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-rw-r--r--arch/x86/include/asm/alternative.h2
-rw-r--r--arch/x86/include/asm/barrier.h8
-rw-r--r--arch/x86/include/asm/cmpxchg.h4
-rw-r--r--arch/x86/include/asm/cmpxchg_32.h36
-rw-r--r--arch/x86/include/asm/edac.h2
-rw-r--r--arch/x86/include/asm/percpu.h77
-rw-r--r--arch/x86/include/asm/sync_bitops.h12
-rw-r--r--arch/x86/kernel/cpu/bus_lock.c20
-rw-r--r--include/linux/interrupt.h16
-rw-r--r--kernel/locking/Makefile3
-rw-r--r--kernel/locking/lock_events_list.h28
-rw-r--r--kernel/locking/lockdep.c17
-rw-r--r--kernel/locking/mutex.c2
-rw-r--r--kernel/locking/rtmutex.c29
-rw-r--r--mm/memory.c2
-rw-r--r--rust/helpers/helpers.c1
-rw-r--r--rust/helpers/sync.c13
-rw-r--r--rust/kernel/sync.rs57
-rw-r--r--rust/kernel/sync/condvar.rs28
-rw-r--r--rust/kernel/sync/lock.rs35
-rw-r--r--rust/kernel/sync/lock/global.rs5
-rw-r--r--rust/kernel/sync/poll.rs2
-rw-r--r--rust/kernel/task.rs2
-rw-r--r--rust/kernel/workqueue.rs2
24 files changed, 294 insertions, 109 deletions
diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
index e3903b731305..3b3d3aa19acd 100644
--- a/arch/x86/include/asm/alternative.h
+++ b/arch/x86/include/asm/alternative.h
@@ -48,7 +48,7 @@
".popsection\n" \
"671:"
-#define LOCK_PREFIX LOCK_PREFIX_HERE "\n\tlock; "
+#define LOCK_PREFIX LOCK_PREFIX_HERE "\n\tlock "
#else /* ! CONFIG_SMP */
#define LOCK_PREFIX_HERE ""
diff --git a/arch/x86/include/asm/barrier.h b/arch/x86/include/asm/barrier.h
index 7b44b3c4cce1..db70832232d4 100644
--- a/arch/x86/include/asm/barrier.h
+++ b/arch/x86/include/asm/barrier.h
@@ -12,11 +12,11 @@
*/
#ifdef CONFIG_X86_32
-#define mb() asm volatile(ALTERNATIVE("lock; addl $0,-4(%%esp)", "mfence", \
+#define mb() asm volatile(ALTERNATIVE("lock addl $0,-4(%%esp)", "mfence", \
X86_FEATURE_XMM2) ::: "memory", "cc")
-#define rmb() asm volatile(ALTERNATIVE("lock; addl $0,-4(%%esp)", "lfence", \
+#define rmb() asm volatile(ALTERNATIVE("lock addl $0,-4(%%esp)", "lfence", \
X86_FEATURE_XMM2) ::: "memory", "cc")
-#define wmb() asm volatile(ALTERNATIVE("lock; addl $0,-4(%%esp)", "sfence", \
+#define wmb() asm volatile(ALTERNATIVE("lock addl $0,-4(%%esp)", "sfence", \
X86_FEATURE_XMM2) ::: "memory", "cc")
#else
#define __mb() asm volatile("mfence":::"memory")
@@ -50,7 +50,7 @@
#define __dma_rmb() barrier()
#define __dma_wmb() barrier()
-#define __smp_mb() asm volatile("lock; addl $0,-4(%%" _ASM_SP ")" ::: "memory", "cc")
+#define __smp_mb() asm volatile("lock addl $0,-4(%%" _ASM_SP ")" ::: "memory", "cc")
#define __smp_rmb() dma_rmb()
#define __smp_wmb() barrier()
diff --git a/arch/x86/include/asm/cmpxchg.h b/arch/x86/include/asm/cmpxchg.h
index 5612648b0202..fd8afc1f5f6b 100644
--- a/arch/x86/include/asm/cmpxchg.h
+++ b/arch/x86/include/asm/cmpxchg.h
@@ -134,7 +134,7 @@ extern void __add_wrong_size(void)
__raw_cmpxchg((ptr), (old), (new), (size), LOCK_PREFIX)
#define __sync_cmpxchg(ptr, old, new, size) \
- __raw_cmpxchg((ptr), (old), (new), (size), "lock; ")
+ __raw_cmpxchg((ptr), (old), (new), (size), "lock ")
#define __cmpxchg_local(ptr, old, new, size) \
__raw_cmpxchg((ptr), (old), (new), (size), "")
@@ -222,7 +222,7 @@ extern void __add_wrong_size(void)
__raw_try_cmpxchg((ptr), (pold), (new), (size), LOCK_PREFIX)
#define __sync_try_cmpxchg(ptr, pold, new, size) \
- __raw_try_cmpxchg((ptr), (pold), (new), (size), "lock; ")
+ __raw_try_cmpxchg((ptr), (pold), (new), (size), "lock ")
#define __try_cmpxchg_local(ptr, pold, new, size) \
__raw_try_cmpxchg((ptr), (pold), (new), (size), "")
diff --git a/arch/x86/include/asm/cmpxchg_32.h b/arch/x86/include/asm/cmpxchg_32.h
index fd1282a783dd..8806c646d452 100644
--- a/arch/x86/include/asm/cmpxchg_32.h
+++ b/arch/x86/include/asm/cmpxchg_32.h
@@ -91,19 +91,21 @@ static __always_inline bool __try_cmpxchg64_local(volatile u64 *ptr, u64 *oldp,
union __u64_halves o = { .full = (_old), }, \
n = { .full = (_new), }; \
\
- asm volatile(ALTERNATIVE(_lock_loc \
- "call cmpxchg8b_emu", \
- _lock "cmpxchg8b %a[ptr]", X86_FEATURE_CX8) \
