bpf: Add cond_break macro

Use may_goto instruction to implement cond_break macro.
Ideally the macro should be written as:
  asm volatile goto(".byte 0xe5;
                     .byte 0;
                     .short %l[l_break] ...
                     .long 0;
but LLVM doesn't recognize fixup of 2 byte PC relative yet.
Hence use
  asm volatile goto(".byte 0xe5;
                     .byte 0;
                     .long %l[l_break] ...
                     .short 0;
that produces correct asm on little endian.

Signed-off-by: Alexei Starovoitov <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Acked-by: Eduard Zingerman <[email protected]>
Acked-by: John Fastabend <[email protected]>
Tested-by: John Fastabend <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]

0 files changed, 0 insertions, 0 deletions