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Merge tag 'locking-core-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Browse Source 
Pull locking updates from Ingo Molnar:

 - rtmutex cleanup & spring cleaning pass that removes ~400 lines of
   code

 - Futex simplifications & cleanups

 - Add debugging to the CSD code, to help track down a tenacious race
   (or hw problem)

 - Add lockdep_assert_not_held(), to allow code to require a lock to not
   be held, and propagate this into the ath10k driver

 - Misc LKMM documentation updates

 - Misc KCSAN updates: cleanups & documentation updates

 - Misc fixes and cleanups

 - Fix locktorture bugs with ww_mutexes

* tag 'locking-core-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (44 commits)
  kcsan: Fix printk format string
  static_call: Relax static_call_update() function argument type
  static_call: Fix unused variable warn w/o MODULE
  locking/rtmutex: Clean up signal handling in __rt_mutex_slowlock()
  locking/rtmutex: Restrict the trylock WARN_ON() to debug
  locking/rtmutex: Fix misleading comment in rt_mutex_postunlock()
  locking/rtmutex: Consolidate the fast/slowpath invocation
  locking/rtmutex: Make text section and inlining consistent
  locking/rtmutex: Move debug functions as inlines into common header
  locking/rtmutex: Decrapify __rt_mutex_init()
  locking/rtmutex: Remove pointless CONFIG_RT_MUTEXES=n stubs
  locking/rtmutex: Inline chainwalk depth check
  locking/rtmutex: Move rt_mutex_debug_task_free() to rtmutex.c
  locking/rtmutex: Remove empty and unused debug stubs
  locking/rtmutex: Consolidate rt_mutex_init()
  locking/rtmutex: Remove output from deadlock detector
  locking/rtmutex: Remove rtmutex deadlock tester leftovers
  locking/rtmutex: Remove rt_mutex_timed_lock()
  MAINTAINERS: Add myself as futex reviewer
  locking/mutex: Remove repeated declaration
  ...
This commit is contained in:
Linus Torvalds
2021-04-28 12:37:53 -07:00
parent 9a45da9270 f4abe9967c
commit 0ff0edb550
44 changed files with 1248 additions and 829 deletions
Download Patch File Download Diff File Expand all files Collapse all files

29
kernel/futex.c
View File

@@ -981,6 +981,7 @@ static inline void exit_pi_state_list(struct task_struct *curr) { }
* p->pi_lock:
*
* p->pi_state_list -> pi_state->list, relation
* pi_mutex->owner -> pi_state->owner, relation
*
* pi_state->refcount:
*
@@ -1494,13 +1495,14 @@ static void mark_wake_futex(struct wake_q_head *wake_q, struct futex_q *q)
static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_pi_state *pi_state)
{
u32 curval, newval;
struct rt_mutex_waiter *top_waiter;
struct task_struct *new_owner;
bool postunlock = false;
DEFINE_WAKE_Q(wake_q);
int ret = 0;
new_owner = rt_mutex_next_owner(&pi_state->pi_mutex);
if (WARN_ON_ONCE(!new_owner)) {
top_waiter = rt_mutex_top_waiter(&pi_state->pi_mutex);
if (WARN_ON_ONCE(!top_waiter)) {
/*
* As per the comment in futex_unlock_pi() this should not happen.
*
@@ -1513,6 +1515,8 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_pi_state *pi_
goto out_unlock;
}
new_owner = top_waiter->task;
/*
* We pass it to the next owner. The WAITERS bit is always kept
* enabled while there is PI state around. We cleanup the owner
@@ -2315,19 +2319,15 @@ retry:
/*
* PI futexes can not be requeued and must remove themself from the
* hash bucket. The hash bucket lock (i.e. lock_ptr) is held on entry
* and dropped here.
* hash bucket. The hash bucket lock (i.e. lock_ptr) is held.
*/
static void unqueue_me_pi(struct futex_q *q)
__releases(q->lock_ptr)
{
__unqueue_futex(q);
BUG_ON(!q->pi_state);
put_pi_state(q->pi_state);
q->pi_state = NULL;
spin_unlock(q->lock_ptr);
}
static int __fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q,
@@ -2909,8 +2909,8 @@ no_block:
if (res)
ret = (res < 0) ? res : 0;
/* Unqueue and drop the lock */
unqueue_me_pi(&q);
spin_unlock(q.lock_ptr);
goto out;
out_unlock_put_key:
@@ -3237,15 +3237,14 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
* reference count.
*/
/* Check if the requeue code acquired the second futex for us. */
/*
* Check if the requeue code acquired the second futex for us and do
* any pertinent fixup.
*/
if (!q.rt_waiter) {
/*
* Got the lock. We might not be the anticipated owner if we
* did a lock-steal - fix up the PI-state in that case.
*/
if (q.pi_state && (q.pi_state->owner != current)) {
spin_lock(q.lock_ptr);
ret = fixup_pi_state_owner(uaddr2, &q, current);
ret = fixup_owner(uaddr2, &q, true);
/*
* Drop the reference to the pi state which
* the requeue_pi() code acquired for us.
@@ -3287,8 +3286,8 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
if (res)
ret = (res < 0) ? res : 0;
/* Unqueue and drop the lock. */
unqueue_me_pi(&q);
spin_unlock(q.lock_ptr);
}
if (ret == -EINTR) {

4
kernel/kcsan/Makefile
View File

@@ -13,5 +13,5 @@ CFLAGS_core.o := $(call cc-option,-fno-conserve-stack) \
obj-y := core.o debugfs.o report.o
obj-$(CONFIG_KCSAN_SELFTEST) += selftest.o
CFLAGS_kcsan-test.o := $(CFLAGS_KCSAN) -g -fno-omit-frame-pointer
obj-$(CONFIG_KCSAN_TEST) += kcsan-test.o
CFLAGS_kcsan_test.o := $(CFLAGS_KCSAN) -g -fno-omit-frame-pointer
obj-$(CONFIG_KCSAN_KUNIT_TEST) += kcsan_test.o

5
kernel/kcsan/atomic.h
View File

@@ -1,4 +1,9 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Rules for implicitly atomic memory accesses.
*
* Copyright (C) 2019, Google LLC.
*/
#ifndef _KERNEL_KCSAN_ATOMIC_H
#define _KERNEL_KCSAN_ATOMIC_H

7
kernel/kcsan/core.c
View File

@@ -1,4 +1,9 @@
// SPDX-License-Identifier: GPL-2.0
/*
* KCSAN core runtime.
*
* Copyright (C) 2019, Google LLC.
*/
#define pr_fmt(fmt) "kcsan: " fmt
@@ -639,8 +644,6 @@ void __init kcsan_init(void)
BUG_ON(!in_task());
kcsan_debugfs_init();
for_each_possible_cpu(cpu)
per_cpu(kcsan_rand_state, cpu) = (u32)get_cycles();

9
kernel/kcsan/debugfs.c
View File

@@ -1,4 +1,9 @@
// SPDX-License-Identifier: GPL-2.0
/*
* KCSAN debugfs interface.
*
* Copyright (C) 2019, Google LLC.
*/
#define pr_fmt(fmt) "kcsan: " fmt
@@ -261,7 +266,9 @@ static const struct file_operations debugfs_ops =
.release = single_release
};
void __init kcsan_debugfs_init(void)
static void __init kcsan_debugfs_init(void)
{
debugfs_create_file("kcsan", 0644, NULL, NULL, &debugfs_ops);
}
late_initcall(kcsan_debugfs_init);

5
kernel/kcsan/encoding.h
View File

@@ -1,4 +1,9 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* KCSAN watchpoint encoding.
*
* Copyright (C) 2019, Google LLC.
*/
#ifndef _KERNEL_KCSAN_ENCODING_H
#define _KERNEL_KCSAN_ENCODING_H

8
kernel/kcsan/kcsan.h
View File

@@ -1,8 +1,9 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* The Kernel Concurrency Sanitizer (KCSAN) infrastructure. For more info please
* see Documentation/dev-tools/kcsan.rst.
*
* Copyright (C) 2019, Google LLC.
*/
#ifndef _KERNEL_KCSAN_KCSAN_H
@@ -30,11 +31,6 @@ extern bool kcsan_enabled;
void kcsan_save_irqtrace(struct task_struct *task);
void kcsan_restore_irqtrace(struct task_struct *task);
/*
* Initialize debugfs file.
*/
void kcsan_debugfs_init(void);
/*
* Statistics counters displayed via debugfs; should only be modified in
* slow-paths.

120
kernel/kcsan/kcsan-test.c → kernel/kcsan/kcsan_test.c
View File

@@ -13,6 +13,8 @@
* Author: Marco Elver <elver@google.com>
*/
#define pr_fmt(fmt) "kcsan_test: " fmt
#include <kunit/test.h>
#include <linux/jiffies.h>
#include <linux/kcsan-checks.h>
@@ -951,22 +953,53 @@ static void test_atomic_builtins(struct kunit *test)
}
/*
* Each test case is run with different numbers of threads. Until KUnit supports
* passing arguments for each test case, we encode #threads in the test case
* name (read by get_num_threads()). [The '-' was chosen as a stylistic
* preference to separate test name and #threads.]
* Generate thread counts for all test cases. Values generated are in interval
* [2, 5] followed by exponentially increasing thread counts from 8 to 32.
*
* The thread counts are chosen to cover potentially interesting boundaries and
* corner cases (range 2-5), and then stress the system with larger counts.
* corner cases (2 to 5), and then stress the system with larger counts.
*/
#define KCSAN_KUNIT_CASE(test_name) \
{ .run_case = test_name, .name = #test_name "-02" }, \
{ .run_case = test_name, .name = #test_name "-03" }, \
{ .run_case = test_name, .name = #test_name "-04" }, \
{ .run_case = test_name, .name = #test_name "-05" }, \
{ .run_case = test_name, .name = #test_name "-08" }, \
{ .run_case = test_name, .name = #test_name "-16" }
static const void *nthreads_gen_params(const void *prev, char *desc)
{
long nthreads = (long)prev;
if (nthreads < 0 || nthreads >= 32)
nthreads = 0; /* stop */
else if (!nthreads)
nthreads = 2; /* initial value */
else if (nthreads < 5)
nthreads++;
else if (nthreads == 5)
nthreads = 8;
else
nthreads *= 2;
if (!IS_ENABLED(CONFIG_PREEMPT) || !IS_ENABLED(CONFIG_KCSAN_INTERRUPT_WATCHER)) {
/*
* Without any preemption, keep 2 CPUs free for other tasks, one
* of which is the main test case function checking for
* completion or failure.
*/
const long min_unused_cpus = IS_ENABLED(CONFIG_PREEMPT_NONE) ? 2 : 0;
const long min_required_cpus = 2 + min_unused_cpus;
if (num_online_cpus() < min_required_cpus) {
pr_err_once("Too few online CPUs (%u < %ld) for test\n",
num_online_cpus(), min_required_cpus);
nthreads = 0;
} else if (nthreads >= num_online_cpus() - min_unused_cpus) {
/* Use negative value to indicate last param. */
nthreads = -(num_online_cpus() - min_unused_cpus);
pr_warn_once("Limiting number of threads to %ld (only %d online CPUs)\n",
-nthreads, num_online_cpus());
}
}
snprintf(desc, KUNIT_PARAM_DESC_SIZE, "threads=%ld", abs(nthreads));
return (void *)nthreads;
}
#define KCSAN_KUNIT_CASE(test_name) KUNIT_CASE_PARAM(test_name, nthreads_gen_params)
static struct kunit_case kcsan_test_cases[] = {
KCSAN_KUNIT_CASE(test_basic),
KCSAN_KUNIT_CASE(test_concurrent_races),
@@ -996,24 +1029,6 @@ static struct kunit_case kcsan_test_cases[] = {
/* ===== End test cases ===== */
/* Get number of threads encoded in test name. */
static bool __no_kcsan
get_num_threads(const char *test, int *nthreads)
{
int len = strlen(test);
if (WARN_ON(len < 3))
return false;
*nthreads = test[len - 1] - '0';
*nthreads += (test[len - 2] - '0') * 10;
if (WARN_ON(*nthreads < 0))
return false;
return true;
}
/* Concurrent accesses from interrupts. */
__no_kcsan
static void access_thread_timer(struct timer_list *timer)
@@ -1076,9 +1091,6 @@ static int test_init(struct kunit *test)
if (!torture_init_begin((char *)test->name, 1))
return -EBUSY;
if (!get_num_threads(test->name, &nthreads))
goto err;
if (WARN_ON(threads))
goto err;
@@ -1087,38 +1099,18 @@ static int test_init(struct kunit *test)
goto err;
}
if (!IS_ENABLED(CONFIG_PREEMPT) || !IS_ENABLED(CONFIG_KCSAN_INTERRUPT_WATCHER)) {
/*
* Without any preemption, keep 2 CPUs free for other tasks, one
* of which is the main test case function checking for
* completion or failure.
*/
const int min_unused_cpus = IS_ENABLED(CONFIG_PREEMPT_NONE) ? 2 : 0;
const int min_required_cpus = 2 + min_unused_cpus;
nthreads = abs((long)test->param_value);
if (WARN_ON(!nthreads))
goto err;
if (num_online_cpus() < min_required_cpus) {
pr_err("%s: too few online CPUs (%u < %d) for test",
test->name, num_online_cpus(), min_required_cpus);
threads = kcalloc(nthreads + 1, sizeof(struct task_struct *), GFP_KERNEL);
if (WARN_ON(!threads))
goto err;
threads[nthreads] = NULL;
for (i = 0; i < nthreads; ++i) {
if (torture_create_kthread(access_thread, NULL, threads[i]))
goto err;
} else if (nthreads > num_online_cpus() - min_unused_cpus) {
nthreads = num_online_cpus() - min_unused_cpus;
pr_warn("%s: limiting number of threads to %d\n",
test->name, nthreads);
}
}
if (nthreads) {
threads = kcalloc(nthreads + 1, sizeof(struct task_struct *),
GFP_KERNEL);
if (WARN_ON(!threads))
goto err;
threads[nthreads] = NULL;
for (i = 0; i < nthreads; ++i) {
if (torture_create_kthread(access_thread, NULL,
threads[i]))
goto err;
}
}
torture_init_end();
@@ -1156,7 +1148,7 @@ static void test_exit(struct kunit *test)
}
static struct kunit_suite kcsan_test_suite = {
.name = "kcsan-test",
.name = "kcsan",
.test_cases = kcsan_test_cases,
.init = test_init,
.exit = test_exit,

