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-rw-r--r--kernel/lockdep.c528
-rw-r--r--kernel/lockdep_internals.h45
-rw-r--r--kernel/lockdep_proc.c22
-rw-r--r--kernel/lockdep_states.h9
-rw-r--r--kernel/mutex-debug.c9
-rw-r--r--kernel/mutex-debug.h18
-rw-r--r--kernel/mutex.c121
-rw-r--r--kernel/mutex.h22
-rw-r--r--kernel/sched.c71
-rw-r--r--kernel/sched_features.h1
-rw-r--r--kernel/timer.c68
11 files changed, 597 insertions, 317 deletions
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 06b0c3568f0..3673a3f44d9 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -41,6 +41,7 @@
#include <linux/utsname.h>
#include <linux/hash.h>
#include <linux/ftrace.h>
+#include <linux/stringify.h>
#include <asm/sections.h>
@@ -310,12 +311,14 @@ EXPORT_SYMBOL(lockdep_on);
#if VERBOSE
# define HARDIRQ_VERBOSE 1
# define SOFTIRQ_VERBOSE 1
+# define RECLAIM_VERBOSE 1
#else
# define HARDIRQ_VERBOSE 0
# define SOFTIRQ_VERBOSE 0
+# define RECLAIM_VERBOSE 0
#endif
-#if VERBOSE || HARDIRQ_VERBOSE || SOFTIRQ_VERBOSE
+#if VERBOSE || HARDIRQ_VERBOSE || SOFTIRQ_VERBOSE || RECLAIM_VERBOSE
/*
* Quick filtering for interesting events:
*/
@@ -443,17 +446,18 @@ atomic_t nr_find_usage_backwards_recursions;
* Locking printouts:
*/
+#define __USAGE(__STATE) \
+ [LOCK_USED_IN_##__STATE] = "IN-"__stringify(__STATE)"-W", \
+ [LOCK_ENABLED_##__STATE] = __stringify(__STATE)"-ON-W", \
+ [LOCK_USED_IN_##__STATE##_READ] = "IN-"__stringify(__STATE)"-R",\
+ [LOCK_ENABLED_##__STATE##_READ] = __stringify(__STATE)"-ON-R",
+
static const char *usage_str[] =
{
- [LOCK_USED] = "initial-use ",
- [LOCK_USED_IN_HARDIRQ] = "in-hardirq-W",
- [LOCK_USED_IN_SOFTIRQ] = "in-softirq-W",
- [LOCK_ENABLED_SOFTIRQS] = "softirq-on-W",
- [LOCK_ENABLED_HARDIRQS] = "hardirq-on-W",
- [LOCK_USED_IN_HARDIRQ_READ] = "in-hardirq-R",
- [LOCK_USED_IN_SOFTIRQ_READ] = "in-softirq-R",
- [LOCK_ENABLED_SOFTIRQS_READ] = "softirq-on-R",
- [LOCK_ENABLED_HARDIRQS_READ] = "hardirq-on-R",
+#define LOCKDEP_STATE(__STATE) __USAGE(__STATE)
+#include "lockdep_states.h"
+#undef LOCKDEP_STATE
+ [LOCK_USED] = "INITIAL USE",
};
const char * __get_key_name(struct lockdep_subclass_key *key, char *str)
@@ -461,46 +465,45 @@ const char * __get_key_name(struct lockdep_subclass_key *key, char *str)
return kallsyms_lookup((unsigned long)key, NULL, NULL, NULL, str);
}
-void
-get_usage_chars(struct lock_class *class, char *c1, char *c2, char *c3, char *c4)
+static inline unsigned long lock_flag(enum lock_usage_bit bit)
{
- *c1 = '.', *c2 = '.', *c3 = '.', *c4 = '.';
-
- if (class->usage_mask & LOCKF_USED_IN_HARDIRQ)
- *c1 = '+';
- else
- if (class->usage_mask & LOCKF_ENABLED_HARDIRQS)
- *c1 = '-';
+ return 1UL << bit;
+}
- if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ)
- *c2 = '+';
- else
- if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS)
- *c2 = '-';
+static char get_usage_char(struct lock_class *class, enum lock_usage_bit bit)
+{
+ char c = '.';
- if (class->usage_mask & LOCKF_ENABLED_HARDIRQS_READ)
- *c3 = '-';
- if (class->usage_mask & LOCKF_USED_IN_HARDIRQ_READ) {
- *c3 = '+';
- if (class->usage_mask & LOCKF_ENABLED_HARDIRQS_READ)
- *c3 = '?';
+ if (class->usage_mask & lock_flag(bit + 2))
+ c = '+';
+ if (class->usage_mask & lock_flag(bit)) {
+ c = '-';
+ if (class->usage_mask & lock_flag(bit + 2))
+ c = '?';
}
- if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS_READ)
- *c4 = '-';
- if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ_READ) {
- *c4 = '+';
- if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS_READ)
- *c4 = '?';
- }
+ return c;
+}
+
+void get_usage_chars(struct lock_class *class, char usage[LOCK_USAGE_CHARS])
+{
+ int i = 0;
+
+#define LOCKDEP_STATE(__STATE) \
+ usage[i++] = get_usage_char(class, LOCK_USED_IN_##__STATE); \
+ usage[i++] = get_usage_char(class, LOCK_USED_IN_##__STATE##_READ);
+#include "lockdep_states.h"
+#undef LOCKDEP_STATE
+
+ usage[i] = '\0';
}
static void print_lock_name(struct lock_class *class)
{
- char str[KSYM_NAME_LEN], c1, c2, c3, c4;
+ char str[KSYM_NAME_LEN], usage[LOCK_USAGE_CHARS];
const char *name;
- get_usage_chars(class, &c1, &c2, &c3, &c4);
+ get_usage_chars(class, usage);
name = class->name;
if (!name) {
@@ -513,7 +516,7 @@ static void print_lock_name(struct lock_class *class)
if (class->subclass)
printk("/%d", class->subclass);
}
- printk("){%c%c%c%c}", c1, c2, c3, c4);
+ printk("){%s}", usage);
}
static void print_lockdep_cache(struct lockdep_map *lock)
@@ -1263,9 +1266,49 @@ check_usage(struct task_struct *curr, struct held_lock *prev,
bit_backwards, bit_forwards, irqclass);
}
-static int
-check_prev_add_irq(struct task_struct *curr, struct held_lock *prev,
- struct held_lock *next)
+static const char *state_names[] = {
+#define LOCKDEP_STATE(__STATE) \
+ __stringify(__STATE),
+#include "lockdep_states.h"
+#undef LOCKDEP_STATE
+};
+
+static const char *state_rnames[] = {
+#define LOCKDEP_STATE(__STATE) \
+ __stringify(__STATE)"-READ",
+#include "lockdep_states.h"
+#undef LOCKDEP_STATE
+};
+
+static inline const char *state_name(enum lock_usage_bit bit)
+{
+ return (bit & 1) ? state_rnames[bit >> 2] : state_names[bit >> 2];
+}
+
+static int exclusive_bit(int new_bit)
+{
+ /*
+ * USED_IN
+ * USED_IN_READ
+ * ENABLED
+ * ENABLED_READ
+ *
+ * bit 0 - write/read
+ * bit 1 - used_in/enabled
+ * bit 2+ state
+ */
+
+ int state = new_bit & ~3;
+ int dir = new_bit & 2;
+
+ /*
+ * keep state, bit flip the direction and strip read.
