[PATCH v1] lib/distributor: fix segfaults in flush

[PATCH v1] lib/distributor: fix segfaults in flush

[David Hunt]

A segfault when flushing packets has been revealed by further testing
when using distributor in single packet mode. This patch resolves that.

Fixes: 775003ad2f96 ("distributor: add new burst-capable library")

Reported-by: Yong Liu <yong.liu@intel.com>
Signed-off-by: David Hunt <david.hunt@intel.com>
---
 lib/librte_distributor/rte_distributor.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/librte_distributor/rte_distributor.c b/lib/librte_distributor/rte_distributor.c
index 4725904..e4dfa7f 100644
--- a/lib/librte_distributor/rte_distributor.c
+++ b/lib/librte_distributor/rte_distributor.c
@@ -555,7 +555,7 @@ total_outstanding(const struct rte_distributor *d)
 int
 rte_distributor_flush_v1705(struct rte_distributor *d)
 {
-	const unsigned int flushed = total_outstanding(d);
+	unsigned int flushed;
 	unsigned int wkr;
 
 	if (d->alg_type == RTE_DIST_ALG_SINGLE) {
@@ -563,6 +563,8 @@ rte_distributor_flush_v1705(struct rte_distributor *d)
 		return rte_distributor_flush_v20(d->d_v20);
 	}
 
+	flushed = total_outstanding(d);
+
 	while (total_outstanding(d) > 0)
 		rte_distributor_process(d, NULL, 0);
 
@@ -590,6 +592,7 @@ rte_distributor_clear_returns_v1705(struct rte_distributor *d)
 	if (d->alg_type == RTE_DIST_ALG_SINGLE) {
 		/* Call the old API */
 		rte_distributor_clear_returns_v20(d->d_v20);
+		return;
 	}
 
 	/* throw away returns, so workers can exit */
-- 
2.7.4

Re: [PATCH v1] lib/distributor: fix segfaults in flush

[Liu, Yong]

> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of David Hunt
> Sent: Thursday, April 13, 2017 4:36 PM
> To: dev@dpdk.org
> Cc: Hunt, David <david.hunt@intel.com>
> Subject: [dpdk-dev] [PATCH v1] lib/distributor: fix segfaults in flush
> 
> A segfault when flushing packets has been revealed by further testing
> when using distributor in single packet mode. This patch resolves that.
> 
> Fixes: 775003ad2f96 ("distributor: add new burst-capable library")
> 
> Reported-by: Yong Liu <yong.liu@intel.com>
> Signed-off-by: David Hunt <david.hunt@intel.com>
> ---

Tested-by: Yong Liu <yong.liu@intel.com>	

Re: [PATCH v1] lib/distributor: fix segfaults in flush

[Bruce Richardson]

On Thu, Apr 13, 2017 at 09:36:27AM +0100, David Hunt wrote:
> A segfault when flushing packets has been revealed by further testing
> when using distributor in single packet mode. This patch resolves that.
> 
> Fixes: 775003ad2f96 ("distributor: add new burst-capable library")
> 
> Reported-by: Yong Liu <yong.liu@intel.com>
> Signed-off-by: David Hunt <david.hunt@intel.com>

Hi Dave,

I think you could do with giving more details in the commit messaage on
how/why the error occurs and how exactly this patch fixes it.

With expanded commit log message:
Acked-by: Bruce Richardson <bruce.richardson@intel.com>

[PATCH v2] lib/distributor: fix segfaults in flush

[David Hunt]

Occasionally, the distributor single-packet-at-a-time mode will
segfault because it inadvertently calls some burst mode code when
flushing packets.

This patch ensures that only the v20 (single mode) codepath is used, and
returns without falling through to the burst mode code.

Fixes: 775003ad2f96 ("distributor: add new burst-capable library")

v2: Extented commit message. Patch remains the same.

Signed-off-by: David Hunt <david.hunt@intel.com>
Tested-by: Yong Liu <yong.liu@intel.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
---
 lib/librte_distributor/rte_distributor.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/librte_distributor/rte_distributor.c b/lib/librte_distributor/rte_distributor.c
index 4725904..e4dfa7f 100644
--- a/lib/librte_distributor/rte_distributor.c
+++ b/lib/librte_distributor/rte_distributor.c
@@ -555,7 +555,7 @@ total_outstanding(const struct rte_distributor *d)
 int
 rte_distributor_flush_v1705(struct rte_distributor *d)
 {
-	const unsigned int flushed = total_outstanding(d);
+	unsigned int flushed;
 	unsigned int wkr;
 
 	if (d->alg_type == RTE_DIST_ALG_SINGLE) {
@@ -563,6 +563,8 @@ rte_distributor_flush_v1705(struct rte_distributor *d)
 		return rte_distributor_flush_v20(d->d_v20);
 	}
 
+	flushed = total_outstanding(d);
+
 	while (total_outstanding(d) > 0)
 		rte_distributor_process(d, NULL, 0);
 
@@ -590,6 +592,7 @@ rte_distributor_clear_returns_v1705(struct rte_distributor *d)
 	if (d->alg_type == RTE_DIST_ALG_SINGLE) {
 		/* Call the old API */
 		rte_distributor_clear_returns_v20(d->d_v20);
+		return;
 	}
 
 	/* throw away returns, so workers can exit */
-- 
2.7.4

Re: [PATCH v2] lib/distributor: fix segfaults in flush

[Thomas Monjalon]

14/04/2017 10:59, David Hunt:
> Occasionally, the distributor single-packet-at-a-time mode will
> segfault because it inadvertently calls some burst mode code when
> flushing packets.
> 
> This patch ensures that only the v20 (single mode) codepath is used, and
> returns without falling through to the burst mode code.
> 
> Fixes: 775003ad2f96 ("distributor: add new burst-capable library")
> 
> v2: Extented commit message. Patch remains the same.
> 
> Signed-off-by: David Hunt <david.hunt@intel.com>
> Tested-by: Yong Liu <yong.liu@intel.com>
> Acked-by: Bruce Richardson <bruce.richardson@intel.com>

Applied, thanks