Re: rseq system call incompletely wired up in microblaze

[Michal Simek]

Hi Mathieu,

On 14.10.2018 18:46, Mathieu Desnoyers wrote:
> Hi Michal,
> 
> I notice the following commit went into 4.18:
> 
> commit 54b0a2011dfcd2e3fe2c28062694fbbe3eb377a3
> Author: Michal Simek <michal.simek@xxxxxxxxxx>
> Date:   Thu Jun 14 08:24:39 2018 +0200
> 
>     microblaze: Add new syscalls io_pgetevents and rseq
>     
>     Wire up new syscalls io_pgetevents and rseq.
>     
>     Signed-off-by: Michal Simek <michal.simek@xxxxxxxxxx>
> 
> It adds the rseq system call to the microblaze syscall list, but
> does not add the required hooks in the architecture code, nor does
> it select HAVE_RSEQ. So effectively, even though sys_rseq is reserved
> on microblaze, it currently always returns ENOSYS.
> 
> Is your intent to simply reserve the system call number, or to
> also get rseq to work on microblaze ?

Yes. my indentation is allocate syscall numbers for all these new
syscalls because it takes some time when new syscalls numbers are
propagated to toolchain builds.
I can't see a problem if ENOSYS is returned because it is proper
reaction when syscall is not implemented.

Thanks,
Michal