#include <linux/sched.h>
#include <linux/jiffies.h>
#include <linux/delay.h>
-#include <linux/module.h>
+#include <linux/export.h>
#include <linux/kthread.h>
#include <linux/prio_tree.h>
#include <linux/fs.h>
#include <asm/sections.h>
#include <asm/processor.h>
-#include <asm/atomic.h>
+#include <linux/atomic.h>
#include <linux/kmemcheck.h>
#include <linux/kmemleak.h>
+#include <linux/memory_hotplug.h>
/*
* Kmemleak configuration and common defines.
#define BYTES_PER_POINTER sizeof(void *)
/* GFP bitmask for kmemleak internal allocations */
-#define GFP_KMEMLEAK_MASK (GFP_KERNEL | GFP_ATOMIC)
+#define gfp_kmemleak_mask(gfp) (((gfp) & (GFP_KERNEL | GFP_ATOMIC)) | \
+ __GFP_NORETRY | __GFP_NOMEMALLOC | \
+ __GFP_NOWARN)
/* scanning area inside a memory block */
struct kmemleak_scan_area {
static atomic_t kmemleak_initialized = ATOMIC_INIT(0);
/* enables or disables early logging of the memory operations */
static atomic_t kmemleak_early_log = ATOMIC_INIT(1);
-/* set if a fata kmemleak error has occurred */
+/* set if a kmemleak warning was issued */
+static atomic_t kmemleak_warning = ATOMIC_INIT(0);
+/* set if a fatal kmemleak error has occurred */
static atomic_t kmemleak_error = ATOMIC_INIT(0);
/* minimum and maximum address that may be valid pointers */
/* kmemleak operation type for early logging */
enum {
KMEMLEAK_ALLOC,
+ KMEMLEAK_ALLOC_PERCPU,
KMEMLEAK_FREE,
KMEMLEAK_FREE_PART,
+ KMEMLEAK_FREE_PERCPU,
KMEMLEAK_NOT_LEAK,
KMEMLEAK_IGNORE,
KMEMLEAK_SCAN_AREA,
/*
* Print a warning and dump the stack trace.
*/
-#define kmemleak_warn(x...) do { \
- pr_warning(x); \
- dump_stack(); \
+#define kmemleak_warn(x...) do { \
+ pr_warning(x); \
+ dump_stack(); \
+ atomic_set(&kmemleak_warning, 1); \
} while (0)
/*
- * Macro invoked when a serious kmemleak condition occured and cannot be
+ * Macro invoked when a serious kmemleak condition occurred and cannot be
* recovered from. Kmemleak will be disabled and further allocation/freeing
* tracing no longer available.
*/
object = prio_tree_entry(node, struct kmemleak_object,
tree_node);
if (!alias && object->pointer != ptr) {
- pr_warning("Found object by alias at 0x%08lx\n", ptr);
- dump_stack();
+ kmemleak_warn("Found object by alias at 0x%08lx\n",
+ ptr);
dump_object_info(object);
object = NULL;
}
struct kmemleak_object *object;
struct prio_tree_node *node;
- object = kmem_cache_alloc(object_cache, gfp & GFP_KMEMLEAK_MASK);
+ object = kmem_cache_alloc(object_cache, gfp_kmemleak_mask(gfp));
if (!object) {
- kmemleak_stop("Cannot allocate a kmemleak_object structure\n");
+ pr_warning("Cannot allocate a kmemleak_object structure\n");
+ kmemleak_disable();
return NULL;
}
}
/*
- * Make a object permanently as gray-colored so that it can no longer be
+ * Mark an object permanently as gray-colored so that it can no longer be
* reported as a leak. This is used in general to mark a false positive.
*/
static void make_gray_object(unsigned long ptr)
return;
}
- area = kmem_cache_alloc(scan_area_cache, gfp & GFP_KMEMLEAK_MASK);
+ area = kmem_cache_alloc(scan_area_cache, gfp_kmemleak_mask(gfp));
if (!area) {
- kmemleak_warn("Cannot allocate a scan area\n");
+ pr_warning("Cannot allocate a scan area\n");
goto out;
}
unsigned long flags;
struct early_log *log;
+ if (atomic_read(&kmemleak_error)) {
+ /* kmemleak stopped recording, just count the requests */
+ crt_early_log++;
+ return;
+ }
+
if (crt_early_log >= ARRAY_SIZE(early_log)) {
- pr_warning("Early log buffer exceeded, "
- "please increase DEBUG_KMEMLEAK_EARLY_LOG_SIZE\n");
kmemleak_disable();
return;
}
log->ptr = ptr;
log->size = size;
log->min_count = min_count;
- if (op_type == KMEMLEAK_ALLOC)
- log->trace_len = __save_stack_trace(log->trace);
+ log->trace_len = __save_stack_trace(log->trace);
crt_early_log++;
local_irq_restore(flags);
}
}
/*
- * Memory allocation function callback. This function is called from the
- * kernel allocators when a new block is allocated (kmem_cache_alloc, kmalloc,
- * vmalloc etc.).
