[dpdk-stable] [PATCH v3] telemetry: fix race in telemetry control thread creation

[dpdk-stable] [PATCH v3] telemetry: fix race in telemetry control thread creation

[Alvin Zhang]

From: Alvin Zhang <alvinzhx@intel.com>

Before the caller returns from function "rte_ctrl_thread_create",
the newly created thread may have ran, and because the thread
control flag was not set before, the new thread may exit soon.
This is not what the developer expected.

This patch puts the setting thread control flag to the place that
before creating new thread.

Reported-at: https://bugs.dpdk.org/show_bug.cgi?id=731
Fixes: 8877ac688b52 ("telemetry: introduce infrastructure")
Cc: stable@dpdk.org

Signed-off-by: Alvin Zhang <alvinzhx@intel.com>
---

v2, v3: update commit log
---
 lib/librte_telemetry/rte_telemetry.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/librte_telemetry/rte_telemetry.c b/lib/librte_telemetry/rte_telemetry.c
index eb20cc6..98d5f91 100644
--- a/lib/librte_telemetry/rte_telemetry.c
+++ b/lib/librte_telemetry/rte_telemetry.c
@@ -1005,10 +1005,10 @@ struct json_data {
 	}
 	TAILQ_INIT(&static_telemetry->client_list_head);
 
+	static_telemetry->thread_status = 1;
 	ret = rte_ctrl_thread_create(&static_telemetry->thread_id,
 		telemetry_ctrl_thread, &attr, rte_telemetry_run_thread_func,
 		(void *)static_telemetry);
-	static_telemetry->thread_status = 1;
 
 	if (ret < 0) {
 		ret = rte_telemetry_cleanup();
-- 
1.8.3.1

Re: [dpdk-stable] [PATCH v3] telemetry: fix race in telemetry control thread creation

[Christian Ehrhardt]

On Tue, Jul 13, 2021 at 8:16 AM Alvin Zhang <alvinx.zhang@intel.com> wrote:
>
> From: Alvin Zhang <alvinzhx@intel.com>
>

This was missing the 19.11 tag and was thereby missed.
It came back via the -rc1 tests of 19.11.10 as it listed the bug again.
Applied now.

> Before the caller returns from function "rte_ctrl_thread_create",
> the newly created thread may have ran, and because the thread
> control flag was not set before, the new thread may exit soon.
> This is not what the developer expected.
>
> This patch puts the setting thread control flag to the place that
> before creating new thread.
>
> Reported-at: https://bugs.dpdk.org/show_bug.cgi?id=731
> Fixes: 8877ac688b52 ("telemetry: introduce infrastructure")
> Cc: stable@dpdk.org
>
> Signed-off-by: Alvin Zhang <alvinzhx@intel.com>
> ---
>
> v2, v3: update commit log
> ---
>  lib/librte_telemetry/rte_telemetry.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/lib/librte_telemetry/rte_telemetry.c b/lib/librte_telemetry/rte_telemetry.c
> index eb20cc6..98d5f91 100644
> --- a/lib/librte_telemetry/rte_telemetry.c
> +++ b/lib/librte_telemetry/rte_telemetry.c
> @@ -1005,10 +1005,10 @@ struct json_data {
>         }
>         TAILQ_INIT(&static_telemetry->client_list_head);
>
> +       static_telemetry->thread_status = 1;
>         ret = rte_ctrl_thread_create(&static_telemetry->thread_id,
>                 telemetry_ctrl_thread, &attr, rte_telemetry_run_thread_func,
>                 (void *)static_telemetry);
> -       static_telemetry->thread_status = 1;
>
>         if (ret < 0) {
>                 ret = rte_telemetry_cleanup();
> --
> 1.8.3.1
>


-- 
Christian Ehrhardt
Staff Engineer, Ubuntu Server
Canonical Ltd