From: Jason Xing xingwanli@kuaishou.com
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@kuaishou.com Signed-off-by: Shujin Li lishujin@kuaishou.com Signed-off-by: Jason Xing xingwanli@kuaishou.com Reviewed-by: Jesse Brandeburg jesse.brandeburg@intel.com Acked-by: Jesper Dangaard Brouer brouer@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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 @@ -11863,6 +11863,7 @@ static int i40e_sw_init(struct i40e_pf * { int err = 0; int size; + u16 pow;
/* Set default capability flags */ pf->flags = I40E_FLAG_RX_CSUM_ENABLED | @@ -11881,6 +11882,11 @@ 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,