[PATCH v2] tracing: kmem: convert call_site addresses to user friendly symbols

[George G. Davis]

While attempting to debug slub freelist pointer corruption bugs
caused by a module, I discovered that the kmem call_site addresses are
not at all user friendly for modules unless you manage to save a copy
of kallsyms for the running kernel beforehand.

So convert kmem call_site addresses to user friendly symbols which is
especially helpful for module callers when you don't have a copy of
kallsyms for the running kernel.

Reported-by: kbuild test robot <lkp@xxxxxxxxx>
Signed-off-by: George G. Davis <george_davis@xxxxxxxxxx>
---
Change history:
v1:
- First submission
v2:
- Fix kbuild test robot issues as suggested by
  Steven Rostedt.
---
 include/trace/events/kmem.h | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/include/trace/events/kmem.h b/include/trace/events/kmem.h
index eb57e3037deb..09e1eeb4e44d 100644
--- a/include/trace/events/kmem.h
+++ b/include/trace/events/kmem.h
@@ -35,8 +35,8 @@ DECLARE_EVENT_CLASS(kmem_alloc,
 		__entry->gfp_flags	= gfp_flags;
 	),
 
-	TP_printk("call_site=%lx ptr=%p bytes_req=%zu bytes_alloc=%zu gfp_flags=%s",
-		__entry->call_site,
+	TP_printk("call_site=%pS ptr=%p bytes_req=%zu bytes_alloc=%zu gfp_flags=%s",
+		(void *)__entry->call_site,
 		__entry->ptr,
 		__entry->bytes_req,
 		__entry->bytes_alloc,
@@ -88,8 +88,8 @@ DECLARE_EVENT_CLASS(kmem_alloc_node,
 		__entry->node		= node;
 	),
 
-	TP_printk("call_site=%lx ptr=%p bytes_req=%zu bytes_alloc=%zu gfp_flags=%s node=%d",
-		__entry->call_site,
+	TP_printk("call_site=%pS ptr=%p bytes_req=%zu bytes_alloc=%zu gfp_flags=%s node=%d",
+		(void *)__entry->call_site,
 		__entry->ptr,
 		__entry->bytes_req,
 		__entry->bytes_alloc,
@@ -131,7 +131,8 @@ DECLARE_EVENT_CLASS(kmem_free,
 		__entry->ptr		= ptr;
 	),
 
-	TP_printk("call_site=%lx ptr=%p", __entry->call_site, __entry->ptr)
+	TP_printk("call_site=%pS ptr=%p",
+		(void *)__entry->call_site, __entry->ptr)
 );
 
 DEFINE_EVENT(kmem_free, kfree,
-- 
2.7.4