cregit-Linux how code gets into the kernel

Release 4.17 kernel/jump_label.c

Directory: kernel
/*
 * jump label support
 *
 * Copyright (C) 2009 Jason Baron <jbaron@redhat.com>
 * Copyright (C) 2011 Peter Zijlstra
 *
 */
#include <linux/memory.h>
#include <linux/uaccess.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/sort.h>
#include <linux/err.h>
#include <linux/static_key.h>
#include <linux/jump_label_ratelimit.h>
#include <linux/bug.h>
#include <linux/cpu.h>
#include <asm/sections.h>

#ifdef HAVE_JUMP_LABEL

/* mutex to protect coming/going of the the jump_label table */
static DEFINE_MUTEX(jump_label_mutex);


void jump_label_lock(void) { mutex_lock(&jump_label_mutex); }

Contributors

PersonTokensPropCommitsCommitProp
Jason Baron13100.00%1100.00%
Total13100.00%1100.00%


void jump_label_unlock(void) { mutex_unlock(&jump_label_mutex); }

Contributors

PersonTokensPropCommitsCommitProp
Jason Baron13100.00%1100.00%
Total13100.00%1100.00%


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) return -1; if (jea->key > jeb->key) return 1; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Jason Baron62100.00%1100.00%
Total62100.00%1100.00%


static void jump_label_sort_entries(struct jump_entry *start, struct jump_entry *stop) { unsigned long size; size = (((unsigned long)stop - (unsigned long)start) / sizeof(struct jump_entry)); sort(start, size, sizeof(struct jump_entry), jump_label_cmp, NULL); }

Contributors

PersonTokensPropCommitsCommitProp
Jason Baron61100.00%2100.00%
Total61100.00%2100.00%

static void jump_label_update(struct static_key *key); /* * 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; }

Contributors

PersonTokensPropCommitsCommitProp
Jason Baron31100.00%1100.00%
Total31100.00%1100.00%

EXPORT_SYMBOL_GPL(static_key_count);
void static_key_slow_inc_cpuslocked(struct static_key *key) { int v, v1; STATIC_KEY_CHECK_USE(key); /* * 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); if (likely(v1 == v)) return; } jump_label_lock(); if (atomic_read(&key->enabled) == 0) { atomic_set(&key->enabled, -1); jump_label_update(key); /* * 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); } else { atomic_inc(&key->enabled); } jump_label_unlock(); }

Contributors

PersonTokensPropCommitsCommitProp
Paolo Bonzini8163.78%116.67%
Jason Baron3729.13%116.67%
Marc Zyngier43.15%233.33%
Borislav Petkov32.36%116.67%
Peter Zijlstra21.57%116.67%
Total127100.00%6100.00%


void static_key_slow_inc(struct static_key *key) { cpus_read_lock(); static_key_slow_inc_cpuslocked(key); cpus_read_unlock(); }

Contributors

PersonTokensPropCommitsCommitProp
Marc Zyngier1780.95%150.00%
Paolo Bonzini419.05%150.00%
Total21100.00%2100.00%

EXPORT_SYMBOL_GPL(static_key_slow_inc);
void static_key_enable_cpuslocked(struct static_key *key) { STATIC_KEY_CHECK_USE(key); if (atomic_read(&key->enabled) > 0) { WARN_ON_ONCE(atomic_read(&key->enabled) != 1); return; } jump_label_lock(); if (atomic_read(&key->enabled) == 0) { atomic_set(&key->enabled, -1); jump_label_update(key); /* * See static_key_slow_inc(). */ atomic_set_release(&key->enabled, 1); } jump_label_unlock(); }

Contributors

PersonTokensPropCommitsCommitProp
Paolo Bonzini4954.44%220.00%
Jason Baron2831.11%220.00%
Borislav Petkov33.33%110.00%
Hannes Frederic Sowa22.22%110.00%
Peter Zijlstra22.22%110.00%
Gleb Natapov22.22%110.00%
Marc Zyngier22.22%110.00%
Ingo Molnar22.22%110.00%
Total90100.00%10100.00%

EXPORT_SYMBOL_GPL(static_key_enable_cpuslocked);
void static_key_enable(struct static_key *key) { cpus_read_lock(); static_key_enable_cpuslocked(key); cpus_read_unlock(); }

Contributors

PersonTokensPropCommitsCommitProp
Marc Zyngier1780.95%150.00%
Paolo Bonzini419.05%150.00%
Total21100.00%2100.00%

EXPORT_SYMBOL_GPL(static_key_enable);
void static_key_disable_cpuslocked(struct static_key *key) { STATIC_KEY_CHECK_USE(key); if (atomic_read(&key->enabled) != 1) { WARN_ON_ONCE(atomic_read(&key->enabled) != 0); return; } jump_label_lock(); if (atomic_cmpxchg(&key->enabled, 1, 0)) jump_label_update(key); jump_label_unlock(); }

