修改内核路径

hc

2024-05-14 bedbef8ad3e75a304af6361af235302bcc61d06b

 kernel/drivers/watchdog/watchdog_core.c
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@@ -1,3 +1,4 @@
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+// SPDX-License-Identifier: GPL-2.0+
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 /*
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  *	watchdog_core.c
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  *
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@@ -15,11 +16,6 @@
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  *	  Rusty Lynch <rusty@linux.co.intel.com>
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  *	  Satyam Sharma <satyam@infradead.org>
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  *	  Randy Dunlap <randy.dunlap@oracle.com>
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- *
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- *	This program is free software; you can redistribute it and/or
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- *	modify it under the terms of the GNU General Public License
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- *	as published by the Free Software Foundation; either version
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- *	2 of the License, or (at your option) any later version.
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  *
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  *	Neither Alan Cox, CymruNet Ltd., Wim Van Sebroeck nor Iguana vzw.
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  *	admit liability nor provide warranty for any of this software.
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@@ -43,6 +39,10 @@
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39
 
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 static DEFINE_IDA(watchdog_ida);
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+static int stop_on_reboot = -1;
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+module_param(stop_on_reboot, int, 0444);
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+MODULE_PARM_DESC(stop_on_reboot, "Stop watchdogs on reboot (0=keep watching, 1=stop)");
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+
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 /*
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  * Deferred Registration infrastructure.
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  *
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@@ -60,11 +60,10 @@
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 static LIST_HEAD(wtd_deferred_reg_list);
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 static bool wtd_deferred_reg_done;
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-static int watchdog_deferred_registration_add(struct watchdog_device *wdd)
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+static void watchdog_deferred_registration_add(struct watchdog_device *wdd)
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 {
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 	list_add_tail(&wdd->deferred,
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 		      &wtd_deferred_reg_list);
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-	return 0;
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 }
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68
 
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 static void watchdog_deferred_registration_del(struct watchdog_device *wdd)
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@@ -105,34 +104,48 @@
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  * timeout module parameter (if it is valid value) or the timeout-sec property
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  * (only if it is a valid value and the timeout_parm is out of bounds).
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  * If none of them are valid then we keep the old value (which should normally
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- * be the default timeout value).
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+ * be the default timeout value). Note that for the module parameter, '0' means
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+ * 'use default' while it is an invalid value for the timeout-sec property.
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+ * It should simply be dropped if you want to use the default value then.
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  *
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- * A zero is returned on success and -EINVAL for failure.
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+ * A zero is returned on success or -EINVAL if all provided values are out of
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+ * bounds.
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  */
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 int watchdog_init_timeout(struct watchdog_device *wdd,
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 				unsigned int timeout_parm, struct device *dev)
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 {
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+	const char *dev_str = wdd->parent ? dev_name(wdd->parent) :
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+			      (const char *)wdd->info->identity;
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 	unsigned int t = 0;
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 	int ret = 0;
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 	watchdog_check_min_max_timeout(wdd);
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-	/* try to get the timeout module parameter first */
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-	if (!watchdog_timeout_invalid(wdd, timeout_parm) && timeout_parm) {
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-		wdd->timeout = timeout_parm;
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-		return ret;
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-	}
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-	if (timeout_parm)
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+	/* check the driver supplied value (likely a module parameter) first */
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+	if (timeout_parm) {
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+		if (!watchdog_timeout_invalid(wdd, timeout_parm)) {
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+			wdd->timeout = timeout_parm;
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+			return 0;
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+		}
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+		pr_err("%s: driver supplied timeout (%u) out of range\n",
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+			dev_str, timeout_parm);
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 		ret = -EINVAL;
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+	}
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 	/* try to get the timeout_sec property */
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-	if (dev == NULL || dev->of_node == NULL)
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-		return ret;
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-	of_property_read_u32(dev->of_node, "timeout-sec", &t);
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-	if (!watchdog_timeout_invalid(wdd, t) && t)
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-		wdd->timeout = t;
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-	else
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+	if (dev && dev->of_node &&
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+	    of_property_read_u32(dev->of_node, "timeout-sec", &t) == 0) {
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+		if (t && !watchdog_timeout_invalid(wdd, t)) {
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+			wdd->timeout = t;
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+			return 0;
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+		}
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+		pr_err("%s: DT supplied timeout (%u) out of range\n", dev_str, t);
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 		ret = -EINVAL;
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+	}
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+
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+	if (ret < 0 && wdd->timeout)
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+		pr_warn("%s: falling back to default timeout (%u)\n", dev_str,
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+			wdd->timeout);
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 	return ret;
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 }
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@@ -245,6 +258,14 @@
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 		}
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 	}
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+	/* Module parameter to force watchdog policy on reboot. */
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+	if (stop_on_reboot != -1) {
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+		if (stop_on_reboot)
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+			set_bit(WDOG_STOP_ON_REBOOT, &wdd->status);
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+		else
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+			clear_bit(WDOG_STOP_ON_REBOOT, &wdd->status);
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+	}
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+
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 	if (test_bit(WDOG_STOP_ON_REBOOT, &wdd->status)) {
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 		if (!wdd->ops->stop)
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 			pr_warn("watchdog%d: stop_on_reboot not supported\n", wdd->id);
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@@ -287,14 +308,23 @@
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 int watchdog_register_device(struct watchdog_device *wdd)
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 {
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-	int ret;
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+	const char *dev_str;
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+	int ret = 0;
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 	mutex_lock(&wtd_deferred_reg_mutex);
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 	if (wtd_deferred_reg_done)
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 		ret = __watchdog_register_device(wdd);
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 	else
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-		ret = watchdog_deferred_registration_add(wdd);
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+		watchdog_deferred_registration_add(wdd);
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 	mutex_unlock(&wtd_deferred_reg_mutex);
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+
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+	if (ret) {
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+		dev_str = wdd->parent ? dev_name(wdd->parent) :
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+			  (const char *)wdd->info->identity;
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+		pr_err("%s: failed to register watchdog device (err = %d)\n",
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+			dev_str, ret);
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+	}
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+
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 	return ret;
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 }
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 EXPORT_SYMBOL_GPL(watchdog_register_device);