Making the stack non-executable means the the computer doesn't allow itself to execute any code that is located in the stack. This means that the hacker can upload his evil program, but he can't trick the computer into running it.
Why this feature hasn't been standard in all OS's since the invention of the MMU, I cannot fathom.
For x86 at least, it's probably because x86 doesn't have a feature to make some pages executable, and some not. (Operon a.k.a. Sledgehammer will have this as a new feature, though).
There once was a master programmer who wrote unstructured programs. A novice programmer, seeking to imitate him, also began to write unstructured programs. When the novice asked the master to evaluate his progress, the master criticized him for writing unstructured programs, saying, ``What is appropriate for the master is not appropriate for the novice. You must understand the Tao before transcending structure.''
My college math prof put it another way- It's OK to say "ain't", if you know better.
Harmless to humans. Yeah, okay. Go ahead and stand near one of these, go for it! Be a gerbil.
OOPS! That's what the US government uses the military for! Couldn't forget about that, could we?
I'd guess that the US gov't actually uses other countries' militaries for this purpose.
We were wondering what would happen if we used a 'daisycutter' as an offensive weapon (instead of clearing terrain) right?
"Additionally, if the two photon are emitted exactly 180 degrees opposite of each other, and both are traveling at velocity c, the transmission of data has a theoretical velocity of twice the speed of light."
This just doesn't fit with current physics. Why? Because those photons travel in a reference frame...it's not called general/special !relativety! for nothing. The photons (and the data) travel at a speed of c...also relative to each other, due to the space-time dilation effect (ie it space-time compresses the faster you travel).
The earlier post wasn't clear on whether this trick would be used to send info from a photon-emitter to a photon-observer a half-galaxy away (this info travels at c, because the photons have to travel the distance), or from the observer to the emitter (also c), or if this trick would let two "observers" send info to each other.
Suppose you're generating photon pairs. Half the photons go toward an observer out "east", and half go toward an observer out "west". Thanks to earlier planning, the eastern observer knows when the photons should get there, and can try to observe them or not. Can the western observer tell whether the eastern observer "observed" the photons, and therefore get some bits of an easterner's message? If so, the speed of this info would be the same as the "strange attraction" connection speed.
In this case, you're generating photons not to send your own message, but to let East talk to West.
"We don't know if he's the original discloser, or if, assuming he did *not* have legitimate access, the original discloser was someone who left a CDROM sitting in the lunch room, instead of maintaining physical control over the information, as required by due dilligence... making them the discloser."
This doesn't hold water. If the info was found within his company, and if he reasonably should have known that the info was protected by his company's NDA, and he made it public anyway, he goofed.
I might find a wallet in the street, but just because I didn't steal it I should expect trouble for posting the credit-card numbers and expiration dates on the web.
1. All addresses being 64-bits.
2. All internal integer registers being 64-bits.
For #1, realize that this is going to greatly increase the data size of many applications. The larger the data size, the higher the chance of cache misses. In general, this is a loss, not a win.
For #2, realize that some integer operations are O(N) where N is the number of bits involved. 64-bit multiplication and division are slower than the same 32-bit operations. Period.
The gain with 64-bit processors is one of address space and nothing more.
You do realize that x86 and x86-64 let you choose the data-size on an instruction-by-instruction basis, don't you? So if you want to have a huge table of 32-bit (or 16-bit or 8-bit) values, you can still do that. Or if you only need 32-bit multiplies and divides, you can still do that too.
The 64-bit extensions are just that- extensions. Hammer can still do everything that Athlon/Pentium can do.
Re:Just to remind people why more bits is good..
on
AMD's 64-bit Plot
·
· Score: 0
That's why there are special instructions (a return to segmented memory access) on P3 and P4 processors, allowing up to 64gb of RAM in 4gb segments to be addressed.
If you're referring to the 32-bit RETF instruction, it's been around since the 386 days. And it still returns to a 32-bit address, because only 4gb of RAM is visible at any one time- the OS has to explicitly change the page-tables to map other physical memory into the 4gb virtual space.
2^32 addressing limits addressable HD space to 2 terabytes.
Refresh my memory, how does the cpu's 32-bit limit on virtual addresses control the addressable HD space? The OS may have created such a dependency, so fix the OS.
2^64 addressing is not the only benefit of the change. FPUs see additional benefit when they have more bits. More bits means more precission; this is very important and desirable, especially when working with numbers that have fractional components.
But hammer doesn't add more precision bits to the x87 or SSE registers. It does, however, add _more_ sse registers. And, of course, the FPU instructions will be able to reference tables in memory that are >4GB long, if such a need arises.
I think hammer will be the greatest thing since diced cheese, but not for all the reasons above.
There is software to stop mass mailings
and You only get spam these days because you want spam or are too dumb to do anything about it...
I use procmail for my mail filter. Even though I don't have to actually _see_ most of it, my bandwidth is still getting wasted.
I'd love to see software that actually stops the mass mailings.
It's absurd that a company can consider a 200 million dollar loss "acceptable" and continue operating (under the same management) with plans for expansion.
