On Wed, Nov 28, 2018 at 02:56:32PM +0000, David Woodhouse wrote:
On Wed, 2018-08-22 at 09:19 +0200, gregkh@linuxfoundation.org wrote:
This is a note to let you know that I've just added the patch titled
x86/entry/64: Remove %ebx handling from error_entry/exitto the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: x86-entry-64-remove-ebx-handling-from-error_entry-exit.patch and it can be found in the queue-4.9 subdirectory.
Can we have it for 4.4 too, please?
[ Note to stable maintainers: this should probably get applied to all kernels. If you're nervous about that, a more conservative fix to add xorl %ebx,%ebx; incl %ebx before the jump to error_exit should also fix the problem. ]
Can we assume it's always from kernel? The Xen code definitely seems to handle invoking this from both kernel and userspace contexts.
Shouldn't %ebx get set to !(regs->rsp & 3) ?
Either way, let's just do it in the stable tree exactly the same way it's done upstream.
- On entry, EBX is a "return to kernel mode" flag:
Re-introduce the typo 'EBS' here, to make the patch apply cleanly to 4.4. It's only removing that line anyway.
Or just cherry-pick upstream commit 75ca5b22260ef7 first.
Queued for 4.4. I've just grabbed the extra spellcheck fix as well.
-- Thanks, Sasha