[PATCH RFC V4 03/10] jump_label: if a key has already been initialized, don't nop it out

Jeremy Fitzhardinge
2011-10-13T00:08:50Z

From: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

If a key has been enabled before jump_label_init() is called, don't
nop it out.

This removes arch_jump_label_text_poke_early() (which can only nop
out a site) and uses arch_jump_label_transform() instead.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Jason Baron <jbaron@redhat.com>
---
include/linux/jump_label.h | 3 +--
kernel/jump_label.c | 20 ++++++++------------
2 files changed, 9 insertions(+), 14 deletions(-)

diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h
index 1213e9d..12e804e 100644
--- a/include/linux/jump_label.h
+++ b/include/linux/jump_label.h
@@ -44,8 +44,7 @@ extern struct jump_entry __stop___jump_table[];
extern void jump_label_lock(void);
extern void jump_label_unlock(void);
extern void arch_jump_label_transform(struct jump_entry *entry,
- enum jump_label_type type);
-extern void arch_jump_label_text_poke_early(jump_label_t addr);
+ enum jump_label_type type);
extern int jump_label_text_reserved(void *start, void *end);
extern void jump_label_inc(struct jump_label_key *key);
extern void jump_label_dec(struct jump_label_key *key);
diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index a8ce450..059202d5 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -121,13 +121,6 @@ static void __jump_label_update(struct jump_label_key *key,
}
}

-/*
- * Not all archs need this.
- */
-void __weak arch_jump_label_text_poke_early(jump_label_t addr)
-{
-}
-
static __init int jump_label_init(void)
{
struct jump_entry *iter_start = __start___jump_table;
@@ -139,12 +132,15 @@ static __init int jump_label_init(void)
jump_label_sort_entries(iter_start, iter_stop);

for (iter = iter_start; iter < iter_stop; iter++) {
- arch_jump_label_text_poke_early(iter->code);
- if (iter->key == (jump_label_t)(unsigned long)key)
+ struct jump_label_key *iterk;
+
+ iterk = (struct jump_label_key *)(unsigned long)iter->key;
+ arch_jump_label_transform(iter, jump_label_enabled(iterk) ?
+ JUMP_LABEL_ENABLE : JUMP_LABEL_DISABLE);
+ if (iterk == key)
continue;

- key = (struct jump_label_key *)(unsigned long)iter->key;
- atomic_set(&key->enabled, 0);
+ key = iterk;
key->entries = iter;
#ifdef CONFIG_MODULES
key->next = NULL;
@@ -212,7 +208,7 @@ void jump_label_apply_nops(struct module *mod)
return;

for (iter = iter_start; iter < iter_stop; iter++)
- arch_jump_label_text_poke_early(iter->code);
+ arch_jump_label_transform(iter, JUMP_LABEL_DISABLE);
}

static int jump_label_add_module(struct module *mod)
--
1.7.6.4