ad9940e377
[ Upstream commit 11362b1befeadaae4d159a8cddcdaf6b8afe08f9 ] There is a potential race condition between hypervisor page faults and flushing a memslot. It is possible for a page fault to read the memslot before a memslot is updated and then write a PTE to the partition-scoped page tables after kvmppc_radix_flush_memslot has completed. (Note that this race has never been explicitly observed.) To close this race, it is sufficient to increment the MMU sequence number while the kvm->mmu_lock is held. That will cause mmu_notifier_retry() to return true, and the page fault will then return to the guest without inserting a PTE. Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.