// SPDX-License-Identifier: GPL-2.0-only/* * kernel/lockdep.c * * Runtime locking correctness validator * * Started by Ingo Molnar: * * Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> * Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra * * this code maps all the lock dependencies as they occur in a live kernel * and will warn about the following classes of locking bugs: * * - lock inversion scenarios * - circular lock dependencies * - hardirq/softirq safe/unsafe locking bugs * * Bugs are reported even if the current locking scenario does not cause * any deadlock at this point. * * I.e. if anytime in the past two locks were taken in a different order, * even if it happened for another task, even if those were different * locks (but of the same class as this lock), this code will detect it. * * Thanks to Arjan van de Ven for coming up with the initial idea of * mapping lock dependencies runtime. */#define DISABLE_BRANCH_PROFILING#include <linux/mutex.h>#include <linux/sched.h>#include <linux/sched/clock.h>#include <linux/sched/task.h>#include <linux/sched/mm.h>#include <linux/delay.h>#include <linux/module.h>#include <linux/proc_fs.h>#include <linux/seq_file.h>#include <linux/spinlock.h>#include <linux/kallsyms.h>#include <linux/interrupt.h>#include <linux/stacktrace.h>#include <linux/debug_locks.h>#include <linux/irqflags.h>#include <linux/utsname.h>#include <linux/hash.h>#include <linux/ftrace.h>#include <linux/stringify.h>#include <linux/bitmap.h>#include <linux/bitops.h>#include <linux/gfp.h>#include <linux/random.h>#include <linux/jhash.h>#include <linux/nmi.h>#include <linux/rcupdate.h>#include <linux/kprobes.h> #include <asm/sections.h> #include "lockdep_internals.h" #define CREATE_TRACE_POINTS#include <trace/events/lock.h> #ifdef CONFIG_PROVE_LOCKINGint prove_locking = 1;module_param(prove_locking, int, 0644);#else#define prove_locking 0#endif #ifdef CONFIG_LOCK_STATint lock_stat = 1;module_param(lock_stat, int, 0644);#else#define lock_stat 0#endif /* * lockdep_lock: protects the lockdep graph, the hashes and the * class/list/hash allocators. * * This is one of the rare exceptions where it's justified * to use a raw spinlock - we really dont want the spinlock * code to recurse back into the lockdep code... */static arch_spinlock_t __lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;static struct task_struct *__owner; static inline void lockdep_lock(void){ DEBUG_LOCKS_WARN_ON(!irqs_disabled()); arch_spin_lock(&__lock); __owner = current; current->lockdep_recursion++;} static inline void lockdep_unlock(void){ if (debug_locks && DEBUG_LOCKS_WARN_ON(__owner != current)) return; current->lockdep_recursion--; __owner = NULL; arch_spin_unlock(&__lock);} static inline bool lockdep_assert_locked(void){ return DEBUG_LOCKS_WARN_ON(__owner != current);} static struct task_struct *lockdep_selftest_task_struct; static int graph_lock(void){ lockdep_lock(); /* * Make sure that if another CPU detected a bug while * walking the graph we dont change it (while the other * CPU is busy printing out stuff with the graph lock * dropped already) */ if (!debug_locks) { lockdep_unlock(); return 0; } return 1;} static inline void graph_unlock(void){ lockdep_unlock();} /* * Turn lock debugging off and return with 0 if it was off already, * and also release the graph lock: */static inline int debug_locks_off_graph_unlock(void){ int ret = debug_locks_off(); lockdep_unlock(); return ret;} unsigned long nr_list_entries;static struct lock_list list_entries[MAX_LOCKDEP_ENTRIES];static