From: Chris Wilson chris@chris-wilson.co.uk
commit 0e124e19ce52d20b28ee9f1d5cdb22e2106bfd29 upstream.
In the course of discovering and closing many races with context closure and execbuf submission, since commit 61231f6bd056 ("drm/i915/gem: Check that the context wasn't closed during setup") we started checking that the context was not closed by another userspace thread during the execbuf ioctl. In doing so we cancelled the inflight request (by telling it to be skipped), but kept reporting success since we do submit a request, albeit one that doesn't execute. As the error is known before we return from the ioctl, we can report the error we detect immediately, rather than leave it on the fence status. With the immediate propagation of the error, it is easier for userspace to handle.
Fixes: 61231f6bd056 ("drm/i915/gem: Check that the context wasn't closed during setup") Testcase: igt/gem_ctx_exec/basic-close-race Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Cc: stable@vger.kernel.org # v5.7+ Reviewed-by: Tvrtko Ursulin tvrtko.ursulin@intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20201203103432.31526-1-chris@c... (cherry picked from commit ba38b79eaeaeed29d2383f122d5c711ebf5ed3d1) Signed-off-by: Rodrigo Vivi rodrigo.vivi@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c @@ -2613,7 +2613,7 @@ static void retire_requests(struct intel break; }
-static void eb_request_add(struct i915_execbuffer *eb) +static int eb_request_add(struct i915_execbuffer *eb, int err) { struct i915_request *rq = eb->request; struct intel_timeline * const tl = i915_request_timeline(rq); @@ -2634,6 +2634,7 @@ static void eb_request_add(struct i915_e /* Serialise with context_close via the add_to_timeline */ i915_request_set_error_once(rq, -ENOENT); __i915_request_skip(rq); + err = -ENOENT; /* override any transient errors */ }
__i915_request_queue(rq, &attr); @@ -2643,6 +2644,8 @@ static void eb_request_add(struct i915_e retire_requests(tl, prev);
mutex_unlock(&tl->mutex); + + return err; }
static int @@ -2844,7 +2847,7 @@ i915_gem_do_execbuffer(struct drm_device err_request: add_to_client(eb.request, file); i915_request_get(eb.request); - eb_request_add(&eb); + err = eb_request_add(&eb, err);
if (fences) signal_fence_array(&eb, fences);