5 files changed, 85 insertions, 113 deletions

diff --git a/kernel/trace/rv/reactor_panic.c b/kernel/trace/rv/reactor_panic.c
index 74c6bcc2c749..76537b8a4343 100644
--- a/kernel/trace/rv/reactor_panic.c
+++ b/kernel/trace/rv/reactor_panic.c
@@ -13,13 +13,9 @@
 #include <linux/init.h>
 #include <linux/rv.h>
 
-__printf(1, 2) static void rv_panic_reaction(const char *msg, ...)
+__printf(1, 0) static void rv_panic_reaction(const char *msg, va_list args)
 {
-	va_list args;
-
-	va_start(args, msg);
 	vpanic(msg, args);
-	va_end(args);
 }
 
 static struct rv_reactor rv_panic = {
diff --git a/kernel/trace/rv/reactor_printk.c b/kernel/trace/rv/reactor_printk.c
index 2dae2916c05f..48c934e315b3 100644
--- a/kernel/trace/rv/reactor_printk.c
+++ b/kernel/trace/rv/reactor_printk.c
@@ -12,13 +12,9 @@
 #include <linux/init.h>
 #include <linux/rv.h>
 
-__printf(1, 2) static void rv_printk_reaction(const char *msg, ...)
+__printf(1, 0) static void rv_printk_reaction(const char *msg, va_list args)
 {
-	va_list args;
-
-	va_start(args, msg);
 	vprintk_deferred(msg, args);
-	va_end(args);
 }
 
 static struct rv_reactor rv_printk = {
diff --git a/kernel/trace/rv/rv.c b/kernel/trace/rv/rv.c
index 43e9ea473cda..ee4e68102f17 100644
--- a/kernel/trace/rv/rv.c
+++ b/kernel/trace/rv/rv.c
@@ -375,15 +375,13 @@ static ssize_t monitor_enable_write_data(struct file *filp, const char __user *u
 	if (retval)
 		return retval;
 
-	mutex_lock(&rv_interface_lock);
+	guard(mutex)(&rv_interface_lock);
 
 	if (val)
 		retval = rv_enable_monitor(mon);
 	else
 		retval = rv_disable_monitor(mon);
 
-	mutex_unlock(&rv_interface_lock);
-
 	return retval ? : count;
 }
 
@@ -422,35 +420,27 @@ static const struct file_operations interface_desc_fops = {
 static int create_monitor_dir(struct rv_monitor *mon, struct rv_monitor *parent)
 {
 	struct dentry *root = parent ? parent->root_d : get_monitors_root();
-	const char *name = mon->name;
+	struct dentry *dir __free(rv_remove) = rv_create_dir(mon->name, root);
 	struct dentry *tmp;
 	int retval;
 
-	mon->root_d = rv_create_dir(name, root);
-	if (!mon->root_d)
+	if (!dir)
 		return -ENOMEM;
 
-	tmp = rv_create_file("enable", RV_MODE_WRITE, mon->root_d, mon, &interface_enable_fops);
-	if (!tmp) {
-		retval = -ENOMEM;
-		goto out_remove_root;
-	}
+	tmp = rv_create_file("enable", RV_MODE_WRITE, dir, mon, &interface_enable_fops);
+	if (!tmp)
+		return -ENOMEM;
 
-	tmp = rv_create_file("desc", RV_MODE_READ, mon->root_d, mon, &interface_desc_fops);
-	if (!tmp) {
-		retval = -ENOMEM;
-		goto out_remove_root;
-	}
+	tmp = rv_create_file("desc", RV_MODE_READ, dir, mon, &interface_desc_fops);
+	if (!tmp)
+		return -ENOMEM;
 
-	retval = reactor_populate_monitor(mon);
+	retval = reactor_populate_monitor(mon, dir);
 	if (retval)
-		goto out_remove_root;
+		return retval;
 
+	mon->root_d = no_free_ptr(dir);
 	return 0;
-
-out_remove_root:
-	rv_remove(mon->root_d);
-	return retval;
 }
 
 /*
@@ -568,7 +558,7 @@ static void disable_all_monitors(void)
 	struct rv_monitor *mon;
 	int enabled = 0;
 