- : ALT_OUTPUT_SP("+a" (o.low), "+d" (o.high)) \
- : "b" (n.low), "c" (n.high), [ptr] "S" (_ptr) \
- : "memory"); \
+ asm_inline volatile( \
+ ALTERNATIVE(_lock_loc \
+ "call cmpxchg8b_emu", \
+ _lock "cmpxchg8b %a[ptr]", X86_FEATURE_CX8) \
+ : ALT_OUTPUT_SP("+a" (o.low), "+d" (o.high)) \
+ : "b" (n.low), "c" (n.high), \
+ [ptr] "S" (_ptr) \
+ : "memory"); \
\
o.full; \
})
static __always_inline u64 arch_cmpxchg64(volatile u64 *ptr, u64 old, u64 new)
{
- return __arch_cmpxchg64_emu(ptr, old, new, LOCK_PREFIX_HERE, "lock; ");
+ return __arch_cmpxchg64_emu(ptr, old, new, LOCK_PREFIX_HERE, "lock ");
}
#define arch_cmpxchg64 arch_cmpxchg64
@@ -119,14 +121,16 @@ static __always_inline u64 arch_cmpxchg64_local(volatile u64 *ptr, u64 old, u64
n = { .full = (_new), }; \
bool ret; \
\
- asm volatile(ALTERNATIVE(_lock_loc \
- "call cmpxchg8b_emu", \
- _lock "cmpxchg8b %a[ptr]", X86_FEATURE_CX8) \
- CC_SET(e) \
- : ALT_OUTPUT_SP(CC_OUT(e) (ret), \
- "+a" (o.low), "+d" (o.high)) \
- : "b" (n.low), "c" (n.high), [ptr] "S" (_ptr) \
- : "memory"); \
+ asm_inline volatile( \
+ ALTERNATIVE(_lock_loc \
+ "call cmpxchg8b_emu", \
+ _lock "cmpxchg8b %a[ptr]", X86_FEATURE_CX8) \
+ CC_SET(e) \
+ : ALT_OUTPUT_SP(CC_OUT(e) (ret), \
+ "+a" (o.low), "+d" (o.high)) \
+ : "b" (n.low), "c" (n.high), \
+ [ptr] "S" (_ptr) \
+ : "memory"); \
\
if (unlikely(!ret)) \
*(_oldp) = o.full; \
@@ -136,7 +140,7 @@ static __always_inline u64 arch_cmpxchg64_local(volatile u64 *ptr, u64 old, u64
static __always_inline bool arch_try_cmpxchg64(volatile u64 *ptr, u64 *oldp, u64 new)
{
- return __arch_try_cmpxchg64_emu(ptr, oldp, new, LOCK_PREFIX_HERE, "lock; ");
+ return __arch_try_cmpxchg64_emu(ptr, oldp, new, LOCK_PREFIX_HERE, "lock ");
}
#define arch_try_cmpxchg64 arch_try_cmpxchg64
diff --git a/arch/x86/include/asm/edac.h b/arch/x86/include/asm/edac.h
index 426fc53ff803..dfbd1ebb9f10 100644
--- a/arch/x86/include/asm/edac.h
+++ b/arch/x86/include/asm/edac.h
@@ -13,7 +13,7 @@ static inline void edac_atomic_scrub(void *va, u32 size)
* are interrupt, DMA and SMP safe.
*/
for (i = 0; i < size / 4; i++, virt_addr++)
- asm volatile("lock; addl $0, %0"::"m" (*virt_addr));
+ asm volatile("lock addl $0, %0"::"m" (*virt_addr));
}
#endif /* _ASM_X86_EDAC_H */
diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h
index e525cd85f999..08f5f61690b7 100644
--- a/arch/x86/include/asm/percpu.h
+++ b/arch/x86/include/asm/percpu.h
@@ -348,15 +348,14 @@ do { \
old__.var = _oval; \
new__.var = _nval; \
\
- asm qual (ALTERNATIVE("call this_cpu_cmpxchg8b_emu", \
- "cmpxchg8b " __percpu_arg([var]), X86_FEATURE_CX8) \
- : [var] "+m" (__my_cpu_var(_var)), \
- "+a" (old__.low), \
- "+d" (old__.high) \
- : "b" (new__.low), \
- "c" (new__.high), \
- "S" (&(_var)) \
- : "memory"); \
+ asm_inline qual ( \
+ ALTERNATIVE("call this_cpu_cmpxchg8b_emu", \
+ "cmpxchg8b " __percpu_arg([var]), X86_FEATURE_CX8) \
+ : ALT_OUTPUT_SP([var] "+m" (__my_cpu_var(_var)), \
+ "+a" (old__.low), "+d" (old__.high)) \
+ : "b" (new__.low), "c" (new__.high), \
+ "S" (&(_var)) \
+ : "memory"); \
\
old__.var; \
})
@@ -378,17 +377,16 @@ do { \
old__.var = *_oval; \
new__.var = _nval; \
\
- asm qual (ALTERNATIVE("call this_cpu_cmpxchg8b_emu", \
- "cmpxchg8b " __percpu_arg([var]), X86_FEATURE_CX8) \
- CC_SET(z) \
- : CC_OUT(z) (success), \
- [var] "+m" (__my_cpu_var(_var)), \
- "+a" (old__.low), \
- "+d" (old__.high) \
- : "b" (new__.low), \
- "c" (new__.high), \
- "S" (&(_var)) \
- : "memory"); \
+ asm_inline qual ( \
+ ALTERNATIVE("call this_cpu_cmpxchg8b_emu", \
+ "cmpxchg8b " __percpu_arg([var]), X86_FEATURE_CX8) \
+ CC_SET(z) \
+ : ALT_OUTPUT_SP(CC_OUT(z) (success), \
+ [var] "+m" (__my_cpu_var(_var)), \
+ "+a" (old__.low), "+d" (old__.high)) \
+ : "b" (new__.low), "c" (new__.high), \
+ "S" (&(_var)) \
+ : "memory"); \
if (unlikely(!success)) \
*_oval = old__.var; \
\
@@ -419,15 +417,14 @@ do { \
old__.var = _oval; \
new__.var = _nval; \
\
- asm qual (ALTERNATIVE("call this_cpu_cmpxchg16b_emu", \
- "cmpxchg16b " __percpu_arg([var]), X86_FEATURE_CX16) \