+ */
+ return state | (dir ^ 2);
+}
+
+static int check_irq_usage(struct task_struct *curr, struct held_lock *prev,
+ struct held_lock *next, enum lock_usage_bit bit)
{
/*
* Prove that the new dependency does not connect a hardirq-safe
@@ -1273,38 +1316,34 @@ check_prev_add_irq(struct task_struct *curr, struct held_lock *prev,
* the backwards-subgraph starting at <prev>, and the
* forwards-subgraph starting at <next>:
*/
- if (!check_usage(curr, prev, next, LOCK_USED_IN_HARDIRQ,
- LOCK_ENABLED_HARDIRQS, "hard"))
+ if (!check_usage(curr, prev, next, bit,
+ exclusive_bit(bit), state_name(bit)))
return 0;
+ bit++; /* _READ */
+
/*
* Prove that the new dependency does not connect a hardirq-safe-read
* lock with a hardirq-unsafe lock - to achieve this we search
* the backwards-subgraph starting at <prev>, and the
* forwards-subgraph starting at <next>:
*/
- if (!check_usage(curr, prev, next, LOCK_USED_IN_HARDIRQ_READ,
- LOCK_ENABLED_HARDIRQS, "hard-read"))
+ if (!check_usage(curr, prev, next, bit,
+ exclusive_bit(bit), state_name(bit)))
return 0;
- /*
- * Prove that the new dependency does not connect a softirq-safe
- * lock with a softirq-unsafe lock - to achieve this we search
- * the backwards-subgraph starting at <prev>, and the
- * forwards-subgraph starting at <next>:
- */
- if (!check_usage(curr, prev, next, LOCK_USED_IN_SOFTIRQ,
- LOCK_ENABLED_SOFTIRQS, "soft"))
- return 0;
- /*
- * Prove that the new dependency does not connect a softirq-safe-read
- * lock with a softirq-unsafe lock - to achieve this we search
- * the backwards-subgraph starting at <prev>, and the
- * forwards-subgraph starting at <next>:
- */
- if (!check_usage(curr, prev, next, LOCK_USED_IN_SOFTIRQ_READ,
- LOCK_ENABLED_SOFTIRQS, "soft"))
+ return 1;
+}
+
+static int
+check_prev_add_irq(struct task_struct *curr, struct held_lock *prev,
+ struct held_lock *next)
+{
+#define LOCKDEP_STATE(__STATE) \
+ if (!check_irq_usage(curr, prev, next, LOCK_USED_IN_##__STATE)) \
return 0;
+#include "lockdep_states.h"
+#undef LOCKDEP_STATE
return 1;
}
@@ -1933,7 +1972,7 @@ void print_irqtrace_events(struct task_struct *curr)
print_ip_sym(curr->softirq_disable_ip);
}
-static int hardirq_verbose(struct lock_class *class)
+static int HARDIRQ_verbose(struct lock_class *class)
{
#if HARDIRQ_VERBOSE
return class_filter(class);
@@ -1941,7 +1980,7 @@ static int hardirq_verbose(struct lock_class *class)
return 0;
}
-static int softirq_verbose(struct lock_class *class)
+static int SOFTIRQ_verbose(struct lock_class *class)
{
#if SOFTIRQ_VERBOSE
return class_filter(class);
@@ -1949,185 +1988,94 @@ static int softirq_verbose(struct lock_class *class)
return 0;
}
+static int RECLAIM_FS_verbose(struct lock_class *class)
+{
+#if RECLAIM_VERBOSE
+ return class_filter(class);
+#endif
+ return 0;
+}
+
#define STRICT_READ_CHECKS 1
-static int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
- enum lock_usage_bit new_bit)
+static int (*state_verbose_f[])(struct lock_class *class) = {
+#define LOCKDEP_STATE(__STATE) \
+ __STATE##_verbose,
+#include "lockdep_states.h"
+#undef LOCKDEP_STATE
+};
+
+static inline int state_verbose(enum lock_usage_bit bit,
+ struct lock_class *class)
{
- int ret = 1;
+ return state_verbose_f[bit >> 2](class);
+}
- switch(new_bit) {
- case LOCK_USED_IN_HARDIRQ:
- if (!valid_state(curr, this, new_bit, LOCK_ENABLED_HARDIRQS))
- return 0;
- if (!valid_state(curr, this, new_bit,
- LOCK_ENABLED_HARDIRQS_READ))
- return 0;
- /*
- * just marked it hardirq-safe, check that this lock
- * took no hardirq-unsafe lock in the past:
- */
- if (!check_usage_forwards(curr, this,
- LOCK_ENABLED_HARDIRQS, "hard"))
- return 0;
-#if STRICT_READ_CHECKS
- /*
- * just marked it hardirq-safe, check that this lock
- * took no hardirq-unsafe-read lock in the past:
- */
- if (!check_usage_forwards(curr, this,
- LOCK_ENABLED_HARDIRQS_READ, "hard-read"))
- return 0;
-#endif
- if (hardirq_verbose(hlock_class(this)))
- ret = 2;
- break;
- case LOCK_USED_IN_SOFTIRQ:
- if (!valid_state(curr, this, new_bit, LOCK_ENABLED_SOFTIRQS))
- return 0;
- if (!valid_state(curr, this, new_bit,
- LOCK_ENABLED_SOFTIRQS_READ))
