From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Kirsher Subject: [net-2.6 PATCH 2/3] igb: prevent skb_over panic w/ mtu smaller than 1K Date: Fri, 30 Jan 2009 16:54:04 -0800 Message-ID: <20090131005404.1466.30069.stgit@lost.foo-projects.org> References: <20090131005340.1466.93281.stgit@lost.foo-projects.org> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, jeff@garzik.org, gospo@redhat.com, Alexander Duyck , Jeff Kirsher To: davem@davemloft.net Return-path: Received: from qmta10.westchester.pa.mail.comcast.net ([76.96.62.17]:57835 "EHLO QMTA10.westchester.pa.mail.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753285AbZAaAyZ (ORCPT ); Fri, 30 Jan 2009 19:54:25 -0500 In-Reply-To: <20090131005340.1466.93281.stgit@lost.foo-projects.org> Sender: netdev-owner@vger.kernel.org List-ID: From: Alexander Duyck A panic has been observed with frame sizes smaller than 1K. This has been root caused to the hardware spanning larger frames across multiple buffers and then reporting the original frame size in the first descriptor. To prevent this we can enable set the LPE bit which in turn will restrict packet sizes to those set in the RLPML register. Signed-off-by: Alexander Duyck Signed-off-by: Jeff Kirsher --- drivers/net/igb/igb_main.c | 8 ++++---- 1 files changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/net/igb/igb_main.c b/drivers/net/igb/igb_main.c index cc94412..a50db53 100644 --- a/drivers/net/igb/igb_main.c +++ b/drivers/net/igb/igb_main.c @@ -1834,11 +1834,11 @@ static void igb_setup_rctl(struct igb_adapter *adapter) rctl |= E1000_RCTL_SECRC; /* - * disable store bad packets, long packet enable, and clear size bits. + * disable store bad packets and clear size bits. */ - rctl &= ~(E1000_RCTL_SBP | E1000_RCTL_LPE | E1000_RCTL_SZ_256); + rctl &= ~(E1000_RCTL_SBP | E1000_RCTL_SZ_256); - if (adapter->netdev->mtu > ETH_DATA_LEN) + /* enable LPE when to prevent packets larger than max_frame_size */ rctl |= E1000_RCTL_LPE; /* Setup buffer sizes */ @@ -1864,7 +1864,7 @@ static void igb_setup_rctl(struct igb_adapter *adapter) */ /* allocations using alloc_page take too long for regular MTU * so only enable packet split for jumbo frames */ - if (rctl & E1000_RCTL_LPE) { + if (adapter->netdev->mtu > ETH_DATA_LEN) { adapter->rx_ps_hdr_size = IGB_RXBUFFER_128; srrctl |= adapter->rx_ps_hdr_size << E1000_SRRCTL_BSIZEHDRSIZE_SHIFT;