- : [var] "+m" (__my_cpu_var(_var)), \
- "+a" (old__.low), \
- "+d" (old__.high) \
- : "b" (new__.low), \
- "c" (new__.high), \
- "S" (&(_var)) \
- : "memory"); \
+ asm_inline qual ( \
+ ALTERNATIVE("call this_cpu_cmpxchg16b_emu", \
+ "cmpxchg16b " __percpu_arg([var]), X86_FEATURE_CX16) \
+ : ALT_OUTPUT_SP([var] "+m" (__my_cpu_var(_var)), \
+ "+a" (old__.low), "+d" (old__.high)) \
+ : "b" (new__.low), "c" (new__.high), \
+ "S" (&(_var)) \
+ : "memory"); \
\
old__.var; \
})
@@ -449,19 +446,19 @@ do { \
old__.var = *_oval; \
new__.var = _nval; \
\
- asm qual (ALTERNATIVE("call this_cpu_cmpxchg16b_emu", \
- "cmpxchg16b " __percpu_arg([var]), X86_FEATURE_CX16) \
- CC_SET(z) \
- : CC_OUT(z) (success), \
- [var] "+m" (__my_cpu_var(_var)), \
- "+a" (old__.low), \
- "+d" (old__.high) \
- : "b" (new__.low), \
- "c" (new__.high), \
- "S" (&(_var)) \
- : "memory"); \
+ asm_inline qual ( \
+ ALTERNATIVE("call this_cpu_cmpxchg16b_emu", \
+ "cmpxchg16b " __percpu_arg([var]), X86_FEATURE_CX16) \
+ CC_SET(z) \
+ : ALT_OUTPUT_SP(CC_OUT(z) (success), \
+ [var] "+m" (__my_cpu_var(_var)), \
+ "+a" (old__.low), "+d" (old__.high)) \
+ : "b" (new__.low), "c" (new__.high), \
+ "S" (&(_var)) \
+ : "memory"); \
if (unlikely(!success)) \
*_oval = old__.var; \
+ \
likely(success); \
})
diff --git a/arch/x86/include/asm/sync_bitops.h b/arch/x86/include/asm/sync_bitops.h
index 6d8d6bc183b7..cd21a0405ac5 100644
--- a/arch/x86/include/asm/sync_bitops.h
+++ b/arch/x86/include/asm/sync_bitops.h
@@ -31,7 +31,7 @@
*/
static inline void sync_set_bit(long nr, volatile unsigned long *addr)
{
- asm volatile("lock; " __ASM_SIZE(bts) " %1,%0"
+ asm volatile("lock " __ASM_SIZE(bts) " %1,%0"
: "+m" (ADDR)
: "Ir" (nr)
: "memory");
@@ -49,7 +49,7 @@ static inline void sync_set_bit(long nr, volatile unsigned long *addr)
*/
static inline void sync_clear_bit(long nr, volatile unsigned long *addr)
{
- asm volatile("lock; " __ASM_SIZE(btr) " %1,%0"
+ asm volatile("lock " __ASM_SIZE(btr) " %1,%0"
: "+m" (ADDR)
: "Ir" (nr)
: "memory");
@@ -66,7 +66,7 @@ static inline void sync_clear_bit(long nr, volatile unsigned long *addr)
*/
static inline void sync_change_bit(long nr, volatile unsigned long *addr)
{
- asm volatile("lock; " __ASM_SIZE(btc) " %1,%0"
+ asm volatile("lock " __ASM_SIZE(btc) " %1,%0"
: "+m" (ADDR)
: "Ir" (nr)
: "memory");
@@ -82,7 +82,7 @@ static inline void sync_change_bit(long nr, volatile unsigned long *addr)
*/
static inline bool sync_test_and_set_bit(long nr, volatile unsigned long *addr)
{
- return GEN_BINARY_RMWcc("lock; " __ASM_SIZE(bts), *addr, c, "Ir", nr);
+ return GEN_BINARY_RMWcc("lock " __ASM_SIZE(bts), *addr, c, "Ir", nr);
}
/**
@@ -95,7 +95,7 @@ static inline bool sync_test_and_set_bit(long nr, volatile unsigned long *addr)
*/
static inline int sync_test_and_clear_bit(long nr, volatile unsigned long *addr)
{
- return GEN_BINARY_RMWcc("lock; " __ASM_SIZE(btr), *addr, c, "Ir", nr);
+ return GEN_BINARY_RMWcc("lock " __ASM_SIZE(btr), *addr, c, "Ir", nr);
}
/**
@@ -108,7 +108,7 @@ static inline int sync_test_and_clear_bit(long nr, volatile unsigned long *addr)
*/
static inline int sync_test_and_change_bit(long nr, volatile unsigned long *addr)
{
- return GEN_BINARY_RMWcc("lock; " __ASM_SIZE(btc), *addr, c, "Ir", nr);
+ return GEN_BINARY_RMWcc("lock " __ASM_SIZE(btc), *addr, c, "Ir", nr);
}
#define sync_test_bit(nr, addr) test_bit(nr, addr)
diff --git a/arch/x86/kernel/cpu/bus_lock.c b/arch/x86/kernel/cpu/bus_lock.c
index 6cba85c79d42..97222efb4d2a 100644
--- a/arch/x86/kernel/cpu/bus_lock.c
+++ b/arch/x86/kernel/cpu/bus_lock.c
@@ -192,7 +192,13 @@ static void __split_lock_reenable(struct work_struct *work)
{
sld_update_msr(true);
}
-static DECLARE_DELAYED_WORK(sl_reenable, __split_lock_reenable);
+/*
+ * In order for each CPU to schedule its delayed work independently of the
+ * others, delayed work struct must be per-CPU. This is not required when
+ * sysctl_sld_mitigate is enabled because of the semaphore that limits
+ * the number of simultaneously scheduled delayed works to 1.
