| Message ID | 20210108150924.29437-1-chris@chris-wilson.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915/gt: Prevent use of engine->wa_ctx after error | expand |
On Fri, Jan 08, 2021 at 03:09:24PM +0000, Chris Wilson wrote: > 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: 604a8f6f1e33 ("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> > --- > drivers/gpu/drm/i915/gt/intel_lrc.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c > index 4e856947fb13..703d9ecc3f7e 100644 > --- a/drivers/gpu/drm/i915/gt/intel_lrc.c > +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c > @@ -1453,6 +1453,9 @@ static int lrc_setup_wa_ctx(struct intel_engine_cs *engine) > 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); > -- > 2.20.1 >
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c index 4e856947fb13..703d9ecc3f7e 100644 --- a/drivers/gpu/drm/i915/gt/intel_lrc.c +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c @@ -1453,6 +1453,9 @@ static int lrc_setup_wa_ctx(struct intel_engine_cs *engine) 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);
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: 604a8f6f1e33 ("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+ --- drivers/gpu/drm/i915/gt/intel_lrc.c | 3 +++ 1 file changed, 3 insertions(+)