[LEDE-DEV] ubus/libubox: SIGTERM/SIGINT signals received during ubus_complete_request() calls are ignored

[Felix Fietkau]

On 2017-02-03 16:41, Alin Năstac wrote:
> On Fri, Feb 3, 2017 at 4:19 PM, Felix Fietkau <nbd at nbd.name> wrote:
>> On 2017-02-03 15:57, Alin Năstac wrote:
>>> Hi Felix,
>>>
>>> The SIGTERM ignore issue I was experiencing before is no longer
>>> reproducible after I apply your patch.
>>>
>>> However, I'm concerned about a possible ignore of SIGTERM signal
>>> received during a ubus_complete_request() call. If ctx->stack_depth is
>>> 0, any such signal received between prev_uloop_initialization and the
>>> reset of ulopp_cancelling to false will be ignored. Is this
>>> "uloop_cancelling = false" really necessary?
>>>
>>> BTW, I think the reset of uloop_status and uloop_cancelled should be
>>> executed before uloop_setup_signals() like so:
>>>         if (!recursive_calls++) {
>>>                uloop_status = 0;
>>>                uloop_cancelled = false;
>>>                uloop_setup_signals(true);
>>>         }
>> I was worried about the corner case of performing a ubus request after
>> uloop_run has already completed.
>> I guess one way this could be addressed is by setting uloop_cancelled =
>> false at the end of uloop_run().
> 
> How about adding this uloop function:
> static int recursive_calls = 0; /* moved from uloop_run() context */
> int uloop_cancelling()
> {
>     return recursive_calls > 0 && uloop_cancelled;
> }
> 
> This function will return true only when uloop_run() is still running,
> so you will no longer need to touch uloop_cancelled state at all. This
> way you could reduce the scope of uloop_cancelled to uloop.c too.
Implemented that in libubox.git and ubus.git. Will push to LEDE master soon.

Thanks,

- Felix