Commit b08d7258 authored by Beau Belgrave's avatar Beau Belgrave Committed by Steven Rostedt (Google)
Browse files

tracing/user_events: Store register flags on events 

Currently we don't have any available flags for user processes to use to
indicate options for user_events. We will soon have a flag to indicate
the event should or should not auto-delete once it's not being used by
anyone.

Add a reg_flags field to user_events and parameters to existing
functions to allow for this in future patches.

Link: https://lkml.kernel.org/r/20230614163336.5797-2-beaub@linux.microsoft.com



Signed-off-by: default avatarBeau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent ed0e0ae0

kernel/trace/trace_events_user.c

+10 −6
Original line number Diff line number Diff line
@@ -87,6 +87,7 @@ struct user_event { 
	struct list_head		validators;

	refcount_t			refcnt;

	int				min_size;

	int				reg_flags;

	char				status;

};
@@ -165,7 +166,7 @@ typedef void (*user_event_func_t) (struct user_event *user, struct iov_iter *i, 


static int user_event_parse(struct user_event_group *group, char *name,

			    char *args, char *flags,

			    struct user_event **newuser);

			    struct user_event **newuser, int reg_flags);



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);
@@ -810,7 +811,8 @@ static struct list_head *user_event_get_fields(struct trace_event_call *call) 
 * Upon success user_event has its ref count increased by 1.

 */

static int user_event_parse_cmd(struct user_event_group *group,

				char *raw_command, struct user_event **newuser)

				char *raw_command, struct user_event **newuser,

				int reg_flags)

{

	char *name = raw_command;

	char *args = strpbrk(name, " ");
@@ -824,7 +826,7 @@ static int user_event_parse_cmd(struct user_event_group *group, 
	if (flags)

		*flags++ = '\0';



	return user_event_parse(group, name, args, flags, newuser);

	return user_event_parse(group, name, args, flags, newuser, reg_flags);

}



static int user_field_array_size(const char *type)
@@ -1588,7 +1590,7 @@ static int user_event_create(const char *raw_command) 


	mutex_lock(&group->reg_mutex);



	ret = user_event_parse_cmd(group, name, &user);

	ret = user_event_parse_cmd(group, name, &user, 0);



	if (!ret)

		refcount_dec(&user->refcnt);
@@ -1751,7 +1753,7 @@ static int user_event_trace_register(struct user_event *user) 
 */

static int user_event_parse(struct user_event_group *group, char *name,

			    char *args, char *flags,

			    struct user_event **newuser)

			    struct user_event **newuser, int reg_flags)

{

	int ret;

	u32 key;
@@ -1846,6 +1848,8 @@ static int user_event_parse(struct user_event_group *group, char *name, 
	if (ret)

		goto put_user_lock;



	user->reg_flags = reg_flags;



	/* Ensure we track self ref and caller ref (2) */

	refcount_set(&user->refcnt, 2);
@@ -2144,7 +2148,7 @@ static long user_events_ioctl_reg(struct user_event_file_info *info, 
		return ret;

	}



	ret = user_event_parse_cmd(info->group, name, &user);

	ret = user_event_parse_cmd(info->group, name, &user, reg.flags);



	if (ret) {

		kfree(name);