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kernel/jump_label.c
19.8 KB
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/* * jump label support * * Copyright (C) 2009 Jason Baron <jbaron@redhat.com> |
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* Copyright (C) 2011 Peter Zijlstra |
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* */ |
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#include <linux/memory.h> #include <linux/uaccess.h> #include <linux/module.h> #include <linux/list.h> |
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#include <linux/slab.h> #include <linux/sort.h> #include <linux/err.h> |
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#include <linux/static_key.h> |
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#include <linux/jump_label_ratelimit.h> |
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#include <linux/bug.h> |
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#include <linux/cpu.h> |
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#include <asm/sections.h> |
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#ifdef HAVE_JUMP_LABEL |
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/* mutex to protect coming/going of the the jump_label table */ static DEFINE_MUTEX(jump_label_mutex); |
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void jump_label_lock(void) { mutex_lock(&jump_label_mutex); } void jump_label_unlock(void) { mutex_unlock(&jump_label_mutex); } |
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static int jump_label_cmp(const void *a, const void *b) { const struct jump_entry *jea = a; const struct jump_entry *jeb = b; |
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if (jump_entry_key(jea) < jump_entry_key(jeb)) |
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return -1; |
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if (jump_entry_key(jea) > jump_entry_key(jeb)) |
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return 1; return 0; } |
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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; } |
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static void |
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jump_label_sort_entries(struct jump_entry *start, struct jump_entry *stop) |
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{ unsigned long size; |
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void *swapfn = NULL; if (IS_ENABLED(CONFIG_HAVE_ARCH_JUMP_LABEL_RELATIVE)) swapfn = jump_label_swap; |
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size = (((unsigned long)stop - (unsigned long)start) / sizeof(struct jump_entry)); |
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sort(start, size, sizeof(struct jump_entry), jump_label_cmp, swapfn); |
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} |
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static void jump_label_update(struct static_key *key); |
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/* * There are similar definitions for the !HAVE_JUMP_LABEL case in jump_label.h. * The use of 'atomic_read()' requires atomic.h and its problematic for some * kernel headers such as kernel.h and others. Since static_key_count() is not * used in the branch statements as it is for the !HAVE_JUMP_LABEL case its ok * to have it be a function here. Similarly, for 'static_key_enable()' and * 'static_key_disable()', which require bug.h. This should allow jump_label.h * to be included from most/all places for HAVE_JUMP_LABEL. */ int static_key_count(struct static_key *key) { /* * -1 means the first static_key_slow_inc() is in progress. * static_key_enabled() must return true, so return 1 here. */ int n = atomic_read(&key->enabled); return n >= 0 ? n : 1; } EXPORT_SYMBOL_GPL(static_key_count); |
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void static_key_slow_inc_cpuslocked(struct static_key *key) |
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{ |
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int v, v1; |
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STATIC_KEY_CHECK_USE(key); |
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lockdep_assert_cpus_held(); |
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/* * Careful if we get concurrent static_key_slow_inc() calls; * later calls must wait for the first one to _finish_ the * jump_label_update() process. At the same time, however, * the jump_label_update() call below wants to see * static_key_enabled(&key) for jumps to be updated properly. * * So give a special meaning to negative key->enabled: it sends * static_key_slow_inc() down the slow path, and it is non-zero * so it counts as "enabled" in jump_label_update(). Note that * atomic_inc_unless_negative() checks >= 0, so roll our own. */ for (v = atomic_read(&key->enabled); v > 0; v = v1) { v1 = atomic_cmpxchg(&key->enabled, v, v + 1); |
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if (likely(v1 == v)) |
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return; } |
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jump_label_lock(); |
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if (atomic_read(&key->enabled) == 0) { atomic_set(&key->enabled, -1); |
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jump_label_update(key); |
