bpf: Track upper 32-bit register halves' liveness in compute_live_registers()

Extend compute_live_registers() to track upper and lower register
halves' liveness separately. This is mostly straightforward:

- use/def masks are extended to track 2 bits per register;
- compute_insn_live_regs() is updated to properly track these
  2 bits according to the instruction semantics.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20260807-static-zext-v4-4-b6c270013c77@gmail.com
This commit is contained in:
Eduard Zingerman 2026-08-07 13:59:33 -07:00 • committed by Daniel Borkmann
commit ef1ddbfcfa
2 changed files with 59 additions and 31 deletions