5
kernel/kcsan/report.c
View File

@@ -1,4 +1,9 @@
// SPDX-License-Identifier: GPL-2.0
/*
* KCSAN reporting.
*
* Copyright (C) 2019, Google LLC.
*/
#include <linux/debug_locks.h>
#include <linux/delay.h>

5
kernel/kcsan/selftest.c
View File

@@ -1,4 +1,9 @@
// SPDX-License-Identifier: GPL-2.0
/*
* KCSAN short boot-time selftests.
*
* Copyright (C) 2019, Google LLC.
*/
#define pr_fmt(fmt) "kcsan: " fmt

2
kernel/locking/Makefile
View File

@@ -12,7 +12,6 @@ ifdef CONFIG_FUNCTION_TRACER
CFLAGS_REMOVE_lockdep.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_lockdep_proc.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_mutex-debug.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_rtmutex-debug.o = $(CC_FLAGS_FTRACE)
endif
obj-$(CONFIG_DEBUG_IRQFLAGS) += irqflag-debug.o
@@ -26,7 +25,6 @@ obj-$(CONFIG_LOCK_SPIN_ON_OWNER) += osq_lock.o
obj-$(CONFIG_PROVE_LOCKING) += spinlock.o
obj-$(CONFIG_QUEUED_SPINLOCKS) += qspinlock.o
obj-$(CONFIG_RT_MUTEXES) += rtmutex.o
obj-$(CONFIG_DEBUG_RT_MUTEXES) += rtmutex-debug.o
obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o
obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock_debug.o
obj-$(CONFIG_QUEUED_RWLOCKS) += qrwlock.o

19
kernel/locking/lockdep.c
View File

@@ -54,6 +54,7 @@
#include <linux/nmi.h>
#include <linux/rcupdate.h>
#include <linux/kprobes.h>
#include <linux/lockdep.h>
#include <asm/sections.h>
@@ -1747,7 +1748,7 @@ static enum bfs_result __bfs(struct lock_list *source_entry,
/*
* Step 4: if not match, expand the path by adding the
* forward or backwards dependencis in the search
* forward or backwards dependencies in the search
*
*/
first = true;
@@ -1916,7 +1917,7 @@ print_circular_bug_header(struct lock_list *entry, unsigned int depth,
* -> B is -(ER)-> or -(EN)->, then we don't need to add A -> B into the
* dependency graph, as any strong path ..-> A -> B ->.. we can get with
* having dependency A -> B, we could already get a equivalent path ..-> A ->
* .. -> B -> .. with A -> .. -> B. Therefore A -> B is reduntant.
* .. -> B -> .. with A -> .. -> B. Therefore A -> B is redundant.
*
* We need to make sure both the start and the end of A -> .. -> B is not
* weaker than A -> B. For the start part, please see the comment in
@@ -5253,13 +5254,13 @@ int __lock_is_held(const struct lockdep_map *lock, int read)
if (match_held_lock(hlock, lock)) {
if (read == -1 || hlock->read == read)
return 1;
return LOCK_STATE_HELD;
return 0;
return LOCK_STATE_NOT_HELD;
}
}
return 0;
return LOCK_STATE_NOT_HELD;
}
static struct pin_cookie __lock_pin_lock(struct lockdep_map *lock)
@@ -5538,10 +5539,14 @@ EXPORT_SYMBOL_GPL(lock_release);
noinstr int lock_is_held_type(const struct lockdep_map *lock, int read)
{
unsigned long flags;
int ret = 0;
int ret = LOCK_STATE_NOT_HELD;
/*
* Avoid false negative lockdep_assert_held() and
* lockdep_assert_not_held().
*/
if (unlikely(!lockdep_enabled()))
return 1; /* avoid false negative lockdep_assert_held() */
return LOCK_STATE_UNKNOWN;
raw_local_irq_save(flags);
check_flags(flags);

2
kernel/locking/lockdep_proc.c
View File

@@ -348,7 +348,7 @@ static int lockdep_stats_show(struct seq_file *m, void *v)
debug_locks);
/*
* Zappped classes and lockdep data buffers reuse statistics.
* Zapped classes and lockdep data buffers reuse statistics.
*/
seq_puts(m, "\n");
seq_printf(m, " zapped classes: %11lu\n",