+ */
+static DEFINE_PER_CPU(struct delayed_work, sl_reenable);
/*
* If a CPU goes offline with pending delayed work to re-enable split lock
@@ -213,7 +219,7 @@ static int splitlock_cpu_offline(unsigned int cpu)
static void split_lock_warn(unsigned long ip)
{
- struct delayed_work *work;
+ struct delayed_work *work = NULL;
int cpu;
if (!current->reported_split_lock)
@@ -235,11 +241,17 @@ static void split_lock_warn(unsigned long ip)
if (down_interruptible(&buslock_sem) == -EINTR)
return;
work = &sl_reenable_unlock;
- } else {
- work = &sl_reenable;
}
cpu = get_cpu();
+
+ if (!work) {
+ work = this_cpu_ptr(&sl_reenable);
+ /* Deferred initialization of per-CPU struct */
+ if (!work->work.func)
+ INIT_DELAYED_WORK(work, __split_lock_reenable);
+ }
+
schedule_delayed_work_on(cpu, work, 2);
/* Disable split lock detection on this CPU to make progress */
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 8cd9327e4e78..c782a74d2a30 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -448,7 +448,7 @@ irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
static inline void disable_irq_nosync_lockdep(unsigned int irq)
{
disable_irq_nosync(irq);
-#ifdef CONFIG_LOCKDEP
+#if defined(CONFIG_LOCKDEP) && !defined(CONFIG_PREEMPT_RT)
local_irq_disable();
#endif
}
@@ -456,22 +456,14 @@ static inline void disable_irq_nosync_lockdep(unsigned int irq)
static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
{
disable_irq_nosync(irq);
-#ifdef CONFIG_LOCKDEP
+#if defined(CONFIG_LOCKDEP) && !defined(CONFIG_PREEMPT_RT)
local_irq_save(*flags);
#endif
}
-static inline void disable_irq_lockdep(unsigned int irq)
-{
- disable_irq(irq);
-#ifdef CONFIG_LOCKDEP
- local_irq_disable();
-#endif
-}
-
static inline void enable_irq_lockdep(unsigned int irq)
{
-#ifdef CONFIG_LOCKDEP
+#if defined(CONFIG_LOCKDEP) && !defined(CONFIG_PREEMPT_RT)
local_irq_enable();
#endif
enable_irq(irq);
@@ -479,7 +471,7 @@ static inline void enable_irq_lockdep(unsigned int irq)
static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
{
-#ifdef CONFIG_LOCKDEP
+#if defined(CONFIG_LOCKDEP) && !defined(CONFIG_PREEMPT_RT)
local_irq_restore(*flags);
#endif
enable_irq(irq);
diff --git a/kernel/locking/Makefile b/kernel/locking/Makefile
index 0db4093d17b8..a114949eeed5 100644
--- a/kernel/locking/Makefile
+++ b/kernel/locking/Makefile
@@ -5,7 +5,8 @@ KCOV_INSTRUMENT := n
obj-y += mutex.o semaphore.o rwsem.o percpu-rwsem.o
-# Avoid recursion lockdep -> sanitizer -> ... -> lockdep.
+# Avoid recursion lockdep -> sanitizer -> ... -> lockdep & improve performance.
