Commit a21ee605 authored by Peter Zijlstra's avatar Peter Zijlstra

lockdep: Change hardirq{s_enabled,_context} to per-cpu variables

Currently all IRQ-tracking state is in task_struct, this means that
task_struct needs to be defined before we use it.

Especially for lockdep_assert_irq*() this can lead to header-hell.

Move the hardirq state into per-cpu variables to avoid the task_struct
dependency.
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarIngo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20200623083721.512673481@infradead.org
parent a6342915
...@@ -14,6 +14,7 @@ ...@@ -14,6 +14,7 @@
#include <linux/typecheck.h> #include <linux/typecheck.h>
#include <asm/irqflags.h> #include <asm/irqflags.h>
#include <asm/percpu.h>
/* Currently lockdep_softirqs_on/off is used only by lockdep */ /* Currently lockdep_softirqs_on/off is used only by lockdep */
#ifdef CONFIG_PROVE_LOCKING #ifdef CONFIG_PROVE_LOCKING
...@@ -31,18 +32,22 @@ ...@@ -31,18 +32,22 @@
#endif #endif
#ifdef CONFIG_TRACE_IRQFLAGS #ifdef CONFIG_TRACE_IRQFLAGS
DECLARE_PER_CPU(int, hardirqs_enabled);
DECLARE_PER_CPU(int, hardirq_context);
extern void trace_hardirqs_on_prepare(void); extern void trace_hardirqs_on_prepare(void);
extern void trace_hardirqs_off_finish(void); extern void trace_hardirqs_off_finish(void);
extern void trace_hardirqs_on(void); extern void trace_hardirqs_on(void);
extern void trace_hardirqs_off(void); extern void trace_hardirqs_off(void);
# define lockdep_hardirq_context(p) ((p)->hardirq_context) # define lockdep_hardirq_context(p) (this_cpu_read(hardirq_context))
# define lockdep_softirq_context(p) ((p)->softirq_context) # define lockdep_softirq_context(p) ((p)->softirq_context)
# define lockdep_hardirqs_enabled(p) ((p)->hardirqs_enabled) # define lockdep_hardirqs_enabled(p) (this_cpu_read(hardirqs_enabled))
# define lockdep_softirqs_enabled(p) ((p)->softirqs_enabled) # define lockdep_softirqs_enabled(p) ((p)->softirqs_enabled)
# define lockdep_hardirq_enter() \ # define lockdep_hardirq_enter() \
do { \ do { \
if (!current->hardirq_context++) \ if (this_cpu_inc_return(hardirq_context) == 1) \
current->hardirq_threaded = 0; \ current->hardirq_threaded = 0; \
} while (0) } while (0)
# define lockdep_hardirq_threaded() \ # define lockdep_hardirq_threaded() \
do { \ do { \
...@@ -50,7 +55,7 @@ do { \ ...@@ -50,7 +55,7 @@ do { \
} while (0) } while (0)
# define lockdep_hardirq_exit() \ # define lockdep_hardirq_exit() \
do { \ do { \
current->hardirq_context--; \ this_cpu_dec(hardirq_context); \
} while (0) } while (0)
# define lockdep_softirq_enter() \ # define lockdep_softirq_enter() \
do { \ do { \
......
...@@ -11,6 +11,7 @@ ...@@ -11,6 +11,7 @@
#define __LINUX_LOCKDEP_H #define __LINUX_LOCKDEP_H
#include <linux/lockdep_types.h> #include <linux/lockdep_types.h>
#include <asm/percpu.h>
struct task_struct; struct task_struct;
...@@ -529,28 +530,29 @@ do { \ ...@@ -529,28 +530,29 @@ do { \
lock_release(&(lock)->dep_map, _THIS_IP_); \ lock_release(&(lock)->dep_map, _THIS_IP_); \
} while (0) } while (0)
#define lockdep_assert_irqs_enabled() do { \ DECLARE_PER_CPU(int, hardirqs_enabled);
WARN_ONCE(debug_locks && !current->lockdep_recursion && \ DECLARE_PER_CPU(int, hardirq_context);
!current->hardirqs_enabled, \
"IRQs not enabled as expected\n"); \
} while (0)
#define lockdep_assert_irqs_disabled() do { \ #define lockdep_assert_irqs_enabled() \
WARN_ONCE(debug_locks && !current->lockdep_recursion && \ do { \
current->hardirqs_enabled, \ WARN_ON_ONCE(debug_locks && !this_cpu_read(hardirqs_enabled)); \
"IRQs not disabled as expected\n"); \ } while (0)
} while (0)
