diff options
Diffstat (limited to 'kernel/bpf/verifier.c')
| -rw-r--r-- | kernel/bpf/verifier.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 8b511a4fe84a..5b3c0a95244f 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5381,9 +5381,16 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx) } new_sl->next = env->explored_states[insn_idx]; env->explored_states[insn_idx] = new_sl; - /* connect new state to parentage chain */ - for (i = 0; i < BPF_REG_FP; i++) - cur_regs(env)[i].parent = &new->frame[new->curframe]->regs[i]; + /* connect new state to parentage chain. Current frame needs all + * registers connected. Only r6 - r9 of the callers are alive (pushed + * to the stack implicitly by JITs) so in callers' frames connect just + * r6 - r9 as an optimization. Callers will have r1 - r5 connected to + * the state of the call instruction (with WRITTEN set), and r0 comes + * from callee with its full parentage chain, anyway. + */ + for (j = 0; j <= cur->curframe; j++) + for (i = j < cur->curframe ? BPF_REG_6 : 0; i < BPF_REG_FP; i++) + cur->frame[j]->regs[i].parent = &new->frame[j]->regs[i]; /* clear write marks in current state: the writes we did are not writes * our child did, so they don't screen off its reads from us. * (There are no read marks in current state, because reads always mark |