+ * Log an early allocated block and populate the stack trace.
+ */
+static void early_alloc_percpu(struct early_log *log)
+{
+ unsigned int cpu;
+ const void __percpu *ptr = log->ptr;
+
+ for_each_possible_cpu(cpu) {
+ log->ptr = per_cpu_ptr(ptr, cpu);
+ early_alloc(log);
+ }
+}
+
+/**
+ * kmemleak_alloc - register a newly allocated object
+ * @ptr: pointer to beginning of the object
+ * @size: size of the object
+ * @min_count: minimum number of references to this object. If during memory
+ * scanning a number of references less than @min_count is found,
+ * the object is reported as a memory leak. If @min_count is 0,
+ * the object is never reported as a leak. If @min_count is -1,
+ * the object is ignored (not scanned and not reported as a leak)
+ * @gfp: kmalloc() flags used for kmemleak internal memory allocations
+ *
+ * This function is called from the kernel allocators when a new object
+ * (memory block) is allocated (kmem_cache_alloc, kmalloc, vmalloc etc.).
*/
void __ref kmemleak_alloc(const void *ptr, size_t size, int min_count,
gfp_t gfp)
}
EXPORT_SYMBOL_GPL(kmemleak_alloc);
-/*
- * Memory freeing function callback. This function is called from the kernel
- * allocators when a block is freed (kmem_cache_free, kfree, vfree etc.).
+/**
+ * kmemleak_alloc_percpu - register a newly allocated __percpu object
+ * @ptr: __percpu pointer to beginning of the object
+ * @size: size of the object
+ *
+ * This function is called from the kernel percpu allocator when a new object
+ * (memory block) is allocated (alloc_percpu). It assumes GFP_KERNEL
+ * allocation.
+ */
+void __ref kmemleak_alloc_percpu(const void __percpu *ptr, size_t size)
+{
+ unsigned int cpu;
+
+ pr_debug("%s(0x%p, %zu)\n", __func__, ptr, size);
+
+ /*
+ * Percpu allocations are only scanned and not reported as leaks
+ * (min_count is set to 0).
+ */
+ if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
+ for_each_possible_cpu(cpu)
+ create_object((unsigned long)per_cpu_ptr(ptr, cpu),
+ size, 0, GFP_KERNEL);
+ else if (atomic_read(&kmemleak_early_log))
+ log_early(KMEMLEAK_ALLOC_PERCPU, ptr, size, 0);
+}
+EXPORT_SYMBOL_GPL(kmemleak_alloc_percpu);
+
+/**
+ * kmemleak_free - unregister a previously registered object
+ * @ptr: pointer to beginning of the object
+ *
+ * This function is called from the kernel allocators when an object (memory
+ * block) is freed (kmem_cache_free, kfree, vfree etc.).
*/
void __ref kmemleak_free(const void *ptr)
{
}
EXPORT_SYMBOL_GPL(kmemleak_free);
-/*
- * Partial memory freeing function callback. This function is usually called
- * from bootmem allocator when (part of) a memory block is freed.
+/**
+ * kmemleak_free_part - partially unregister a previously registered object
+ * @ptr: pointer to the beginning or inside the object. This also
+ * represents the start of the range to be freed
+ * @size: size to be unregistered
+ *
+ * This function is called when only a part of a memory block is freed
+ * (usually from the bootmem allocator).
*/
void __ref kmemleak_free_part(const void *ptr, size_t size)
{
}
EXPORT_SYMBOL_GPL(kmemleak_free_part);
-/*
- * Mark an already allocated memory block as a false positive. This will cause
- * the block to no longer be reported as leak and always be scanned.
+/**
+ * kmemleak_free_percpu - unregister a previously registered __percpu object
+ * @ptr: __percpu pointer to beginning of the object
+ *
+ * This function is called from the kernel percpu allocator when an object
+ * (memory block) is freed (free_percpu).
