have to work as hard to support the older hardware.
So is that your point? Fortunately for Apple it requires a better computer, but unfortunately for the users they won't get as much work out of older systems with it? That's fine, but why should we concern ourselves with what's good for Apple?
I got XP Pro(for free) and didn't think I would like or even need it. But after using it for a month now, I can say it has NEVER crashed and is now my only desktop OS.
If the OS still functions perfectly after a year of patches and hardware upgrades, then I will be impressed. 2k has been pretty stable for me, except for problems that slowly seeped in after about 4 months which I've been to busy to try to locate or fix.
That's the unfortunate part about the system getting more stable, it takes longer to know just how stable it is...
OSX requires a bit.. more. Fortunately and unfortunately.
How is an OS that uses more processor power fortunate for the end user? The extra features are definitely a benefit, but I don't see how extra requirements are.
When you can't get the best programmer in each field to design/program each element there's bound to be duplication as new versions are written that behave (either in function or interface) in what is percieved to be a superior way. If evolution works for software then the best code will eventually be borrowed for other projects or just generally used more. In other words, if several different wheels are invented simultaneously across the globe, the optimal wheel is more likely to be found.
Also remember that the software is not the only output of programming. There's also the additional experience and skills gained by the programmer.
It is, in fact "some bizarre magic," so to speak, not because we do not understand it, but because it requires considerable algorithmic search to find such an efficient (quick, small and effective) state through which the machine can produce its effect - its magic in the same sense that a chess playing program is magic.
My point is that the mechanism is understood, but the actual process is not. They know vaguely *what* is hapenning, just not exactly *how*.
The insight that you fail to grasp is that with this technique, we can take advantage of those variables that you say we should eliminate, making designs better.
That's not what I said. What I said is that it is usually eliminated because it's hard to calculate. Nothing about *should*. You seem to have failed to grasp the distiction.
As far as complexity, what kind of bacteria are you thinking of that its so far from?
Any kind? This circuit can detect between two tones. I'd say bacteria can do MUCH more complex things than that.
Old news... IIRC:
1. This will not lead to intelligent machines that will try to make you into toast. This is not even close to the sort of complexity of evolving bacteria.
2. The reason he doesn't understand how it's working is because the design is using the interference generated in one part of the chip someplace else. Conventional designs try to eliminate this because it's so complex to predect. This is not a matter of "some bizarre magic is happenning that we don't understand and it will probably turn us all into pools of gravy."
Legacy Boxes
These don't count for new computers for home users. Typical home users have one computer, and this is it. It's useful for some people (me, for example), but not most.
The sheer waste of burning a 660/700MB CDR to transfer a 1MB or less file. . .and CD-RW doesn't count, not all drives can READ a CD-RW
Now that's a shame... current drives should be able to read CD-RW.
Personally, I usually use ethernet to transfer files, but the many home users don't even have the problem to begin with.
It's largely the trackball (why does everybody hate these?)
Trackballs require fine motion control with the thumb, mice use the whole hand/arm/wrist. Unless you're naturally predisposed for it, trackballs are much harder to use without practice.
but also the total lack of desktop icons and reorganised Windows Start menu
Man, I'd hate to see someone else try to use my computer... I've got a VWM, a command box, and keyboard shortcuts. No icons, no taskbar, no start menu. heh. Gotta love LiteStep. (luckily this is my home computer...)
Stars are huge and far away, but human technology and science can reduce them to pictures for your PC desktop. Who is more powerful than who in this case?
Well, in a star vs scientist fight, I'm still betting on the star. Sure, we can reduce the star to a pretty picture, but the star can reduce us to plasma.
Fine, all the vastness and stuff doesn't impress you, but don't get cocky for it.
It's all modular
I think this is the most important thing. Design your code to be modular so you can rewrite bits without it breaking.
Keep in mind that many game developers simply license the engine and modify it, so they *can't* do this. Now if the people who wrote the engine open-sourced that first, then they could, but that's harder since the engine will make money long after the game has stopped.
Just out of curiosity, do these filtering things look for every possible executable extension? Wouldn't it be better to check if the first two letters are "MZ" to tell if it's executable? (or rather, if they're not MZ then it's not executable)
I can't believe it takes an AC to realize that user interface design != programming. In general, programmers are very bad at UI design because they understand the system too well and the user not at all. (unless they're designing software tools...)
This isn't a "nerds vs cruel world" thing, it's a matter of comunication. The computer needs to communicate with the users. The developer is in charge of how the computer communicates. Nobody is really in charge of how the user communicates. Whoever designs the UI needs to understand some of how the computer works and more of how the user works. Not easy...
Remember when you had to purchase Netscape, but IE was free?
No, I was a student back then. How is this relevant anyway? (Remember when IE TOTALLY SUCKED?) So MS had deeper pockets than Netscape. So what? How much do you have to pay for mozilla?
Mozilla MAY -become- better, but it isn't, yet.
For me it is. For everyone else, who cares?
The bias on /. is VERY old news.
MANY windows programs do this, notably ones with using MDI. MS Word for example, you'll notice on the right side of the menu bar there's an 'X', this will close the current document, but leave Word running. IMHO this is much better than on Macs because it is plainly obvious that the program is still running.
Now some things (*cough*IE) hide instead of quitting, this is annoying true. But whining that programmers should improve the startup times will not help, because that's exactly what they've done: Improve the startup time by keeping parts of the program already running. The *real* solutions are to either get better hardware (which costs you, but not the developers), work more on writing more efficient & smaller code (which costs the developers, who pass it on to you), or just be patient and wait for the huge amount of data to be loaded off the hard drive. So until you can find some miracle of economics that will force the developers to pay for your hardware (and everyone else's), deal with it.
That's little consolation if 700 songs start with 'S' and you want one in the middle.