[PATCH 3/3] random: Add pool name to urandom_read trace point

[Andi Kleen]

From: Andi Kleen <ak@xxxxxxxxxxxxxxx>

Now that we have multiple nonblocking_pools it makes sense to report
the name of the pool in the urandom_read trace point. Extend
the trace point to report the name too.

Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
---
 drivers/char/random.c         |  2 +-
 include/trace/events/random.h | 10 ++++++----
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 21ae44b..00c7be2 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -1590,7 +1590,7 @@ urandom_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos)
 	nbytes = min_t(size_t, nbytes, INT_MAX >> (ENTROPY_SHIFT + 3));
 	ret = extract_entropy_user(pool, buf, nbytes);
 
-	trace_urandom_read(8 * nbytes, ENTROPY_BITS(pool),
+	trace_urandom_read(pool->name, 8 * nbytes, ENTROPY_BITS(pool),
 			   ENTROPY_BITS(pool));
 	return ret;
 }
diff --git a/include/trace/events/random.h b/include/trace/events/random.h
index 4684de3..3b5ab5a 100644
--- a/include/trace/events/random.h
+++ b/include/trace/events/random.h
@@ -288,25 +288,27 @@ TRACE_EVENT(random_read,
 );
 
 TRACE_EVENT(urandom_read,
-	TP_PROTO(int got_bits, int pool_left, int input_left),
+	TP_PROTO(const char *pool, int got_bits, int pool_left, int input_left),
 
-	TP_ARGS(got_bits, pool_left, input_left),
+	TP_ARGS(pool, got_bits, pool_left, input_left),
 
 	TP_STRUCT__entry(
+		__field( const char *,  pool			)
 		__field(	  int,	got_bits		)
 		__field(	  int,	pool_left		)
 		__field(	  int,	input_left		)
 	),
 
 	TP_fast_assign(
+		__entry->pool		= pool;
 		__entry->got_bits	= got_bits;
 		__entry->pool_left	= pool_left;
 		__entry->input_left	= input_left;
 	),
 
 	TP_printk("got_bits %d nonblocking_pool_entropy_left %d "
-		  "input_entropy_left %d", __entry->got_bits,
-		  __entry->pool_left, __entry->input_left)
+		  "input_entropy_left %d from %s", __entry->got_bits,
+		  __entry->pool_left, __entry->input_left, __entry->pool)
 );
 
 #endif /* _TRACE_RANDOM_H */
-- 
2.5.0