- return 0;
- /*
- * just marked it softirq-safe, check that this lock
- * took no softirq-unsafe lock in the past:
- */
- if (!check_usage_forwards(curr, this,
- LOCK_ENABLED_SOFTIRQS, "soft"))
- return 0;
-#if STRICT_READ_CHECKS
- /*
- * just marked it softirq-safe, check that this lock
- * took no softirq-unsafe-read lock in the past:
- */
- if (!check_usage_forwards(curr, this,
- LOCK_ENABLED_SOFTIRQS_READ, "soft-read"))
- return 0;
-#endif
- if (softirq_verbose(hlock_class(this)))
- ret = 2;
- break;
- case LOCK_USED_IN_HARDIRQ_READ:
- if (!valid_state(curr, this, new_bit, LOCK_ENABLED_HARDIRQS))
- return 0;
- /*
- * just marked it hardirq-read-safe, check that this lock
- * took no hardirq-unsafe lock in the past:
- */
- if (!check_usage_forwards(curr, this,
- LOCK_ENABLED_HARDIRQS, "hard"))
- return 0;
- if (hardirq_verbose(hlock_class(this)))
- ret = 2;
- break;
- case LOCK_USED_IN_SOFTIRQ_READ:
- if (!valid_state(curr, this, new_bit, LOCK_ENABLED_SOFTIRQS))
- return 0;
- /*
- * just marked it softirq-read-safe, check that this lock
- * took no softirq-unsafe lock in the past:
- */
- if (!check_usage_forwards(curr, this,
- LOCK_ENABLED_SOFTIRQS, "soft"))
- return 0;
- if (softirq_verbose(hlock_class(this)))
- ret = 2;
- break;
- case LOCK_ENABLED_HARDIRQS:
- if (!valid_state(curr, this, new_bit, LOCK_USED_IN_HARDIRQ))
- return 0;
- if (!valid_state(curr, this, new_bit,
- LOCK_USED_IN_HARDIRQ_READ))
- return 0;
- /*
- * just marked it hardirq-unsafe, check that no hardirq-safe
- * lock in the system ever took it in the past:
- */
- if (!check_usage_backwards(curr, this,
- LOCK_USED_IN_HARDIRQ, "hard"))
- return 0;
-#if STRICT_READ_CHECKS
- /*
- * just marked it hardirq-unsafe, check that no
- * hardirq-safe-read lock in the system ever took
- * it in the past:
- */
- if (!check_usage_backwards(curr, this,
- LOCK_USED_IN_HARDIRQ_READ, "hard-read"))
- return 0;
-#endif
- if (hardirq_verbose(hlock_class(this)))
- ret = 2;
- break;
- case LOCK_ENABLED_SOFTIRQS:
- if (!valid_state(curr, this, new_bit, LOCK_USED_IN_SOFTIRQ))
- return 0;
- if (!valid_state(curr, this, new_bit,
- LOCK_USED_IN_SOFTIRQ_READ))
- return 0;
- /*
- * just marked it softirq-unsafe, check that no softirq-safe
- * lock in the system ever took it in the past:
- */
- if (!check_usage_backwards(curr, this,
- LOCK_USED_IN_SOFTIRQ, "soft"))
- return 0;
-#if STRICT_READ_CHECKS
- /*
- * just marked it softirq-unsafe, check that no
- * softirq-safe-read lock in the system ever took
- * it in the past:
- */
- if (!check_usage_backwards(curr, this,
- LOCK_USED_IN_SOFTIRQ_READ, "soft-read"))
- return 0;
-#endif
- if (softirq_verbose(hlock_class(this)))
- ret = 2;
- break;
- case LOCK_ENABLED_HARDIRQS_READ:
- if (!valid_state(curr, this, new_bit, LOCK_USED_IN_HARDIRQ))
- return 0;
-#if STRICT_READ_CHECKS
- /*
- * just marked it hardirq-read-unsafe, check that no
- * hardirq-safe lock in the system ever took it in the past:
- */
- if (!check_usage_backwards(curr, this,
- LOCK_USED_IN_HARDIRQ, "hard"))
- return 0;
-#endif
- if (hardirq_verbose(hlock_class(this)))
- ret = 2;
- break;
- case LOCK_ENABLED_SOFTIRQS_READ:
- if (!valid_state(curr, this, new_bit, LOCK_USED_IN_SOFTIRQ))
+typedef int (*check_usage_f)(struct task_struct *, struct held_lock *,
+ enum lock_usage_bit bit, const char *name);
+
+static int
+mark_lock_irq(struct task_struct *curr, struct held_lock *this, int new_bit)
+{
+ int excl_bit = exclusive_bit(new_bit);
+ int read = new_bit & 1;
+ int dir = new_bit & 2;
+
+ /*
+ * mark USED_IN has to look forwards -- to ensure no dependency
+ * has ENABLED state, which would allow recursion deadlocks.
+ *
+ * mark ENABLED has to look backwards -- to ensure no dependee
+ * has USED_IN state, which, again, would allow recursion deadlocks.
+ */
+ check_usage_f usage = dir ?
+ check_usage_backwards : check_usage_forwards;
+
+ /*
+ * Validate that this particular lock does not have conflicting
+ * usage states.
+ */
+ if (!valid_state(curr, this, new_bit, excl_bit))
+ return 0;
+
+ /*
+ * Validate that the lock dependencies don't have conflicting usage
+ * states.