+KASAN_SANITIZE_lockdep.o := n
KCSAN_SANITIZE_lockdep.o := n
ifdef CONFIG_FUNCTION_TRACER
diff --git a/kernel/locking/lock_events_list.h b/kernel/locking/lock_events_list.h
index 97fb6f3f840a..9ef9850aeebe 100644
--- a/kernel/locking/lock_events_list.h
+++ b/kernel/locking/lock_events_list.h
@@ -67,3 +67,31 @@ LOCK_EVENT(rwsem_rlock_handoff) /* # of read lock handoffs */
LOCK_EVENT(rwsem_wlock) /* # of write locks acquired */
LOCK_EVENT(rwsem_wlock_fail) /* # of failed write lock acquisitions */
LOCK_EVENT(rwsem_wlock_handoff) /* # of write lock handoffs */
+
+/*
+ * Locking events for rtlock_slowlock()
+ */
+LOCK_EVENT(rtlock_slowlock) /* # of rtlock_slowlock() calls */
+LOCK_EVENT(rtlock_slow_acq1) /* # of locks acquired after wait_lock */
+LOCK_EVENT(rtlock_slow_acq2) /* # of locks acquired in for loop */
+LOCK_EVENT(rtlock_slow_sleep) /* # of sleeps */
+LOCK_EVENT(rtlock_slow_wake) /* # of wakeup's */
+
+/*
+ * Locking events for rt_mutex_slowlock()
+ */
+LOCK_EVENT(rtmutex_slowlock) /* # of rt_mutex_slowlock() calls */
+LOCK_EVENT(rtmutex_slow_block) /* # of rt_mutex_slowlock_block() calls */
+LOCK_EVENT(rtmutex_slow_acq1) /* # of locks acquired after wait_lock */
+LOCK_EVENT(rtmutex_slow_acq2) /* # of locks acquired at the end */
+LOCK_EVENT(rtmutex_slow_acq3) /* # of locks acquired in *block() */
+LOCK_EVENT(rtmutex_slow_sleep) /* # of sleeps */
+LOCK_EVENT(rtmutex_slow_wake) /* # of wakeup's */
+LOCK_EVENT(rtmutex_deadlock) /* # of rt_mutex_handle_deadlock()'s */
+
+/*
+ * Locking events for lockdep
+ */
+LOCK_EVENT(lockdep_acquire)
+LOCK_EVENT(lockdep_lock)
+LOCK_EVENT(lockdep_nocheck)
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 4470680f0226..b15757e63626 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -57,10 +57,12 @@
#include <linux/lockdep.h>
#include <linux/context_tracking.h>
#include <linux/console.h>
+#include <linux/kasan.h>
#include <asm/sections.h>
#include "lockdep_internals.h"
+#include "lock_events.h"
#include <trace/events/lock.h>
@@ -170,6 +172,7 @@ static struct task_struct *lockdep_selftest_task_struct;
static int graph_lock(void)
{
lockdep_lock();
+ lockevent_inc(lockdep_lock);
/*
* Make sure that if another CPU detected a bug while
* walking the graph we dont change it (while the other
@@ -5091,8 +5094,12 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
if (unlikely(lock->key == &__lockdep_no_track__))
return 0;
- if (!prove_locking || lock->key == &__lockdep_no_validate__)
+ lockevent_inc(lockdep_acquire);
+
+ if (!prove_locking || lock->key == &__lockdep_no_validate__) {
check = 0;
+ lockevent_inc(lockdep_nocheck);
+ }
if (subclass < NR_LOCKDEP_CACHING_CLASSES)
class = lock->class_cache[subclass];
@@ -5824,6 +5831,14 @@ void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
if (!debug_locks)
return;
+ /*
+ * As KASAN instrumentation is disabled and lock_acquire() is usually
+ * the first lockdep call when a task tries to acquire a lock, add
+ * kasan_check_byte() here to check for use-after-free and other
+ * memory errors.
+ */
+ kasan_check_byte(lock);
+
if (unlikely(!lockdep_enabled())) {
/* XXX allow trylock from NMI ?!? */
if (lockdep_nmi() && !trylock) {
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index b36f23de48f1..19b636f60a24 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -143,6 +143,8 @@ static __always_inline bool __mutex_trylock_fast(struct mutex *lock)
unsigned long curr = (unsigned long)current;
unsigned long zero = 0UL;
+ MUTEX_WARN_ON(lock->magic != lock);
+
if (atomic_long_try_cmpxchg_acquire(&lock->owner, &zero, curr))
return true;
diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index 4a8df1800cbb..c80902eacd79 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -27,6 +27,7 @@
#include <trace/events/lock.h>
#include "rtmutex_common.h"
+#include "lock_events.h"
#ifndef WW_RT
# define build_ww_mutex() (false)
@@ -1612,10 +1613,13 @@ static int __sched rt_mutex_slowlock_block(struct rt_mutex_base *lock,
struct task_struct *owner;
int ret = 0;
+ lockevent_inc(rtmutex_slow_block);
for (;;) {
/* Try to acquire the lock: */
- if (try_to_take_rt_mutex(lock, current, waiter))
+ if (try_to_take_rt_mutex(lock, current, waiter)) {
+ lockevent_inc(rtmutex_slow_acq3);
break;
+ }
if (timeout && !timeout->task) {
ret = -ETIMEDOUT;
@@ -1638,8 +1642,10 @@ static int __sched rt_mutex_slowlock_block(struct rt_mutex_base *lock,
owner = NULL;
raw_spin_unlock_irq_wake(&lock->wait_lock, wake_q);
- if (!owner || !rtmutex_spin_on_owner(lock, waiter, owner))
+ if (!owner || !rtmutex_spin_on_owner(lock, waiter, owner)) {
+ lockevent_inc(rtmutex_slow_sleep);
rt_mutex_schedule();
+ }
raw_spin_lock_irq(&lock->wait_lock);
set_current_state(state);
@@ -1694,6 +1700,7 @@ static int __sched __rt_mutex_slowlock(struct rt_mutex_base *lock,
int ret;
lockdep_assert_held(&lock->wait_lock);
+ lockevent_inc(rtmutex_slowlock);
/* Try to acquire the lock again: */
if (try_to_take_rt_mutex(lock, current, NULL)) {
@@ -1701,6 +1708,7 @@ static int __sched __rt_mutex_slowlock(struct rt_mutex_base *lock,