#define lockdep_assert_in_irq() do { \ #define lockdep_assert_irqs_disabled() \
WARN_ONCE(debug_locks && !current->lockdep_recursion && \ do { \
!current->hardirq_context, \ WARN_ON_ONCE(debug_locks && this_cpu_read(hardirqs_enabled)); \
"Not in hardirq as expected\n"); \ } while (0)
} while (0)
#define lockdep_assert_in_irq() \
do { \
WARN_ON_ONCE(debug_locks && !this_cpu_read(hardirq_context)); \
} while (0)
#else #else
# define might_lock(lock) do { } while (0) # define might_lock(lock) do { } while (0)
# define might_lock_read(lock) do { } while (0) # define might_lock_read(lock) do { } while (0)
# define might_lock_nested(lock, subclass) do { } while (0) # define might_lock_nested(lock, subclass) do { } while (0)
# define lockdep_assert_irqs_enabled() do { } while (0) # define lockdep_assert_irqs_enabled() do { } while (0)
# define lockdep_assert_irqs_disabled() do { } while (0) # define lockdep_assert_irqs_disabled() do { } while (0)
# define lockdep_assert_in_irq() do { } while (0) # define lockdep_assert_in_irq() do { } while (0)
...@@ -560,7 +562,7 @@ do { \ ...@@ -560,7 +562,7 @@ do { \
# define lockdep_assert_RT_in_threaded_ctx() do { \ # define lockdep_assert_RT_in_threaded_ctx() do { \
WARN_ONCE(debug_locks && !current->lockdep_recursion && \ WARN_ONCE(debug_locks && !current->lockdep_recursion && \
current->hardirq_context && \ lockdep_hardirq_context(current) && \
!(current->hardirq_threaded || current->irq_config), \ !(current->hardirq_threaded || current->irq_config), \
"Not in threaded context on PREEMPT_RT as expected\n"); \ "Not in threaded context on PREEMPT_RT as expected\n"); \
} while (0) } while (0)
......
...@@ -990,8 +990,6 @@ struct task_struct { ...@@ -990,8 +990,6 @@ struct task_struct {
unsigned long hardirq_disable_ip; unsigned long hardirq_disable_ip;
unsigned int hardirq_enable_event; unsigned int hardirq_enable_event;
unsigned int hardirq_disable_event; unsigned int hardirq_disable_event;
int hardirqs_enabled;
int hardirq_context;
u64 hardirq_chain_key; u64 hardirq_chain_key;
unsigned long softirq_disable_ip; unsigned long softirq_disable_ip;
unsigned long softirq_enable_ip; unsigned long softirq_enable_ip;
......
...@@ -1954,8 +1954,8 @@ static __latent_entropy struct task_struct *copy_process( ...@@ -1954,8 +1954,8 @@ static __latent_entropy struct task_struct *copy_process(
rt_mutex_init_task(p); rt_mutex_init_task(p);
lockdep_assert_irqs_enabled();
#ifdef CONFIG_PROVE_LOCKING #ifdef CONFIG_PROVE_LOCKING
DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled);
DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled); DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled);
#endif #endif
retval = -EAGAIN; retval = -EAGAIN;
...@@ -2036,7 +2036,6 @@ static __latent_entropy struct task_struct *copy_process( ...@@ -2036,7 +2036,6 @@ static __latent_entropy struct task_struct *copy_process(
#endif #endif
#ifdef CONFIG_TRACE_IRQFLAGS #ifdef CONFIG_TRACE_IRQFLAGS
p->irq_events = 0; p->irq_events = 0;
p->hardirqs_enabled = 0;
p->hardirq_enable_ip = 0; p->hardirq_enable_ip = 0;
p->hardirq_enable_event = 0; p->hardirq_enable_event = 0;
p->hardirq_disable_ip = _THIS_IP_; p->hardirq_disable_ip = _THIS_IP_;
...@@ -2046,7 +2045,6 @@ static __latent_entropy struct task_struct *copy_process( ...@@ -2046,7 +2045,6 @@ static __latent_entropy struct task_struct *copy_process(
p->softirq_enable_event = 0; p->softirq_enable_event = 0;
p->softirq_disable_ip = 0; p->softirq_disable_ip = 0;
p->softirq_disable_event = 0; p->softirq_disable_event = 0;
p->hardirq_context = 0;
p->softirq_context = 0; p->softirq_context = 0;
#endif #endif
......
