93fc828447
[ Upstream commit c79dde629d2027ca80329c62854a7635e623d527 ] After rmmod 8250.ko tty_kref_put starts kwork (release_one_tty) to release proc interface oops when accessing driver->driver_name in proc_tty_unregister_driver Use jprobe, found driver->driver_name point to 8250.ko static static struct uart_driver serial8250_reg .driver_name= serial, Use name in proc_dir_entry instead of driver->driver_name to fix oops test on linux 4.1.12: BUG: unable to handle kernel paging request at ffffffffa01979de IP: [<ffffffff81310f40>] strchr+0x0/0x30 PGD 1a0d067 PUD 1a0e063 PMD 851c1f067 PTE 0 Oops: 0000 [#1] PREEMPT SMP Modules linked in: ... ... [last unloaded: 8250] CPU: 7 PID: 116 Comm: kworker/7:1 Tainted: G O 4.1.12 #1 Hardware name: Insyde RiverForest/Type2 - Board Product Name1, BIOS NE5KV904 12/21/2015 Workqueue: events release_one_tty task: ffff88085b684960 ti: ffff880852884000 task.ti: ffff880852884000 RIP: 0010:[<ffffffff81310f40>] [<ffffffff81310f40>] strchr+0x0/0x30 RSP: 0018:ffff880852887c90 EFLAGS: 00010282 RAX: ffffffff81a5eca0 RBX: ffffffffa01979de RCX: 0000000000000004 RDX: ffff880852887d10 RSI: 000000000000002f RDI: ffffffffa01979de RBP: ffff880852887cd8 R08: 0000000000000000 R09: ffff88085f5d94d0 R10: 0000000000000195 R11: 0000000000000000 R12: ffffffffa01979de R13: ffff880852887d00 R14: ffffffffa01979de R15: ffff88085f02e840 FS: 0000000000000000(0000) GS:ffff88085f5c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffa01979de CR3: 0000000001a0c000 CR4: 00000000001406e0 Stack: ffffffff812349b1 ffff880852887cb8 ffff880852887d10 ffff88085f5cd6c2 ffff880852800a80 ffffffffa01979de ffff880852800a84 0000000000000010 ffff88085bb28bd8 ffff880852887d38 ffffffff812354f0 ffff880852887d08 Call Trace: [<ffffffff812349b1>] ? __xlate_proc_name+0x71/0xd0 [<ffffffff812354f0>] remove_proc_entry+0x40/0x180 [<ffffffff815f6811>] ? _raw_spin_lock_irqsave+0x41/0x60 [<ffffffff813be520>] ? destruct_tty_driver+0x60/0xe0 [<ffffffff81237c68>] proc_tty_unregister_driver+0x28/0x40 [<ffffffff813be548>] destruct_tty_driver+0x88/0xe0 [<ffffffff813be5bd>] tty_driver_kref_put+0x1d/0x20 [<ffffffff813becca>] release_one_tty+0x5a/0xd0 [<ffffffff81074159>] process_one_work+0x139/0x420 [<ffffffff810745a1>] worker_thread+0x121/0x450 [<ffffffff81074480>] ? process_scheduled_works+0x40/0x40 [<ffffffff8107a16c>] kthread+0xec/0x110 [<ffffffff81080000>] ? tg_rt_schedulable+0x210/0x220 [<ffffffff8107a080>] ? kthread_freezable_should_stop+0x80/0x80 [<ffffffff815f7292>] ret_from_fork+0x42/0x70 [<ffffffff8107a080>] ? kthread_freezable_should_stop+0x80/0x80 Signed-off-by: nixiaoming <nixiaoming@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.