__ww_mutex_check_waiters(rtm, ww_ctx, wake_q);
ww_mutex_lock_acquired(ww, ww_ctx);
}
+ lockevent_inc(rtmutex_slow_acq1);
return 0;
}
@@ -1719,10 +1727,12 @@ static int __sched __rt_mutex_slowlock(struct rt_mutex_base *lock,
__ww_mutex_check_waiters(rtm, ww_ctx, wake_q);
ww_mutex_lock_acquired(ww, ww_ctx);
}
+ lockevent_inc(rtmutex_slow_acq2);
} else {
__set_current_state(TASK_RUNNING);
remove_waiter(lock, waiter);
rt_mutex_handle_deadlock(ret, chwalk, lock, waiter);
+ lockevent_inc(rtmutex_deadlock);
}
/*
@@ -1751,6 +1761,7 @@ static inline int __rt_mutex_slowlock_locked(struct rt_mutex_base *lock,
&waiter, wake_q);
debug_rt_mutex_free_waiter(&waiter);
+ lockevent_cond_inc(rtmutex_slow_wake, !wake_q_empty(wake_q));
return ret;
}
@@ -1823,9 +1834,12 @@ static void __sched rtlock_slowlock_locked(struct rt_mutex_base *lock,
struct task_struct *owner;
lockdep_assert_held(&lock->wait_lock);
+ lockevent_inc(rtlock_slowlock);
- if (try_to_take_rt_mutex(lock, current, NULL))
+ if (try_to_take_rt_mutex(lock, current, NULL)) {
+ lockevent_inc(rtlock_slow_acq1);
return;
+ }
rt_mutex_init_rtlock_waiter(&waiter);
@@ -1838,8 +1852,10 @@ static void __sched rtlock_slowlock_locked(struct rt_mutex_base *lock,
for (;;) {
/* Try to acquire the lock again */
- if (try_to_take_rt_mutex(lock, current, &waiter))
+ if (try_to_take_rt_mutex(lock, current, &waiter)) {
+ lockevent_inc(rtlock_slow_acq2);
break;
+ }
if (&waiter == rt_mutex_top_waiter(lock))
owner = rt_mutex_owner(lock);
@@ -1847,8 +1863,10 @@ static void __sched rtlock_slowlock_locked(struct rt_mutex_base *lock,
owner = NULL;
raw_spin_unlock_irq_wake(&lock->wait_lock, wake_q);
- if (!owner || !rtmutex_spin_on_owner(lock, &waiter, owner))
+ if (!owner || !rtmutex_spin_on_owner(lock, &waiter, owner)) {
+ lockevent_inc(rtlock_slow_sleep);
schedule_rtlock();
+ }
raw_spin_lock_irq(&lock->wait_lock);
set_current_state(TASK_RTLOCK_WAIT);
@@ -1865,6 +1883,7 @@ static void __sched rtlock_slowlock_locked(struct rt_mutex_base *lock,
debug_rt_mutex_free_waiter(&waiter);
trace_contention_end(lock, 0);
+ lockevent_cond_inc(rtlock_slow_wake, !wake_q_empty(wake_q));
}
static __always_inline void __sched rtlock_slowlock(struct rt_mutex_base *lock)
diff --git a/mm/memory.c b/mm/memory.c
index fb7b8dc75167..4f6d9766a046 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -6834,10 +6834,8 @@ void __might_fault(const char *file, int line)
if (pagefault_disabled())
return;
__might_sleep(file, line);
-#if defined(CONFIG_DEBUG_ATOMIC_SLEEP)
if (current->mm)
might_lock_read(&current->mm->mmap_lock);
-#endif
}
EXPORT_SYMBOL(__might_fault);
#endif
diff --git a/rust/helpers/helpers.c b/rust/helpers/helpers.c
index de2341cfd917..e1c21eba9b15 100644
--- a/rust/helpers/helpers.c
+++ b/rust/helpers/helpers.c
@@ -31,6 +31,7 @@
#include "signal.c"
#include "slab.c"
#include "spinlock.c"
+#include "sync.c"
#include "task.c"
#include "uaccess.c"
#include "vmalloc.c"
diff --git a/rust/helpers/sync.c b/rust/helpers/sync.c
new file mode 100644
index 000000000000..ff7e68b48810
--- /dev/null
+++ b/rust/helpers/sync.c
@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/lockdep.h>
+
+void rust_helper_lockdep_register_key(struct lock_class_key *k)
+{
+ lockdep_register_key(k);
+}
+
+void rust_helper_lockdep_unregister_key(struct lock_class_key *k)
+{
+ lockdep_unregister_key(k);
+}
diff --git a/rust/kernel/sync.rs b/rust/kernel/sync.rs
index 16eab9138b2b..4104bc26471a 100644
--- a/rust/kernel/sync.rs
+++ b/rust/kernel/sync.rs
@@ -5,6 +5,8 @@
//! This module contains the kernel APIs related to synchronisation that have been ported or
//! wrapped for usage by Rust code in the kernel.
+use crate::pin_init;
+use crate::prelude::*;
use crate::types::Opaque;
mod arc;
@@ -23,15 +25,64 @@ pub use locked_by::LockedBy;
/// Represents a lockdep class. It's a wrapper around C's `lock_class_key`.
#[repr(transparent)]
-pub struct LockClassKey(Opaque<bindings::lock_class_key>);
+#[pin_data(PinnedDrop)]
+pub struct LockClassKey {
+ #[pin]
+ inner: Opaque<bindings::lock_class_key>,
+}
// SAFETY: `bindings::lock_class_key` is designed to be used concurrently from multiple threads and
// provides its own synchronization.
unsafe impl Sync for LockClassKey {}
impl LockClassKey {
+ /// Initializes a dynamically allocated lock class key. In the common case of using a
+ /// statically allocated lock class key, the static_lock_class! macro should be used instead.
+ ///
+ /// # Example
+ /// ```
+ /// # use kernel::{c_str, stack_pin_init};
+ /// # use kernel::alloc::KBox;
+ /// # use kernel::types::ForeignOwnable;
+ /// # use kernel::sync::{LockClassKey, SpinLock};
+ ///
+ /// let key = KBox::pin_init(LockClassKey::new_dynamic(), GFP_KERNEL)?;
+ /// let key_ptr = key.into_foreign();
+ ///
+ /// {
+ /// stack_pin_init!(let num: SpinLock<u32> = SpinLock::new(
+ /// 0,
+ /// c_str!("my_spinlock"),
+ /// // SAFETY: `key_ptr` is returned by the above `into_foreign()`, whose
+ /// // `from_foreign()` has not yet been called.