...@@ -2062,9 +2062,9 @@ print_bad_irq_dependency(struct task_struct *curr, ...@@ -2062,9 +2062,9 @@ print_bad_irq_dependency(struct task_struct *curr,
pr_warn("-----------------------------------------------------\n"); pr_warn("-----------------------------------------------------\n");
pr_warn("%s/%d [HC%u[%lu]:SC%u[%lu]:HE%u:SE%u] is trying to acquire:\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->comm, task_pid_nr(curr),
curr->hardirq_context, hardirq_count() >> HARDIRQ_SHIFT, lockdep_hardirq_context(curr), hardirq_count() >> HARDIRQ_SHIFT,
curr->softirq_context, softirq_count() >> SOFTIRQ_SHIFT, curr->softirq_context, softirq_count() >> SOFTIRQ_SHIFT,
curr->hardirqs_enabled, lockdep_hardirqs_enabled(curr),
curr->softirqs_enabled); curr->softirqs_enabled);
print_lock(next); print_lock(next);
...@@ -3658,7 +3658,7 @@ void lockdep_hardirqs_on_prepare(unsigned long ip) ...@@ -3658,7 +3658,7 @@ void lockdep_hardirqs_on_prepare(unsigned long ip)
if (unlikely(current->lockdep_recursion & LOCKDEP_RECURSION_MASK)) if (unlikely(current->lockdep_recursion & LOCKDEP_RECURSION_MASK))
return; return;
if (unlikely(current->hardirqs_enabled)) { if (unlikely(lockdep_hardirqs_enabled(current))) {
/* /*
* Neither irq nor preemption are disabled here * Neither irq nor preemption are disabled here
* so this is racy by nature but losing one hit * so this is racy by nature but losing one hit
...@@ -3686,7 +3686,7 @@ void lockdep_hardirqs_on_prepare(unsigned long ip) ...@@ -3686,7 +3686,7 @@ void lockdep_hardirqs_on_prepare(unsigned long ip)
* Can't allow enabling interrupts while in an interrupt handler, * Can't allow enabling interrupts while in an interrupt handler,
* that's general bad form and such. Recursion, limited stack etc.. * 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(current)))
return; return;
current->hardirq_chain_key = current->curr_chain_key; current->hardirq_chain_key = current->curr_chain_key;
...@@ -3724,7 +3724,7 @@ void noinstr lockdep_hardirqs_on(unsigned long ip) ...@@ -3724,7 +3724,7 @@ void noinstr lockdep_hardirqs_on(unsigned long ip)
if (unlikely(current->lockdep_recursion & LOCKDEP_RECURSION_MASK)) if (unlikely(current->lockdep_recursion & LOCKDEP_RECURSION_MASK))
return; return;
if (curr->hardirqs_enabled) { if (lockdep_hardirqs_enabled(curr)) {
/* /*
* Neither irq nor preemption are disabled here * Neither irq nor preemption are disabled here
* so this is racy by nature but losing one hit * so this is racy by nature but losing one hit
...@@ -3751,7 +3751,7 @@ void noinstr lockdep_hardirqs_on(unsigned long ip) ...@@ -3751,7 +3751,7 @@ void noinstr lockdep_hardirqs_on(unsigned long ip)
skip_checks: skip_checks:
/* we'll do an OFF -> ON transition: */ /* we'll do an OFF -> ON transition: */
curr->hardirqs_enabled = 1; this_cpu_write(hardirqs_enabled, 1);
curr->hardirq_enable_ip = ip; curr->hardirq_enable_ip = ip;
curr->hardirq_enable_event = ++curr->irq_events; curr->hardirq_enable_event = ++curr->irq_events;
debug_atomic_inc(hardirqs_on_events); debug_atomic_inc(hardirqs_on_events);
...@@ -3783,11 +3783,11 @@ void noinstr lockdep_hardirqs_off(unsigned long ip) ...@@ -3783,11 +3783,11 @@ void noinstr lockdep_hardirqs_off(unsigned long ip)
if (DEBUG_LOCKS_WARN_ON(!irqs_disabled())) if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
return; return;
if (curr->hardirqs_enabled) { if (lockdep_hardirqs_enabled(curr)) {
/* /*
* We have done an ON -> OFF transition: * We have done an ON -> OFF transition:
*/ */
curr->hardirqs_enabled = 0; this_cpu_write(hardirqs_enabled, 0);
curr->hardirq_disable_ip = ip; curr->hardirq_disable_ip = ip;
curr->hardirq_disable_event = ++curr->irq_events; curr->hardirq_disable_event = ++curr->irq_events;
debug_atomic_inc(hardirqs_off_events); debug_atomic_inc(hardirqs_off_events);
...@@ -3832,7 +3832,7 @@ void lockdep_softirqs_on(unsigned long ip) ...@@ -3832,7 +3832,7 @@ void lockdep_softirqs_on(unsigned long ip)