146
kernel/locking/locktorture.c
View File

@@ -76,13 +76,13 @@ static void lock_torture_cleanup(void);
struct lock_torture_ops {
void (*init)(void);
void (*exit)(void);
int (*writelock)(void);
int (*writelock)(int tid);
void (*write_delay)(struct torture_random_state *trsp);
void (*task_boost)(struct torture_random_state *trsp);
void (*writeunlock)(void);
int (*readlock)(void);
void (*writeunlock)(int tid);
int (*readlock)(int tid);
void (*read_delay)(struct torture_random_state *trsp);
void (*readunlock)(void);
void (*readunlock)(int tid);
unsigned long flags; /* for irq spinlocks */
const char *name;
@@ -105,7 +105,7 @@ static struct lock_torture_cxt cxt = { 0, 0, false, false,
* Definitions for lock torture testing.
*/
static int torture_lock_busted_write_lock(void)
static int torture_lock_busted_write_lock(int tid __maybe_unused)
{
return 0; /* BUGGY, do not use in real life!!! */
}
@@ -122,7 +122,7 @@ static void torture_lock_busted_write_delay(struct torture_random_state *trsp)
torture_preempt_schedule(); /* Allow test to be preempted. */
}
static void torture_lock_busted_write_unlock(void)
static void torture_lock_busted_write_unlock(int tid __maybe_unused)
{
/* BUGGY, do not use in real life!!! */
}
@@ -145,7 +145,8 @@ static struct lock_torture_ops lock_busted_ops = {
static DEFINE_SPINLOCK(torture_spinlock);
static int torture_spin_lock_write_lock(void) __acquires(torture_spinlock)
static int torture_spin_lock_write_lock(int tid __maybe_unused)
__acquires(torture_spinlock)
{
spin_lock(&torture_spinlock);
return 0;
@@ -169,7 +170,8 @@ static void torture_spin_lock_write_delay(struct torture_random_state *trsp)
torture_preempt_schedule(); /* Allow test to be preempted. */
}
static void torture_spin_lock_write_unlock(void) __releases(torture_spinlock)
static void torture_spin_lock_write_unlock(int tid __maybe_unused)
__releases(torture_spinlock)
{
spin_unlock(&torture_spinlock);
}
@@ -185,7 +187,7 @@ static struct lock_torture_ops spin_lock_ops = {
.name = "spin_lock"
};
static int torture_spin_lock_write_lock_irq(void)
static int torture_spin_lock_write_lock_irq(int tid __maybe_unused)
__acquires(torture_spinlock)
{
unsigned long flags;
@@ -195,7 +197,7 @@ __acquires(torture_spinlock)
return 0;
}
static void torture_lock_spin_write_unlock_irq(void)
static void torture_lock_spin_write_unlock_irq(int tid __maybe_unused)
__releases(torture_spinlock)
{
spin_unlock_irqrestore(&torture_spinlock, cxt.cur_ops->flags);
@@ -214,7 +216,8 @@ static struct lock_torture_ops spin_lock_irq_ops = {
static DEFINE_RWLOCK(torture_rwlock);
static int torture_rwlock_write_lock(void) __acquires(torture_rwlock)
static int torture_rwlock_write_lock(int tid __maybe_unused)
__acquires(torture_rwlock)
{
write_lock(&torture_rwlock);
return 0;
@@ -235,12 +238,14 @@ static void torture_rwlock_write_delay(struct torture_random_state *trsp)
udelay(shortdelay_us);
}
static void torture_rwlock_write_unlock(void) __releases(torture_rwlock)
static void torture_rwlock_write_unlock(int tid __maybe_unused)
__releases(torture_rwlock)
{
write_unlock(&torture_rwlock);
}
static int torture_rwlock_read_lock(void) __acquires(torture_rwlock)
static int torture_rwlock_read_lock(int tid __maybe_unused)
__acquires(torture_rwlock)
{
read_lock(&torture_rwlock);
return 0;
@@ -261,7 +266,8 @@ static void torture_rwlock_read_delay(struct torture_random_state *trsp)
udelay(shortdelay_us);
}
static void torture_rwlock_read_unlock(void) __releases(torture_rwlock)
static void torture_rwlock_read_unlock(int tid __maybe_unused)
__releases(torture_rwlock)
{
read_unlock(&torture_rwlock);
}
@@ -277,7 +283,8 @@ static struct lock_torture_ops rw_lock_ops = {
.name = "rw_lock"
};
static int torture_rwlock_write_lock_irq(void) __acquires(torture_rwlock)
static int torture_rwlock_write_lock_irq(int tid __maybe_unused)
__acquires(torture_rwlock)
{
unsigned long flags;
@@ -286,13 +293,14 @@ static int torture_rwlock_write_lock_irq(void) __acquires(torture_rwlock)
return 0;
}
static void torture_rwlock_write_unlock_irq(void)
static void torture_rwlock_write_unlock_irq(int tid __maybe_unused)
__releases(torture_rwlock)
{
write_unlock_irqrestore(&torture_rwlock, cxt.cur_ops->flags);
}
static int torture_rwlock_read_lock_irq(void) __acquires(torture_rwlock)
static int torture_rwlock_read_lock_irq(int tid __maybe_unused)
__acquires(torture_rwlock)
{
unsigned long flags;
@@ -301,7 +309,7 @@ static int torture_rwlock_read_lock_irq(void) __acquires(torture_rwlock)
return 0;
}
static void torture_rwlock_read_unlock_irq(void)
static void torture_rwlock_read_unlock_irq(int tid __maybe_unused)
__releases(torture_rwlock)
{
read_unlock_irqrestore(&torture_rwlock, cxt.cur_ops->flags);
@@ -320,7 +328,8 @@ static struct lock_torture_ops rw_lock_irq_ops = {
static DEFINE_MUTEX(torture_mutex);
static int torture_mutex_lock(void) __acquires(torture_mutex)
static int torture_mutex_lock(int tid __maybe_unused)
__acquires(torture_mutex)
{
mutex_lock(&torture_mutex);
return 0;
@@ -340,7 +349,8 @@ static void torture_mutex_delay(struct torture_random_state *trsp)
torture_preempt_schedule(); /* Allow test to be preempted. */
}
static void torture_mutex_unlock(void) __releases(torture_mutex)
static void torture_mutex_unlock(int tid __maybe_unused)
__releases(torture_mutex)
{
mutex_unlock(&torture_mutex);
}
@@ -357,12 +367,34 @@ static struct lock_torture_ops mutex_lock_ops = {
};
#include <linux/ww_mutex.h>
/*
* The torture ww_mutexes should belong to the same lock class as
* torture_ww_class to avoid lockdep problem. The ww_mutex_init()
* function is called for initialization to ensure that.
*/
static DEFINE_WD_CLASS(torture_ww_class);
static DEFINE_WW_MUTEX(torture_ww_mutex_0, &torture_ww_class);
static DEFINE_WW_MUTEX(torture_ww_mutex_1, &torture_ww_class);
static DEFINE_WW_MUTEX(torture_ww_mutex_2, &torture_ww_class);
static struct ww_mutex torture_ww_mutex_0, torture_ww_mutex_1, torture_ww_mutex_2;
static struct ww_acquire_ctx *ww_acquire_ctxs;
static int torture_ww_mutex_lock(void)
static void torture_ww_mutex_init(void)
{
ww_mutex_init(&torture_ww_mutex_0, &torture_ww_class);
ww_mutex_init(&torture_ww_mutex_1, &torture_ww_class);
ww_mutex_init(&torture_ww_mutex_2, &torture_ww_class);
ww_acquire_ctxs = kmalloc_array(cxt.nrealwriters_stress,
sizeof(*ww_acquire_ctxs),
GFP_KERNEL);
if (!ww_acquire_ctxs)
VERBOSE_TOROUT_STRING("ww_acquire_ctx: Out of memory");
}
static void torture_ww_mutex_exit(void)
{
kfree(ww_acquire_ctxs);
}
static int torture_ww_mutex_lock(int tid)
__acquires(torture_ww_mutex_0)
__acquires(torture_ww_mutex_1)
__acquires(torture_ww_mutex_2)
@@ -372,7 +404,7 @@ __acquires(torture_ww_mutex_2)
struct list_head link;
struct ww_mutex *lock;
} locks[3], *ll, *ln;
struct ww_acquire_ctx ctx;
struct ww_acquire_ctx *ctx = &ww_acquire_ctxs[tid];
locks[0].lock = &torture_ww_mutex_0;
list_add(&locks[0].link, &list);
@@ -383,12 +415,12 @@ __acquires(torture_ww_mutex_2)
locks[2].lock = &torture_ww_mutex_2;
list_add(&locks[2].link, &list);
ww_acquire_init(&ctx, &torture_ww_class);
ww_acquire_init(ctx, &torture_ww_class);
list_for_each_entry(ll, &list, link) {
int err;
err = ww_mutex_lock(ll->lock, &ctx);
err = ww_mutex_lock(ll->lock, ctx);
if (!err)
continue;
@@ -399,25 +431,29 @@ __acquires(torture_ww_mutex_2)
if (err != -EDEADLK)
return err;
ww_mutex_lock_slow(ll->lock, &ctx);
ww_mutex_lock_slow(ll->lock, ctx);
list_move(&ll->link, &list);
}
ww_acquire_fini(&ctx);
return 0;
}
static void torture_ww_mutex_unlock(void)
static void torture_ww_mutex_unlock(int tid)
__releases(torture_ww_mutex_0)
__releases(torture_ww_mutex_1)
__releases(torture_ww_mutex_2)
{
struct ww_acquire_ctx *ctx = &ww_acquire_ctxs[tid];
ww_mutex_unlock(&torture_ww_mutex_0);
ww_mutex_unlock(&torture_ww_mutex_1);
ww_mutex_unlock(&torture_ww_mutex_2);
ww_acquire_fini(ctx);
}
static struct lock_torture_ops ww_mutex_lock_ops = {
.init = torture_ww_mutex_init,
.exit = torture_ww_mutex_exit,
.writelock = torture_ww_mutex_lock,
.write_delay = torture_mutex_delay,
.task_boost = torture_boost_dummy,
@@ -431,7 +467,8 @@ static struct lock_torture_ops ww_mutex_lock_ops = {
#ifdef CONFIG_RT_MUTEXES
static DEFINE_RT_MUTEX(torture_rtmutex);
static int torture_rtmutex_lock(void) __acquires(torture_rtmutex)
static int torture_rtmutex_lock(int tid __maybe_unused)
__acquires(torture_rtmutex)
{
rt_mutex_lock(&torture_rtmutex);
return 0;
@@ -487,7 +524,8 @@ static void torture_rtmutex_delay(struct torture_random_state *trsp)
torture_preempt_schedule(); /* Allow test to be preempted. */
}
static void torture_rtmutex_unlock(void) __releases(torture_rtmutex)
static void torture_rtmutex_unlock(int tid __maybe_unused)
__releases(torture_rtmutex)
{
rt_mutex_unlock(&torture_rtmutex);
}
@@ -505,7 +543,8 @@ static struct lock_torture_ops rtmutex_lock_ops = {
#endif
static DECLARE_RWSEM(torture_rwsem);
static int torture_rwsem_down_write(void) __acquires(torture_rwsem)
static int torture_rwsem_down_write(int tid __maybe_unused)
__acquires(torture_rwsem)
{
down_write(&torture_rwsem);
return 0;
@@ -525,12 +564,14 @@ static void torture_rwsem_write_delay(struct torture_random_state *trsp)
torture_preempt_schedule(); /* Allow test to be preempted. */
}
static void torture_rwsem_up_write(void) __releases(torture_rwsem)
static void torture_rwsem_up_write(int tid __maybe_unused)
__releases(torture_rwsem)
{
up_write(&torture_rwsem);
}
static int torture_rwsem_down_read(void) __acquires(torture_rwsem)
static int torture_rwsem_down_read(int tid __maybe_unused)
__acquires(torture_rwsem)
{
down_read(&torture_rwsem);
return 0;
@@ -550,7 +591,8 @@ static void torture_rwsem_read_delay(struct torture_random_state *trsp)
torture_preempt_schedule(); /* Allow test to be preempted. */
}
static void torture_rwsem_up_read(void) __releases(torture_rwsem)
static void torture_rwsem_up_read(int tid __maybe_unused)
__releases(torture_rwsem)
{
up_read(&torture_rwsem);
}
@@ -579,24 +621,28 @@ static void torture_percpu_rwsem_exit(void)
percpu_free_rwsem(&pcpu_rwsem);
}
static int torture_percpu_rwsem_down_write(void) __acquires(pcpu_rwsem)
static int torture_percpu_rwsem_down_write(int tid __maybe_unused)
__acquires(pcpu_rwsem)
{
percpu_down_write(&pcpu_rwsem);
return 0;
}
static void torture_percpu_rwsem_up_write(void) __releases(pcpu_rwsem)
static void torture_percpu_rwsem_up_write(int tid __maybe_unused)
__releases(pcpu_rwsem)
{
percpu_up_write(&pcpu_rwsem);
}
static int torture_percpu_rwsem_down_read(void) __acquires(pcpu_rwsem)
static int torture_percpu_rwsem_down_read(int tid __maybe_unused)
__acquires(pcpu_rwsem)
{
percpu_down_read(&pcpu_rwsem);
return 0;
}
static void torture_percpu_rwsem_up_read(void) __releases(pcpu_rwsem)
static void torture_percpu_rwsem_up_read(int tid __maybe_unused)
__releases(pcpu_rwsem)
{
percpu_up_read(&pcpu_rwsem);
}
@@ -621,6 +667,7 @@ static struct lock_torture_ops percpu_rwsem_lock_ops = {
static int lock_torture_writer(void *arg)
{
struct lock_stress_stats *lwsp = arg;
int tid = lwsp - cxt.lwsa;
DEFINE_TORTURE_RANDOM(rand);
VERBOSE_TOROUT_STRING("lock_torture_writer task started");
@@ -631,7 +678,7 @@ static int lock_torture_writer(void *arg)
schedule_timeout_uninterruptible(1);
cxt.cur_ops->task_boost(&rand);
cxt.cur_ops->writelock();
cxt.cur_ops->writelock(tid);
if (WARN_ON_ONCE(lock_is_write_held))
lwsp->n_lock_fail++;
lock_is_write_held = true;
@@ -642,7 +689,7 @@ static int lock_torture_writer(void *arg)
cxt.cur_ops->write_delay(&rand);
lock_is_write_held = false;
WRITE_ONCE(last_lock_release, jiffies);
cxt.cur_ops->writeunlock();
cxt.cur_ops->writeunlock(tid);
stutter_wait("lock_torture_writer");
} while (!torture_must_stop());
@@ -659,6 +706,7 @@ static int lock_torture_writer(void *arg)
static int lock_torture_reader(void *arg)
{
struct lock_stress_stats *lrsp = arg;
int tid = lrsp - cxt.lrsa;
DEFINE_TORTURE_RANDOM(rand);
VERBOSE_TOROUT_STRING("lock_torture_reader task started");
@@ -668,7 +716,7 @@ static int lock_torture_reader(void *arg)
if ((torture_random(&rand) & 0xfffff) == 0)
schedule_timeout_uninterruptible(1);
cxt.cur_ops->readlock();
cxt.cur_ops->readlock(tid);
lock_is_read_held = true;
if (WARN_ON_ONCE(lock_is_write_held))
lrsp->n_lock_fail++; /* rare, but... */
@@ -676,7 +724,7 @@ static int lock_torture_reader(void *arg)
lrsp->n_lock_acquired++;
cxt.cur_ops->read_delay(&rand);
lock_is_read_held = false;
cxt.cur_ops->readunlock();
cxt.cur_ops->readunlock(tid);
stutter_wait("lock_torture_reader");
} while (!torture_must_stop());
@@ -891,16 +939,16 @@ static int __init lock_torture_init(void)
goto unwind;
}
if (cxt.cur_ops->init) {
cxt.cur_ops->init();
cxt.init_called = true;
}
if (nwriters_stress >= 0)
cxt.nrealwriters_stress = nwriters_stress;
else
cxt.nrealwriters_stress = 2 * num_online_cpus();
if (cxt.cur_ops->init) {
cxt.cur_ops->init();
cxt.init_called = true;
}
#ifdef CONFIG_DEBUG_MUTEXES
if (str_has_prefix(torture_type, "mutex"))
cxt.debug_lock = true;

2
kernel/locking/mcs_spinlock.h
View File

@@ -7,7 +7,7 @@
* The MCS lock (proposed by Mellor-Crummey and Scott) is a simple spin-lock
* with the desirable properties of being fair, and with each cpu trying
* to acquire the lock spinning on a local variable.
* It avoids expensive cache bouncings that common test-and-set spin-lock
* It avoids expensive cache bounces that common test-and-set spin-lock
* implementations incur.
*/
#ifndef __LINUX_MCS_SPINLOCK_H

4
kernel/locking/mutex.c
View File

@@ -92,7 +92,7 @@ static inline unsigned long __owner_flags(unsigned long owner)
}
/*
* Trylock variant that retuns the owning task on failure.
* Trylock variant that returns the owning task on failure.
*/
static inline struct task_struct *__mutex_trylock_or_owner(struct mutex *lock)
{
@@ -207,7 +207,7 @@ __mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter,
/*
* Give up ownership to a specific task, when @task = NULL, this is equivalent
* to a regular unlock. Sets PICKUP on a handoff, clears HANDOF, preserves
* to a regular unlock. Sets PICKUP on a handoff, clears HANDOFF, preserves
* WAITERS. Provides RELEASE semantics like a regular unlock, the
* __mutex_trylock() provides a matching ACQUIRE semantics for the handoff.
*/

4
kernel/locking/osq_lock.c
View File

@@ -135,7 +135,7 @@ bool osq_lock(struct optimistic_spin_queue *lock)
*/
/*
* Wait to acquire the lock or cancelation. Note that need_resched()
* Wait to acquire the lock or cancellation. Note that need_resched()
* will come with an IPI, which will wake smp_cond_load_relaxed() if it
* is implemented with a monitor-wait. vcpu_is_preempted() relies on
* polling, be careful.
@@ -164,7 +164,7 @@ bool osq_lock(struct optimistic_spin_queue *lock)
/*
* We can only fail the cmpxchg() racing against an unlock(),
* in which case we should observe @node->locked becomming
* in which case we should observe @node->locked becoming
* true.
*/
if (smp_load_acquire(&node->locked))

