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authorLarry Finger <Larry.Finger@lwfinger.net>2015-03-21 23:16:05 +0300
committerKalle Valo <kvalo@codeaurora.org>2015-03-22 08:52:25 +0300
commitbe0b5e635883678bfbc695889772fed545f3427d (patch)
tree7d43fedefa36a0a82bbdb68874872190e861d5da
parentf93a25b38cbd840f26c9fd2dd8a6611a57b259b7 (diff)
downloadlinux-be0b5e635883678bfbc695889772fed545f3427d.tar.xz
rtlwifi: Fix IOMMU mapping leak in AP mode
Transmission of an AP beacon does not call the TX interrupt service routine, which usually does the cleanup. Instead, cleanup is handled in a tasklet completion routine. Unfortunately, this routine has a serious bug in that it does not release the DMA mapping before it frees the skb, thus one IOMMU mapping is leaked for each beacon. The test system failed with no free IOMMU mapping slots approximately one hour after hostapd was used to start an AP. This issue was reported and tested at https://github.com/lwfinger/rtlwifi_new/issues/30. Reported-and-tested-by: Kevin Mullican <kevin@mullican.com> Cc: Kevin Mullican <kevin@mullican.com> Signed-off-by: Shao Fu <shaofu@realtek.com> Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net> Cc: Stable <stable@vger.kernel.org> [3.18+] Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
-rw-r--r--drivers/net/wireless/rtlwifi/pci.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/drivers/net/wireless/rtlwifi/pci.c b/drivers/net/wireless/rtlwifi/pci.c
index a62170ea0481..8c45cf44ce24 100644
--- a/drivers/net/wireless/rtlwifi/pci.c
+++ b/drivers/net/wireless/rtlwifi/pci.c
@@ -1124,12 +1124,22 @@ static void _rtl_pci_prepare_bcn_tasklet(struct ieee80211_hw *hw)
/*This is for new trx flow*/
struct rtl_tx_buffer_desc *pbuffer_desc = NULL;
u8 temp_one = 1;
+ u8 *entry;
memset(&tcb_desc, 0, sizeof(struct rtl_tcb_desc));
ring = &rtlpci->tx_ring[BEACON_QUEUE];
pskb = __skb_dequeue(&ring->queue);
- if (pskb)
+ if (rtlpriv->use_new_trx_flow)
+ entry = (u8 *)(&ring->buffer_desc[ring->idx]);
+ else
+ entry = (u8 *)(&ring->desc[ring->idx]);
+ if (pskb) {
+ pci_unmap_single(rtlpci->pdev,
+ rtlpriv->cfg->ops->get_desc(
+ (u8 *)entry, true, HW_DESC_TXBUFF_ADDR),
+ pskb->len, PCI_DMA_TODEVICE);
kfree_skb(pskb);
+ }
/*NB: the beacon data buffer must be 32-bit aligned. */
pskb = ieee80211_beacon_get(hw, mac->vif);