51a405dea0
[ Upstream commit bc1922e5d349db4be14c55513102c024c2ae8a50 ] The vma destruction code was using an unlocked advisory check for drm_mm_node_allocated() to avoid racing with eviction code unbinding the vma. This is very fragile and prohibits the dereference of non-refcounted pointers of dying vmas after a call to __i915_vma_unbind(). It also prohibits the dereference of vma->obj of refcounted pointers of dying vmas after a call to __i915_vma_unbind(), since even if a refcount is held on the vma, that won't guarantee that its backing object doesn't get destroyed. So introduce an unbind under the vm mutex at object destroy time, removing all weak references of the vma and its object from the object vma list and from the vm bound list. Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220127115622.302970-1-thomas.hellstrom@linux.intel.com 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.