From 3f8cafa4131f67d47c8de326c7dcd561cc65fb38 Mon Sep 17 00:00:00 2001 From: Jiong Wang Date: Fri, 12 Apr 2019 22:59:35 +0100 Subject: bpf: refactor propagate_liveness to eliminate code redundance Access to reg states were not factored out, the consequence is long code for dereferencing them which made the indentation not good for reading. This patch factor out these code so the core code in the loop could be easier to follow. Reviewed-by: Jakub Kicinski Signed-off-by: Jiong Wang Signed-off-by: Alexei Starovoitov --- kernel/bpf/verifier.c | 34 ++++++++++++++++++++-------------- 1 file changed, 20 insertions(+), 14 deletions(-) (limited to 'kernel/bpf') diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index da285df492fd..6fd36a8ba1a0 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -6232,8 +6232,9 @@ static int propagate_liveness(struct bpf_verifier_env *env, const struct bpf_verifier_state *vstate, struct bpf_verifier_state *vparent) { - int i, frame, err = 0; + struct bpf_reg_state *state_reg, *parent_reg; struct bpf_func_state *state, *parent; + int i, frame, err = 0; if (vparent->curframe != vstate->curframe) { WARN(1, "propagate_live: parent frame %d current frame %d\n", @@ -6243,28 +6244,33 @@ static int propagate_liveness(struct bpf_verifier_env *env, /* Propagate read liveness of registers... */ BUILD_BUG_ON(BPF_REG_FP + 1 != MAX_BPF_REG); for (frame = 0; frame <= vstate->curframe; frame++) { + parent = vparent->frame[frame]; + state = vstate->frame[frame]; + parent_reg = parent->regs; + state_reg = state->regs; /* We don't need to worry about FP liveness, it's read-only */ for (i = frame < vstate->curframe ? BPF_REG_6 : 0; i < BPF_REG_FP; i++) { - if (vparent->frame[frame]->regs[i].live & REG_LIVE_READ) + if (parent_reg[i].live & REG_LIVE_READ) continue; - if (vstate->frame[frame]->regs[i].live & REG_LIVE_READ) { - err = mark_reg_read(env, &vstate->frame[frame]->regs[i], - &vparent->frame[frame]->regs[i]); - if (err) - return err; - } + if (!(state_reg[i].live & REG_LIVE_READ)) + continue; + err = mark_reg_read(env, &state_reg[i], &parent_reg[i]); + if (err) + return err; } /* Propagate stack slots. */ - state = vstate->frame[frame]; - parent = vparent->frame[frame]; for (i = 0; i < state->allocated_stack / BPF_REG_SIZE && i < parent->allocated_stack / BPF_REG_SIZE; i++) { - if (parent->stack[i].spilled_ptr.live & REG_LIVE_READ) + parent_reg = &parent->stack[i].spilled_ptr; + state_reg = &state->stack[i].spilled_ptr; + if (parent_reg->live & REG_LIVE_READ) continue; - if (state->stack[i].spilled_ptr.live & REG_LIVE_READ) - mark_reg_read(env, &state->stack[i].spilled_ptr, - &parent->stack[i].spilled_ptr); + if (!(state_reg->live & REG_LIVE_READ)) + continue; + err = mark_reg_read(env, state_reg, parent_reg); + if (err) + return err; } } return err; -- cgit v1.2.3