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Diffstat (limited to 'kernel/locking/lockdep.c')
-rw-r--r--kernel/locking/lockdep.c162
1 files changed, 103 insertions, 59 deletions
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 29a8de4c50b9..2fad21d345b0 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -395,7 +395,7 @@ void lockdep_init_task(struct task_struct *task)
static __always_inline void lockdep_recursion_finish(void)
{
- if (WARN_ON_ONCE(--current->lockdep_recursion))
+ if (WARN_ON_ONCE((--current->lockdep_recursion) & LOCKDEP_RECURSION_MASK))
current->lockdep_recursion = 0;
}
@@ -1723,7 +1723,7 @@ static int noop_count(struct lock_list *entry, void *data)
static unsigned long __lockdep_count_forward_deps(struct lock_list *this)
{
unsigned long count = 0;
- struct lock_list *uninitialized_var(target_entry);
+ struct lock_list *target_entry;
__bfs_forwards(this, (void *)&count, noop_count, &target_entry);
@@ -1749,7 +1749,7 @@ unsigned long lockdep_count_forward_deps(struct lock_class *class)
static unsigned long __lockdep_count_backward_deps(struct lock_list *this)
{
unsigned long count = 0;
- struct lock_list *uninitialized_var(target_entry);
+ struct lock_list *target_entry;
__bfs_backwards(this, (void *)&count, noop_count, &target_entry);
@@ -1804,7 +1804,7 @@ check_noncircular(struct held_lock *src, struct held_lock *target,
struct lock_trace **const trace)
{
int ret;
- struct lock_list *uninitialized_var(target_entry);
+ struct lock_list *target_entry;
struct lock_list src_entry = {
.class = hlock_class(src),
.parent = NULL,
@@ -1842,7 +1842,7 @@ static noinline int
check_redundant(struct held_lock *src, struct held_lock *target)
{
int ret;
- struct lock_list *uninitialized_var(target_entry);
+ struct lock_list *target_entry;
struct lock_list src_entry = {
.class = hlock_class(src),
.parent = NULL,
@@ -2062,9 +2062,9 @@ print_bad_irq_dependency(struct task_struct *curr,
pr_warn("-----------------------------------------------------\n");
pr_warn("%s/%d [HC%u[%lu]:SC%u[%lu]:HE%u:SE%u] is trying to acquire:\n",
curr->comm, task_pid_nr(curr),
- curr->hardirq_context, hardirq_count() >> HARDIRQ_SHIFT,
+ lockdep_hardirq_context(), hardirq_count() >> HARDIRQ_SHIFT,
curr->softirq_context, softirq_count() >> SOFTIRQ_SHIFT,
- curr->hardirqs_enabled,
+ lockdep_hardirqs_enabled(),
curr->softirqs_enabled);
print_lock(next);
@@ -2244,8 +2244,8 @@ static int check_irq_usage(struct task_struct *curr, struct held_lock *prev,
{
unsigned long usage_mask = 0, forward_mask, backward_mask;
enum lock_usage_bit forward_bit = 0, backward_bit = 0;
- struct lock_list *uninitialized_var(target_entry1);
- struct lock_list *uninitialized_var(target_entry);
+ struct lock_list *target_entry1;
+ struct lock_list *target_entry;
struct lock_list this, that;
int ret;
@@ -3331,9 +3331,9 @@ print_usage_bug(struct task_struct *curr, struct held_lock *this,
pr_warn("%s/%d [HC%u[%lu]:SC%u[%lu]:HE%u:SE%u] takes:\n",
curr->comm, task_pid_nr(curr),
- lockdep_hardirq_context(curr), hardirq_count() >> HARDIRQ_SHIFT,
+ lockdep_hardirq_context(), hardirq_count() >> HARDIRQ_SHIFT,
lockdep_softirq_context(curr), softirq_count() >> SOFTIRQ_SHIFT,
- lockdep_hardirqs_enabled(curr),
+ lockdep_hardirqs_enabled(),
lockdep_softirqs_enabled(curr));
print_lock(this);
@@ -3438,7 +3438,7 @@ check_usage_forwards(struct task_struct *curr, struct held_lock *this,
