[PATCH RT 14/25] kmemleak: Change the lock of kmemleak_object to raw_spinlock_t

From: zanussi
Date: Fri Feb 21 2020 - 16:26:26 EST


From: Liu Haitao <haitao.liu@xxxxxxxxxxxxx>

v4.14.170-rt75-rc1 stable review patch.
If anyone has any objections, please let me know.

-----------


[ Upstream commit 217847f57119b5fdd377bfa3d344613ddb98d9fc ]

The commit ("kmemleak: Turn kmemleak_lock to raw spinlock on RT")
changed the kmemleak_lock to raw spinlock. However the
kmemleak_object->lock is held after the kmemleak_lock is held in
scan_block().

Make the object->lock a raw_spinlock_t.

Cc: stable-rt@xxxxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/20190927082230.34152-1-yongxin.liu@xxxxxxxxxxxxx
Signed-off-by: Liu Haitao <haitao.liu@xxxxxxxxxxxxx>
Signed-off-by: Yongxin Liu <yongxin.liu@xxxxxxxxxxxxx>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Tom Zanussi <zanussi@xxxxxxxxxx>
---
mm/kmemleak.c | 72 +++++++++++++++++++++++++++++------------------------------
1 file changed, 36 insertions(+), 36 deletions(-)

diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index c18e23619f95..17718a11782b 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -148,7 +148,7 @@ struct kmemleak_scan_area {
* (use_count) and freed using the RCU mechanism.
*/
struct kmemleak_object {
- spinlock_t lock;
+ raw_spinlock_t lock;
unsigned int flags; /* object status flags */
struct list_head object_list;
struct list_head gray_list;
@@ -562,7 +562,7 @@ static struct kmemleak_object *create_object(unsigned long ptr, size_t size,
INIT_LIST_HEAD(&object->object_list);
INIT_LIST_HEAD(&object->gray_list);
INIT_HLIST_HEAD(&object->area_list);
- spin_lock_init(&object->lock);
+ raw_spin_lock_init(&object->lock);
atomic_set(&object->use_count, 1);
object->flags = OBJECT_ALLOCATED;
object->pointer = ptr;
@@ -643,9 +643,9 @@ static void __delete_object(struct kmemleak_object *object)
* Locking here also ensures that the corresponding memory block
* cannot be freed when it is being scanned.
*/
- spin_lock_irqsave(&object->lock, flags);
+ raw_spin_lock_irqsave(&object->lock, flags);
object->flags &= ~OBJECT_ALLOCATED;
- spin_unlock_irqrestore(&object->lock, flags);
+ raw_spin_unlock_irqrestore(&object->lock, flags);
put_object(object);
}

@@ -717,9 +717,9 @@ static void paint_it(struct kmemleak_object *object, int color)
{
unsigned long flags;

- spin_lock_irqsave(&object->lock, flags);
+ raw_spin_lock_irqsave(&object->lock, flags);
__paint_it(object, color);
- spin_unlock_irqrestore(&object->lock, flags);
+ raw_spin_unlock_irqrestore(&object->lock, flags);
}

static void paint_ptr(unsigned long ptr, int color)
@@ -779,7 +779,7 @@ static void add_scan_area(unsigned long ptr, size_t size, gfp_t gfp)
goto out;
}

- spin_lock_irqsave(&object->lock, flags);
+ raw_spin_lock_irqsave(&object->lock, flags);
if (size == SIZE_MAX) {
size = object->pointer + object->size - ptr;
} else if (ptr + size > object->pointer + object->size) {
@@ -795,7 +795,7 @@ static void add_scan_area(unsigned long ptr, size_t size, gfp_t gfp)

hlist_add_head(&area->node, &object->area_list);
out_unlock:
- spin_unlock_irqrestore(&object->lock, flags);
+ raw_spin_unlock_irqrestore(&object->lock, flags);
out:
put_object(object);
}
@@ -818,9 +818,9 @@ static void object_set_excess_ref(unsigned long ptr, unsigned long excess_ref)
return;
}