-	mutex_lock(&rv_interface_lock);
+	guard(mutex)(&rv_interface_lock);
 
 	list_for_each_entry(mon, &rv_monitors_list, list)
 		enabled += __rv_disable_monitor(mon, false);
@@ -581,8 +571,6 @@ static void disable_all_monitors(void)
 		 */
 		tracepoint_synchronize_unregister();
 	}
-
-	mutex_unlock(&rv_interface_lock);
 }
 
 static int enabled_monitors_open(struct inode *inode, struct file *file)
@@ -623,7 +611,7 @@ static ssize_t enabled_monitors_write(struct file *filp, const char __user *user
 	if (!len)
 		return count;
 
-	mutex_lock(&rv_interface_lock);
+	guard(mutex)(&rv_interface_lock);
 
 	retval = -EINVAL;
 
@@ -644,13 +632,11 @@ static ssize_t enabled_monitors_write(struct file *filp, const char __user *user
 		else
 			retval = rv_disable_monitor(mon);
 
-		if (!retval)
-			retval = count;
-
-		break;
+		if (retval)
+			return retval;
+		return count;
 	}
 
-	mutex_unlock(&rv_interface_lock);
 	return retval;
 }
 
@@ -737,7 +723,7 @@ static ssize_t monitoring_on_write_data(struct file *filp, const char __user *us
 	if (retval)
 		return retval;
 
-	mutex_lock(&rv_interface_lock);
+	guard(mutex)(&rv_interface_lock);
 
 	if (val)
 		turn_monitoring_on_with_reset();
@@ -750,8 +736,6 @@ static ssize_t monitoring_on_write_data(struct file *filp, const char __user *us
 	 */
 	tracepoint_synchronize_unregister();
 
-	mutex_unlock(&rv_interface_lock);
-
 	return count;
 }
 
@@ -784,28 +768,26 @@ int rv_register_monitor(struct rv_monitor *monitor, struct rv_monitor *parent)
 		return -EINVAL;
 	}
 
-	mutex_lock(&rv_interface_lock);
+	guard(mutex)(&rv_interface_lock);
 
 	list_for_each_entry(r, &rv_monitors_list, list) {
 		if (strcmp(monitor->name, r->name) == 0) {
 			pr_info("Monitor %s is already registered\n", monitor->name);
-			retval = -EEXIST;
-			goto out_unlock;
+			return -EEXIST;
 		}
 	}
 
 	if (parent && rv_is_nested_monitor(parent)) {
 		pr_info("Parent monitor %s is already nested, cannot nest further\n",
 			parent->name);
-		retval = -EINVAL;
-		goto out_unlock;
+		return -EINVAL;
 	}
 
 	monitor->parent = parent;
 
 	retval = create_monitor_dir(monitor, parent);
 	if (retval)
-		goto out_unlock;
+		return retval;
 
 	/* keep children close to the parent for easier visualisation */
 	if (parent)
@@ -813,9 +795,7 @@ int rv_register_monitor(struct rv_monitor *monitor, struct rv_monitor *parent)
 	else
 		list_add_tail(&monitor->list, &rv_monitors_list);
 
-out_unlock:
-	mutex_unlock(&rv_interface_lock);
-	return retval;
+	return 0;
 }
 
 /**
@@ -826,13 +806,12 @@ out_unlock:
  */
 int rv_unregister_monitor(struct rv_monitor *monitor)
 {
-	mutex_lock(&rv_interface_lock);
+	guard(mutex)(&rv_interface_lock);
 
 	rv_disable_monitor(monitor);
 	list_del(&monitor->list);
 	destroy_monitor_dir(monitor);
 
-	mutex_unlock(&rv_interface_lock);
 	return 0;
 }
 
@@ -840,39 +819,36 @@ int __init rv_init_interface(void)
 {
 	struct dentry *tmp;
 	int retval;
+	struct dentry *root_dir __free(rv_remove) = rv_create_dir("rv", NULL);
 
-	rv_root.root_dir = rv_create_dir("rv", NULL);
-	if (!rv_root.root_dir)
-		goto out_err;
+	if (!root_dir)
+		return 1;
 
-	rv_root.monitors_dir = rv_create_dir("monitors", rv_root.root_dir);
+	rv_root.monitors_dir = rv_create_dir("monitors", root_dir);
 	if (!rv_root.monitors_dir)
-		goto out_err;
+		return 1;
 
-	tmp = rv_create_file("available_monitors", RV_MODE_READ, rv_root.root_dir, NULL,
+	tmp = rv_create_file("available_monitors", RV_MODE_READ, root_dir, NULL,
 			     &available_monitors_ops);
 	if (!tmp)
-		goto out_err;
+		return 1;
 
