Commit b233920c authored by Alexei Starovoitov's avatar Alexei Starovoitov Committed by Daniel Borkmann
Browse files

bpf: speed up stacksafe check 



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

Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarEdward Cree <ecree@solarflare.com>
Acked-by: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent eb415c98

kernel/bpf/verifier.c

+3 −1
Original line number Diff line number Diff line
@@ -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;