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* [Intel-gfx] [PATCH 1/3] drm/i915/gt: Mark up racy reads for intel_context.inflight
@ 2020-03-10 14:13 Chris Wilson
  2020-03-10 14:13 ` [Intel-gfx] [PATCH 2/3] drm/i915: Mark up racy read of active rq->engine Chris Wilson
                   ` (4 more replies)
  0 siblings, 5 replies; 9+ messages in thread
From: Chris Wilson @ 2020-03-10 14:13 UTC (permalink / raw)
  To: intel-gfx

When being used across multiple real engines inside a virtual engine,
the intel_context.inflight is updated atomically, and so we must
annotate the racy read from outside the owning context.

[11142.482846] BUG: KCSAN: data-race in __execlists_submission_tasklet [i915] / __execlists_submission_tasklet [i915]
[11142.482867]
[11142.482878] write (marked) to 0xffff8881f257b5e0 of 8 bytes by interrupt on cpu 2:
[11142.483107]  __execlists_submission_tasklet+0x1d33/0x2120 [i915]
[11142.483336]  execlists_submission_tasklet+0xd3/0x170 [i915]
[11142.483355]  tasklet_action_common.isra.0+0x42/0xa0
[11142.483371]  __do_softirq+0xd7/0x2cd
[11142.483384]  irq_exit+0xbe/0xe0
[11142.483401]  do_IRQ+0x51/0x100
[11142.483424]  ret_from_intr+0x0/0x1c
[11142.483446]  do_idle+0x133/0x1f0
[11142.483465]  cpu_startup_entry+0x14/0x16
[11142.483483]  start_secondary+0x120/0x180
[11142.483498]  secondary_startup_64+0xa4/0xb0
[11142.483512]
[11142.483528] read to 0xffff8881f257b5e0 of 8 bytes by interrupt on cpu 1:
[11142.483755]  __execlists_submission_tasklet+0x14e/0x2120 [i915]
[11142.483981]  execlists_submission_tasklet+0xd3/0x170 [i915]
[11142.483999]  tasklet_action_common.isra.0+0x42/0xa0
[11142.484014]  __do_softirq+0xd7/0x2cd
[11142.484028]  do_softirq_own_stack+0x2a/0x40
[11142.484046]  do_softirq.part.0+0x26/0x30
[11142.484071]  __local_bh_enable_ip+0x46/0x50
[11142.484299]  i915_gem_do_execbuffer+0x39c1/0x4e50 [i915]
[11142.484528]  i915_gem_execbuffer2_ioctl+0x2c3/0x580 [i915]
[11142.484546]  drm_ioctl_kernel+0xe4/0x120
[11142.484559]  drm_ioctl+0x297/0x4c7
[11142.484572]  ksys_ioctl+0x89/0xb0
[11142.484586]  __x64_sys_ioctl+0x42/0x60
[11142.484610]  do_syscall_64+0x6e/0x2c0
[11142.484627]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/gt/intel_context_types.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h b/drivers/gpu/drm/i915/gt/intel_context_types.h
index 11278343b9b5..0f3b68b95c56 100644
--- a/drivers/gpu/drm/i915/gt/intel_context_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_context_types.h
@@ -45,8 +45,8 @@ struct intel_context {
 
 	struct intel_engine_cs *engine;
 	struct intel_engine_cs *inflight;
-#define intel_context_inflight(ce) ptr_mask_bits((ce)->inflight, 2)
-#define intel_context_inflight_count(ce) ptr_unmask_bits((ce)->inflight, 2)
+#define intel_context_inflight(ce) ptr_mask_bits(READ_ONCE((ce)->inflight), 2)
+#define intel_context_inflight_count(ce) ptr_unmask_bits(READ_ONCE((ce)->inflight), 2)
 
 	struct i915_address_space *vm;
 	struct i915_gem_context __rcu *gem_context;
-- 
2.20.1

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^ permalink raw reply related	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2020-03-11 14:33 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-03-10 14:13 [Intel-gfx] [PATCH 1/3] drm/i915/gt: Mark up racy reads for intel_context.inflight Chris Wilson
2020-03-10 14:13 ` [Intel-gfx] [PATCH 2/3] drm/i915: Mark up racy read of active rq->engine Chris Wilson
2020-03-10 14:24   ` [Intel-gfx] [PATCH v2] " Chris Wilson
2020-03-10 15:29     ` Mika Kuoppala
2020-03-10 14:13 ` [Intel-gfx] [PATCH 3/3] drm/i915/execlists: Mark up data-races in virtual engines Chris Wilson
2020-03-10 15:35   ` Mika Kuoppala
2020-03-10 15:01 ` [Intel-gfx] [PATCH 1/3] drm/i915/gt: Mark up racy reads for intel_context.inflight Mika Kuoppala
2020-03-11  8:40 ` [Intel-gfx] ✓ Fi.CI.BAT: success for series starting with [1/3] drm/i915/gt: Mark up racy reads for intel_context.inflight (rev2) Patchwork
2020-03-11 14:33 ` [Intel-gfx] ✓ Fi.CI.IGT: " Patchwork

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