From 244b2c5ca8b14627e4a17755e5922221e121c771 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Wed, 09 Oct 2024 06:15:07 +0000
Subject: [PATCH] change system file
---
kernel/kernel/jump_label.c | 264 ++++++++++++++++++++++++++++++++--------------------
1 files changed, 161 insertions(+), 103 deletions(-)
diff --git a/kernel/kernel/jump_label.c b/kernel/kernel/jump_label.c
index 01c6737..4ae693c 100644
--- a/kernel/kernel/jump_label.c
+++ b/kernel/kernel/jump_label.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* jump label support
*
@@ -18,7 +19,7 @@
#include <linux/cpu.h>
#include <asm/sections.h>
-/* mutex to protect coming/going of the the jump_label table */
+/* mutex to protect coming/going of the jump_label table */
static DEFINE_MUTEX(jump_label_mutex);
void jump_label_lock(void)
@@ -36,23 +37,57 @@
const struct jump_entry *jea = a;
const struct jump_entry *jeb = b;
- if (jea->key < jeb->key)
+ /*
+ * Entrires are sorted by 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;
+
+ /*
+ * In the batching mode, entries should also be sorted by the code
+ * inside the already sorted list of entries, enabling a bsearch in
+ * the vector.
+ */
+ if (jump_entry_code(jea) < jump_entry_code(jeb))
+ return -1;
+
+ if (jump_entry_code(jea) > jump_entry_code(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);
@@ -182,13 +217,13 @@
}
EXPORT_SYMBOL_GPL(static_key_disable);
-static void __static_key_slow_dec_cpuslocked(struct static_key *key,
- unsigned long rate_limit,
- struct delayed_work *work)
+static bool static_key_slow_try_dec(struct static_key *key)
{
int val;
- lockdep_assert_cpus_held();
+ val = atomic_fetch_add_unless(&key->enabled, -1, 1);
+ if (val == 1)
+ return false;
/*
* The negative count check is valid even when a negative
@@ -197,66 +232,70 @@
* returns is unbalanced, because all other static_key_slow_inc()
* instances block while the update is in progress.
*/
- val = atomic_fetch_add_unless(&key->enabled, -1, 1);
- if (val != 1) {
- WARN(val < 0, "jump label: negative count!\n");
+ WARN(val < 0, "jump label: negative count!\n");
+ return true;
+}
+
+static void __static_key_slow_dec_cpuslocked(struct static_key *key)
+{
+ lockdep_assert_cpus_held();
+
+ if (static_key_slow_try_dec(key))
return;
- }
jump_label_lock();
- if (atomic_dec_and_test(&key->enabled)) {
- if (rate_limit) {
- atomic_inc(&key->enabled);
- schedule_delayed_work(work, rate_limit);
- } else {
- jump_label_update(key);
- }
- }
+ if (atomic_dec_and_test(&key->enabled))
+ jump_label_update(key);
jump_label_unlock();
}
-static void __static_key_slow_dec(struct static_key *key,
- unsigned long rate_limit,
- struct delayed_work *work)
+static void __static_key_slow_dec(struct static_key *key)
{
cpus_read_lock();
- __static_key_slow_dec_cpuslocked(key, rate_limit, work);
+ __static_key_slow_dec_cpuslocked(key);
cpus_read_unlock();
}
-static void jump_label_update_timeout(struct work_struct *work)
+void jump_label_update_timeout(struct work_struct *work)
{
struct static_key_deferred *key =
container_of(work, struct static_key_deferred, work.work);
- __static_key_slow_dec(&key->key, 0, NULL);
+ __static_key_slow_dec(&key->key);
}
+EXPORT_SYMBOL_GPL(jump_label_update_timeout);
void static_key_slow_dec(struct static_key *key)
{
STATIC_KEY_CHECK_USE(key);
- __static_key_slow_dec(key, 0, NULL);
+ __static_key_slow_dec(key);
}
EXPORT_SYMBOL_GPL(static_key_slow_dec);
void static_key_slow_dec_cpuslocked(struct static_key *key)
{
STATIC_KEY_CHECK_USE(key);
- __static_key_slow_dec_cpuslocked(key, 0, NULL);
+ __static_key_slow_dec_cpuslocked(key);
}
-void static_key_slow_dec_deferred(struct static_key_deferred *key)
+void __static_key_slow_dec_deferred(struct static_key *key,
+ struct delayed_work *work,
+ unsigned long timeout)
{
STATIC_KEY_CHECK_USE(key);
- __static_key_slow_dec(&key->key, key->timeout, &key->work);
-}
-EXPORT_SYMBOL_GPL(static_key_slow_dec_deferred);
-void static_key_deferred_flush(struct static_key_deferred *key)
+ if (static_key_slow_try_dec(key))
+ return;
+
+ schedule_delayed_work(work, timeout);
+}
+EXPORT_SYMBOL_GPL(__static_key_slow_dec_deferred);
+
+void __static_key_deferred_flush(void *key, struct delayed_work *work)
{
STATIC_KEY_CHECK_USE(key);
- flush_delayed_work(&key->work);
+ flush_delayed_work(work);
}
-EXPORT_SYMBOL_GPL(static_key_deferred_flush);
+EXPORT_SYMBOL_GPL(__static_key_deferred_flush);
void jump_label_rate_limit(struct static_key_deferred *key,
unsigned long rl)
@@ -269,22 +308,24 @@
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;
}
static int __jump_label_text_reserved(struct jump_entry *iter_start,
- struct jump_entry *iter_stop, void *start, void *end)
+ struct jump_entry *iter_stop, void *start, void *end, bool init)
{
struct jump_entry *iter;
iter = iter_start;
while (iter < iter_stop) {
- if (addr_conflict(iter, start, end))
- return 1;
+ if (init || !jump_entry_is_init(iter)) {
+ if (addr_conflict(iter, start, end))
+ return 1;
+ }
iter++;
}
@@ -329,16 +370,6 @@
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
@@ -363,30 +394,71 @@
{
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;
}
+static bool jump_label_can_update(struct jump_entry *entry, bool init)
+{
+ /*
+ * Cannot update code that was in an init text area.