182
kernel/locking/rtmutex-debug.c
View File

@@ -1,182 +0,0 @@
// SPDX-License-Identifier: GPL-2.0
/*
* RT-Mutexes: blocking mutual exclusion locks with PI support
*
* started by Ingo Molnar and Thomas Gleixner:
*
* Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
* Copyright (C) 2006 Timesys Corp., Thomas Gleixner <tglx@timesys.com>
*
* This code is based on the rt.c implementation in the preempt-rt tree.
* Portions of said code are
*
* Copyright (C) 2004 LynuxWorks, Inc., Igor Manyilov, Bill Huey
* Copyright (C) 2006 Esben Nielsen
* Copyright (C) 2006 Kihon Technologies Inc.,
* Steven Rostedt <rostedt@goodmis.org>
*
* See rt.c in preempt-rt for proper credits and further information
*/
#include <linux/sched.h>
#include <linux/sched/rt.h>
#include <linux/sched/debug.h>
#include <linux/delay.h>
#include <linux/export.h>
#include <linux/spinlock.h>
#include <linux/kallsyms.h>
#include <linux/syscalls.h>
#include <linux/interrupt.h>
#include <linux/rbtree.h>
#include <linux/fs.h>
#include <linux/debug_locks.h>
#include "rtmutex_common.h"
static void printk_task(struct task_struct *p)
{
if (p)
printk("%16s:%5d [%p, %3d]", p->comm, task_pid_nr(p), p, p->prio);
else
printk("<none>");
}
static void printk_lock(struct rt_mutex *lock, int print_owner)
{
if (lock->name)
printk(" [%p] {%s}\n",
lock, lock->name);
else
printk(" [%p] {%s:%d}\n",
lock, lock->file, lock->line);
if (print_owner && rt_mutex_owner(lock)) {
printk(".. ->owner: %p\n", lock->owner);
printk(".. held by: ");
printk_task(rt_mutex_owner(lock));
printk("\n");
}
}
void rt_mutex_debug_task_free(struct task_struct *task)
{
DEBUG_LOCKS_WARN_ON(!RB_EMPTY_ROOT(&task->pi_waiters.rb_root));
DEBUG_LOCKS_WARN_ON(task->pi_blocked_on);
}
/*
* We fill out the fields in the waiter to store the information about
* the deadlock. We print when we return. act_waiter can be NULL in
* case of a remove waiter operation.
*/
void debug_rt_mutex_deadlock(enum rtmutex_chainwalk chwalk,
struct rt_mutex_waiter *act_waiter,
struct rt_mutex *lock)
{
struct task_struct *task;
if (!debug_locks || chwalk == RT_MUTEX_FULL_CHAINWALK || !act_waiter)
return;
task = rt_mutex_owner(act_waiter->lock);
if (task && task != current) {
act_waiter->deadlock_task_pid = get_pid(task_pid(task));
act_waiter->deadlock_lock = lock;
}
}
void debug_rt_mutex_print_deadlock(struct rt_mutex_waiter *waiter)
{
struct task_struct *task;
if (!waiter->deadlock_lock || !debug_locks)
return;
rcu_read_lock();
task = pid_task(waiter->deadlock_task_pid, PIDTYPE_PID);
if (!task) {
rcu_read_unlock();
return;
}
if (!debug_locks_off()) {
rcu_read_unlock();
return;
}
pr_warn("\n");
pr_warn("============================================\n");
pr_warn("WARNING: circular locking deadlock detected!\n");
pr_warn("%s\n", print_tainted());
pr_warn("--------------------------------------------\n");
printk("%s/%d is deadlocking current task %s/%d\n\n",
task->comm, task_pid_nr(task),
current->comm, task_pid_nr(current));
printk("\n1) %s/%d is trying to acquire this lock:\n",
current->comm, task_pid_nr(current));
printk_lock(waiter->lock, 1);
printk("\n2) %s/%d is blocked on this lock:\n",
task->comm, task_pid_nr(task));
printk_lock(waiter->deadlock_lock, 1);
debug_show_held_locks(current);
debug_show_held_locks(task);
printk("\n%s/%d's [blocked] stackdump:\n\n",
task->comm, task_pid_nr(task));
show_stack(task, NULL, KERN_DEFAULT);
printk("\n%s/%d's [current] stackdump:\n\n",
current->comm, task_pid_nr(current));
dump_stack();
debug_show_all_locks();
rcu_read_unlock();
printk("[ turning off deadlock detection."
"Please report this trace. ]\n\n");
}
void debug_rt_mutex_lock(struct rt_mutex *lock)
{
}
void debug_rt_mutex_unlock(struct rt_mutex *lock)
{
DEBUG_LOCKS_WARN_ON(rt_mutex_owner(lock) != current);
}
void
debug_rt_mutex_proxy_lock(struct rt_mutex *lock, struct task_struct *powner)
{
}
void debug_rt_mutex_proxy_unlock(struct rt_mutex *lock)
{
DEBUG_LOCKS_WARN_ON(!rt_mutex_owner(lock));
}
void debug_rt_mutex_init_waiter(struct rt_mutex_waiter *waiter)
{
memset(waiter, 0x11, sizeof(*waiter));
waiter->deadlock_task_pid = NULL;
}
void debug_rt_mutex_free_waiter(struct rt_mutex_waiter *waiter)
{
put_pid(waiter->deadlock_task_pid);
memset(waiter, 0x22, sizeof(*waiter));
}
void debug_rt_mutex_init(struct rt_mutex *lock, const char *name, struct lock_class_key *key)
{
/*
* Make sure we are not reinitializing a held lock:
*/
debug_check_no_locks_freed((void *)lock, sizeof(*lock));
lock->name = name;
#ifdef CONFIG_DEBUG_LOCK_ALLOC
lockdep_init_map(&lock->dep_map, name, key, 0);
#endif
}

37
kernel/locking/rtmutex-debug.h
View File

@@ -1,37 +0,0 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* RT-Mutexes: blocking mutual exclusion locks with PI support
*
* started by Ingo Molnar and Thomas Gleixner:
*
* Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
* Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
*
* This file contains macros used solely by rtmutex.c. Debug version.
*/
extern void debug_rt_mutex_init_waiter(struct rt_mutex_waiter *waiter);
extern void debug_rt_mutex_free_waiter(struct rt_mutex_waiter *waiter);
extern void debug_rt_mutex_init(struct rt_mutex *lock, const char *name, struct lock_class_key *key);
extern void debug_rt_mutex_lock(struct rt_mutex *lock);
extern void debug_rt_mutex_unlock(struct rt_mutex *lock);
extern void debug_rt_mutex_proxy_lock(struct rt_mutex *lock,
struct task_struct *powner);
extern void debug_rt_mutex_proxy_unlock(struct rt_mutex *lock);
extern void debug_rt_mutex_deadlock(enum rtmutex_chainwalk chwalk,
struct rt_mutex_waiter *waiter,
struct rt_mutex *lock);
extern void debug_rt_mutex_print_deadlock(struct rt_mutex_waiter *waiter);
# define debug_rt_mutex_reset_waiter(w) \
do { (w)->deadlock_lock = NULL; } while (0)
static inline bool debug_rt_mutex_detect_deadlock(struct rt_mutex_waiter *waiter,
enum rtmutex_chainwalk walk)
{
return (waiter != NULL);
}
static inline void rt_mutex_print_deadlock(struct rt_mutex_waiter *w)
{
debug_rt_mutex_print_deadlock(w);
}