* usage bit for all held locks, if hardirqs are * usage bit for all held locks, if hardirqs are
* enabled too: * enabled too:
*/ */
if (curr->hardirqs_enabled) if (lockdep_hardirqs_enabled(curr))
mark_held_locks(curr, LOCK_ENABLED_SOFTIRQ); mark_held_locks(curr, LOCK_ENABLED_SOFTIRQ);
lockdep_recursion_finish(); lockdep_recursion_finish();
} }
...@@ -3881,7 +3881,7 @@ mark_usage(struct task_struct *curr, struct held_lock *hlock, int check) ...@@ -3881,7 +3881,7 @@ mark_usage(struct task_struct *curr, struct held_lock *hlock, int check)
*/ */
if (!hlock->trylock) { if (!hlock->trylock) {
if (hlock->read) { if (hlock->read) {
if (curr->hardirq_context) if (lockdep_hardirq_context(curr))
if (!mark_lock(curr, hlock, if (!mark_lock(curr, hlock,
LOCK_USED_IN_HARDIRQ_READ)) LOCK_USED_IN_HARDIRQ_READ))
return 0; return 0;
...@@ -3890,7 +3890,7 @@ mark_usage(struct task_struct *curr, struct held_lock *hlock, int check) ...@@ -3890,7 +3890,7 @@ mark_usage(struct task_struct *curr, struct held_lock *hlock, int check)
LOCK_USED_IN_SOFTIRQ_READ)) LOCK_USED_IN_SOFTIRQ_READ))
return 0; return 0;
} else { } else {
if (curr->hardirq_context) if (lockdep_hardirq_context(curr))
if (!mark_lock(curr, hlock, LOCK_USED_IN_HARDIRQ)) if (!mark_lock(curr, hlock, LOCK_USED_IN_HARDIRQ))
return 0; return 0;
if (curr->softirq_context) if (curr->softirq_context)
...@@ -3928,7 +3928,7 @@ mark_usage(struct task_struct *curr, struct held_lock *hlock, int check) ...@@ -3928,7 +3928,7 @@ mark_usage(struct task_struct *curr, struct held_lock *hlock, int check)
static inline unsigned int task_irq_context(struct task_struct *task) 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(task) +
LOCK_CHAIN_SOFTIRQ_CONTEXT * !!task->softirq_context; LOCK_CHAIN_SOFTIRQ_CONTEXT * !!task->softirq_context;
} }
...@@ -4021,7 +4021,7 @@ static inline short task_wait_context(struct task_struct *curr) ...@@ -4021,7 +4021,7 @@ static inline short task_wait_context(struct task_struct *curr)
* Set appropriate wait type for the context; for IRQs we have to take * Set appropriate wait type for the context; for IRQs we have to take
* into account force_irqthread as that is implied by PREEMPT_RT. * into account force_irqthread as that is implied by PREEMPT_RT.
*/ */
if (curr->hardirq_context) { if (lockdep_hardirq_context(curr)) {
/* /*
* Check if force_irqthreads will run us threaded. * Check if force_irqthreads will run us threaded.
*/ */
...@@ -4864,11 +4864,11 @@ static void check_flags(unsigned long flags) ...@@ -4864,11 +4864,11 @@ static void check_flags(unsigned long flags)
return; return;
if (irqs_disabled_flags(flags)) { if (irqs_disabled_flags(flags)) {
if (DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled)) { if (DEBUG_LOCKS_WARN_ON(lockdep_hardirqs_enabled(current))) {
printk("possible reason: unannotated irqs-off.\n"); printk("possible reason: unannotated irqs-off.\n");
} }
} else { } else {
if (DEBUG_LOCKS_WARN_ON(!current->hardirqs_enabled)) { if (DEBUG_LOCKS_WARN_ON(!lockdep_hardirqs_enabled(current))) {
printk("possible reason: unannotated irqs-on.\n"); printk("possible reason: unannotated irqs-on.\n");
} }
} }
......
...@@ -107,6 +107,12 @@ static bool ksoftirqd_running(unsigned long pending) ...@@ -107,6 +107,12 @@ static bool ksoftirqd_running(unsigned long pending)
* where hardirqs are disabled legitimately: * where hardirqs are disabled legitimately:
*/ */
#ifdef CONFIG_TRACE_IRQFLAGS #ifdef CONFIG_TRACE_IRQFLAGS
DEFINE_PER_CPU(int, hardirqs_enabled);
DEFINE_PER_CPU(int, hardirq_context);
EXPORT_PER_CPU_SYMBOL_GPL(hardirqs_enabled);
EXPORT_PER_CPU_SYMBOL_GPL(hardirq_context);
void __local_bh_disable_ip(unsigned long ip, unsigned int cnt) void __local_bh_disable_ip(unsigned long ip, unsigned int cnt)
{ {
unsigned long flags; unsigned long flags;
......
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