This reeks of the ability to undercut the console market.
AMD lost more than 200M last quarter, but plans to continue operating- are they trying to undercut the x86 market?
(yes I know they aren't a monopoly, but microsoft isn't a monopoly in the console market. yet.)
As for the wealthy, according to a CBO report in 1999, the top 5% of US taxpayers pay 50% of all taxes, while the top 1% pay 29%. Hmmm, that doesn't sound like "little or no tax" to me.
It isn't cited, so I have to ask- did that CBO report say whether that top 1% had more than 29% of the total income?
Microsoft shall not retaliate against or threaten against an OEM by altering Microsoft's commercial relations with that OEM, or by witholding newly introduced forms of non-monetary Consideration.
Sounds like they can still raise the OEM's prices (as punishment) when it's time to renew those agreements.
Who cares, as long as they keep "Home Movies" -- it's the funniest and most enjoyable show on television, hands down. Along with the Daily Show, it's one of the last two reasons I keep cable.
Looked at the credits. Saw Jonathan Katz as the voice of Melissa's dad. Jonathan Katz, where have I heard that name before? I just can't place... Oh Dear God.
This is a bad argument. IT DOES COST YOU O RECEIVE FROM THE USPS. Just slightly indirectly. The USPS effectively subsidized junk mail with your 1st class postage. They basically piggyback spam into your normal mail.
I thought bulk (junk) mail was subsidizing 1st class postage. Bulk mailers do a bunch of the work (sorting by zip code, adding zip-code bar-code-strips, etc) themselves, in order to get the lower rates.
>Benchmarks are nice and all, but I'm getting kinda tired about hearing how great a CPU benches for about 6 months before I could even buy one with a sack full of money.
Bring me the sack of money- I'll find the cpu to sell to you.
> If a privately owned search engine wants to get money for prioritized links, more power to them, that's free enterprise, it is their perogative to do business that way!
I agree.
> If users dislike it they will go elsewhere and that search engine will be out of business.
I agree again. But how will users know which or how many links were prioritized for money?
For comparision, I have a Time magazine next to me. On page 83 is a paid advert made to look like an article. How do I know it's an advert? In (really) small print at the top of the page is the word Advertisement. That's it. Was this an unfair restriction on Time magazine's advertising scheme?
Slashdot Mirror
Making the stack non-executable means the the computer doesn't allow itself to execute any code that is located in the stack. This means that the hacker can upload his evil program, but he can't trick the computer into running it.
Why this feature hasn't been standard in all OS's since the invention of the MMU, I cannot fathom.
For x86 at least, it's probably because x86 doesn't have a feature to make some pages executable, and some not. (Operon a.k.a. Sledgehammer will have this as a new feature, though).
There once was a master programmer who wrote unstructured programs. A novice programmer, seeking to imitate him, also began to write unstructured programs. When the novice asked the master to evaluate his progress, the master criticized him for writing unstructured programs, saying, ``What is appropriate for the master is not appropriate for the novice. You must understand the Tao before transcending structure.''
My college math prof put it another way- It's OK to say "ain't", if you know better.
Harmless to humans. Yeah, okay. Go ahead and stand near one of these, go for it! Be a gerbil.
OOPS! That's what the US government uses the military for! Couldn't forget about that, could we?
I'd guess that the US gov't actually uses other countries' militaries for this purpose.
We were wondering what would happen if we used a 'daisycutter' as an offensive weapon (instead of clearing terrain) right?
"Additionally, if the two photon are emitted exactly 180 degrees opposite of each other, and both are traveling at velocity c, the transmission of data has a theoretical velocity of twice the speed of light."
This just doesn't fit with current physics. Why? Because those photons travel in a reference frame...it's not called general/special !relativety! for nothing. The photons (and the data) travel at a speed of c...also relative to each other, due to the space-time dilation effect (ie it space-time compresses the faster you travel).
The earlier post wasn't clear on whether this trick would be used to send info from a photon-emitter to a photon-observer a half-galaxy away (this info travels at c, because the photons have to travel the distance), or from the observer to the emitter (also c), or if this trick would let two "observers" send info to each other.
Suppose you're generating photon pairs. Half the photons go toward an observer out "east", and half go toward an observer out "west". Thanks to earlier planning, the eastern observer knows when the photons should get there, and can try to observe them or not. Can the western observer tell whether the eastern observer "observed" the photons, and therefore get some bits of an easterner's message? If so, the speed of this info would be the same as the "strange attraction" connection speed.
In this case, you're generating photons not to send your own message, but to let East talk to West.
They've got you hoodwinked, don't they?
It's not theft. It's a copyright violation.
No, wait. It's not copyright violation, it's piracy.
Wait again. It's not piracy, it's economic terrorism.
"We don't know if he's the original discloser, or if, assuming he did *not* have legitimate access, the original discloser was someone who left a CDROM sitting in the lunch room, instead of maintaining physical control over the information, as required by due dilligence... making them the discloser."
This doesn't hold water. If the info was found within his company, and if he reasonably should have known that the info was protected by his company's NDA, and he made it public anyway, he goofed.