434
kernel/locking/rtmutex.c
View File

@@ -49,7 +49,7 @@
* set this bit before looking at the lock.
*/
static void
static __always_inline void
rt_mutex_set_owner(struct rt_mutex *lock, struct task_struct *owner)
{
unsigned long val = (unsigned long)owner;
@@ -60,13 +60,13 @@ rt_mutex_set_owner(struct rt_mutex *lock, struct task_struct *owner)
WRITE_ONCE(lock->owner, (struct task_struct *)val);
}
static inline void clear_rt_mutex_waiters(struct rt_mutex *lock)
static __always_inline void clear_rt_mutex_waiters(struct rt_mutex *lock)
{
lock->owner = (struct task_struct *)
((unsigned long)lock->owner & ~RT_MUTEX_HAS_WAITERS);
}
static void fixup_rt_mutex_waiters(struct rt_mutex *lock)
static __always_inline void fixup_rt_mutex_waiters(struct rt_mutex *lock)
{
unsigned long owner, *p = (unsigned long *) &lock->owner;
@@ -149,7 +149,7 @@ static void fixup_rt_mutex_waiters(struct rt_mutex *lock)
* all future threads that attempt to [Rmw] the lock to the slowpath. As such
* relaxed semantics suffice.
*/
static inline void mark_rt_mutex_waiters(struct rt_mutex *lock)
static __always_inline void mark_rt_mutex_waiters(struct rt_mutex *lock)
{
unsigned long owner, *p = (unsigned long *) &lock->owner;
@@ -165,8 +165,8 @@ static inline void mark_rt_mutex_waiters(struct rt_mutex *lock)
* 2) Drop lock->wait_lock
* 3) Try to unlock the lock with cmpxchg
*/
static inline bool unlock_rt_mutex_safe(struct rt_mutex *lock,
unsigned long flags)
static __always_inline bool unlock_rt_mutex_safe(struct rt_mutex *lock,
unsigned long flags)
__releases(lock->wait_lock)
{
struct task_struct *owner = rt_mutex_owner(lock);
@@ -204,7 +204,7 @@ static inline bool unlock_rt_mutex_safe(struct rt_mutex *lock,
# define rt_mutex_cmpxchg_acquire(l,c,n) (0)
# define rt_mutex_cmpxchg_release(l,c,n) (0)
static inline void mark_rt_mutex_waiters(struct rt_mutex *lock)
static __always_inline void mark_rt_mutex_waiters(struct rt_mutex *lock)
{
lock->owner = (struct task_struct *)
((unsigned long)lock->owner | RT_MUTEX_HAS_WAITERS);
@@ -213,8 +213,8 @@ static inline void mark_rt_mutex_waiters(struct rt_mutex *lock)
/*
* Simple slow path only version: lock->owner is protected by lock->wait_lock.
*/
static inline bool unlock_rt_mutex_safe(struct rt_mutex *lock,
unsigned long flags)
static __always_inline bool unlock_rt_mutex_safe(struct rt_mutex *lock,
unsigned long flags)
__releases(lock->wait_lock)
{
lock->owner = NULL;
@@ -229,9 +229,8 @@ static inline bool unlock_rt_mutex_safe(struct rt_mutex *lock,
#define task_to_waiter(p) \
&(struct rt_mutex_waiter){ .prio = (p)->prio, .deadline = (p)->dl.deadline }
static inline int
rt_mutex_waiter_less(struct rt_mutex_waiter *left,
struct rt_mutex_waiter *right)
static __always_inline int rt_mutex_waiter_less(struct rt_mutex_waiter *left,
struct rt_mutex_waiter *right)
{
if (left->prio < right->prio)
return 1;
@@ -248,9 +247,8 @@ rt_mutex_waiter_less(struct rt_mutex_waiter *left,
return 0;
}
static inline int
rt_mutex_waiter_equal(struct rt_mutex_waiter *left,
struct rt_mutex_waiter *right)
static __always_inline int rt_mutex_waiter_equal(struct rt_mutex_waiter *left,
struct rt_mutex_waiter *right)
{
if (left->prio != right->prio)
return 0;
@@ -270,18 +268,18 @@ rt_mutex_waiter_equal(struct rt_mutex_waiter *left,
#define __node_2_waiter(node) \
rb_entry((node), struct rt_mutex_waiter, tree_entry)
static inline bool __waiter_less(struct rb_node *a, const struct rb_node *b)
static __always_inline bool __waiter_less(struct rb_node *a, const struct rb_node *b)
{
return rt_mutex_waiter_less(__node_2_waiter(a), __node_2_waiter(b));
}
static void
static __always_inline void
rt_mutex_enqueue(struct rt_mutex *lock, struct rt_mutex_waiter *waiter)
{
rb_add_cached(&waiter->tree_entry, &lock->waiters, __waiter_less);
}
static void
static __always_inline void
rt_mutex_dequeue(struct rt_mutex *lock, struct rt_mutex_waiter *waiter)
{
if (RB_EMPTY_NODE(&waiter->tree_entry))
@@ -294,18 +292,19 @@ rt_mutex_dequeue(struct rt_mutex *lock, struct rt_mutex_waiter *waiter)
#define __node_2_pi_waiter(node) \
rb_entry((node), struct rt_mutex_waiter, pi_tree_entry)
static inline bool __pi_waiter_less(struct rb_node *a, const struct rb_node *b)
static __always_inline bool
__pi_waiter_less(struct rb_node *a, const struct rb_node *b)
{
return rt_mutex_waiter_less(__node_2_pi_waiter(a), __node_2_pi_waiter(b));
}
static void
static __always_inline void
rt_mutex_enqueue_pi(struct task_struct *task, struct rt_mutex_waiter *waiter)
{
rb_add_cached(&waiter->pi_tree_entry, &task->pi_waiters, __pi_waiter_less);
}
static void
static __always_inline void
rt_mutex_dequeue_pi(struct task_struct *task, struct rt_mutex_waiter *waiter)
{
if (RB_EMPTY_NODE(&waiter->pi_tree_entry))
@@ -315,7 +314,7 @@ rt_mutex_dequeue_pi(struct task_struct *task, struct rt_mutex_waiter *waiter)
RB_CLEAR_NODE(&waiter->pi_tree_entry);
}
static void rt_mutex_adjust_prio(struct task_struct *p)
static __always_inline void rt_mutex_adjust_prio(struct task_struct *p)
{
struct task_struct *pi_task = NULL;
@@ -340,17 +339,13 @@ static void rt_mutex_adjust_prio(struct task_struct *p)
* deadlock detection is disabled independent of the detect argument
* and the config settings.
*/
static bool rt_mutex_cond_detect_deadlock(struct rt_mutex_waiter *waiter,
enum rtmutex_chainwalk chwalk)
static __always_inline bool
rt_mutex_cond_detect_deadlock(struct rt_mutex_waiter *waiter,
enum rtmutex_chainwalk chwalk)
{
/*
* This is just a wrapper function for the following call,
* because debug_rt_mutex_detect_deadlock() smells like a magic
* debug feature and I wanted to keep the cond function in the
* main source file along with the comments instead of having
* two of the same in the headers.
*/
return debug_rt_mutex_detect_deadlock(waiter, chwalk);
if (IS_ENABLED(CONFIG_DEBUG_RT_MUTEX))
return waiter != NULL;
return chwalk == RT_MUTEX_FULL_CHAINWALK;
}
/*
@@ -358,7 +353,7 @@ static bool rt_mutex_cond_detect_deadlock(struct rt_mutex_waiter *waiter,
*/
int max_lock_depth = 1024;
static inline struct rt_mutex *task_blocked_on_lock(struct task_struct *p)
static __always_inline struct rt_mutex *task_blocked_on_lock(struct task_struct *p)
{
return p->pi_blocked_on ? p->pi_blocked_on->lock : NULL;
}
@@ -426,12 +421,12 @@ static inline struct rt_mutex *task_blocked_on_lock(struct task_struct *p)
* unlock(lock->wait_lock); release [L]
* goto again;
*/
static int rt_mutex_adjust_prio_chain(struct task_struct *task,
enum rtmutex_chainwalk chwalk,
struct rt_mutex *orig_lock,
struct rt_mutex *next_lock,
struct rt_mutex_waiter *orig_waiter,
struct task_struct *top_task)
static int __sched rt_mutex_adjust_prio_chain(struct task_struct *task,
enum rtmutex_chainwalk chwalk,
struct rt_mutex *orig_lock,
struct rt_mutex *next_lock,
struct rt_mutex_waiter *orig_waiter,
struct task_struct *top_task)
{
struct rt_mutex_waiter *waiter, *top_waiter = orig_waiter;
struct rt_mutex_waiter *prerequeue_top_waiter;
@@ -579,7 +574,6 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
* walk, we detected a deadlock.
*/
if (lock == orig_lock || rt_mutex_owner(lock) == top_task) {
debug_rt_mutex_deadlock(chwalk, orig_waiter, lock);
raw_spin_unlock(&lock->wait_lock);
ret = -EDEADLK;
goto out_unlock_pi;
@@ -706,7 +700,7 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
} else if (prerequeue_top_waiter == waiter) {
/*
* The waiter was the top waiter on the lock, but is
* no longer the top prority waiter. Replace waiter in
* no longer the top priority waiter. Replace waiter in
* the owner tasks pi waiters tree with the new top
* (highest priority) waiter and adjust the priority
* of the owner.
@@ -784,8 +778,9 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
* @waiter: The waiter that is queued to the lock's wait tree if the
* callsite called task_blocked_on_lock(), otherwise NULL
*/
static int try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
struct rt_mutex_waiter *waiter)
static int __sched
try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
struct rt_mutex_waiter *waiter)
{
lockdep_assert_held(&lock->wait_lock);
@@ -886,9 +881,6 @@ static int try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
raw_spin_unlock(&task->pi_lock);
takeit:
/* We got the lock. */
debug_rt_mutex_lock(lock);
/*
* This either preserves the RT_MUTEX_HAS_WAITERS bit if there
* are still waiters or clears it.
@@ -905,10 +897,10 @@ takeit:
*
* This must be called with lock->wait_lock held and interrupts disabled
*/
static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
struct rt_mutex_waiter *waiter,
struct task_struct *task,
enum rtmutex_chainwalk chwalk)
static int __sched task_blocks_on_rt_mutex(struct rt_mutex *lock,
struct rt_mutex_waiter *waiter,
struct task_struct *task,
enum rtmutex_chainwalk chwalk)
{
struct task_struct *owner = rt_mutex_owner(lock);
struct rt_mutex_waiter *top_waiter = waiter;
@@ -994,8 +986,8 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
*
* Called with lock->wait_lock held and interrupts disabled.
*/
static void mark_wakeup_next_waiter(struct wake_q_head *wake_q,
struct rt_mutex *lock)
static void __sched mark_wakeup_next_waiter(struct wake_q_head *wake_q,
struct rt_mutex *lock)
{
struct rt_mutex_waiter *waiter;
@@ -1044,8 +1036,8 @@ static void mark_wakeup_next_waiter(struct wake_q_head *wake_q,
* Must be called with lock->wait_lock held and interrupts disabled. I must
* have just failed to try_to_take_rt_mutex().
*/
static void remove_waiter(struct rt_mutex *lock,
struct rt_mutex_waiter *waiter)
static void __sched remove_waiter(struct rt_mutex *lock,
struct rt_mutex_waiter *waiter)
{
bool is_top_waiter = (waiter == rt_mutex_top_waiter(lock));
struct task_struct *owner = rt_mutex_owner(lock);
@@ -1102,7 +1094,7 @@ static void remove_waiter(struct rt_mutex *lock,
*
* Called from sched_setscheduler
*/
void rt_mutex_adjust_pi(struct task_struct *task)
void __sched rt_mutex_adjust_pi(struct task_struct *task)
{
struct rt_mutex_waiter *waiter;
struct rt_mutex *next_lock;
@@ -1125,7 +1117,7 @@ void rt_mutex_adjust_pi(struct task_struct *task)
next_lock, NULL, task);
}
void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter)
void __sched rt_mutex_init_waiter(struct rt_mutex_waiter *waiter)
{
debug_rt_mutex_init_waiter(waiter);
RB_CLEAR_NODE(&waiter->pi_tree_entry);
@@ -1143,10 +1135,9 @@ void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter)
*
* Must be called with lock->wait_lock held and interrupts disabled
*/
static int __sched
__rt_mutex_slowlock(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
struct rt_mutex_waiter *waiter)
static int __sched __rt_mutex_slowlock(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
struct rt_mutex_waiter *waiter)
{
int ret = 0;
@@ -1155,24 +1146,17 @@ __rt_mutex_slowlock(struct rt_mutex *lock, int state,
if (try_to_take_rt_mutex(lock, current, waiter))
break;
/*
* TASK_INTERRUPTIBLE checks for signals and
* timeout. Ignored otherwise.
*/
if (likely(state == TASK_INTERRUPTIBLE)) {
/* Signal pending? */
if (signal_pending(current))
ret = -EINTR;
if (timeout && !timeout->task)
ret = -ETIMEDOUT;
if (ret)
break;
if (timeout && !timeout->task) {
ret = -ETIMEDOUT;
break;
}
if (signal_pending_state(state, current)) {
ret = -EINTR;
break;
}
raw_spin_unlock_irq(&lock->wait_lock);
debug_rt_mutex_print_deadlock(waiter);
schedule();
raw_spin_lock_irq(&lock->wait_lock);
@@ -1183,8 +1167,8 @@ __rt_mutex_slowlock(struct rt_mutex *lock, int state,
return ret;
}
static void rt_mutex_handle_deadlock(int res, int detect_deadlock,
struct rt_mutex_waiter *w)
static void __sched rt_mutex_handle_deadlock(int res, int detect_deadlock,
struct rt_mutex_waiter *w)
{
/*
* If the result is not -EDEADLOCK or the caller requested
@@ -1194,9 +1178,9 @@ static void rt_mutex_handle_deadlock(int res, int detect_deadlock,
return;
/*
* Yell lowdly and stop the task right here.
* Yell loudly and stop the task right here.
*/
rt_mutex_print_deadlock(w);
WARN(1, "rtmutex deadlock detected\n");
while (1) {
set_current_state(TASK_INTERRUPTIBLE);
schedule();
@@ -1206,10 +1190,9 @@ static void rt_mutex_handle_deadlock(int res, int detect_deadlock,
/*
* Slow path lock function:
*/
static int __sched
rt_mutex_slowlock(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
enum rtmutex_chainwalk chwalk)
static int __sched rt_mutex_slowlock(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
enum rtmutex_chainwalk chwalk)
{
struct rt_mutex_waiter waiter;
unsigned long flags;
@@ -1268,7 +1251,7 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
return ret;
}
static inline int __rt_mutex_slowtrylock(struct rt_mutex *lock)
static int __sched __rt_mutex_slowtrylock(struct rt_mutex *lock)
{
int ret = try_to_take_rt_mutex(lock, current, NULL);
@@ -1284,7 +1267,7 @@ static inline int __rt_mutex_slowtrylock(struct rt_mutex *lock)
/*
* Slow path try-lock function:
*/
static inline int rt_mutex_slowtrylock(struct rt_mutex *lock)
static int __sched rt_mutex_slowtrylock(struct rt_mutex *lock)
{
unsigned long flags;
int ret;
@@ -1310,14 +1293,25 @@ static inline int rt_mutex_slowtrylock(struct rt_mutex *lock)
return ret;
}
/*
* Performs the wakeup of the top-waiter and re-enables preemption.
*/
void __sched rt_mutex_postunlock(struct wake_q_head *wake_q)
{
wake_up_q(wake_q);
/* Pairs with preempt_disable() in mark_wakeup_next_waiter() */
preempt_enable();
}
/*
* Slow path to release a rt-mutex.
*
* Return whether the current task needs to call rt_mutex_postunlock().
*/
static bool __sched rt_mutex_slowunlock(struct rt_mutex *lock,
struct wake_q_head *wake_q)
static void __sched rt_mutex_slowunlock(struct rt_mutex *lock)
{
DEFINE_WAKE_Q(wake_q);
unsigned long flags;
/* irqsave required to support early boot calls */
@@ -1359,7 +1353,7 @@ static bool __sched rt_mutex_slowunlock(struct rt_mutex *lock,
while (!rt_mutex_has_waiters(lock)) {
/* Drops lock->wait_lock ! */
if (unlock_rt_mutex_safe(lock, flags) == true)
return false;
return;
/* Relock the rtmutex and try again */
raw_spin_lock_irqsave(&lock->wait_lock, flags);
}
@@ -1370,10 +1364,10 @@ static bool __sched rt_mutex_slowunlock(struct rt_mutex *lock,
*
* Queue the next waiter for wakeup once we release the wait_lock.
*/
mark_wakeup_next_waiter(wake_q, lock);
mark_wakeup_next_waiter(&wake_q, lock);
raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
return true; /* call rt_mutex_postunlock() */
rt_mutex_postunlock(&wake_q);
}
/*
@@ -1382,74 +1376,21 @@ static bool __sched rt_mutex_slowunlock(struct rt_mutex *lock,
* The atomic acquire/release ops are compiled away, when either the
* architecture does not support cmpxchg or when debugging is enabled.
*/
static inline int
rt_mutex_fastlock(struct rt_mutex *lock, int state,
int (*slowfn)(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
enum rtmutex_chainwalk chwalk))
static __always_inline int __rt_mutex_lock(struct rt_mutex *lock, long state,
unsigned int subclass)
{
if (likely(rt_mutex_cmpxchg_acquire(lock, NULL, current)))
return 0;
int ret;
return slowfn(lock, state, NULL, RT_MUTEX_MIN_CHAINWALK);
}
static inline int
rt_mutex_timed_fastlock(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
enum rtmutex_chainwalk chwalk,
int (*slowfn)(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
enum rtmutex_chainwalk chwalk))
{
if (chwalk == RT_MUTEX_MIN_CHAINWALK &&
likely(rt_mutex_cmpxchg_acquire(lock, NULL, current)))
return 0;
return slowfn(lock, state, timeout, chwalk);
}
static inline int
rt_mutex_fasttrylock(struct rt_mutex *lock,
int (*slowfn)(struct rt_mutex *lock))
{
if (likely(rt_mutex_cmpxchg_acquire(lock, NULL, current)))
return 1;
return slowfn(lock);
}
/*
* Performs the wakeup of the top-waiter and re-enables preemption.
*/
void rt_mutex_postunlock(struct wake_q_head *wake_q)
{
wake_up_q(wake_q);
/* Pairs with preempt_disable() in rt_mutex_slowunlock() */
preempt_enable();
}
static inline void
rt_mutex_fastunlock(struct rt_mutex *lock,
bool (*slowfn)(struct rt_mutex *lock,
struct wake_q_head *wqh))
{
DEFINE_WAKE_Q(wake_q);
if (likely(rt_mutex_cmpxchg_release(lock, current, NULL)))
return;
if (slowfn(lock, &wake_q))
rt_mutex_postunlock(&wake_q);
}
static inline void __rt_mutex_lock(struct rt_mutex *lock, unsigned int subclass)
{
might_sleep();
mutex_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
rt_mutex_fastlock(lock, TASK_UNINTERRUPTIBLE, rt_mutex_slowlock);
if (likely(rt_mutex_cmpxchg_acquire(lock, NULL, current)))
return 0;
ret = rt_mutex_slowlock(lock, state, NULL, RT_MUTEX_MIN_CHAINWALK);
if (ret)
mutex_release(&lock->dep_map, _RET_IP_);
return ret;
}
#ifdef CONFIG_DEBUG_LOCK_ALLOC
@@ -1461,7 +1402,7 @@ static inline void __rt_mutex_lock(struct rt_mutex *lock, unsigned int subclass)
*/
void __sched rt_mutex_lock_nested(struct rt_mutex *lock, unsigned int subclass)
{
__rt_mutex_lock(lock, subclass);
__rt_mutex_lock(lock, TASK_UNINTERRUPTIBLE, subclass);
}
EXPORT_SYMBOL_GPL(rt_mutex_lock_nested);
@@ -1474,7 +1415,7 @@ EXPORT_SYMBOL_GPL(rt_mutex_lock_nested);
*/
void __sched rt_mutex_lock(struct rt_mutex *lock)
{
__rt_mutex_lock(lock, 0);
__rt_mutex_lock(lock, TASK_UNINTERRUPTIBLE, 0);
}
EXPORT_SYMBOL_GPL(rt_mutex_lock);
#endif
@@ -1490,82 +1431,37 @@ EXPORT_SYMBOL_GPL(rt_mutex_lock);
*/
int __sched rt_mutex_lock_interruptible(struct rt_mutex *lock)
{
int ret;
might_sleep();
mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
ret = rt_mutex_fastlock(lock, TASK_INTERRUPTIBLE, rt_mutex_slowlock);
if (ret)
mutex_release(&lock->dep_map, _RET_IP_);
return ret;
return __rt_mutex_lock(lock, TASK_INTERRUPTIBLE, 0);
}
EXPORT_SYMBOL_GPL(rt_mutex_lock_interruptible);
/*
* Futex variant, must not use fastpath.
*/
int __sched rt_mutex_futex_trylock(struct rt_mutex *lock)
{
return rt_mutex_slowtrylock(lock);
}
int __sched __rt_mutex_futex_trylock(struct rt_mutex *lock)
{
return __rt_mutex_slowtrylock(lock);
}
/**
* rt_mutex_timed_lock - lock a rt_mutex interruptible
* the timeout structure is provided
* by the caller
*
* @lock: the rt_mutex to be locked
* @timeout: timeout structure or NULL (no timeout)
*
* Returns:
* 0 on success
* -EINTR when interrupted by a signal
* -ETIMEDOUT when the timeout expired
*/
int
rt_mutex_timed_lock(struct rt_mutex *lock, struct hrtimer_sleeper *timeout)
{
int ret;
might_sleep();
mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
ret = rt_mutex_timed_fastlock(lock, TASK_INTERRUPTIBLE, timeout,
RT_MUTEX_MIN_CHAINWALK,
rt_mutex_slowlock);
if (ret)
mutex_release(&lock->dep_map, _RET_IP_);
return ret;
}
EXPORT_SYMBOL_GPL(rt_mutex_timed_lock);
/**
* rt_mutex_trylock - try to lock a rt_mutex
*
* @lock: the rt_mutex to be locked
*
* This function can only be called in thread context. It's safe to
* call it from atomic regions, but not from hard interrupt or soft
* interrupt context.
* This function can only be called in thread context. It's safe to call it
* from atomic regions, but not from hard or soft interrupt context.
*
* Returns 1 on success and 0 on contention
* Returns:
* 1 on success
* 0 on contention
*/
int __sched rt_mutex_trylock(struct rt_mutex *lock)
{
int ret;
if (WARN_ON_ONCE(in_irq() || in_nmi() || in_serving_softirq()))
if (IS_ENABLED(CONFIG_DEBUG_RT_MUTEXES) && WARN_ON_ONCE(!in_task()))
return 0;
ret = rt_mutex_fasttrylock(lock, rt_mutex_slowtrylock);
/*
* No lockdep annotation required because lockdep disables the fast
* path.
*/
if (likely(rt_mutex_cmpxchg_acquire(lock, NULL, current)))
return 1;
ret = rt_mutex_slowtrylock(lock);
if (ret)
mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_);
@@ -1581,10 +1477,26 @@ EXPORT_SYMBOL_GPL(rt_mutex_trylock);
void __sched rt_mutex_unlock(struct rt_mutex *lock)
{
mutex_release(&lock->dep_map, _RET_IP_);
rt_mutex_fastunlock(lock, rt_mutex_slowunlock);
if (likely(rt_mutex_cmpxchg_release(lock, current, NULL)))
return;
rt_mutex_slowunlock(lock);
}
EXPORT_SYMBOL_GPL(rt_mutex_unlock);
/*
* Futex variants, must not use fastpath.
*/
int __sched rt_mutex_futex_trylock(struct rt_mutex *lock)
{
return rt_mutex_slowtrylock(lock);
}
int __sched __rt_mutex_futex_trylock(struct rt_mutex *lock)
{
return __rt_mutex_slowtrylock(lock);
}
/**
* __rt_mutex_futex_unlock - Futex variant, that since futex variants
* do not use the fast-path, can be simple and will not need to retry.
@@ -1593,7 +1505,7 @@ EXPORT_SYMBOL_GPL(rt_mutex_unlock);
* @wake_q: The wake queue head from which to get the next lock waiter
*/
bool __sched __rt_mutex_futex_unlock(struct rt_mutex *lock,
struct wake_q_head *wake_q)
struct wake_q_head *wake_q)
{
lockdep_assert_held(&lock->wait_lock);
@@ -1629,23 +1541,6 @@ void __sched rt_mutex_futex_unlock(struct rt_mutex *lock)
rt_mutex_postunlock(&wake_q);
}
/**
* rt_mutex_destroy - mark a mutex unusable
* @lock: the mutex to be destroyed
*
* This function marks the mutex uninitialized, and any subsequent
* use of the mutex is forbidden. The mutex must not be locked when
* this function is called.
*/
void rt_mutex_destroy(struct rt_mutex *lock)
{
WARN_ON(rt_mutex_is_locked(lock));
#ifdef CONFIG_DEBUG_RT_MUTEXES
lock->magic = NULL;
#endif
}
EXPORT_SYMBOL_GPL(rt_mutex_destroy);
/**
* __rt_mutex_init - initialize the rt_mutex
*
@@ -1657,15 +1552,13 @@ EXPORT_SYMBOL_GPL(rt_mutex_destroy);
*
* Initializing of a locked rt_mutex is not allowed
*/
void __rt_mutex_init(struct rt_mutex *lock, const char *name,
void __sched __rt_mutex_init(struct rt_mutex *lock, const char *name,
struct lock_class_key *key)
{
lock->owner = NULL;
raw_spin_lock_init(&lock->wait_lock);
lock->waiters = RB_ROOT_CACHED;
debug_check_no_locks_freed((void *)lock, sizeof(*lock));
lockdep_init_map(&lock->dep_map, name, key, 0);
if (name && key)
debug_rt_mutex_init(lock, name, key);
__rt_mutex_basic_init(lock);
}
EXPORT_SYMBOL_GPL(__rt_mutex_init);
@@ -1683,11 +1576,10 @@ EXPORT_SYMBOL_GPL(__rt_mutex_init);
* possible at this point because the pi_state which contains the rtmutex
* is not yet visible to other tasks.
*/
void rt_mutex_init_proxy_locked(struct rt_mutex *lock,
struct task_struct *proxy_owner)
void __sched rt_mutex_init_proxy_locked(struct rt_mutex *lock,
struct task_struct *proxy_owner)
{
__rt_mutex_init(lock, NULL, NULL);
debug_rt_mutex_proxy_lock(lock, proxy_owner);
__rt_mutex_basic_init(lock);
rt_mutex_set_owner(lock, proxy_owner);
}
@@ -1703,7 +1595,7 @@ void rt_mutex_init_proxy_locked(struct rt_mutex *lock,
* possible because it belongs to the pi_state which is about to be freed
* and it is not longer visible to other tasks.
*/
void rt_mutex_proxy_unlock(struct rt_mutex *lock)
void __sched rt_mutex_proxy_unlock(struct rt_mutex *lock)
{
debug_rt_mutex_proxy_unlock(lock);
rt_mutex_set_owner(lock, NULL);
@@ -1728,9 +1620,9 @@ void rt_mutex_proxy_unlock(struct rt_mutex *lock)
*
* Special API call for PI-futex support.
*/
int __rt_mutex_start_proxy_lock(struct rt_mutex *lock,
struct rt_mutex_waiter *waiter,
struct task_struct *task)
int __sched __rt_mutex_start_proxy_lock(struct rt_mutex *lock,
struct rt_mutex_waiter *waiter,
struct task_struct *task)
{
int ret;
@@ -1753,8 +1645,6 @@ int __rt_mutex_start_proxy_lock(struct rt_mutex *lock,
ret = 0;
}
debug_rt_mutex_print_deadlock(waiter);
return ret;
}
@@ -1777,9 +1667,9 @@ int __rt_mutex_start_proxy_lock(struct rt_mutex *lock,
*
* Special API call for PI-futex support.
*/
int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
struct rt_mutex_waiter *waiter,
struct task_struct *task)
int __sched rt_mutex_start_proxy_lock(struct rt_mutex *lock,
struct rt_mutex_waiter *waiter,
struct task_struct *task)
{
int ret;
@@ -1792,26 +1682,6 @@ int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
return ret;
}
/**
* rt_mutex_next_owner - return the next owner of the lock
*
* @lock: the rt lock query
*
* Returns the next owner of the lock or NULL
*
* Caller has to serialize against other accessors to the lock
* itself.
*
* Special API call for PI-futex support
*/
struct task_struct *rt_mutex_next_owner(struct rt_mutex *lock)
{
if (!rt_mutex_has_waiters(lock))
return NULL;
return rt_mutex_top_waiter(lock)->task;
}
/**
* rt_mutex_wait_proxy_lock() - Wait for lock acquisition
* @lock: the rt_mutex we were woken on
@@ -1829,9 +1699,9 @@ struct task_struct *rt_mutex_next_owner(struct rt_mutex *lock)
*
* Special API call for PI-futex support
*/
int rt_mutex_wait_proxy_lock(struct rt_mutex *lock,
struct hrtimer_sleeper *to,
struct rt_mutex_waiter *waiter)
int __sched rt_mutex_wait_proxy_lock(struct rt_mutex *lock,
struct hrtimer_sleeper *to,
struct rt_mutex_waiter *waiter)
{
int ret;
@@ -1869,8 +1739,8 @@ int rt_mutex_wait_proxy_lock(struct rt_mutex *lock,
*
* Special API call for PI-futex support
*/
bool rt_mutex_cleanup_proxy_lock(struct rt_mutex *lock,
struct rt_mutex_waiter *waiter)
bool __sched rt_mutex_cleanup_proxy_lock(struct rt_mutex *lock,
struct rt_mutex_waiter *waiter)
{
bool cleanup = false;
@@ -1905,3 +1775,11 @@ bool rt_mutex_cleanup_proxy_lock(struct rt_mutex *lock,
return cleanup;
}
#ifdef CONFIG_DEBUG_RT_MUTEXES
void rt_mutex_debug_task_free(struct task_struct *task)
{
DEBUG_LOCKS_WARN_ON(!RB_EMPTY_ROOT(&task->pi_waiters.rb_root));
DEBUG_LOCKS_WARN_ON(task->pi_blocked_on);
}
#endif

