[Bug 1976248] Re: Revert PPC get_user workaround

** Changed in: zfs-linux (Ubuntu)
Status: Fix Committed => Fix Released

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https://bugs.launchpad.net/bugs/1976248

Title:
Revert PPC get_user workaround

Status in linux package in Ubuntu:
Fix Released
Status in zfs-linux package in Ubuntu:
Fix Released
Status in linux source package in Impish:
Fix Released
Status in zfs-linux source package in Impish:
Won't Fix
Status in linux source package in Jammy:
Fix Released
Status in zfs-linux source package in Jammy:
New
Status in linux source package in Kinetic:
Won't Fix
Status in zfs-linux source package in Kinetic:
Won't Fix

Bug description:
[Impact]

 * A change of kernel symbol license allows to drop a PPC specific
workaround in zfs-dkms to use the regular (better) code paths.

 * See details in:

https://git.launchpad.net/ubuntu/+source/zfs-
linux/tree/debian/patches/4900-ppc-get-user-workaround.patch

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1009242

[Test Plan]

 * linux: apply
https://github.com/torvalds/linux/commit/d9e5c3e9e75162f845880535957b7fd0b4637d23

 * zfs-dkms: revert https://git.launchpad.net/ubuntu/+source/zfs-
linux/tree/debian/patches/4900-ppc-get-user-workaround.patch

 * Build on kernel with zfs module on ppc

 * Ensure that zfs.ko successfully loads and works

 * Test that root on zfs installations work on ppc (however, Ubuntu
currently doesn't provide an installation method to achieve this, so
this bit of verification might be hard to complete)

[Where problems could occur]

* linux: the patch only changes the symbol licensing and the
potential tainteness status of the kernel, without any observable user
or kernel space impacts

 * zfs-dkms: The PPC workaround patch is known to be buggy, and the
new arch-independent codepath may now use optimized codepaths inside
kernel resulting in a different behavior as observed by user-space
(operation successful, EFAULT not returned) matching the behavior of
all other architectures.

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