diff mbox series

[net-next,10/11] i40e: free the skb after clearing the bitlock

Message ID 20180514152747.23154-11-jeffrey.t.kirsher@intel.com
State Accepted, archived
Delegated to: David Miller
Headers show
Series 40GbE Intel Wired LAN Driver Updates 2018-05-14 | expand

Commit Message

Kirsher, Jeffrey T May 14, 2018, 3:27 p.m. UTC 
From: Jacob Keller <jacob.e.keller@intel.com>

In commit bbc4e7d273b5 ("i40e: fix race condition with PTP_TX_IN_PROGRESS
bits") we modified the code which handles Tx timestamps so that we would
clear the progress bit as soon as possible.

A later commit 0bc0706b46cd ("i40e: check for Tx timestamp timeouts during
watchdog") introduced similar code for detecting and handling cleanup of
a blocked Tx timestamp. This code did not use the same pattern for cleaning
up the skb.

Update this code to wait to free the skb until after the bit lock is
free, by first setting the ptp_tx_skb to NULL and clearing the lock.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
---
 drivers/net/ethernet/intel/i40e/i40e_ptp.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/intel/i40e/i40e_ptp.c b/drivers/net/ethernet/intel/i40e/i40e_ptp.c
index 6706141a5ccd..d50d84927e6b 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_ptp.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_ptp.c
@@ -321,6 +321,8 @@  void i40e_ptp_rx_hang(struct i40e_pf *pf)
  **/
 void i40e_ptp_tx_hang(struct i40e_pf *pf)
 {
+	struct sk_buff *skb;
+
 	if (!(pf->flags & I40E_FLAG_PTP) || !pf->ptp_tx)
 		return;
 
@@ -333,9 +335,12 @@  void i40e_ptp_tx_hang(struct i40e_pf *pf)
 	 * within a second it is reasonable to assume that we never will.
 	 */
 	if (time_is_before_jiffies(pf->ptp_tx_start + HZ)) {
-		dev_kfree_skb_any(pf->ptp_tx_skb);
+		skb = pf->ptp_tx_skb;
 		pf->ptp_tx_skb = NULL;
 		clear_bit_unlock(__I40E_PTP_TX_IN_PROGRESS, pf->state);
+
+		/* Free the skb after we clear the bitlock */
+		dev_kfree_skb_any(skb);
 		pf->tx_hwtstamp_timeouts++;
 	}
 }