[git pull] core/locking for v2.6.27

From: Ingo Molnar
Date: Mon Jul 14 2008 - 10:33:18 EST

Linus,

Please pull the latest core/locking git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git core/locking

Thanks,

Ingo

------------------>
Huang, Ying (3):
lockdep: output lock_class key instead of address for forward dependency output
lockdep: add lock_class information to lock_chain and output it
lockdep: add lock_class information to lock_chain and output it

Ingo Molnar (2):
lockdep: fix ftrace irq tracing false positive
lockdep: fix kernel/fork.c warning

Jeremy Kerr (1):
mutex-debug: check mutex magic before owner

Li Zefan (1):
lockdep: remove duplicate definition of STATIC_LOCKDEP_MAP_INIT

Oleg Nesterov (1):
__mutex_lock_common: use signal_pending_state()


include/linux/lockdep.h | 11 +----
kernel/fork.c | 2 +-
kernel/lockdep.c | 47 +++++++++++++++++++--
kernel/lockdep_internals.h | 6 +++
kernel/lockdep_proc.c | 97 +++++++++++++++++++++++++++++++++++++++++++-
kernel/mutex-debug.c | 2 +-
kernel/mutex.c | 5 +--
7 files changed, 151 insertions(+), 19 deletions(-)

diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 4c4d236..2486eb4 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -182,6 +182,9 @@ struct lock_list {
* We record lock dependency chains, so that we can cache them:
*/
struct lock_chain {
+ u8 irq_context;
+ u8 depth;
+ u16 base;
struct list_head entry;
u64 chain_key;
};
@@ -276,14 +279,6 @@ extern void lockdep_init_map(struct lockdep_map *lock, const char *name,
(lock)->dep_map.key, sub)

/*
- * To initialize a lockdep_map statically use this macro.
- * Note that _name must not be NULL.
- */
-#define STATIC_LOCKDEP_MAP_INIT(_name, _key) \
- { .name = (_name), .key = (void *)(_key), }
-
-
-/*
* Acquire a lock.
*
* Values for "read":
diff --git a/kernel/fork.c b/kernel/fork.c
index 19908b2..cdb1f82 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -909,7 +909,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,

rt_mutex_init_task(p);

-#ifdef CONFIG_TRACE_IRQFLAGS
+#ifdef CONFIG_PROVE_LOCKING
DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled);
DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled);
#endif
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 81a4e4a..fc5d5aa 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -1458,7 +1458,14 @@ out_bug:
}

unsigned long nr_lock_chains;
-static struct lock_chain lock_chains[MAX_LOCKDEP_CHAINS];
+struct lock_chain lock_chains[MAX_LOCKDEP_CHAINS];
+int nr_chain_hlocks;
+static u16 chain_hlocks[MAX_LOCKDEP_CHAIN_HLOCKS];
+
+struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i)
+{
+ return lock_classes + chain_hlocks[chain->base + i];
+}

/*
* Look up a dependency chain. If the key is not present yet then
@@ -1466,10 +1473,15 @@ static struct lock_chain lock_chains[MAX_LOCKDEP_CHAINS];
* validated. If the key is already hashed, return 0.
* (On return with 1 graph_lock is held.)
*/
-static inline int lookup_chain_cache(u64 chain_key, struct lock_class *class)
+static inline int lookup_chain_cache(struct task_struct *curr,
+ struct held_lock *hlock,
+ u64 chain_key)
{
+ struct lock_class *class = hlock->class;
struct list_head *hash_head = chainhashentry(chain_key);
struct lock_chain *chain;
+ struct held_lock *hlock_curr, *hlock_next;
+ int i, j, n, cn;

