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From: Sarosh Arif <sarosh.arif@emumba.com>
To: rsanford@akamai.com, erik.g.carrillo@intel.com, dev@dpdk.org
Cc: stable@dpdk.org, Sarosh Arif <sarosh.arif@emumba.com>,
	h.mikita89@gmail.com
Subject: [dpdk-dev] [PATCH v3] lib/librte_timer:fix corruption with reset
Date: Fri, 10 Jul 2020 11:59:54 +0500
Message-ID: <20200710065954.4937-1-sarosh.arif@emumba.com> (raw)
In-Reply-To: <20200707090320.2463-1-sarosh.arif@emumba.com>

If the user tries to reset/stop some other timer in it's callback
function, which is also about to expire, using 
rte_timer_reset_sync/rte_timer_stop_sync the application goes into
an infinite loop. This happens because 
rte_timer_reset_sync/rte_timer_stop_sync loop until the timer 
resets/stops and there is check inside timer_set_config_state which
prevents a running timer from being reset/stopped by not it's own 
timer_cb. Therefore timer_set_config_state returns -1 due to which 
rte_timer_reset returns -1 and rte_timer_reset_sync goes into an 
infinite loop. 

The soloution to this problem is to return -1 from 
rte_timer_reset_sync/rte_timer_stop_sync in case the user tries to 
reset/stop some other timer in it's callback function.

Bugzilla ID: 491
Fixes: 20d159f20543 ("timer: fix corruption with reset")
Cc: h.mikita89@gmail.com
Signed-off-by: Sarosh Arif <sarosh.arif@emumba.com>
---
v2: remove line continuations
v3: separate code and declarations
---
 lib/librte_timer/rte_timer.c | 26 ++++++++++++++++++++++++--
 lib/librte_timer/rte_timer.h |  4 ++--
 2 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/lib/librte_timer/rte_timer.c b/lib/librte_timer/rte_timer.c
index 6d19ce469..0cd3e2c86 100644
--- a/lib/librte_timer/rte_timer.c
+++ b/lib/librte_timer/rte_timer.c
@@ -576,14 +576,24 @@ rte_timer_alt_reset(uint32_t timer_data_id, struct rte_timer *tim,
 }
 
 /* loop until rte_timer_reset() succeed */
-void
+int
 rte_timer_reset_sync(struct rte_timer *tim, uint64_t ticks,
 		     enum rte_timer_type type, unsigned tim_lcore,
 		     rte_timer_cb_t fct, void *arg)
 {
+	struct rte_timer_data *timer_data;
+	TIMER_DATA_VALID_GET_OR_ERR_RET(default_data_id, timer_data, -EINVAL);
+
+	if (tim->status.state == RTE_TIMER_RUNNING &&
+	(tim->status.owner != (uint16_t)tim_lcore ||
+	tim != timer_data->priv_timer[tim_lcore].running_tim))
+		return -1;
+
 	while (rte_timer_reset(tim, ticks, type, tim_lcore,
 			       fct, arg) != 0)
 		rte_pause();
+
+	return 0;
 }
 
 static int
@@ -642,11 +652,23 @@ rte_timer_alt_stop(uint32_t timer_data_id, struct rte_timer *tim)
 }
 
 /* loop until rte_timer_stop() succeed */
-void
+int
 rte_timer_stop_sync(struct rte_timer *tim)
 {
+	struct rte_timer_data *timer_data;
+	unsigned int lcore_id = rte_lcore_id();
+
+	TIMER_DATA_VALID_GET_OR_ERR_RET(default_data_id, timer_data, -EINVAL);
+
+	if (tim->status.state == RTE_TIMER_RUNNING &&
+	(tim->status.owner != (uint16_t)lcore_id ||
+	tim != timer_data->priv_timer[lcore_id].running_tim))
+		return -1;
+
 	while (rte_timer_stop(tim) != 0)
 		rte_pause();
+
+	return 0;
 }
 
 /* Test the PENDING status of the timer handle tim */
diff --git a/lib/librte_timer/rte_timer.h b/lib/librte_timer/rte_timer.h
index c6b3d450d..392ca423d 100644
--- a/lib/librte_timer/rte_timer.h
+++ b/lib/librte_timer/rte_timer.h
@@ -275,7 +275,7 @@ int rte_timer_reset(struct rte_timer *tim, uint64_t ticks,
  * @param arg
  *   The user argument of the callback function.
  */
-void
+int
 rte_timer_reset_sync(struct rte_timer *tim, uint64_t ticks,
 		     enum rte_timer_type type, unsigned tim_lcore,
 		     rte_timer_cb_t fct, void *arg);
@@ -314,7 +314,7 @@ int rte_timer_stop(struct rte_timer *tim);
  * @param tim
  *   The timer handle.
  */
-void rte_timer_stop_sync(struct rte_timer *tim);
+int rte_timer_stop_sync(struct rte_timer *tim);
 
 /**
  * Test if a timer is pending.
-- 
2.17.1


  parent reply	other threads:[~2020-07-10  7:01 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-07  9:03 [dpdk-dev] [PATCH] " Sarosh Arif
2020-07-07 16:09 ` Stephen Hemminger
2020-07-08  5:06 ` [dpdk-dev] [PATCH v2] " Sarosh Arif
2020-07-08 15:07   ` Stephen Hemminger
2020-07-09  7:05     ` Sarosh Arif
2020-07-08 15:08   ` Stephen Hemminger
2020-07-09  7:02     ` Sarosh Arif
2020-07-10  6:59 ` Sarosh Arif [this message]
2020-07-10 15:19   ` [dpdk-dev] [PATCH v3] " Stephen Hemminger
2020-07-28 19:04   ` Carrillo, Erik G

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