On Fri, Feb 16, 2024 at 07:12:14PM +0100, Oleg Nesterov wrote: > On 02/16, Christian Brauner wrote: > > > > > SI_USER means that the target can trust the values of si_pid/si_uid > > > in siginfo. > > > > Bah, what an annoying nonsense. I see that this can be used to emulate > > stuff like SI_TIMER and SI_ASYNCIO. But I very much doubt the value of > > e.g., emulating SI_DETHREAD. Maybe I'm missing something very obvious. > > I don't understand... My question was what the purpose of being able to to set si_code to e.g., SI_DETHREAD is and then to send a signal to yourself? Because it looks like that's what rt_{tg}sigqueueinfo() and pidfd_send_signal() allows the caller to do. I'm just trying to understand use-cases for this.