From 254a49d5139a70828d652ef4faec40763993e403 Mon Sep 17 00:00:00 2001 From: Grygorii Strashko Date: Tue, 9 Aug 2016 15:09:44 +0300 Subject: [PATCH] drivers: net: cpsw: fix kmemleak false-positive reports for sk buffers Kmemleak reports following false positive memory leaks for each sk buffers allocated by CPSW (__netdev_alloc_skb_ip_align()) in cpsw_ndo_open() and cpsw_rx_handler(): unreferenced object 0xea915000 (size 2048): comm "systemd-network", pid 713, jiffies 4294938323 (age 102.180s) hex dump (first 32 bytes): 00 58 91 ea ff ff ff ff ff ff ff ff ff ff ff ff .X.............. ff ff ff ff ff ff fd 0f 00 00 00 00 00 00 00 00 ................ backtrace: [] __kmalloc_track_caller+0x1a4/0x230 [] __alloc_skb+0x68/0x16c [] __netdev_alloc_skb+0x40/0x104 [] cpsw_ndo_open+0x374/0x670 [ti_cpsw] [] __dev_open+0xb0/0x114 [] __dev_change_flags+0x9c/0x14c [] dev_change_flags+0x20/0x50 [] do_setlink+0x2cc/0x78c [] rtnl_setlink+0xcc/0x100 [] rtnetlink_rcv_msg+0x184/0x224 [] netlink_rcv_skb+0xa8/0xc4 [] rtnetlink_rcv+0x2c/0x34 [] netlink_unicast+0x16c/0x1f8 [] netlink_sendmsg+0x334/0x348 [] sock_sendmsg+0x1c/0x2c [] SyS_sendto+0xc0/0xe8 unreferenced object 0xec861780 (size 192): comm "softirq", pid 0, jiffies 4294938759 (age 109.540s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 b0 5a ed 00 00 00 00 00 00 00 00 ......Z......... backtrace: [] kmem_cache_alloc+0x190/0x208 [] __build_skb+0x30/0x98 [] __netdev_alloc_skb+0xb8/0x104 [] cpsw_rx_handler+0x68/0x1e4 [ti_cpsw] [] __cpdma_chan_free+0xa8/0xc4 [davinci_cpdma] [] __cpdma_chan_process+0x14c/0x16c [davinci_cpdma] [] cpdma_chan_process+0x44/0x5c [davinci_cpdma] [] cpsw_rx_poll+0x1c/0x9c [ti_cpsw] [] net_rx_action+0x1f0/0x2ec [] __do_softirq+0x134/0x258 [] do_softirq+0x68/0x70 [] __local_bh_enable_ip+0xd4/0xe8 [] _raw_spin_unlock_bh+0x30/0x34 [] igmp6_group_added+0x4c/0x1bc [] ipv6_dev_mc_inc+0x398/0x434 [] addrconf_dad_work+0x224/0x39c This happens because CPSW allocates SK buffers and then passes pointers on them in CPDMA where they stored in internal CPPI RAM (SRAM) which belongs to DEV MMIO space. Kmemleak does not scan IO memory and so reports memory leaks. Hence, mark allocated sk buffers as false positive explicitly. Cc: Catalin Marinas Signed-off-by: Grygorii Strashko Acked-by: Catalin Marinas Signed-off-by: David S. Miller --- drivers/net/ethernet/ti/cpsw.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c index c51f34693eae..f85d605e4560 100644 --- a/drivers/net/ethernet/ti/cpsw.c +++ b/drivers/net/ethernet/ti/cpsw.c @@ -734,6 +734,7 @@ static void cpsw_rx_handler(void *token, int len, int status) netif_receive_skb(skb); ndev->stats.rx_bytes += len; ndev->stats.rx_packets++; + kmemleak_not_leak(new_skb); } else { ndev->stats.rx_dropped++; new_skb = skb; @@ -1325,6 +1326,7 @@ static int cpsw_ndo_open(struct net_device *ndev) kfree_skb(skb); goto err_cleanup; } + kmemleak_not_leak(skb); } /* continue even if we didn't manage to submit all * receive descs -- 2.20.1