Re: [XEN PATCH v1] libxl: use getrandom() syscall for random data extraction

[Julien Grall <julien@xxxxxxx>]

Hi,

On 26/05/2021 10:31, Sergiy Kibrik wrote:
> Hi Julien,
>
> >   From the man:
> >
> > VERSIONS
> >          getrandom() was introduced in version 3.17 of the Linux kernel.
> >    Support was added to glibc in version 2.25.
> >
> > If I am not mistaken glibc 2.25 was released in 2017. Also, the call was only
> > introduced in FreeBSD 12.
> >
> > So I think we want to check if getrandom() can be used. We may also want to
> > consider to fallback to read /dev/urandom if the call return ENOSYS.
> You mean its availability should be checked both at build and runtime?
Correct. You can have a libc suporting getrandom() but a kernel that 
doesn't provide the syscall.
Cheers,

--
Julien Grall