[v2] ath10k: fix memory leak in rx ring buffer allocation

Commit Message

Rakesh Pillai Aug. 2, 2017, 10:33 a.m. UTC

From: Rakesh Pillai <[e-mail]>

ath10k: fix memory leak in rx ring buffer allocation

The rx ring buffers are added to a hash table if
firmware support full rx reorder. If the full rx
reorder support flag is not set before allocating
the rx ring buffers, none of the buffers are added
to the hash table.

There is a race condition between rx ring refill and
rx buffer replenish from napi poll. The interrupts are
enabled in hif start, before the rx ring is refilled during init.
We replenish buffers from napi poll due to the interrupts which
get enabled after hif start. Hence before the entire rx ring is
refilled during the init, the napi poll replenishes a few buffers
in steps of 100 buffers per attempt. During this rx ring replenish
from napi poll, the rx reorder flag has not been set due to which
the replenished buffers are not added to the hash table

Set the rx full reorder support flag before we allocate
the rx ring buffer to avoid the memory leak.

Signed-off-by: Rakesh Pillai <[e-mail]>
---
 drivers/net/wireless/ath/ath10k/core.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

Comments

Kalle Valo Aug. 8, 2017, 11:07 a.m. UTC | #1

Rakesh Pillai <[e-mail]> wrote:

> The rx ring buffers are added to a hash table if
> firmware support full rx reorder. If the full rx
> reorder support flag is not set before allocating
> the rx ring buffers, none of the buffers are added
> to the hash table.
> 
> There is a race condition between rx ring refill and
> rx buffer replenish from napi poll. The interrupts are
> enabled in hif start, before the rx ring is refilled during init.
> We replenish buffers from napi poll due to the interrupts which
> get enabled after hif start. Hence before the entire rx ring is
> refilled during the init, the napi poll replenishes a few buffers
> in steps of 100 buffers per attempt. During this rx ring replenish
> from napi poll, the rx reorder flag has not been set due to which
> the replenished buffers are not added to the hash table
> 
> Set the rx full reorder support flag before we allocate
> the rx ring buffer to avoid the memory leak.
> 
> Signed-off-by: Rakesh Pillai <[e-mail]>
> Signed-off-by: Kalle Valo <[e-mail]>

Patch applied to ath-next branch of ath.git, thanks.

f35a7f91f66a ath10k: fix memory leak in rx ring buffer allocation

Patch

diff --git a/drivers/net/wireless/ath/ath10k/core.c b/drivers/net/wireless/ath/ath10k/core.c
index 6906bdd..10b3384 100644
--- a/drivers/net/wireless/ath/ath10k/core.c
+++ b/drivers/net/wireless/ath/ath10k/core.c
@@ -1886,6 +1886,12 @@  int ath10k_core_start(struct ath10k *ar, enum ath10k_firmware_mode mode,
 		goto err_wmi_detach;
 	}
 
+	/* If firmware indicates Full Rx Reorder support it must be used in a
+	 * slightly different manner. Let HTT code know.
+	 */
+	ar->htt.rx_ring.in_ord_rx = !!(test_bit(WMI_SERVICE_RX_FULL_REORDER,
+						ar->wmi.svc_map));
+
 	status = ath10k_htt_rx_alloc(&ar->htt);
 	if (status) {
 		ath10k_err(ar, "failed to alloc htt rx: %d\n", status);
@@ -1997,12 +2003,6 @@  int ath10k_core_start(struct ath10k *ar, enum ath10k_firmware_mode mode,
 		}
 	}
 
-	/* If firmware indicates Full Rx Reorder support it must be used in a
-	 * slightly different manner. Let HTT code know.
-	 */
-	ar->htt.rx_ring.in_ord_rx = !!(test_bit(WMI_SERVICE_RX_FULL_REORDER,
-						ar->wmi.svc_map));
-
 	status = ath10k_htt_rx_ring_refill(ar);
 	if (status) {
 		ath10k_err(ar, "failed to refill htt rx ring: %d\n", status);