[v2] lib/librte_timer:fix corruption with reset
diff mbox series

Message ID 20200708050626.23512-1-sarosh.arif@emumba.com
State Superseded
Delegated to: Thomas Monjalon
Headers show
Series
  • [v2] lib/librte_timer:fix corruption with reset
Related show

Checks

Context Check Description
ci/iol-intel-Performance success Performance Testing PASS
ci/iol-testing success Testing PASS
ci/Intel-compilation success Compilation OK
ci/iol-broadcom-Performance success Performance Testing PASS
ci/travis-robot warning Travis build: failed
ci/checkpatch warning coding style issues

Commit Message

Sarosh Arif July 8, 2020, 5:06 a.m. UTC
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
---
 lib/librte_timer/rte_timer.c | 25 +++++++++++++++++++++++--
 lib/librte_timer/rte_timer.h |  4 ++--
 2 files changed, 25 insertions(+), 4 deletions(-)

Comments

Stephen Hemminger July 8, 2020, 3:07 p.m. UTC | #1
On Wed,  8 Jul 2020 10:06:26 +0500
Sarosh Arif <sarosh.arif@emumba.com> wrote:

>  /* 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)

This is an API change and needs to wait until a breaking release like 20.11.
Also most applications won't test the result.
Stephen Hemminger July 8, 2020, 3:08 p.m. UTC | #2
On Wed,  8 Jul 2020 10:06:26 +0500
Sarosh Arif <sarosh.arif@emumba.com> wrote:

>  rte_timer_stop_sync(struct rte_timer *tim)
>  {
> +	struct rte_timer_data *timer_data;
> +	TIMER_DATA_VALID_GET_OR_ERR_RET(default_data_id, timer_data, -EINVAL);
> +	unsigned int lcore_id = rte_lcore_id();

This mixing code and declarations. since the macro has a return statement.

Maybe:

	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);
Sarosh Arif July 9, 2020, 7:02 a.m. UTC | #3
On Wed, Jul 8, 2020 at 8:08 PM Stephen Hemminger <stephen@networkplumber.org>
wrote:

> On Wed,  8 Jul 2020 10:06:26 +0500
> Sarosh Arif <sarosh.arif@emumba.com> wrote:
>
> >  rte_timer_stop_sync(struct rte_timer *tim)
> >  {
> > +     struct rte_timer_data *timer_data;
> > +     TIMER_DATA_VALID_GET_OR_ERR_RET(default_data_id, timer_data,
> -EINVAL);
> > +     unsigned int lcore_id = rte_lcore_id();
>
> This mixing code and declarations. since the macro has a return statement.
>
> Maybe:
>
>         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);
>
I will fix this in the next version.
Sarosh Arif July 9, 2020, 7:05 a.m. UTC | #4
On Wed, Jul 8, 2020 at 8:07 PM Stephen Hemminger <stephen@networkplumber.org>
wrote:

> On Wed,  8 Jul 2020 10:06:26 +0500
> Sarosh Arif <sarosh.arif@emumba.com> wrote:
>
> >  /* 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)
>
> This is an API change and needs to wait until a breaking release like
> 20.11.
>
Okay,waiting till the next breaking release sounds fine to me.


> Also most applications won't test the result.
>

Patch
diff mbox series

diff --git a/lib/librte_timer/rte_timer.c b/lib/librte_timer/rte_timer.c
index 6d19ce469..be86385a1 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 +652,22 @@  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;
+	TIMER_DATA_VALID_GET_OR_ERR_RET(default_data_id, timer_data, -EINVAL);
+	unsigned int lcore_id = rte_lcore_id();
+
+	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.