]> git.baikalelectronics.ru Git - kernel.git/commit
drivers: net: cpsw: fix kmemleak false-positive reports for sk buffers
authorGrygorii Strashko <grygorii.strashko@ti.com>
Tue, 9 Aug 2016 12:09:44 +0000 (15:09 +0300)
committerDavid S. Miller <davem@davemloft.net>
Tue, 9 Aug 2016 21:54:59 +0000 (14:54 -0700)
commit71fce1951632bbf0530d1dec17420c7f38943fa7
tree2673b9ff080bdb898205adc69553c51500fc83eb
parentab03717093372a0e55046676ad80fc3db16026be
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:
    [<c0108680>] __kmalloc_track_caller+0x1a4/0x230
    [<c0529eb4>] __alloc_skb+0x68/0x16c
    [<c052c884>] __netdev_alloc_skb+0x40/0x104
    [<bf1ad29c>] cpsw_ndo_open+0x374/0x670 [ti_cpsw]
    [<c053c3d4>] __dev_open+0xb0/0x114
    [<c053c690>] __dev_change_flags+0x9c/0x14c
    [<c053c760>] dev_change_flags+0x20/0x50
    [<c054bdcc>] do_setlink+0x2cc/0x78c
    [<c054c358>] rtnl_setlink+0xcc/0x100
    [<c054b34c>] rtnetlink_rcv_msg+0x184/0x224
    [<c056467c>] netlink_rcv_skb+0xa8/0xc4
    [<c054b1c0>] rtnetlink_rcv+0x2c/0x34
    [<c0564018>] netlink_unicast+0x16c/0x1f8
    [<c0564498>] netlink_sendmsg+0x334/0x348
    [<c052015c>] sock_sendmsg+0x1c/0x2c
    [<c05213e0>] 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:
    [<c0107830>] kmem_cache_alloc+0x190/0x208
    [<c052c768>] __build_skb+0x30/0x98
    [<c052c8fc>] __netdev_alloc_skb+0xb8/0x104
    [<bf1abc54>] cpsw_rx_handler+0x68/0x1e4 [ti_cpsw]
    [<bf11aa30>] __cpdma_chan_free+0xa8/0xc4 [davinci_cpdma]
    [<bf11ab98>] __cpdma_chan_process+0x14c/0x16c [davinci_cpdma]
    [<bf11abfc>] cpdma_chan_process+0x44/0x5c [davinci_cpdma]
    [<bf1adc78>] cpsw_rx_poll+0x1c/0x9c [ti_cpsw]
    [<c0539180>] net_rx_action+0x1f0/0x2ec
    [<c003881c>] __do_softirq+0x134/0x258
    [<c0038a00>] do_softirq+0x68/0x70
    [<c0038adc>] __local_bh_enable_ip+0xd4/0xe8
    [<c0640994>] _raw_spin_unlock_bh+0x30/0x34
    [<c05f4e9c>] igmp6_group_added+0x4c/0x1bc
    [<c05f6600>] ipv6_dev_mc_inc+0x398/0x434
    [<c05dba74>] 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 <catalin.marinas@arm.com>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/ethernet/ti/cpsw.c