6.13-stable review patch. If anyone has any objections, please let me know.
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From: Krzysztof Karas krzysztof.karas@intel.com
commit e49477f7f78598295551d486ecc7f020d796432e upstream.
spin_lock/unlock() functions used in interrupt contexts could result in a deadlock, as seen in GitLab issue #13399, which occurs when interrupt comes in while holding a lock.
Try to remedy the problem by saving irq state before spin lock acquisition.
v2: add irqs' state save/restore calls to all locks/unlocks in signal_irq_work() execution (Maciej)
v3: use with spin_lock_irqsave() in guc_lrc_desc_unpin() instead of other lock/unlock calls and add Fixes and Cc tags (Tvrtko); change title and commit message
Fixes: 2f2cc53b5fe7 ("drm/i915/guc: Close deregister-context race against CT-loss") Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/13399 Signed-off-by: Krzysztof Karas krzysztof.karas@intel.com Cc: stable@vger.kernel.org # v6.9+ Reviewed-by: Maciej Patelczyk maciej.patelczyk@intel.com Reviewed-by: Andi Shyti andi.shyti@linux.intel.com Signed-off-by: Andi Shyti andi.shyti@linux.intel.com Link: https://patchwork.freedesktop.org/patch/msgid/pusppq5ybyszau2oocboj3mtj5x574... (cherry picked from commit c088387ddd6482b40f21ccf23db1125e8fa4af7e) Signed-off-by: Rodrigo Vivi rodrigo.vivi@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c @@ -3425,10 +3425,10 @@ static inline int guc_lrc_desc_unpin(str */ ret = deregister_context(ce, ce->guc_id.id); if (ret) { - spin_lock(&ce->guc_state.lock); + spin_lock_irqsave(&ce->guc_state.lock, flags); set_context_registered(ce); clr_context_destroyed(ce); - spin_unlock(&ce->guc_state.lock); + spin_unlock_irqrestore(&ce->guc_state.lock, flags); /* * As gt-pm is awake at function entry, intel_wakeref_put_async merely decrements * the wakeref immediately but per function spec usage call this after unlock.