On 9/9/20 11:52 PM, Matthew Wilcox wrote:
> On Wed, Sep 09, 2020 at 10:47:24PM +0100, Chris Down wrote:
>> Vlastimil Babka writes:
>> > - Exit also on other signals such as SIGABRT, SIGTERM? If I write to drop_caches
>> > and think it's too long, I would prefer to kill it by ctrl-c and not just kill
>>
>> Oh dear, fatal_signal_pending() doesn't consider cases with no more
>> userspace instructions due to SIG_DFL on TERM/INT etc, that seems misleading
>> :-( I had (naively) believed it internally checks the same set as
>> TASK_KILLABLE.
>>
>> Chuxin, Muchun, can you please make it work using TASK_KILLABLE in a similar
>> way to how schedule_timeout_killable and friends do it instead, so that
>> other signals will be caught?
>
> You're mistaken.
Ah actually it was me who thought fatal_signal_pending() was only for SIGKILL,
OOM and whatnot. Sorry for the noise.
> if (sig_fatal(p, sig) &&
> !(signal->flags & SIGNAL_GROUP_EXIT) &&
> !sigismember(&t->real_blocked, sig) &&
> (sig == SIGKILL || !p->ptrace)) {
> ...
> sigaddset(&t->pending.signal, SIGKILL);
>
> static inline int __fatal_signal_pending(struct task_struct *p)
> {
> return unlikely(sigismember(&p->pending.signal, SIGKILL));
> }
>