DECLARE_BITMAP(list_entries_in_use, MAX_LOCKDEP_ENTRIES); /* * All data structures here are protected by the global debug_lock. * * nr_lock_classes is the number of elements of lock_classes[] that is * in use. */#define KEYHASH_BITS (MAX_LOCKDEP_KEYS_BITS - 1)#define KEYHASH_SIZE (1UL << KEYHASH_BITS)static struct hlist_head lock_keys_hash[KEYHASH_SIZE];unsigned long nr_lock_classes;unsigned long nr_zapped_classes;#ifndef CONFIG_DEBUG_LOCKDEPstatic#endifstruct lock_class lock_classes[MAX_LOCKDEP_KEYS];static DECLARE_BITMAP(lock_classes_in_use, MAX_LOCKDEP_KEYS); static inline struct lock_class *hlock_class(struct held_lock *hlock){ unsigned int class_idx = hlock->class_idx; /* Don't re-read hlock->class_idx, can't use READ_ONCE() on bitfield */ barrier(); if (!test_bit(class_idx, lock_classes_in_use)) { /* * Someone passed in garbage, we give up. */ DEBUG_LOCKS_WARN_ON(1); return NULL; } /* * At this point, if the passed hlock->class_idx is still garbage, * we just have to live with it */ return lock_classes + class_idx;} #ifdef CONFIG_LOCK_STATstatic DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS], cpu_lock_stats); static inline u64 lockstat_clock(void){ return local_clock();} static int lock_point(unsigned long points[], unsigned long ip){ int i; for (i = 0; i < LOCKSTAT_POINTS; i++) { if (points[i] == 0) { points[i] = ip; break; } if (points[i] == ip) break; } return i;} static void lock_time_inc(struct lock_time *lt, u64 time){ if (time > lt->max) lt->max = time; if (time < lt->min || !lt->nr) lt->min = time; lt->total += time; lt->nr++;} static inline void lock_time_add(struct lock_time *src, struct lock_time *dst){ if (!src->nr) return; if (src->max > dst->max) dst->max = src->max; if (src->min < dst->min || !dst->nr) dst->min = src->min; dst->total += src->total; dst->nr += src->nr;} struct lock_class_stats lock_stats(struct lock_class *class){ struct lock_class_stats stats; int cpu, i; memset(&stats, 0, sizeof(struct lock_class_stats)); for_each_possible_cpu(cpu) { struct lock_class_stats *pcs = &per_cpu(cpu_lock_stats, cpu)[class - lock_classes]; for (i = 0; i < ARRAY_SIZE(stats.contention_point); i++) stats.contention_point[i] += pcs->contention_point[i]; for (i = 0; i < ARRAY_SIZE(stats.contending_point); i++) stats.contending_point[i] += pcs->contending_point[i]; lock_time_add(&pcs->read_waittime, &stats.read_waittime); lock_time_add(&pcs->write_waittime, &stats.write_waittime); lock_time_add(&pcs->read_holdtime, &stats.read_holdtime); lock_time_add(&pcs->write_holdtime, &stats.write_holdtime); for (i = 0; i < ARRAY_SIZE(stats.bounces); i++) stats.bounces[i] += pcs->bounces[i]; } return stats;} void clear_lock_stats(struct lock_class *class){ int cpu; for_each_possible_cpu(cpu) { struct lock_class_stats *cpu_stats = &per_cpu(cpu_lock_stats, cpu)[class - lock_classes]; memset(cpu_stats, 0, sizeof(struct lock_class_stats)); } memset(class->contention_point, 0, sizeof(class->contention_point)); memset(class->contending_point, 0, sizeof(class->contending_point));} static struct lock_class_stats *get_lock_stats(struct lock_class *class){ return &this_cpu_ptr(cpu_lock_stats)[class - lock_classes];} static void lock_release_holdtime(struct held_lock *hlock){ struct lock_class_stats *stats; u64 holdtime; if (!lock_stat) return; holdtime = lockstat_clock() - hlock->holdtime_stamp; stats = get_lock_stats(hlock_class(hlock)); if (hlock->read) lock_time_inc(&stats->read_holdtime, holdtime); else