From 86eb0c7da56f9f38307ff8a4d388cd10790e4ee6 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Fri, 24 Apr 2020 20:14:10 +0100
Subject: drm/i915: Drop rq->ring->vma peeking from error capture
Git-commit: 9669a5079995ddbe161243ca3e6cc86ca3ab6500
Patch-mainline: v5.8-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322
We only hold the active spinlock while dumping the error state, and this
does not prevent another thread from retiring the request -- as it is
quite possible that despite us capturing the current state, the GPU has
completed the request. As such, it is dangerous to dereference state
below the request as it may already be freed, and the simplest way to
avoid the danger is not include it in the error state.
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/1788
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Andi Shyti <andi.shyti@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200424191410.27570-1-chris@chris-wilson.co.uk
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/i915/i915_gpu_error.c | 5 ++---
drivers/gpu/drm/i915/i915_gpu_error.h | 1 -
2 files changed, 2 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index 7a240f96a0bd..a976cd67b3b3 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -467,14 +467,14 @@ static void error_print_request(struct drm_i915_error_state_buf *m,
if (!erq->seqno)
return;
- err_printf(m, "%s pid %d, seqno %8x:%08x%s%s, prio %d, start %08x, head %08x, tail %08x\n",
+ err_printf(m, "%s pid %d, seqno %8x:%08x%s%s, prio %d, head %08x, tail %08x\n",
prefix, erq->pid, erq->context, erq->seqno,
test_bit(DMA_FENCE_FLAG_SIGNALED_BIT,
&erq->flags) ? "!" : "",
test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT,
&erq->flags) ? "+" : "",
erq->sched_attr.priority,
- erq->start, erq->head, erq->tail);
+ erq->head, erq->tail);
}
static void error_print_context(struct drm_i915_error_state_buf *m,
@@ -1211,7 +1211,6 @@ static void record_request(const struct i915_request *request,
erq->context = request->fence.context;
erq->seqno = request->fence.seqno;
erq->sched_attr = request->sched.attr;
- erq->start = i915_ggtt_offset(request->ring->vma);
erq->head = request->head;
erq->tail = request->tail;
diff --git a/drivers/gpu/drm/i915/i915_gpu_error.h b/drivers/gpu/drm/i915/i915_gpu_error.h
index 0d1f6c8ff355..fa2d82a6de04 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.h
+++ b/drivers/gpu/drm/i915/i915_gpu_error.h
@@ -50,7 +50,6 @@ struct i915_request_coredump {
pid_t pid;
u32 context;
u32 seqno;
- u32 start;
u32 head;
u32 tail;
struct i915_sched_attr sched_attr;
--
2.28.0