Re: [RFC 0/3] extend kexec_file_load system call

From: Jeremy Kerr
Date: Thu Jul 21 2016 - 20:54:02 EST


Hi Thiago,

> So even if not ideal, the solution above is desirable for powerpc. We would
> like to preserve the ability of allowing userspace to pass parameters to the
> OS via the DTB, even if secure boot is enabled.
>
> I would like to turn the above into a proposal:
>
> Extend the syscall as shown in this RFC from Takahiro AKASHI, but instead of
> accepting a complete DTB from userspace, the syscall accepts a DTB
> containing only a /chosen node. If the DTB contains any other node, the
> syscall fails with EINVAL. If the DTB contains any subnode in /chosen, or if
> there's a compatible or device_type property in /chosen, the syscall fails
> with EINVAL as well.

This works for me. We could even have it as just a DTB fragment that is
merged *at* the /chosen/ node of the kernel-device tree - so would not
contain a /chosen node itself, and it would be impossible to provide
nodes outside of /chosen. Either is fine.

Thanks!


Jeremy