random: rather than entropy_store abstraction, use global

Originally, the RNG used several pools, so having things abstracted out
over a generic entropy_store object made sense. These days, there's only
one input pool, and then an uneven mix of usage via the abstraction and
usage via &input_pool. Rather than this uneasy mixture, just get rid of
the abstraction entirely and have things always use the global. This
simplifies the code and makes reading it a bit easier.
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

include/trace/events/random.h

@@ -28,80 +28,71 @@ TRACE_EVENT(add_device_randomness,
 );
 
 DECLARE_EVENT_CLASS(random__mix_pool_bytes,
-	TP_PROTO(const char *pool_name, int bytes, unsigned long IP),
+	TP_PROTO(int bytes, unsigned long IP),
 
-	TP_ARGS(pool_name, bytes, IP),
+	TP_ARGS(bytes, IP),
 
 	TP_STRUCT__entry(
-		__field( const char *,	pool_name		)
 		__field(	  int,	bytes			)
 		__field(unsigned long,	IP			)
 	),
 
 	TP_fast_assign(
-		__entry->pool_name	= pool_name;
 		__entry->bytes		= bytes;
 		__entry->IP		= IP;
 	),
 
-	TP_printk("%s pool: bytes %d caller %pS",
-		  __entry->pool_name, __entry->bytes, (void *)__entry->IP)
+	TP_printk("input pool: bytes %d caller %pS",
+		  __entry->bytes, (void *)__entry->IP)
 );
 
 DEFINE_EVENT(random__mix_pool_bytes, mix_pool_bytes,
-	TP_PROTO(const char *pool_name, int bytes, unsigned long IP),
+	TP_PROTO(int bytes, unsigned long IP),
 
-	TP_ARGS(pool_name, bytes, IP)
+	TP_ARGS(bytes, IP)
 );
 
 DEFINE_EVENT(random__mix_pool_bytes, mix_pool_bytes_nolock,
-	TP_PROTO(const char *pool_name, int bytes, unsigned long IP),
+	TP_PROTO(int bytes, unsigned long IP),
 
-	TP_ARGS(pool_name, bytes, IP)
+	TP_ARGS(bytes, IP)
 );
 
 TRACE_EVENT(credit_entropy_bits,
-	TP_PROTO(const char *pool_name, int bits, int entropy_count,
-		 unsigned long IP),
+	TP_PROTO(int bits, int entropy_count, unsigned long IP),
 
-	TP_ARGS(pool_name, bits, entropy_count, IP),
+	TP_ARGS(bits, entropy_count, IP),
 
 	TP_STRUCT__entry(
-		__field( const char *,	pool_name		)
 		__field(	  int,	bits			)
 		__field(	  int,	entropy_count		)
 		__field(unsigned long,	IP			)
 	),
 
 	TP_fast_assign(
-		__entry->pool_name	= pool_name;
 		__entry->bits		= bits;
 		__entry->entropy_count	= entropy_count;
 		__entry->IP		= IP;
 	),
 
-	TP_printk("%s pool: bits %d entropy_count %d caller %pS",
-		  __entry->pool_name, __entry->bits,
-		  __entry->entropy_count, (void *)__entry->IP)
+	TP_printk("input pool: bits %d entropy_count %d caller %pS",
+		  __entry->bits, __entry->entropy_count, (void *)__entry->IP)
 );
 
 TRACE_EVENT(debit_entropy,
-	TP_PROTO(const char *pool_name, int debit_bits),
+	TP_PROTO(int debit_bits),
 
-	TP_ARGS(pool_name, debit_bits),
+	TP_ARGS( debit_bits),
 
 	TP_STRUCT__entry(
-		__field( const char *,	pool_name		)
 		__field(	  int,	debit_bits		)
 	),
 
 	TP_fast_assign(
-		__entry->pool_name	= pool_name;
 		__entry->debit_bits	= debit_bits;
 	),
 
-	TP_printk("%s: debit_bits %d", __entry->pool_name,
-		  __entry->debit_bits)
+	TP_printk("input pool: debit_bits %d", __entry->debit_bits)
 );
 
 TRACE_EVENT(add_input_randomness,
@@ -170,36 +161,31 @@ DEFINE_EVENT(random__get_random_bytes, get_random_bytes_arch,
 );
 
 DECLARE_EVENT_CLASS(random__extract_entropy,
-	TP_PROTO(const char *pool_name, int nbytes, int entropy_count,
-		 unsigned long IP),
+	TP_PROTO(int nbytes, int entropy_count, unsigned long IP),
 
-	TP_ARGS(pool_name, nbytes, entropy_count, IP),
+	TP_ARGS(nbytes, entropy_count, IP),
 
 	TP_STRUCT__entry(
-		__field( const char *,	pool_name		)
 		__field(	  int,	nbytes			)
 		__field(	  int,	entropy_count		)
 		__field(unsigned long,	IP			)
 	),
 
 	TP_fast_assign(
-		__entry->pool_name	= pool_name;
 		__entry->nbytes		= nbytes;
 		__entry->entropy_count	= entropy_count;
 		__entry->IP		= IP;
 	),
 
-	TP_printk("%s pool: nbytes %d entropy_count %d caller %pS",
-		  __entry->pool_name, __entry->nbytes, __entry->entropy_count,
-		  (void *)__entry->IP)
+	TP_printk("input pool: nbytes %d entropy_count %d caller %pS",
+		  __entry->nbytes, __entry->entropy_count, (void *)__entry->IP)
 );
 
 
 DEFINE_EVENT(random__extract_entropy, extract_entropy,
-	TP_PROTO(const char *pool_name, int nbytes, int entropy_count,
-		 unsigned long IP),
+	TP_PROTO(int nbytes, int entropy_count, unsigned long IP),
 
-	TP_ARGS(pool_name, nbytes, entropy_count, IP)
+	TP_ARGS(nbytes, entropy_count, IP)
 );
 
 TRACE_EVENT(urandom_read,