{
int ret;
struct lock_list root;
- struct lock_list *uninitialized_var(target_entry);
+ struct lock_list *target_entry;
root.parent = NULL;
root.class = hlock_class(this);
@@ -3465,7 +3465,7 @@ check_usage_backwards(struct task_struct *curr, struct held_lock *this,
{
int ret;
struct lock_list root;
- struct lock_list *uninitialized_var(target_entry);
+ struct lock_list *target_entry;
root.parent = NULL;
root.class = hlock_class(this);
@@ -3484,19 +3484,21 @@ check_usage_backwards(struct task_struct *curr, struct held_lock *this,
void print_irqtrace_events(struct task_struct *curr)
{
- printk("irq event stamp: %u\n", curr->irq_events);
+ const struct irqtrace_events *trace = &curr->irqtrace;
+
+ printk("irq event stamp: %u\n", trace->irq_events);
printk("hardirqs last enabled at (%u): [<%px>] %pS\n",
- curr->hardirq_enable_event, (void *)curr->hardirq_enable_ip,
- (void *)curr->hardirq_enable_ip);
+ trace->hardirq_enable_event, (void *)trace->hardirq_enable_ip,
+ (void *)trace->hardirq_enable_ip);
printk("hardirqs last disabled at (%u): [<%px>] %pS\n",
- curr->hardirq_disable_event, (void *)curr->hardirq_disable_ip,
- (void *)curr->hardirq_disable_ip);
+ trace->hardirq_disable_event, (void *)trace->hardirq_disable_ip,
+ (void *)trace->hardirq_disable_ip);
printk("softirqs last enabled at (%u): [<%px>] %pS\n",
- curr->softirq_enable_event, (void *)curr->softirq_enable_ip,
- (void *)curr->softirq_enable_ip);
+ trace->softirq_enable_event, (void *)trace->softirq_enable_ip,
+ (void *)trace->softirq_enable_ip);
printk("softirqs last disabled at (%u): [<%px>] %pS\n",
- curr->softirq_disable_event, (void *)curr->softirq_disable_ip,
- (void *)curr->softirq_disable_ip);
+ trace->softirq_disable_event, (void *)trace->softirq_disable_ip,
+ (void *)trace->softirq_disable_ip);
}
static int HARDIRQ_verbose(struct lock_class *class)
@@ -3646,10 +3648,19 @@ static void __trace_hardirqs_on_caller(void)
*/
void lockdep_hardirqs_on_prepare(unsigned long ip)
{
- if (unlikely(!debug_locks || current->lockdep_recursion))
+ if (unlikely(!debug_locks))
+ return;
+
+ /*
+ * NMIs do not (and cannot) track lock dependencies, nothing to do.
+ */
+ if (unlikely(in_nmi()))
+ return;
+
+ if (unlikely(current->lockdep_recursion & LOCKDEP_RECURSION_MASK))
return;
- if (unlikely(current->hardirqs_enabled)) {
+ if (unlikely(lockdep_hardirqs_enabled())) {
/*
* Neither irq nor preemption are disabled here
* so this is racy by nature but losing one hit
@@ -3677,7 +3688,7 @@ void lockdep_hardirqs_on_prepare(unsigned long ip)
* Can't allow enabling interrupts while in an interrupt handler,
* that's general bad form and such. Recursion, limited stack etc..
*/
- if (DEBUG_LOCKS_WARN_ON(current->hardirq_context))
+ if (DEBUG_LOCKS_WARN_ON(lockdep_hardirq_context()))
return;
current->hardirq_chain_key = current->curr_chain_key;
@@ -3690,12 +3701,35 @@ EXPORT_SYMBOL_GPL(lockdep_hardirqs_on_prepare);
void noinstr lockdep_hardirqs_on(unsigned long ip)
{
- struct task_struct *curr = current;
+ struct irqtrace_events *trace = &current->irqtrace;
+
+ if (unlikely(!debug_locks))
+ return;
+
+ /*
+ * NMIs can happen in the middle of local_irq_{en,dis}able() where the
+ * tracking state and hardware state are out of sync.
+ *
+ * NMIs must save lockdep_hardirqs_enabled() to restore IRQ state from,
+ * and not rely on hardware state like normal interrupts.
