On Thu, Apr 07, 2022 at 12:25:49PM -0700, Kui-Feng Lee wrote:
> - if (!__bpf_prog_enter_sleepable(prog)) {
> + if (!__bpf_prog_enter_sleepable(prog, NULL)) {
> /* recursion detected */
> bpf_prog_put(prog);
> return -EBUSY;
> }
> attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in);
> - __bpf_prog_exit_sleepable(prog, 0 /* bpf_prog_run does runtime stats */);
> + __bpf_prog_exit_sleepable(prog, 0 /* bpf_prog_run does runtime stats */, NULL);
Did you miss my comment from the previous review?
Please replace NULL with actual ctx and remove below checks:
> +
> + if (run_ctx)
> + run_ctx->saved_run_ctx = bpf_set_run_ctx(&run_ctx->run_ctx);
...
> -void notrace __bpf_prog_exit(struct bpf_prog *prog, u64 start)
> +void notrace __bpf_prog_exit(struct bpf_prog *prog, u64 start, struct bpf_tramp_run_ctx *run_ctx)
> __releases(RCU)
> {
> + if (run_ctx)
> + bpf_reset_run_ctx(run_ctx->saved_run_ctx);
> +
...
> -u64 notrace __bpf_prog_enter_sleepable(struct bpf_prog *prog)
> +u64 notrace __bpf_prog_enter_sleepable(struct bpf_prog *prog, struct bpf_tramp_run_ctx *run_ctx)
> {
> rcu_read_lock_trace();
> migrate_disable();
> might_fault();
> +
> + if (run_ctx)
> + run_ctx->saved_run_ctx = bpf_set_run_ctx(&run_ctx->run_ctx);
Such 'if' in critical path should be avoided.
