diff options
| author | Steven Rostedt <rostedt@goodmis.org> | 2014-03-18 11:27:37 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-05-31 13:20:32 -0700 |
| commit | 70d1e53b3b1f06cdf282e6753ffb11a95d5a6854 (patch) | |
| tree | 3b768af621bc50f074bd1a139cf05907f203be79 /drivers | |
| parent | 6dee738af60144c03cbfd0699bbb99f4ff4e021a (diff) | |
| download | lwn-70d1e53b3b1f06cdf282e6753ffb11a95d5a6854.tar.gz lwn-70d1e53b3b1f06cdf282e6753ffb11a95d5a6854.zip | |
drm/i915: Do not dereference pointers from ring buffer in evict event
commit 9297ebf29ad9118edd6c0fedc84f03e35028827d upstream.
The TP_printk() should never dereference any pointers, because the ring
buffer can be read at some unknown time in the future. If a device no
longer exists, it can cause a kernel oops. This also makes this
event useless when saving the ring buffer in userspaces tools such as
perf and trace-cmd.
The i915_gem_evict_vm dereferences the vm pointer which may also not
exist when the ring buffer is read sometime in the future.
Link: http://lkml.kernel.org/r/1395095198-20034-3-git-send-email-artagnon@gmail.com
Reported-by: Ramkumar Ramachandra <artagnon@gmail.com>
Fixes: bcccff847d1f "drm/i915: trace vm eviction instead of everything"
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
[danvet: Try to make it actually compile]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_trace.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/i915_trace.h b/drivers/gpu/drm/i915/i915_trace.h index 6e580c98dede..783ae08200e8 100644 --- a/drivers/gpu/drm/i915/i915_trace.h +++ b/drivers/gpu/drm/i915/i915_trace.h @@ -238,14 +238,16 @@ TRACE_EVENT(i915_gem_evict_vm, TP_ARGS(vm), TP_STRUCT__entry( + __field(u32, dev) __field(struct i915_address_space *, vm) ), TP_fast_assign( + __entry->dev = vm->dev->primary->index; __entry->vm = vm; ), - TP_printk("dev=%d, vm=%p", __entry->vm->dev->primary->index, __entry->vm) + TP_printk("dev=%d, vm=%p", __entry->dev, __entry->vm) ); TRACE_EVENT(i915_gem_ring_sync_to, |