linux-kernel - [PATCH 4.19 34/57] ibmvnic: Unmap DMA address of TX descriptor buffers after use

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20190908121140.554764096@linuxfoundation.org>
Date:   Sun,  8 Sep 2019 13:41:58 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Abdul Haleem <abdhalee@...ux.vnet.ibm.com>,
        "Devesh K. Singh" <devesh_singh@...ibm.com>,
        Thomas Falcon <tlfalcon@...ux.ibm.com>,
        "David S. Miller" <davem@...emloft.net>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.19 34/57] ibmvnic: Unmap DMA address of TX descriptor buffers after use

[ Upstream commit 80f0fe0934cd3daa13a5e4d48a103f469115b160 ]

There's no need to wait until a completion is received to unmap
TX descriptor buffers that have been passed to the hypervisor.
Instead unmap it when the hypervisor call has completed. This patch
avoids the possibility that a buffer will not be unmapped because
a TX completion is lost or mishandled.

Reported-by: Abdul Haleem <abdhalee@...ux.vnet.ibm.com>
Tested-by: Devesh K. Singh <devesh_singh@...ibm.com>
Signed-off-by: Thomas Falcon <tlfalcon@...ux.ibm.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/net/ethernet/ibm/ibmvnic.c | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index 0ae43d27cdcff..255de7d68cd33 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -1586,6 +1586,8 @@ static int ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev)
 		lpar_rc = send_subcrq_indirect(adapter, handle_array[queue_num],
 					       (u64)tx_buff->indir_dma,
 					       (u64)num_entries);
+		dma_unmap_single(dev, tx_buff->indir_dma,
+				 sizeof(tx_buff->indir_arr), DMA_TO_DEVICE);
 	} else {
 		tx_buff->num_entries = num_entries;
 		lpar_rc = send_subcrq(adapter, handle_array[queue_num],
@@ -2747,7 +2749,6 @@ static int ibmvnic_complete_tx(struct ibmvnic_adapter *adapter,
 	union sub_crq *next;
 	int index;
 	int i, j;
-	u8 *first;
 
 restart_loop:
 	while (pending_scrq(adapter, scrq)) {
@@ -2777,14 +2778,6 @@ restart_loop:
 
 				txbuff->data_dma[j] = 0;
 			}
-			/* if sub_crq was sent indirectly */
-			first = &txbuff->indir_arr[0].generic.first;
-			if (*first == IBMVNIC_CRQ_CMD) {
-				dma_unmap_single(dev, txbuff->indir_dma,
-						 sizeof(txbuff->indir_arr),
-						 DMA_TO_DEVICE);
-				*first = 0;
-			}
 
 			if (txbuff->last_frag) {
 				dev_kfree_skb_any(txbuff->skb);
-- 
2.20.1