Re: io_uring: process task work in io_uring_register()

From: Jann Horn
Date: Thu Oct 08 2020 - 15:13:47 EST


On Thu, Oct 8, 2020 at 8:24 PM Colin Ian King <colin.king@xxxxxxxxxxxxx> wrote:
> Static analysis with Coverity has detected a "dead-code" issue with the
> following commit:
>
> commit af9c1a44f8dee7a958e07977f24ba40e3c770987
> Author: Jens Axboe <axboe@xxxxxxxxx>
> Date: Thu Sep 24 13:32:18 2020 -0600
>
> io_uring: process task work in io_uring_register()
>
> The analysis is as follows:
>
> 9513 do {
> 9514 ret =
> wait_for_completion_interruptible(&ctx->ref_comp);
>
> cond_const: Condition ret, taking false branch. Now the value of ret is
> equal to 0.

Does this mean Coverity is claiming that
wait_for_completion_interruptible() can't return non-zero values? If
so, can you figure out why Coverity thinks that? If that was true,
it'd sound like a core kernel bug, rather than a uring issue...