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0db94da5a0
The MMIO_REMAP BO is a special 4K IO page that does not have a ttm_tt
behind it. However, amdgpu_ttm_tt_pde_flags() was treating it like
normal TT/doorbell/preempt memory and unconditionally accessed
ttm->caching. For the MMIO_REMAP BO, ttm is NULL, so this leads to a
NULL pointer dereference when computing PDE flags.
Fix this by checking that ttm is non-NULL before reading ttm->caching.
This prevents the crash for MMIO_REMAP and also makes the code more
defensive if other BOs ever come through without a ttm_tt.
Fixes: fb5a52dbe9 ("drm/amdgpu: Implement TTM handling for MMIO_REMAP placement")
Suggested-by: Jesse Zhang <Jesse.Zhang@amd.com>
Suggested-by: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Reviewed-by: Jesse Zhang <Jesse.Zhang@amd.com>
Tested-by: Jesse Zhang <Jesse.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
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 reStructuredText 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.