From: Greg Kroah-Hartman Date: Thu, 21 May 2020 05:52:16 +0000 (+0200) Subject: drop queue-4.9/watchdog-fix-the-race-between-the-release-of-watchdog_core_data-and... X-Git-Tag: v4.4.225~76 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=75973bc58f3af538f9eaaede063585b6f7af990d;p=thirdparty%2Fkernel%2Fstable-queue.git drop queue-4.9/watchdog-fix-the-race-between-the-release-of-watchdog_core_data-and-cdev.patch --- diff --git a/queue-4.9/series b/queue-4.9/series index 62bcc841d23..531cdbf5b80 100644 --- a/queue-4.9/series +++ b/queue-4.9/series @@ -1,2 +1 @@ igb-use-igb_adapter-io_addr-instead-of-e1000_hw-hw_addr.patch -watchdog-fix-the-race-between-the-release-of-watchdog_core_data-and-cdev.patch diff --git a/queue-4.9/watchdog-fix-the-race-between-the-release-of-watchdog_core_data-and-cdev.patch b/queue-4.9/watchdog-fix-the-race-between-the-release-of-watchdog_core_data-and-cdev.patch deleted file mode 100644 index a4a9bfbab80..00000000000 --- a/queue-4.9/watchdog-fix-the-race-between-the-release-of-watchdog_core_data-and-cdev.patch +++ /dev/null @@ -1,277 +0,0 @@ -From 1cf1b24c844a037da38e6096a865bcab75aa05eb Mon Sep 17 00:00:00 2001 -From: Kevin Hao -Date: Tue, 8 Oct 2019 19:29:34 +0800 -Subject: watchdog: Fix the race between the release of watchdog_core_data and cdev - -From: Kevin Hao - -commit 72139dfa2464e43957d330266994740bb7be2535 upstream. - -The struct cdev is embedded in the struct watchdog_core_data. In the -current code, we manage the watchdog_core_data with a kref, but the -cdev is manged by a kobject. There is no any relationship between -this kref and kobject. So it is possible that the watchdog_core_data is -freed before the cdev is entirely released. We can easily get the -following call trace with CONFIG_DEBUG_KOBJECT_RELEASE and -CONFIG_DEBUG_OBJECTS_TIMERS enabled. - ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x38 - WARNING: CPU: 23 PID: 1028 at lib/debugobjects.c:481 debug_print_object+0xb0/0xf0 - Modules linked in: softdog(-) deflate ctr twofish_generic twofish_common camellia_generic serpent_generic blowfish_generic blowfish_common cast5_generic cast_common cmac xcbc af_key sch_fq_codel openvswitch nsh nf_conncount nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 - CPU: 23 PID: 1028 Comm: modprobe Not tainted 5.3.0-next-20190924-yoctodev-standard+ #180 - Hardware name: Marvell OcteonTX CN96XX board (DT) - pstate: 00400009 (nzcv daif +PAN -UAO) - pc : debug_print_object+0xb0/0xf0 - lr : debug_print_object+0xb0/0xf0 - sp : ffff80001cbcfc70 - x29: ffff80001cbcfc70 x28: ffff800010ea2128 - x27: ffff800010bad000 x26: 0000000000000000 - x25: ffff80001103c640 x24: ffff80001107b268 - x23: ffff800010bad9e8 x22: ffff800010ea2128 - x21: ffff000bc2c62af8 x20: ffff80001103c600 - x19: ffff800010e867d8 x18: 0000000000000060 - x17: 0000000000000000 x16: 0000000000000000 - x15: ffff000bd7240470 x14: 6e6968207473696c - x13: 5f72656d6974203a x12: 6570797420746365 - x11: 6a626f2029302065 x10: 7461747320657669 - x9 : 7463612820657669 x8 : 3378302f3078302b - x7 : 0000000000001d7a x6 : ffff800010fd5889 - x5 : 0000000000000000 x4 : 0000000000000000 - x3 : 0000000000000000 x2 : ffff000bff948548 - x1 : 276a1c9e1edc2300 x0 : 0000000000000000 - Call trace: - debug_print_object+0xb0/0xf0 - debug_check_no_obj_freed+0x1e8/0x210 - kfree+0x1b8/0x368 - watchdog_cdev_unregister+0x88/0xc8 - watchdog_dev_unregister+0x38/0x48 - watchdog_unregister_device+0xa8/0x100 - softdog_exit+0x18/0xfec4 [softdog] - __arm64_sys_delete_module+0x174/0x200 - el0_svc_handler+0xd0/0x1c8 - el0_svc+0x8/0xc - -This is a common issue when using cdev embedded in a struct. -Fortunately, we already have a mechanism to solve this kind of issue. -Please see commit 233ed09d7fda ("chardev: add helper function to -register char devs with a struct device") for more detail. - -In this patch, we choose to embed the struct device into the -watchdog_core_data, and use the API provided by the commit 233ed09d7fda -to make sure that the release of watchdog_core_data and cdev are -in sequence. - -Signed-off-by: Kevin Hao -Reviewed-by: Guenter Roeck -Link: https://lore.kernel.org/r/20191008112934.29669-1-haokexin@gmail.com -Signed-off-by: Guenter Roeck -Signed-off-by: Wim Van Sebroeck -[bwh: Backported to 4.9: - - There's no reboot notifier here - - Adjust context] -Signed-off-by: Ben Hutchings -Signed-off-by: Greg Kroah-Hartman ---- - drivers/watchdog/watchdog_dev.c | 67 +++++++++++++++++----------------------- - 1 file changed, 30 insertions(+), 37 deletions(-) - ---- a/drivers/watchdog/watchdog_dev.c -+++ b/drivers/watchdog/watchdog_dev.c -@@ -38,7 +38,6 @@ - #include /* For __init/__exit/... */ - #include /* For timeout functions */ - #include /* For printk/panic/... */ --#include /* For data references */ - #include /* For handling misc devices */ - #include /* For module stuff/... */ - #include /* For mutexes */ -@@ -53,14 +52,14 @@ - - /* - * struct watchdog_core_data - watchdog core internal data -- * @kref: Reference count. -+ * @dev: The watchdog's internal device - * @cdev: The watchdog's Character device. - * @wdd: Pointer to watchdog device. - * @lock: Lock for watchdog core. - * @status: Watchdog core internal status bits. - */ - struct watchdog_core_data { -- struct kref kref; -+ struct device dev; - struct cdev cdev; - struct watchdog_device *wdd; - struct mutex lock; -@@ -794,7 +793,7 @@ static int watchdog_open(struct inode *i - file->private_data = wd_data; - - if (!hw_running) -- kref_get(&wd_data->kref); -+ get_device(&wd_data->dev); - - /* dev/watchdog is a virtual (and thus non-seekable) filesystem */ - return nonseekable_open(inode, file); -@@ -806,11 +805,11 @@ out_clear: - return err; - } - --static void watchdog_core_data_release(struct kref *kref) -+static void watchdog_core_data_release(struct device *dev) - { - struct watchdog_core_data *wd_data; - -- wd_data = container_of(kref, struct watchdog_core_data, kref); -+ wd_data = container_of(dev, struct watchdog_core_data, dev); - - kfree(wd_data); - } -@@ -870,7 +869,7 @@ done: - */ - if (!running) { - module_put(wd_data->cdev.owner); -- kref_put(&wd_data->kref, watchdog_core_data_release); -+ put_device(&wd_data->dev); - } - return 0; - } -@@ -889,17 +888,22 @@ static struct miscdevice watchdog_miscde - .fops = &watchdog_fops, - }; - -+static struct class watchdog_class = { -+ .name = "watchdog", -+ .owner = THIS_MODULE, -+ .dev_groups = wdt_groups, -+}; -+ - /* - * watchdog_cdev_register: register watchdog character device - * @wdd: watchdog device -- * @devno: character device number - * - * Register a watchdog character device including handling the legacy - * /dev/watchdog node. /dev/watchdog is actually a miscdevice and - * thus we set it up like that. - */ - --static int watchdog_cdev_register(struct watchdog_device *wdd, dev_t devno) -+static