- spin_lock_irqsave(&object->lock, flags);
+ raw_spin_lock_irqsave(&object->lock, flags);
object->excess_ref = excess_ref;
- spin_unlock_irqrestore(&object->lock, flags);
+ raw_spin_unlock_irqrestore(&object->lock, flags);
put_object(object);
}

@@ -840,9 +840,9 @@ static void object_no_scan(unsigned long ptr)
return;
}

- spin_lock_irqsave(&object->lock, flags);
+ raw_spin_lock_irqsave(&object->lock, flags);
object->flags |= OBJECT_NO_SCAN;
- spin_unlock_irqrestore(&object->lock, flags);
+ raw_spin_unlock_irqrestore(&object->lock, flags);
put_object(object);
}

@@ -903,11 +903,11 @@ static void early_alloc(struct early_log *log)
log->min_count, GFP_ATOMIC);
if (!object)
goto out;
- spin_lock_irqsave(&object->lock, flags);
+ raw_spin_lock_irqsave(&object->lock, flags);
for (i = 0; i < log->trace_len; i++)
object->trace[i] = log->trace[i];
object->trace_len = log->trace_len;
- spin_unlock_irqrestore(&object->lock, flags);
+ raw_spin_unlock_irqrestore(&object->lock, flags);
out:
rcu_read_unlock();
}
@@ -1097,9 +1097,9 @@ void __ref kmemleak_update_trace(const void *ptr)
return;
}

- spin_lock_irqsave(&object->lock, flags);
+ raw_spin_lock_irqsave(&object->lock, flags);
object->trace_len = __save_stack_trace(object->trace);
- spin_unlock_irqrestore(&object->lock, flags);
+ raw_spin_unlock_irqrestore(&object->lock, flags);

put_object(object);
}
@@ -1335,7 +1335,7 @@ static void scan_block(void *_start, void *_end,
* previously acquired in scan_object(). These locks are
* enclosed by scan_mutex.
*/
- spin_lock_nested(&object->lock, SINGLE_DEPTH_NESTING);
+ raw_spin_lock_nested(&object->lock, SINGLE_DEPTH_NESTING);
/* only pass surplus references (object already gray) */
if (color_gray(object)) {
excess_ref = object->excess_ref;
@@ -1344,7 +1344,7 @@ static void scan_block(void *_start, void *_end,
excess_ref = 0;
update_refs(object);
}
- spin_unlock(&object->lock);
+ raw_spin_unlock(&object->lock);

if (excess_ref) {
object = lookup_object(excess_ref, 0);
@@ -1353,9 +1353,9 @@ static void scan_block(void *_start, void *_end,
if (object == scanned)
/* circular reference, ignore */
continue;
- spin_lock_nested(&object->lock, SINGLE_DEPTH_NESTING);
+ raw_spin_lock_nested(&object->lock, SINGLE_DEPTH_NESTING);
update_refs(object);
- spin_unlock(&object->lock);
+ raw_spin_unlock(&object->lock);
}
}
raw_spin_unlock_irqrestore(&kmemleak_lock, flags);
@@ -1391,7 +1391,7 @@ static void scan_object(struct kmemleak_object *object)
* Once the object->lock is acquired, the corresponding memory block
* cannot be freed (the same lock is acquired in delete_object).
*/
- spin_lock_irqsave(&object->lock, flags);
+ raw_spin_lock_irqsave(&object->lock, flags);
if (object->flags & OBJECT_NO_SCAN)
goto out;
if (!(object->flags & OBJECT_ALLOCATED))
@@ -1410,9 +1410,9 @@ static void scan_object(struct kmemleak_object *object)
if (start >= end)
break;

- spin_unlock_irqrestore(&object->lock, flags);
+ raw_spin_unlock_irqrestore(&object->lock, flags);
cond_resched();
- spin_lock_irqsave(&object->lock, flags);
+ raw_spin_lock_irqsave(&object->lock, flags);
} while (object->flags & OBJECT_ALLOCATED);
} else
hlist_for_each_entry(area, &object->area_list, node)
@@ -1420,7 +1420,7 @@ static void scan_object(struct kmemleak_object *object)
(void *)(area->start + area->size),
object);
out:
- spin_unlock_irqrestore(&object->lock, flags);
+ raw_spin_unlock_irqrestore(&object->lock, flags);
}