+ */
+void __ref kmemleak_free_percpu(const void __percpu *ptr)
+{
+ unsigned int cpu;
+
+ pr_debug("%s(0x%p)\n", __func__, ptr);
+
+ if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
+ for_each_possible_cpu(cpu)
+ delete_object_full((unsigned long)per_cpu_ptr(ptr,
+ cpu));
+ else if (atomic_read(&kmemleak_early_log))
+ log_early(KMEMLEAK_FREE_PERCPU, ptr, 0, 0);
+}
+EXPORT_SYMBOL_GPL(kmemleak_free_percpu);
+
+/**
+ * kmemleak_not_leak - mark an allocated object as false positive
+ * @ptr: pointer to beginning of the object
+ *
+ * Calling this function on an object will cause the memory block to no longer
+ * be reported as leak and always be scanned.
*/
void __ref kmemleak_not_leak(const void *ptr)
{
}
EXPORT_SYMBOL(kmemleak_not_leak);
-/*
- * Ignore a memory block. This is usually done when it is known that the
- * corresponding block is not a leak and does not contain any references to
- * other allocated memory blocks.
+/**
+ * kmemleak_ignore - ignore an allocated object
+ * @ptr: pointer to beginning of the object
+ *
+ * Calling this function on an object will cause the memory block to be
+ * ignored (not scanned and not reported as a leak). This is usually done when
+ * it is known that the corresponding block is not a leak and does not contain
+ * any references to other allocated memory blocks.
*/
void __ref kmemleak_ignore(const void *ptr)
{
}
EXPORT_SYMBOL(kmemleak_ignore);
-/*
- * Limit the range to be scanned in an allocated memory block.
+/**
+ * kmemleak_scan_area - limit the range to be scanned in an allocated object
+ * @ptr: pointer to beginning or inside the object. This also
+ * represents the start of the scan area
+ * @size: size of the scan area
+ * @gfp: kmalloc() flags used for kmemleak internal memory allocations
+ *
+ * This function is used when it is known that only certain parts of an object
+ * contain references to other objects. Kmemleak will only scan these areas
+ * reducing the number false negatives.
*/
void __ref kmemleak_scan_area(const void *ptr, size_t size, gfp_t gfp)
{
pr_debug("%s(0x%p)\n", __func__, ptr);
- if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
+ if (atomic_read(&kmemleak_enabled) && ptr && size && !IS_ERR(ptr))
add_scan_area((unsigned long)ptr, size, gfp);
else if (atomic_read(&kmemleak_early_log))
log_early(KMEMLEAK_SCAN_AREA, ptr, size, 0);
}
EXPORT_SYMBOL(kmemleak_scan_area);
-/*
- * Inform kmemleak not to scan the given memory block.
+/**
+ * kmemleak_no_scan - do not scan an allocated object
+ * @ptr: pointer to beginning of the object
+ *
+ * This function notifies kmemleak not to scan the given memory block. Useful
+ * in situations where it is known that the given object does not contain any
+ * references to other objects. Kmemleak will not scan such objects reducing
+ * the number of false negatives.
*/
void __ref kmemleak_no_scan(const void *ptr)
{
/*
* Memory scanning is a long process and it needs to be interruptable. This
- * function checks whether such interrupt condition occured.
+ * function checks whether such interrupt condition occurred.
*/
static int scan_should_stop(void)
{
#endif
/*
- * Struct page scanning for each node. The code below is not yet safe
- * with MEMORY_HOTPLUG.
+ * Struct page scanning for each node.
*/
+ lock_memory_hotplug();
for_each_online_node(i) {
pg_data_t *pgdat = NODE_DATA(i);
unsigned long start_pfn = pgdat->node_start_pfn;
scan_block(page, page + 1, NULL, 1);
}
}
+ unlock_memory_hotplug();
/*
* Scanning the task stacks (may introduce false negatives).
