Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [PATCH 4/5] x86: wire up TIF_NOTIFY_SIGNAL | Date | Fri, 16 Oct 2020 15:07:14 +0200 |
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On Fri, Oct 16 2020 at 12:54, Oleg Nesterov wrote: > On 10/16, Thomas Gleixner wrote: > > But again, I won't argue. And to remind, we do not really need to touch > arch_do_signal() at all. We can just add > > if (test_thread_flag(TIF_NOTIFY_SIGNAL)) > tracehook_notify_signal(); > > if (!task_sigpending(current)) > return 0; > > at the start of get_signal() and avoid the code duplication automatically.
That works as well and is smart, but it's completely non obvious while
if (ti_work & _TIF_NOTIFY_SIGNAL) tracehook_notify_signal();
arch_do_signal_or_restart(ti_work & _TIF_SIGPENDING);
makes it entirely clear to follow the logic and it just operates on cached ti_work.
You can still do this for the non generic entry architectures:
if (!IS_ENABLED(CONFIG_GENERIC_ENTRY) && (test_thread_flag(TIF_NOTIFY_SIGNAL)) tracehook_notify_signal();
to avoid the churn in arch/*.
Thanks,
tglx
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