On 10/29/24 16:03, Dave Hansen wrote:
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.
But it is also not necessary.
-hpa
