On October 6, 2024 12:17:40 PM PDT, Uros Bizjak [off-list ref] wrote:

On Sun, Oct 6, 2024 at 8:01 PM David Laight [off-list ref] wrote:

quoted

...

quoted

Due to the non-negligible impact of PIE, perhaps some kind of
CONFIG_PIE config definition should be introduced, so the assembly
code would be able to choose optimal asm sequence when PIE and non-PIE
is requested?

I wouldn't have thought that performance mattered in the asm code
that runs during startup?

No, not the code that runs only once, where performance impact can be tolerated.

This one:

https://lore.kernel.org/lkml/20240925150059.3955569-44-ardb+git@google.com/ (local)

Uros.

Yeah, running the kernel proper as PIE seems like a lose all around. The decompressor, ELF stub, etc, are of course a different matter entirely (and at least the latter can't rely on the small or kernel memory models anyway.)