[PATCH 0/2] Safe tailq element removal in i40e driver

[PATCH 0/2] Safe tailq element removal in i40e driver

[Pablo de Lara]

i40e driver was removing elements when iterating tailq lists 
with TAILQ_FOREACH macro, which is not safe.
Instead, TAILQ_FOREACH_SAFE macro is used when removing/freeing
these elements, which is defined in DPDK if it is not already
defined (in FreeBSD).

Pablo de Lara (2):
  eal: add tailq safe iterator macro
  net/i40e: avoid unsafe tailq element removal

 drivers/net/i40e/i40e_ethdev.c            | 12 +++++++-----
 lib/librte_eal/common/include/rte_tailq.h | 11 +++++++++++
 2 files changed, 18 insertions(+), 5 deletions(-)

-- 
2.7.4

[PATCH 1/2] eal: add tailq safe iterator macro

[Pablo de Lara]

Removing/freeing elements elements within a TAILQ_FOREACH loop is not safe.
FreeBSD defines TAILQ_FOREACH_SAFE macro, which permits
these operations safely.
This patch defines this macro for Linux systems, where it is not defined.

Signed-off-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>
---
 lib/librte_eal/common/include/rte_tailq.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/lib/librte_eal/common/include/rte_tailq.h b/lib/librte_eal/common/include/rte_tailq.h
index 4a686e6..cc3c0f1 100644
--- a/lib/librte_eal/common/include/rte_tailq.h
+++ b/lib/librte_eal/common/include/rte_tailq.h
@@ -155,6 +155,14 @@ void __attribute__((constructor, used)) tailqinitfn_ ##t(void) \
 		rte_panic("Cannot initialize tailq: %s\n", t.name); \
 }
 
+/* This macro permits both remove and free var within the loop safely.*/
+#ifndef TAILQ_FOREACH_SAFE
+#define TAILQ_FOREACH_SAFE(var, head, field, tvar)		\
+	for ((var) = TAILQ_FIRST((head));			\
+	    (var) && ((tvar) = TAILQ_NEXT((var), field), 1);	\
+	    (var) = (tvar))
+#endif
+
 #ifdef __cplusplus
 }
 #endif
-- 
2.7.4

[PATCH 2/2] net/i40e: avoid unsafe tailq element removal

[Pablo de Lara]

i40e driver was removing elements when iterating tailq lists
with TAILQ_FOREACH macro, which is not safe.
Instead, TAILQ_FOREACH_SAFE macro is used when removing/freeing
these elements.

Fixes: 4861cde46116 ("i40e: new poll mode driver")
Fixes: 440499cf5376 ("net/i40e: support floating VEB")

Signed-off-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>
---
 drivers/net/i40e/i40e_ethdev.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/net/i40e/i40e_ethdev.c b/drivers/net/i40e/i40e_ethdev.c
index 84c86aa..11a5804 100644
--- a/drivers/net/i40e/i40e_ethdev.c
+++ b/drivers/net/i40e/i40e_ethdev.c
@@ -31,7 +31,6 @@
  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include <sys/queue.h>
 #include <stdio.h>
 #include <errno.h>
 #include <stdint.h>
@@ -51,6 +50,7 @@
 #include <rte_alarm.h>
 #include <rte_dev.h>
 #include <rte_eth_ctrl.h>
+#include <rte_tailq.h>
 
 #include "i40e_logs.h"
 #include "base/i40e_prototype.h"
@@ -4094,6 +4094,7 @@ i40e_vsi_release(struct i40e_vsi *vsi)
 	struct i40e_pf *pf;
 	struct i40e_hw *hw;
 	struct i40e_vsi_list *vsi_list;
+	void *temp;
 	int ret;
 	struct i40e_mac_filter *f;
 	uint16_t user_param = vsi->user_param;
@@ -4106,7 +4107,7 @@ i40e_vsi_release(struct i40e_vsi *vsi)
 
 	/* VSI has child to attach, release child first */
 	if (vsi->veb) {
-		TAILQ_FOREACH(vsi_list, &vsi->veb->head, list) {
+		TAILQ_FOREACH_SAFE(vsi_list, &vsi->veb->head, list, temp) {
 			if (i40e_vsi_release(vsi_list->vsi) != I40E_SUCCESS)
 				return -1;
 			TAILQ_REMOVE(&vsi->veb->head, vsi_list, list);
@@ -4115,7 +4116,7 @@ i40e_vsi_release(struct i40e_vsi *vsi)
 	}
 
 	if (vsi->floating_veb) {
-		TAILQ_FOREACH(vsi_list, &vsi->floating_veb->head, list) {
+		TAILQ_FOREACH_SAFE(vsi_list, &vsi->floating_veb->head, list, temp) {
 			if (i40e_vsi_release(vsi_list->vsi) != I40E_SUCCESS)
 				return -1;
 			TAILQ_REMOVE(&vsi->floating_veb->head, vsi_list, list);
@@ -4124,7 +4125,7 @@ i40e_vsi_release(struct i40e_vsi *vsi)
 