-	tmp = rv_create_file("enabled_monitors", RV_MODE_WRITE, rv_root.root_dir, NULL,
+	tmp = rv_create_file("enabled_monitors", RV_MODE_WRITE, root_dir, NULL,
 			     &enabled_monitors_ops);
 	if (!tmp)
-		goto out_err;
+		return 1;
 
-	tmp = rv_create_file("monitoring_on", RV_MODE_WRITE, rv_root.root_dir, NULL,
+	tmp = rv_create_file("monitoring_on", RV_MODE_WRITE, root_dir, NULL,
 			     &monitoring_on_fops);
 	if (!tmp)
-		goto out_err;
-	retval = init_rv_reactors(rv_root.root_dir);
+		return 1;
+	retval = init_rv_reactors(root_dir);
 	if (retval)
-		goto out_err;
+		return 1;
 
 	turn_monitoring_on();
 
-	return 0;
+	rv_root.root_dir = no_free_ptr(root_dir);
 
-out_err:
-	rv_remove(rv_root.root_dir);
-	printk(KERN_ERR "RV: Error while creating the RV interface\n");
-	return 1;
+	return 0;
 }
diff --git a/kernel/trace/rv/rv.h b/kernel/trace/rv/rv.h
index 1485a70c1bf4..2c0f51ff9d5c 100644
--- a/kernel/trace/rv/rv.h
+++ b/kernel/trace/rv/rv.h
@@ -17,6 +17,8 @@ struct rv_interface {
 #define rv_create_file			tracefs_create_file
 #define rv_remove			tracefs_remove
 
+DEFINE_FREE(rv_remove, struct dentry *, if (_T) rv_remove(_T));
+
 #define MAX_RV_MONITOR_NAME_SIZE	32
 #define MAX_RV_REACTOR_NAME_SIZE	32
 
@@ -30,10 +32,10 @@ bool rv_is_container_monitor(struct rv_monitor *mon);
 bool rv_is_nested_monitor(struct rv_monitor *mon);
 
 #ifdef CONFIG_RV_REACTORS
-int reactor_populate_monitor(struct rv_monitor *mon);
+int reactor_populate_monitor(struct rv_monitor *mon, struct dentry *root);
 int init_rv_reactors(struct dentry *root_dir);
 #else
-static inline int reactor_populate_monitor(struct rv_monitor *mon)
+static inline int reactor_populate_monitor(struct rv_monitor *mon, struct dentry *root)
 {
 	return 0;
 }
diff --git a/kernel/trace/rv/rv_reactors.c b/kernel/trace/rv/rv_reactors.c
index d32859fec238..460af07f7aba 100644
--- a/kernel/trace/rv/rv_reactors.c
+++ b/kernel/trace/rv/rv_reactors.c
@@ -61,6 +61,7 @@
  *      printk
  */
 
+#include <linux/lockdep.h>
 #include <linux/slab.h>
 
 #include "rv.h"
@@ -232,9 +233,7 @@ monitor_reactors_write(struct file *file, const char __user *user_buf,
 	seq_f = file->private_data;
 	mon = seq_f->private;
 
-	mutex_lock(&rv_interface_lock);
-
-	retval = -EINVAL;
+	guard(mutex)(&rv_interface_lock);
 
 	list_for_each_entry(reactor, &rv_reactors_list, list) {
 		if (strcmp(ptr, reactor->name) != 0)
@@ -242,13 +241,10 @@ monitor_reactors_write(struct file *file, const char __user *user_buf,
 
 		monitor_swap_reactors(mon, reactor);
 
-		retval = count;
-		break;
+		return count;
 	}
 
-	mutex_unlock(&rv_interface_lock);
-
-	return retval;
+	return -EINVAL;
 }
 
 /*
@@ -309,18 +305,14 @@ static int __rv_register_reactor(struct rv_reactor *reactor)
  */
 int rv_register_reactor(struct rv_reactor *reactor)
 {
-	int retval = 0;
-
 	if (strlen(reactor->name) >= MAX_RV_REACTOR_NAME_SIZE) {
 		pr_info("Reactor %s has a name longer than %d\n",
 			reactor->name, MAX_RV_MONITOR_NAME_SIZE);
 		return -EINVAL;
 	}
 
-	mutex_lock(&rv_interface_lock);
-	retval = __rv_register_reactor(reactor);
-	mutex_unlock(&rv_interface_lock);
-	return retval;
+	guard(mutex)(&rv_interface_lock);
+	return __rv_register_reactor(reactor);
 }
 
