From: Luc Pelletier <lucp.at.work@gmail.com>
To: olivier.matz@6wind.com, jianfeng.tan@intel.com,
Honnappa.Nagarahalli@arm.com
Cc: dev@dpdk.org, Luc Pelletier <lucp.at.work@gmail.com>, stable@dpdk.org
Subject: [dpdk-stable] [PATCH v3] eal: fix race in ctrl thread creation
Date: Tue, 6 Apr 2021 12:15:35 -0400 [thread overview]
Message-ID: <20210406161534.103272-1-lucp.at.work@gmail.com> (raw)
In-Reply-To: <20210324130422.92357-1-lucp.at.work@gmail.com>
The creation of control threads used a pthread barrier for
synchronization. This patch fixes a race condition where the pthread
barrier could get destroyed while one of the threads has not yet
returned from the pthread_barrier_wait function, which could result in
undefined behaviour. The barrier has been completely removed in favour
of a reference count on the control thread parameters struct.
Fixes: 3a0d465d4c53 ("eal: fix use-after-free on control thread creation")
Cc: jianfeng.tan@intel.com
Cc: stable@dpdk.org
Signed-off-by: Luc Pelletier <lucp.at.work@gmail.com>
---
Hi Olivier,
Hi Honnappa,
Thanks for your input Honnappa. I've made the changes to completely
remove the barrier. However, I didn't move the call to
pthread_setaffinity_np to the control thread; I think we want to report
the result of that function to the caller of rte_ctrl_thread_create and
doing so from ctrl_thread_init would be a lot trickier.
Olivier, what do you think of these changes?
lib/librte_eal/common/eal_common_thread.c | 35 ++++++++---------------
1 file changed, 12 insertions(+), 23 deletions(-)
diff --git a/lib/librte_eal/common/eal_common_thread.c b/lib/librte_eal/common/eal_common_thread.c
index 73a055902..2421066f9 100644
--- a/lib/librte_eal/common/eal_common_thread.c
+++ b/lib/librte_eal/common/eal_common_thread.c
@@ -169,12 +169,11 @@ __rte_thread_uninit(void)
struct rte_thread_ctrl_params {
void *(*start_routine)(void *);
void *arg;
- pthread_barrier_t configured;
+ unsigned int refcnt;
};
static void *ctrl_thread_init(void *arg)
{
- int ret;
struct internal_config *internal_conf =
eal_get_internal_configuration();
rte_cpuset_t *cpuset = &internal_conf->ctrl_cpuset;
@@ -184,11 +183,8 @@ static void *ctrl_thread_init(void *arg)
__rte_thread_init(rte_lcore_id(), cpuset);
- ret = pthread_barrier_wait(¶ms->configured);
- if (ret == PTHREAD_BARRIER_SERIAL_THREAD) {
- pthread_barrier_destroy(¶ms->configured);
+ if (__atomic_sub_fetch(¶ms->refcnt, 1, __ATOMIC_ACQ_REL) == 0)
free(params);
- }
return start_routine(routine_arg);
}
@@ -210,14 +206,11 @@ rte_ctrl_thread_create(pthread_t *thread, const char *name,
params->start_routine = start_routine;
params->arg = arg;
-
- pthread_barrier_init(¶ms->configured, NULL, 2);
+ params->refcnt = 2;
ret = pthread_create(thread, attr, ctrl_thread_init, (void *)params);
- if (ret != 0) {
- free(params);
- return -ret;
- }
+ if (ret != 0)
+ goto fail;
if (name != NULL) {
ret = rte_thread_setname(*thread, name);
@@ -228,24 +221,20 @@ rte_ctrl_thread_create(pthread_t *thread, const char *name,
ret = pthread_setaffinity_np(*thread, sizeof(*cpuset), cpuset);
if (ret)
- goto fail;
+ goto fail_cancel;
- ret = pthread_barrier_wait(¶ms->configured);
- if (ret == PTHREAD_BARRIER_SERIAL_THREAD) {
- pthread_barrier_destroy(¶ms->configured);
+ if (__atomic_sub_fetch(¶ms->refcnt, 1, __ATOMIC_ACQ_REL) == 0)
free(params);
- }
return 0;
-fail:
- if (PTHREAD_BARRIER_SERIAL_THREAD ==
- pthread_barrier_wait(¶ms->configured)) {
- pthread_barrier_destroy(¶ms->configured);
- free(params);
- }
+fail_cancel:
pthread_cancel(*thread);
pthread_join(*thread, NULL);
+
+fail:
+ free(params);
+
return -ret;
}
--
2.25.1
next prev parent reply other threads:[~2021-04-06 16:17 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-24 13:04 [dpdk-stable] [PATCH] eal: fix possible UB on creation of ctrl thread Luc Pelletier
2021-03-25 11:27 ` [dpdk-stable] [PATCH v2] eal: fix race in ctrl thread creation Olivier Matz
2021-03-25 14:42 ` Luc Pelletier
2021-04-02 4:34 ` [dpdk-stable] [dpdk-dev] " Honnappa Nagarahalli
2021-04-06 16:15 ` Luc Pelletier [this message]
2021-04-06 21:10 ` [dpdk-stable] [PATCH v3] " Honnappa Nagarahalli
2021-04-07 12:35 ` [dpdk-stable] [PATCH v4] " Luc Pelletier
2021-04-07 12:53 ` [dpdk-stable] [PATCH v5] " Luc Pelletier
2021-04-07 13:22 ` Luc Pelletier
2021-04-07 13:31 ` Olivier Matz
2021-04-07 14:42 ` [dpdk-stable] [PATCH v6] " Luc Pelletier
2021-04-07 14:57 ` Olivier Matz
2021-04-07 15:29 ` [dpdk-stable] [PATCH v7] " Luc Pelletier
2021-04-07 17:15 ` Honnappa Nagarahalli
2021-04-07 15:15 ` [dpdk-stable] [PATCH v5] " Honnappa Nagarahalli
2021-04-07 20:16 ` [dpdk-stable] [PATCH 1/2] " Luc Pelletier
2021-04-08 14:17 ` Olivier Matz
2021-04-08 17:06 ` Honnappa Nagarahalli
2021-04-07 20:16 ` [dpdk-stable] [PATCH 2/2] eal: fix hang in ctrl thread creation error logic Luc Pelletier
2021-04-08 14:20 ` Olivier Matz
2021-04-08 18:01 ` Luc Pelletier
2021-04-09 8:13 ` [dpdk-stable] [dpdk-dev] " David Marchand
2021-04-08 17:07 ` [dpdk-stable] " Honnappa Nagarahalli
2021-04-09 14:34 ` David Marchand
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