35
kernel/locking/rtmutex.h
View File

@@ -1,35 +0,0 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* RT-Mutexes: blocking mutual exclusion locks with PI support
*
* started by Ingo Molnar and Thomas Gleixner:
*
* Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
* Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
*
* This file contains macros used solely by rtmutex.c.
* Non-debug version.
*/
#define rt_mutex_deadlock_check(l) (0)
#define debug_rt_mutex_init_waiter(w) do { } while (0)
#define debug_rt_mutex_free_waiter(w) do { } while (0)
#define debug_rt_mutex_lock(l) do { } while (0)
#define debug_rt_mutex_proxy_lock(l,p) do { } while (0)
#define debug_rt_mutex_proxy_unlock(l) do { } while (0)
#define debug_rt_mutex_unlock(l) do { } while (0)
#define debug_rt_mutex_init(m, n, k) do { } while (0)
#define debug_rt_mutex_deadlock(d, a ,l) do { } while (0)
#define debug_rt_mutex_print_deadlock(w) do { } while (0)
#define debug_rt_mutex_reset_waiter(w) do { } while (0)
static inline void rt_mutex_print_deadlock(struct rt_mutex_waiter *w)
{
WARN(1, "rtmutex deadlock detected\n");
}
static inline bool debug_rt_mutex_detect_deadlock(struct rt_mutex_waiter *w,
enum rtmutex_chainwalk walk)
{
return walk == RT_MUTEX_FULL_CHAINWALK;
}