lock_time_inc(&stats->write_holdtime, holdtime);}#elsestatic inline void lock_release_holdtime(struct held_lock *hlock){}#endif /* * We keep a global list of all lock classes. The list is only accessed with * the lockdep spinlock lock held. free_lock_classes is a list with free * elements. These elements are linked together by the lock_entry member in * struct lock_class. */LIST_HEAD(all_lock_classes);static LIST_HEAD(free_lock_classes); /** * struct pending_free - information about data structures about to be freed * @zapped: Head of a list with struct lock_class elements. * @lock_chains_being_freed: Bitmap that indicates which lock_chains[] elements * are about to be freed. */struct pending_free { struct list_head zapped; DECLARE_BITMAP(lock_chains_being_freed, MAX_LOCKDEP_CHAINS);}; /** * struct delayed_free - data structures used for delayed freeing * * A data structure for delayed freeing of data structures that may be * accessed by RCU readers at the time these were freed. * * @rcu_head: Used to schedule an RCU callback for freeing data structures. * @index: Index of @pf to which freed data structures are added. * @scheduled: Whether or not an RCU callback has been scheduled. * @pf: Array with information about data structures about to be freed. */static struct delayed_free { struct rcu_head rcu_head; int index; int scheduled; struct pending_free pf[2];} delayed_free; /* * The lockdep classes are in a hash-table as well, for fast lookup: */#define CLASSHASH_BITS (MAX_LOCKDEP_KEYS_BITS - 1)#define CLASSHASH_SIZE (1UL << CLASSHASH_BITS)#define __classhashfn(key) hash_long((unsigned long)key, CLASSHASH_BITS)#define classhashentry(key) (classhash_table + __classhashfn((key))) static struct hlist_head classhash_table[CLASSHASH_SIZE]; /* * We put the lock dependency chains into a hash-table as well, to cache * their existence: */#define CHAINHASH_BITS (MAX_LOCKDEP_CHAINS_BITS-1)#define CHAINHASH_SIZE (1UL << CHAINHASH_BITS)#define __chainhashfn(chain) hash_long(chain, CHAINHASH_BITS)#define chainhashentry(chain) (chainhash_table + __chainhashfn((chain))) static struct hlist_head chainhash_table[CHAINHASH_SIZE]; /* * The hash key of the lock dependency chains is a hash itself too: * it's a hash of all locks taken up to that lock, including that lock. * It's a 64-bit hash, because it's important for the keys to be * unique. */static inline u64 iterate_chain_key(u64 key, u32 idx){ u32 k0 = key, k1 = key >> 32; __jhash_mix(idx, k0, k1); /* Macro that modifies arguments! */ return k0 | (u64)k1 << 32;} void lockdep_init_task(struct task_struct *task){ task->lockdep_depth = 0; /* no locks held yet */ task->curr_chain_key = INITIAL_CHAIN_KEY; task->lockdep_recursion = 0;} static __always_inline void lockdep_recursion_finish(void){ if (WARN_ON_ONCE((--current->lockdep_recursion) & LOCKDEP_RECURSION_MASK)) current->lockdep_recursion = 0;} void lockdep_set_selftest_task(struct task_struct *task){ lockdep_selftest_task_struct = task;} /* * Debugging switches: */ #define VERBOSE 0#define VERY_VERBOSE 0 #if VERBOSE# define HARDIRQ_VERBOSE 1# define SOFTIRQ_VERBOSE 1#else# define HARDIRQ_VERBOSE 0# define SOFTIRQ_VERBOSE 0#endif #if VERBOSE || HARDIRQ_VERBOSE || SOFTIRQ_VERBOSE/* * Quick filtering for interesting events: */static int class_filter(struct lock_class *class){#if 0 /* Example */ if (class->name_version == 1 && !strcmp(class->name, "lockname")) return 1; if (class->name_version == 1 && !strcmp(class->name, "&struct->lockfield")) return 1;#endif /* Filter everything else. 1 would be to allow everything else */ return 0;}#endif static int verbose(struct lock_class *class){#if VERBOSE return class_filter(class);#endif return 0;} static void print_lockdep_off(const char *bug_msg){ printk(KERN_DEBUG "%s\n", bug_msg); printk(KERN_DEBUG "turning off the locking correctness validator.