/*
@@ -1473,7 +1473,7 @@ static void kmemleak_scan(void)
/* prepare the kmemleak_object's */
rcu_read_lock();
list_for_each_entry_rcu(object, &object_list, object_list) {
- spin_lock_irqsave(&object->lock, flags);
+ raw_spin_lock_irqsave(&object->lock, flags);
#ifdef DEBUG
/*
* With a few exceptions there should be a maximum of
@@ -1490,7 +1490,7 @@ static void kmemleak_scan(void)
if (color_gray(object) && get_object(object))
list_add_tail(&object->gray_list, &gray_list);

- spin_unlock_irqrestore(&object->lock, flags);
+ raw_spin_unlock_irqrestore(&object->lock, flags);
}
rcu_read_unlock();

@@ -1555,14 +1555,14 @@ static void kmemleak_scan(void)
*/
rcu_read_lock();
list_for_each_entry_rcu(object, &object_list, object_list) {
- spin_lock_irqsave(&object->lock, flags);
+ raw_spin_lock_irqsave(&object->lock, flags);
if (color_white(object) && (object->flags & OBJECT_ALLOCATED)
&& update_checksum(object) && get_object(object)) {
/* color it gray temporarily */
object->count = object->min_count;
list_add_tail(&object->gray_list, &gray_list);
}
- spin_unlock_irqrestore(&object->lock, flags);
+ raw_spin_unlock_irqrestore(&object->lock, flags);
}
rcu_read_unlock();

@@ -1582,13 +1582,13 @@ static void kmemleak_scan(void)
*/
rcu_read_lock();
list_for_each_entry_rcu(object, &object_list, object_list) {
- spin_lock_irqsave(&object->lock, flags);
+ raw_spin_lock_irqsave(&object->lock, flags);
if (unreferenced_object(object) &&
!(object->flags & OBJECT_REPORTED)) {
object->flags |= OBJECT_REPORTED;
new_leaks++;
}
- spin_unlock_irqrestore(&object->lock, flags);
+ raw_spin_unlock_irqrestore(&object->lock, flags);
}
rcu_read_unlock();

@@ -1740,10 +1740,10 @@ static int kmemleak_seq_show(struct seq_file *seq, void *v)
struct kmemleak_object *object = v;
unsigned long flags;

- spin_lock_irqsave(&object->lock, flags);
+ raw_spin_lock_irqsave(&object->lock, flags);
if ((object->flags & OBJECT_REPORTED) && unreferenced_object(object))
print_unreferenced(seq, object);
- spin_unlock_irqrestore(&object->lock, flags);
+ raw_spin_unlock_irqrestore(&object->lock, flags);
return 0;
}

@@ -1773,9 +1773,9 @@ static int dump_str_object_info(const char *str)
return -EINVAL;
}

- spin_lock_irqsave(&object->lock, flags);
+ raw_spin_lock_irqsave(&object->lock, flags);
dump_object_info(object);
- spin_unlock_irqrestore(&object->lock, flags);
+ raw_spin_unlock_irqrestore(&object->lock, flags);

put_object(object);
return 0;
@@ -1794,11 +1794,11 @@ static void kmemleak_clear(void)

rcu_read_lock();
list_for_each_entry_rcu(object, &object_list, object_list) {
- spin_lock_irqsave(&object->lock, flags);
+ raw_spin_lock_irqsave(&object->lock, flags);
if ((object->flags & OBJECT_REPORTED) &&
unreferenced_object(object))
__paint_it(object, KMEMLEAK_GREY);
- spin_unlock_irqrestore(&object->lock, flags);
+ raw_spin_unlock_irqrestore(&object->lock, flags);
}
rcu_read_unlock();

--
2.14.1