+ */
+ if ((!read || !dir || STRICT_READ_CHECKS) &&
+ !usage(curr, this, excl_bit, state_name(new_bit)))
+ return 0;
+
+ /*
+ * Check for read in write conflicts
+ */
+ if (!read) {
+ if (!valid_state(curr, this, new_bit, excl_bit + 1))
return 0;
-#if STRICT_READ_CHECKS
- /*
- * just marked it softirq-read-unsafe, check that no
- * softirq-safe lock in the system ever took it in the past:
- */
- if (!check_usage_backwards(curr, this,
- LOCK_USED_IN_SOFTIRQ, "soft"))
+
+ if (STRICT_READ_CHECKS &&
+ !usage(curr, this, excl_bit + 1,
+ state_name(new_bit + 1)))
return 0;
-#endif
- if (softirq_verbose(hlock_class(this)))
- ret = 2;
- break;
- default:
- WARN_ON(1);
- break;
}
- return ret;
+ if (state_verbose(new_bit, hlock_class(this)))
+ return 2;
+
+ return 1;
}
+enum mark_type {
+#define LOCKDEP_STATE(__STATE) __STATE,
+#include "lockdep_states.h"
+#undef LOCKDEP_STATE
+};
+
/*
* Mark all held locks with a usage bit:
*/
static int
-mark_held_locks(struct task_struct *curr, int hardirq)
+mark_held_locks(struct task_struct *curr, enum mark_type mark)
{
enum lock_usage_bit usage_bit;
struct held_lock *hlock;
@@ -2136,17 +2084,12 @@ mark_held_locks(struct task_struct *curr, int hardirq)
for (i = 0; i < curr->lockdep_depth; i++) {
hlock = curr->held_locks + i;
- if (hardirq) {
- if (hlock->read)
- usage_bit = LOCK_ENABLED_HARDIRQS_READ;
- else
- usage_bit = LOCK_ENABLED_HARDIRQS;
- } else {
- if (hlock->read)
- usage_bit = LOCK_ENABLED_SOFTIRQS_READ;
- else
- usage_bit = LOCK_ENABLED_SOFTIRQS;
- }
+ usage_bit = 2 + (mark << 2); /* ENABLED */
+ if (hlock->read)
+ usage_bit += 1; /* READ */
+
+ BUG_ON(usage_bit >= LOCK_USAGE_STATES);
+
if (!mark_lock(curr, hlock, usage_bit))
return 0;
}
@@ -2200,7 +2143,7 @@ void trace_hardirqs_on_caller(unsigned long ip)
* We are going to turn hardirqs on, so set the
* usage bit for all held locks:
*/
- if (!mark_held_locks(curr, 1))
+ if (!mark_held_locks(curr, HARDIRQ))
return;
/*
* If we have softirqs enabled, then set the usage
@@ -2208,7 +2151,7 @@ void trace_hardirqs_on_caller(unsigned long ip)
* this bit from being set before)
*/
if (curr->softirqs_enabled)
- if (!mark_held_locks(curr, 0))
+ if (!mark_held_locks(curr, SOFTIRQ))
return;
curr->hardirq_enable_ip = ip;
@@ -2288,7 +2231,7 @@ void trace_softirqs_on(unsigned long ip)
* enabled too:
*/
if (curr->hardirqs_enabled)
- mark_held_locks(curr, 0);
+ mark_held_locks(curr, SOFTIRQ);
}
/*
@@ -2317,6 +2260,48 @@ void trace_softirqs_off(unsigned long ip)
debug_atomic_inc(&redundant_softirqs_off);
}
+static void __lockdep_trace_alloc(gfp_t gfp_mask, unsigned long flags)
+{
+ struct task_struct *curr = current;
+
+ if (unlikely(!debug_locks))
+ return;
+
+ /* no reclaim without waiting on it */
+ if (!(gfp_mask & __GFP_WAIT))
+ return;
+
+ /* this guy won't enter reclaim */
+ if ((curr->flags & PF_MEMALLOC) && !(gfp_mask & __GFP_NOMEMALLOC))
+ return;
+
+ /* We're only interested __GFP_FS allocations for now */
+ if (!(gfp_mask & __GFP_FS))
+ return;
+
+ if (DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags)))
+ return;
+
+ mark_held_locks(curr, RECLAIM_FS);
+}
+
+static void check_flags(unsigned long flags);
+
+void lockdep_trace_alloc(gfp_t gfp_mask)
+{
+ unsigned long flags;
+
+ if (unlikely(current->lockdep_recursion))
+ return;
+
+ raw_local_irq_save(flags);
+ check_flags(flags);
+ current->lockdep_recursion = 1;
+ __lockdep_trace_alloc(gfp_mask, flags);
+ current->lockdep_recursion = 0;
+ raw_local_irq_restore(flags);
+}
+
static int mark_irqflags(struct task_struct *curr, struct held_lock *hlock)
{
/*
@@ -2345,19 +2330,35 @@ static int mark_irqflags(struct task_struct *curr, struct held_lock *hlock)
if (!hlock->hardirqs_off) {
if (hlock->read) {
if (!mark_lock(curr, hlock,
- LOCK_ENABLED_HARDIRQS_READ))
+ LOCK_ENABLED_HARDIRQ_READ))
return 0;
if (curr->softirqs_enabled)
if (!mark_lock(curr, hlock,
- LOCK_ENABLED_SOFTIRQS_READ))
+ LOCK_ENABLED_SOFTIRQ_READ))
return 0;
} else {
if (!mark_lock(curr, hlock,
- LOCK_ENABLED_HARDIRQS))
+ LOCK_ENABLED_HARDIRQ))
return 0;
if (curr->softirqs_enabled)
if (!mark_lock(curr, hlock,
- LOCK_ENABLED_SOFTIRQS))
+ LOCK_ENABLED_SOFTIRQ))
+ return 0;
+ }
+ }
+
+ /*
+ * We reuse the irq context infrastructure more broadly as a general
+ * context checking code. This tests GFP_FS recursion (a lock taken
+ * during reclaim for a GFP_FS allocation is held over a GFP_FS
+ * allocation).
+ */
+ if (!hlock->trylock && (curr->lockdep_reclaim_gfp & __GFP_FS)) {
+ if (hlock->read) {
+ if (!mark_lock(curr, hlock, LOCK_USED_IN_RECLAIM_FS_READ))
+ return 0;
+ } else {
+ if (!mark_lock(curr, hlock, LOCK_USED_IN_RECLAIM_FS))
return 0;
}
}
@@ -2412,6 +2413,10 @@ static inline int separate_irq_context(struct task_struct *curr,
return 0;
}
+void lockdep_trace_alloc(gfp_t gfp_mask)
+{
+}
+
#endif
/*
@@ -2445,14 +2450,13 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this,
return 0;
switch (new_bit) {
- case LOCK_USED_IN_HARDIRQ:
- case LOCK_USED_IN_SOFTIRQ:
- case LOCK_USED_IN_HARDIRQ_READ:
- case LOCK_USED_IN_SOFTIRQ_READ:
- case LOCK_ENABLED_HARDIRQS:
- case LOCK_ENABLED_SOFTIRQS:
- case LOCK_ENABLED_HARDIRQS_READ:
- case LOCK_ENABLED_SOFTIRQS_READ:
+#define LOCKDEP_STATE(__STATE) \
+ case LOCK_USED_IN_##__STATE: \
+ case LOCK_USED_IN_##__STATE##_READ: \
+ case LOCK_ENABLED_##__STATE: \
+ case LOCK_ENABLED_##__STATE##_READ:
+#include "lockdep_states.h"
