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authorIngo Molnar <mingo@kernel.org>2018-10-16 17:30:11 +0200
committerIngo Molnar <mingo@kernel.org>2018-10-16 17:30:11 +0200
commitec57e2f0acb01710cd465bc04495ed03a9e0fea1 (patch)
tree9f45889ba31b750f99fd3d0b625684d9b4cd4f17 /kernel/jump_label.c
parent4766ab5677a2842834f9bc4a21587256a811531c (diff)
parent72a9c673636b779e370983fea08e40f97039b981 (diff)
downloadlinux-ec57e2f0acb01710cd465bc04495ed03a9e0fea1.tar.bz2
Merge branch 'x86/build' into locking/core, to pick up dependent patches and unify jump-label work
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/jump_label.c')
-rw-r--r--kernel/jump_label.c100
1 files changed, 45 insertions, 55 deletions
diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index 966a9e9c0f04..b28028b08d44 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -38,23 +38,43 @@ static int jump_label_cmp(const void *a, const void *b)
const struct jump_entry *jea = a;
const struct jump_entry *jeb = b;
- if (jea->key < jeb->key)
+ if (jump_entry_key(jea) < jump_entry_key(jeb))
return -1;
- if (jea->key > jeb->key)
+ if (jump_entry_key(jea) > jump_entry_key(jeb))
return 1;
return 0;
}
+static void jump_label_swap(void *a, void *b, int size)
+{
+ long delta = (unsigned long)a - (unsigned long)b;
+ struct jump_entry *jea = a;
+ struct jump_entry *jeb = b;
+ struct jump_entry tmp = *jea;
+
+ jea->code = jeb->code - delta;
+ jea->target = jeb->target - delta;
+ jea->key = jeb->key - delta;
+
+ jeb->code = tmp.code + delta;
+ jeb->target = tmp.target + delta;
+ jeb->key = tmp.key + delta;
+}
+
static void
jump_label_sort_entries(struct jump_entry *start, struct jump_entry *stop)
{
unsigned long size;
+ void *swapfn = NULL;
+
+ if (IS_ENABLED(CONFIG_HAVE_ARCH_JUMP_LABEL_RELATIVE))
+ swapfn = jump_label_swap;
size = (((unsigned long)stop - (unsigned long)start)
/ sizeof(struct jump_entry));
- sort(start, size, sizeof(struct jump_entry), jump_label_cmp, NULL);
+ sort(start, size, sizeof(struct jump_entry), jump_label_cmp, swapfn);
}
static void jump_label_update(struct static_key *key);
@@ -266,8 +286,8 @@ EXPORT_SYMBOL_GPL(jump_label_rate_limit);
static int addr_conflict(struct jump_entry *entry, void *start, void *end)
{
- if (entry->code <= (unsigned long)end &&
- entry->code + JUMP_LABEL_NOP_SIZE > (unsigned long)start)
+ if (jump_entry_code(entry) <= (unsigned long)end &&
+ jump_entry_code(entry) + JUMP_LABEL_NOP_SIZE > (unsigned long)start)
return 1;
return 0;
@@ -326,16 +346,6 @@ static inline void static_key_set_linked(struct static_key *key)
key->type |= JUMP_TYPE_LINKED;
}
-static inline struct static_key *jump_entry_key(struct jump_entry *entry)
-{
- return (struct static_key *)((unsigned long)entry->key & ~1UL);
-}
-
-static bool jump_entry_branch(struct jump_entry *entry)
-{
- return (unsigned long)entry->key & 1UL;
-}
-
/***
* A 'struct static_key' uses a union such that it either points directly
* to a table of 'struct jump_entry' or to a linked list of modules which in
@@ -360,7 +370,7 @@ static enum jump_label_type jump_label_type(struct jump_entry *entry)
{
struct static_key *key = jump_entry_key(entry);
bool enabled = static_key_enabled(key);
- bool branch = jump_entry_branch(entry);
+ bool branch = jump_entry_is_branch(entry);
/* See the comment in linux/jump_label.h */
return enabled ^ branch;
@@ -368,19 +378,20 @@ static enum jump_label_type jump_label_type(struct jump_entry *entry)
static void __jump_label_update(struct static_key *key,
struct jump_entry *entry,
- struct jump_entry *stop)
+ struct jump_entry *stop,
+ bool init)
{
for (; (entry < stop) && (jump_entry_key(entry) == key); entry++) {
/*
* An entry->code of 0 indicates an entry which has been
* disabled because it was in an init text area.
