Looking for computer arch. phrase....

[Gibson486]

that describes whether something is restricted to read only. Basically, if the beginning bit is 1, it has read or write access. if the beginning bit iz zero, it has read only access. I thought it was dirty bit, but that does not seem to be the case......

edit: it's a way to prevent stack smashing....

 

[CTho9305]

Stack smashing? You don't prevent stack smashing by changing read/write access, you change it by restricting execute access. "Executable / Non-executable bit"?

 

[Gibson486]

Originally posted by: CTho9305
Stack smashing? You don't prevent stack smashing by changing read/write access, you change it by restricting execute access. "Executable / Non-executable bit"?

that's probably it....but what is it called?

 

[CTho9305]

Which part? It's often called an "NX bit" for non-executable. OpenBSD does something related that they call "W^X" for "write xor execute". I'm sure there are many marketing-speak terms for it too though.

 

[Gibson486]

Hmmm.....what does AMD call it? I know that AMD did this when they were claiming that their porcesser had antivirus protection. Is it even the same concept?

 

[nd]

http://en.wikipedia.org/wiki/NX_bit

Looks like AMD just calls it the NX bit to me.

Edit: Found one reference to it being called "Execution Protection" by AMD.