From: jeff.mcgee@intel.com
To: intel-gfx@lists.freedesktop.org
Subject: [PATCH 1/2] drm/i915: Properly lock the engine timeline in debugfs i915_gem_request
Date: Fri, 13 Oct 2017 13:10:32 -0700 [thread overview]
Message-ID: <20171013201033.29092-1-jeff.mcgee@intel.com> (raw)
From: Jeff McGee <jeff.mcgee@intel.com>
We are racing with updates to the timeline. This can cause an inconsistent
snapshot to be dumped, or even worse a NULL pointer dereference.
Signed-off-by: Jeff McGee <jeff.mcgee@intel.com>
---
drivers/gpu/drm/i915/i915_debugfs.c | 27 ++++++++++-----------------
1 file changed, 10 insertions(+), 17 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 0bb6e01121fc..135828fb1904 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -657,33 +657,26 @@ static void print_request(struct seq_file *m,
static int i915_gem_request_info(struct seq_file *m, void *data)
{
struct drm_i915_private *dev_priv = node_to_i915(m->private);
- struct drm_device *dev = &dev_priv->drm;
struct drm_i915_gem_request *req;
struct intel_engine_cs *engine;
enum intel_engine_id id;
- int ret, any;
-
- ret = mutex_lock_interruptible(&dev->struct_mutex);
- if (ret)
- return ret;
+ int any = 0;
- any = 0;
for_each_engine(engine, dev_priv, id) {
- int count;
+ int count = 0;
- count = 0;
+ spin_lock_irq(&engine->timeline->lock);
list_for_each_entry(req, &engine->timeline->requests, link)
count++;
- if (count == 0)
- continue;
-
- seq_printf(m, "%s requests: %d\n", engine->name, count);
- list_for_each_entry(req, &engine->timeline->requests, link)
- print_request(m, req, " ");
- any++;
+ if (count) {
+ seq_printf(m, "%s requests: %d\n", engine->name, count);
+ list_for_each_entry(req, &engine->timeline->requests, link)
+ print_request(m, req, " ");
+ any++;
+ }
+ spin_unlock_irq(&engine->timeline->lock);
}
- mutex_unlock(&dev->struct_mutex);
if (any == 0)
seq_puts(m, "No requests\n");
--
2.14.2
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next reply other threads:[~2017-10-13 20:16 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-13 20:10 jeff.mcgee [this message]
2017-10-13 20:10 ` [PATCH 2/2] drm/i915: Include current seqno in debugfs i915_gem_request jeff.mcgee
2017-10-13 20:22 ` [PATCH 1/2] drm/i915: Properly lock the engine timeline " Chris Wilson
2017-10-13 21:26 ` ✓ Fi.CI.BAT: success for series starting with [1/2] " Patchwork
2017-10-14 8:49 ` ✓ Fi.CI.IGT: " Patchwork
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