 /**
@@ -331,9 +323,8 @@ int rv_register_reactor(struct rv_reactor *reactor)
  */
 int rv_unregister_reactor(struct rv_reactor *reactor)
 {
-	mutex_lock(&rv_interface_lock);
+	guard(mutex)(&rv_interface_lock);
 	list_del(&reactor->list);
-	mutex_unlock(&rv_interface_lock);
 	return 0;
 }
 
@@ -347,7 +338,7 @@ static bool __read_mostly reacting_on;
  *
  * Returns 1 if on, 0 otherwise.
  */
-bool rv_reacting_on(void)
+static bool rv_reacting_on(void)
 {
 	/* Ensures that concurrent monitors read consistent reacting_on */
 	smp_rmb();
@@ -389,7 +380,7 @@ static ssize_t reacting_on_write_data(struct file *filp, const char __user *user
 	if (retval)
 		return retval;
 
-	mutex_lock(&rv_interface_lock);
+	guard(mutex)(&rv_interface_lock);
 
 	if (val)
 		turn_reacting_on();
@@ -402,8 +393,6 @@ static ssize_t reacting_on_write_data(struct file *filp, const char __user *user
 	 */
 	tracepoint_synchronize_unregister();
 
-	mutex_unlock(&rv_interface_lock);
-
 	return count;
 }
 
@@ -416,14 +405,15 @@ static const struct file_operations reacting_on_fops = {
 /**
  * reactor_populate_monitor - creates per monitor reactors file
  * @mon:	The monitor.
+ * @root:	The directory of the monitor.
  *
  * Returns 0 if successful, error otherwise.
  */
-int reactor_populate_monitor(struct rv_monitor *mon)
+int reactor_populate_monitor(struct rv_monitor *mon, struct dentry *root)
 {
 	struct dentry *tmp;
 
-	tmp = rv_create_file("reactors", RV_MODE_WRITE, mon->root_d, mon, &monitor_reactors_ops);
+	tmp = rv_create_file("reactors", RV_MODE_WRITE, root, mon, &monitor_reactors_ops);
 	if (!tmp)
 		return -ENOMEM;
 
@@ -438,7 +428,7 @@ int reactor_populate_monitor(struct rv_monitor *mon)
 /*
  * Nop reactor register
  */
-__printf(1, 2) static void rv_nop_reaction(const char *msg, ...)
+__printf(1, 0) static void rv_nop_reaction(const char *msg, va_list args)
 {
 }
 
@@ -450,30 +440,42 @@ static struct rv_reactor rv_nop = {
 
 int init_rv_reactors(struct dentry *root_dir)
 {
-	struct dentry *available, *reacting;
 	int retval;
 
-	available = rv_create_file("available_reactors", RV_MODE_READ, root_dir, NULL,
-				   &available_reactors_ops);
-	if (!available)
-		goto out_err;
+	struct dentry *available __free(rv_remove) =
+		rv_create_file("available_reactors", RV_MODE_READ, root_dir,
+				NULL, &available_reactors_ops);
+
+	struct dentry *reacting __free(rv_remove) =
+		rv_create_file("reacting_on", RV_MODE_WRITE, root_dir, NULL, &reacting_on_fops);
 
-	reacting = rv_create_file("reacting_on", RV_MODE_WRITE, root_dir, NULL, &reacting_on_fops);
-	if (!reacting)
-		goto rm_available;
+	if (!reacting || !available)
+		return -ENOMEM;
 
 	retval = __rv_register_reactor(&rv_nop);
 	if (retval)
-		goto rm_reacting;
+		return retval;
 
 	turn_reacting_on();
 
+	retain_and_null_ptr(available);
+	retain_and_null_ptr(reacting);
 	return 0;
+}
+
+void rv_react(struct rv_monitor *monitor, const char *msg, ...)
+{
+	static DEFINE_WAIT_OVERRIDE_MAP(rv_react_map, LD_WAIT_FREE);
+	va_list args;
+
+	if (!rv_reacting_on() || !monitor->react)
+		return;
+
+	va_start(args, msg);
+
+	lock_map_acquire_try(&rv_react_map);
+	monitor->react(msg, args);
+	lock_map_release(&rv_react_map);
 
-rm_reacting:
-	rv_remove(reacting);
-rm_available:
-	rv_remove(available);
-out_err:
-	return -ENOMEM;
+	va_end(args);
 }