[RFC 5/6] net/bnxt: fix mutexes for multi-process

[Stephen Hemminger <stephen@networkplumber.org>]

The BNXT driver supports secondary processes, as shown by the
explicit check in bnxt_dev_init(). Multiple mutexes are located
in structures allocated in shared memory (dev_private and
rte_zmalloc'd structures) that are accessible by both primary
and secondary processes.

However, the mutexes are initialized without PTHREAD_PROCESS_SHARED
attribute, which means synchronization between processes is
undefined behavior.

POSIX mutexes are by default private to the process creating them.
When a mutex protects data structures in shared memory that are
accessed by multiple processes, pthread_mutexattr_setpshared() must
be called with PTHREAD_PROCESS_SHARED.

This patch adds a helper function and updates all mutex
initializations in the BNXT driver:
  - flow_lock, def_cp_lock, health_check_lock, err_recovery_lock
    in struct bnxt (bnxt_ethdev.c)
  - vfr_start_lock in rep_info (bnxt_ethdev.c)
  - txq_lock in struct bnxt_tx_queue (bnxt_txq.c)
  - bnxt_ulp_mutex in session state (bnxt_ulp.c)
  - flow_db_lock in cfg_data (bnxt_ulp_tf.c, bnxt_ulp_tfc.c)

Bugzilla ID: 662
Fixes: 1cb3d39a48f7 ("net/bnxt: synchronize between flow related functions")
Fixes: 5526c8025d4d ("net/bnxt: fix race between interrupt handler and dev config")
Fixes: b59e4be2b6a7 ("net/bnxt: fix VF representor port add")
Cc: stable@dpdk.org

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 drivers/net/bnxt/bnxt_ethdev.c         | 11 ++++++-----
 drivers/net/bnxt/bnxt_txq.c            |  3 ++-
 drivers/net/bnxt/bnxt_util.c           | 13 +++++++++++++
 drivers/net/bnxt/bnxt_util.h           |  2 ++
 drivers/net/bnxt/tf_ulp/bnxt_ulp.c     |  2 +-
 drivers/net/bnxt/tf_ulp/bnxt_ulp_tf.c  |  2 +-
 drivers/net/bnxt/tf_ulp/bnxt_ulp_tfc.c |  2 +-
 7 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/drivers/net/bnxt/bnxt_ethdev.c b/drivers/net/bnxt/bnxt_ethdev.c
index 3c618c6e82..a954514014 100644
--- a/drivers/net/bnxt/bnxt_ethdev.c
+++ b/drivers/net/bnxt/bnxt_ethdev.c
@@ -5858,10 +5858,10 @@ static int bnxt_get_config(struct bnxt *bp)
 static int
 bnxt_init_locks(struct bnxt *bp)
 {
-	pthread_mutex_init(&bp->flow_lock, NULL);
-	pthread_mutex_init(&bp->def_cp_lock, NULL);
-	pthread_mutex_init(&bp->health_check_lock, NULL);
-	pthread_mutex_init(&bp->err_recovery_lock, NULL);
+	bnxt_init_mutex(&bp->flow_lock);
+	bnxt_init_mutex(&bp->def_cp_lock);
+	bnxt_init_mutex(&bp->health_check_lock);
+	bnxt_init_mutex(&bp->err_recovery_lock);
 
 	return 0;
 }
@@ -6879,7 +6879,8 @@ static int bnxt_init_rep_info(struct bnxt *bp)
 	for (i = 0; i < BNXT_MAX_CFA_CODE; i++)
 		bp->cfa_code_map[i] = BNXT_VF_IDX_INVALID;
 
-	return pthread_mutex_init(&bp->rep_info->vfr_start_lock, NULL);
+	bnxt_init_mutex(&bp->rep_info->vfr_start_lock);
+	return 0;
 }
 
 static int bnxt_rep_port_probe(struct rte_pci_device *pci_dev,
diff --git a/drivers/net/bnxt/bnxt_txq.c b/drivers/net/bnxt/bnxt_txq.c
index 3938ebc709..6deed08ad7 100644
--- a/drivers/net/bnxt/bnxt_txq.c
+++ b/drivers/net/bnxt/bnxt_txq.c
@@ -198,7 +198,8 @@ int bnxt_tx_queue_setup_op(struct rte_eth_dev *eth_dev,
 		goto err;
 	}
 
