Re: [RFC PATCH glibc 4/8] glibc: Perform rseq(2) registration at C startup and thread creation (v15)

From: Mathieu Desnoyers
Date: Thu Mar 19 2020 - 11:56:40 EST


----- On Mar 19, 2020, at 10:53 AM, Florian Weimer fw@xxxxxxxxxxxxx wrote:

> * Mathieu Desnoyers via Libc-alpha:
>
>> Changes since v14:
>> - Update copyright range to include 2020.
>> - Introduce __ASSUME_RSEQ defined for --enable-kernel=4.18.0 and higher.
>> - Use ifdef __ASSUME_RSEQ rather than ifdef __NR_rseq to discover rseq
>> availability. This is necessary now that the system call numbers are
>> integrated within glibc.
>
> It's not quite clear to me why you need __ASSUME_RSEQ.

This is how I noticed other Linux features were being integrated,
so I figured this is how I should do it. Monkey see, monkey do. ;-)

> Can you use __has_include in <sys/rseq.h>, with a copy of the kernel
> definitions if the kernel header is not available?

Sure. Should I pull a verbatim copy of uapi linux/rseq.h into glibc ?
If so, where should I put it ?

Thanks,

Mathieu




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