bpf: speed up stacksafe check (b233920c) · Commits · 戴 / test

Don't check the same stack liveness condition 8 times. once is enough. Signed-off-by:

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;