[dpdk-stable] patch 'eal/freebsd: fix queuing duplicate alarm callbacks' has been queued to stable release 19.11.3

[luca.boccassi at gmail.com]

Hi,

FYI, your patch has been queued to stable release 19.11.3

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 05/21/20. 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.

Thanks.

Luca Boccassi

---
>From 46cd0c98bbb46a3548f291d800b7f80e1ac4965e Mon Sep 17 00:00:00 2001
From: Mit Matelske <mit at pt.net>
Date: Wed, 20 Nov 2019 14:10:56 -0600
Subject: [PATCH] eal/freebsd: fix queuing duplicate alarm callbacks

[ upstream commit bcf789da7335b80e792ba926b5a95a12fa2e1e9a ]

The source callback list grows infinitely when more than alarm
is queued.

This fix recognizes that an alarm interrupt in FreeBSD should never
have more than one callback on its list, so if
rte_intr_callback_register() is called with an interrupt handle type
of RTE_INTR_HANDLE_ALARM, so if such an interrupt type already has a
non-empty list, then a new callback is not created, but the kevent
timer is restarted properly.

Fixes: 23150bd8d8a8 ("eal/bsd: add interrupt thread")

Signed-off-by: Mit Matelske <mit at pt.net>
Acked-by: Bruce Richardson <bruce.richardson at intel.com>
---
 lib/librte_eal/freebsd/eal/eal_interrupts.c | 79 +++++++++++----------
 1 file changed, 43 insertions(+), 36 deletions(-)

diff --git a/lib/librte_eal/freebsd/eal/eal_interrupts.c b/lib/librte_eal/freebsd/eal/eal_interrupts.c
index f6831b7902..3fee762be9 100644
--- a/lib/librte_eal/freebsd/eal/eal_interrupts.c
+++ b/lib/librte_eal/freebsd/eal/eal_interrupts.c
@@ -83,9 +83,9 @@ int
 rte_intr_callback_register(const struct rte_intr_handle *intr_handle,
 		rte_intr_callback_fn cb, void *cb_arg)
 {
-	struct rte_intr_callback *callback = NULL;
-	struct rte_intr_source *src = NULL;
-	int ret, add_event;
+	struct rte_intr_callback *callback;
+	struct rte_intr_source *src;
+	int ret, add_event = 0;
 
 	/* first do parameter checking */
 	if (intr_handle == NULL || intr_handle->fd < 0 || cb == NULL) {
@@ -98,47 +98,53 @@ rte_intr_callback_register(const struct rte_intr_handle *intr_handle,
 		return -ENODEV;
 	}
 
-	/* allocate a new interrupt callback entity */
-	callback = calloc(1, sizeof(*callback));
-	if (callback == NULL) {
-		RTE_LOG(ERR, EAL, "Can not allocate memory\n");
-		return -ENOMEM;
-	}
-	callback->cb_fn = cb;
-	callback->cb_arg = cb_arg;
-	callback->pending_delete = 0;
-	callback->ucb_fn = NULL;
-
 	rte_spinlock_lock(&intr_lock);
 
-	/* check if there is at least one callback registered for the fd */
+	/* find the source for this intr_handle */
 	TAILQ_FOREACH(src, &intr_sources, next) {
-		if (src->intr_handle.fd == intr_handle->fd) {
-			/* we had no interrupts for this */
-			if (TAILQ_EMPTY(&src->callbacks))
-				add_event = 1;
-
-			TAILQ_INSERT_TAIL(&(src->callbacks), callback, next);
-			ret = 0;
+		if (src->intr_handle.fd == intr_handle->fd)
 			break;
-		}
 	}
 