\n");#ifdef CONFIG_LOCK_STAT printk(KERN_DEBUG "Please attach the output of /proc/lock_stat to the bug report\n");#endif} unsigned long nr_stack_trace_entries; #ifdef CONFIG_PROVE_LOCKING/** * struct lock_trace - single stack backtrace * @hash_entry: Entry in a stack_trace_hash[] list. * @hash: jhash() of @entries. * @nr_entries: Number of entries in @entries. * @entries: Actual stack backtrace. */struct lock_trace { struct hlist_node hash_entry; u32 hash; u32 nr_entries; unsigned long entries[] __aligned(sizeof(unsigned long));};#define LOCK_TRACE_SIZE_IN_LONGS \ (sizeof(struct lock_trace) / sizeof(unsigned long))/* * Stack-trace: sequence of lock_trace structures. Protected by the graph_lock. */static unsigned long stack_trace[MAX_STACK_TRACE_ENTRIES];static struct hlist_head stack_trace_hash[STACK_TRACE_HASH_SIZE]; static bool traces_identical(struct lock_trace *t1, struct lock_trace *t2){ return t1->hash == t2->hash && t1->nr_entries == t2->nr_entries && memcmp(t1->entries, t2->entries, t1->nr_entries * sizeof(t1->entries[0])) == 0;} static struct lock_trace *save_trace(void){ struct lock_trace *trace, *t2; struct hlist_head *hash_head; u32 hash; int max_entries; BUILD_BUG_ON_NOT_POWER_OF_2(STACK_TRACE_HASH_SIZE); BUILD_BUG_ON(LOCK_TRACE_SIZE_IN_LONGS >= MAX_STACK_TRACE_ENTRIES); trace = (struct lock_trace *)(stack_trace + nr_stack_trace_entries);Lines 1–500 of 5928. Load more
// SPDX-License-Identifier: GPL-2.0-only /* * kernel/lockdep.c * * Runtime locking correctness validator * * Started by Ingo Molnar: * * Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> * Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra * * this code maps all the lock dependencies as they occur in a live kernel * and will warn about the following classes of locking bugs: * * - lock inversion scenarios * - circular lock dependencies * - hardirq/softirq safe/unsafe locking bugs * * Bugs are reported even if the current locking scenario does not cause * any deadlock at this point. * * I.e. if anytime in the past two locks were taken in a different order, * even if it happened for another task, even if those were different * locks (but of the same class as this lock), this code will detect it. * * Thanks to Arjan van de Ven for coming up with the initial idea of * mapping lock dependencies runtime. */ #define DISABLE_BRANCH_PROFILING #include <linux/mutex.h> #include <linux/sched.h> #include <linux/sched/clock.h> #include <linux/sched/task.h> #include <linux/sched/mm.h> #include <linux/delay.h> #include <linux/module.h> #include <linux/proc_fs.h> #include <linux/seq_file.h> #include <linux/spinlock.h> #include <linux/kallsyms.h> #include <linux/interrupt.h> #include <linux/stacktrace.h> #include <linux/debug_locks.h> #include <linux/irqflags.h> #include <linux/utsname.h> #include <linux/hash.h> #include <linux/ftrace.h> #include <linux/stringify.h> #include <linux/bitmap.h> #include <linux/bitops.h> #include <linux/gfp.h> #include <linux/random.h> #include <linux/jhash.h> #include <linux/nmi.h> #include <linux/rcupdate.h> #include <linux/kprobes.h> #include <asm/sections.h> #include "lockdep_internals.h" #define CREATE_TRACE_POINTS #include <trace/events/lock.h> #ifdef