+#undef LOCKDEP_STATE
ret = mark_lock_irq(curr, this, new_bit);
if (!ret)
return 0;
@@ -2966,6 +2970,16 @@ void lock_release(struct lockdep_map *lock, int nested,
}
EXPORT_SYMBOL_GPL(lock_release);
+void lockdep_set_current_reclaim_state(gfp_t gfp_mask)
+{
+ current->lockdep_reclaim_gfp = gfp_mask;
+}
+
+void lockdep_clear_current_reclaim_state(void)
+{
+ current->lockdep_reclaim_gfp = 0;
+}
+
#ifdef CONFIG_LOCK_STAT
static int
print_lock_contention_bug(struct task_struct *curr, struct lockdep_map *lock,
diff --git a/kernel/lockdep_internals.h b/kernel/lockdep_internals.h
index 56b196932c0..a2cc7e9a6e8 100644
--- a/kernel/lockdep_internals.h
+++ b/kernel/lockdep_internals.h
@@ -7,6 +7,45 @@
*/
/*
+ * Lock-class usage-state bits:
+ */
+enum lock_usage_bit {
+#define LOCKDEP_STATE(__STATE) \
+ LOCK_USED_IN_##__STATE, \
+ LOCK_USED_IN_##__STATE##_READ, \
+ LOCK_ENABLED_##__STATE, \
+ LOCK_ENABLED_##__STATE##_READ,
+#include "lockdep_states.h"
+#undef LOCKDEP_STATE
+ LOCK_USED,
+ LOCK_USAGE_STATES
+};
+
+/*
+ * Usage-state bitmasks:
+ */
+#define __LOCKF(__STATE) LOCKF_##__STATE = (1 << LOCK_##__STATE),
+
+enum {
+#define LOCKDEP_STATE(__STATE) \
+ __LOCKF(USED_IN_##__STATE) \
+ __LOCKF(USED_IN_##__STATE##_READ) \
+ __LOCKF(ENABLED_##__STATE) \
+ __LOCKF(ENABLED_##__STATE##_READ)
+#include "lockdep_states.h"
+#undef LOCKDEP_STATE
+ __LOCKF(USED)
+};
+
+#define LOCKF_ENABLED_IRQ (LOCKF_ENABLED_HARDIRQ | LOCKF_ENABLED_SOFTIRQ)
+#define LOCKF_USED_IN_IRQ (LOCKF_USED_IN_HARDIRQ | LOCKF_USED_IN_SOFTIRQ)
+
+#define LOCKF_ENABLED_IRQ_READ \
+ (LOCKF_ENABLED_HARDIRQ_READ | LOCKF_ENABLED_SOFTIRQ_READ)
+#define LOCKF_USED_IN_IRQ_READ \
+ (LOCKF_USED_IN_HARDIRQ_READ | LOCKF_USED_IN_SOFTIRQ_READ)
+
+/*
* MAX_LOCKDEP_ENTRIES is the maximum number of lock dependencies
* we track.
*
@@ -31,8 +70,10 @@
extern struct list_head all_lock_classes;
extern struct lock_chain lock_chains[];
-extern void
-get_usage_chars(struct lock_class *class, char *c1, char *c2, char *c3, char *c4);
+#define LOCK_USAGE_CHARS (1+LOCK_USAGE_STATES/2)
+
+extern void get_usage_chars(struct lock_class *class,
+ char usage[LOCK_USAGE_CHARS]);
extern const char * __get_key_name(struct lockdep_subclass_key *key, char *str);
diff --git a/kernel/lockdep_proc.c b/kernel/lockdep_proc.c
index 13716b81389..d7135aa2d2c 100644
--- a/kernel/lockdep_proc.c
+++ b/kernel/lockdep_proc.c
@@ -84,7 +84,7 @@ static int l_show(struct seq_file *m, void *v)
{
struct lock_class *class = v;
struct lock_list *entry;
- char c1, c2, c3, c4;
+ char usage[LOCK_USAGE_CHARS];
if (v == SEQ_START_TOKEN) {
seq_printf(m, "all lock classes:\n");
@@ -100,8 +100,8 @@ static int l_show(struct seq_file *m, void *v)
seq_printf(m, " BD:%5ld", lockdep_count_backward_deps(class));
#endif
- get_usage_chars(class, &c1, &c2, &c3, &c4);
- seq_printf(m, " %c%c%c%c", c1, c2, c3, c4);
+ get_usage_chars(class, usage);
+ seq_printf(m, " %s", usage);
seq_printf(m, ": ");
print_name(m, class);
@@ -300,27 +300,27 @@ static int lockdep_stats_show(struct seq_file *m, void *v)
nr_uncategorized++;
if (class->usage_mask & LOCKF_USED_IN_IRQ)
nr_irq_safe++;
- if (class->usage_mask & LOCKF_ENABLED_IRQS)
+ if (class->usage_mask & LOCKF_ENABLED_IRQ)
nr_irq_unsafe++;
if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ)
nr_softirq_safe++;
- if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS)
+ if (class->usage_mask & LOCKF_ENABLED_SOFTIRQ)
nr_softirq_unsafe++;
if (class->usage_mask & LOCKF_USED_IN_HARDIRQ)
nr_hardirq_safe++;
- if (class->usage_mask & LOCKF_ENABLED_HARDIRQS)
+ if (class->usage_mask & LOCKF_ENABLED_HARDIRQ)
nr_hardirq_unsafe++;
if (class->usage_mask & LOCKF_USED_IN_IRQ_READ)
nr_irq_read_safe++;
- if (class->usage_mask & LOCKF_ENABLED_IRQS_READ)
+ if (class->usage_mask & LOCKF_ENABLED_IRQ_READ)
nr_irq_read_unsafe++;
if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ_READ)
nr_softirq_read_safe++;
- if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS_READ)
+ if (class->usage_mask & LOCKF_ENABLED_SOFTIRQ_READ)
nr_softirq_read_unsafe++;
if (class->usage_mask & LOCKF_USED_IN_HARDIRQ_READ)
nr_hardirq_read_safe++;
- if (class->usage_mask & LOCKF_ENABLED_HARDIRQS_READ)
+ if (class->usage_mask & LOCKF_ENABLED_HARDIRQ_READ)
nr_hardirq_read_unsafe++;
#ifdef CONFIG_PROVE_LOCKING
@@ -601,6 +601,10 @@ static void seq_stats(struct seq_file *m, struct lock_stat_data *data)
static void seq_header(struct seq_file *m)
{
seq_printf(m, "lock_stat version 0.3\n");
+
+ if (unlikely(!debug_locks))
+ seq_printf(m, "*WARNING* lock debugging disabled!! - possibly due to a lockdep warning\n");
+
seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1));
seq_printf(m, "%40s %14s %14s %14s %14s %14s %14s %14s %14s "
"%14s %14s\n",
diff --git a/kernel/lockdep_states.h b/kernel/lockdep_states.h
new file mode 100644
index 00000000000..995b0cc2b84
--- /dev/null
+++ b/kernel/lockdep_states.h
@@ -0,0 +1,9 @@
+/*
+ * Lockdep states,
+ *
+ * please update XXX_LOCK_USAGE_STATES in include/linux/lockdep.h whenever
+ * you add one, or come up with a nice dynamic solution.
+ */
+LOCKDEP_STATE(HARDIRQ)
+LOCKDEP_STATE(SOFTIRQ)
+LOCKDEP_STATE(RECLAIM_FS)
diff --git a/kernel/mutex-debug.c b/kernel/mutex-debug.c
index 1d94160eb53..50d022e5a56 100644
--- a/kernel/mutex-debug.c
+++ b/kernel/mutex-debug.c
@@ -26,11 +26,6 @@
/*
* Must be called with lock->wait_lock held.
