diff options
| author | nixiaoming <nixiaoming@huawei.com> | 2017-09-15 17:45:56 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-10-20 14:06:45 +0200 |
| commit | c79dde629d2027ca80329c62854a7635e623d527 (patch) | |
| tree | 90304a4ab9592c672da3adc697ef39d2e8b06986 | |
| parent | 0ab84da2e076948c49d36197ee7d254125c53eab (diff) | |
| download | linux-c79dde629d2027ca80329c62854a7635e623d527.tar.gz linux-c79dde629d2027ca80329c62854a7635e623d527.tar.bz2 linux-c79dde629d2027ca80329c62854a7635e623d527.zip | |
tty fix oops when rmmod 8250
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>
| -rw-r--r-- | fs/proc/proc_tty.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/proc/proc_tty.c b/fs/proc/proc_tty.c index 901bd06f437d..20e2c18e2b47 100644 --- a/fs/proc/proc_tty.c +++ b/fs/proc/proc_tty.c @@ -14,6 +14,7 @@ #include <linux/tty.h> #include <linux/seq_file.h> #include <linux/bitops.h> +#include "internal.h" /* * The /proc/tty directory inodes... @@ -164,7 +165,7 @@ void proc_tty_unregister_driver(struct tty_driver *driver) if (!ent) return; - remove_proc_entry(driver->driver_name, proc_tty_driver); + remove_proc_entry(ent->name, proc_tty_driver); driver->proc_entry = NULL; } |