if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
return 0;
@@ -1517,6 +1529,32 @@ cache_hit:
}
chain = lock_chains + nr_lock_chains++;
chain->chain_key = chain_key;
+ chain->irq_context = hlock->irq_context;
+ /* Find the first held_lock of current chain */
+ hlock_next = hlock;
+ for (i = curr->lockdep_depth - 1; i >= 0; i--) {
+ hlock_curr = curr->held_locks + i;
+ if (hlock_curr->irq_context != hlock_next->irq_context)
+ break;
+ hlock_next = hlock;
+ }
+ i++;
+ chain->depth = curr->lockdep_depth + 1 - i;
+ cn = nr_chain_hlocks;
+ while (cn + chain->depth <= MAX_LOCKDEP_CHAIN_HLOCKS) {
+ n = cmpxchg(&nr_chain_hlocks, cn, cn + chain->depth);
+ if (n == cn)
+ break;
+ cn = n;
+ }
+ if (likely(cn + chain->depth <= MAX_LOCKDEP_CHAIN_HLOCKS)) {
+ chain->base = cn;
+ for (j = 0; j < chain->depth - 1; j++, i++) {
+ int lock_id = curr->held_locks[i].class - lock_classes;
+ chain_hlocks[chain->base + j] = lock_id;
+ }
+ chain_hlocks[chain->base + j] = class - lock_classes;
+ }
list_add_tail_rcu(&chain->entry, hash_head);
debug_atomic_inc(&chain_lookup_misses);
inc_chains();
@@ -1538,7 +1576,7 @@ static int validate_chain(struct task_struct *curr, struct lockdep_map *lock,
* graph_lock for us)
*/
if (!hlock->trylock && (hlock->check == 2) &&
- lookup_chain_cache(chain_key, hlock->class)) {
+ lookup_chain_cache(curr, hlock, chain_key)) {
/*
* Check whether last held lock:
*
@@ -2650,7 +2688,8 @@ __lock_release(struct lockdep_map *lock, int nested, unsigned long ip)
*/
static void check_flags(unsigned long flags)
{
-#if defined(CONFIG_DEBUG_LOCKDEP) && defined(CONFIG_TRACE_IRQFLAGS)
+#if defined(CONFIG_PROVE_LOCKING) && defined(CONFIG_DEBUG_LOCKDEP) && \
+ defined(CONFIG_TRACE_IRQFLAGS)
if (!debug_locks)
return;

diff --git a/kernel/lockdep_internals.h b/kernel/lockdep_internals.h
index 8ce09bc..c3600a0 100644
--- a/kernel/lockdep_internals.h
+++ b/kernel/lockdep_internals.h
@@ -23,6 +23,8 @@
#define MAX_LOCKDEP_CHAINS_BITS 14
#define MAX_LOCKDEP_CHAINS (1UL << MAX_LOCKDEP_CHAINS_BITS)

+#define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS*5)
+
/*
* Stack-trace: tightly packed array of stack backtrace
* addresses. Protected by the hash_lock.
@@ -30,15 +32,19 @@
#define MAX_STACK_TRACE_ENTRIES 262144UL

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);

extern const char * __get_key_name(struct lockdep_subclass_key *key, char *str);

+struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i);
+
extern unsigned long nr_lock_classes;
extern unsigned long nr_list_entries;
extern unsigned long nr_lock_chains;
+extern int nr_chain_hlocks;
extern unsigned long nr_stack_trace_entries;

extern unsigned int nr_hardirq_chains;
diff --git a/kernel/lockdep_proc.c b/kernel/lockdep_proc.c
index dc5d296..9b0e940 100644
--- a/kernel/lockdep_proc.c
+++ b/kernel/lockdep_proc.c
@@ -139,7 +139,7 @@ static int l_show(struct seq_file *m, void *v)

list_for_each_entry(entry, &class->locks_after, entry) {
if (entry->distance == 1) {
- seq_printf(m, " -> [%p] ", entry->class);
+ seq_printf(m, " -> [%p] ", entry->class->key);
print_name(m, entry->class);
seq_puts(m, "\n");
}
@@ -178,6 +178,95 @@ static const struct file_operations proc_lockdep_operations = {
.release = seq_release,
};

