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authorPeter Zijlstra <peterz@infradead.org>2015-07-24 14:55:40 +0200
committerIngo Molnar <mingo@kernel.org>2015-08-03 11:34:13 +0200
commita1efb01feca597b2abbc89873b40ef8ec6690168 (patch)
treeaf073fc563ab4bcd383999c1adc2313b1a62da48 /kernel/jump_label.c
parent76b235c6bcb16062d663e2ee96db0b69f2e6bc14 (diff)
downloadlinux-sh-a1efb01feca597b2abbc89873b40ef8ec6690168.tar.gz
jump_label, locking/static_keys: Rename JUMP_LABEL_TYPE_* and related helpers to the static_key* pattern
Rename the JUMP_LABEL_TYPE_* macros to be JUMP_TYPE_* and move the inline helpers into kernel/jump_label.c, since that's the only place they're ever used. Also rename the helpers where it's all about static keys. This is the second step in removing the naming confusion that has led to a stream of avoidable bugs such as: a833581e372a ("x86, perf: Fix static_key bug in load_mm_cr4()") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/jump_label.c')
-rw-r--r--kernel/jump_label.c25
1 files changed, 16 insertions, 9 deletions
diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index 96d8945c8bf3..85a2a0086c67 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -56,6 +56,11 @@ jump_label_sort_entries(struct jump_entry *start, struct jump_entry *stop)
static void jump_label_update(struct static_key *key, int enable);
+static inline bool static_key_type(struct static_key *key)
+{
+ return (unsigned long)key->entries & JUMP_TYPE_MASK;
+}
+
void static_key_slow_inc(struct static_key *key)
{
STATIC_KEY_CHECK_USE();
@@ -64,7 +69,7 @@ void static_key_slow_inc(struct static_key *key)
jump_label_lock();
if (atomic_read(&key->enabled) == 0) {
- if (!jump_label_get_branch_default(key))
+ if (!static_key_type(key))
jump_label_update(key, JUMP_LABEL_JMP);
else
jump_label_update(key, JUMP_LABEL_NOP);
@@ -87,7 +92,7 @@ static void __static_key_slow_dec(struct static_key *key,
atomic_inc(&key->enabled);
schedule_delayed_work(work, rate_limit);
} else {
- if (!jump_label_get_branch_default(key))
+ if (!static_key_type(key))
jump_label_update(key, JUMP_LABEL_NOP);
else
jump_label_update(key, JUMP_LABEL_JMP);
@@ -178,15 +183,17 @@ static void __jump_label_update(struct static_key *key,
}
}
-static enum jump_label_type jump_label_type(struct static_key *key)
+static inline struct jump_entry *static_key_entries(struct static_key *key)
{
- bool true_branch = jump_label_get_branch_default(key);
- bool state = static_key_enabled(key);
+ return (struct jump_entry *)((unsigned long)key->entries & ~JUMP_TYPE_MASK);
+}
- if ((!true_branch && state) || (true_branch && !state))
- return JUMP_LABEL_JMP;
+static enum jump_label_type jump_label_type(struct static_key *key)
+{
+ bool enabled = static_key_enabled(key);
+ bool type = static_key_type(key);
- return JUMP_LABEL_NOP;
+ return enabled ^ type;
}
void __init jump_label_init(void)
@@ -442,7 +449,7 @@ int jump_label_text_reserved(void *start, void *end)
static void jump_label_update(struct static_key *key, int enable)
{
struct jump_entry *stop = __stop___jump_table;
- struct jump_entry *entry = jump_label_get_entries(key);
+ struct jump_entry *entry = static_key_entries(key);
#ifdef CONFIG_MODULES
struct module *mod;