Adding upstream version 6.8.12.upstream/6.8.12upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

3 files changed, 165 insertions, 64 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 83ba342ae..2f8023934 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1595,12 +1595,15 @@ static struct dyn_ftrace *lookup_rec(unsigned long start, unsigned long end)
 unsigned long ftrace_location_range(unsigned long start, unsigned long end)
 {
 	struct dyn_ftrace *rec;
+	unsigned long ip = 0;
 
+	rcu_read_lock();
 	rec = lookup_rec(start, end);
 	if (rec)
-		return rec->ip;
+		ip = rec->ip;
+	rcu_read_unlock();
 
-	return 0;
+	return ip;
 }
 
 /**
@@ -1613,25 +1616,22 @@ unsigned long ftrace_location_range(unsigned long start, unsigned long end)
  */
 unsigned long ftrace_location(unsigned long ip)
 {
-	struct dyn_ftrace *rec;
+	unsigned long loc;
 	unsigned long offset;
 	unsigned long size;
 
-	rec = lookup_rec(ip, ip);
-	if (!rec) {
+	loc = ftrace_location_range(ip, ip);
+	if (!loc) {
 		if (!kallsyms_lookup_size_offset(ip, &size, &offset))
 			goto out;
 
 		/* map sym+0 to __fentry__ */
 		if (!offset)
-			rec = lookup_rec(ip, ip + size - 1);
+			loc = ftrace_location_range(ip, ip + size - 1);
 	}
 
-	if (rec)
-		return rec->ip;
-
 out:
-	return 0;
+	return loc;
 }
 
 /**
@@ -6593,6 +6593,8 @@ static int ftrace_process_locs(struct module *mod,
 	/* We should have used all pages unless we skipped some */
 	if (pg_unuse) {
 		WARN_ON(!skipped);
+		/* Need to synchronize with ftrace_location_range() */
+		synchronize_rcu();
 		ftrace_free_pages(pg_unuse);
 	}
 	return ret;
@@ -6806,6 +6808,9 @@ void ftrace_release_mod(struct module *mod)
  out_unlock:
 	mutex_unlock(&ftrace_lock);
 
+	/* Need to synchronize with ftrace_location_range() */
+	if (tmp_page)
+		synchronize_rcu();
 	for (pg = tmp_page; pg; pg = tmp_page) {
 
 		/* Needs to be called outside of ftrace_lock */
@@ -7139,6 +7144,7 @@ void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
 	unsigned long start = (unsigned long)(start_ptr);
 	unsigned long end = (unsigned long)(end_ptr);
 	struct ftrace_page **last_pg = &ftrace_pages_start;
+	struct ftrace_page *tmp_page = NULL;
 	struct ftrace_page *pg;
 	struct dyn_ftrace *rec;
 	struct dyn_ftrace key;
@@ -7180,12 +7186,8 @@ void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
 		ftrace_update_tot_cnt--;
 		if (!pg->index) {
 			*last_pg = pg->next;
-			if (pg->records) {
-				free_pages((unsigned long)pg->records, pg->order);
-				ftrace_number_of_pages -= 1 << pg->order;
-			}
-			ftrace_number_of_groups--;
-			kfree(pg);
+			pg->next = tmp_page;
+			tmp_page = pg;
 			pg = container_of(last_pg, struct ftrace_page, next);
 			if (!(*last_pg))
 				ftrace_pages = pg;
@@ -7202,6 +7204,11 @@ void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
 		clear_func_from_hashes(func);
 		kfree(func);
 	}
+	/* Need to synchronize with ftrace_location_range() */
+	if (tmp_page) {
+		synchronize_rcu();
+		ftrace_free_pages(tmp_page);
+	}
 }
 
