Re: [RFC PATCH v2 10/16] ACPIHP: system device hotplug driver skeleton

From: Tang Chen
Date: Thu Aug 09 2012 - 03:10:34 EST


Hi Liu~

I compiled this driver as a module, acpihp_drv. And when I loaded this module, it
gave the following error message:

# modprobe acpihp_drv
(the command hangs up, no return after 10 min)

#dmesg
......
[ 126.643350] BUG: unable to handle kernel NULL pointer dereference at 0000000000000078
[ 126.644007] IP: [<ffffffff814c0cd3>] mutex_lock+0x19/0x37
[ 126.644007] PGD 105277a067 PUD 104f823067 PMD 0
[ 126.644007] Oops: 0002 [#1] SMP
[ 126.644007] Modules linked in: acpihp_drv(+) ebtable_nat ebtables ipt_MASQUERADE iptable_nat nf_nat iptable_mangle bridge stp llc sunrpc cpufreq_ondemand acpi_cpufreq freq_table mperf ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter ip6_tables ipv6 vhost_net macvtap macvlan tun uinput iTCO_wdt iTCO_vendor_support coretemp kvm_intel kvm crc32c_intel microcode lpc_ich mfd_core pcspkr i2c_i801 i2c_core ioatdma e1000e acpi_memhotplug i7core_edac edac_core igb dca mptsas mptscsih mptbase scsi_transport_sas
[ 126.644007] CPU 10
[ 126.644007] Pid: 2821, comm: modprobe Tainted: G A 3.6.0-rc1+ #6 FUJITSU-SV PRIMEQUEST 1800E/SB
[ 126.644007] RIP: 0010:[<ffffffff814c0cd3>] [<ffffffff814c0cd3>] mutex_lock+0x19/0x37
[ 126.644007] RSP: 0018:ffff8810589a9de8 EFLAGS: 00010246
[ 126.644007] RAX: 0000000000000000 RBX: 0000000000000078 RCX: 0000000000000000
[ 126.644007] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000078
[ 126.644007] RBP: ffff8810589a9e08 R08: 0000000000000000 R09: ffff8810589a9d88
[ 126.644007] R10: 00000000000013e5 R11: 00000000000013e5 R12: ffffffffa01460d0
[ 126.644007] R13: 0000000000000000 R14: ffffffffa014732b R15: 00000000000000bf
[ 126.644007] FS: 00007fecb1802700(0000) GS:ffff88105e640000(0000) knlGS:0000000000000000
[ 126.644007] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 126.644007] CR2: 0000000000000078 CR3: 0000001052772000 CR4: 00000000000007e0
[ 126.644007] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 126.644007] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[ 126.644007] Process modprobe (pid: 2821, threadinfo ffff8810589a8000, task ffff8810592f8000)
[ 126.644007] Stack:
[ 126.644007] ffff8810589a9e08 ffffffff810be37f ffffffffa0146220 ffffffff81a7b390
[ 126.644007] ffff8810589a9e58 ffffffff81317eb3 ffff8810589a9e48 0000000000000000
[ 126.644007] ffffffff81a342c0 ffffffff81a342e0 0000000000000000 ffffffffa0146220
[ 126.644007] Call Trace:
[ 126.644007] [<ffffffff810be37f>] ? tracepoint_module_notify+0xd9/0x14a
[ 126.644007] [<ffffffff81317eb3>] class_interface_register+0x4a/0xbc
[ 126.644007] [<ffffffffa00b8000>] ? 0xffffffffa00b7fff
[ 126.644007] [<ffffffffa00b8010>] acpihp_drv_init+0x10/0x12 [acpihp_drv]
[ 126.644007] [<ffffffff8100207f>] do_one_initcall+0x7f/0x139
[ 126.644007] [<ffffffff81093414>] sys_init_module+0x12d3/0x14e3
[ 126.644007] [<ffffffff81264b0d>] ? ddebug_dyndbg_boot_param_cb+0x45/0x45
[ 126.644007] [<ffffffff814c9469>] system_call_fastpath+0x16/0x1b
[ 126.644007] Code: 48 8b 04 25 80 c6 00 00 48 89 43 18 31 c0 5b 5b c9 c3 55 48 89 e5 53 48 83 ec 18 66 66 66 66 90 48 89 fb e8 5a 0c 00 00 48 89 df <f0> ff 0f 79 05 e8 06 ff ff ff 65 48 8b 04 25 80 c6 00 00 48 89
[ 126.644007] RIP [<ffffffff814c0cd3>] mutex_lock+0x19/0x37
[ 126.644007] RSP <ffff8810589a9de8>
[ 126.644007] CR2: 0000000000000078
[ 129.981335] ---[ end trace da17e9c9de8dd560 ]---
[ 139.085895] nr_pdflush_threads exported in /proc is scheduled for removal
[ 139.167394] sysctl: The scan_unevictable_pages sysctl/node-interface has been disabled for lack of a legitimate use case. If you have one, please send an email to linux-mm@xxxxxxxxxx

Looks like it dereferenced a NULL pointer here.
May be it was my mistake that I didn't configure the environment correctly.
Would you please give me some advice ?

