[PATCH v3 2/5] random: defer seeding to EAL init

[David Marchand]

The RNG is documented as being seeded as part of EAL init.

Move the initialisation (seeding) helper out of a constructor and
call it explicitly from rte_eal_init() as it was done before commit
3f002f069612 ("eal: replace libc-based random generation with LFSR").

This also moves the unconditional lcore variable allocation out of a
constructor.

While at it, mark local symbol rand_state as static.

Fixes: 29c39cd3d54d ("random: keep PRNG state in lcore variable")
Cc: stable at dpdk.org

Signed-off-by: David Marchand <david.marchand at redhat.com>
Reviewed-by: Mattias Rönnblom <mattias.ronnblom at ericsson.com>
Acked-by: Anatoly Burakov <anatoly.burakov at intel.com>
Acked-by: Frode Nordahl <frode.nordahl at canonical.com>
---
Changes since v2:
- added assert in rte_s?rand(),

Changes since v1:
- updated commitlog,

---
 lib/eal/common/eal_private.h |  6 ++++++
 lib/eal/common/rte_random.c  | 12 +++++++++---
 lib/eal/freebsd/eal.c        |  2 ++
 lib/eal/linux/eal.c          |  2 ++
 lib/eal/windows/eal.c        |  2 ++
 5 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/lib/eal/common/eal_private.h b/lib/eal/common/eal_private.h
index b2a80dbec8..04ba8ddb86 100644
--- a/lib/eal/common/eal_private.h
+++ b/lib/eal/common/eal_private.h
@@ -702,6 +702,12 @@ eal_get_internal_configuration(void);
 rte_usage_hook_t
 eal_get_application_usage_hook(void);
 
+/**
+ * Initialise random subsystem.
+ */
+void
+eal_rand_init(void);
+
 /**
  * Instruct primary process that a secondary process wants to attach.
  */
diff --git a/lib/eal/common/rte_random.c b/lib/eal/common/rte_random.c
index cf0756f26a..8e62578176 100644
--- a/lib/eal/common/rte_random.c
+++ b/lib/eal/common/rte_random.c
@@ -14,6 +14,8 @@
 #include <rte_lcore_var.h>
 #include <rte_random.h>
 
+#include "eal_private.h"
+
 struct __rte_cache_aligned rte_rand_state {
 	uint64_t z1;
 	uint64_t z2;
@@ -22,7 +24,7 @@ struct __rte_cache_aligned rte_rand_state {
 	uint64_t z5;
 };
 
-RTE_LCORE_VAR_HANDLE(struct rte_rand_state, rand_state);
+static RTE_LCORE_VAR_HANDLE(struct rte_rand_state, rand_state);
 
 /* instance to be shared by all unregistered non-EAL threads */
 static struct rte_rand_state unregistered_rand_state;
@@ -129,8 +131,11 @@ struct rte_rand_state *__rte_rand_get_state(void)
 
 	idx = rte_lcore_id();
 
-	if (unlikely(idx == LCORE_ID_ANY))
+	if (unlikely(idx == LCORE_ID_ANY)) {
+		/* Make sure rte_*rand() was called after rte_eal_init(). */
+		RTE_ASSERT(rand_state != NULL);
 		return &unregistered_rand_state;
+	}
 
 	return RTE_LCORE_VAR(rand_state);
 }
@@ -228,7 +233,8 @@ __rte_random_initial_seed(void)
 	return rte_get_tsc_cycles();
 }
 
-RTE_INIT(rte_rand_init)
+void
+eal_rand_init(void)
 {
 	uint64_t seed;
 
diff --git a/lib/eal/freebsd/eal.c b/lib/eal/freebsd/eal.c
index a96bbf5836..d07cff8651 100644
--- a/lib/eal/freebsd/eal.c
+++ b/lib/eal/freebsd/eal.c
@@ -777,6 +777,8 @@ rte_eal_init(int argc, char **argv)
 		return -1;
 	}
 
+	eal_rand_init();
+
 	eal_check_mem_on_local_socket();
 
 	if (rte_thread_set_affinity_by_id(rte_thread_self(),
diff --git a/lib/eal/linux/eal.c b/lib/eal/linux/eal.c
index a6220524a4..b1e63e37fc 100644
--- a/lib/eal/linux/eal.c
+++ b/lib/eal/linux/eal.c
@@ -1173,6 +1173,8 @@ rte_eal_init(int argc, char **argv)
 		return -1;
 	}
 
+	eal_rand_init();
+
 	eal_check_mem_on_local_socket();
 
 	if (rte_thread_set_affinity_by_id(rte_thread_self(),
diff --git a/lib/eal/windows/eal.c b/lib/eal/windows/eal.c
index 5cdc053a02..5c7526f922 100644
--- a/lib/eal/windows/eal.c
+++ b/lib/eal/windows/eal.c
@@ -410,6 +410,8 @@ rte_eal_init(int argc, char **argv)
 		return -1;
 	}
 
+	eal_rand_init();
+
 	if (rte_thread_set_affinity_by_id(rte_thread_self(),
 			&lcore_config[config->main_lcore].cpuset) != 0) {
 		rte_eal_init_alert("Cannot set affinity");
-- 
2.48.1