linux/drivers/char/ipmi
Takao Indoh 567eded965 ipmi: Clear drvdata when interface is removed
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/2014/9/8/741

Signed-off-by: Takao Indoh <indou.takao@jp.fujitsu.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-07 13:22:32 -04:00
..
ipmi_bt_sm.c Char: ipmi_bt_sm, fix infinite loop 2014-04-17 12:23:06 -07:00
ipmi_devintf.c ipmi: info leak in compat_ipmi_ioctl() 2013-09-05 08:34:31 -07:00
ipmi_kcs_sm.c ipmi: Reset the KCS timeout when starting error recovery 2014-04-17 12:23:06 -07:00
ipmi_msghandler.c ipmi: Clean up the error handling for channel config errors 2014-10-07 13:22:32 -04:00
ipmi_poweroff.c char: Convert use of typedef ctl_table to struct ctl_table 2013-06-17 16:43:08 -07:00
ipmi_si_intf.c ipmi: Clear drvdata when interface is removed 2014-10-07 13:22:32 -04:00
ipmi_si_sm.h IPMI: Style fixes in the system interface code 2008-04-29 08:06:15 -07:00
ipmi_smic_sm.c ipmi: use USEC_PER_SEC instead of 1000000 for more meaningful 2014-01-25 15:31:58 -08:00
ipmi_watchdog.c char/ipmi: remove local ioctl defines replaced by generic ones 2012-07-23 12:48:04 +02:00
Kconfig ipmi: Turn off default probing of interfaces 2014-04-17 12:23:07 -07:00
Makefile drivers/char/ipmi/Makefile: replace the use of <module>-objs with <module>-y 2010-10-27 18:03:14 -07:00