On Tue, Oct 10, 2017 at 06:56:30PM -0400, Steven Rostedt wrote:
> +/* Without jump labels we don't know how many instances, just assume one */
> +static inline int static_key_instances(struct static_key *key)
> +{
> + return 1;
> +}
That's a tad dodgy.. it works for your current usage, but..
> +int static_key_instances(struct static_key *key)
> +{
> + return jump_label_update(key, true);
> }
That's a bit yuck too :/ But I'm not entirely sure something like the
below is actually better...
---
kernel/jump_label.c | 50 ++++++++++++++++++++++++++++++++++++++++----------
1 file changed, 40 insertions(+), 10 deletions(-)
diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index 0bf2e8f5244a..97286ed6c93d 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -354,9 +354,17 @@ static enum jump_label_type jump_label_type(struct
jump_entry *entry)
return enabled ^ branch;
}
-static void __jump_label_update(struct static_key *key,
- struct jump_entry *entry,
- struct jump_entry *stop)
+typedef void (*jump_label_visit_f)(struct jump_entry *entry, void *data);
+
+void __jump_label_update(struct jump_entry *entry, void *data)
+{
+ arch_jump_label_transform(entry, jump_label_type(entry));
+}
+
+static void
+__jump_label_visit(struct static_key *key, struct jump_entry *entry,
+ struct jump_entry *stop, jump_label_visit_f *visit,
+ void *data)
{
for (; (entry < stop) && (jump_entry_key(entry) == key); entry++) {
/*
@@ -365,7 +373,7 @@ static void __jump_label_update(struct static_key *key,
* init code, see jump_label_invalidate_module_init().
*/
if (entry->code && kernel_text_address(entry->code))
- arch_jump_label_transform(entry,
jump_label_type(entry));
+ visit(entry, data);
}
}
@@ -470,7 +478,8 @@ static int __jump_label_mod_text_reserved(void *start, void
*end)
start, end);
}
-static void __jump_label_mod_update(struct static_key *key)
+static void
+__jump_label_mod_visit(struct static_key *key, jump_label_visit_f visit, void
*data)
{
struct static_key_mod *mod;
@@ -490,7 +499,8 @@ static void __jump_label_mod_update(struct static_key *key)
stop = __stop___jump_table;
else
stop = m->jump_entries + m->num_jump_entries;
- __jump_label_update(key, mod->entries, stop);
+
+ __jump_label_visit(key, mod->entries, stop, visit, data);
}
}
@@ -571,7 +581,7 @@ static int jump_label_add_module(struct module *mod)
/* Only update if we've changed from our initial state */
if (jump_label_type(iter) != jump_label_init_type(iter))
- __jump_label_update(key, iter, iter_stop);
+ __jump_label_visit(key, iter, iter_stop,
__jump_label_update, NULL);
}
return 0;
@@ -711,7 +721,7 @@ int jump_label_text_reserved(void *start, void *end)
return ret;
}
-static void jump_label_update(struct static_key *key)
+static void jump_label_visit(struct static_key *key, jump_label_visit_f visit,
void *data)
{
struct jump_entry *stop = __stop___jump_table;
struct jump_entry *entry;
@@ -719,7 +729,7 @@ static void jump_label_update(struct static_key *key)
struct module *mod;
if (static_key_linked(key)) {
- __jump_label_mod_update(key);
+ __jump_label_mod_visit(key, visit, data);
return;
}
@@ -732,7 +742,27 @@ static void jump_label_update(struct static_key *key)
entry = static_key_entries(key);
/* if there are no users, entry can be NULL */
if (entry)
- __jump_label_update(key, entry, stop);
+ __jump_label_visit(key, entry, stop, visit, data);
+}
+
+static void jump_label_update(struct static_key *key)
+{
+ jump_label_visit(key, __jump_label_update, NULL);
+}
+
+static void __jump_label_count(struct jump_entry *entry, void *data)
+{
+ unsigned int *count = data;
+ count++;
+}
+
+unsigned int static_key_instances(struct static_key *key)
+{
+ unsigned int count = 0;
+
+ jump_label_visit(key, __jump_label_count, &count);
+
+ return count;
}
#ifdef CONFIG_STATIC_KEYS_SELFTEST
