ac69496fe6
Our code analyzer reported a double free bug.
In gen8_preallocate_top_level_pdp, pde and pde->pt.base are allocated
via alloc_pd(vm) with one reference. If pin_pt_dma() failed, pde->pt.base
is freed by i915_gem_object_put() with a reference dropped. Then free_pd
calls free_px() defined in intel_ppgtt.c, which calls i915_gem_object_put()
to put pde->pt.base again.
As pde->pt.base is protected by refcount, so the second put will not free
pde->pt.base actually. But, maybe it is better to remove the first put?
Fixes: 82adf901138cc ("drm/i915/gt: Shrink i915_page_directory's slab bucket")
Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210426124340.4238-1-lyl2019@mail.ustc.edu.cn
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.