From: Takao Indoh <indou.ta...@jp.fujitsu.com> 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() (snip) 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 0000000000000009 ffff88022d547d40 ffffffff81575778 ffff88022d547d88 ffff88022d547d78 ffffffff8104ec5d ffff88023908cdb0 ffffffffa06fa4e0 ffff8800bac20860 0000000000000000 0000000002046090 ffff88022d547dd8 Call Trace: [<ffffffff81575778>] dump_stack+0x45/0x56 [<ffffffff8104ec5d>] warn_slowpath_common+0x7d/0xa0 [<ffffffff8104eccc>] warn_slowpath_fmt+0x4c/0x50 [<ffffffff811f60bf>] ? __kernfs_remove+0xdf/0x220 [<ffffffff81291213>] __list_del_entry+0x63/0xd0 [<ffffffff8129128d>] list_del+0xd/0x30 [<ffffffffa06f285a>] cleanup_one_si+0x2a/0x230 [ipmi_si] [<ffffffffa06f2f05>] ipmi_pnp_remove+0x15/0x20 [ipmi_si] [<ffffffff8131c7d4>] pnp_device_remove+0x24/0x40 [<ffffffff8137175f>] __device_release_driver+0x7f/0xf0 [<ffffffff81372100>] driver_detach+0xb0/0xc0 [<ffffffff81371415>] bus_remove_driver+0x55/0xd0 [<ffffffff8137283c>] driver_unregister+0x2c/0x50 [<ffffffff8131ca02>] pnp_unregister_driver+0x12/0x20 [<ffffffffa06f347c>] cleanup_ipmi_si+0xbc/0xf0 [ipmi_si] [<ffffffff810c33f2>] SyS_delete_module+0x132/0x1c0 [<ffffffff81002ab9>] ? do_notify_resume+0x59/0x80 [<ffffffff8157c45a>] ? int_signal+0x12/0x17 [<ffffffff8157c1d2>] 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.ta...@jp.fujitsu.com> Signed-off-by: Corey Minyard <cminy...@mvista.com> --- drivers/char/ipmi/ipmi_si_intf.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c index 1c43f9a..5c4e1f6 100644 --- a/drivers/char/ipmi/ipmi_si_intf.c +++ b/drivers/char/ipmi/ipmi_si_intf.c @@ -3658,6 +3658,9 @@ static void cleanup_one_si(struct smi_info *to_clean) if (!to_clean) return; + if (to_clean->dev) + dev_set_drvdata(to_clean->dev, NULL); + list_del(&to_clean->link); /* Tell the driver that we are shutting down. */ -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