105
kernel/locking/rtmutex_common.h
View File

@@ -13,6 +13,7 @@
#ifndef __KERNEL_RTMUTEX_COMMON_H
#define __KERNEL_RTMUTEX_COMMON_H
#include <linux/debug_locks.h>
#include <linux/rtmutex.h>
#include <linux/sched/wake_q.h>
@@ -23,34 +24,30 @@
* @tree_entry: pi node to enqueue into the mutex waiters tree
* @pi_tree_entry: pi node to enqueue into the mutex owner waiters tree
* @task: task reference to the blocked task
* @lock: Pointer to the rt_mutex on which the waiter blocks
* @prio: Priority of the waiter
* @deadline: Deadline of the waiter if applicable
*/
struct rt_mutex_waiter {
struct rb_node tree_entry;
struct rb_node pi_tree_entry;
struct rb_node tree_entry;
struct rb_node pi_tree_entry;
struct task_struct *task;
struct rt_mutex *lock;
#ifdef CONFIG_DEBUG_RT_MUTEXES
unsigned long ip;
struct pid *deadlock_task_pid;
struct rt_mutex *deadlock_lock;
#endif
int prio;
u64 deadline;
int prio;
u64 deadline;
};
/*
* Various helpers to access the waiters-tree:
* Must be guarded because this header is included from rcu/tree_plugin.h
* unconditionally.
*/
#ifdef CONFIG_RT_MUTEXES
static inline int rt_mutex_has_waiters(struct rt_mutex *lock)
{
return !RB_EMPTY_ROOT(&lock->waiters.rb_root);
}
static inline struct rt_mutex_waiter *
rt_mutex_top_waiter(struct rt_mutex *lock)
static inline struct rt_mutex_waiter *rt_mutex_top_waiter(struct rt_mutex *lock)
{
struct rb_node *leftmost = rb_first_cached(&lock->waiters);
struct rt_mutex_waiter *w = NULL;
@@ -67,42 +64,12 @@ static inline int task_has_pi_waiters(struct task_struct *p)
return !RB_EMPTY_ROOT(&p->pi_waiters.rb_root);
}
static inline struct rt_mutex_waiter *
task_top_pi_waiter(struct task_struct *p)
static inline struct rt_mutex_waiter *task_top_pi_waiter(struct task_struct *p)
{
return rb_entry(p->pi_waiters.rb_leftmost,
struct rt_mutex_waiter, pi_tree_entry);
return rb_entry(p->pi_waiters.rb_leftmost, struct rt_mutex_waiter,
pi_tree_entry);
}
#else
static inline int rt_mutex_has_waiters(struct rt_mutex *lock)
{
return false;
}
static inline struct rt_mutex_waiter *
rt_mutex_top_waiter(struct rt_mutex *lock)
{
return NULL;
}
static inline int task_has_pi_waiters(struct task_struct *p)
{
return false;
}
static inline struct rt_mutex_waiter *
task_top_pi_waiter(struct task_struct *p)
{
return NULL;
}
#endif
/*
* lock->owner state tracking:
*/
#define RT_MUTEX_HAS_WAITERS 1UL
static inline struct task_struct *rt_mutex_owner(struct rt_mutex *lock)
@@ -111,6 +78,13 @@ static inline struct task_struct *rt_mutex_owner(struct rt_mutex *lock)
return (struct task_struct *) (owner & ~RT_MUTEX_HAS_WAITERS);
}
#else /* CONFIG_RT_MUTEXES */
/* Used in rcu/tree_plugin.h */
static inline struct task_struct *rt_mutex_owner(struct rt_mutex *lock)
{
return NULL;
}
#endif /* !CONFIG_RT_MUTEXES */
/*
* Constants for rt mutex functions which have a selectable deadlock
@@ -127,10 +101,16 @@ enum rtmutex_chainwalk {
RT_MUTEX_FULL_CHAINWALK,
};
static inline void __rt_mutex_basic_init(struct rt_mutex *lock)
{
lock->owner = NULL;
raw_spin_lock_init(&lock->wait_lock);
lock->waiters = RB_ROOT_CACHED;
}
/*
* PI-futex support (proxy locking functions, etc.):
*/
extern struct task_struct *rt_mutex_next_owner(struct rt_mutex *lock);
extern void rt_mutex_init_proxy_locked(struct rt_mutex *lock,
struct task_struct *proxy_owner);
extern void rt_mutex_proxy_unlock(struct rt_mutex *lock);
@@ -156,10 +136,29 @@ extern bool __rt_mutex_futex_unlock(struct rt_mutex *lock,
extern void rt_mutex_postunlock(struct wake_q_head *wake_q);
#ifdef CONFIG_DEBUG_RT_MUTEXES
# include "rtmutex-debug.h"
#else
# include "rtmutex.h"
#endif
/* Debug functions */
static inline void debug_rt_mutex_unlock(struct rt_mutex *lock)
{
if (IS_ENABLED(CONFIG_DEBUG_RT_MUTEXES))
DEBUG_LOCKS_WARN_ON(rt_mutex_owner(lock) != current);
}
static inline void debug_rt_mutex_proxy_unlock(struct rt_mutex *lock)
{
if (IS_ENABLED(CONFIG_DEBUG_RT_MUTEXES))
DEBUG_LOCKS_WARN_ON(!rt_mutex_owner(lock));
}
static inline void debug_rt_mutex_init_waiter(struct rt_mutex_waiter *waiter)
{
if (IS_ENABLED(CONFIG_DEBUG_RT_MUTEXES))
memset(waiter, 0x11, sizeof(*waiter));
}
static inline void debug_rt_mutex_free_waiter(struct rt_mutex_waiter *waiter)
{
if (IS_ENABLED(CONFIG_DEBUG_RT_MUTEXES))
memset(waiter, 0x22, sizeof(*waiter));
}
#endif

4
kernel/locking/rwsem.c
View File

@@ -632,7 +632,7 @@ static inline bool rwsem_can_spin_on_owner(struct rw_semaphore *sem)
}
/*
* The rwsem_spin_on_owner() function returns the folowing 4 values
* The rwsem_spin_on_owner() function returns the following 4 values
* depending on the lock owner state.
* OWNER_NULL : owner is currently NULL
* OWNER_WRITER: when owner changes and is a writer
@@ -819,7 +819,7 @@ static bool rwsem_optimistic_spin(struct rw_semaphore *sem)
* we try to get it. The new owner may be a spinnable
* writer.
*
* To take advantage of two scenarios listed agove, the RT
* To take advantage of two scenarios listed above, the RT
* task is made to retry one more time to see if it can
* acquire the lock or continue spinning on the new owning
* writer. Of course, if the time lag is long enough or the

4
kernel/locking/spinlock.c
View File

@@ -58,10 +58,10 @@ EXPORT_PER_CPU_SYMBOL(__mmiowb_state);
/*
* We build the __lock_function inlines here. They are too large for
* inlining all over the place, but here is only one user per function
* which embedds them into the calling _lock_function below.
* which embeds them into the calling _lock_function below.
*
* This could be a long-held lock. We both prepare to spin for a long
* time (making _this_ CPU preemptable if possible), and we also signal
* time (making _this_ CPU preemptible if possible), and we also signal
* towards that other CPU that it should break the lock ASAP.
*/
#define BUILD_LOCK_OPS(op, locktype) \

18
kernel/sched/core.c
View File

@@ -5396,25 +5396,25 @@ static void sched_dynamic_update(int mode)
switch (mode) {
case preempt_dynamic_none:
static_call_update(cond_resched, __cond_resched);
static_call_update(might_resched, (typeof(&__cond_resched)) __static_call_return0);
static_call_update(preempt_schedule, (typeof(&preempt_schedule)) NULL);
static_call_update(preempt_schedule_notrace, (typeof(&preempt_schedule_notrace)) NULL);
static_call_update(irqentry_exit_cond_resched, (typeof(&irqentry_exit_cond_resched)) NULL);
static_call_update(might_resched, (void *)&__static_call_return0);
static_call_update(preempt_schedule, NULL);
static_call_update(preempt_schedule_notrace, NULL);
static_call_update(irqentry_exit_cond_resched, NULL);
pr_info("Dynamic Preempt: none\n");
break;
case preempt_dynamic_voluntary:
static_call_update(cond_resched, __cond_resched);
static_call_update(might_resched, __cond_resched);
static_call_update(preempt_schedule, (typeof(&preempt_schedule)) NULL);
static_call_update(preempt_schedule_notrace, (typeof(&preempt_schedule_notrace)) NULL);
static_call_update(irqentry_exit_cond_resched, (typeof(&irqentry_exit_cond_resched)) NULL);
static_call_update(preempt_schedule, NULL);
static_call_update(preempt_schedule_notrace, NULL);
static_call_update(irqentry_exit_cond_resched, NULL);
pr_info("Dynamic Preempt: voluntary\n");
break;
case preempt_dynamic_full:
static_call_update(cond_resched, (typeof(&__cond_resched)) __static_call_return0);
static_call_update(might_resched, (typeof(&__cond_resched)) __static_call_return0);
static_call_update(cond_resched, (void *)&__static_call_return0);
static_call_update(might_resched, (void *)&__static_call_return0);
static_call_update(preempt_schedule, __preempt_schedule_func);
static_call_update(preempt_schedule_notrace, __preempt_schedule_notrace_func);
static_call_update(irqentry_exit_cond_resched, irqentry_exit_cond_resched);