 	/* Remove all macvlan filters of the VSI */
 	i40e_vsi_remove_all_macvlan_filter(vsi);
-	TAILQ_FOREACH(f, &vsi->mac_list, next)
+	TAILQ_FOREACH_SAFE(f, &vsi->mac_list, next, temp)
 		rte_free(f);
 
 	if (vsi->type != I40E_VSI_MAIN &&
@@ -4682,6 +4683,7 @@ i40e_vsi_config_vlan_filter(struct i40e_vsi *vsi, bool on)
 {
 	int i, num;
 	struct i40e_mac_filter *f;
+	void *temp;
 	struct i40e_mac_filter_info *mac_filter;
 	enum rte_mac_filter_type desired_filter;
 	int ret = I40E_SUCCESS;
@@ -4706,7 +4708,7 @@ i40e_vsi_config_vlan_filter(struct i40e_vsi *vsi, bool on)
 	i = 0;
 
 	/* Remove all existing mac */
-	TAILQ_FOREACH(f, &vsi->mac_list, next) {
+	TAILQ_FOREACH_SAFE(f, &vsi->mac_list, next, temp) {
 		mac_filter[i] = f->mac_info;
 		ret = i40e_vsi_delete_mac(vsi, &f->mac_info.mac_addr);
 		if (ret) {
-- 
2.7.4

[PATCH v2 0/2] Safe tailq element removal in i40e driver

[Pablo de Lara]

i40e driver was removing elements when iterating tailq lists 
with TAILQ_FOREACH macro, which is not safe.
Instead, TAILQ_FOREACH_SAFE macro is used when removing/freeing
these elements, which is defined in DPDK if it is not already
defined (in FreeBSD).

Changes in v2:
- Modified second commit title

Pablo de Lara (2):
  eal: add tailq safe iterator macro
  net/i40e: fix unsafe tailq element removal

 drivers/net/i40e/i40e_ethdev.c            | 12 +++++++-----
 lib/librte_eal/common/include/rte_tailq.h |  8 ++++++++
 2 files changed, 15 insertions(+), 5 deletions(-)

-- 
2.7.4

[PATCH v2 1/2] eal: add tailq safe iterator macro

[Pablo de Lara]

Removing/freeing elements elements within a TAILQ_FOREACH loop is not safe.
FreeBSD defines TAILQ_FOREACH_SAFE macro, which permits
these operations safely.
This patch defines this macro for Linux systems, where it is not defined.

Signed-off-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>
---
 lib/librte_eal/common/include/rte_tailq.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/lib/librte_eal/common/include/rte_tailq.h b/lib/librte_eal/common/include/rte_tailq.h
index 4a686e6..cc3c0f1 100644
--- a/lib/librte_eal/common/include/rte_tailq.h
+++ b/lib/librte_eal/common/include/rte_tailq.h
@@ -155,6 +155,14 @@ void __attribute__((constructor, used)) tailqinitfn_ ##t(void) \
 		rte_panic("Cannot initialize tailq: %s\n", t.name); \
 }
 
+/* This macro permits both remove and free var within the loop safely.*/
+#ifndef TAILQ_FOREACH_SAFE
+#define TAILQ_FOREACH_SAFE(var, head, field, tvar)		\
+	for ((var) = TAILQ_FIRST((head));			\
+	    (var) && ((tvar) = TAILQ_NEXT((var), field), 1);	\
+	    (var) = (tvar))
+#endif
+
 #ifdef __cplusplus
 }
 #endif
-- 
2.7.4

[PATCH v2 2/2] net/i40e: fix unsafe tailq element removal

[Pablo de Lara]

i40e driver was removing elements when iterating tailq lists
with TAILQ_FOREACH macro, which is not safe.
Instead, TAILQ_FOREACH_SAFE macro is used when removing/freeing
these elements.

