linux

This trades verification complexity for runtime overheads due to the
nospec inserted because of the EINVAL.

With increased limits this allows applying mitigations to large BPF
progs such as the Parca Continuous Profiler's prog. However, this
requires a jump-seq limit of 256k. In any case, the same principle
should apply to smaller programs therefore include it even if the limit
stays at 8k for now. Most programs in "VeriFence: Lightweight and
Precise Spectre Defenses for Untrusted Linux Kernel
Extensions" (https://arxiv.org/pdf/2405.00078

) only require a limit of
32k.

Signed-off-by: Luis Gerhorst <luis.gerhorst@fau.de>
Acked-by: Henriette Herzog <henriette.herzog@rub.de>
Cc: Maximilian Ott <ott@cs.fau.de>
Cc: Milan Stephan <milan.stephan@fau.de>