• Takao Indoh's avatar
    ipmi: Clear drvdata when interface is removed · 567eded9
    Takao Indoh authored
    This patch fixes a bug on hotmod removing.
    
    After ipmi interface is removed using hotmod, kernel panic occurs when
    rmmod impi_si.  For example, try this:
    
     # echo "remove,"`cat /proc/ipmi/0/params` > \
     /sys/module/ipmi_si/parameters/hotmod
     # rmmod ipmi_si
    
    Then, rmmod fails with the following messages.
    
      ------------[ cut here ]------------
      WARNING: CPU: 12 PID: 10819 at /mnt/repos/linux/lib/list_debug.c:53 __list_del_entry+0x63/0xd0()
      CPU: 12 PID: 10819 Comm: rmmod Not tainted 3.17.0-rc1 #19
      Hardware name: FUJITSU-SV PRIMERGY BX920 S2/D3030, BIOS 080015 Rev.3D81.3030 02/10/2012
      Call Trace:
        dump_stack+0x45/0x56
        warn_slowpath_common+0x7d/0xa0
        warn_slowpath_fmt+0x4c/0x50
        __list_del_entry+0x63/0xd0
        list_del+0xd/0x30
        cleanup_one_si+0x2a/0x230 [ipmi_si]
        ipmi_pnp_remove+0x15/0x20 [ipmi_si]
        pnp_device_remove+0x24/0x40
        __device_release_driver+0x7f/0xf0
        driver_detach+0xb0/0xc0
        bus_remove_driver+0x55/0xd0
        driver_unregister+0x2c/0x50
        pnp_unregister_driver+0x12/0x20
        cleanup_ipmi_si+0xbc/0xf0 [ipmi_si]
        SyS_delete_module+0x132/0x1c0
        system_call_fastpath+0x16/0x1b
      ---[ end trace 70b4377268f85c23 ]---
    
    list_del in cleanup_one_si() fails because the smi_info is already
    removed when hotmod removing.
    
    When ipmi interface is removed by hotmod, smi_info is removed by
    cleanup_one_si(), but is is still set in drvdata.  Therefore when rmmod
    ipmi_si, ipmi_pnp_remove tries to remove it again and fails.
    
    By this patch, a pointer to smi_info in drvdata is cleared when hotmod
    removing so that it will be not accessed when rmmod.
    
    changelog:
    v2:
    - Clear drvdata in cleanup_one_si
    - Change subject
    
    v1:
    https://lkml.org/lkml/2014/9/8/741Signed-off-by: default avatarTakao Indoh <indou.takao@jp.fujitsu.com>
    Signed-off-by: default avatarCorey Minyard <cminyard@mvista.com>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    567eded9
ipmi_si_intf.c 93.3 KB