bpf: speed up stacksafe check

Don't check the same stack liveness condition 8 times.
once is enough.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Edward Cree <ecree@solarflare.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Alexei Starovoitov 2018-12-13 11:42:31 -08:00 committed by Daniel Borkmann
parent eb415c9898
commit b233920c97
1 changed files with 3 additions and 1 deletions

View File

@ -5204,9 +5204,11 @@ static bool stacksafe(struct bpf_func_state *old,
for (i = 0; i < old->allocated_stack; i++) {
spi = i / BPF_REG_SIZE;
if (!(old->stack[spi].spilled_ptr.live & REG_LIVE_READ))
if (!(old->stack[spi].spilled_ptr.live & REG_LIVE_READ)) {
i += BPF_REG_SIZE - 1;
/* explored state didn't use this */
continue;
}
if (old->stack[spi].slot_type[i % BPF_REG_SIZE] == STACK_INVALID)
continue;