Contributors

PersonTokensPropCommitsCommitProp
Paolo Bonzini6088.24%240.00%
Jason Baron34.41%120.00%
Borislav Petkov34.41%120.00%
Marc Zyngier22.94%120.00%
Total68100.00%5100.00%

EXPORT_SYMBOL_GPL(static_key_disable_cpuslocked);
void static_key_disable(struct static_key *key) { cpus_read_lock(); static_key_disable_cpuslocked(key); cpus_read_unlock(); }

Contributors

PersonTokensPropCommitsCommitProp
Marc Zyngier1780.95%133.33%
Thomas Gleixner314.29%133.33%
Jason Baron14.76%133.33%
Total21100.00%3100.00%

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) { /* * 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. */ if (!atomic_dec_and_mutex_lock(&key->enabled, &jump_label_mutex)) { WARN(atomic_read(&key->enabled) < 0, "jump label: negative count!\n"); return; } if (rate_limit) { atomic_inc(&key->enabled); schedule_delayed_work(work, rate_limit); } else { jump_label_update(key); } jump_label_unlock(); }

Contributors

PersonTokensPropCommitsCommitProp
Jason Baron4552.94%337.50%
Gleb Natapov3237.65%112.50%
Ingo Molnar55.88%112.50%
Marc Zyngier11.18%112.50%
Peter Zijlstra11.18%112.50%
Paolo Bonzini11.18%112.50%
Total85100.00%8100.00%


static void __static_key_slow_dec(struct static_key *key, unsigned long rate_limit, struct delayed_work *work) { cpus_read_lock(); __static_key_slow_dec_cpuslocked(key, rate_limit, work); cpus_read_unlock(); }

Contributors

PersonTokensPropCommitsCommitProp
Marc Zyngier3085.71%125.00%
Thomas Gleixner38.57%125.00%
Jason Baron12.86%125.00%
Peter Zijlstra12.86%125.00%
Total35100.00%4100.00%


static 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); }

Contributors

PersonTokensPropCommitsCommitProp
Gleb Natapov3792.50%150.00%
Ingo Molnar37.50%150.00%
Total40100.00%2100.00%


void static_key_slow_dec(struct static_key *key) { STATIC_KEY_CHECK_USE(key); __static_key_slow_dec(key, 0, NULL); }

Contributors

PersonTokensPropCommitsCommitProp
Gleb Natapov1666.67%125.00%
Ingo Molnar312.50%125.00%
Borislav Petkov312.50%125.00%
Hannes Frederic Sowa28.33%125.00%
Total24100.00%4100.00%

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); }

Contributors

PersonTokensPropCommitsCommitProp
Peter Zijlstra24100.00%1100.00%
Total24100.00%1100.00%


void static_key_slow_dec_deferred(struct static_key_deferred *key) { STATIC_KEY_CHECK_USE(key); __static_key_slow_dec(&key->key, key->timeout, &key->work); }

Contributors

PersonTokensPropCommitsCommitProp
Gleb Natapov2475.00%125.00%
Ingo Molnar39.38%125.00%
Borislav Petkov39.38%125.00%
Hannes Frederic Sowa26.25%125.00%
Total32100.00%4100.00%

EXPORT_SYMBOL_GPL(static_key_slow_dec_deferred);
void static_key_deferred_flush(struct static_key_deferred *key) { STATIC_KEY_CHECK_USE(key); flush_delayed_work(&key->work); }

Contributors

PersonTokensPropCommitsCommitProp
David Matlack2086.96%150.00%
Borislav Petkov313.04%150.00%
Total23100.00%2100.00%

EXPORT_SYMBOL_GPL(static_key_deferred_flush);
void jump_label_rate_limit(struct static_key_deferred *key, unsigned long rl) { STATIC_KEY_CHECK_USE(key); key->timeout = rl; INIT_DELAYED_WORK(&key->work, jump_label_update_timeout); }

Contributors

PersonTokensPropCommitsCommitProp
Gleb Natapov2982.86%125.00%
Borislav Petkov38.57%125.00%
Hannes Frederic Sowa25.71%125.00%
Ingo Molnar12.86%125.00%
Total35100.00%4100.00%

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) return 1; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Jason Baron49100.00%2100.00%
Total49100.00%2100.00%


static int __jump_label_text_reserved(struct jump_entry *iter_start, struct jump_entry *iter_stop, void *start, void *end) { struct jump_entry *iter; iter = iter_start; while (iter < iter_stop) { if (addr_conflict(iter, start, end)) return 1; iter++; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Jason Baron61100.00%2100.00%
Total61100.00%2100.00%

