Feras Daoud 0a0007f283 IB/ipoib: Fix deadlock between rmmod and set_mode ... When calling set_mode from sys/fs, the call flow locks the sys/fs lock first and then tries to lock rtnl_lock (when calling ipoib_set_mod). On the other hand, the rmmod call flow takes the rtnl_lock first (when calling unregister_netdev) and then tries to take the sys/fs lock. Deadlock a->b, b->a. The problem starts when ipoib_set_mod frees it's rtnl_lck and tries to get it after that. set_mod: [<ffffffff8104f2bd>] ? check_preempt_curr+0x6d/0x90 [<ffffffff814fee8e>] __mutex_lock_slowpath+0x13e/0x180 [<ffffffff81448655>] ? __rtnl_unlock+0x15/0x20 [<ffffffff814fed2b>] mutex_lock+0x2b/0x50 [<ffffffff81448675>] rtnl_lock+0x15/0x20 [<ffffffffa02ad807>] ipoib_set_mode+0x97/0x160 [ib_ipoib] [<ffffffffa02b5f5b>] set_mode+0x3b/0x80 [ib_ipoib] [<ffffffff8134b840>] dev_attr_store+0x20/0x30 [<ffffffff811f0fe5>] sysfs_write_file+0xe5/0x170 [<ffffffff8117b068>] vfs_write+0xb8/0x1a0 [<ffffffff8117ba81>] sys_write+0x51/0x90 [<ffffffff8100b0f2>] system_call_fastpath+0x16/0x1b rmmod: [<ffffffff81279ffc>] ? put_dec+0x10c/0x110 [<ffffffff8127a2ee>] ? number+0x2ee/0x320 [<ffffffff814fe6a5>] schedule_timeout+0x215/0x2e0 [<ffffffff8127cc04>] ? vsnprintf+0x484/0x5f0 [<ffffffff8127b550>] ? string+0x40/0x100 [<ffffffff814fe323>] wait_for_common+0x123/0x180 [<ffffffff81060250>] ? default_wake_function+0x0/0x20 [<ffffffff8119661e>] ? ifind_fast+0x5e/0xb0 [<ffffffff814fe43d>] wait_for_completion+0x1d/0x20 [<ffffffff811f2e68>] sysfs_addrm_finish+0x228/0x270 [<ffffffff811f2fb3>] sysfs_remove_dir+0xa3/0xf0 [<ffffffff81273f66>] kobject_del+0x16/0x40 [<ffffffff8134cd14>] device_del+0x184/0x1e0 [<ffffffff8144e59b>] netdev_unregister_kobject+0xab/0xc0 [<ffffffff8143c05e>] rollback_registered+0xae/0x130 [<ffffffff8143c102>] unregister_netdevice+0x22/0x70 [<ffffffff8143c16e>] unregister_netdev+0x1e/0x30 [<ffffffffa02a91b0>] ipoib_remove_one+0xe0/0x120 [ib_ipoib] [<ffffffffa01ed95f>] ib_unregister_device+0x4f/0x100 [ib_core] [<ffffffffa021f5e1>] mlx4_ib_remove+0x41/0x180 [mlx4_ib] [<ffffffffa01ab771>] mlx4_remove_device+0x71/0x90 [mlx4_core] Fixes: 862096a8bb ("IB/ipoib: Add more rtnl_link_ops callbacks") Cc: <stable@vger.kernel.org> # v3.6+ Cc: Or Gerlitz <ogerlitz@mellanox.com> Signed-off-by: Feras Daoud <ferasda@mellanox.com> Signed-off-by: Erez Shitrit <erezsh@mellanox.com> Signed-off-by: Leon Romanovsky <leon@kernel.org> Signed-off-by: Doug Ledford <dledford@redhat.com>		2017-01-12 14:01:03 -05:00
..
ipoib	IB/ipoib: Fix deadlock between rmmod and set_mode	2017-01-12 14:01:03 -05:00
iser	Replace <asm/uaccess.h> with <linux/uaccess.h> globally	2016-12-24 11:46:01 -08:00
isert	Merge branches 'misc', 'qedr', 'reject-helpers', 'rxe' and 'srp' into merge-test	2016-12-14 14:44:47 -05:00
srp	IB/srp: Make writing the add_target sysfs attr interruptible	2016-12-14 13:31:47 -05:00
srpt	IB/srpt: Report login failures only once	2016-12-14 12:58:30 -05:00
Makefile	IB: Allow build of hw/ and ulp/ subdirectories independently	2014-06-02 14:51:12 -07:00