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Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 

* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  oprofile: warn on freeing event buffer too early
  oprofile: fix race condition in event_buffer free
  lockdep: Use cpu_clock() for lockstat
This commit is contained in:
Linus Torvalds 2009-10-14 15:25:35 -07:00
parent 220a6258b1 c7cedb125b
commit ee67e6cbe1
2 changed files with 38 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

35
drivers/oprofile/event_buffer.c
View File

@ -35,12 +35,23 @@ static size_t buffer_pos;
/* atomic_t because wait_event checks it outside of buffer_mutex */
static atomic_t buffer_ready = ATOMIC_INIT(0);
/* Add an entry to the event buffer. When we
* get near to the end we wake up the process
* sleeping on the read() of the file.
/*
* Add an entry to the event buffer. When we get near to the end we
* wake up the process sleeping on the read() of the file. To protect
* the event_buffer this function may only be called when buffer_mutex
* is set.
*/
void add_event_entry(unsigned long value)
{
/*
* This shouldn't happen since all workqueues or handlers are
* canceled or flushed before the event buffer is freed.
*/
if (!event_buffer) {
WARN_ON_ONCE(1);
return;
}
if (buffer_pos == buffer_size) {
atomic_inc(&oprofile_stats.event_lost_overflow);
return;
@ -69,7 +80,6 @@ void wake_up_buffer_waiter(void)
int alloc_event_buffer(void)
{
int err = -ENOMEM;
unsigned long flags;
spin_lock_irqsave(&oprofilefs_lock, flags);
@ -80,21 +90,22 @@ int alloc_event_buffer(void)
if (buffer_watershed >= buffer_size)
return -EINVAL;
buffer_pos = 0;
event_buffer = vmalloc(sizeof(unsigned long) * buffer_size);
if (!event_buffer)
goto out;
return -ENOMEM;
err = 0;
out:
return err;
return 0;
}
void free_event_buffer(void)
{
mutex_lock(&buffer_mutex);
vfree(event_buffer);
buffer_pos = 0;
event_buffer = NULL;
mutex_unlock(&buffer_mutex);
}
@ -167,6 +178,12 @@ static ssize_t event_buffer_read(struct file *file, char __user *buf,
mutex_lock(&buffer_mutex);
/* May happen if the buffer is freed during pending reads. */
if (!event_buffer) {
retval = -EINTR;
goto out;
}
atomic_set(&buffer_ready, 0);
retval = -EFAULT;

20
kernel/lockdep.c
View File

@ -142,6 +142,11 @@ static inline struct lock_class *hlock_class(struct held_lock *hlock)
#ifdef CONFIG_LOCK_STAT
static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS], lock_stats);
static inline u64 lockstat_clock(void)
{
return cpu_clock(smp_processor_id());
}
static int lock_point(unsigned long points[], unsigned long ip)
{
int i;
@ -158,7 +163,7 @@ static int lock_point(unsigned long points[], unsigned long ip)
return i;
}
static void lock_time_inc(struct lock_time *lt, s64 time)
static void lock_time_inc(struct lock_time *lt, u64 time)
{
if (time > lt->max)
lt->max = time;
@ -234,12 +239,12 @@ static void put_lock_stats(struct lock_class_stats *stats)
static void lock_release_holdtime(struct held_lock *hlock)
{
struct lock_class_stats *stats;
s64 holdtime;
u64 holdtime;
if (!lock_stat)
return;
holdtime = sched_clock() - hlock->holdtime_stamp;
holdtime = lockstat_clock() - hlock->holdtime_stamp;
stats = get_lock_stats(hlock_class(hlock));
if (hlock->read)
@ -2792,7 +2797,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
hlock->references = references;
#ifdef CONFIG_LOCK_STAT
hlock->waittime_stamp = 0;
hlock->holdtime_stamp = sched_clock();
hlock->holdtime_stamp = lockstat_clock();
#endif
if (check == 2 && !mark_irqflags(curr, hlock))
@ -3322,7 +3327,7 @@ found_it:
if (hlock->instance != lock)
return;
hlock->waittime_stamp = sched_clock();
hlock->waittime_stamp = lockstat_clock();
contention_point = lock_point(hlock_class(hlock)->contention_point, ip);
contending_point = lock_point(hlock_class(hlock)->contending_point,
@ -3345,8 +3350,7 @@ __lock_acquired(struct lockdep_map *lock, unsigned long ip)
struct held_lock *hlock, *prev_hlock;
struct lock_class_stats *stats;
unsigned int depth;
u64 now;
s64 waittime = 0;
u64 now, waittime = 0;
int i, cpu;
depth = curr->lockdep_depth;
@ -3374,7 +3378,7 @@ found_it:
cpu = smp_processor_id();
if (hlock->waittime_stamp) {
now = sched_clock();
now = lockstat_clock();
waittime = now - hlock->waittime_stamp;
hlock->holdtime_stamp = now;
}