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-rw-r--r--mm/kmemleak.c64
1 files changed, 52 insertions, 12 deletions
diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 576c0a4cec52..8172154502a6 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -229,6 +229,8 @@ struct early_log {
int min_count; /* minimum reference count */
unsigned long offset; /* scan area offset */
size_t length; /* scan area length */
+ unsigned long trace[MAX_TRACE]; /* stack trace */
+ unsigned int trace_len; /* stack trace length */
};
/* early logging buffer and current position */
@@ -437,21 +439,36 @@ static struct kmemleak_object *find_and_get_object(unsigned long ptr, int alias)
}
/*
+ * Save stack trace to the given array of MAX_TRACE size.
+ */
+static int __save_stack_trace(unsigned long *trace)
+{
+ struct stack_trace stack_trace;
+
+ stack_trace.max_entries = MAX_TRACE;
+ stack_trace.nr_entries = 0;
+ stack_trace.entries = trace;
+ stack_trace.skip = 2;
+ save_stack_trace(&stack_trace);
+
+ return stack_trace.nr_entries;
+}
+
+/*
* Create the metadata (struct kmemleak_object) corresponding to an allocated
* memory block and add it to the object_list and object_tree_root.
*/
-static void create_object(unsigned long ptr, size_t size, int min_count,
- gfp_t gfp)
+static struct kmemleak_object *create_object(unsigned long ptr, size_t size,
+ int min_count, gfp_t gfp)
{
unsigned long flags;
struct kmemleak_object *object;
struct prio_tree_node *node;
- struct stack_trace trace;
object = kmem_cache_alloc(object_cache, gfp & GFP_KMEMLEAK_MASK);
if (!object) {
kmemleak_stop("Cannot allocate a kmemleak_object structure\n");
- return;
+ return NULL;
}
INIT_LIST_HEAD(&object->object_list);
@@ -485,12 +502,7 @@ static void create_object(unsigned long ptr, size_t size, int min_count,
}
/* kernel backtrace */
- trace.max_entries = MAX_TRACE;
- trace.nr_entries = 0;
- trace.entries = object->trace;
- trace.skip = 1;
- save_stack_trace(&trace);
- object->trace_len = trace.nr_entries;
+ object->trace_len = __save_stack_trace(object->trace);
INIT_PRIO_TREE_NODE(&object->tree_node);
object->tree_node.start = ptr;
@@ -521,6 +533,7 @@ static void create_object(unsigned long ptr, size_t size, int min_count,
list_add_tail_rcu(&object->object_list, &object_list);
out:
write_unlock_irqrestore(&kmemleak_lock, flags);
+ return object;
}
/*
@@ -743,11 +756,39 @@ static void __init log_early(int op_type, const void *ptr, size_t size,
log->min_count = min_count;
log->offset = offset;
log->length = length;
+ if (op_type == KMEMLEAK_ALLOC)
+ log->trace_len = __save_stack_trace(log->trace);
crt_early_log++;
local_irq_restore(flags);
}
/*
+ * Log an early allocated block and populate the stack trace.
+ */
+static void early_alloc(struct early_log *log)
+{
+ struct kmemleak_object *object;
+ unsigned long flags;
+ int i;
+
+ if (!atomic_read(&kmemleak_enabled) || !log->ptr || IS_ERR(log->ptr))
+ return;
+
+ /*
+ * RCU locking needed to ensure object is not freed via put_object().
+ */
+ rcu_read_lock();
+ object = create_object((unsigned long)log->ptr, log->size,
+ log->min_count, GFP_KERNEL);
+ 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);
+ rcu_read_unlock();
+}
+
+/*
* Memory allocation function callback. This function is called from the
* kernel allocators when a new block is allocated (kmem_cache_alloc, kmalloc,
* vmalloc etc.).
@@ -1509,8 +1550,7 @@ void __init kmemleak_init(void)
switch (log->op_type) {
case KMEMLEAK_ALLOC:
- kmemleak_alloc(log->ptr, log->size, log->min_count,
- GFP_KERNEL);
+ early_alloc(log);
break;
case KMEMLEAK_FREE:
kmemleak_free(log->ptr);