On 10/8/20 12:23 PM, Colin Ian King wrote:
> Hi,
>
> 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.
>
> 9515 if (!ret)
> 9516 break;
> 9517 if (io_run_task_work_sig() > 0)
> 9518 continue;
> 9519 } while (1);
> 9520
> 9521 mutex_lock(&ctx->uring_lock);
> 9522
>
> const: At condition ret, the value of ret must be equal to 0.
> dead_error_condition: The condition ret cannot be true.
Thanks, yeah that condition is reversed, should be:
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 4df5b14c2e56..80a0aa33db49 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -9511,8 +9511,8 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode,
ret = wait_for_completion_interruptible(&ctx->ref_comp);
if (!ret)
break;
- if (io_run_task_work_sig() > 0)
- continue;
+ if (io_run_task_work_sig() <= 0)
+ break;
} while (1);
mutex_lock(&ctx->uring_lock);
--
Jens Axboe
