From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Kirsher Subject: [net-next 2/9] i40e: always return VEB stat strings Date: Tue, 22 May 2018 10:45:20 -0700 Message-ID: <20180522174527.19680-3-jeffrey.t.kirsher@intel.com> References: <20180522174527.19680-1-jeffrey.t.kirsher@intel.com> Cc: Jacob Keller , netdev@vger.kernel.org, nhorman@redhat.com, sassmann@redhat.com, jogreene@redhat.com, Jeff Kirsher To: davem@davemloft.net Return-path: Received: from mga05.intel.com ([192.55.52.43]:51947 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751788AbeEVRoB (ORCPT ); Tue, 22 May 2018 13:44:01 -0400 In-Reply-To: <20180522174527.19680-1-jeffrey.t.kirsher@intel.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Jacob Keller The ethtool API for obtaining device statistics is not intended to allow runtime changes in the number of statistics reported. It may *appear* this way, as there is an ability to request the number of stats using ethtool_get_set_count(). However, it is expected that this must always return the same value for invocations of the same device. If we don't satisfy this contract, and allow the number of stats to change during run time, we could cause invalid memory accesses or report the stat strings incorrectly. This is because the API for obtaining stats is to (1) get the size, (2) get the strings and finally (3) get the stats. Since these are each separate ethtool op commands, it is not possible to maintain consistency by holding the RTNL lock over the whole operation. This results in the potential for a race condition to occur where the size changed between any of the 3 calls. Avoid this issue by requiring that we always return the same value for a given device. We can check any values which remain constant for the life of the device, but must not report different sizes depending on runtime attributes. This patch specifically fixes the VEB statistics strings to always be reported. Other issues will be fixed in future patches. Signed-off-by: Jacob Keller Tested-by: Andrew Bowers Signed-off-by: Jeff Kirsher --- .../net/ethernet/intel/i40e/i40e_ethtool.c | 52 ++++++++----------- 1 file changed, 23 insertions(+), 29 deletions(-) diff --git a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c index 329e59eae4a1..de5dad7ff340 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c +++ b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c @@ -1661,15 +1661,10 @@ static int i40e_get_stats_count(struct net_device *netdev) struct i40e_vsi *vsi = np->vsi; struct i40e_pf *pf = vsi->back; - if (vsi == pf->vsi[pf->lan_vsi] && pf->hw.partition_id == 1) { - if (pf->lan_veb != I40E_NO_VEB && - pf->flags & I40E_FLAG_VEB_STATS_ENABLED) - return I40E_PF_STATS_LEN(netdev) + I40E_VEB_STATS_TOTAL; - else - return I40E_PF_STATS_LEN(netdev); - } else { + if (vsi == pf->vsi[pf->lan_vsi] && pf->hw.partition_id == 1) + return I40E_PF_STATS_LEN(netdev) + I40E_VEB_STATS_TOTAL; + else return I40E_VSI_STATS_LEN(netdev); - } } static int i40e_get_sset_count(struct net_device *netdev, int sset) @@ -1760,6 +1755,8 @@ static void i40e_get_ethtool_stats(struct net_device *netdev, data[i++] = veb->tc_stats.tc_rx_packets[j]; data[i++] = veb->tc_stats.tc_rx_bytes[j]; } + } else { + i += I40E_VEB_STATS_TOTAL; } for (j = 0; j < I40E_GLOBAL_STATS_LEN; j++) { p = (char *)pf + i40e_gstrings_stats[j].stat_offset; @@ -1816,27 +1813,24 @@ static void i40e_get_strings(struct net_device *netdev, u32 stringset, if (vsi != pf->vsi[pf->lan_vsi] || pf->hw.partition_id != 1) return; - if ((pf->lan_veb != I40E_NO_VEB) && - (pf->flags & I40E_FLAG_VEB_STATS_ENABLED)) { - for (i = 0; i < I40E_VEB_STATS_LEN; i++) { - snprintf(p, ETH_GSTRING_LEN, "veb.%s", - i40e_gstrings_veb_stats[i].stat_string); - p += ETH_GSTRING_LEN; - } - for (i = 0; i < I40E_MAX_TRAFFIC_CLASS; i++) { - snprintf(p, ETH_GSTRING_LEN, - "veb.tc_%d_tx_packets", i); - p += ETH_GSTRING_LEN; - snprintf(p, ETH_GSTRING_LEN, - "veb.tc_%d_tx_bytes", i); - p += ETH_GSTRING_LEN; - snprintf(p, ETH_GSTRING_LEN, - "veb.tc_%d_rx_packets", i); - p += ETH_GSTRING_LEN; - snprintf(p, ETH_GSTRING_LEN, - "veb.tc_%d_rx_bytes", i); - p += ETH_GSTRING_LEN; - } + for (i = 0; i < I40E_VEB_STATS_LEN; i++) { + snprintf(p, ETH_GSTRING_LEN, "veb.%s", + i40e_gstrings_veb_stats[i].stat_string); + p += ETH_GSTRING_LEN; + } + for (i = 0; i < I40E_MAX_TRAFFIC_CLASS; i++) { + snprintf(p, ETH_GSTRING_LEN, + "veb.tc_%u_tx_packets", i); + p += ETH_GSTRING_LEN; + snprintf(p, ETH_GSTRING_LEN, + "veb.tc_%u_tx_bytes", i); + p += ETH_GSTRING_LEN; + snprintf(p, ETH_GSTRING_LEN, + "veb.tc_%u_rx_packets", i); + p += ETH_GSTRING_LEN; + snprintf(p, ETH_GSTRING_LEN, + "veb.tc_%u_rx_bytes", i); + p += ETH_GSTRING_LEN; } for (i = 0; i < I40E_GLOBAL_STATS_LEN; i++) { snprintf(p, ETH_GSTRING_LEN, "port.%s", -- 2.17.0