[02/29] net/ena/base: make allocation macros thread-safe

Message ID 20200327101823.12646-3-mk@semihalf.com (mailing list archive)
State Superseded, archived
Delegated to: Andrew Rybchenko
Headers
Series Update ENA driver to v2.1.0 |

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/Intel-compilation fail Compilation issues

Commit Message

Michal Krawczyk March 27, 2020, 10:17 a.m. UTC
  From: Igor Chauskin <igorch@amazon.com>

Memory allocation region id could possibly be non-unique
due to non-atomic increment, causing allocation failure.

Fixes: 9ba7981ec992 ("ena: add communication layer for DPDK")
Cc: stable@dpdk.org

Signed-off-by: Igor Chauskin <igorch@amazon.com>
Reviewed-by: Michal Krawczyk <mk@semihalf.com>
Reviewed-by: Guy Tzalik <gtzalik@amazon.com>
---
 drivers/net/ena/base/ena_plat_dpdk.h | 8 +++++---
 drivers/net/ena/ena_ethdev.c         | 2 +-
 2 files changed, 6 insertions(+), 4 deletions(-)
  

Comments

Stephen Hemminger March 27, 2020, 2:54 p.m. UTC | #1
On Fri, 27 Mar 2020 11:17:56 +0100
Michal Krawczyk <mk@semihalf.com> wrote:

> From: Igor Chauskin <igorch@amazon.com>
> 
> Memory allocation region id could possibly be non-unique
> due to non-atomic increment, causing allocation failure.
> 
> Fixes: 9ba7981ec992 ("ena: add communication layer for DPDK")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Igor Chauskin <igorch@amazon.com>
> Reviewed-by: Michal Krawczyk <mk@semihalf.com>
> Reviewed-by: Guy Tzalik <gtzalik@amazon.com>

With DPDK all control operations are the device are supposed
to be single threaded by the caller. Do you have an allocation in
some datapath?
  
Michal Krawczyk March 31, 2020, 9:47 a.m. UTC | #2
pt., 27 mar 2020 o 15:54 Stephen Hemminger
<stephen@networkplumber.org> napisał(a):
>
> On Fri, 27 Mar 2020 11:17:56 +0100
> Michal Krawczyk <mk@semihalf.com> wrote:
>
> > From: Igor Chauskin <igorch@amazon.com>
> >
> > Memory allocation region id could possibly be non-unique
> > due to non-atomic increment, causing allocation failure.
> >
> > Fixes: 9ba7981ec992 ("ena: add communication layer for DPDK")
> > Cc: stable@dpdk.org
> >
> > Signed-off-by: Igor Chauskin <igorch@amazon.com>
> > Reviewed-by: Michal Krawczyk <mk@semihalf.com>
> > Reviewed-by: Guy Tzalik <gtzalik@amazon.com>
>
> With DPDK all control operations are the device are supposed
> to be single threaded by the caller. Do you have an allocation in
> some datapath?

Currently, there aren't any allocations on the datapath. But if you
don't mind, we would like to keep the atomics there for future
robustness.
  

Patch

diff --git a/drivers/net/ena/base/ena_plat_dpdk.h b/drivers/net/ena/base/ena_plat_dpdk.h
index b611fb204b..192bbaefcf 100644
--- a/drivers/net/ena/base/ena_plat_dpdk.h
+++ b/drivers/net/ena/base/ena_plat_dpdk.h
@@ -180,7 +180,7 @@  do {                                                                   \
  * Each rte_memzone should have unique name.
  * To satisfy it, count number of allocations and add it to name.
  */
-extern uint32_t ena_alloc_cnt;
+extern rte_atomic32_t ena_alloc_cnt;
 
 #define ENA_MEM_ALLOC_COHERENT(dmadev, size, virt, phys, handle)	\
 	do {								\
@@ -188,7 +188,8 @@  extern uint32_t ena_alloc_cnt;
 		char z_name[RTE_MEMZONE_NAMESIZE];			\
 		ENA_TOUCH(dmadev); ENA_TOUCH(handle);			\
 		snprintf(z_name, sizeof(z_name),			\
-				"ena_alloc_%d", ena_alloc_cnt++);	\
+			 "ena_alloc_%d",				\
+			 rte_atomic32_add_return(&ena_alloc_cnt, 1));	\
 		mz = rte_memzone_reserve(z_name, size, SOCKET_ID_ANY,	\
 				RTE_MEMZONE_IOVA_CONTIG);		\
 		handle = mz;						\
@@ -213,7 +214,8 @@  extern uint32_t ena_alloc_cnt;
 		char z_name[RTE_MEMZONE_NAMESIZE];			\
 		ENA_TOUCH(dmadev); ENA_TOUCH(dev_node);			\
 		snprintf(z_name, sizeof(z_name),			\
-				"ena_alloc_%d", ena_alloc_cnt++);	\
+			 "ena_alloc_%d",				\
+			 rte_atomic32_add_return(&ena_alloc_cnt, 1));	\
 		mz = rte_memzone_reserve(z_name, size, node,		\
 				RTE_MEMZONE_IOVA_CONTIG);		\
 		mem_handle = mz;					\
diff --git a/drivers/net/ena/ena_ethdev.c b/drivers/net/ena/ena_ethdev.c
index a8f8784a9f..cab38152a7 100644
--- a/drivers/net/ena/ena_ethdev.c
+++ b/drivers/net/ena/ena_ethdev.c
@@ -89,7 +89,7 @@  struct ena_stats {
  * Each rte_memzone should have unique name.
  * To satisfy it, count number of allocation and add it to name.
  */
-uint32_t ena_alloc_cnt;
+rte_atomic32_t ena_alloc_cnt;
 
 static const struct ena_stats ena_stats_global_strings[] = {
 	ENA_STAT_GLOBAL_ENTRY(wd_expired),