-	return pthread_mutex_init(&txq->txq_lock, NULL);
+	bnxt_init_mutex(&txq->txq_lock);
+	return 0;
 err:
 	bnxt_tx_queue_release_op(eth_dev, queue_idx);
 	return rc;
diff --git a/drivers/net/bnxt/bnxt_util.c b/drivers/net/bnxt/bnxt_util.c
index aa184496c2..c3f0a03f25 100644
--- a/drivers/net/bnxt/bnxt_util.c
+++ b/drivers/net/bnxt/bnxt_util.c
@@ -3,6 +3,7 @@
  * All rights reserved.
  */
 
+#include <pthread.h>
 #include <inttypes.h>
 #include <rte_ether.h>
 
@@ -37,3 +38,15 @@ uint8_t hweight32(uint32_t word32)
 	res = res + (res >> 8);
 	return (res + (res >> 16)) & 0x000000FF;
 }
+
+/* Initialize mutex so that it can be shared between processes */
+void
+bnxt_init_mutex(pthread_mutex_t *mutex)
+{
+	pthread_mutexattr_t attr;
+
+	pthread_mutexattr_init(&attr);
+	pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_SHARED);
+	pthread_mutex_init(mutex, &attr);
+	pthread_mutexattr_destroy(&attr);
+}
diff --git a/drivers/net/bnxt/bnxt_util.h b/drivers/net/bnxt/bnxt_util.h
index 416a6a2609..e1b45d1bb5 100644
--- a/drivers/net/bnxt/bnxt_util.h
+++ b/drivers/net/bnxt/bnxt_util.h
@@ -16,4 +16,6 @@
 int bnxt_check_zero_bytes(const uint8_t *bytes, int len);
 void bnxt_eth_hw_addr_random(uint8_t *mac_addr);
 uint8_t hweight32(uint32_t word32);
+void bnxt_init_mutex(pthread_mutex_t *mutex);
+
 #endif /* _BNXT_UTIL_H_ */
diff --git a/drivers/net/bnxt/tf_ulp/bnxt_ulp.c b/drivers/net/bnxt/tf_ulp/bnxt_ulp.c
index 0c03ae7a83..c2c93859ff 100644
--- a/drivers/net/bnxt/tf_ulp/bnxt_ulp.c
+++ b/drivers/net/bnxt/tf_ulp/bnxt_ulp.c
@@ -214,7 +214,7 @@ ulp_session_init(struct bnxt *bp,
 			session->pci_info.domain = pci_addr->domain;
 			session->pci_info.bus = pci_addr->bus;
 			memcpy(session->dsn, bp->dsn, sizeof(session->dsn));
-			pthread_mutex_init(&session->bnxt_ulp_mutex, NULL);
+			bnxt_init_mutex(&session->bnxt_ulp_mutex);
 			STAILQ_INSERT_TAIL(&bnxt_ulp_session_list,
 					   session, next);
 		}
diff --git a/drivers/net/bnxt/tf_ulp/bnxt_ulp_tf.c b/drivers/net/bnxt/tf_ulp/bnxt_ulp_tf.c
index 38cb5c8b31..5cb79a03e4 100644
--- a/drivers/net/bnxt/tf_ulp/bnxt_ulp_tf.c
+++ b/drivers/net/bnxt/tf_ulp/bnxt_ulp_tf.c
@@ -1469,7 +1469,7 @@ ulp_tf_init(struct bnxt *bp,
 		goto jump_to_error;
 	}
 
-	pthread_mutex_init(&bp->ulp_ctx->cfg_data->flow_db_lock, NULL);
+	bnxt_init_mutex(&bp->ulp_ctx->cfg_data->flow_db_lock);
 
 	/* Initialize ulp dparms with values devargs passed */
 	rc = ulp_tf_dparms_init(bp, bp->ulp_ctx);
diff --git a/drivers/net/bnxt/tf_ulp/bnxt_ulp_tfc.c b/drivers/net/bnxt/tf_ulp/bnxt_ulp_tfc.c
index ad44ec93ca..0c3d1f7dae 100644
--- a/drivers/net/bnxt/tf_ulp/bnxt_ulp_tfc.c
+++ b/drivers/net/bnxt/tf_ulp/bnxt_ulp_tfc.c
@@ -1038,7 +1038,7 @@ ulp_tfc_init(struct bnxt *bp,
 		goto jump_to_error;
 	}
 
-	pthread_mutex_init(&bp->ulp_ctx->cfg_data->flow_db_lock, NULL);
+	bnxt_init_mutex(&bp->ulp_ctx->cfg_data->flow_db_lock);
 
 	rc = ulp_tfc_dparms_init(bp, bp->ulp_ctx, ulp_dev_id);
 	if (rc) {
-- 
2.51.0