Thanks. :)


On 08/04/2012 08:13 PM, Jiang Liu wrote:
> From: Jiang Liu <jiang.liu@xxxxxxxxxx>
>
> This patch implements a skeleton for ACPI based system device hotplug driver.
> This device class driver will be bound to and manage ACPI hotplug slots.
>
> This is the default hotplug driver for ACPI based system device hotplug.
>
> Signed-off-by: Jiang Liu <liuj97@xxxxxxxxx>
> Signed-off-by: Hanjun Guo <guohanjun@xxxxxxxxxx>
> ---
> drivers/acpi/Kconfig | 12 ++
> drivers/acpi/hotplug/Makefile | 3 +
> drivers/acpi/hotplug/acpihp_drv.h | 62 +++++++
> drivers/acpi/hotplug/drv_main.c | 331 +++++++++++++++++++++++++++++++++++++
> 4 files changed, 408 insertions(+)
> create mode 100644 drivers/acpi/hotplug/acpihp_drv.h
> create mode 100644 drivers/acpi/hotplug/drv_main.c
>
> diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
> index c9f7918..89047a3 100644
> --- a/drivers/acpi/Kconfig
> +++ b/drivers/acpi/Kconfig
> @@ -354,6 +354,18 @@ config ACPI_HOTPLUG_ENUM_EJ0
>
> It's the default method to detect ACPI hotplug slots.
>
> +config ACPI_HOTPLUG_DRIVER
> + tristate "ACPI Based System Device Hotplug Driver"
> + depends on ACPI_HOTPLUG
> + default y
> + help
> + This driver enables ACPI based system device hotplug, including
> + physical processor, memory device, IO host bridge and computer
> + node etc.
> +
> + To compile this driver as a module, choose M here:
> + the module will be called acpihp_drv.
> +
> config ACPI_CONTAINER
> tristate "Container and Module Devices (EXPERIMENTAL)"
> depends on EXPERIMENTAL
> diff --git a/drivers/acpi/hotplug/Makefile b/drivers/acpi/hotplug/Makefile
> index 25fac24..d69832f 100644
> --- a/drivers/acpi/hotplug/Makefile
> +++ b/drivers/acpi/hotplug/Makefile
> @@ -8,3 +8,6 @@ acpihp-y = core.o device.o
> obj-$(CONFIG_ACPI_HOTPLUG_ENUM) += acpihp_enum.o
> acpihp_enum-y = slot_enum.o
> acpihp_enum-y += slot_enum_ej0.o
> +
> +obj-$(CONFIG_ACPI_HOTPLUG_DRIVER) += acpihp_drv.o
> +acpihp_drv-y = drv_main.o
> diff --git a/drivers/acpi/hotplug/acpihp_drv.h b/drivers/acpi/hotplug/acpihp_drv.h
> new file mode 100644
> index 0000000..18330f7
> --- /dev/null
> +++ b/drivers/acpi/hotplug/acpihp_drv.h
> @@ -0,0 +1,62 @@
> +/*
> + * Copyright (C) 2011 Huawei Tech. Co., Ltd.
> + * Copyright (C) 2011 Jiang Liu <jiang.liu@xxxxxxxxxx>
> + * Copyright (C) 2011 Hanjun Guo <guohanjun@xxxxxxxxxx>
> + *
> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
> + *
> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + */
> +
> +#ifndef __ACPIHP_DRV_H__
> +#define __ACPIHP_DRV_H__
> +
> +/* Commands to change state of a hotplug slot */
> +enum acpihp_drv_cmd {
> + ACPIHP_DRV_CMD_NOOP = 0,
> + ACPIHP_DRV_CMD_POWERON = 0x1,
> + ACPIHP_DRV_CMD_CONNECT = 0x2,
> + ACPIHP_DRV_CMD_CONFIGURE = 0x4,
> + ACPIHP_DRV_CMD_UNCONFIGURE = 0x8,
> + ACPIHP_DRV_CMD_DISCONNECT = 0x10,
> + ACPIHP_DRV_CMD_POWEROFF = 0x20,
> + ACPIHP_DRV_CMD_CANCEL = 0x40,
> + ACPIHP_DRV_CMD_MAX
> +};
> +
> +/* Hotplug operations may be triggered by firmware or OS */
> +enum acpihp_dev_event {
> + ACPIHP_DRV_EVENT_FROM_FW,
> + ACPIHP_DRV_EVENT_FROM_OS
> +};
> +
> +struct acpihp_slot_drv {
> + enum acpihp_dev_event event_flag;
> + struct mutex op_mutex; /* Prevent concurrent hotplugs. */
> + struct list_head depend_list; /* Dependency relationship */
> + atomic_t cancel_status;