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/* * Ensure that if the above cmpxchg loop observes our positive * value, it must also observe all the text changes. */ atomic_set_release(&key->enabled, 1); |
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} else { atomic_inc(&key->enabled); } |
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jump_label_unlock(); |
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} void static_key_slow_inc(struct static_key *key) { cpus_read_lock(); static_key_slow_inc_cpuslocked(key); |
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cpus_read_unlock(); |
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} |
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EXPORT_SYMBOL_GPL(static_key_slow_inc); |
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void static_key_enable_cpuslocked(struct static_key *key) |
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{ |
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STATIC_KEY_CHECK_USE(key); |
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lockdep_assert_cpus_held(); |
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if (atomic_read(&key->enabled) > 0) { WARN_ON_ONCE(atomic_read(&key->enabled) != 1); return; } |
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jump_label_lock(); if (atomic_read(&key->enabled) == 0) { atomic_set(&key->enabled, -1); jump_label_update(key); |
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/* * See static_key_slow_inc(). */ atomic_set_release(&key->enabled, 1); |
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} jump_label_unlock(); |
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} EXPORT_SYMBOL_GPL(static_key_enable_cpuslocked); void static_key_enable(struct static_key *key) { cpus_read_lock(); static_key_enable_cpuslocked(key); |
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cpus_read_unlock(); } EXPORT_SYMBOL_GPL(static_key_enable); |
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void static_key_disable_cpuslocked(struct static_key *key) |
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{ |
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STATIC_KEY_CHECK_USE(key); |
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lockdep_assert_cpus_held(); |
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if (atomic_read(&key->enabled) != 1) { WARN_ON_ONCE(atomic_read(&key->enabled) != 0); return; } |
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jump_label_lock(); if (atomic_cmpxchg(&key->enabled, 1, 0)) jump_label_update(key); jump_label_unlock(); |
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} EXPORT_SYMBOL_GPL(static_key_disable_cpuslocked); void static_key_disable(struct static_key *key) { cpus_read_lock(); static_key_disable_cpuslocked(key); |
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cpus_read_unlock(); } EXPORT_SYMBOL_GPL(static_key_disable); |
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static void __static_key_slow_dec_cpuslocked(struct static_key *key, |
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unsigned long rate_limit, struct delayed_work *work) |
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{ |
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lockdep_assert_cpus_held(); |
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/* * The negative count check is valid even when a negative * key->enabled is in use by static_key_slow_inc(); a * __static_key_slow_dec() before the first static_key_slow_inc() * returns is unbalanced, because all other static_key_slow_inc() * instances block while the update is in progress. */ |
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if (!atomic_dec_and_mutex_lock(&key->enabled, &jump_label_mutex)) { WARN(atomic_read(&key->enabled) < 0, "jump label: negative count! "); |
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return; |
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} |
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if (rate_limit) { atomic_inc(&key->enabled); schedule_delayed_work(work, rate_limit); |
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} else { |
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jump_label_update(key); |
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} |
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jump_label_unlock(); |
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} static void __static_key_slow_dec(struct static_key *key, unsigned long rate_limit, struct delayed_work *work) { cpus_read_lock(); |
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__static_key_slow_dec_cpuslocked(key, rate_limit, work); |
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cpus_read_unlock(); |
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} |
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static void jump_label_update_timeout(struct work_struct *work) { |
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struct static_key_deferred *key = container_of(work, struct static_key_deferred, work.work); __static_key_slow_dec(&key->key, 0, NULL); |
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} |
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void static_key_slow_dec(struct static_key *key) |
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{ |