I might find a wallet in the street, but just because I didn't steal it I should expect trouble for posting the credit-card numbers and expiration dates on the web.
1. All addresses being 64-bits.
2. All internal integer registers being 64-bits.
For #1, realize that this is going to greatly increase the data size of many applications. The larger the data size, the higher the chance of cache misses. In general, this is a loss, not a win.
For #2, realize that some integer operations are O(N) where N is the number of bits involved. 64-bit multiplication and division are slower than the same 32-bit operations. Period.
The gain with 64-bit processors is one of address space and nothing more.
You do realize that x86 and x86-64 let you choose the data-size on an instruction-by-instruction basis, don't you? So if you want to have a huge table of 32-bit (or 16-bit or 8-bit) values, you can still do that. Or if you only need 32-bit multiplies and divides, you can still do that too.
The 64-bit extensions are just that- extensions. Hammer can still do everything that Athlon/Pentium can do.
That's why there are special instructions (a return to segmented memory access) on P3 and P4 processors, allowing up to 64gb of RAM in 4gb segments to be addressed.
If you're referring to the 32-bit RETF instruction, it's been around since the 386 days. And it still returns to a 32-bit address, because only 4gb of RAM is visible at any one time- the OS has to explicitly change the page-tables to map other physical memory into the 4gb virtual space.
2^32 addressing limits addressable HD space to 2 terabytes.
Refresh my memory, how does the cpu's 32-bit limit on virtual addresses control the addressable HD space? The OS may have created such a dependency, so fix the OS.
2^64 addressing is not the only benefit of the change. FPUs see additional benefit when they have more bits. More bits means more precission; this is very important and desirable, especially when working with numbers that have fractional components.
But hammer doesn't add more precision bits to the x87 or SSE registers. It does, however, add _more_ sse registers. And, of course, the FPU instructions will be able to reference tables in memory that are >4GB long, if such a need arises.
I think hammer will be the greatest thing since diced cheese, but not for all the reasons above.
There is software to stop mass mailings
and
You only get spam these days because you want spam or are too dumb to do anything about it...
I use procmail for my mail filter. Even though I don't have to actually _see_ most of it, my bandwidth is still getting wasted.
I'd love to see software that actually stops the mass mailings.
It's absurd that a company can consider a 200 million dollar loss "acceptable" and continue operating (under the same management) with plans for expansion.
This reeks of the ability to undercut the console market.
AMD lost more than 200M last quarter, but plans to continue operating- are they trying to undercut the x86 market?
(yes I know they aren't a monopoly, but microsoft isn't a monopoly in the console market. yet.)
I always thought Slashdot should have a boss button.
And you know what "boss" spelled backwards is.
Double-S, O, B.
As for the wealthy, according to a CBO report in 1999, the top 5% of US taxpayers pay 50% of all taxes, while the top 1% pay 29%. Hmmm, that doesn't sound like "little or no tax" to me.
It isn't cited, so I have to ask- did that CBO report say whether that top 1% had more than 29% of the total income?
Microsoft shall not retaliate against or threaten against an OEM by altering Microsoft's commercial relations with that OEM, or by witholding newly introduced forms of non-monetary Consideration.
Sounds like they can still raise the OEM's prices (as punishment) when it's time to renew those agreements.
Just like before.
Who cares, as long as they keep "Home Movies" -- it's the funniest and most enjoyable show on television, hands down. Along with the Daily Show, it's one of the last two reasons I keep cable.
... Oh Dear God.
Looked at the credits. Saw Jonathan Katz as the voice of Melissa's dad. Jonathan Katz, where have I heard that name before? I just can't place
Seriously, is this the same JonKatz?
First I read this:
If you drive down the street, less than a block, you are in one of the worst neighborhoods in oakland.
Then I kind of skipped to this:
Now before you get the picture of [the] little mothers running around with cookie sheets and kenmoore ovens you have to understand....
And I began to wonder what actually goes down in this neighborhood...
This is a bad argument. IT DOES COST YOU O RECEIVE FROM THE USPS. Just slightly indirectly. The USPS effectively subsidized junk mail with your 1st class postage. They basically piggyback spam into your normal mail.
I thought bulk (junk) mail was subsidizing 1st class postage. Bulk mailers do a bunch of the work (sorting by zip code, adding zip-code bar-code-strips, etc) themselves, in order to get the lower rates.
>Benchmarks are nice and all, but I'm getting kinda tired about hearing how great a CPU benches for about 6 months before I could even buy one with a sack full of money. Bring me the sack of money- I'll find the cpu to sell to you.
> If a privately owned search engine wants to get money for prioritized links, more power to them, that's free enterprise, it is their perogative to do business that way!
I agree.
> If users dislike it they will go elsewhere and that search engine will be out of business.
I agree again. But how will users know which or how many links were prioritized for money?
For comparision, I have a Time magazine next to me. On page 83 is a paid advert made to look like an article. How do I know it's an advert? In (really) small print at the top of the page is the word Advertisement. That's it. Was this an unfair restriction on Time magazine's advertising scheme?