1 files changed, 120 insertions, 1 deletions

diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 0d2e47370ee7..7da1dfeb322e 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1704,6 +1704,125 @@ __register_event(struct ftrace_event_call *call, struct module *mod)
         return 0;
 }
 
+static char *enum_replace(char *ptr, struct trace_enum_map *map, int len)
+{
+        int rlen;
+        int elen;
+
+        /* Find the length of the enum value as a string */
+        elen = snprintf(ptr, 0, "%ld", map->enum_value);
+        /* Make sure there's enough room to replace the string with the value */
+        if (len < elen)
+                return NULL;
+
+        snprintf(ptr, elen + 1, "%ld", map->enum_value);
+
+        /* Get the rest of the string of ptr */
+        rlen = strlen(ptr + len);
+        memmove(ptr + elen, ptr + len, rlen);
+        /* Make sure we end the new string */
+        ptr[elen + rlen] = 0;
+
+        return ptr + elen;
+}
+
+static void update_event_printk(struct ftrace_event_call *call,
+                                struct trace_enum_map *map)
+{
+        char *ptr;
+        int quote = 0;
+        int len = strlen(map->enum_string);
+
+        for (ptr = call->print_fmt; *ptr; ptr++) {
+                if (*ptr == '\\') {
+                        ptr++;
+                        /* paranoid */
+                        if (!*ptr)
+                                break;
+                        continue;
+                }
+                if (*ptr == '"') {
+                        quote ^= 1;
+                        continue;
+                }
+                if (quote)
+                        continue;
+                if (isdigit(*ptr)) {
+                        /* skip numbers */
+                        do {
+                                ptr++;
+                                /* Check for alpha chars like ULL */
+                        } while (isalnum(*ptr));
+                        /*
+                         * A number must have some kind of delimiter after
+                         * it, and we can ignore that too.
+                         */
+                        continue;
+                }
+                if (isalpha(*ptr) || *ptr == '_') {
+                        if (strncmp(map->enum_string, ptr, len) == 0 &&
+                            !isalnum(ptr[len]) && ptr[len] != '_') {
+                                ptr = enum_replace(ptr, map, len);
+                                /* Hmm, enum string smaller than value */
+                                if (WARN_ON_ONCE(!ptr))
+                                        return;
+                                /*
+                                 * No need to decrement here, as enum_replace()
+                                 * returns the pointer to the character passed
+                                 * the enum, and two enums can not be placed
+                                 * back to back without something in between.
+                                 * We can skip that something in between.
+                                 */
+                                continue;
+                        }
+                skip_more:
+                        do {
+                                ptr++;
+                        } while (isalnum(*ptr) || *ptr == '_');
+                        /*
+                         * If what comes after this variable is a '.' or
+                         * '->' then we can continue to ignore that string.
+                         */
+                        if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) {
+                                ptr += *ptr == '.' ? 1 : 2;
+                                goto skip_more;
+                        }
+                        /*
+                         * Once again, we can skip the delimiter that came
+                         * after the string.
+                         */
+                        continue;
+                }
+        }
+}
+
+void trace_event_enum_update(struct trace_enum_map **map, int len)
+{
+        struct ftrace_event_call *call, *p;
+        const char *last_system = NULL;
+        int last_i;
+        int i;
+
+        down_write(&trace_event_sem);
+        list_for_each_entry_safe(call, p, &ftrace_events, list) {
+                /* events are usually grouped together with systems */
+                if (!last_system || call->class->system != last_system) {
+                        last_i = 0;
+                        last_system = call->class->system;
+                }
+
+                for (i = last_i; i < len; i++) {
+                        if (call->class->system == map[i]->system) {
+                                /* Save the first system if need be */
+                                if (!last_i)
+                                        last_i = i;
+                                update_event_printk(call, map[i]);
+                        }
+                }
+        }
+        up_write(&trace_event_sem);
+}
+
 static struct ftrace_event_file *
 trace_create_new_event(struct ftrace_event_call *call,
                        struct trace_array *tr)
@@ -1915,7 +2034,7 @@ static int trace_module_notify(struct notifier_block *self,
 
 static struct notifier_block trace_module_nb = {
         .notifier_call = trace_module_notify,
-        .priority = 0,
+        .priority = 1, /* higher than trace.c module notify */
 };
 #endif /* CONFIG_MODULES */