Re: Restartable Sequences system call merged into Linux

From: Mathieu Desnoyers
Date: Fri Jun 15 2018 - 13:50:25 EST


----- On Jun 15, 2018, at 1:09 AM, Florian Weimer fweimer@xxxxxxxxxx wrote:

> On 06/14/2018 03:01 PM, Mathieu Desnoyers wrote:
>> Another alternative would be to somehow let glibc handle the registration,
>> perhaps only doing it for applications expressing their interest for rseq.
>
> That's not really possible. We can't rely on the visibility of symbol
> bindings due to lazy binding and hidden visibility. Registration of
> intent by other means will not work because if it is done from user
> code, some other library may have already launched a thread at this point.
>
> (It's also a moot point if we want to use restartable sequences in glibc
> itself.)

Considering that we can expect the glibc memory allocator to benefit from
rseq to speed up its memory allocator, this means pretty much any application
linked against glibc *will* end up using rseq indirectly.

Thanks,

Mathieu

--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com