On Tue, 18 Mar 2014 11:27:37 -0400 Steven Rostedt <rostedt@xxxxxxxxxxx> wrote: > 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@xxxxxxxxx > Reported-by: Ramkumar Ramachandra <artagnon@xxxxxxxxx> Cc: > stable@xxxxxxxxxxxxxxx # 3.13+ Bah, claw's mail is playing havoc with my line wraps. Please fix the above when applying, or I can send anothe patch. Thanks :-) I had to re-insert the patch due to it but didn't see the screw up with the Cc of stable. -- Steve > Fixes: bcccff847d1f "drm/i915: trace vm eviction instead of everything" > Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx> > --- > diff --git a/drivers/gpu/drm/i915/i915_trace.h b/drivers/gpu/drm/i915/i915_trace.h > index 6e580c9..f3e8a90 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 = 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, -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html