Compiler could generate non-atomic stores for whole table entry
updating. This may cause incorrect nexthop to be returned, if
the byte with valid flag is updated prior to the byte with next
hot is updated.
Changed to use atomic store to update whole table entry.
Suggested-by: Medvedkin Vladimir <vladimir.medved...@intel.com>
Signed-off-by: Ruifeng Wang <ruifeng.w...@arm.com>
Reviewed-by: Gavin Hu <gavin...@arm.com>
---
v4: initial version
lib/librte_lpm/rte_lpm.c | 34 ++++++++++++++++++++++++----------
1 file changed, 24 insertions(+), 10 deletions(-)
diff --git a/lib/librte_lpm/rte_lpm.c b/lib/librte_lpm/rte_lpm.c
index baa6e7460..5d1dbd7e6 100644
--- a/lib/librte_lpm/rte_lpm.c
+++ b/lib/librte_lpm/rte_lpm.c
@@ -767,7 +767,9 @@ add_depth_small_v20(struct rte_lpm_v20 *lpm, uint32_t ip,
uint8_t depth,
* Setting tbl8 entry in one go to avoid
* race conditions
*/
- lpm->tbl8[j] = new_tbl8_entry;
+ __atomic_store(&lpm->tbl8[j],
+ &new_tbl8_entry,
+ __ATOMIC_RELAXED);
continue;
}
@@ -837,7 +839,9 @@ add_depth_small_v1604(struct rte_lpm *lpm, uint32_t ip,
uint8_t depth,
* Setting tbl8 entry in one go to avoid
* race conditions
*/
- lpm->tbl8[j] = new_tbl8_entry;
+ __atomic_store(&lpm->tbl8[j],
+ &new_tbl8_entry,
+ __ATOMIC_RELAXED);
continue;
}
@@ -965,7 +969,8 @@ add_depth_big_v20(struct rte_lpm_v20 *lpm, uint32_t
ip_masked, uint8_t depth,
* Setting tbl8 entry in one go to avoid race
* condition
*/
- lpm->tbl8[i] = new_tbl8_entry;
+ __atomic_store(&lpm->tbl8[i], &new_tbl8_entry,
+ __ATOMIC_RELAXED);
continue;
}
@@ -1100,7 +1105,8 @@ add_depth_big_v1604(struct rte_lpm *lpm, uint32_t
ip_masked, uint8_t depth,
* Setting tbl8 entry in one go to avoid race
* condition
*/
- lpm->tbl8[i] = new_tbl8_entry;
+ __atomic_store(&lpm->tbl8[i], &new_tbl8_entry,
+ __ATOMIC_RELAXED);
continue;
}
@@ -1393,7 +1399,9 @@ delete_depth_small_v20(struct rte_lpm_v20 *lpm, uint32_t
ip_masked,
RTE_LPM_TBL8_GROUP_NUM_ENTRIES); j++) {
if (lpm->tbl8[j].depth <= depth)
- lpm->tbl8[j] = new_tbl8_entry;
+ __atomic_store(&lpm->tbl8[j],
+ &new_tbl8_entry,
+ __ATOMIC_RELAXED);
}
}
}
@@ -1490,7 +1498,9 @@ delete_depth_small_v1604(struct rte_lpm *lpm, uint32_t
ip_masked,
RTE_LPM_TBL8_GROUP_NUM_ENTRIES); j++) {
if (lpm->tbl8[j].depth <= depth)
- lpm->tbl8[j] = new_tbl8_entry;
+ __atomic_store(&lpm->tbl8[j],
+ &new_tbl8_entry,
+ __ATOMIC_RELAXED);
}
}
}
@@ -1646,7 +1656,8 @@ delete_depth_big_v20(struct rte_lpm_v20 *lpm, uint32_t
ip_masked,
*/
for (i = tbl8_index; i < (tbl8_index + tbl8_range); i++) {
if (lpm->tbl8[i].depth <= depth)
- lpm->tbl8[i] = new_tbl8_entry;
+ __atomic_store(&lpm->tbl8[i], &new_tbl8_entry,
+ __ATOMIC_RELAXED);
}
}
@@ -1677,7 +1688,8 @@ delete_depth_big_v20(struct rte_lpm_v20 *lpm, uint32_t ip_masked,
/* Set tbl24 before freeing tbl8 to avoid race condition.
* Prevent the free of the tbl8 group from hoisting.
*/
- lpm->tbl24[tbl24_index] = new_tbl24_entry;
+ __atomic_store(&lpm->tbl24[tbl24_index], &new_tbl24_entry,
+ __ATOMIC_RELAXED);
__atomic_thread_fence(__ATOMIC_RELEASE);
tbl8_free_v20(lpm->tbl8, tbl8_group_start);
}
@@ -1730,7 +1742,8 @@ delete_depth_big_v1604(struct rte_lpm *lpm, uint32_t
ip_masked,
*/
for (i = tbl8_index; i < (tbl8_index + tbl8_range); i++) {
if (lpm->tbl8[i].depth <= depth)
- lpm->tbl8[i] = new_tbl8_entry;
+ __atomic_store(&lpm->tbl8[i], &new_tbl8_entry,
+ __ATOMIC_RELAXED);
}
}
@@ -1761,7 +1774,8 @@ delete_depth_big_v1604(struct rte_lpm *lpm, uint32_t ip_masked,
/* Set tbl24 before freeing tbl8 to avoid race condition.
* Prevent the free of the tbl8 group from hoisting.
*/
- lpm->tbl24[tbl24_index] = new_tbl24_entry;
+ __atomic_store(&lpm->tbl24[tbl24_index], &new_tbl24_entry,
+ __ATOMIC_RELAXED);
__atomic_thread_fence(__ATOMIC_RELEASE);
