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drm/i915/gt: Prevent use of engine->wa_ctx after error

On error we unpin and free the wa_ctx.vma, but do not clear any of the
derived flags. During lrc_init, we look at the flags and attempt to
dereference the wa_ctx.vma if they are set. To protect the error path
where we try to limp along without the wa_ctx, make sure we clear those
flags!

Reported-by: Matt Roper <matthew.d.roper@intel.com>
Fixes: 604a8f6f1e ("drm/i915/lrc: Only enable per-context and per-bb buffers if set")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: <stable@vger.kernel.org> # v4.15+
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210108204026.20682-1-chris@chris-wilson.co.uk
master
Chris Wilson 2021-01-08 20:40:20 +00:00
parent 4386b8e5ad
commit 5b4dc95cf7
1 changed files with 3 additions and 0 deletions

View File

@ -1453,6 +1453,9 @@ err:
void lrc_fini_wa_ctx(struct intel_engine_cs *engine)
{
i915_vma_unpin_and_release(&engine->wa_ctx.vma, 0);
/* Called on error unwind, clear all flags to prevent further use */
memset(&engine->wa_ctx, 0, sizeof(engine->wa_ctx));
}
typedef u32 *(*wa_bb_func_t)(struct intel_engine_cs *engine, u32 *batch);