*/
-void debug_mutex_set_owner(struct mutex *lock, struct thread_info *new_owner)
-{
- lock->owner = new_owner;
-}
-
void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)
{
memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter));
@@ -59,7 +54,6 @@ void debug_mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter,
/* Mark the current thread as blocked on the lock: */
ti->task->blocked_on = waiter;
- waiter->lock = lock;
}
void mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
@@ -82,7 +76,7 @@ void debug_mutex_unlock(struct mutex *lock)
DEBUG_LOCKS_WARN_ON(lock->magic != lock);
DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info());
DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next);
- DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info());
+ mutex_clear_owner(lock);
}
void debug_mutex_init(struct mutex *lock, const char *name,
@@ -95,7 +89,6 @@ void debug_mutex_init(struct mutex *lock, const char *name,
debug_check_no_locks_freed((void *)lock, sizeof(*lock));
lockdep_init_map(&lock->dep_map, name, key, 0);
#endif
- lock->owner = NULL;
lock->magic = lock;
}
diff --git a/kernel/mutex-debug.h b/kernel/mutex-debug.h
index babfbdfc534..6b2d735846a 100644
--- a/kernel/mutex-debug.h
+++ b/kernel/mutex-debug.h
@@ -13,14 +13,6 @@
/*
* This must be called with lock->wait_lock held.
*/
-extern void
-debug_mutex_set_owner(struct mutex *lock, struct thread_info *new_owner);
-
-static inline void debug_mutex_clear_owner(struct mutex *lock)
-{
- lock->owner = NULL;
-}
-
extern void debug_mutex_lock_common(struct mutex *lock,
struct mutex_waiter *waiter);
extern void debug_mutex_wake_waiter(struct mutex *lock,
@@ -35,6 +27,16 @@ extern void debug_mutex_unlock(struct mutex *lock);
extern void debug_mutex_init(struct mutex *lock, const char *name,
struct lock_class_key *key);
+static inline void mutex_set_owner(struct mutex *lock)
+{
+ lock->owner = current_thread_info();
+}
+
+static inline void mutex_clear_owner(struct mutex *lock)
+{
+ lock->owner = NULL;
+}
+
#define spin_lock_mutex(lock, flags) \
do { \
struct mutex *l = container_of(lock, struct mutex, wait_lock); \
diff --git a/kernel/mutex.c b/kernel/mutex.c
index 4f45d4b658e..5d79781394a 100644
--- a/kernel/mutex.c
+++ b/kernel/mutex.c
@@ -10,6 +10,11 @@
* Many thanks to Arjan van de Ven, Thomas Gleixner, Steven Rostedt and
* David Howells for suggestions and improvements.
*
+ * - Adaptive spinning for mutexes by Peter Zijlstra. (Ported to mainline
+ * from the -rt tree, where it was originally implemented for rtmutexes
+ * by Steven Rostedt, based on work by Gregory Haskins, Peter Morreale
+ * and Sven Dietrich.
+ *
* Also see Documentation/mutex-design.txt.
*/
#include <linux/mutex.h>
@@ -46,6 +51,7 @@ __mutex_init(struct mutex *lock, const char *name, struct lock_class_key *key)
atomic_set(&lock->count, 1);
spin_lock_init(&lock->wait_lock);
INIT_LIST_HEAD(&lock->wait_list);
+ mutex_clear_owner(lock);
debug_mutex_init(lock, name, key);
}
@@ -91,6 +97,7 @@ void inline __sched mutex_lock(struct mutex *lock)
* 'unlocked' into 'locked' state.
*/
__mutex_fastpath_lock(&lock->count, __mutex_lock_slowpath);
+ mutex_set_owner(lock);
}
EXPORT_SYMBOL(mutex_lock);
@@ -115,6 +122,14 @@ void __sched mutex_unlock(struct mutex *lock)
* The unlocking fastpath is the 0->1 transition from 'locked'
* into 'unlocked' state:
*/
+#ifndef CONFIG_DEBUG_MUTEXES
+ /*
+ * When debugging is enabled we must not clear the owner before time,
+ * the slow path will always be taken, and that clears the owner field
+ * after verifying that it was indeed current.
+ */
+ mutex_clear_owner(lock);
+#endif
__mutex_fastpath_unlock(&lock->count, __mutex_unlock_slowpath);
}
@@ -129,21 +144,75 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
{
struct task_struct *task = current;
struct mutex_waiter waiter;
- unsigned int old_val;
unsigned long flags;
+ preempt_disable();
+ mutex_acquire(&lock->dep_map, subclass, 0, ip);
+#if defined(CONFIG_SMP) && !defined(CONFIG_DEBUG_MUTEXES)
+ /*
+ * Optimistic spinning.
+ *
+ * We try to spin for acquisition when we find that there are no
+ * pending waiters and the lock owner is currently running on a
+ * (different) CPU.
+ *
+ * The rationale is that if the lock owner is running, it is likely to
+ * release the lock soon.
+ *
+ * Since this needs the lock owner, and this mutex implementation
+ * doesn't track the owner atomically in the lock field, we need to
+ * track it non-atomically.
+ *
+ * We can't do this for DEBUG_MUTEXES because that relies on wait_lock
+ * to serialize everything.
+ */
+
+ for (;;) {
+ struct thread_info *owner;
+
+ /*
+ * If there's an owner, wait for it to either
+ * release the lock or go to sleep.
+ */
+ owner = ACCESS_ONCE(lock->owner);
+ if (owner && !mutex_spin_on_owner(lock, owner))
+ break;
+
+ if (atomic_cmpxchg(&lock->count, 1, 0) == 1) {
+ lock_acquired(&lock->dep_map, ip);
+ mutex_set_owner(lock);
+ preempt_enable();
+ return 0;
+ }
+
+ /*
+ * When there's no owner, we might have preempted between the
+ * owner acquiring the lock and setting the owner field. If
+ * we're an RT task that will live-lock because we won't let
+ * the owner complete.
+ */
+ if (!owner && (need_resched() || rt_task(task)))
+ break;
+
+ /*
+ * The cpu_relax() call is a compiler barrier which forces
+ * everything in this loop to be re-loaded. We don't need
+ * memory barriers as we'll eventually observe the right
+ * values at the cost of a few extra spins.