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STATIC_KEY_CHECK_USE(key); |
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__static_key_slow_dec(key, 0, NULL); |
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} |
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EXPORT_SYMBOL_GPL(static_key_slow_dec); |
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void static_key_slow_dec_cpuslocked(struct static_key *key) { STATIC_KEY_CHECK_USE(key); __static_key_slow_dec_cpuslocked(key, 0, NULL); } |
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void static_key_slow_dec_deferred(struct static_key_deferred *key) |
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{ |
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STATIC_KEY_CHECK_USE(key); |
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__static_key_slow_dec(&key->key, key->timeout, &key->work); |
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} |
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EXPORT_SYMBOL_GPL(static_key_slow_dec_deferred); |
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void static_key_deferred_flush(struct static_key_deferred *key) { |
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STATIC_KEY_CHECK_USE(key); |
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flush_delayed_work(&key->work); } EXPORT_SYMBOL_GPL(static_key_deferred_flush); |
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void jump_label_rate_limit(struct static_key_deferred *key, |
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unsigned long rl) { |
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STATIC_KEY_CHECK_USE(key); |
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key->timeout = rl; INIT_DELAYED_WORK(&key->work, jump_label_update_timeout); } |
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EXPORT_SYMBOL_GPL(jump_label_rate_limit); |
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static int addr_conflict(struct jump_entry *entry, void *start, void *end) { |
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if (jump_entry_code(entry) <= (unsigned long)end && jump_entry_code(entry) + JUMP_LABEL_NOP_SIZE > (unsigned long)start) |
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return 1; return 0; } |
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static int __jump_label_text_reserved(struct jump_entry *iter_start, struct jump_entry *iter_stop, void *start, void *end) |
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{ |
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struct jump_entry *iter; |
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iter = iter_start; while (iter < iter_stop) { |
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if (addr_conflict(iter, start, end)) return 1; |
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iter++; } |
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return 0; } |
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/* |
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* Update code which is definitely not currently executing. * Architectures which need heavyweight synchronization to modify * running code can override this to make the non-live update case * cheaper. */ |
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void __weak __init_or_module arch_jump_label_transform_static(struct jump_entry *entry, |
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enum jump_label_type type) { |
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arch_jump_label_transform(entry, type); |
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} |
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static inline struct jump_entry *static_key_entries(struct static_key *key) |
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{ |
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WARN_ON_ONCE(key->type & JUMP_TYPE_LINKED); return (struct jump_entry *)(key->type & ~JUMP_TYPE_MASK); |
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} |
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static inline bool static_key_type(struct static_key *key) |
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{ |
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return key->type & JUMP_TYPE_TRUE; } static inline bool static_key_linked(struct static_key *key) { return key->type & JUMP_TYPE_LINKED; } static inline void static_key_clear_linked(struct static_key *key) { key->type &= ~JUMP_TYPE_LINKED; } static inline void static_key_set_linked(struct static_key *key) { key->type |= JUMP_TYPE_LINKED; |
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} |
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/*** * 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 * turn point to 'struct jump_entry' tables. * * The two lower bits of the pointer are used to keep track of which pointer * type is in use and to store the initial branch direction, we use an access * function which preserves these bits. */ static void static_key_set_entries(struct static_key *key, struct jump_entry *entries) { unsigned long type; WARN_ON_ONCE((unsigned long)entries & JUMP_TYPE_MASK); type = key->type & JUMP_TYPE_MASK; key->entries = entries; key->type |= type; } |
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static enum jump_label_type jump_label_type(struct jump_entry *entry) |