Fixes: 4861cde46116 ("i40e: new poll mode driver")
Fixes: 440499cf5376 ("net/i40e: support floating VEB")

Signed-off-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>
---
 drivers/net/i40e/i40e_ethdev.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/net/i40e/i40e_ethdev.c b/drivers/net/i40e/i40e_ethdev.c
index 84c86aa..11a5804 100644
--- a/drivers/net/i40e/i40e_ethdev.c
+++ b/drivers/net/i40e/i40e_ethdev.c
@@ -31,7 +31,6 @@
  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include <sys/queue.h>
 #include <stdio.h>
 #include <errno.h>
 #include <stdint.h>
@@ -51,6 +50,7 @@
 #include <rte_alarm.h>
 #include <rte_dev.h>
 #include <rte_eth_ctrl.h>
+#include <rte_tailq.h>
 
 #include "i40e_logs.h"
 #include "base/i40e_prototype.h"
@@ -4094,6 +4094,7 @@ i40e_vsi_release(struct i40e_vsi *vsi)
 	struct i40e_pf *pf;
 	struct i40e_hw *hw;
 	struct i40e_vsi_list *vsi_list;
+	void *temp;
 	int ret;
 	struct i40e_mac_filter *f;
 	uint16_t user_param = vsi->user_param;
@@ -4106,7 +4107,7 @@ i40e_vsi_release(struct i40e_vsi *vsi)
 
 	/* VSI has child to attach, release child first */
 	if (vsi->veb) {
-		TAILQ_FOREACH(vsi_list, &vsi->veb->head, list) {
+		TAILQ_FOREACH_SAFE(vsi_list, &vsi->veb->head, list, temp) {
 			if (i40e_vsi_release(vsi_list->vsi) != I40E_SUCCESS)
 				return -1;
 			TAILQ_REMOVE(&vsi->veb->head, vsi_list, list);
@@ -4115,7 +4116,7 @@ i40e_vsi_release(struct i40e_vsi *vsi)
 	}
 
 	if (vsi->floating_veb) {
-		TAILQ_FOREACH(vsi_list, &vsi->floating_veb->head, list) {
+		TAILQ_FOREACH_SAFE(vsi_list, &vsi->floating_veb->head, list, temp) {
 			if (i40e_vsi_release(vsi_list->vsi) != I40E_SUCCESS)
 				return -1;
 			TAILQ_REMOVE(&vsi->floating_veb->head, vsi_list, list);
@@ -4124,7 +4125,7 @@ i40e_vsi_release(struct i40e_vsi *vsi)
 
 	/* Remove all macvlan filters of the VSI */
 	i40e_vsi_remove_all_macvlan_filter(vsi);
-	TAILQ_FOREACH(f, &vsi->mac_list, next)
+	TAILQ_FOREACH_SAFE(f, &vsi->mac_list, next, temp)
 		rte_free(f);
 
 	if (vsi->type != I40E_VSI_MAIN &&
@@ -4682,6 +4683,7 @@ i40e_vsi_config_vlan_filter(struct i40e_vsi *vsi, bool on)
 {
 	int i, num;
 	struct i40e_mac_filter *f;
+	void *temp;
 	struct i40e_mac_filter_info *mac_filter;
 	enum rte_mac_filter_type desired_filter;
 	int ret = I40E_SUCCESS;
@@ -4706,7 +4708,7 @@ i40e_vsi_config_vlan_filter(struct i40e_vsi *vsi, bool on)
 	i = 0;
 
 	/* Remove all existing mac */
-	TAILQ_FOREACH(f, &vsi->mac_list, next) {
+	TAILQ_FOREACH_SAFE(f, &vsi->mac_list, next, temp) {
 		mac_filter[i] = f->mac_info;
 		ret = i40e_vsi_delete_mac(vsi, &f->mac_info.mac_addr);
 		if (ret) {
-- 
2.7.4

Re: [PATCH v2 2/2] net/i40e: fix unsafe tailq element removal

[Thomas Monjalon]

2016-07-22 15:02, Pablo de Lara:
> i40e driver was removing elements when iterating tailq lists
> with TAILQ_FOREACH macro, which is not safe.
> Instead, TAILQ_FOREACH_SAFE macro is used when removing/freeing
> these elements.

Pablo,
Maybe we should add a note to explain that the bug of freeing
while iterating is seen since the memory is zeroed on free:
	ea0bddbd14e6 ("mem: zero out memory on free")

Re: [PATCH v2 0/2] Safe tailq element removal in i40e driver

[Thomas Monjalon]

2016-07-22 15:02, Pablo de Lara:
> i40e driver was removing elements when iterating tailq lists 
> with TAILQ_FOREACH macro, which is not safe.
> Instead, TAILQ_FOREACH_SAFE macro is used when removing/freeing
> these elements, which is defined in DPDK if it is not already
> defined (in FreeBSD).

Applied, thanks