summaryrefslogtreecommitdiffstats
path: root/kernel/trace/trace_events_user.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/trace/trace_events_user.c')
-rw-r--r--kernel/trace/trace_events_user.c102
1 files changed, 90 insertions, 12 deletions
diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c
index 704de62f7a..82b191f33a 100644
--- a/kernel/trace/trace_events_user.c
+++ b/kernel/trace/trace_events_user.c
@@ -34,7 +34,8 @@
/* Limit how long of an event name plus args within the subsystem. */
#define MAX_EVENT_DESC 512
-#define EVENT_NAME(user_event) ((user_event)->tracepoint.name)
+#define EVENT_NAME(user_event) ((user_event)->reg_name)
+#define EVENT_TP_NAME(user_event) ((user_event)->tracepoint.name)
#define MAX_FIELD_ARRAY_SIZE 1024
/*
@@ -54,10 +55,13 @@
* allows isolation for events by various means.
*/
struct user_event_group {
- char *system_name;
- struct hlist_node node;
- struct mutex reg_mutex;
+ char *system_name;
+ char *system_multi_name;
+ struct hlist_node node;
+ struct mutex reg_mutex;
DECLARE_HASHTABLE(register_table, 8);
+ /* ID that moves forward within the group for multi-event names */
+ u64 multi_id;
};
/* Group for init_user_ns mapping, top-most group */
@@ -78,6 +82,7 @@ static unsigned int current_user_events;
*/
struct user_event {
struct user_event_group *group;
+ char *reg_name;
struct tracepoint tracepoint;
struct trace_event_call call;
struct trace_event_class class;
@@ -127,6 +132,8 @@ struct user_event_enabler {
#define ENABLE_BIT(e) ((int)((e)->values & ENABLE_VAL_BIT_MASK))
+#define EVENT_MULTI_FORMAT(f) ((f) & USER_EVENT_REG_MULTI_FORMAT)
+
/* Used for asynchronous faulting in of pages */
struct user_event_enabler_fault {
struct work_struct work;
@@ -330,6 +337,7 @@ out:
static void user_event_group_destroy(struct user_event_group *group)
{
kfree(group->system_name);
+ kfree(group->system_multi_name);
kfree(group);
}
@@ -348,6 +356,11 @@ static char *user_event_group_system_name(void)
return system_name;
}
+static char *user_event_group_system_multi_name(void)
+{
+ return kstrdup(USER_EVENTS_MULTI_SYSTEM, GFP_KERNEL);
+}
+
static struct user_event_group *current_user_event_group(void)
{
return init_group;
@@ -367,6 +380,11 @@ static struct user_event_group *user_event_group_create(void)
if (!group->system_name)
goto error;
+ group->system_multi_name = user_event_group_system_multi_name();
+
+ if (!group->system_multi_name)
+ goto error;
+
mutex_init(&group->reg_mutex);
hash_init(group->register_table);
@@ -1482,6 +1500,11 @@ static int destroy_user_event(struct user_event *user)
hash_del(&user->node);
user_event_destroy_validators(user);
+
+ /* If we have different names, both must be freed */
+ if (EVENT_NAME(user) != EVENT_TP_NAME(user))
+ kfree(EVENT_TP_NAME(user));
+
kfree(user->call.print_fmt);
kfree(EVENT_NAME(user));
kfree(user);
@@ -1504,12 +1527,24 @@ static struct user_event *find_user_event(struct user_event_group *group,
*outkey = key;
hash_for_each_possible(group->register_table, user, node, key) {
+ /*
+ * Single-format events shouldn't return multi-format
+ * events. Callers expect the underlying tracepoint to match
+ * the name exactly in these cases. Only check like-formats.