+#ifdef CONFIG_PROVE_LOCKING
+static void *lc_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ struct lock_chain *chain;
+
+ (*pos)++;
+
+ if (v == SEQ_START_TOKEN)
+ chain = m->private;
+ else {
+ chain = v;
+
+ if (*pos < nr_lock_chains)
+ chain = lock_chains + *pos;
+ else
+ chain = NULL;
+ }
+
+ return chain;
+}
+
+static void *lc_start(struct seq_file *m, loff_t *pos)
+{
+ if (*pos == 0)
+ return SEQ_START_TOKEN;
+
+ if (*pos < nr_lock_chains)
+ return lock_chains + *pos;
+
+ return NULL;
+}
+
+static void lc_stop(struct seq_file *m, void *v)
+{
+}
+
+static int lc_show(struct seq_file *m, void *v)
+{
+ struct lock_chain *chain = v;
+ struct lock_class *class;
+ int i;
+
+ if (v == SEQ_START_TOKEN) {
+ seq_printf(m, "all lock chains:\n");
+ return 0;
+ }
+
+ seq_printf(m, "irq_context: %d\n", chain->irq_context);
+
+ for (i = 0; i < chain->depth; i++) {
+ class = lock_chain_get_class(chain, i);
+ seq_printf(m, "[%p] ", class->key);
+ print_name(m, class);
+ seq_puts(m, "\n");
+ }
+ seq_puts(m, "\n");
+
+ return 0;
+}
+
+static const struct seq_operations lockdep_chains_ops = {
+ .start = lc_start,
+ .next = lc_next,
+ .stop = lc_stop,
+ .show = lc_show,
+};
+
+static int lockdep_chains_open(struct inode *inode, struct file *file)
+{
+ int res = seq_open(file, &lockdep_chains_ops);
+ if (!res) {
+ struct seq_file *m = file->private_data;
+
+ if (nr_lock_chains)
+ m->private = lock_chains;
+ else
+ m->private = NULL;
+ }
+ return res;
+}
+
+static const struct file_operations proc_lockdep_chains_operations = {
+ .open = lockdep_chains_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+#endif /* CONFIG_PROVE_LOCKING */
+
static void lockdep_stats_debug_show(struct seq_file *m)
{
#ifdef CONFIG_DEBUG_LOCKDEP
@@ -294,6 +383,8 @@ static int lockdep_stats_show(struct seq_file *m, void *v)
#ifdef CONFIG_PROVE_LOCKING
seq_printf(m, " dependency chains: %11lu [max: %lu]\n",
nr_lock_chains, MAX_LOCKDEP_CHAINS);
+ seq_printf(m, " dependency chain hlocks: %11d [max: %lu]\n",
+ nr_chain_hlocks, MAX_LOCKDEP_CHAIN_HLOCKS);
#endif

#ifdef CONFIG_TRACE_IRQFLAGS
@@ -661,6 +752,10 @@ static const struct file_operations proc_lock_stat_operations = {
static int __init lockdep_proc_init(void)
{
proc_create("lockdep", S_IRUSR, NULL, &proc_lockdep_operations);
+#ifdef CONFIG_PROVE_LOCKING
+ proc_create("lockdep_chains", S_IRUSR, NULL,
+ &proc_lockdep_chains_operations);
+#endif
proc_create("lockdep_stats", S_IRUSR, NULL,
&proc_lockdep_stats_operations);

diff --git a/kernel/mutex-debug.c b/kernel/mutex-debug.c
index 3aaa06c..1d94160 100644
--- a/kernel/mutex-debug.c
+++ b/kernel/mutex-debug.c
@@ -79,8 +79,8 @@ void debug_mutex_unlock(struct mutex *lock)
if (unlikely(!debug_locks))
return;

- DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info());
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());
}
diff --git a/kernel/mutex.c b/kernel/mutex.c
index d046a34..bcdc9ac 100644
--- a/kernel/mutex.c
+++ b/kernel/mutex.c
@@ -165,10 +165,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
* got a signal? (This code gets eliminated in the
* TASK_UNINTERRUPTIBLE case.)
*/
- if (unlikely((state == TASK_INTERRUPTIBLE &&
- signal_pending(task)) ||
- (state == TASK_KILLABLE &&
- fatal_signal_pending(task)))) {
+ if (unlikely(signal_pending_state(state, task))) {
mutex_remove_waiter(lock, &waiter,
task_thread_info(task));
mutex_release(&lock->dep_map, 1, ip);
--
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