+ /// unsafe { <Pin<KBox<LockClassKey>> as ForeignOwnable>::borrow(key_ptr) }
+ /// ));
+ /// }
+ ///
+ /// // SAFETY: We dropped `num`, the only use of the key, so the result of the previous
+ /// // `borrow` has also been dropped. Thus, it's safe to use from_foreign.
+ /// unsafe { drop(<Pin<KBox<LockClassKey>> as ForeignOwnable>::from_foreign(key_ptr)) };
+ ///
+ /// # Ok::<(), Error>(())
+ /// ```
+ pub fn new_dynamic() -> impl PinInit<Self> {
+ pin_init!(Self {
+ // SAFETY: lockdep_register_key expects an uninitialized block of memory
+ inner <- Opaque::ffi_init(|slot| unsafe { bindings::lockdep_register_key(slot) })
+ })
+ }
+
pub(crate) fn as_ptr(&self) -> *mut bindings::lock_class_key {
- self.0.get()
+ self.inner.get()
+ }
+}
+
+#[pinned_drop]
+impl PinnedDrop for LockClassKey {
+ fn drop(self: Pin<&mut Self>) {
+ // SAFETY: self.as_ptr was registered with lockdep and self is pinned, so the address
+ // hasn't changed. Thus, it's safe to pass to unregister.
+ unsafe { bindings::lockdep_unregister_key(self.as_ptr()) }
}
}
@@ -44,7 +95,7 @@ macro_rules! static_lock_class {
// SAFETY: lockdep expects uninitialized memory when it's handed a statically allocated
// lock_class_key
unsafe { ::core::mem::MaybeUninit::uninit().assume_init() };
- &CLASS
+ $crate::prelude::Pin::static_ref(&CLASS)
}};
}
diff --git a/rust/kernel/sync/condvar.rs b/rust/kernel/sync/condvar.rs
index 7df565038d7d..fbf68ada582f 100644
--- a/rust/kernel/sync/condvar.rs
+++ b/rust/kernel/sync/condvar.rs
@@ -11,12 +11,13 @@ use crate::{
init::PinInit,
pin_init,
str::CStr,
- task::{MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE, TASK_NORMAL, TASK_UNINTERRUPTIBLE},
+ task::{
+ MAX_SCHEDULE_TIMEOUT, TASK_FREEZABLE, TASK_INTERRUPTIBLE, TASK_NORMAL, TASK_UNINTERRUPTIBLE,
+ },
time::Jiffies,
types::Opaque,
};
-use core::marker::PhantomPinned;
-use core::ptr;
+use core::{marker::PhantomPinned, pin::Pin, ptr};
use macros::pin_data;
/// Creates a [`CondVar`] initialiser with the given name and a newly-created lock class.
@@ -101,7 +102,7 @@ unsafe impl Sync for CondVar {}
impl CondVar {
/// Constructs a new condvar initialiser.
- pub fn new(name: &'static CStr, key: &'static LockClassKey) -> impl PinInit<Self> {
+ pub fn new(name: &'static CStr, key: Pin<&'static LockClassKey>) -> impl PinInit<Self> {
pin_init!(Self {
_pin: PhantomPinned,
// SAFETY: `slot` is valid while the closure is called and both `name` and `key` have
@@ -159,6 +160,25 @@ impl CondVar {
crate::current!().signal_pending()
}
+ /// Releases the lock and waits for a notification in interruptible and freezable mode.
+ ///
+ /// The process is allowed to be frozen during this sleep. No lock should be held when calling
+ /// this function, and there is a lockdep assertion for this. Freezing a task that holds a lock
+ /// can trivially deadlock vs another task that needs that lock to complete before it too can
+ /// hit freezable.
+ #[must_use = "wait_interruptible_freezable returns if a signal is pending, so the caller must check the return value"]
+ pub fn wait_interruptible_freezable<T: ?Sized, B: Backend>(
+ &self,
+ guard: &mut Guard<'_, T, B>,
+ ) -> bool {
+ self.wait_internal(
+ TASK_INTERRUPTIBLE | TASK_FREEZABLE,
+ guard,
+ MAX_SCHEDULE_TIMEOUT,
+ );
+ crate::current!().signal_pending()
+ }
+
/// Releases the lock and waits for a notification in interruptible mode.
///
/// Atomically releases the given lock (whose ownership is proven by the guard) and puts the
diff --git a/rust/kernel/sync/lock.rs b/rust/kernel/sync/lock.rs
index eb80048e0110..360a10a9216d 100644
--- a/rust/kernel/sync/lock.rs
+++ b/rust/kernel/sync/lock.rs
@@ -12,7 +12,7 @@ use crate::{
str::CStr,
types::{NotThreadSafe, Opaque, ScopeGuard},
};
-use core::{cell::UnsafeCell, marker::PhantomPinned};
+use core::{cell::UnsafeCell, marker::PhantomPinned, pin::Pin};
use macros::pin_data;
pub mod mutex;
@@ -129,7 +129,7 @@ unsafe impl<T: ?Sized + Send, B: Backend> Sync for Lock<T, B> {}
impl<T, B: Backend> Lock<T, B> {
/// Constructs a new lock initialiser.
