9be8dc35bc
commit 7f43ef9f0d98abbc0eb5e697628ec06756bf60a9 upstream. Fixes the BUG_ON spuriously triggering under the following circumstances: * reservation_object_reserve_shared is called with shared_count == shared_max - 1, so obj->staged is freed in preparation of an in-place update. * reservation_object_add_shared_fence is called with the first fence, after which shared_count == shared_max. * reservation_object_add_shared_fence is called with a follow-up fence from the same context. In the second reservation_object_add_shared_fence call, the BUG_ON triggers. However, nothing bad would happen in reservation_object_add_shared_inplace, since both fences are from the same context, so they only occupy a single slot. Prevent this by moving the BUG_ON to where an overflow would actually happen (e.g. if a buggy caller didn't call reservation_object_reserve_shared before). v2: * Fix description of breaking scenario (Christian König) * Add bugzilla reference Cc: stable@vger.kernel.org Bugzilla: https://bugs.freedesktop.org/106418 Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> # v1 Reviewed-by: Christian König <christian.koenig@amd.com> # v1 Signed-off-by: Michel Dänzer <michel.daenzer@amd.com> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> Link: https://patchwork.freedesktop.org/patch/msgid/20180704151405.10357-1-michel@daenzer.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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.
See Documentation/00-INDEX for a list of what is contained in each file.
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.