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{ |
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struct static_key *key = jump_entry_key(entry); |
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bool enabled = static_key_enabled(key); |
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bool branch = jump_entry_is_branch(entry); |
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/* See the comment in linux/jump_label.h */ return enabled ^ branch; |
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} |
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static void __jump_label_update(struct static_key *key, struct jump_entry *entry, |
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struct jump_entry *stop, bool init) |
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{ for (; (entry < stop) && (jump_entry_key(entry) == key); entry++) { /* |
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* An entry->code of 0 indicates an entry which has been * disabled because it was in an init text area. |
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*/ |
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if (init || !jump_entry_is_init(entry)) { |
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if (kernel_text_address(jump_entry_code(entry))) |
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arch_jump_label_transform(entry, jump_label_type(entry)); else |
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WARN_ONCE(1, "can't patch jump_label at %pS", |
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(void *)jump_entry_code(entry)); |
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} |
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} } |
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void __init jump_label_init(void) |
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{ |
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struct jump_entry *iter_start = __start___jump_table; struct jump_entry *iter_stop = __stop___jump_table; |
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struct static_key *key = NULL; |
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struct jump_entry *iter; |
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/* * Since we are initializing the static_key.enabled field with * with the 'raw' int values (to avoid pulling in atomic.h) in * jump_label.h, let's make sure that is safe. There are only two * cases to check since we initialize to 0 or 1. */ BUILD_BUG_ON((int)ATOMIC_INIT(0) != 0); BUILD_BUG_ON((int)ATOMIC_INIT(1) != 1); |
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if (static_key_initialized) return; |
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cpus_read_lock(); |
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jump_label_lock(); |
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jump_label_sort_entries(iter_start, iter_stop); for (iter = iter_start; iter < iter_stop; iter++) { |
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struct static_key *iterk; |
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/* rewrite NOPs */ if (jump_label_type(iter) == JUMP_LABEL_NOP) arch_jump_label_transform_static(iter, JUMP_LABEL_NOP); |
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if (init_section_contains((void *)jump_entry_code(iter), 1)) jump_entry_set_init(iter); |
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iterk = jump_entry_key(iter); |
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if (iterk == key) |
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continue; |
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key = iterk; |
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static_key_set_entries(key, iter); |
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} |
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static_key_initialized = true; |
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jump_label_unlock(); |
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cpus_read_unlock(); |
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} |
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#ifdef CONFIG_MODULES |
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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); |
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bool branch = jump_entry_is_branch(entry); |
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/* See the comment in linux/jump_label.h */ return type ^ branch; } |
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struct static_key_mod { struct static_key_mod *next; |
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struct jump_entry *entries; struct module *mod; }; |
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static inline struct static_key_mod *static_key_mod(struct static_key *key) { |
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WARN_ON_ONCE(!static_key_linked(key)); |
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return (struct static_key_mod *)(key->type & ~JUMP_TYPE_MASK); } /*** * key->type and key->next are the same via union. * This sets key->next and preserves the type bits. * * See additional comments above static_key_set_entries(). */ static void static_key_set_mod(struct static_key *key, struct static_key_mod *mod) { unsigned long type; WARN_ON_ONCE((unsigned long)mod & JUMP_TYPE_MASK); type = key->type & JUMP_TYPE_MASK; key->next = mod; key->type |= type; } |
