patch 'timer: fix stopping all timers' has been queued to stable release 19.11.14

[christian.ehrhardt at canonical.com]

Hi,

FYI, your patch has been queued to stable release 19.11.14

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 11/18/22. 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/cpaelzer/dpdk-stable-queue

This queued commit can be viewed at:
https://github.com/cpaelzer/dpdk-stable-queue/commit/5915ced554f186a3e9397ca32c368a7535ef4adb

Thanks.

Christian Ehrhardt <christian.ehrhardt at canonical.com>

---
>From 5915ced554f186a3e9397ca32c368a7535ef4adb Mon Sep 17 00:00:00 2001
From: Naga Harish K S V <s.v.naga.harish.k at intel.com>
Date: Wed, 14 Sep 2022 10:33:18 -0500
Subject: [PATCH] timer: fix stopping all timers

[ upstream commit eb63c85d7bae32fdc1cbafcd91e88bd6515c39cf ]

There is a possibility of deadlock in this API,
as same spinlock is tried to be acquired in nested manner.

If the lcore that is stopping the timer is different from the lcore
that owns the timer, the timer list lock is acquired in timer_del(),
even if local_is_locked is true. Because the same lock was already
acquired in rte_timer_stop_all(), the thread will hang.

This patch removes the acquisition of nested lock.

Fixes: 821c51267bcd63a ("timer: add function to stop all timers in a list")

Signed-off-by: Naga Harish K S V <s.v.naga.harish.k at intel.com>
Acked-by: Erik Gabriel Carrillo <erik.g.carrillo at intel.com>
---
 lib/librte_timer/rte_timer.c | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/lib/librte_timer/rte_timer.c b/lib/librte_timer/rte_timer.c
index 99862a3ba1..7ea27f9878 100644
--- a/lib/librte_timer/rte_timer.c
+++ b/lib/librte_timer/rte_timer.c
@@ -573,7 +573,7 @@ rte_timer_reset_sync(struct rte_timer *tim, uint64_t ticks,
 }
 
 static int
-__rte_timer_stop(struct rte_timer *tim, int local_is_locked,
+__rte_timer_stop(struct rte_timer *tim,
 		 struct rte_timer_data *timer_data)
 {
 	union rte_timer_status prev_status, status;
@@ -595,7 +595,7 @@ __rte_timer_stop(struct rte_timer *tim, int local_is_locked,
 
 	/* remove it from list */
 	if (prev_status.state == RTE_TIMER_PENDING) {
-		timer_del(tim, prev_status, local_is_locked, priv_timer);
+		timer_del(tim, prev_status, 0, priv_timer);
 		__TIMER_STAT_ADD(priv_timer, pending, -1);
 	}
 
@@ -622,7 +622,7 @@ rte_timer_alt_stop(uint32_t timer_data_id, struct rte_timer *tim)
 
 	TIMER_DATA_VALID_GET_OR_ERR_RET(timer_data_id, timer_data, -EINVAL);
 
-	return __rte_timer_stop(tim, 0, timer_data);
+	return __rte_timer_stop(tim, timer_data);
 }
 
 /* loop until rte_timer_stop() succeed */
@@ -961,21 +961,16 @@ rte_timer_stop_all(uint32_t timer_data_id, unsigned int *walk_lcores,
 		walk_lcore = walk_lcores[i];
 		priv_timer = &timer_data->priv_timer[walk_lcore];
 
-		rte_spinlock_lock(&priv_timer->list_lock);
-
 		for (tim = priv_timer->pending_head.sl_next[0];
 		     tim != NULL;
 		     tim = next_tim) {
 			next_tim = tim->sl_next[0];
 
-			/* Call timer_stop with lock held */
-			__rte_timer_stop(tim, 1, timer_data);
+			__rte_timer_stop(tim, timer_data);
 
 			if (f)
 				f(tim, f_arg);
 		}
-
-		rte_spinlock_unlock(&priv_timer->list_lock);
 	}
 
 	return 0;
-- 
2.38.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2022-11-11 12:35:05.814217310 +0100
+++ 0029-timer-fix-stopping-all-timers.patch	2022-11-11 12:35:04.773192062 +0100
@@ -1 +1 @@
-From eb63c85d7bae32fdc1cbafcd91e88bd6515c39cf Mon Sep 17 00:00:00 2001
+From 5915ced554f186a3e9397ca32c368a7535ef4adb Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit eb63c85d7bae32fdc1cbafcd91e88bd6515c39cf ]
+
@@ -17 +18,0 @@
-Cc: stable at dpdk.org
@@ -22 +23 @@
- lib/timer/rte_timer.c | 13 ++++---------
+ lib/librte_timer/rte_timer.c | 13 ++++---------
@@ -25,5 +26,5 @@
-diff --git a/lib/timer/rte_timer.c b/lib/timer/rte_timer.c
-index 9994813d0d..85d67573eb 100644
---- a/lib/timer/rte_timer.c
-+++ b/lib/timer/rte_timer.c
-@@ -580,7 +580,7 @@ rte_timer_reset_sync(struct rte_timer *tim, uint64_t ticks,
+diff --git a/lib/librte_timer/rte_timer.c b/lib/librte_timer/rte_timer.c
+index 99862a3ba1..7ea27f9878 100644
+--- a/lib/librte_timer/rte_timer.c
++++ b/lib/librte_timer/rte_timer.c
+@@ -573,7 +573,7 @@ rte_timer_reset_sync(struct rte_timer *tim, uint64_t ticks,
@@ -38 +39 @@
-@@ -602,7 +602,7 @@ __rte_timer_stop(struct rte_timer *tim, int local_is_locked,
+@@ -595,7 +595,7 @@ __rte_timer_stop(struct rte_timer *tim, int local_is_locked,
@@ -47 +48 @@
-@@ -631,7 +631,7 @@ rte_timer_alt_stop(uint32_t timer_data_id, struct rte_timer *tim)
+@@ -622,7 +622,7 @@ rte_timer_alt_stop(uint32_t timer_data_id, struct rte_timer *tim)
@@ -56 +57 @@
-@@ -987,21 +987,16 @@ rte_timer_stop_all(uint32_t timer_data_id, unsigned int *walk_lcores,
+@@ -961,21 +961,16 @@ rte_timer_stop_all(uint32_t timer_data_id, unsigned int *walk_lcores,