> + atomic_t cancel_flag;
> + struct acpihp_cancel_context cancel_ctx;
> +};
> +
> +void acpihp_drv_get_data(struct acpihp_slot *slot,
> + struct acpihp_slot_drv **data);
> +int acpihp_drv_enumerate_devices(struct acpihp_slot *slot);
> +void acpihp_drv_update_slot_state(struct acpihp_slot *slot);
> +int acpihp_drv_update_slot_status(struct acpihp_slot *slot);
> +
> +#endif /* __ACPIHP_DRV_H__ */
> diff --git a/drivers/acpi/hotplug/drv_main.c b/drivers/acpi/hotplug/drv_main.c
> new file mode 100644
> index 0000000..538772d
> --- /dev/null
> +++ b/drivers/acpi/hotplug/drv_main.c
> @@ -0,0 +1,331 @@
> +/*
> + * Copyright (C) 2011 Huawei Tech. Co., Ltd.
> + * Copyright (C) 2011 Jiang Liu <jiang.liu@xxxxxxxxxx>
> + * Copyright (C) 2011 Hanjun Guo <guohanjun@xxxxxxxxxx>
> + *
> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
> + *
> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/errno.h>
> +#include <linux/types.h>
> +#include <linux/list.h>
> +#include <linux/mutex.h>
> +#include <linux/kthread.h>
> +#include <linux/delay.h>
> +#include <linux/acpi.h>
> +#include <acpi/acpi_hotplug.h>
> +#include "acpihp_drv.h"
> +
> +static struct class_interface acpihp_drv_interface;
> +
> +void acpihp_drv_get_data(struct acpihp_slot *slot,
> + struct acpihp_slot_drv **data)
> +{
> + *data = NULL;
> + acpihp_slot_get_drv_data(slot, &acpihp_drv_interface, (void **)data);
> +}
> +
> +/* Update slot state according to state of devices connecting to it. */
> +void acpihp_drv_update_slot_state(struct acpihp_slot *slot)
> +{
> + enum acpihp_dev_type type;
> + enum acpihp_slot_state state;
> + struct klist_iter iter;
> + struct klist_node *ip;
> + struct acpihp_dev_node *dp;
> + bool connected = false;
> + bool configured = false;
> +
> + if (!acpihp_slot_present(slot)) {
> + state = ACPIHP_SLOT_STATE_ABSENT;
> + goto out;
> + } else if (!acpihp_slot_powered(slot)) {
> + state = ACPIHP_SLOT_STATE_PRESENT;
> + goto out;
> + }
> +
> + for (type = ACPIHP_DEV_TYPE_UNKNOWN;
> + type < ACPIHP_DEV_TYPE_MAX && !configured;
> + type++) {
> + klist_iter_init(&slot->dev_lists[type], &iter);
> + while ((ip = klist_next(&iter)) != NULL) {
> + connected = true;
> + dp = container_of(ip, struct acpihp_dev_node, node);
> + if (dp->state == DEVICE_STATE_CONFIGURED) {
> + configured = true;
> + break;
> + }
> + }
> + klist_iter_exit(&iter);
> + }
> +
> + if (configured)
> + state = ACPIHP_SLOT_STATE_CONFIGURED;
> + else if (connected)
> + state = ACPIHP_SLOT_STATE_CONNECTED;
> + else
> + state = ACPIHP_SLOT_STATE_POWERED;
> +
> +out:
> + acpihp_slot_change_state(slot, state);
> +}
> +
> +/* Update slot state according to status of devices connecting to it. */
> +int acpihp_drv_update_slot_status(struct acpihp_slot *slot)
> +{
> + int ret = 0;
> + enum acpihp_dev_type type;
> + struct klist_iter iter;
> + struct klist_node *ip;
> + struct acpihp_dev_node *np;
> + struct acpi_device *dev;
> + struct acpihp_dev_info *info;
> +
> + if (!slot)
> + return -EINVAL;
> +
> + info = kzalloc(sizeof(*info), GFP_KERNEL);
> + if (!info)
> + return -ENOMEM;
> +
> + for (type = ACPIHP_DEV_TYPE_MEM; type <= ACPIHP_DEV_TYPE_HOST_BRIDGE;
> + type++) {
> + klist_iter_init(&slot->dev_lists[type], &iter);
> + while ((ip = klist_next(&iter)) != NULL) {
> + np = container_of(ip, struct acpihp_dev_node, node);
