Re: [PATCH 2/2] vfs: support statx(..., NULL, AT_EMPTY_PATH, ...)

[Xi Ruoyao <xry111@xry111.site>]

On Thu, 2024-07-04 at 10:38 +0800, Huacai Chen wrote:
> > So if a LoongArch Glibc is built with Linux kernel headers >= 6.11,
> > it'll use fstatat **even configured --with-kernel=5.19** and fail to run
> > on Linux kernel <= 6.10.  This will immediately blow up building Linux
> > From Scratch on a host distro with an "old" kernel.
> The patch which adds newstat back will CC the stable list and be
> backported to old kernels.

AFAIK in Glibc --enable-kernel=x.y (not with, I was too sleepy
yesterday) means it'll work with even x.y.0.  And even if we "re-
purpose" x.y to mean "the latest x.y patch release" people can still
explicitly spell the patch level, like --enable-kernel=5.19.0.

Thus we still need to handle this in Glibc.

And the backport will raise another question: assume 6.6.40 gets the
backport, what should we do with --enable-kernel=6.6.40?  Maybe we
should we assume newfstatat is available but then people will start to
complain "hey 6.9.7 > 6.6.40 but my Glibc configured with --enable-
kernel=6.6.40 does not work on 6.9.7"...

To me the only rational way seems only assuming 6.11 or later has
newfstatat on LoongArch.

-- 
Xi Ruoyao <xry111@xry111.site>
School of Aerospace Science and Technology, Xidian University