Re: [RFC PATCH v4 1/5] glibc: Perform rseq(2) registration at nptl init and thread creation

From: Florian Weimer
Date: Thu Nov 22 2018 - 10:12:02 EST


* Mathieu Desnoyers:

> Thoughts ?
>
> /* Unregister rseq TLS from kernel. */
> if (has_rseq && __rseq_unregister_current_thread ())
> abort();
>
> advise_stack_range (pd->stackblock, pd->stackblock_size, (uintptr_t) pd,
> pd->guardsize);
>
> /* If the thread is detached free the TCB. */
> if (IS_DETACHED (pd))
> /* Free the TCB. */
> __free_tcb (pd);

Considering that we proceed to free the TCB, I really hope that all
signals are blocked at this point. (I have not checked this, though.)

Wouldn't this address your concern about access to the rseq area?

Thanks,
Florian