+ */
+ cpu_relax();
+ }
+#endif
spin_lock_mutex(&lock->wait_lock, flags);
debug_mutex_lock_common(lock, &waiter);
- mutex_acquire(&lock->dep_map, subclass, 0, ip);
debug_mutex_add_waiter(lock, &waiter, task_thread_info(task));
/* add waiting tasks to the end of the waitqueue (FIFO): */
list_add_tail(&waiter.list, &lock->wait_list);
waiter.task = task;
- old_val = atomic_xchg(&lock->count, -1);
- if (old_val == 1)
+ if (atomic_xchg(&lock->count, -1) == 1)
goto done;
lock_contended(&lock->dep_map, ip);
@@ -158,8 +227,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
* that when we release the lock, we properly wake up the
* other waiters:
*/
- old_val = atomic_xchg(&lock->count, -1);
- if (old_val == 1)
+ if (atomic_xchg(&lock->count, -1) == 1)
break;
/*
@@ -173,21 +241,22 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
spin_unlock_mutex(&lock->wait_lock, flags);
debug_mutex_free_waiter(&waiter);
+ preempt_enable();
return -EINTR;
}
__set_task_state(task, state);
/* didnt get the lock, go to sleep: */
spin_unlock_mutex(&lock->wait_lock, flags);
- schedule();
+ __schedule();
spin_lock_mutex(&lock->wait_lock, flags);
}
done:
lock_acquired(&lock->dep_map, ip);
/* got the lock - rejoice! */
- mutex_remove_waiter(lock, &waiter, task_thread_info(task));
- debug_mutex_set_owner(lock, task_thread_info(task));
+ mutex_remove_waiter(lock, &waiter, current_thread_info());
+ mutex_set_owner(lock);
/* set it to 0 if there are no waiters left: */
if (likely(list_empty(&lock->wait_list)))
@@ -196,6 +265,7 @@ done:
spin_unlock_mutex(&lock->wait_lock, flags);
debug_mutex_free_waiter(&waiter);
+ preempt_enable();
return 0;
}
@@ -222,7 +292,8 @@ int __sched
mutex_lock_interruptible_nested(struct mutex *lock, unsigned int subclass)
{
might_sleep();
- return __mutex_lock_common(lock, TASK_INTERRUPTIBLE, subclass, _RET_IP_);
+ return __mutex_lock_common(lock, TASK_INTERRUPTIBLE,
+ subclass, _RET_IP_);
}
EXPORT_SYMBOL_GPL(mutex_lock_interruptible_nested);
@@ -260,8 +331,6 @@ __mutex_unlock_common_slowpath(atomic_t *lock_count, int nested)
wake_up_process(waiter->task);
}
- debug_mutex_clear_owner(lock);
-
spin_unlock_mutex(&lock->wait_lock, flags);
}
@@ -298,18 +367,30 @@ __mutex_lock_interruptible_slowpath(atomic_t *lock_count);
*/
int __sched mutex_lock_interruptible(struct mutex *lock)
{
+ int ret;
+
might_sleep();
- return __mutex_fastpath_lock_retval
+ ret = __mutex_fastpath_lock_retval
(&lock->count, __mutex_lock_interruptible_slowpath);
+ if (!ret)
+ mutex_set_owner(lock);
+
+ return ret;
}
EXPORT_SYMBOL(mutex_lock_interruptible);
int __sched mutex_lock_killable(struct mutex *lock)
{
+ int ret;
+
might_sleep();
- return __mutex_fastpath_lock_retval
+ ret = __mutex_fastpath_lock_retval
(&lock->count, __mutex_lock_killable_slowpath);
+ if (!ret)
+ mutex_set_owner(lock);
+
+ return ret;
}
EXPORT_SYMBOL(mutex_lock_killable);
@@ -352,9 +433,10 @@ static inline int __mutex_trylock_slowpath(atomic_t *lock_count)
prev = atomic_xchg(&lock->count, -1);
if (likely(prev == 1)) {
- debug_mutex_set_owner(lock, current_thread_info());
+ mutex_set_owner(lock);
mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_);
}
+
/* Set it back to 0 if there are no waiters: */
if (likely(list_empty(&lock->wait_list)))
atomic_set(&lock->count, 0);
@@ -380,8 +462,13 @@ static inline int __mutex_trylock_slowpath(atomic_t *lock_count)
*/
int __sched mutex_trylock(struct mutex *lock)
{
- return __mutex_fastpath_trylock(&lock->count,
- __mutex_trylock_slowpath);
+ int ret;
+
+ ret = __mutex_fastpath_trylock(&lock->count, __mutex_trylock_slowpath);
+ if (ret)
+ mutex_set_owner(lock);
+
+ return ret;
}
EXPORT_SYMBOL(mutex_trylock);
diff --git a/kernel/mutex.h b/kernel/mutex.h
index a075dafbb29..67578ca48f9 100644
--- a/kernel/mutex.h
+++ b/kernel/mutex.h
@@ -16,8 +16,26 @@
#define mutex_remove_waiter(lock, waiter, ti) \
__list_del((waiter)->list.prev, (waiter)->list.next)
-#define debug_mutex_set_owner(lock, new_owner) do { } while (0)
-#define debug_mutex_clear_owner(lock) do { } while (0)
+#ifdef CONFIG_SMP
+static inline void mutex_set_owner(struct mutex *lock)
+{
+ lock->owner = current_thread_info();
+}
+
+static inline void mutex_clear_owner(struct mutex *lock)
+{
+ lock->owner = NULL;
+}
+#else
+static inline void mutex_set_owner(struct mutex *lock)
+{
+}
+
+static inline void mutex_clear_owner(struct mutex *lock)
+{
+}
+#endif
+
#define debug_mutex_wake_waiter(lock, waiter) do { } while (0)
#define debug_mutex_free_waiter(waiter) do { } while (0)
#define debug_mutex_add_waiter(lock, waiter, ti) do { } while (0)
diff --git a/kernel/sched.c b/kernel/sched.c
index 5757e03cfac..196d48babbe 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4942,15 +4942,13 @@ pick_next_task(struct rq *rq)
/*
* schedule() is the main scheduler function.
*/
-asmlinkage void __sched schedule(void)
+asmlinkage void __sched __schedule(void)
{
struct task_struct *prev, *next;
unsigned long *switch_count;
struct rq *rq;
int cpu;
-need_resched:
- preempt_disable();
cpu = smp_processor_id();
rq = cpu_rq(cpu);
rcu_qsctr_inc(cpu);
@@ -5007,13 +5005,80 @@ need_resched_nonpreemptible:
if (unlikely(reacquire_kernel_lock(current) < 0))
goto need_resched_nonpreemptible;
+}
+asmlinkage void __sched schedule(void)
+{
+need_resched:
+ preempt_disable();
+ __schedule();
preempt_enable_no_resched();
if (unlikely(test_thread_flag(TIF_NEED_RESCHED)))
goto need_resched;
}
EXPORT_SYMBOL(schedule);
+#ifdef CONFIG_SMP
+/*
+ * Look out! "owner" is an entirely speculative pointer
+ * access and not reliable.
