Commit 91f36237 authored by Bernard Metzler's avatar Bernard Metzler Committed by Leon Romanovsky
Browse files

RDMA/siw: Fix tx thread initialization. 



Immediately removing the siw module after insertion may
crash in siw_stop_tx_thread(), if the according thread did
not yet had a chance to initialize its wait queue and
siw_stop_tx_thread() tries to wakeup that thread. Initializing
the threads state before spwaning it fixes it.

Reported-by: default avatarGuoqing Jiang <guoqing.jiang@linux.dev>
Signed-off-by: default avatarBernard Metzler <bmt@zurich.ibm.com>
Link: https://lore.kernel.org/r/20230728114418.124328-1-bmt@zurich.ibm.com


Tested-by: default avatarGuoqing Jiang <guoqing.jiang@linux.dev>
Signed-off-by: default avatarLeon Romanovsky <leon@kernel.org>
parent a45e5f18

drivers/infiniband/sw/siw/siw.h

+2 −1
Original line number Diff line number Diff line
@@ -531,11 +531,12 @@ void siw_qp_llp_data_ready(struct sock *sk); 
void siw_qp_llp_write_space(struct sock *sk);



/* QP TX path functions */

int siw_create_tx_threads(void);

void siw_stop_tx_threads(void);

int siw_run_sq(void *arg);

int siw_qp_sq_process(struct siw_qp *qp);

int siw_sq_start(struct siw_qp *qp);

int siw_activate_tx(struct siw_qp *qp);

void siw_stop_tx_thread(int nr_cpu);

int siw_get_tx_cpu(struct siw_device *sdev);

void siw_put_tx_cpu(int cpu);

drivers/infiniband/sw/siw/siw_main.c

+3 −37
Original line number Diff line number Diff line
@@ -87,29 +87,6 @@ static void siw_device_cleanup(struct ib_device *base_dev) 
	xa_destroy(&sdev->mem_xa);

}



static int siw_create_tx_threads(void)

{

	int cpu, assigned = 0;



	for_each_online_cpu(cpu) {

		/* Skip HT cores */

		if (cpu % cpumask_weight(topology_sibling_cpumask(cpu)))

			continue;



		siw_tx_thread[cpu] =

			kthread_run_on_cpu(siw_run_sq,

					   (unsigned long *)(long)cpu,

					   cpu, "siw_tx/%u");

		if (IS_ERR(siw_tx_thread[cpu])) {

			siw_tx_thread[cpu] = NULL;

			continue;

		}



		assigned++;

	}

	return assigned;

}



static int siw_dev_qualified(struct net_device *netdev)

{

	/*
@@ -529,7 +506,6 @@ static struct rdma_link_ops siw_link_ops = { 
static __init int siw_init_module(void)

{

	int rv;

	int nr_cpu;



	if (SENDPAGE_THRESH < SIW_MAX_INLINE) {

		pr_info("siw: sendpage threshold too small: %u\n",
@@ -574,12 +550,8 @@ static __init int siw_init_module(void) 
	return 0;



out_error:

	for (nr_cpu = 0; nr_cpu < nr_cpu_ids; nr_cpu++) {

		if (siw_tx_thread[nr_cpu]) {

			siw_stop_tx_thread(nr_cpu);

			siw_tx_thread[nr_cpu] = NULL;

		}

	}

	siw_stop_tx_threads();



	if (siw_crypto_shash)

		crypto_free_shash(siw_crypto_shash);
@@ -593,14 +565,8 @@ static __init int siw_init_module(void) 


static void __exit siw_exit_module(void)

{

	int cpu;

	siw_stop_tx_threads();



	for_each_possible_cpu(cpu) {

		if (siw_tx_thread[cpu]) {

			siw_stop_tx_thread(cpu);

			siw_tx_thread[cpu] = NULL;

		}

	}

	unregister_netdevice_notifier(&siw_netdev_nb);

	rdma_link_unregister(&siw_link_ops);

	ib_unregister_driver(RDMA_DRIVER_SIW);

drivers/infiniband/sw/siw/siw_qp_tx.c

+38 −6
Original line number Diff line number Diff line
@@ -1208,10 +1208,45 @@ struct tx_task_t { 


static DEFINE_PER_CPU(struct tx_task_t, siw_tx_task_g);



void siw_stop_tx_thread(int nr_cpu)

int siw_create_tx_threads(void)

{

	kthread_stop(siw_tx_thread[nr_cpu]);

	wake_up(&per_cpu(siw_tx_task_g, nr_cpu).waiting);

	int cpu, assigned = 0;



	for_each_online_cpu(cpu) {

		struct tx_task_t *tx_task;



		/* Skip HT cores */

		if (cpu % cpumask_weight(topology_sibling_cpumask(cpu)))

			continue;



		tx_task = &per_cpu(siw_tx_task_g, cpu);

		init_llist_head(&tx_task->active);

		init_waitqueue_head(&tx_task->waiting);



		siw_tx_thread[cpu] =

			kthread_run_on_cpu(siw_run_sq,

					   (unsigned long *)(long)cpu,

					   cpu, "siw_tx/%u");

		if (IS_ERR(siw_tx_thread[cpu])) {

			siw_tx_thread[cpu] = NULL;

			continue;

		}

		assigned++;

	}

	return assigned;

}



void siw_stop_tx_threads(void)

{

	int cpu;



	for_each_possible_cpu(cpu) {

		if (siw_tx_thread[cpu]) {

			kthread_stop(siw_tx_thread[cpu]);

			wake_up(&per_cpu(siw_tx_task_g, cpu).waiting);

			siw_tx_thread[cpu] = NULL;

		}

	}

}



int siw_run_sq(void *data)
@@ -1221,9 +1256,6 @@ int siw_run_sq(void *data) 
	struct siw_qp *qp;

	struct tx_task_t *tx_task = &per_cpu(siw_tx_task_g, nr_cpu);



	init_llist_head(&tx_task->active);

	init_waitqueue_head(&tx_task->waiting);



	while (1) {

		struct llist_node *fifo_list = NULL;