tools, bpf_asm: Hard error on out of range jumps

Per discussion at [0] this was originally introduced as a warning due
to concerns about breaking existing code, but a hard error probably
makes more sense, especially given that concerns about breakage were
only speculation.

  [0] https://lore.kernel.org/bpf/c964892195a6b91d20a67691448567ef528ffa6d.camel@linux.ibm.com/T/#t

Signed-off-by: Ian Denhardt <ian@zenhack.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/bpf/a6b6c7516f5d559049d669968e953b4a8d7adea3.1614201868.git.ian@zenhack.net
This commit is contained in:
Ian Denhardt 2021-02-23 21:15:31 -05:00 committed by Daniel Borkmann
parent cc0f835309
commit 04883a0799

View File

@ -549,9 +549,11 @@ static uint8_t bpf_encode_jt_jf_offset(int off, int i)
{
int delta = off - i - 1;
if (delta < 0 || delta > 255)
fprintf(stderr, "warning: insn #%d jumps to insn #%d, "
if (delta < 0 || delta > 255) {
fprintf(stderr, "error: insn #%d jumps to insn #%d, "
"which is out of range\n", i, off);
exit(1);
}
return (uint8_t) delta;
}