*/
- if (entry->code) {
- if (kernel_text_address(entry->code))
+ if (init || !jump_entry_is_init(entry)) {
+ if (kernel_text_address(jump_entry_code(entry)))
arch_jump_label_transform(entry, jump_label_type(entry));
else
WARN_ONCE(1, "can't patch jump_label at %pS",
- (void *)(unsigned long)entry->code);
+ (void *)jump_entry_code(entry));
}
}
}
@@ -415,6 +426,9 @@ void __init jump_label_init(void)
if (jump_label_type(iter) == JUMP_LABEL_NOP)
arch_jump_label_transform_static(iter, JUMP_LABEL_NOP);
+ if (init_section_contains((void *)jump_entry_code(iter), 1))
+ jump_entry_set_init(iter);
+
iterk = jump_entry_key(iter);
if (iterk == key)
continue;
@@ -427,26 +441,13 @@ void __init jump_label_init(void)
cpus_read_unlock();
}
-/* Disable any jump label entries in __init/__exit code */
-void __init jump_label_invalidate_initmem(void)
-{
- struct jump_entry *iter_start = __start___jump_table;
- struct jump_entry *iter_stop = __stop___jump_table;
- struct jump_entry *iter;
-
- for (iter = iter_start; iter < iter_stop; iter++) {
- if (init_section_contains((void *)(unsigned long)iter->code, 1))
- iter->code = 0;
- }
-}
-
#ifdef CONFIG_MODULES
static enum jump_label_type jump_label_init_type(struct jump_entry *entry)
{
struct static_key *key = jump_entry_key(entry);
bool type = static_key_type(key);
- bool branch = jump_entry_branch(entry);
+ bool branch = jump_entry_is_branch(entry);
/* See the comment in linux/jump_label.h */
return type ^ branch;
@@ -519,7 +520,8 @@ 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_update(key, mod->entries, stop,
+ m && m->state == MODULE_STATE_COMING);
}
}
@@ -565,12 +567,15 @@ static int jump_label_add_module(struct module *mod)
for (iter = iter_start; iter < iter_stop; iter++) {
struct static_key *iterk;
+ if (within_module_init(jump_entry_code(iter), mod))
+ jump_entry_set_init(iter);
+
iterk = jump_entry_key(iter);
if (iterk == key)
continue;
key = iterk;
- if (within_module(iter->key, mod)) {
+ if (within_module((unsigned long)key, mod)) {
static_key_set_entries(key, iter);
continue;
}
@@ -600,7 +605,7 @@ 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_update(key, iter, iter_stop, true);
}
return 0;
@@ -620,7 +625,7 @@ static void jump_label_del_module(struct module *mod)
key = jump_entry_key(iter);
- if (within_module(iter->key, mod))
+ if (within_module((unsigned long)key, mod))
continue;
/* No memory during module load */
@@ -656,19 +661,6 @@ static void jump_label_del_module(struct module *mod)
}
}
-/* Disable any jump label entries in module init code */
-static void jump_label_invalidate_module_init(struct module *mod)
-{
- struct jump_entry *iter_start = mod->jump_entries;
- struct jump_entry *iter_stop = iter_start + mod->num_jump_entries;
- struct jump_entry *iter;
-
- for (iter = iter_start; iter < iter_stop; iter++) {
- if (within_module_init(iter->code, mod))
- iter->code = 0;
- }
-}
-
static int
jump_label_module_notify(struct notifier_block *self, unsigned long val,
void *data)
@@ -690,9 +682,6 @@ jump_label_module_notify(struct notifier_block *self, unsigned long val,
case MODULE_STATE_GOING:
jump_label_del_module(mod);
break;
- case MODULE_STATE_LIVE:
- jump_label_invalidate_module_init(mod);
- break;
}
jump_label_unlock();
@@ -762,7 +751,8 @@ 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_update(key, entry, stop,
+ system_state < SYSTEM_RUNNING);
}
#ifdef CONFIG_STATIC_KEYS_SELFTEST