+ */
+ if (!init && jump_entry_is_init(entry))
+ return false;
+
+ if (!kernel_text_address(jump_entry_code(entry))) {
+ /*
+ * This skips patching built-in __exit, which
+ * is part of init_section_contains() but is
+ * not part of kernel_text_address().
+ *
+ * Skipping built-in __exit is fine since it
+ * will never be executed.
+ */
+ WARN_ONCE(!jump_entry_is_init(entry),
+ "can't patch jump_label at %pS",
+ (void *)jump_entry_code(entry));
+ return false;
+ }
+
+ return true;
+}
+
+#ifndef HAVE_JUMP_LABEL_BATCH
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))
- 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);
- }
+ if (jump_label_can_update(entry, init))
+ arch_jump_label_transform(entry, jump_label_type(entry));
}
}
+#else
+static void __jump_label_update(struct static_key *key,
+ struct jump_entry *entry,
+ struct jump_entry *stop,
+ bool init)
+{
+ for (; (entry < stop) && (jump_entry_key(entry) == key); entry++) {
+
+ if (!jump_label_can_update(entry, init))
+ continue;
+
+ if (!arch_jump_label_transform_queue(entry, jump_label_type(entry))) {
+ /*
+ * Queue is full: Apply the current queue and try again.
+ */
+ arch_jump_label_transform_apply();
+ BUG_ON(!arch_jump_label_transform_queue(entry, jump_label_type(entry)));
+ }
+ }
+ arch_jump_label_transform_apply();
+}
+#endif
void __init jump_label_init(void)
{
@@ -418,6 +490,9 @@
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;
@@ -430,26 +505,13 @@
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;
@@ -463,7 +525,7 @@
static inline struct static_key_mod *static_key_mod(struct static_key *key)
{
- WARN_ON_ONCE(!(key->type & JUMP_TYPE_LINKED));
+ WARN_ON_ONCE(!static_key_linked(key));
return (struct static_key_mod *)(key->type & ~JUMP_TYPE_MASK);
}
@@ -487,19 +549,25 @@
static int __jump_label_mod_text_reserved(void *start, void *end)
{
struct module *mod;
+ int ret;
preempt_disable();
mod = __module_text_address((unsigned long)start);
WARN_ON_ONCE(__module_text_address((unsigned long)end) != mod);
+ if (!try_module_get(mod))
+ mod = NULL;
preempt_enable();
if (!mod)
return 0;
-
- return __jump_label_text_reserved(mod->jump_entries,
+ ret = __jump_label_text_reserved(mod->jump_entries,
mod->jump_entries + mod->num_jump_entries,
- start, end);
+ start, end, mod->state == MODULE_STATE_COMING);
+
+ module_put(mod);
+
+ return ret;
}
static void __jump_label_mod_update(struct static_key *key)
@@ -522,7 +590,8 @@
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);
}
}
@@ -568,12 +637,15 @@
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;
}
@@ -603,7 +675,7 @@
/* 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;
@@ -623,7 +695,7 @@
key = jump_entry_key(iter);
- if (within_module(iter->key, mod))
+ if (within_module((unsigned long)key, mod))
continue;
/* No memory during module load */
@@ -659,19 +731,6 @@
}
}
-/* 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)
@@ -692,9 +751,6 @@
break;
case MODULE_STATE_GOING:
jump_label_del_module(mod);
- break;
- case MODULE_STATE_LIVE:
- jump_label_invalidate_module_init(mod);
break;
}
@@ -732,8 +788,9 @@
*/
int jump_label_text_reserved(void *start, void *end)
{
+ bool init = system_state < SYSTEM_RUNNING;
int ret = __jump_label_text_reserved(__start___jump_table,
- __stop___jump_table, start, end);
+ __stop___jump_table, start, end, init);
if (ret)
return ret;
@@ -765,7 +822,8 @@
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
--
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