+ */
+ if (EVENT_MULTI_FORMAT(flags) != EVENT_MULTI_FORMAT(user->reg_flags))
+ continue;
+
if (strcmp(EVENT_NAME(user), name))
continue;
if (user_fields_match(user, argc, argv))
return user_event_get(user);
+ /* Scan others if this is a multi-format event */
+ if (EVENT_MULTI_FORMAT(flags))
+ continue;
+
return ERR_PTR(-EADDRINUSE);
}
@@ -1889,8 +1924,12 @@ static bool user_event_match(const char *system, const char *event,
struct user_event *user = container_of(ev, struct user_event, devent);
bool match;
- match = strcmp(EVENT_NAME(user), event) == 0 &&
- (!system || strcmp(system, USER_EVENTS_SYSTEM) == 0);
+ match = strcmp(EVENT_NAME(user), event) == 0;
+
+ if (match && system) {
+ match = strcmp(system, user->group->system_name) == 0 ||
+ strcmp(system, user->group->system_multi_name) == 0;
+ }
if (match)
match = user_fields_match(user, argc, argv);
@@ -1923,6 +1962,33 @@ static int user_event_trace_register(struct user_event *user)
return ret;
}
+static int user_event_set_tp_name(struct user_event *user)
+{
+ lockdep_assert_held(&user->group->reg_mutex);
+
+ if (EVENT_MULTI_FORMAT(user->reg_flags)) {
+ char *multi_name;
+
+ multi_name = kasprintf(GFP_KERNEL_ACCOUNT, "%s.%llx",
+ user->reg_name, user->group->multi_id);
+
+ if (!multi_name)
+ return -ENOMEM;
+
+ user->call.name = multi_name;
+ user->tracepoint.name = multi_name;
+
+ /* Inc to ensure unique multi-event name next time */
+ user->group->multi_id++;
+ } else {
+ /* Non Multi-format uses register name */
+ user->call.name = user->reg_name;
+ user->tracepoint.name = user->reg_name;
+ }
+
+ return 0;
+}
+
/*
* Counts how many ';' without a trailing space are in the args.
*/
@@ -2059,7 +2125,13 @@ static int user_event_parse(struct user_event_group *group, char *name,
INIT_LIST_HEAD(&user->validators);
user->group = group;
- user->tracepoint.name = name;
+ user->reg_name = name;
+ user->reg_flags = reg_flags;
+
+ ret = user_event_set_tp_name(user);
+
+ if (ret)
+ goto put_user;
ret = user_event_parse_fields(user, args);
@@ -2073,11 +2145,14 @@ static int user_event_parse(struct user_event_group *group, char *name,
user->call.data = user;
user->call.class = &user->class;
- user->call.name = name;
user->call.flags = TRACE_EVENT_FL_TRACEPOINT;
user->call.tp = &user->tracepoint;
user->call.event.funcs = &user_event_funcs;
- user->class.system = group->system_name;
+
+ if (EVENT_MULTI_FORMAT(user->reg_flags))
+ user->class.system = group->system_multi_name;
+ else
+ user->class.system = group->system_name;
user->class.fields_array = user_event_fields_array;
user->class.get_fields = user_event_get_fields;
@@ -2099,8 +2174,6 @@ static int user_event_parse(struct user_event_group *group, char *name,
if (ret)
goto put_user_lock;
- user->reg_flags = reg_flags;
-
if (user->reg_flags & USER_EVENT_REG_PERSIST) {
/* Ensure we track self ref and caller ref (2) */
refcount_set(&user->refcnt, 2);
@@ -2124,6 +2197,11 @@ put_user:
user_event_destroy_fields(user);
user_event_destroy_validators(user);
kfree(user->call.print_fmt);
+
+ /* Caller frees reg_name on error, but not multi-name */
+ if (EVENT_NAME(user) != EVENT_TP_NAME(user))
+ kfree(EVENT_TP_NAME(user));
+
kfree(user);
return ret;
}
@@ -2713,7 +2791,7 @@ static int user_seq_show(struct seq_file *m, void *p)
hash_for_each(group->register_table, i, user, node) {
status = user->status;
- seq_printf(m, "%s", EVENT_NAME(user));
+ seq_printf(m, "%s", EVENT_TP_NAME(user));
if (status != 0)
seq_puts(m, " #");