[bpf-next,0/2] bpf, x64: Introduce two tailcall enhancements

Message

Leon Hwang Oct. 28, 2024, 1:40 p.m. UTC

This patch set introduces two enhancements aimed at improving tailcall
handling in the x64 JIT:

1. Tailcall info is propagated only for subprogs.
2. Tailcall info is propagated through the trampoline only when the target
   is a subprog and it is tail_call_reachable.

v1 -> v2:
  * Address comment from Alexei:
    * Rather live with tail call inefficiency than abuse insns fields
      further.

Leon Hwang (2):
  bpf, x64: Propagate tailcall info only for subprogs
  bpf, verifier: Check trampoline target is tail_call_reachable subprog

 arch/x86/net/bpf_jit_comp.c | 3 ++-
 include/linux/bpf.h         | 1 +
 kernel/bpf/verifier.c       | 4 +++-
 3 files changed, 6 insertions(+), 2 deletions(-)