netdev - [PATCH 2/6] netdev: octeon_mgmt: Fix race condition freeing TX buffers.

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]

Date:	Wed,  5 May 2010 16:03:09 -0700
From:	David Daney <ddaney@...iumnetworks.com>
To:	netdev@...r.kernel.org
Cc:	linux-mips@...ux-mips.org, David Daney <ddaney@...iumnetworks.com>
Subject: [PATCH 2/6] netdev: octeon_mgmt: Fix race condition freeing TX buffers.

Under heavy load the TX cleanup tasklet and xmit threads would race
and try to free too many buffers.

Signed-off-by: David Daney <ddaney@...iumnetworks.com>
---
 drivers/net/octeon/octeon_mgmt.c |   11 +++++++++--
 1 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/net/octeon/octeon_mgmt.c b/drivers/net/octeon/octeon_mgmt.c
index bbbd737..b975a2f 100644
--- a/drivers/net/octeon/octeon_mgmt.c
+++ b/drivers/net/octeon/octeon_mgmt.c
@@ -189,12 +189,19 @@ static void octeon_mgmt_clean_tx_buffers(struct octeon_mgmt *p)
 
 	mix_orcnt.u64 = cvmx_read_csr(CVMX_MIXX_ORCNT(port));
 	while (mix_orcnt.s.orcnt) {
+		spin_lock_irqsave(&p->tx_list.lock, flags);
+
+		mix_orcnt.u64 = cvmx_read_csr(CVMX_MIXX_ORCNT(port));
+
+		if (mix_orcnt.s.orcnt == 0) {
+			spin_unlock_irqrestore(&p->tx_list.lock, flags);
+			break;
+		}
+
 		dma_sync_single_for_cpu(p->dev, p->tx_ring_handle,
 					ring_size_to_bytes(OCTEON_MGMT_TX_RING_SIZE),
 					DMA_BIDIRECTIONAL);
 
-		spin_lock_irqsave(&p->tx_list.lock, flags);
-
 		re.d64 = p->tx_ring[p->tx_next_clean];
 		p->tx_next_clean =
 			(p->tx_next_clean + 1) % OCTEON_MGMT_TX_RING_SIZE;
-- 
1.6.6.1

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html