276
kernel/smp.c
View File

@@ -24,14 +24,70 @@
#include <linux/sched/clock.h>
#include <linux/nmi.h>
#include <linux/sched/debug.h>
#include <linux/jump_label.h>
#include "smpboot.h"
#include "sched/smp.h"
#define CSD_TYPE(_csd) ((_csd)->node.u_flags & CSD_FLAG_TYPE_MASK)
#ifdef CONFIG_CSD_LOCK_WAIT_DEBUG
union cfd_seq_cnt {
u64 val;
struct {
u64 src:16;
u64 dst:16;
#define CFD_SEQ_NOCPU 0xffff
u64 type:4;
#define CFD_SEQ_QUEUE 0
#define CFD_SEQ_IPI 1
#define CFD_SEQ_NOIPI 2
#define CFD_SEQ_PING 3
#define CFD_SEQ_PINGED 4
#define CFD_SEQ_HANDLE 5
#define CFD_SEQ_DEQUEUE 6
#define CFD_SEQ_IDLE 7
#define CFD_SEQ_GOTIPI 8
#define CFD_SEQ_HDLEND 9
u64 cnt:28;
} u;
};
static char *seq_type[] = {
[CFD_SEQ_QUEUE] = "queue",
[CFD_SEQ_IPI] = "ipi",
[CFD_SEQ_NOIPI] = "noipi",
[CFD_SEQ_PING] = "ping",
[CFD_SEQ_PINGED] = "pinged",
[CFD_SEQ_HANDLE] = "handle",
[CFD_SEQ_DEQUEUE] = "dequeue (src CPU 0 == empty)",
[CFD_SEQ_IDLE] = "idle",
[CFD_SEQ_GOTIPI] = "gotipi",
[CFD_SEQ_HDLEND] = "hdlend (src CPU 0 == early)",
};
struct cfd_seq_local {
u64 ping;
u64 pinged;
u64 handle;
u64 dequeue;
u64 idle;
u64 gotipi;
u64 hdlend;
};
#endif
struct cfd_percpu {
call_single_data_t csd;
#ifdef CONFIG_CSD_LOCK_WAIT_DEBUG
u64 seq_queue;
u64 seq_ipi;
u64 seq_noipi;
#endif
};
struct call_function_data {
call_single_data_t __percpu *csd;
struct cfd_percpu __percpu *pcpu;
cpumask_var_t cpumask;
cpumask_var_t cpumask_ipi;
};
@@ -54,8 +110,8 @@ int smpcfd_prepare_cpu(unsigned int cpu)
free_cpumask_var(cfd->cpumask);
return -ENOMEM;
}
cfd->csd = alloc_percpu(call_single_data_t);
if (!cfd->csd) {
cfd->pcpu = alloc_percpu(struct cfd_percpu);
if (!cfd->pcpu) {
free_cpumask_var(cfd->cpumask);
free_cpumask_var(cfd->cpumask_ipi);
return -ENOMEM;
@@ -70,7 +126,7 @@ int smpcfd_dead_cpu(unsigned int cpu)
free_cpumask_var(cfd->cpumask);
free_cpumask_var(cfd->cpumask_ipi);
free_percpu(cfd->csd);
free_percpu(cfd->pcpu);
return 0;
}
@@ -102,15 +158,60 @@ void __init call_function_init(void)
#ifdef CONFIG_CSD_LOCK_WAIT_DEBUG
static DEFINE_STATIC_KEY_FALSE(csdlock_debug_enabled);
static DEFINE_STATIC_KEY_FALSE(csdlock_debug_extended);
static int __init csdlock_debug(char *str)
{
unsigned int val = 0;
if (str && !strcmp(str, "ext")) {
val = 1;
static_branch_enable(&csdlock_debug_extended);
} else
get_option(&str, &val);
if (val)
static_branch_enable(&csdlock_debug_enabled);
return 0;
}
early_param("csdlock_debug", csdlock_debug);
static DEFINE_PER_CPU(call_single_data_t *, cur_csd);
static DEFINE_PER_CPU(smp_call_func_t, cur_csd_func);
static DEFINE_PER_CPU(void *, cur_csd_info);
static DEFINE_PER_CPU(struct cfd_seq_local, cfd_seq_local);
#define CSD_LOCK_TIMEOUT (5ULL * NSEC_PER_SEC)
static atomic_t csd_bug_count = ATOMIC_INIT(0);
static u64 cfd_seq;
#define CFD_SEQ(s, d, t, c) \
(union cfd_seq_cnt){ .u.src = s, .u.dst = d, .u.type = t, .u.cnt = c }
static u64 cfd_seq_inc(unsigned int src, unsigned int dst, unsigned int type)
{
union cfd_seq_cnt new, old;
new = CFD_SEQ(src, dst, type, 0);
do {
old.val = READ_ONCE(cfd_seq);
new.u.cnt = old.u.cnt + 1;
} while (cmpxchg(&cfd_seq, old.val, new.val) != old.val);
return old.val;
}
#define cfd_seq_store(var, src, dst, type) \
do { \
if (static_branch_unlikely(&csdlock_debug_extended)) \
var = cfd_seq_inc(src, dst, type); \
} while (0)
/* Record current CSD work for current CPU, NULL to erase. */
static void csd_lock_record(call_single_data_t *csd)
static void __csd_lock_record(call_single_data_t *csd)
{
if (!csd) {
smp_mb(); /* NULL cur_csd after unlock. */
@@ -125,7 +226,13 @@ static void csd_lock_record(call_single_data_t *csd)
/* Or before unlock, as the case may be. */
}
static __always_inline int csd_lock_wait_getcpu(call_single_data_t *csd)
static __always_inline void csd_lock_record(call_single_data_t *csd)
{
if (static_branch_unlikely(&csdlock_debug_enabled))
__csd_lock_record(csd);
}
static int csd_lock_wait_getcpu(call_single_data_t *csd)
{
unsigned int csd_type;
@@ -135,12 +242,86 @@ static __always_inline int csd_lock_wait_getcpu(call_single_data_t *csd)
return -1;
}
static void cfd_seq_data_add(u64 val, unsigned int src, unsigned int dst,
unsigned int type, union cfd_seq_cnt *data,
unsigned int *n_data, unsigned int now)
{
union cfd_seq_cnt new[2];
unsigned int i, j, k;
new[0].val = val;
new[1] = CFD_SEQ(src, dst, type, new[0].u.cnt + 1);
for (i = 0; i < 2; i++) {
if (new[i].u.cnt <= now)
new[i].u.cnt |= 0x80000000U;
for (j = 0; j < *n_data; j++) {
if (new[i].u.cnt == data[j].u.cnt) {
/* Direct read value trumps generated one. */
if (i == 0)
data[j].val = new[i].val;
break;
}
if (new[i].u.cnt < data[j].u.cnt) {
for (k = *n_data; k > j; k--)
data[k].val = data[k - 1].val;
data[j].val = new[i].val;
(*n_data)++;
break;
}
}
if (j == *n_data) {
data[j].val = new[i].val;
(*n_data)++;
}
}
}
static const char *csd_lock_get_type(unsigned int type)
{
return (type >= ARRAY_SIZE(seq_type)) ? "?" : seq_type[type];
}
static void csd_lock_print_extended(call_single_data_t *csd, int cpu)
{
struct cfd_seq_local *seq = &per_cpu(cfd_seq_local, cpu);
unsigned int srccpu = csd->node.src;
struct call_function_data *cfd = per_cpu_ptr(&cfd_data, srccpu);
struct cfd_percpu *pcpu = per_cpu_ptr(cfd->pcpu, cpu);
unsigned int now;
union cfd_seq_cnt data[2 * ARRAY_SIZE(seq_type)];
unsigned int n_data = 0, i;
data[0].val = READ_ONCE(cfd_seq);
now = data[0].u.cnt;
cfd_seq_data_add(pcpu->seq_queue, srccpu, cpu, CFD_SEQ_QUEUE, data, &n_data, now);
cfd_seq_data_add(pcpu->seq_ipi, srccpu, cpu, CFD_SEQ_IPI, data, &n_data, now);
cfd_seq_data_add(pcpu->seq_noipi, srccpu, cpu, CFD_SEQ_NOIPI, data, &n_data, now);
cfd_seq_data_add(per_cpu(cfd_seq_local.ping, srccpu), srccpu, CFD_SEQ_NOCPU, CFD_SEQ_PING, data, &n_data, now);
cfd_seq_data_add(per_cpu(cfd_seq_local.pinged, srccpu), srccpu, CFD_SEQ_NOCPU, CFD_SEQ_PINGED, data, &n_data, now);
cfd_seq_data_add(seq->idle, CFD_SEQ_NOCPU, cpu, CFD_SEQ_IDLE, data, &n_data, now);
cfd_seq_data_add(seq->gotipi, CFD_SEQ_NOCPU, cpu, CFD_SEQ_GOTIPI, data, &n_data, now);
cfd_seq_data_add(seq->handle, CFD_SEQ_NOCPU, cpu, CFD_SEQ_HANDLE, data, &n_data, now);
cfd_seq_data_add(seq->dequeue, CFD_SEQ_NOCPU, cpu, CFD_SEQ_DEQUEUE, data, &n_data, now);
cfd_seq_data_add(seq->hdlend, CFD_SEQ_NOCPU, cpu, CFD_SEQ_HDLEND, data, &n_data, now);
for (i = 0; i < n_data; i++) {
pr_alert("\tcsd: cnt(%07x): %04x->%04x %s\n",
data[i].u.cnt & ~0x80000000U, data[i].u.src,
data[i].u.dst, csd_lock_get_type(data[i].u.type));
}
pr_alert("\tcsd: cnt now: %07x\n", now);
}
/*
* Complain if too much time spent waiting. Note that only
* the CSD_TYPE_SYNC/ASYNC types provide the destination CPU,
* so waiting on other types gets much less information.
*/
static __always_inline bool csd_lock_wait_toolong(call_single_data_t *csd, u64 ts0, u64 *ts1, int *bug_id)
static bool csd_lock_wait_toolong(call_single_data_t *csd, u64 ts0, u64 *ts1, int *bug_id)
{
int cpu = -1;
int cpux;
@@ -184,6 +365,8 @@ static __always_inline bool csd_lock_wait_toolong(call_single_data_t *csd, u64 t
*bug_id, !cpu_cur_csd ? "unresponsive" : "handling this request");
}
if (cpu >= 0) {
if (static_branch_unlikely(&csdlock_debug_extended))
csd_lock_print_extended(csd, cpu);
if (!trigger_single_cpu_backtrace(cpu))
dump_cpu_task(cpu);
if (!cpu_cur_csd) {
@@ -204,7 +387,7 @@ static __always_inline bool csd_lock_wait_toolong(call_single_data_t *csd, u64 t
* previous function call. For multi-cpu calls its even more interesting
* as we'll have to ensure no other cpu is observing our csd.
*/
static __always_inline void csd_lock_wait(call_single_data_t *csd)
static void __csd_lock_wait(call_single_data_t *csd)
{
int bug_id = 0;
u64 ts0, ts1;
@@ -218,7 +401,36 @@ static __always_inline void csd_lock_wait(call_single_data_t *csd)
smp_acquire__after_ctrl_dep();
}
static __always_inline void csd_lock_wait(call_single_data_t *csd)
{
if (static_branch_unlikely(&csdlock_debug_enabled)) {
__csd_lock_wait(csd);
return;
}
smp_cond_load_acquire(&csd->node.u_flags, !(VAL & CSD_FLAG_LOCK));
}
static void __smp_call_single_queue_debug(int cpu, struct llist_node *node)
{
unsigned int this_cpu = smp_processor_id();
struct cfd_seq_local *seq = this_cpu_ptr(&cfd_seq_local);
struct call_function_data *cfd = this_cpu_ptr(&cfd_data);
struct cfd_percpu *pcpu = per_cpu_ptr(cfd->pcpu, cpu);
cfd_seq_store(pcpu->seq_queue, this_cpu, cpu, CFD_SEQ_QUEUE);
if (llist_add(node, &per_cpu(call_single_queue, cpu))) {
cfd_seq_store(pcpu->seq_ipi, this_cpu, cpu, CFD_SEQ_IPI);
cfd_seq_store(seq->ping, this_cpu, cpu, CFD_SEQ_PING);
send_call_function_single_ipi(cpu);
cfd_seq_store(seq->pinged, this_cpu, cpu, CFD_SEQ_PINGED);
} else {
cfd_seq_store(pcpu->seq_noipi, this_cpu, cpu, CFD_SEQ_NOIPI);
}
}
#else
#define cfd_seq_store(var, src, dst, type)
static void csd_lock_record(call_single_data_t *csd)
{
}
@@ -256,6 +468,19 @@ static DEFINE_PER_CPU_SHARED_ALIGNED(call_single_data_t, csd_data);
void __smp_call_single_queue(int cpu, struct llist_node *node)
{
#ifdef CONFIG_CSD_LOCK_WAIT_DEBUG
if (static_branch_unlikely(&csdlock_debug_extended)) {
unsigned int type;
type = CSD_TYPE(container_of(node, call_single_data_t,
node.llist));
if (type == CSD_TYPE_SYNC || type == CSD_TYPE_ASYNC) {
__smp_call_single_queue_debug(cpu, node);
return;
}
}
#endif
/*
* The list addition should be visible before sending the IPI
* handler locks the list to pull the entry off it because of
@@ -314,6 +539,8 @@ static int generic_exec_single(int cpu, call_single_data_t *csd)
*/
void generic_smp_call_function_single_interrupt(void)
{
cfd_seq_store(this_cpu_ptr(&cfd_seq_local)->gotipi, CFD_SEQ_NOCPU,
smp_processor_id(), CFD_SEQ_GOTIPI);
flush_smp_call_function_queue(true);
}
@@ -341,7 +568,13 @@ static void flush_smp_call_function_queue(bool warn_cpu_offline)
lockdep_assert_irqs_disabled();
head = this_cpu_ptr(&call_single_queue);
cfd_seq_store(this_cpu_ptr(&cfd_seq_local)->handle, CFD_SEQ_NOCPU,
smp_processor_id(), CFD_SEQ_HANDLE);
entry = llist_del_all(head);
cfd_seq_store(this_cpu_ptr(&cfd_seq_local)->dequeue,
/* Special meaning of source cpu: 0 == queue empty */
entry ? CFD_SEQ_NOCPU : 0,
smp_processor_id(), CFD_SEQ_DEQUEUE);
entry = llist_reverse_order(entry);
/* There shouldn't be any pending callbacks on an offline CPU. */
@@ -400,8 +633,12 @@ static void flush_smp_call_function_queue(bool warn_cpu_offline)
}
}
if (!entry)
if (!entry) {
cfd_seq_store(this_cpu_ptr(&cfd_seq_local)->hdlend,
0, smp_processor_id(),
CFD_SEQ_HDLEND);
return;
}
/*
* Second; run all !SYNC callbacks.
@@ -439,6 +676,9 @@ static void flush_smp_call_function_queue(bool warn_cpu_offline)
*/
if (entry)
sched_ttwu_pending(entry);
cfd_seq_store(this_cpu_ptr(&cfd_seq_local)->hdlend, CFD_SEQ_NOCPU,
smp_processor_id(), CFD_SEQ_HDLEND);
}
void flush_smp_call_function_from_idle(void)
@@ -448,6 +688,8 @@ void flush_smp_call_function_from_idle(void)
if (llist_empty(this_cpu_ptr(&call_single_queue)))
return;
cfd_seq_store(this_cpu_ptr(&cfd_seq_local)->idle, CFD_SEQ_NOCPU,
smp_processor_id(), CFD_SEQ_IDLE);
local_irq_save(flags);
flush_smp_call_function_queue(true);
if (local_softirq_pending())
@@ -664,7 +906,8 @@ static void smp_call_function_many_cond(const struct cpumask *mask,
cpumask_clear(cfd->cpumask_ipi);
for_each_cpu(cpu, cfd->cpumask) {
call_single_data_t *csd = per_cpu_ptr(cfd->csd, cpu);
struct cfd_percpu *pcpu = per_cpu_ptr(cfd->pcpu, cpu);
call_single_data_t *csd = &pcpu->csd;
if (cond_func && !cond_func(cpu, info))
continue;
@@ -678,18 +921,27 @@ static void smp_call_function_many_cond(const struct cpumask *mask,
csd->node.src = smp_processor_id();
csd->node.dst = cpu;
#endif
if (llist_add(&csd->node.llist, &per_cpu(call_single_queue, cpu)))
cfd_seq_store(pcpu->seq_queue, this_cpu, cpu, CFD_SEQ_QUEUE);
if (llist_add(&csd->node.llist, &per_cpu(call_single_queue, cpu))) {
__cpumask_set_cpu(cpu, cfd->cpumask_ipi);
cfd_seq_store(pcpu->seq_ipi, this_cpu, cpu, CFD_SEQ_IPI);
} else {
cfd_seq_store(pcpu->seq_noipi, this_cpu, cpu, CFD_SEQ_NOIPI);
}
}
/* Send a message to all CPUs in the map */
cfd_seq_store(this_cpu_ptr(&cfd_seq_local)->ping, this_cpu,
CFD_SEQ_NOCPU, CFD_SEQ_PING);
arch_send_call_function_ipi_mask(cfd->cpumask_ipi);
cfd_seq_store(this_cpu_ptr(&cfd_seq_local)->pinged, this_cpu,
CFD_SEQ_NOCPU, CFD_SEQ_PINGED);
if (wait) {
for_each_cpu(cpu, cfd->cpumask) {
call_single_data_t *csd;
csd = per_cpu_ptr(cfd->csd, cpu);
csd = &per_cpu_ptr(cfd->pcpu, cpu)->csd;
csd_lock_wait(csd);
}
}

4
kernel/static_call.c
View File

@@ -165,13 +165,13 @@ void __static_call_update(struct static_call_key *key, void *tramp, void *func)
stop = __stop_static_call_sites;
#ifdef CONFIG_MODULES
if (mod) {
#ifdef CONFIG_MODULES
stop = mod->static_call_sites +
mod->num_static_call_sites;
init = mod->state == MODULE_STATE_COMING;
}
#endif
}
for (site = site_mod->sites;
site < stop && static_call_key(site) == key; site++) {