+ */
+ if (unlikely(in_nmi())) {
+ if (!IS_ENABLED(CONFIG_TRACE_IRQFLAGS_NMI))
+ return;
+
+ /*
+ * Skip:
+ * - recursion check, because NMI can hit lockdep;
+ * - hardware state check, because above;
+ * - chain_key check, see lockdep_hardirqs_on_prepare().
+ */
+ goto skip_checks;
+ }
- if (unlikely(!debug_locks || curr->lockdep_recursion))
+ if (unlikely(current->lockdep_recursion & LOCKDEP_RECURSION_MASK))
return;
- if (curr->hardirqs_enabled) {
+ if (lockdep_hardirqs_enabled()) {
/*
* Neither irq nor preemption are disabled here
* so this is racy by nature but losing one hit
@@ -3720,10 +3754,11 @@ void noinstr lockdep_hardirqs_on(unsigned long ip)
DEBUG_LOCKS_WARN_ON(current->hardirq_chain_key !=
current->curr_chain_key);
+skip_checks:
/* we'll do an OFF -> ON transition: */
- curr->hardirqs_enabled = 1;
- curr->hardirq_enable_ip = ip;
- curr->hardirq_enable_event = ++curr->irq_events;
+ this_cpu_write(hardirqs_enabled, 1);
+ trace->hardirq_enable_ip = ip;
+ trace->hardirq_enable_event = ++trace->irq_events;
debug_atomic_inc(hardirqs_on_events);
}
EXPORT_SYMBOL_GPL(lockdep_hardirqs_on);
@@ -3733,9 +3768,18 @@ EXPORT_SYMBOL_GPL(lockdep_hardirqs_on);
*/
void noinstr lockdep_hardirqs_off(unsigned long ip)
{
- struct task_struct *curr = current;
+ if (unlikely(!debug_locks))
+ return;
- if (unlikely(!debug_locks || curr->lockdep_recursion))
+ /*
+ * Matching lockdep_hardirqs_on(), allow NMIs in the middle of lockdep;
+ * they will restore the software state. This ensures the software
+ * state is consistent inside NMIs as well.
+ */
+ if (in_nmi()) {
+ if (!IS_ENABLED(CONFIG_TRACE_IRQFLAGS_NMI))
+ return;
+ } else if (current->lockdep_recursion & LOCKDEP_RECURSION_MASK)
return;
/*
@@ -3745,13 +3789,15 @@ void noinstr lockdep_hardirqs_off(unsigned long ip)
if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
return;
- if (curr->hardirqs_enabled) {
+ if (lockdep_hardirqs_enabled()) {
+ struct irqtrace_events *trace = &current->irqtrace;
+
/*
* We have done an ON -> OFF transition:
*/
- curr->hardirqs_enabled = 0;
- curr->hardirq_disable_ip = ip;
- curr->hardirq_disable_event = ++curr->irq_events;
+ this_cpu_write(hardirqs_enabled, 0);
+ trace->hardirq_disable_ip = ip;
+ trace->hardirq_disable_event = ++trace->irq_events;
debug_atomic_inc(hardirqs_off_events);
} else {
debug_atomic_inc(redundant_hardirqs_off);
@@ -3764,7 +3810,7 @@ EXPORT_SYMBOL_GPL(lockdep_hardirqs_off);
*/
void lockdep_softirqs_on(unsigned long ip)
{
- struct task_struct *curr = current;
+ struct irqtrace_events *trace = &current->irqtrace;
if (unlikely(!debug_locks || current->lockdep_recursion))
return;
@@ -3776,7 +3822,7 @@ void lockdep_softirqs_on(unsigned long ip)
if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
return;
- if (curr->softirqs_enabled) {
+ if (current->softirqs_enabled) {
debug_atomic_inc(redundant_softirqs_on);
return;
}
@@ -3785,17 +3831,17 @@ void lockdep_softirqs_on(unsigned long ip)
/*
* We'll do an OFF -> ON transition:
*/
- curr->softirqs_enabled = 1;
- curr->softirq_enable_ip = ip;
- curr->softirq_enable_event = ++curr->irq_events;
+ current->softirqs_enabled = 1;
+ trace->softirq_enable_ip = ip;
+ trace->softirq_enable_event = ++trace->irq_events;
debug_atomic_inc(softirqs_on_events);
/*