/* * 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. */
void __weak __init_or_module arch_jump_label_transform_static(struct jump_entry *entry, enum jump_label_type type) { arch_jump_label_transform(entry, type); }

Contributors

PersonTokensPropCommitsCommitProp
Jeremy Fitzhardinge2295.65%150.00%
Peter Zijlstra14.35%150.00%
Total23100.00%2100.00%


static inline struct jump_entry *static_key_entries(struct static_key *key) { WARN_ON_ONCE(key->type & JUMP_TYPE_LINKED); return (struct jump_entry *)(key->type & ~JUMP_TYPE_MASK); }

Contributors

PersonTokensPropCommitsCommitProp
Jason Baron1950.00%360.00%
Peter Zijlstra1436.84%120.00%
Jiri Olsa513.16%120.00%
Total38100.00%5100.00%


static inline bool static_key_type(struct static_key *key) { return key->type & JUMP_TYPE_TRUE; }

Contributors

PersonTokensPropCommitsCommitProp
Peter Zijlstra1789.47%266.67%
Jason Baron210.53%133.33%
Total19100.00%3100.00%


static inline bool static_key_linked(struct static_key *key) { return key->type & JUMP_TYPE_LINKED; }

Contributors

PersonTokensPropCommitsCommitProp
Jason Baron19100.00%1100.00%
Total19100.00%1100.00%


static inline void static_key_clear_linked(struct static_key *key) { key->type &= ~JUMP_TYPE_LINKED; }

Contributors

PersonTokensPropCommitsCommitProp
Jason Baron19100.00%1100.00%
Total19100.00%1100.00%


static inline void static_key_set_linked(struct static_key *key) { key->type |= JUMP_TYPE_LINKED; }

Contributors

PersonTokensPropCommitsCommitProp
Jason Baron18100.00%1100.00%
Total18100.00%1100.00%


static inline struct static_key *jump_entry_key(struct jump_entry *entry) { return (struct static_key *)((unsigned long)entry->key & ~1UL); }

Contributors

PersonTokensPropCommitsCommitProp
Peter Zijlstra33100.00%2100.00%
Total33100.00%2100.00%


static bool jump_entry_branch(struct jump_entry *entry) { return (unsigned long)entry->key & 1UL; }

Contributors

PersonTokensPropCommitsCommitProp
Peter Zijlstra22100.00%2100.00%
Total22100.00%2100.00%

/*** * 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; }

Contributors

PersonTokensPropCommitsCommitProp
Jason Baron51100.00%1100.00%
Total51100.00%1100.00%


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); /* See the comment in linux/jump_label.h */ return enabled ^ branch; }

Contributors

PersonTokensPropCommitsCommitProp
Ingo Molnar2352.27%125.00%
Peter Zijlstra2147.73%375.00%
Total44100.00%4100.00%


static void __jump_label_update(struct static_key *key, struct jump_entry *entry, struct jump_entry *stop) { 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); } } }

Contributors

PersonTokensPropCommitsCommitProp
Peter Zijlstra6671.74%133.33%
Josh Poimboeuf2628.26%266.67%
Total92100.00%3100.00%


void __init jump_label_init(void) { struct jump_entry *iter_start = __start___jump_table; struct jump_entry *iter_stop = __stop___jump_table; struct static_key *key = NULL; struct jump_entry *iter; /* * 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); if (static_key_initialized) return; cpus_read_lock(); jump_label_lock(); jump_label_sort_entries(iter_start, iter_stop); for (iter = iter_start; iter < iter_stop; iter++) { struct static_key *iterk; /* rewrite NOPs */ if (jump_label_type(iter) == JUMP_LABEL_NOP) arch_jump_label_transform_static(iter, JUMP_LABEL_NOP); iterk = jump_entry_key(iter); if (iterk == key) continue; key = iterk; static_key_set_entries(key, iter); } static_key_initialized = true; jump_label_unlock(); cpus_read_unlock(); }

Contributors

PersonTokensPropCommitsCommitProp
Jason Baron9663.58%642.86%
Peter Zijlstra1912.58%214.29%
Jeremy Fitzhardinge1811.92%214.29%
Thomas Gleixner63.97%17.14%
Kevin Hao53.31%17.14%
Hannes Frederic Sowa42.65%17.14%
Ingo Molnar31.99%17.14%
Total151100.00%14100.00%

/* 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; } }

Contributors

PersonTokensPropCommitsCommitProp
Josh Poimboeuf67100.00%3100.00%
Total67100.00%3100.00%

#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); /* See the comment in linux/jump_label.h */ return type ^ branch; }