+ */
+int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner)
+{
+ unsigned int cpu;
+ struct rq *rq;
+
+ if (!sched_feat(OWNER_SPIN))
+ return 0;
+
+#ifdef CONFIG_DEBUG_PAGEALLOC
+ /*
+ * Need to access the cpu field knowing that
+ * DEBUG_PAGEALLOC could have unmapped it if
+ * the mutex owner just released it and exited.
+ */
+ if (probe_kernel_address(&owner->cpu, cpu))
+ goto out;
+#else
+ cpu = owner->cpu;
+#endif
+
+ /*
+ * Even if the access succeeded (likely case),
+ * the cpu field may no longer be valid.
+ */
+ if (cpu >= nr_cpumask_bits)
+ goto out;
+
+ /*
+ * We need to validate that we can do a
+ * get_cpu() and that we have the percpu area.
+ */
+ if (!cpu_online(cpu))
+ goto out;
+
+ rq = cpu_rq(cpu);
+
+ for (;;) {
+ /*
+ * Owner changed, break to re-assess state.
+ */
+ if (lock->owner != owner)
+ break;
+
+ /*
+ * Is that owner really running on that cpu?
+ */
+ if (task_thread_info(rq->curr) != owner || need_resched())
+ return 0;
+
+ cpu_relax();
+ }
+out:
+ return 1;
+}
+#endif
+
#ifdef CONFIG_PREEMPT
/*
* this is the entry point to schedule() from in-kernel preemption
diff --git a/kernel/sched_features.h b/kernel/sched_features.h
index 76f61756e67..4569bfa7df9 100644
--- a/kernel/sched_features.h
+++ b/kernel/sched_features.h
@@ -14,3 +14,4 @@ SCHED_FEAT(LB_WAKEUP_UPDATE, 1)
SCHED_FEAT(ASYM_EFF_LOAD, 1)
SCHED_FEAT(WAKEUP_OVERLAP, 0)
SCHED_FEAT(LAST_BUDDY, 1)
+SCHED_FEAT(OWNER_SPIN, 1)
diff --git a/kernel/timer.c b/kernel/timer.c
index 9b77fc9a9ac..b4555568b4e 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -491,14 +491,18 @@ static inline void debug_timer_free(struct timer_list *timer)
debug_object_free(timer, &timer_debug_descr);
}
-static void __init_timer(struct timer_list *timer);
+static void __init_timer(struct timer_list *timer,
+ const char *name,
+ struct lock_class_key *key);
-void init_timer_on_stack(struct timer_list *timer)
+void init_timer_on_stack_key(struct timer_list *timer,
+ const char *name,
+ struct lock_class_key *key)
{
debug_object_init_on_stack(timer, &timer_debug_descr);
- __init_timer(timer);
+ __init_timer(timer, name, key);
}
-EXPORT_SYMBOL_GPL(init_timer_on_stack);
+EXPORT_SYMBOL_GPL(init_timer_on_stack_key);
void destroy_timer_on_stack(struct timer_list *timer)
{
@@ -512,7 +516,9 @@ static inline void debug_timer_activate(struct timer_list *timer) { }
static inline void debug_timer_deactivate(struct timer_list *timer) { }
#endif
-static void __init_timer(struct timer_list *timer)
+static void __init_timer(struct timer_list *timer,
+ const char *name,
+ struct lock_class_key *key)
{
timer->entry.next = NULL;
timer->base = __raw_get_cpu_var(tvec_bases);
@@ -521,6 +527,7 @@ static void __init_timer(struct timer_list *timer)
timer->start_pid = -1;
memset(timer->start_comm, 0, TASK_COMM_LEN);
#endif
+ lockdep_init_map(&timer->lockdep_map, name, key, 0);
}
/**
@@ -530,19 +537,23 @@ static void __init_timer(struct timer_list *timer)
* init_timer() must be done to a timer prior calling *any* of the
* other timer functions.
*/
-void init_timer(struct timer_list *timer)
+void init_timer_key(struct timer_list *timer,
+ const char *name,
+ struct lock_class_key *key)
{
debug_timer_init(timer);
- __init_timer(timer);
+ __init_timer(timer, name, key);
}
-EXPORT_SYMBOL(init_timer);
+EXPORT_SYMBOL(init_timer_key);
-void init_timer_deferrable(struct timer_list *timer)
+void init_timer_deferrable_key(struct timer_list *timer,
+ const char *name,
+ struct lock_class_key *key)
{
- init_timer(timer);
+ init_timer_key(timer, name, key);
timer_set_deferrable(timer);
}
-EXPORT_SYMBOL(init_timer_deferrable);
+EXPORT_SYMBOL(init_timer_deferrable_key);
static inline void detach_timer(struct timer_list *timer,
int clear_pending)
@@ -826,6 +837,15 @@ EXPORT_SYMBOL(try_to_del_timer_sync);
*/
int del_timer_sync(struct timer_list *timer)
{
+#ifdef CONFIG_LOCKDEP
+ unsigned long flags;
+
+ local_irq_save(flags);
+ lock_map_acquire(&timer->lockdep_map);
+ lock_map_release(&timer->lockdep_map);
+ local_irq_restore(flags);
+#endif
+
for (;;) {
int ret = try_to_del_timer_sync(timer);
if (ret >= 0)
@@ -897,10 +917,36 @@ static inline void __run_timers(struct tvec_base *base)
set_running_timer(base, timer);
detach_timer(timer, 1);
+
spin_unlock_irq(&base->lock);
{
int preempt_count = preempt_count();
+
+#ifdef CONFIG_LOCKDEP
+ /*
+ * It is permissible to free the timer from
+ * inside the function that is called from
+ * it, this we need to take into account for
+ * lockdep too. To avoid bogus "held lock
+ * freed" warnings as well as problems when
+ * looking into timer->lockdep_map, make a
+ * copy and use that here.
+ */
+ struct lockdep_map lockdep_map =
+ timer->lockdep_map;
+#endif
+ /*
+ * Couple the lock chain with the lock chain at
+ * del_timer_sync() by acquiring the lock_map
+ * around the fn() call here and in
+ * del_timer_sync().
+ */
+ lock_map_acquire(&lockdep_map);
+
fn(data);
+
+ lock_map_release(&lockdep_map);
+
if (preempt_count != preempt_count()) {
printk(KERN_ERR "huh, entered %p "
"with preempt_count %08x, exited"
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-21 10:06:28 +0000