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static int __jump_label_mod_text_reserved(void *start, void *end) { struct module *mod; |
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preempt_disable(); |
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mod = __module_text_address((unsigned long)start); |
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WARN_ON_ONCE(__module_text_address((unsigned long)end) != mod); preempt_enable(); |
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if (!mod) return 0; |
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return __jump_label_text_reserved(mod->jump_entries, mod->jump_entries + mod->num_jump_entries, start, end); } |
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static void __jump_label_mod_update(struct static_key *key) |
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{ |
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struct static_key_mod *mod; |
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for (mod = static_key_mod(key); mod; mod = mod->next) { struct jump_entry *stop; struct module *m; /* * NULL if the static_key is defined in a module * that does not use it */ if (!mod->entries) continue; |
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m = mod->mod; if (!m) stop = __stop___jump_table; else stop = m->jump_entries + m->num_jump_entries; |
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__jump_label_update(key, mod->entries, stop, |
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m && m->state == MODULE_STATE_COMING); |
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} } /*** * apply_jump_label_nops - patch module jump labels with arch_get_jump_label_nop() * @mod: module to patch * * Allow for run-time selection of the optimal nops. Before the module * loads patch these with arch_get_jump_label_nop(), which is specified by * the arch specific jump label code. */ void jump_label_apply_nops(struct module *mod) |
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{ |
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498 499 500 501 502 503 504 |
struct jump_entry *iter_start = mod->jump_entries; struct jump_entry *iter_stop = iter_start + mod->num_jump_entries; struct jump_entry *iter; /* if the module doesn't have jump label entries, just return */ if (iter_start == iter_stop) return; |
11276d530
|
505 506 507 508 509 |
for (iter = iter_start; iter < iter_stop; iter++) { /* Only write NOPs for arch_branch_static(). */ if (jump_label_init_type(iter) == JUMP_LABEL_NOP) arch_jump_label_transform_static(iter, JUMP_LABEL_NOP); } |
bf5438fca
|
510 |
} |
d430d3d7e
|
511 |
static int jump_label_add_module(struct module *mod) |
bf5438fca
|
512 |
{ |
d430d3d7e
|
513 514 515 |
struct jump_entry *iter_start = mod->jump_entries; struct jump_entry *iter_stop = iter_start + mod->num_jump_entries; struct jump_entry *iter; |
c5905afb0
|
516 |
struct static_key *key = NULL; |
3821fd35b
|
517 |
struct static_key_mod *jlm, *jlm2; |
bf5438fca
|
518 519 |
/* if the module doesn't have jump label entries, just return */ |
d430d3d7e
|
520 |
if (iter_start == iter_stop) |
bf5438fca
|
521 |
return 0; |
d430d3d7e
|
522 523 524 |
jump_label_sort_entries(iter_start, iter_stop); for (iter = iter_start; iter < iter_stop; iter++) { |
c5905afb0
|
525 |
struct static_key *iterk; |
d430d3d7e
|
526 |
|
194836776
|
527 528 |
if (within_module_init(jump_entry_code(iter), mod)) jump_entry_set_init(iter); |
7dcfd915b
|
529 |
iterk = jump_entry_key(iter); |
c5905afb0
|
530 531 |
if (iterk == key) continue; |
d430d3d7e
|
532 |
|
c5905afb0
|
533 |
key = iterk; |
9ae033aca
|
534 |
if (within_module((unsigned long)key, mod)) { |
3821fd35b
|
535 |
static_key_set_entries(key, iter); |
d430d3d7e
|
536 |
continue; |
bf5438fca
|
537 |
} |
c5905afb0
|
538 |
jlm = kzalloc(sizeof(struct static_key_mod), GFP_KERNEL); |
d430d3d7e
|
539 540 |
if (!jlm) return -ENOMEM; |
3821fd35b
|
541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 |
if (!static_key_linked(key)) { jlm2 = kzalloc(sizeof(struct static_key_mod), GFP_KERNEL); if (!jlm2) { kfree(jlm); return -ENOMEM; } preempt_disable(); jlm2->mod = __module_address((unsigned long)key); preempt_enable(); jlm2->entries = static_key_entries(key); jlm2->next = NULL; static_key_set_mod(key, jlm2); static_key_set_linked(key); } |
d430d3d7e
|
556 557 |
jlm->mod = mod; jlm->entries = iter; |
3821fd35b
|
558 559 560 |
jlm->next = static_key_mod(key); static_key_set_mod(key, jlm); static_key_set_linked(key); |
d430d3d7e
|
561 |
|
11276d530
|
562 563 |
/* Only update if we've changed from our initial state */ if (jump_label_type(iter) != jump_label_init_type(iter)) |
194836776
|
564 |
__jump_label_update(key, iter, iter_stop, true); |
bf5438fca
|
565 |
} |
d430d3d7e
|
566 |
|
bf5438fca
|
567 568 |
return 0; } |
d430d3d7e
|
569 |
static void jump_label_del_module(struct module *mod) |
bf5438fca
|
570 |
{ |
d430d3d7e
|
571 572 573 |
struct jump_entry *iter_start = mod->jump_entries; struct jump_entry *iter_stop = iter_start + mod->num_jump_entries; struct jump_entry *iter; |
c5905afb0
|
574 575 |
struct static_key *key = NULL; struct static_key_mod *jlm, **prev; |