int watchdog_cdev_register(struct watchdog_device *wdd) - { - struct watchdog_core_data *wd_data; - int err; -@@ -907,7 +911,6 @@ static int watchdog_cdev_register(struct - wd_data = kzalloc(sizeof(struct watchdog_core_data), GFP_KERNEL); - if (!wd_data) - return -ENOMEM; -- kref_init(&wd_data->kref); - mutex_init(&wd_data->lock); - - wd_data->wdd = wdd; -@@ -934,23 +937,33 @@ static int watchdog_cdev_register(struct - } - } - -+ device_initialize(&wd_data->dev); -+ wd_data->dev.devt = MKDEV(MAJOR(watchdog_devt), wdd->id); -+ wd_data->dev.class = &watchdog_class; -+ wd_data->dev.parent = wdd->parent; -+ wd_data->dev.groups = wdd->groups; -+ wd_data->dev.release = watchdog_core_data_release; -+ dev_set_drvdata(&wd_data->dev, wdd); -+ dev_set_name(&wd_data->dev, "watchdog%d", wdd->id); -+ - /* Fill in the data structures */ - cdev_init(&wd_data->cdev, &watchdog_fops); -- wd_data->cdev.owner = wdd->ops->owner; - - /* Add the device */ -- err = cdev_add(&wd_data->cdev, devno, 1); -+ err = cdev_device_add(&wd_data->cdev, &wd_data->dev); - if (err) { - pr_err("watchdog%d unable to add device %d:%d\n", - wdd->id, MAJOR(watchdog_devt), wdd->id); - if (wdd->id == 0) { - misc_deregister(&watchdog_miscdev); - old_wd_data = NULL; -- kref_put(&wd_data->kref, watchdog_core_data_release); -+ put_device(&wd_data->dev); - } - return err; - } - -+ wd_data->cdev.owner = wdd->ops->owner; -+ - /* Record time of most recent heartbeat as 'just before now'. */ - wd_data->last_hw_keepalive = jiffies - 1; - -@@ -960,7 +973,7 @@ static int watchdog_cdev_register(struct - */ - if (watchdog_hw_running(wdd)) { - __module_get(wdd->ops->owner); -- kref_get(&wd_data->kref); -+ get_device(&wd_data->dev); - queue_delayed_work(watchdog_wq, &wd_data->work, 0); - } - -@@ -979,7 +992,7 @@ static void watchdog_cdev_unregister(str - { - struct watchdog_core_data *wd_data = wdd->wd_data; - -- cdev_del(&wd_data->cdev); -+ cdev_device_del(&wd_data->cdev, &wd_data->dev); - if (wdd->id == 0) { - misc_deregister(&watchdog_miscdev); - old_wd_data = NULL; -@@ -992,15 +1005,9 @@ static void watchdog_cdev_unregister(str - - cancel_delayed_work_sync(&wd_data->work); - -- kref_put(&wd_data->kref, watchdog_core_data_release); -+ put_device(&wd_data->dev); - } - --static struct class watchdog_class = { -- .name = "watchdog", -- .owner = THIS_MODULE, -- .dev_groups = wdt_groups, --}; -- - /* - * watchdog_dev_register: register a watchdog device - * @wdd: watchdog device -@@ -1012,27 +1019,14 @@ static struct class watchdog_class = { - - int watchdog_dev_register(struct watchdog_device *wdd) - { -- struct device *dev; -- dev_t devno; - int ret; - -- devno = MKDEV(MAJOR(watchdog_devt), wdd->id); -- -- ret = watchdog_cdev_register(wdd, devno); -+ ret = watchdog_cdev_register(wdd); - if (ret) - return ret; - -- dev = device_create_with_groups(&watchdog_class, wdd->parent, -- devno, wdd, wdd->groups, -- "watchdog%d", wdd->id); -- if (IS_ERR(dev)) { -- watchdog_cdev_unregister(wdd); -- return PTR_ERR(dev); -- } -- - ret = watchdog_register_pretimeout(wdd); - if (ret) { -- device_destroy(&watchdog_class, devno); - watchdog_cdev_unregister(wdd); - } - -@@ -1050,7 +1044,6 @@ int watchdog_dev_register(struct watchdo - void watchdog_dev_unregister(struct watchdog_device *wdd) - { - watchdog_unregister_pretimeout(wdd); -- device_destroy(&watchdog_class, wdd->wd_data->cdev.dev); - watchdog_cdev_unregister(wdd); - } -