 void __init ftrace_free_init_mem(void)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index faf56d9a9..943850b25 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1456,6 +1456,11 @@ static void rb_check_bpage(struct ring_buffer_per_cpu *cpu_buffer,
  *
  * As a safety measure we check to make sure the data pages have not
  * been corrupted.
+ *
+ * Callers of this function need to guarantee that the list of pages doesn't get
+ * modified during the check. In particular, if it's possible that the function
+ * is invoked with concurrent readers which can swap in a new reader page then
+ * the caller should take cpu_buffer->reader_lock.
  */
 static void rb_check_pages(struct ring_buffer_per_cpu *cpu_buffer)
 {
@@ -2205,8 +2210,12 @@ int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size,
 		 */
 		synchronize_rcu();
 		for_each_buffer_cpu(buffer, cpu) {
+			unsigned long flags;
+
 			cpu_buffer = buffer->buffers[cpu];
+			raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
 			rb_check_pages(cpu_buffer);
+			raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
 		}
 		atomic_dec(&buffer->record_disabled);
 	}
diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c
index e76f5e1ef..704de62f7 100644
--- a/kernel/trace/trace_events_user.c
+++ b/kernel/trace/trace_events_user.c
@@ -202,6 +202,8 @@ static struct user_event_mm *user_event_mm_get(struct user_event_mm *mm);
 static struct user_event_mm *user_event_mm_get_all(struct user_event *user);
 static void user_event_mm_put(struct user_event_mm *mm);
 static int destroy_user_event(struct user_event *user);
+static bool user_fields_match(struct user_event *user, int argc,
+			      const char **argv);
 
 static u32 user_event_key(char *name)
 {
@@ -1493,17 +1495,24 @@ static int destroy_user_event(struct user_event *user)
 }
 
 static struct user_event *find_user_event(struct user_event_group *group,
-					  char *name, u32 *outkey)
+					  char *name, int argc, const char **argv,
+					  u32 flags, u32 *outkey)
 {
 	struct user_event *user;
 	u32 key = user_event_key(name);
 
 	*outkey = key;
 
-	hash_for_each_possible(group->register_table, user, node, key)
-		if (!strcmp(EVENT_NAME(user), name))
+	hash_for_each_possible(group->register_table, user, node, key) {
+		if (strcmp(EVENT_NAME(user), name))
+			continue;
+
+		if (user_fields_match(user, argc, argv))
 			return user_event_get(user);
 
+		return ERR_PTR(-EADDRINUSE);
+	}
+
 	return NULL;
 }
 
@@ -1860,6 +1869,9 @@ static bool user_fields_match(struct user_event *user, int argc,
 	struct list_head *head = &user->fields;
 	int i = 0;
 
+	if (argc == 0)
+		return list_empty(head);
+
 	list_for_each_entry_reverse(field, head, link) {
 		if (!user_field_match(field, argc, argv, &i))
 			return false;
@@ -1880,10 +1892,8 @@ static bool user_event_match(const char *system, const char *event,
 	match = strcmp(EVENT_NAME(user), event) == 0 &&
 		(!system || strcmp(system, USER_EVENTS_SYSTEM) == 0);
 
-	if (match && argc > 0)
+	if (match)
 		match = user_fields_match(user, argc, argv);
-	else if (match && argc == 0)
-		match = list_empty(&user->fields);
 
 	return match;
 }
@@ -1914,6 +1924,80 @@ static int user_event_trace_register(struct user_event *user)
 }
 
 /*
+ * Counts how many ';' without a trailing space are in the args.
+ */
+static int count_semis_no_space(char *args)
+{
+	int count = 0;
+
+	while ((args = strchr(args, ';'))) {
+		args++;
+
+		if (!isspace(*args))
+			count++;
+	}
+
+	return count;
+}
+
+/*
+ * Copies the arguments while ensuring all ';' have a trailing space.
+ */
+static char *insert_space_after_semis(char *args, int count)
+{
+	char *fixed, *pos;
+	int len;
+
+	len = strlen(args) + count;
+	fixed = kmalloc(len + 1, GFP_KERNEL);
+
+	if (!fixed)
+		return NULL;
+
+	pos = fixed;
+
+	/* Insert a space after ';' if there is no trailing space. */
+	while (*args) {
+		*pos = *args++;
+
+		if (*pos++ == ';' && !isspace(*args))
+			*pos++ = ' ';
+	}
+
+	*pos = '\0';
+
+	return fixed;
+}
+
+static char **user_event_argv_split(char *args, int *argc)
+{
+	char **split;
+	char *fixed;
+	int count;
+
+	/* Count how many ';' without a trailing space */
+	count = count_semis_no_space(args);
+
+	/* No fixup is required */
+	if (!count)
+		return argv_split(GFP_KERNEL, args, argc);
+
+	/* We must fixup 'field;field' to 'field; field' */
+	fixed = insert_space_after_semis(args, count);
+
+	if (!fixed)
+		return NULL;
+
+	/* We do a normal split afterwards */
+	split = argv_split(GFP_KERNEL, fixed, argc);
+
+	/* We can free since argv_split makes a copy */
+	kfree(fixed);
+
+	return split;
+}
+
+/*
  * Parses the event name, arguments and flags then registers if successful.
  * The name buffer lifetime is owned by this method for success cases only.
  * Upon success the returned user_event has its ref count increased by 1.
@@ -1922,11 +2006,11 @@ static int user_event_parse(struct user_event_group *group, char *name,
 			    char *args, char *flags,
 			    struct user_event **newuser, int reg_flags)
 {
-	int ret;
-	u32 key;
 	struct user_event *user;
+	char **argv = NULL;
 	int argc = 0;
-	char **argv;
+	int ret;
+	u32 key;
 