-	/* no existing callbacks for this - add new source */
-	if (src == NULL) {
-		src = calloc(1, sizeof(*src));
-		if (src == NULL) {
+	/* if this is an alarm interrupt and it already has a callback,
+	 * then we don't want to create a new callback because the only
+	 * thing on the list should be eal_alarm_callback() and we may
+	 * be called just to reset the timer.
+	 */
+	if (src != NULL && src->intr_handle.type == RTE_INTR_HANDLE_ALARM &&
+		 !TAILQ_EMPTY(&src->callbacks)) {
+		callback = NULL;
+	} else {
+		/* allocate a new interrupt callback entity */
+		callback = calloc(1, sizeof(*callback));
+		if (callback == NULL) {
 			RTE_LOG(ERR, EAL, "Can not allocate memory\n");
 			ret = -ENOMEM;
 			goto fail;
-		} else {
-			src->intr_handle = *intr_handle;
-			TAILQ_INIT(&src->callbacks);
-			TAILQ_INSERT_TAIL(&(src->callbacks), callback, next);
-			TAILQ_INSERT_TAIL(&intr_sources, src, next);
+		}
+		callback->cb_fn = cb;
+		callback->cb_arg = cb_arg;
+		callback->pending_delete = 0;
+		callback->ucb_fn = NULL;
+
+		if (src == NULL) {
+			src = calloc(1, sizeof(*src));
+			if (src == NULL) {
+				RTE_LOG(ERR, EAL, "Can not allocate memory\n");
+				ret = -ENOMEM;
+				goto fail;
+			} else {
+				src->intr_handle = *intr_handle;
+				TAILQ_INIT(&src->callbacks);
+				TAILQ_INSERT_TAIL(&intr_sources, src, next);
+			}
+		}
+
+		/* we had no interrupts for this */
+		if (TAILQ_EMPTY(&src->callbacks))
 			add_event = 1;
-			ret = 0;
-		}
+
+		TAILQ_INSERT_TAIL(&(src->callbacks), callback, next);
 	}
 
 	/* add events to the queue. timer events are special as we need to
@@ -178,11 +184,12 @@ rte_intr_callback_register(const struct rte_intr_handle *intr_handle,
 	}
 	rte_spinlock_unlock(&intr_lock);
 
-	return ret;
+	return 0;
 fail:
 	/* clean up */
 	if (src != NULL) {
-		TAILQ_REMOVE(&(src->callbacks), callback, next);
+		if (callback != NULL)
+			TAILQ_REMOVE(&(src->callbacks), callback, next);
 		if (TAILQ_EMPTY(&(src->callbacks))) {
 			TAILQ_REMOVE(&intr_sources, src, next);
 			free(src);
-- 
2.20.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2020-05-19 13:56:20.973900822 +0100
+++ 0052-eal-freebsd-fix-queuing-duplicate-alarm-callbacks.patch	2020-05-19 13:56:18.283502971 +0100
@@ -1,8 +1,10 @@
-From bcf789da7335b80e792ba926b5a95a12fa2e1e9a Mon Sep 17 00:00:00 2001
+From 46cd0c98bbb46a3548f291d800b7f80e1ac4965e Mon Sep 17 00:00:00 2001
 From: Mit Matelske <mit at pt.net>
 Date: Wed, 20 Nov 2019 14:10:56 -0600
 Subject: [PATCH] eal/freebsd: fix queuing duplicate alarm callbacks
 
+[ upstream commit bcf789da7335b80e792ba926b5a95a12fa2e1e9a ]
+
 The source callback list grows infinitely when more than alarm
 is queued.
 
@@ -14,7 +16,6 @@
 timer is restarted properly.
 
 Fixes: 23150bd8d8a8 ("eal/bsd: add interrupt thread")
-Cc: stable at dpdk.org
 
 Signed-off-by: Mit Matelske <mit at pt.net>
 Acked-by: Bruce Richardson <bruce.richardson at intel.com>
@@ -23,7 +24,7 @@
  1 file changed, 43 insertions(+), 36 deletions(-)
 
 diff --git a/lib/librte_eal/freebsd/eal/eal_interrupts.c b/lib/librte_eal/freebsd/eal/eal_interrupts.c
-index ce2a27b4a5..00991f26a9 100644
+index f6831b7902..3fee762be9 100644
 --- a/lib/librte_eal/freebsd/eal/eal_interrupts.c
 +++ b/lib/librte_eal/freebsd/eal/eal_interrupts.c
 @@ -83,9 +83,9 @@ int