> + dev = container_of(np->dev, struct acpi_device, dev);
> + ret = acpihp_dev_get_info(dev, info);
> + if (ret) {
> + ACPIHP_DEBUG("fails to get info about %s.\n",
> + dev_name(&dev->dev));
> + goto out;
> + }
> +
> + if (info->status & ACPIHP_DEV_STATUS_FAULT)
> + acpihp_slot_set_flag(slot,
> + ACPIHP_SLOT_FLAG_FAULT);
> + if (info->status & ACPIHP_DEV_STATUS_IRREMOVABLE)
> + acpihp_slot_set_flag(slot,
> + ACPIHP_SLOT_FLAG_IRREMOVABLE);
> + }
> + }
> +
> +out:
> + kfree(info);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL(acpihp_drv_update_slot_status);
> +
> +/* Add ACPI device to hotplug slot's device list */
> +static acpi_status acpihp_drv_enum_device(struct acpi_device *dev, void *argp)
> +{
> + int ret = -ENOMEM;
> + acpi_status rv = AE_OK;
> + enum acpihp_dev_type type;
> + enum acpihp_dev_state state;
> + struct acpihp_dev_info *info;
> + struct acpihp_slot *slot = (struct acpihp_slot *)argp;
> +
> + if (acpihp_dev_get_type(dev->handle, &type)) {
> + ACPIHP_DEBUG("fails to get device type of %s.\n",
> + dev_name(&dev->dev));
> + return AE_ERROR;
> + } else if (type == ACPIHP_DEV_TYPE_MAX) {
> + /*
> + * Some ACPI objects for IO devices, such as PCI/IDE etc, only
> + * implement _ADR instead of _HID/_CID, skip them.
> + */
> + return AE_CTRL_DEPTH;
> + }
> +
> + info = kzalloc(sizeof(*info), GFP_KERNEL);
> + if (info)
> + ret = acpihp_dev_get_info(dev, info);
> +
> + if (!ret) {
> + if (info->status & ACPIHP_DEV_STATUS_STARTED)
> + state = DEVICE_STATE_CONFIGURED;
> + else
> + state = DEVICE_STATE_CONNECTED;
> +
> + if (info->status & ACPIHP_DEV_STATUS_IRREMOVABLE)
> + acpihp_slot_set_flag(slot,
> + ACPIHP_SLOT_FLAG_IRREMOVABLE);
> + if (info->status & ACPIHP_DEV_STATUS_FAULT)
> + acpihp_slot_set_flag(slot, ACPIHP_SLOT_FLAG_FAULT);
> +
> + if (acpihp_slot_add_device(slot, type, state, &dev->dev)) {
> + ACPIHP_DEBUG("fails to add %s to slot %s.\n",
> + dev_name(&dev->dev), slot->name);
> + rv = AE_ERROR;
> + }
> + } else {
> + ACPIHP_DEBUG("fails to query device info of %s.\n",
> + dev_name(&dev->dev));
> + }
> +
> + kfree(info);
> +
> + return rv;
> +}
> +
> +/*
> + * Enumerator all devices connecting to a slot and add them onto slot's
> + * device lists.
> + */
> +int acpihp_drv_enumerate_devices(struct acpihp_slot *slot)
> +{
> + return acpihp_walk_devices(slot->handle, acpihp_drv_enum_device, slot);
> +}
> +
> +static void acpihp_drv_remove_devices(struct acpihp_slot *slot)
> +{
> + enum acpihp_dev_type type;
> +
> + for (type = ACPIHP_DEV_TYPE_UNKNOWN; type < ACPIHP_DEV_TYPE_MAX; type++)
> + acpihp_remove_device_list(&slot->dev_lists[type]);
> +}
> +
> +/* Callback function for ACPI system event notification. */
> +static void acpihp_drv_event_handler(acpi_handle handle, u32 event,
> + void *context)
> +{
> + /* TODO: handle ACPI hotplug events */
> +}
> +
> +static acpi_status acpihp_drv_install_handler(struct acpihp_slot *slot)
> +{
> + acpi_status status;
> +
> + status = acpi_install_notify_handler(slot->handle, ACPI_SYSTEM_NOTIFY,
> + acpihp_drv_event_handler, slot);
> + ACPIHP_DEBUG("%s to install event handler for %s.\n",
> + ACPI_SUCCESS(status) ? "succeeds" : "fails", slot->name);
> +
> + return status;
> +}
> +
> +static void acpihp_drv_uninstall_handler(struct acpihp_slot *slot)
> +{
> + acpi_status status;