 	/* Currently don't support any text based flags */
 	if (flags != NULL)
@@ -1935,41 +2019,34 @@ static int user_event_parse(struct user_event_group *group, char *name,
 	if (!user_event_capable(reg_flags))
 		return -EPERM;
 
+	if (args) {
+		argv = user_event_argv_split(args, &argc);
+
+		if (!argv)
+			return -ENOMEM;
+	}
+
 	/* Prevent dyn_event from racing */
 	mutex_lock(&event_mutex);
-	user = find_user_event(group, name, &key);
+	user = find_user_event(group, name, argc, (const char **)argv,
+			       reg_flags, &key);
 	mutex_unlock(&event_mutex);
 
-	if (user) {
-		if (args) {
-			argv = argv_split(GFP_KERNEL, args, &argc);
-			if (!argv) {
-				ret = -ENOMEM;
-				goto error;
-			}
+	if (argv)
+		argv_free(argv);
 
-			ret = user_fields_match(user, argc, (const char **)argv);
-			argv_free(argv);
-
-		} else
-			ret = list_empty(&user->fields);
-
-		if (ret) {
-			*newuser = user;
-			/*
-			 * Name is allocated by caller, free it since it already exists.
-			 * Caller only worries about failure cases for freeing.
-			 */
-			kfree(name);
-		} else {
-			ret = -EADDRINUSE;
-			goto error;
-		}
+	if (IS_ERR(user))
+		return PTR_ERR(user);
+
+	if (user) {
+		*newuser = user;
+		/*
+		 * Name is allocated by caller, free it since it already exists.
+		 * Caller only worries about failure cases for freeing.
+		 */
+		kfree(name);
 
 		return 0;
-error:
-		user_event_put(user, false);
-		return ret;
 	}
 
 	user = kzalloc(sizeof(*user), GFP_KERNEL_ACCOUNT);
@@ -2052,25 +2129,33 @@ put_user:
 }
 
 /*
- * Deletes a previously created event if it is no longer being used.
+ * Deletes previously created events if they are no longer being used.
  */
 static int delete_user_event(struct user_event_group *group, char *name)
 {
-	u32 key;
-	struct user_event *user = find_user_event(group, name, &key);
+	struct user_event *user;
+	struct hlist_node *tmp;
+	u32 key = user_event_key(name);
+	int ret = -ENOENT;
 
-	if (!user)
-		return -ENOENT;
+	/* Attempt to delete all event(s) with the name passed in */
+	hash_for_each_possible_safe(group->register_table, user, tmp, node, key) {
+		if (strcmp(EVENT_NAME(user), name))
+			continue;
 
-	user_event_put(user, true);
+		if (!user_event_last_ref(user))
+			return -EBUSY;
 
-	if (!user_event_last_ref(user))
-		return -EBUSY;
+		if (!user_event_capable(user->reg_flags))
+			return -EPERM;
 
-	if (!user_event_capable(user->reg_flags))
-		return -EPERM;
+		ret = destroy_user_event(user);
 
-	return destroy_user_event(user);
+		if (ret)
+			goto out;
+	}
+out:
+	return ret;
 }
 
 /*