patch 'service: fix early move to inactive status' has been queued to stable release 20.11.7

[luca.boccassi at gmail.com]

Hi,

FYI, your patch has been queued to stable release 20.11.7

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 11/07/22. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://github.com/kevintraynor/dpdk-stable

This queued commit can be viewed at:
https://github.com/kevintraynor/dpdk-stable/commit/1cd5de2a59f596d88058f2a46792113308e66bde

Thanks.

Luca Boccassi

---
>From 1cd5de2a59f596d88058f2a46792113308e66bde Mon Sep 17 00:00:00 2001
From: Erik Gabriel Carrillo <erik.g.carrillo at intel.com>
Date: Thu, 20 Oct 2022 14:00:41 -0500
Subject: [PATCH] service: fix early move to inactive status

[ upstream commit 329280c53e6d09002b67e4d052fe27a952bd19cf ]

Assume thread T2 is a service lcore that is in the middle of executing
a service function.  Also, assume thread T1 concurrently calls
rte_service_lcore_stop(), which will set the "service_active_on_lcore"
state to false.  If thread T1 then calls rte_service_may_be_active(),
it can return zero even though T2 is still running the service function.
If T1 then proceeds to free data being used by T2, a crash can ensue.

Move the logic that clears the "service_active_on_lcore" state from the
rte_service_lcore_stop() function to the service_runner_func() to
ensure that we:
- don't let the "service_active_on_lcore" state linger as 1
- don't clear the state early

Fixes: 6550113be62d ("service: fix lingering active status")

Signed-off-by: Erik Gabriel Carrillo <erik.g.carrillo at intel.com>
Acked-by: Harry van Haaren <harry.van.haaren at intel.com>
---
 lib/librte_eal/common/rte_service.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/lib/librte_eal/common/rte_service.c b/lib/librte_eal/common/rte_service.c
index d5e3574ec7..e1ff0d2636 100644
--- a/lib/librte_eal/common/rte_service.c
+++ b/lib/librte_eal/common/rte_service.c
@@ -501,6 +501,12 @@ service_runner_func(void *arg)
 		cs->loops++;
 	}
 
+	/* Switch off this core for all services, to ensure that future
+	 * calls to may_be_active() know this core is switched off.
+	 */
+	for (i = 0; i < RTE_SERVICE_NUM_MAX; i++)
+		cs->service_active_on_lcore[i] = 0;
+
 	/* Use SEQ CST memory ordering to avoid any re-ordering around
 	 * this store, ensuring that once this store is visible, the service
 	 * lcore thread really is done in service cores code.
@@ -797,11 +803,6 @@ rte_service_lcore_stop(uint32_t lcore)
 			__atomic_load_n(&rte_services[i].num_mapped_cores,
 				__ATOMIC_RELAXED));
 
-		/* Switch off this core for all services, to ensure that future
-		 * calls to may_be_active() know this core is switched off.
-		 */
-		cs->service_active_on_lcore[i] = 0;
-
 		/* if the core is mapped, and the service is running, and this
 		 * is the only core that is mapped, the service would cease to
 		 * run if this core stopped, so fail instead.
-- 
2.34.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2022-11-05 17:11:09.436133306 +0000
+++ 0008-service-fix-early-move-to-inactive-status.patch	2022-11-05 17:11:08.578940581 +0000
@@ -1 +1 @@
-From 329280c53e6d09002b67e4d052fe27a952bd19cf Mon Sep 17 00:00:00 2001
+From 1cd5de2a59f596d88058f2a46792113308e66bde Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit 329280c53e6d09002b67e4d052fe27a952bd19cf ]
+
@@ -20 +21,0 @@
-Cc: stable at dpdk.org
@@ -25,2 +26,2 @@
- lib/eal/common/rte_service.c | 13 +++++++------
- 1 file changed, 7 insertions(+), 6 deletions(-)
+ lib/librte_eal/common/rte_service.c | 11 ++++++-----
+ 1 file changed, 6 insertions(+), 5 deletions(-)
@@ -28,22 +29,6 @@
-diff --git a/lib/eal/common/rte_service.c b/lib/eal/common/rte_service.c
-index 81c9514149..bcc2e19077 100644
---- a/lib/eal/common/rte_service.c
-+++ b/lib/eal/common/rte_service.c
-@@ -479,6 +479,7 @@ static int32_t
- service_runner_func(void *arg)
- {
- 	RTE_SET_USED(arg);
-+	uint8_t i;
- 	const int lcore = rte_lcore_id();
- 	struct core_state *cs = &lcore_states[lcore];
- 
-@@ -494,7 +495,6 @@ service_runner_func(void *arg)
- 		const uint64_t service_mask = cs->service_mask;
- 		uint8_t start_id;
- 		uint8_t end_id;
--		uint8_t i;
- 
- 		if (service_mask == 0)
- 			continue;
-@@ -510,6 +510,12 @@ service_runner_func(void *arg)
- 		__atomic_store_n(&cs->loops, cs->loops + 1, __ATOMIC_RELAXED);
+diff --git a/lib/librte_eal/common/rte_service.c b/lib/librte_eal/common/rte_service.c
+index d5e3574ec7..e1ff0d2636 100644
+--- a/lib/librte_eal/common/rte_service.c
++++ b/lib/librte_eal/common/rte_service.c
+@@ -501,6 +501,12 @@ service_runner_func(void *arg)
+ 		cs->loops++;
@@ -61 +46 @@
-@@ -806,11 +812,6 @@ rte_service_lcore_stop(uint32_t lcore)
+@@ -797,11 +803,6 @@ rte_service_lcore_stop(uint32_t lcore)