> +
> + status = acpi_remove_notify_handler(slot->handle, ACPI_SYSTEM_NOTIFY,
> + acpihp_drv_event_handler);
> + ACPIHP_DEBUG("%s to uninstall event handler for %s.\n",
> + ACPI_SUCCESS(status) ? "succeeds" : "fails", slot->name);
> +}
> +
> +static int acpihp_drv_slot_add(struct device *dev, struct class_interface *intf)
> +{
> + struct acpihp_slot_drv *drv_data;
> + struct acpihp_slot *slot = container_of(dev, struct acpihp_slot, dev);
> +
> + /*
> + * Try to hold a reference to the slot_ops structure to prevent
> + * the platform specific enumerator driver from unloading.
> + */
> + if (!slot->slot_ops || !try_module_get(slot->slot_ops->owner)) {
> + ACPIHP_DEBUG("fails to get reference to slot_ops for %s.\n",
> + slot->name);
> + return -EINVAL;
> + }
> +
> + /* install ACPI event notification handler for slot */
> + if (ACPI_FAILURE(acpihp_drv_install_handler(slot))) {
> + ACPIHP_DEBUG("fails to install event handler for %s.\n",
> + slot->name);
> + module_put(slot->slot_ops->owner);
> + return -EBUSY;
> + }
> +
> + /* Enumerate all devices if slot is already powered. */
> + if (!acpihp_slot_powered(slot))
> + ACPIHP_DEBUG("slot %s is powered off.\n", slot->name);
> + else if (acpihp_drv_enumerate_devices(slot))
> + acpihp_slot_set_flag(slot, ACPIHP_SLOT_FLAG_IRREMOVABLE);
> +
> + acpihp_drv_update_slot_state(slot);
> +
> + drv_data = kzalloc(sizeof(*drv_data), GFP_KERNEL);
> + if (drv_data) {
> + drv_data->event_flag = ACPIHP_DRV_EVENT_FROM_FW;
> + mutex_init(&drv_data->op_mutex);
> + INIT_LIST_HEAD(&drv_data->depend_list);
> + }
> + if (drv_data == NULL ||
> + acpihp_slot_attach_drv_data(slot, intf, (void *)drv_data)) {
> + ACPIHP_DEBUG("fails to attach driver data for %s.\n",
> + slot->name);
> + acpihp_drv_remove_devices(slot);
> + module_put(slot->slot_ops->owner);
> + kfree(drv_data);
> + return -ENOMEM;
> + }
> +
> + ACPIHP_INFO("found hotplug slot %s.\n", slot->full_path);
> +
> + return 0;
> +}
> +
> +static void acpihp_drv_intf_remove(struct device *dev,
> + struct class_interface *intf)
> +{
> + struct acpihp_slot_drv *drv_data = NULL;
> + struct acpihp_slot *slot =
> + container_of(dev, struct acpihp_slot, dev);
> +
> + ACPIHP_INFO("remove hotplug slot %s.\n", slot->full_path);
> +
> + acpihp_drv_uninstall_handler(slot);
> + acpihp_drv_remove_devices(slot);
> + acpihp_slot_detach_drv_data(slot, intf, (void **)&drv_data);
> + if (drv_data != NULL)
> + kfree(drv_data);
> +
> + module_put(slot->slot_ops->owner);
> +}
> +
> +/*
> + * register a class driver onto the acpihp_slot_class to manage all system
> + * device hotplug slots.
> + */
> +static struct class_interface acpihp_drv_interface = {
> + .class = &acpihp_slot_class,
> + .add_dev = acpihp_drv_slot_add,
> + .remove_dev = acpihp_drv_intf_remove,
> +};
> +
> +static int __init acpihp_drv_init(void)
> +{
> + return class_interface_register(&acpihp_drv_interface);
> +}
> +
> +static void __exit acpihp_drv_exit(void)
> +{
> + class_interface_unregister(&acpihp_drv_interface);
> +}
> +
> +module_init(acpihp_drv_init);
> +module_exit(acpihp_drv_exit);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_AUTHOR("Jiang Liu <jiang.liu@xxxxxxxxxx>");
> +MODULE_AUTHOR("Hanjun Guo <guohanjun@xxxxxxxxxx>");

--
Best Regards,
Tang chen
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