CONFIG_PROVE_LOCKING int prove_locking = 1; module_param(prove_locking, int, 0644); #else #define prove_locking 0 #endif #ifdef CONFIG_LOCK_STAT int lock_stat = 1; module_param(lock_stat, int, 0644); #else #define lock_stat 0 #endif /* * lockdep_lock: protects the lockdep graph, the hashes and the * class/list/hash allocators. * * This is one of the rare exceptions where it's justified * to use a raw spinlock - we really dont want the spinlock * code to recurse back into the lockdep code... */ static arch_spinlock_t __lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; static struct task_struct *__owner; static inline void lockdep_lock(void) { DEBUG_LOCKS_WARN_ON(!irqs_disabled()); arch_spin_lock(&__lock); __owner = current; current->lockdep_recursion++; } static inline void lockdep_unlock(void) { if (debug_locks && DEBUG_LOCKS_WARN_ON(__owner != current)) return; current->lockdep_recursion--; __owner = NULL; arch_spin_unlock(&__lock); } static inline bool lockdep_assert_locked(void) { return DEBUG_LOCKS_WARN_ON(__owner != current); } static struct task_struct *lockdep_selftest_task_struct; static int graph_lock(void) { lockdep_lock(); /* * Make sure that if another CPU detected a bug while * walking the graph we dont change it (while the other * CPU is busy printing out stuff with the graph lock * dropped already) */ if (!debug_locks) { lockdep_unlock(); return 0; } return 1; } static inline void graph_unlock(void) { lockdep_unlock(); } /* * Turn lock debugging off and return with 0 if it was off already, * and also release the graph lock: */ static inline int debug_locks_off_graph_unlock(void) { int ret = debug_locks_off(); lockdep_unlock(); return ret; } unsigned long nr_list_entries; static struct lock_list list_entries[MAX_LOCKDEP_ENTRIES]; static DECLARE_BITMAP(list_entries_in_use, MAX_LOCKDEP_ENTRIES); /* * All data structures here are protected by the global debug_lock. * * nr_lock_classes is the number of elements of lock_classes[] that is * in use. */ #define KEYHASH_BITS (MAX_LOCKDEP_KEYS_BITS - 1) #define KEYHASH_SIZE (1UL << KEYHASH_BITS) static struct hlist_head lock_keys_hash[KEYHASH_SIZE]; unsigned long nr_lock_classes; unsigned long nr_zapped_classes; #ifndef CONFIG_DEBUG_LOCKDEP static #endif struct lock_class lock_classes[MAX_LOCKDEP_KEYS]; static DECLARE_BITMAP(lock_classes_in_use, MAX_LOCKDEP_KEYS); static inline struct lock_class *hlock_class(struct held_lock *hlock) { unsigned int class_idx = hlock->class_idx; /* Don't re-read hlock->class_idx, can't use READ_ONCE() on bitfield */ barrier(); if (!test_bit(class_idx, lock_classes_in_use)) { /* * Someone passed in garbage, we give up. */ DEBUG_LOCKS_WARN_ON(1); return NULL; } /* * At this point, if the passed hlock->class_idx is still garbage, * we just have to live with it */ return lock_classes + class_idx; } #ifdef CONFIG_LOCK_STAT static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS], cpu_lock_stats); static inline u64 lockstat_clock(void) { return local_clock(); } static int lock_point(unsigned long points[], unsigned long ip) { int i; for (i = 0; i < LOCKSTAT_POINTS; i++) { if (points[i] == 0) { points[i] = ip; break; } if (points[i] == ip) break; } return i; } static void lock_time_inc(struct lock_time *lt, u64 time) { if (time > lt->max) lt->max = time; if (time < lt->min || !lt->nr) lt->min = time; lt->total += time; lt->nr++; } static inline void lock_time_add(struct lock_time *src, struct lock_time *dst) { if (!src->nr) return; if (src->max > dst->max) dst->max = src->max; if (src->min < dst->min || !dst->nr) dst->min = src->min; dst->total += src->total; dst->nr += src->nr; } struct lock_class_stats lock_stats(struct lock_class *class) { struct lock_class_stats stats; int cpu, i; memset(&stats, 0, sizeof(struct lock_class_stats)); for_each_possible_cpu(cpu) { struct lock_class_stats *pcs = &per_cpu(cpu_lock_stats, cpu)[class - lock_classes]; for (i = 0; i < ARRAY_SIZE(stats.contention_point); i++) stats.contention_point[i] += pcs->contention_point[i]; for (i = 0; i < ARRAY_SIZE(stats.contending_point); i++) stats.contending_point[i] += pcs->contending_point[i]; lock_time_add(&pcs->read_waittime, &stats.read_waittime); lock_time_add(&pcs->write_waittime, &stats.write_waittime); lock_time_add(&pcs->read_holdtime, &stats.read_holdtime); lock_time_add(&pcs->write_holdtime, &stats.write_holdtime); for (i = 0; i < ARRAY_SIZE(stats.bounces); i++) stats.bounces[i] += pcs->bounces[i]; } return stats; } void clear_lock_stats(struct lock_class *class) { int cpu; for_each_possible_cpu(cpu) { struct lock_class_stats *cpu_stats = &per_cpu(cpu_lock_stats, cpu)[class - lock_classes]; memset(cpu_stats, 0, sizeof(struct lock_class_stats)); } memset(class->contention_point, 0, sizeof(class->contention_point)); memset(class->contending_point, 0, sizeof(class->contending_point)); } static struct lock_class_stats *get_lock_stats(struct lock_class *class) { return &this_cpu_ptr(cpu_lock_stats)[class - lock_classes]; } static void lock_release_holdtime(struct held_lock *hlock) { struct lock_class_stats *stats; u64 holdtime; if (!lock_stat) return; holdtime = lockstat_clock() - hlock->holdtime_stamp; stats = get_lock_stats(hlock_class(hlock)); if (hlock->read) lock_time_inc(&stats->read_holdtime, holdtime); else lock_time_inc(&stats->write_holdtime, holdtime); } #else static inline void lock_release_holdtime(struct held_lock *hlock) { } #endif /* * We keep a global list of all lock classes. The list is only accessed with * the lockdep spinlock lock held. free_lock_classes is a list with free * elements. These elements are linked together by the lock_entry member in * struct lock_class. */ LIST_HEAD(all_lock_classes); static LIST_HEAD(free_lock_classes); /** * struct pending_free - information about data structures about to be freed * @zapped: Head of a list with struct lock_class elements. * @lock_chains_being_freed: Bitmap that indicates which lock_chains[] elements * are about to be freed. */ struct pending_free { struct list_head zapped; DECLARE_BITMAP(lock_chains_being_freed, MAX_LOCKDEP_CHAINS); }; /** * struct delayed_free - data structures used for delayed freeing * * A data structure for delayed freeing of data structures that may be * accessed by RCU readers at the time these were freed. * * @rcu_head: Used to schedule an RCU callback for freeing data structures. * @index: Index of @pf to which freed data structures are added. * @scheduled: Whether or not an RCU callback has been scheduled. * @pf: Array with information about data structures about to be freed. */ static struct delayed_free { struct rcu_head rcu_head; int index; int scheduled; struct pending_free pf[2]; } delayed_free; /* * The lockdep classes are in a hash-table as well, for fast lookup: */ #define CLASSHASH_BITS (MAX_LOCKDEP_KEYS_BITS - 1) #define CLASSHASH_SIZE (1UL << CLASSHASH_BITS) #define __classhashfn(key) hash_long((unsigned long)key, CLASSHASH_BITS) #define classhashentry(key) (classhash_table + __classhashfn((key))) static struct hlist_head