This is a note to let you know that I've just added the patch titled i40e: fix the panic when running bpf in xdpdrv mode to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: i40e-fix-the-panic-when-running-bpf-in-xdpdrv-mode.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 4e39a072a6a0fc422ba7da5e4336bdc295d70211 Mon Sep 17 00:00:00 2001 From: Jason Xing <xingwanli@xxxxxxxxxxxx> Date: Wed, 14 Apr 2021 10:34:28 +0800 Subject: i40e: fix the panic when running bpf in xdpdrv mode From: Jason Xing <xingwanli@xxxxxxxxxxxx> commit 4e39a072a6a0fc422ba7da5e4336bdc295d70211 upstream. Fix this panic by adding more rules to calculate the value of @rss_size_max which could be used in allocating the queues when bpf is loaded, which, however, could cause the failure and then trigger the NULL pointer of vsi->rx_rings. Prio to this fix, the machine doesn't care about how many cpus are online and then allocates 256 queues on the machine with 32 cpus online actually. Once the load of bpf begins, the log will go like this "failed to get tracking for 256 queues for VSI 0 err -12" and this "setup of MAIN VSI failed". Thus, I attach the key information of the crash-log here. BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 RIP: 0010:i40e_xdp+0xdd/0x1b0 [i40e] Call Trace: [2160294.717292] ? i40e_reconfig_rss_queues+0x170/0x170 [i40e] [2160294.717666] dev_xdp_install+0x4f/0x70 [2160294.718036] dev_change_xdp_fd+0x11f/0x230 [2160294.718380] ? dev_disable_lro+0xe0/0xe0 [2160294.718705] do_setlink+0xac7/0xe70 [2160294.719035] ? __nla_parse+0xed/0x120 [2160294.719365] rtnl_newlink+0x73b/0x860 Fixes: 41c445ff0f48 ("i40e: main driver core") Co-developed-by: Shujin Li <lishujin@xxxxxxxxxxxx> Signed-off-by: Shujin Li <lishujin@xxxxxxxxxxxx> Signed-off-by: Jason Xing <xingwanli@xxxxxxxxxxxx> Reviewed-by: Jesse Brandeburg <jesse.brandeburg@xxxxxxxxx> Acked-by: Jesper Dangaard Brouer <brouer@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/intel/i40e/i40e_main.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/drivers/net/ethernet/intel/i40e/i40e_main.c +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c @@ -8504,6 +8504,7 @@ static int i40e_sw_init(struct i40e_pf * { int err = 0; int size; + u16 pow; pf->msg_enable = netif_msg_init(I40E_DEFAULT_MSG_ENABLE, (NETIF_MSG_DRV|NETIF_MSG_PROBE|NETIF_MSG_LINK)); @@ -8531,6 +8532,11 @@ static int i40e_sw_init(struct i40e_pf * pf->rss_table_size = pf->hw.func_caps.rss_table_size; pf->rss_size_max = min_t(int, pf->rss_size_max, pf->hw.func_caps.num_tx_qp); + + /* find the next higher power-of-2 of num cpus */ + pow = roundup_pow_of_two(num_online_cpus()); + pf->rss_size_max = min_t(int, pf->rss_size_max, pow); + if (pf->hw.func_caps.rss) { pf->flags |= I40E_FLAG_RSS_ENABLED; pf->alloc_rss_size = min_t(int, pf->rss_size_max, Patches currently in stable-queue which might be from xingwanli@xxxxxxxxxxxx are queue-4.9/i40e-fix-the-panic-when-running-bpf-in-xdpdrv-mode.patch