* We are going to turn softirqs on, so set the
* usage bit for all held locks, if hardirqs are
* enabled too:
*/
- if (curr->hardirqs_enabled)
- mark_held_locks(curr, LOCK_ENABLED_SOFTIRQ);
+ if (lockdep_hardirqs_enabled())
+ mark_held_locks(current, LOCK_ENABLED_SOFTIRQ);
lockdep_recursion_finish();
}
@@ -3804,8 +3850,6 @@ void lockdep_softirqs_on(unsigned long ip)
*/
void lockdep_softirqs_off(unsigned long ip)
{
- struct task_struct *curr = current;
-
if (unlikely(!debug_locks || current->lockdep_recursion))
return;
@@ -3815,13 +3859,15 @@ void lockdep_softirqs_off(unsigned long ip)
if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
return;
- if (curr->softirqs_enabled) {
+ if (current->softirqs_enabled) {
+ struct irqtrace_events *trace = &current->irqtrace;
+
/*
* We have done an ON -> OFF transition:
*/
- curr->softirqs_enabled = 0;
- curr->softirq_disable_ip = ip;
- curr->softirq_disable_event = ++curr->irq_events;
+ current->softirqs_enabled = 0;
+ trace->softirq_disable_ip = ip;
+ trace->softirq_disable_event = ++trace->irq_events;
debug_atomic_inc(softirqs_off_events);
/*
* Whoops, we wanted softirqs off, so why aren't they?
@@ -3843,7 +3889,7 @@ mark_usage(struct task_struct *curr, struct held_lock *hlock, int check)
*/
if (!hlock->trylock) {
if (hlock->read) {
- if (curr->hardirq_context)
+ if (lockdep_hardirq_context())
if (!mark_lock(curr, hlock,
LOCK_USED_IN_HARDIRQ_READ))
return 0;
@@ -3852,7 +3898,7 @@ mark_usage(struct task_struct *curr, struct held_lock *hlock, int check)
LOCK_USED_IN_SOFTIRQ_READ))
return 0;
} else {
- if (curr->hardirq_context)
+ if (lockdep_hardirq_context())
if (!mark_lock(curr, hlock, LOCK_USED_IN_HARDIRQ))
return 0;
if (curr->softirq_context)
@@ -3890,7 +3936,7 @@ lock_used:
static inline unsigned int task_irq_context(struct task_struct *task)
{
- return LOCK_CHAIN_HARDIRQ_CONTEXT * !!task->hardirq_context +
+ return LOCK_CHAIN_HARDIRQ_CONTEXT * !!lockdep_hardirq_context() +
LOCK_CHAIN_SOFTIRQ_CONTEXT * !!task->softirq_context;
}
@@ -3983,7 +4029,7 @@ static inline short task_wait_context(struct task_struct *curr)
* Set appropriate wait type for the context; for IRQs we have to take
* into account force_irqthread as that is implied by PREEMPT_RT.
*/
- if (curr->hardirq_context) {
+ if (lockdep_hardirq_context()) {
/*
* Check if force_irqthreads will run us threaded.
*/
@@ -4826,11 +4872,11 @@ static void check_flags(unsigned long flags)
return;
if (irqs_disabled_flags(flags)) {
- if (DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled)) {
+ if (DEBUG_LOCKS_WARN_ON(lockdep_hardirqs_enabled())) {
printk("possible reason: unannotated irqs-off.\n");
}
} else {
- if (DEBUG_LOCKS_WARN_ON(!current->hardirqs_enabled)) {
+ if (DEBUG_LOCKS_WARN_ON(!lockdep_hardirqs_enabled())) {
printk("possible reason: unannotated irqs-on.\n");
}
}
@@ -5851,9 +5897,7 @@ void lockdep_rcu_suspicious(const char *file, const int line, const char *s)
pr_warn("\n%srcu_scheduler_active = %d, debug_locks = %d\n",
!rcu_lockdep_current_cpu_online()
? "RCU used illegally from offline CPU!\n"
- : !rcu_is_watching()
- ? "RCU used illegally from idle CPU!\n"
- : "",
+ : "",
rcu_scheduler_active, debug_locks);
/*
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-12-04 03:14:27 +0000