random: Make random_source definitions const

We can do so trivially, so make these tables read-only.  No functional
change intended.

Reviewed by:	cem, emaste
MFC after:	2 weeks
Sponsored by:	Stormshield
Sponsored by:	Klara, Inc.
Differential Revision:	https://reviews.freebsd.org/D52003

Author: markjdb

sys/crypto/ccp/ccp.c

@@ -79,7 +79,7 @@ static struct pciid {
 	{ 0x15df1022, "AMD CCP-5a" },
 };
 
-static struct random_source random_ccp = {
+static const struct random_source random_ccp = {
 	.rs_ident = "AMD CCP TRNG",
 	.rs_source = RANDOM_PURE_CCP,
 	.rs_read = random_ccp_read,

sys/dev/psci/smccc_trng.c

@@ -58,7 +58,7 @@ static device_attach_t trng_attach;
 
 static unsigned trng_read(void *, unsigned);
 
-static struct random_source random_trng = {
+static const struct random_source random_trng = {
 	.rs_ident = "Arm SMCCC TRNG",
 	.rs_source = RANDOM_PURE_ARM_TRNG,
 	.rs_read = trng_read,

sys/dev/qcom_rnd/qcom_rnd.c

@@ -63,7 +63,7 @@ static int	qcom_rnd_detach(device_t);
 static int	qcom_rnd_harvest(struct qcom_rnd_softc *, void *, size_t *);
 static unsigned	qcom_rnd_read(void *, unsigned);
 
-static struct random_source random_qcom_rnd = {
+static const struct random_source random_qcom_rnd = {
 	.rs_ident = "Qualcomm Entropy Adapter",
 	.rs_source = RANDOM_PURE_QUALCOMM,
 	.rs_read = qcom_rnd_read,

sys/dev/random/armv8rng.c

@@ -44,7 +44,7 @@
 static u_int random_rndr_read(void *, u_int);
 
 static bool has_rndr;
-static struct random_source random_armv8_rndr = {
+static const struct random_source random_armv8_rndr = {
 	.rs_ident = "Armv8 rndr RNG",
 	.rs_source = RANDOM_PURE_ARMV8,
 	.rs_read = random_rndr_read,

sys/dev/random/darn.c

@@ -56,7 +56,7 @@
 
 static u_int random_darn_read(void *, u_int);
 
-static struct random_source random_darn = {
+static const struct random_source random_darn = {
 	.rs_ident = "PowerISA DARN random number generator",
 	.rs_source = RANDOM_PURE_DARN,
 	.rs_read = random_darn_read

sys/dev/random/ivy.c

@@ -51,7 +51,7 @@
 static bool has_rdrand, has_rdseed;
 static u_int random_ivy_read(void *, u_int);
 
-static struct random_source random_ivy = {
+static const struct random_source random_ivy = {
 	.rs_ident = "Intel Secure Key RNG",
 	.rs_source = RANDOM_PURE_RDRAND,
 	.rs_read = random_ivy_read

sys/dev/random/nehemiah.c

@@ -44,7 +44,7 @@
 
 static u_int random_nehemiah_read(void *, u_int);
 
-static struct random_source random_nehemiah = {
+static const struct random_source random_nehemiah = {
 	.rs_ident = "VIA Nehemiah Padlock RNG",
 	.rs_source = RANDOM_PURE_NEHEMIAH,
 	.rs_read = random_nehemiah_read

sys/dev/random/random_harvestq.c

@@ -110,7 +110,7 @@ __read_frequently u_int hc_source_mask;
 
 struct random_sources {
 	CK_LIST_ENTRY(random_sources)	 rrs_entries;
-	struct random_source		*rrs_source;
+	const struct random_source	*rrs_source;
 };
 
 static CK_LIST_HEAD(sources_head, random_sources) source_list =
@@ -849,7 +849,7 @@ random_harvest_deregister_source(enum random_entropy_source source)
 }
 
 void
-random_source_register(struct random_source *rsource)
+random_source_register(const struct random_source *rsource)
 {
 	struct random_sources *rrs;
 
@@ -868,7 +868,7 @@ random_source_register(struct random_source *rsource)
 }
 
 void
-random_source_deregister(struct random_source *rsource)
+random_source_deregister(const struct random_source *rsource)
 {
 	struct random_sources *rrs = NULL;
 

sys/dev/random/randomdev.h

@@ -103,8 +103,8 @@ struct random_source {
 	random_source_read_t		*rs_read;
 };
 
-void random_source_register(struct random_source *);
-void random_source_deregister(struct random_source *);
+void random_source_register(const struct random_source *);
+void random_source_deregister(const struct random_source *);
 
 #endif /* _KERNEL */
 

sys/dev/virtio/random/virtio_random.c

@@ -77,7 +77,7 @@ static struct virtio_feature_desc vtrnd_feature_desc[] = {
 	{ 0, NULL }
 };
 
-static struct random_source random_vtrnd = {
+static const struct random_source random_vtrnd = {
 	.rs_ident = "VirtIO Entropy Adapter",
 	.rs_source = RANDOM_PURE_VIRTIO,
 	.rs_read = vtrnd_read,