Re: [PATCH] prctl: implement PR_GET_ENDIAN for all architectures

On Wed, Feb 1, 2017 at 3:12 PM, James Bottomley
[off-list ref] wrote:

On Tue, 2017-01-31 at 16:26 -0800, Andrew Morton wrote:

quoted

On Sat, 28 Jan 2017 12:13:10 +0100 Helge Deller [off-list ref]
wrote:

quoted

The prctl(PR_GET_ENDIAN) syscall was added to Kernel 2.6.18, but
implemented for PowerPC only. This trivial patch adds support for
this syscall for all other architectures.

Seems reasonable.  I guess.  Why is this needed?

I don't think it is other than for PPC.  If you're not variable endian
(which is only PPC to date), then you should know a priori what endian
you are from the #defines in userspace.

I find it vaguely odd even on PPC.  Surely you can tell what your
endianness is directly.  (An API to query the endianness of another
task would be useful, though.)