timer: fix corruption with reset

When timer_cb resets another running timer on the same lcore,
the list of expired timers is chained to the pending-list.
This commit prevents a running timer from being reset
by not its own timer_cb.

Fixes: a4b7a5a45cf5 ("timer: fix race condition")

Signed-off-by: Hiroyuki Mikita <h.mikita89@gmail.com>
Acked-by: Robert Sanford <rsanford@akamai.com>

diff --git a/lib/librte_timer/rte_timer.c b/lib/librte_timer/rte_timer.c
index 3f21f2d..43da836 100644 (file)
--- a/lib/librte_timer/rte_timer.c
+++ b/lib/librte_timer/rte_timer.c
@@ -69,6 +69,9 @@ struct priv_timer {
 
        unsigned prev_lcore;              /**< used for lcore round robin */
 
+       /** running timer on this lcore now */
+       struct rte_timer *running_tim;
+
 #ifdef RTE_LIBRTE_TIMER_DEBUG
        /** per-lcore statistics */
        struct rte_timer_debug_stats stats;
@@ -135,9 +138,12 @@ timer_set_config_state(struct rte_timer *tim,
        while (success == 0) {
                prev_status.u32 = tim->status.u32;
 
-               /* timer is running on another core, exit */
+               /* timer is running on another core
+                * or ready to run on local core, exit
+                */
                if (prev_status.state == RTE_TIMER_RUNNING &&
-                   prev_status.owner != (uint16_t)lcore_id)
+                   (prev_status.owner != (uint16_t)lcore_id ||
+                    tim != priv_timer[lcore_id].running_tim))
                        return -1;
 
                /* timer is being configured on another core */
@@ -581,6 +587,7 @@ void rte_timer_manage(void)
        for (tim = run_first_tim; tim != NULL; tim = next_tim) {
                next_tim = tim->sl_next[0];
                priv_timer[lcore_id].updated = 0;
+               priv_timer[lcore_id].running_tim = tim;
 
                /* execute callback function with list unlocked */
                tim->f(tim, tim->arg);
@@ -611,6 +618,7 @@ void rte_timer_manage(void)
                        rte_spinlock_unlock(&priv_timer[lcore_id].list_lock);
                }
        }
+       priv_timer[lcore_id].running_tim = NULL;
 }
 
 /* dump statistics about timers */