From 02d182430e6f5cfecb531215c6802472f80d7c97 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Tue, 17 Dec 2019 13:47:29 +0000 Subject: [PATCH] drm/i915/gem: Keep request alive while attaching fences Since commit eaac073f8c2e ("drm/i915: Protect request retirement with timeline->mutex"), the request retirement can happen outside of the struct_mutex serialised only by the timeline->mutex. We drop the timeline->mutex on submitting the request (i915_request_add) so after that point, it is liable to be freed. Make sure our local reference is kept alive until we have finished attaching it to the signalers. (Note that this erodes the argument that i915_request_add should consume the reference, but that is a slightly larger patch!) Fixes: eaac073f8c2e ("drm/i915: Protect request retirement with timeline->mutex") Signed-off-by: Chris Wilson Cc: Matthew Auld Cc: Tvrtko Ursulin Reviewed-by: Matthew Auld Link: https://patchwork.freedesktop.org/patch/msgid/20191217134729.3297818-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c index 81eaf812c9dac..7d07131aa3f7d 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c @@ -2730,6 +2730,7 @@ i915_gem_do_execbuffer(struct drm_device *dev, err = eb_submit(&eb); err_request: add_to_client(eb.request, file); + i915_request_get(eb.request); i915_request_add(eb.request); if (fences) @@ -2745,6 +2746,7 @@ err_request: fput(out_fence->file); } } + i915_request_put(eb.request); err_batch_unpin: if (eb.batch_flags & I915_DISPATCH_SECURE) -- 2.39.5