- pub fn new(t: T, name: &'static CStr, key: &'static LockClassKey) -> impl PinInit<Self> {
+ pub fn new(t: T, name: &'static CStr, key: Pin<&'static LockClassKey>) -> impl PinInit<Self> {
pin_init!(Self {
data: UnsafeCell::new(t),
_pin: PhantomPinned,
@@ -199,7 +199,36 @@ pub struct Guard<'a, T: ?Sized, B: Backend> {
// SAFETY: `Guard` is sync when the data protected by the lock is also sync.
unsafe impl<T: Sync + ?Sized, B: Backend> Sync for Guard<'_, T, B> {}
-impl<T: ?Sized, B: Backend> Guard<'_, T, B> {
+impl<'a, T: ?Sized, B: Backend> Guard<'a, T, B> {
+ /// Returns the lock that this guard originates from.
+ ///
+ /// # Examples
+ ///
+ /// The following example shows how to use [`Guard::lock_ref()`] to assert the corresponding
+ /// lock is held.
+ ///
+ /// ```
+ /// # use kernel::{new_spinlock, stack_pin_init, sync::lock::{Backend, Guard, Lock}};
+ ///
+ /// fn assert_held<T, B: Backend>(guard: &Guard<'_, T, B>, lock: &Lock<T, B>) {
+ /// // Address-equal means the same lock.
+ /// assert!(core::ptr::eq(guard.lock_ref(), lock));
+ /// }
+ ///
+ /// // Creates a new lock on the stack.
+ /// stack_pin_init!{
+ /// let l = new_spinlock!(42)
+ /// }
+ ///
+ /// let g = l.lock();
+ ///
+ /// // `g` originates from `l`.
+ /// assert_held(&g, &l);
+ /// ```
+ pub fn lock_ref(&self) -> &'a Lock<T, B> {
+ self.lock
+ }
+
pub(crate) fn do_unlocked<U>(&mut self, cb: impl FnOnce() -> U) -> U {
// SAFETY: The caller owns the lock, so it is safe to unlock it.
unsafe { B::unlock(self.lock.state.get(), &self.state) };
diff --git a/rust/kernel/sync/lock/global.rs b/rust/kernel/sync/lock/global.rs
index 480ee724e3cc..d65f94b5caf2 100644
--- a/rust/kernel/sync/lock/global.rs
+++ b/rust/kernel/sync/lock/global.rs
@@ -13,6 +13,7 @@ use crate::{
use core::{
cell::UnsafeCell,
marker::{PhantomData, PhantomPinned},
+ pin::Pin,
};
/// Trait implemented for marker types for global locks.
@@ -26,7 +27,7 @@ pub trait GlobalLockBackend {
/// The backend used for this global lock.
type Backend: Backend + 'static;
/// The class for this global lock.
- fn get_lock_class() -> &'static LockClassKey;
+ fn get_lock_class() -> Pin<&'static LockClassKey>;
}
/// Type used for global locks.
@@ -270,7 +271,7 @@ macro_rules! global_lock {
type Item = $valuety;
type Backend = $crate::global_lock_inner!(backend $kind);
- fn get_lock_class() -> &'static $crate::sync::LockClassKey {
+ fn get_lock_class() -> Pin<&'static $crate::sync::LockClassKey> {
$crate::static_lock_class!()
}
}
diff --git a/rust/kernel/sync/poll.rs b/rust/kernel/sync/poll.rs
index d5f17153b424..c4934f82d68b 100644
--- a/rust/kernel/sync/poll.rs
+++ b/rust/kernel/sync/poll.rs
@@ -89,7 +89,7 @@ pub struct PollCondVar {
impl PollCondVar {
/// Constructs a new condvar initialiser.
- pub fn new(name: &'static CStr, key: &'static LockClassKey) -> impl PinInit<Self> {
+ pub fn new(name: &'static CStr, key: Pin<&'static LockClassKey>) -> impl PinInit<Self> {
pin_init!(Self {
inner <- CondVar::new(name, key),
})
diff --git a/rust/kernel/task.rs b/rust/kernel/task.rs
index 38da555a2bdb..0e40a3dc0410 100644
--- a/rust/kernel/task.rs
+++ b/rust/kernel/task.rs
@@ -23,6 +23,8 @@ pub const MAX_SCHEDULE_TIMEOUT: c_long = c_long::MAX;
pub const TASK_INTERRUPTIBLE: c_int = bindings::TASK_INTERRUPTIBLE as c_int;
/// Bitmask for tasks that are sleeping in an uninterruptible state.
pub const TASK_UNINTERRUPTIBLE: c_int = bindings::TASK_UNINTERRUPTIBLE as c_int;
+/// Bitmask for tasks that are sleeping in a freezable state.
+pub const TASK_FREEZABLE: c_int = bindings::TASK_FREEZABLE as c_int;
/// Convenience constant for waking up tasks regardless of whether they are in interruptible or
/// uninterruptible sleep.
pub const TASK_NORMAL: c_uint = bindings::TASK_NORMAL as c_uint;
diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs
index 4cf9a5a9b6c3..f98bd02b838f 100644
--- a/rust/kernel/workqueue.rs
+++ b/rust/kernel/workqueue.rs
@@ -369,7 +369,7 @@ unsafe impl<T: ?Sized, const ID: u64> Sync for Work<T, ID> {}
impl<T: ?Sized, const ID: u64> Work<T, ID> {
/// Creates a new instance of [`Work`].
#[inline]
- pub fn new(name: &'static CStr, key: &'static LockClassKey) -> impl PinInit<Self>
+ pub fn new(name: &'static CStr, key: Pin<&'static LockClassKey>) -> impl PinInit<Self>
where
T: WorkItem<ID>,
{
generated by cgit v1.2.3 (git 2.46.0) at 2025-07-31 05:29:09 +0000