++(*pos);
list_for_each_continue_rcu(n, &object_list) {
- next_obj = list_entry(n, struct kmemleak_object, object_list);
- if (get_object(next_obj))
+ struct kmemleak_object *obj =
+ list_entry(n, struct kmemleak_object, object_list);
+ if (get_object(obj)) {
+ next_obj = obj;
break;
+ }
}
put_object(prev_obj);
static int kmemleak_open(struct inode *inode, struct file *file)
{
- if (!atomic_read(&kmemleak_enabled))
- return -EBUSY;
-
return seq_open(file, &kmemleak_seq_ops);
}
int buf_size;
int ret;
+ if (!atomic_read(&kmemleak_enabled))
+ return -EBUSY;
+
buf_size = min(size, (sizeof(buf) - 1));
if (strncpy_from_user(buf, user_buf, buf_size) < 0)
return -EFAULT;
};
/*
- * Perform the freeing of the kmemleak internal objects after waiting for any
- * current memory scan to complete.
+ * Stop the memory scanning thread and free the kmemleak internal objects if
+ * no previous scan thread (otherwise, kmemleak may still have some useful
+ * information on memory leaks).
*/
static void kmemleak_do_cleanup(struct work_struct *work)
{
struct kmemleak_object *object;
+ bool cleanup = scan_thread == NULL;
mutex_lock(&scan_mutex);
stop_scan_thread();
- rcu_read_lock();
- list_for_each_entry_rcu(object, &object_list, object_list)
- delete_object_full(object->pointer);
- rcu_read_unlock();
+ if (cleanup) {
+ rcu_read_lock();
+ list_for_each_entry_rcu(object, &object_list, object_list)
+ delete_object_full(object->pointer);
+ rcu_read_unlock();
+ }
mutex_unlock(&scan_mutex);
}
return;
/* stop any memory operation tracing */
- atomic_set(&kmemleak_early_log, 0);
atomic_set(&kmemleak_enabled, 0);
/* check whether it is too early for a kernel thread */
}
early_param("kmemleak", kmemleak_boot_config);
+static void __init print_log_trace(struct early_log *log)
+{
+ struct stack_trace trace;
+
+ trace.nr_entries = log->trace_len;
+ trace.entries = log->trace;
+
+ pr_notice("Early log backtrace:\n");
+ print_stack_trace(&trace, 2);
+}
+
/*
* Kmemleak initialization.
*/
#ifdef CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF
if (!kmemleak_skip_disable) {
+ atomic_set(&kmemleak_early_log, 0);
kmemleak_disable();
return;
}
scan_area_cache = KMEM_CACHE(kmemleak_scan_area, SLAB_NOLEAKTRACE);
INIT_PRIO_TREE_ROOT(&object_tree_root);
+ if (crt_early_log >= ARRAY_SIZE(early_log))
+ pr_warning("Early log buffer exceeded (%d), please increase "
+ "DEBUG_KMEMLEAK_EARLY_LOG_SIZE\n", crt_early_log);
+
/* the kernel is still in UP mode, so disabling the IRQs is enough */
local_irq_save(flags);
- if (!atomic_read(&kmemleak_error)) {
+ atomic_set(&kmemleak_early_log, 0);
+ if (atomic_read(&kmemleak_error)) {
+ local_irq_restore(flags);
+ return;
+ } else
atomic_set(&kmemleak_enabled, 1);
- atomic_set(&kmemleak_early_log, 0);
- }
local_irq_restore(flags);
/*
case KMEMLEAK_ALLOC:
early_alloc(log);
break;
+ case KMEMLEAK_ALLOC_PERCPU:
+ early_alloc_percpu(log);
+ break;
case KMEMLEAK_FREE:
kmemleak_free(log->ptr);
break;
case KMEMLEAK_FREE_PART:
kmemleak_free_part(log->ptr, log->size);
break;
+ case KMEMLEAK_FREE_PERCPU:
+ kmemleak_free_percpu(log->ptr);
+ break;
case KMEMLEAK_NOT_LEAK:
kmemleak_not_leak(log->ptr);
break;
kmemleak_no_scan(log->ptr);
break;
default:
- WARN_ON(1);
+ kmemleak_warn("Unknown early log operation: %d\n",
+ log->op_type);
+ }
+
+ if (atomic_read(&kmemleak_warning)) {
+ print_log_trace(log);
+ atomic_set(&kmemleak_warning, 0);
}
}
}
if (atomic_read(&kmemleak_error)) {
/*
- * Some error occured and kmemleak was disabled. There is a
+ * Some error occurred and kmemleak was disabled. There is a
* small chance that kmemleak_disable() was called immediately
* after setting kmemleak_initialized and we may end up with
* two clean-up threads but serialized by scan_mutex.
projects / linux-flexiantxendom0-3.2.10.git / blobdiff