bf5438fca
|
576 |
|
d430d3d7e
|
577 |
for (iter = iter_start; iter < iter_stop; iter++) { |
7dcfd915b
|
578 |
if (jump_entry_key(iter) == key) |
d430d3d7e
|
579 |
continue; |
7dcfd915b
|
580 |
key = jump_entry_key(iter); |
d430d3d7e
|
581 |
|
9ae033aca
|
582 |
if (within_module((unsigned long)key, mod)) |
d430d3d7e
|
583 |
continue; |
3821fd35b
|
584 585 586 |
/* No memory during module load */ if (WARN_ON(!static_key_linked(key))) continue; |
d430d3d7e
|
587 |
prev = &key->next; |
3821fd35b
|
588 |
jlm = static_key_mod(key); |
bf5438fca
|
589 |
|
d430d3d7e
|
590 591 592 593 |
while (jlm && jlm->mod != mod) { prev = &jlm->next; jlm = jlm->next; } |
3821fd35b
|
594 595 596 597 598 599 600 |
/* No memory during module load */ if (WARN_ON(!jlm)) continue; if (prev == &key->next) static_key_set_mod(key, jlm->next); else |
d430d3d7e
|
601 |
*prev = jlm->next; |
3821fd35b
|
602 603 604 605 606 607 608 609 |
kfree(jlm); jlm = static_key_mod(key); /* if only one etry is left, fold it back into the static_key */ if (jlm->next == NULL) { static_key_set_entries(key, jlm->entries); static_key_clear_linked(key); |
d430d3d7e
|
610 |
kfree(jlm); |
bf5438fca
|
611 612 613 614 615 616 617 618 619 620 |
} } } static int jump_label_module_notify(struct notifier_block *self, unsigned long val, void *data) { struct module *mod = data; int ret = 0; |
f2545b2d4
|
621 622 |
cpus_read_lock(); jump_label_lock(); |
bf5438fca
|
623 624 |
switch (val) { case MODULE_STATE_COMING: |
d430d3d7e
|
625 |
ret = jump_label_add_module(mod); |
3821fd35b
|
626 |
if (ret) { |
da260fe12
|
627 628 |
WARN(1, "Failed to allocate memory: jump_label may not work properly. "); |
d430d3d7e
|
629 |
jump_label_del_module(mod); |
3821fd35b
|
630 |
} |
bf5438fca
|
631 632 |
break; case MODULE_STATE_GOING: |
d430d3d7e
|
633 |
jump_label_del_module(mod); |
bf5438fca
|
634 635 |
break; } |
bf5438fca
|
636 |
|
f2545b2d4
|
637 638 |
jump_label_unlock(); cpus_read_unlock(); |
d430d3d7e
|
639 |
return notifier_from_errno(ret); |
bf5438fca
|
640 |
} |
885885f6b
|
641 |
static struct notifier_block jump_label_module_nb = { |
bf5438fca
|
642 |
.notifier_call = jump_label_module_notify, |
d430d3d7e
|
643 |
.priority = 1, /* higher than tracepoints */ |
bf5438fca
|
644 |
}; |
d430d3d7e
|
645 |
static __init int jump_label_init_module(void) |
bf5438fca
|
646 647 648 |
{ return register_module_notifier(&jump_label_module_nb); } |
d430d3d7e
|
649 |
early_initcall(jump_label_init_module); |
bf5438fca
|
650 651 |
#endif /* CONFIG_MODULES */ |
d430d3d7e
|
652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 |
/*** * jump_label_text_reserved - check if addr range is reserved * @start: start text addr * @end: end text addr * * checks if the text addr located between @start and @end * overlaps with any of the jump label patch addresses. Code * that wants to modify kernel text should first verify that * it does not overlap with any of the jump label addresses. * Caller must hold jump_label_mutex. * * returns 1 if there is an overlap, 0 otherwise */ int jump_label_text_reserved(void *start, void *end) { int ret = __jump_label_text_reserved(__start___jump_table, __stop___jump_table, start, end); if (ret) return ret; #ifdef CONFIG_MODULES ret = __jump_label_mod_text_reserved(start, end); #endif return ret; } |
706249c22
|
678 |
static void jump_label_update(struct static_key *key) |
d430d3d7e
|
679 |
{ |
c5905afb0
|
680 |
struct jump_entry *stop = __stop___jump_table; |
3821fd35b
|
681 |
struct jump_entry *entry; |
d430d3d7e
|
682 |
#ifdef CONFIG_MODULES |
bed831f9a
|
683 |
struct module *mod; |
140fe3b1a
|
684 |
|
3821fd35b
|
685 686 687 688 |
if (static_key_linked(key)) { __jump_label_mod_update(key); return; } |
140fe3b1a
|
689 |
|
bed831f9a
|
690 691 |
preempt_disable(); mod = __module_address((unsigned long)key); |
140fe3b1a
|
692 693 |
if (mod) stop = mod->jump_entries + mod->num_jump_entries; |
bed831f9a
|
694 |
preempt_enable(); |
d430d3d7e
|
695 |
#endif |
3821fd35b
|
696 |
entry = static_key_entries(key); |
140fe3b1a
|
697 698 |
/* if there are no users, entry can be NULL */ if (entry) |
194836776
|
699 700 |
__jump_label_update(key, entry, stop, system_state < SYSTEM_RUNNING); |
d430d3d7e
|
701 |
} |
1987c947d
|
702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 |
#ifdef CONFIG_STATIC_KEYS_SELFTEST static DEFINE_STATIC_KEY_TRUE(sk_true); static DEFINE_STATIC_KEY_FALSE(sk_false); static __init int jump_label_test(void) { int i; for (i = 0; i < 2; i++) { WARN_ON(static_key_enabled(&sk_true.key) != true); WARN_ON(static_key_enabled(&sk_false.key) != false); WARN_ON(!static_branch_likely(&sk_true)); WARN_ON(!static_branch_unlikely(&sk_true)); WARN_ON(static_branch_likely(&sk_false)); WARN_ON(static_branch_unlikely(&sk_false)); static_branch_disable(&sk_true); static_branch_enable(&sk_false); WARN_ON(static_key_enabled(&sk_true.key) == true); WARN_ON(static_key_enabled(&sk_false.key) == false); WARN_ON(static_branch_likely(&sk_true)); WARN_ON(static_branch_unlikely(&sk_true)); WARN_ON(!static_branch_likely(&sk_false)); WARN_ON(!static_branch_unlikely(&sk_false)); static_branch_enable(&sk_true); static_branch_disable(&sk_false); } return 0; } |
92ee46efe
|
736 |
early_initcall(jump_label_test); |
1987c947d
|
737 738 739 |
#endif /* STATIC_KEYS_SELFTEST */ #endif /* HAVE_JUMP_LABEL */ |