On 10/29/24 15:59, Luck, Tony wrote: >> *IF* we switched things to do text poking in the upper half of the >> address space, we'd probably want to find a completely unused PGD entry. >> I'm not sure off the top of my head if we have a good one for that or >> if it's worth the trouble. > I expect that would be easy on 64-bit (no way the kernel needs all the > PGD entries from 256..511) but hard for 32-bit (where kernel address > space is in critically short supply on any machine with >1GB RAM). Yeah, I was talking about 64-bit only. On 32-bit PAE a PGD maps 1/4 of the address space which is totally unworkable for stealing.