Contributors

PersonTokensPropCommitsCommitProp
Peter Zijlstra44100.00%1100.00%
Total44100.00%1100.00%

struct static_key_mod { struct static_key_mod *next; struct jump_entry *entries; struct module *mod; };
static inline struct static_key_mod *static_key_mod(struct static_key *key) { WARN_ON_ONCE(!(key->type & JUMP_TYPE_LINKED)); return (struct static_key_mod *)(key->type & ~JUMP_TYPE_MASK); }

Contributors

PersonTokensPropCommitsCommitProp
Jason Baron41100.00%1100.00%
Total41100.00%1100.00%

/*** * 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; }

Contributors

PersonTokensPropCommitsCommitProp
Jason Baron51100.00%1100.00%
Total51100.00%1100.00%


static int __jump_label_mod_text_reserved(void *start, void *end) { struct module *mod; preempt_disable(); mod = __module_text_address((unsigned long)start); WARN_ON_ONCE(__module_text_address((unsigned long)end) != mod); preempt_enable(); if (!mod) return 0; return __jump_label_text_reserved(mod->jump_entries, mod->jump_entries + mod->num_jump_entries, start, end); }

Contributors

PersonTokensPropCommitsCommitProp
Jason Baron6482.05%266.67%
Rusty Russell1417.95%133.33%
Total78100.00%3100.00%


static void __jump_label_mod_update(struct static_key *key) { struct static_key_mod *mod; 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; m = mod->mod; if (!m) stop = __stop___jump_table; else stop = m->jump_entries + m->num_jump_entries; __jump_label_update(key, mod->entries, stop); } }

Contributors

PersonTokensPropCommitsCommitProp
Jason Baron7986.81%350.00%
Peter Zijlstra88.79%116.67%
Jiri Olsa22.20%116.67%
Ingo Molnar22.20%116.67%
Total91100.00%6100.00%

/*** * 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) { 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; 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); } }

Contributors

PersonTokensPropCommitsCommitProp
Jason Baron5978.67%228.57%
Peter Zijlstra1317.33%228.57%
Jeremy Fitzhardinge22.67%228.57%
Steven Rostedt11.33%114.29%
Total75100.00%7100.00%


static int jump_label_add_module(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; struct static_key *key = NULL; struct static_key_mod *jlm, *jlm2; /* if the module doesn't have jump label entries, just return */ if (iter_start == iter_stop) return 0; jump_label_sort_entries(iter_start, iter_stop); for (iter = iter_start; iter < iter_stop; iter++) { struct static_key *iterk; iterk = jump_entry_key(iter); if (iterk == key) continue; key = iterk; if (within_module(iter->key, mod)) { static_key_set_entries(key, iter); continue; } jlm = kzalloc(sizeof(struct static_key_mod), GFP_KERNEL); if (!jlm) return -ENOMEM; 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); } jlm->mod = mod; jlm->entries = iter; jlm->next = static_key_mod(key); static_key_set_mod(key, jlm); static_key_set_linked(key); /* 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); } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Jason Baron25788.01%333.33%
Ingo Molnar217.19%111.11%
Peter Zijlstra134.45%444.44%
Jiri Olsa10.34%111.11%
Total292100.00%9100.00%


static void jump_label_del_module(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; struct static_key *key = NULL; struct static_key_mod *jlm, **prev; for (iter = iter_start; iter < iter_stop; iter++) { if (jump_entry_key(iter) == key) continue; key = jump_entry_key(iter); if (within_module(iter->key, mod)) continue; /* No memory during module load */ if (WARN_ON(!static_key_linked(key))) continue; prev = &key->next; jlm = static_key_mod(key); while (jlm && jlm->mod != mod) { prev = &jlm->next; jlm = jlm->next; } /* No memory during module load */ if (WARN_ON(!jlm)) continue; if (prev == &key->next) static_key_set_mod(key, jlm->next); else *prev = jlm->next; 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); kfree(jlm); } } }

Contributors

PersonTokensPropCommitsCommitProp
Jason Baron21595.13%350.00%
Peter Zijlstra93.98%233.33%
Ingo Molnar20.88%116.67%
Total226100.00%6100.00%

/* 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; } }

Contributors

PersonTokensPropCommitsCommitProp
Jason Baron68100.00%2100.00%
Total68100.00%2100.00%


static int jump_label_module_notify(struct notifier_block *self, unsigned long val, void *data) { struct module *mod = data; int ret = 0; cpus_read_lock(); jump_label_lock(); switch (val) { case MODULE_STATE_COMING: ret = jump_label_add_module(mod); if (ret) { WARN(1, "Failed to allocatote memory: jump_label may not work properly.\n"); jump_label_del_module(mod)