netdev - [PATCH net] gve: fix dma sync bug where not all pages synced

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-next>] [day] [month] [year] [list]

Date:   Mon, 18 Nov 2019 14:36:30 -0800
From:   Adi Suresh <adisuresh@...gle.com>
To:     netdev@...r.kernel.org
Cc:     Adi Suresh <adisuresh@...gle.com>,
        Catherine Sullivan <csully@...gle.com>
Subject: [PATCH net] gve: fix dma sync bug where not all pages synced

The previous commit "Fixes DMA synchronization" had a bug where the
last page in the memory range could not be synced. This change fixes
the behavior so that all the required pages are synced.

Signed-off-by: Adi Suresh <adisuresh@...gle.com>
Reviewed-by: Catherine Sullivan <csully@...gle.com>
---
 drivers/net/ethernet/google/gve/gve_tx.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/google/gve/gve_tx.c b/drivers/net/ethernet/google/gve/gve_tx.c
index 0a9a7ee2a866..89271380bbfd 100644
--- a/drivers/net/ethernet/google/gve/gve_tx.c
+++ b/drivers/net/ethernet/google/gve/gve_tx.c
@@ -393,12 +393,12 @@ static void gve_tx_fill_seg_desc(union gve_tx_desc *seg_desc,
 static void gve_dma_sync_for_device(struct device *dev, dma_addr_t *page_buses,
 				    u64 iov_offset, u64 iov_len)
 {
-	dma_addr_t dma;
-	u64 addr;
+	u64 last_page = (iov_offset + iov_len - 1) / PAGE_SIZE;
+	u64 first_page = iov_offset / PAGE_SIZE;
+	u64 page;
 
-	for (addr = iov_offset; addr < iov_offset + iov_len;
-	     addr += PAGE_SIZE) {
-		dma = page_buses[addr / PAGE_SIZE];
+	for (page = first_page; page <= last_page; page++) {
+		dma_addr_t dma = page_buses[page];
 		dma_sync_single_for_device(dev, dma, PAGE_SIZE, DMA_TO_DEVICE);
 	}
 }
-- 
2.24.0.432.g9d3f5f5b63-goog