From af68c1d699be6c369e296b775bdbf13ae18b79cc Mon Sep 17 00:00:00 2001 From: Luc Pelletier Date: Wed, 7 Apr 2021 16:16:06 -0400 Subject: [PATCH] eal: fix hang in control thread creation The affinity of a control thread is set after it has been launched. If setting the affinity fails, pthread_cancel is called followed by a call to pthread_join, which can hang forever if the thread's start routine doesn't call a pthread cancellation point. This patch modifies the logic so that the control thread exits gracefully if the affinity cannot be set successfully and removes the call to pthread_cancel. Fixes: 6383d2642b62 ("eal: set name when creating a control thread") Cc: stable@dpdk.org Signed-off-by: Luc Pelletier Acked-by: Olivier Matz Reviewed-by: Honnappa Nagarahalli --- lib/librte_eal/common/eal_common_thread.c | 29 +++++++++++++---------- 1 file changed, 17 insertions(+), 12 deletions(-) diff --git a/lib/librte_eal/common/eal_common_thread.c b/lib/librte_eal/common/eal_common_thread.c index 3347e91bf2..03dbcd9e86 100644 --- a/lib/librte_eal/common/eal_common_thread.c +++ b/lib/librte_eal/common/eal_common_thread.c @@ -187,14 +187,18 @@ static void *ctrl_thread_init(void *arg) eal_get_internal_configuration(); rte_cpuset_t *cpuset = &internal_conf->ctrl_cpuset; struct rte_thread_ctrl_params *params = arg; - void *(*start_routine)(void *) = params->start_routine; + void *(*start_routine)(void *); void *routine_arg = params->arg; __rte_thread_init(rte_lcore_id(), cpuset); pthread_barrier_wait(¶ms->configured); + start_routine = params->start_routine; ctrl_params_free(params); + if (start_routine == NULL) + return NULL; + return start_routine(routine_arg); } @@ -218,14 +222,12 @@ rte_ctrl_thread_create(pthread_t *thread, const char *name, params->refcnt = 2; ret = pthread_barrier_init(¶ms->configured, NULL, 2); - if (ret != 0) { - free(params); - return -ret; - } + if (ret != 0) + goto fail_no_barrier; ret = pthread_create(thread, attr, ctrl_thread_init, (void *)params); if (ret != 0) - goto fail; + goto fail_with_barrier; if (name != NULL) { ret = rte_thread_setname(*thread, name); @@ -236,19 +238,22 @@ rte_ctrl_thread_create(pthread_t *thread, const char *name, ret = pthread_setaffinity_np(*thread, sizeof(*cpuset), cpuset); if (ret != 0) - goto fail_cancel; + params->start_routine = NULL; pthread_barrier_wait(¶ms->configured); ctrl_params_free(params); - return 0; + if (ret != 0) + /* start_routine has been set to NULL above; */ + /* ctrl thread will exit immediately */ + pthread_join(*thread, NULL); -fail_cancel: - pthread_cancel(*thread); - pthread_join(*thread, NULL); + return -ret; -fail: +fail_with_barrier: pthread_barrier_destroy(¶ms->configured); + +fail_no_barrier: free(params); return -ret; -- 2.20.1