Hi Ruifeng,
On 18/07/2020 10:22, Ruifeng Wang wrote:
-----Original Message-----
From: Medvedkin, Vladimir <vladimir.medved...@intel.com>
Sent: Saturday, July 18, 2020 1:12 AM
To: Ruifeng Wang <ruifeng.w...@arm.com>; Bruce Richardson
<bruce.richard...@intel.com>
Cc: dev@dpdk.org; nd <n...@arm.com>; Honnappa Nagarahalli
<honnappa.nagaraha...@arm.com>; Phil Yang <phil.y...@arm.com>
Subject: Re: [PATCH v2] lpm: fix unchecked return value
Hi Ruifeng,
Hi Vladimir,
On 16/07/2020 16:49, Ruifeng Wang wrote:
Coverity complains about unchecked return value of
rte_rcu_qsbr_dq_enqueue.
By default, defer queue size is big enough to hold all tbl8 groups.
When enqueue fails, return error to the user to indicate system issue.
Coverity issue: 360832
Fixes: 8a9f8564e9f9 ("lpm: implement RCU rule reclamation")
Signed-off-by: Ruifeng Wang <ruifeng.w...@arm.com>
---
v2:
Converted return value to conform to LPM API convention. (Vladimir)
lib/librte_lpm/rte_lpm.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)
diff --git a/lib/librte_lpm/rte_lpm.c b/lib/librte_lpm/rte_lpm.c index
2db9e16a2..757436f49 100644
--- a/lib/librte_lpm/rte_lpm.c
+++ b/lib/librte_lpm/rte_lpm.c
@@ -532,11 +532,12 @@ tbl8_alloc(struct rte_lpm *lpm)
return group_idx;
}
-static void
+static int32_t
tbl8_free(struct rte_lpm *lpm, uint32_t tbl8_group_start)
{
struct rte_lpm_tbl_entry zero_tbl8_entry = {0};
struct __rte_lpm *internal_lpm;
+ int status;
internal_lpm = container_of(lpm, struct __rte_lpm, lpm);
if (internal_lpm->v == NULL) {
@@ -552,9 +553,15 @@ tbl8_free(struct rte_lpm *lpm, uint32_t
tbl8_group_start)
__ATOMIC_RELAXED);
} else if (internal_lpm->rcu_mode == RTE_LPM_QSBR_MODE_DQ) {
/* Push into QSBR defer queue. */
- rte_rcu_qsbr_dq_enqueue(internal_lpm->dq,
+ status = rte_rcu_qsbr_dq_enqueue(internal_lpm->dq,
(void *)&tbl8_group_start);
+ if (status == 1) {
+ RTE_LOG(ERR, LPM, "Failed to push QSBR FIFO\n");
+ return -rte_errno;
+ }
}
+
+ return 0;
}
static __rte_noinline int32_t
@@ -1040,7 +1047,7 @@ delete_depth_big(struct rte_lpm *lpm, uint32_t
ip_masked,
#define group_idx next_hop
uint32_t tbl24_index, tbl8_group_index, tbl8_group_start,
tbl8_index,
tbl8_range, i;
- int32_t tbl8_recycle_index;
+ int32_t tbl8_recycle_index, status = 0;
/*
* Calculate the index into tbl24 and range. Note: All depths
larger @@ -1097,7 +1104,7 @@ delete_depth_big(struct rte_lpm *lpm,
uint32_t ip_masked,
*/
lpm->tbl24[tbl24_index].valid = 0;
__atomic_thread_fence(__ATOMIC_RELEASE);
- tbl8_free(lpm, tbl8_group_start);
+ status = tbl8_free(lpm, tbl8_group_start);
} else if (tbl8_recycle_index > -1) {
/* Update tbl24 entry. */
struct rte_lpm_tbl_entry new_tbl24_entry = { @@ -1113,10
+1120,10
@@ delete_depth_big(struct rte_lpm *lpm, uint32_t ip_masked,
__atomic_store(&lpm->tbl24[tbl24_index],
&new_tbl24_entry,
__ATOMIC_RELAXED);
__atomic_thread_fence(__ATOMIC_RELEASE);
- tbl8_free(lpm, tbl8_group_start);
+ status = tbl8_free(lpm, tbl8_group_start);
}
#undef group_idx
- return 0;
+ return status;
This will change rte_lpm_delete API. As a suggestion, you can leave it as it
was before ("return 0"), and send separate patch (with "return status)"
which will be targeted to 20.11.
Is the change of API because a variable is returned instead of constant?
The patch passed ABI check on Travis:
http://mails.dpdk.org/archives/test-report/2020-July/144864.html
So I didn't know there is API/ABI issue.
Because new error status codes are returned. At the moment
rte_lpm_delete() returns only -EINVAL. After patches it will also
returns -ENOSPC. The user's code may not handle this returned error status.
On the other hand, from documentation about returned value:
"0 on success, negative value otherwise",
and given the fact that this behavior is only after calling
rte_lpm_rcu_qsbr_add(), I think we can accept this patch.
Bruce, please correct me.
Thanks.
/Ruifeng
}
/*
--
Regards,
Vladimir
Acked-by: Vladimir Medvedkin <vladimir.medved...@intel.com>
--
Regards,
Vladimir