classhash_table[CLASSHASH_SIZE]; /* * We put the lock dependency chains into a hash-table as well, to cache * their existence: */ #define CHAINHASH_BITS (MAX_LOCKDEP_CHAINS_BITS-1) #define CHAINHASH_SIZE (1UL << CHAINHASH_BITS) #define __chainhashfn(chain) hash_long(chain, CHAINHASH_BITS) #define chainhashentry(chain) (chainhash_table + __chainhashfn((chain))) static struct hlist_head chainhash_table[CHAINHASH_SIZE]; /* * The hash key of the lock dependency chains is a hash itself too: * it's a hash of all locks taken up to that lock, including that lock. * It's a 64-bit hash, because it's important for the keys to be * unique. */ static inline u64 iterate_chain_key(u64 key, u32 idx) { u32 k0 = key, k1 = key >> 32; __jhash_mix(idx, k0, k1); /* Macro that modifies arguments! */ return k0 | (u64)k1 << 32; } void lockdep_init_task(struct task_struct *task) { task->lockdep_depth = 0; /* no locks held yet */ task->curr_chain_key = INITIAL_CHAIN_KEY; task->lockdep_recursion = 0; } static __always_inline void lockdep_recursion_finish(void) { if (WARN_ON_ONCE((--current->lockdep_recursion) & LOCKDEP_RECURSION_MASK)) current->lockdep_recursion = 0; } void lockdep_set_selftest_task(struct task_struct *task) { lockdep_selftest_task_struct = task; } /* * Debugging switches: */ #define VERBOSE 0 #define VERY_VERBOSE 0 #if VERBOSE # define HARDIRQ_VERBOSE 1 # define SOFTIRQ_VERBOSE 1 #else # define HARDIRQ_VERBOSE 0 # define SOFTIRQ_VERBOSE 0 #endif #if VERBOSE || HARDIRQ_VERBOSE || SOFTIRQ_VERBOSE /* * Quick filtering for interesting events: */ static int class_filter(struct lock_class *class) { #if 0 /* Example */ if (class->name_version == 1 && !strcmp(class->name, "lockname")) return 1; if (class->name_version == 1 && !strcmp(class->name, "&struct->lockfield")) return 1; #endif /* Filter everything else. 1 would be to allow everything else */ return 0; } #endif static int verbose(struct lock_class *class) { #if VERBOSE return class_filter(class); #endif return 0; } static void print_lockdep_off(const char *bug_msg) { printk(KERN_DEBUG "%s\n", bug_msg); printk(KERN_DEBUG "turning off the locking correctness validator.\n"); #ifdef CONFIG_LOCK_STAT printk(KERN_DEBUG "Please attach the output of /proc/lock_stat to the bug report\n"); #endif } unsigned long nr_stack_trace_entries; #ifdef CONFIG_PROVE_LOCKING /** * struct lock_trace - single stack backtrace * @hash_entry: Entry in a stack_trace_hash[] list. * @hash: jhash() of @entries. * @nr_entries: Number of entries in @entries. * @entries: Actual stack backtrace. */ struct lock_trace { struct hlist_node hash_entry; u32 hash; u32 nr_entries; unsigned long entries[] __aligned(sizeof(unsigned long)); }; #define LOCK_TRACE_SIZE_IN_LONGS \ (sizeof(struct lock_trace) / sizeof(unsigned long)) /* * Stack-trace: sequence of lock_trace structures. Protected by the graph_lock. */ static unsigned long stack_trace[MAX_STACK_TRACE_ENTRIES]; static struct hlist_head stack_trace_hash[STACK_TRACE_HASH_SIZE]; static bool traces_identical(struct lock_trace *t1, struct lock_trace *t2) { return t1->hash == t2->hash && t1->nr_entries == t2->nr_entries && memcmp(t1->entries, t2->entries, t1->nr_entries * sizeof(t1->entries[0])) == 0; } static struct lock_trace *save_trace(void) { struct lock_trace *trace, *t2; struct hlist_head *hash_head; u32 hash; int max_entries; BUILD_BUG_ON_NOT_POWER_OF_2(STACK_TRACE_HASH_SIZE); BUILD_BUG_ON(LOCK_TRACE_SIZE_IN_LONGS >= MAX_STACK_TRACE_ENTRIES); trace = (struct lock_trace *)(stack_trace + nr_stack_trace_entries);