Merge tag 'sound-fix-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai...
[linux-2.6-block.git] / mm / kmemleak.c
index 31f01c5011e59414e95b888b2b3d515940ab72ab..91d67eaee0500796c9e5569fedc7cc5775002dda 100644 (file)
@@ -192,15 +192,15 @@ static struct kmem_cache *object_cache;
 static struct kmem_cache *scan_area_cache;
 
 /* set if tracing memory operations is enabled */
-static atomic_t kmemleak_enabled = ATOMIC_INIT(0);
+static int kmemleak_enabled;
 /* set in the late_initcall if there were no errors */
-static atomic_t kmemleak_initialized = ATOMIC_INIT(0);
+static int kmemleak_initialized;
 /* enables or disables early logging of the memory operations */
-static atomic_t kmemleak_early_log = ATOMIC_INIT(1);
+static int kmemleak_early_log = 1;
 /* set if a kmemleak warning was issued */
-static atomic_t kmemleak_warning = ATOMIC_INIT(0);
+static int kmemleak_warning;
 /* set if a fatal kmemleak error has occurred */
-static atomic_t kmemleak_error = ATOMIC_INIT(0);
+static int kmemleak_error;
 
 /* minimum and maximum address that may be valid pointers */
 static unsigned long min_addr = ULONG_MAX;
@@ -218,7 +218,8 @@ static int kmemleak_stack_scan = 1;
 static DEFINE_MUTEX(scan_mutex);
 /* setting kmemleak=on, will set this var, skipping the disable */
 static int kmemleak_skip_disable;
-
+/* If there are leaks that can be reported */
+static bool kmemleak_found_leaks;
 
 /*
  * Early object allocation/freeing logging. Kmemleak is initialized after the
@@ -267,7 +268,7 @@ static void kmemleak_disable(void);
 #define kmemleak_warn(x...)    do {            \
        pr_warning(x);                          \
        dump_stack();                           \
-       atomic_set(&kmemleak_warning, 1);       \
+       kmemleak_warning = 1;                   \
 } while (0)
 
 /*
@@ -805,7 +806,7 @@ static void __init log_early(int op_type, const void *ptr, size_t size,
        unsigned long flags;
        struct early_log *log;
 
-       if (atomic_read(&kmemleak_error)) {
+       if (kmemleak_error) {
                /* kmemleak stopped recording, just count the requests */
                crt_early_log++;
                return;
@@ -840,7 +841,7 @@ static void early_alloc(struct early_log *log)
        unsigned long flags;
        int i;
 
-       if (!atomic_read(&kmemleak_enabled) || !log->ptr || IS_ERR(log->ptr))
+       if (!kmemleak_enabled || !log->ptr || IS_ERR(log->ptr))
                return;
 
        /*
@@ -893,9 +894,9 @@ void __ref kmemleak_alloc(const void *ptr, size_t size, int min_count,
 {
        pr_debug("%s(0x%p, %zu, %d)\n", __func__, ptr, size, min_count);
 
-       if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
+       if (kmemleak_enabled && ptr && !IS_ERR(ptr))
                create_object((unsigned long)ptr, size, min_count, gfp);
-       else if (atomic_read(&kmemleak_early_log))
+       else if (kmemleak_early_log)
                log_early(KMEMLEAK_ALLOC, ptr, size, min_count);
 }
 EXPORT_SYMBOL_GPL(kmemleak_alloc);
@@ -919,11 +920,11 @@ void __ref kmemleak_alloc_percpu(const void __percpu *ptr, size_t 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))
+       if (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))
+       else if (kmemleak_early_log)
                log_early(KMEMLEAK_ALLOC_PERCPU, ptr, size, 0);
 }
 EXPORT_SYMBOL_GPL(kmemleak_alloc_percpu);
@@ -939,9 +940,9 @@ void __ref kmemleak_free(const void *ptr)
 {
        pr_debug("%s(0x%p)\n", __func__, ptr);
 
-       if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
+       if (kmemleak_enabled && ptr && !IS_ERR(ptr))
                delete_object_full((unsigned long)ptr);
-       else if (atomic_read(&kmemleak_early_log))
+       else if (kmemleak_early_log)
                log_early(KMEMLEAK_FREE, ptr, 0, 0);
 }
 EXPORT_SYMBOL_GPL(kmemleak_free);
@@ -959,9 +960,9 @@ void __ref kmemleak_free_part(const void *ptr, size_t size)
 {
        pr_debug("%s(0x%p)\n", __func__, ptr);
 
-       if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
+       if (kmemleak_enabled && ptr && !IS_ERR(ptr))
                delete_object_part((unsigned long)ptr, size);
-       else if (atomic_read(&kmemleak_early_log))
+       else if (kmemleak_early_log)
                log_early(KMEMLEAK_FREE_PART, ptr, size, 0);
 }
 EXPORT_SYMBOL_GPL(kmemleak_free_part);
@@ -979,11 +980,11 @@ void __ref kmemleak_free_percpu(const void __percpu *ptr)
 
        pr_debug("%s(0x%p)\n", __func__, ptr);
 
-       if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
+       if (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))
+       else if (kmemleak_early_log)
                log_early(KMEMLEAK_FREE_PERCPU, ptr, 0, 0);
 }
 EXPORT_SYMBOL_GPL(kmemleak_free_percpu);
@@ -999,9 +1000,9 @@ void __ref kmemleak_not_leak(const void *ptr)
 {
        pr_debug("%s(0x%p)\n", __func__, ptr);
 
-       if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
+       if (kmemleak_enabled && ptr && !IS_ERR(ptr))
                make_gray_object((unsigned long)ptr);
-       else if (atomic_read(&kmemleak_early_log))
+       else if (kmemleak_early_log)
                log_early(KMEMLEAK_NOT_LEAK, ptr, 0, 0);
 }
 EXPORT_SYMBOL(kmemleak_not_leak);
@@ -1019,9 +1020,9 @@ void __ref kmemleak_ignore(const void *ptr)
 {
        pr_debug("%s(0x%p)\n", __func__, ptr);
 
-       if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
+       if (kmemleak_enabled && ptr && !IS_ERR(ptr))
                make_black_object((unsigned long)ptr);
-       else if (atomic_read(&kmemleak_early_log))
+       else if (kmemleak_early_log)
                log_early(KMEMLEAK_IGNORE, ptr, 0, 0);
 }
 EXPORT_SYMBOL(kmemleak_ignore);
@@ -1041,9 +1042,9 @@ 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 && size && !IS_ERR(ptr))
+       if (kmemleak_enabled && ptr && size && !IS_ERR(ptr))
                add_scan_area((unsigned long)ptr, size, gfp);
-       else if (atomic_read(&kmemleak_early_log))
+       else if (kmemleak_early_log)
                log_early(KMEMLEAK_SCAN_AREA, ptr, size, 0);
 }
 EXPORT_SYMBOL(kmemleak_scan_area);
@@ -1061,9 +1062,9 @@ void __ref kmemleak_no_scan(const void *ptr)
 {
        pr_debug("%s(0x%p)\n", __func__, ptr);
 
-       if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
+       if (kmemleak_enabled && ptr && !IS_ERR(ptr))
                object_no_scan((unsigned long)ptr);
-       else if (atomic_read(&kmemleak_early_log))
+       else if (kmemleak_early_log)
                log_early(KMEMLEAK_NO_SCAN, ptr, 0, 0);
 }
 EXPORT_SYMBOL(kmemleak_no_scan);
@@ -1088,7 +1089,7 @@ static bool update_checksum(struct kmemleak_object *object)
  */
 static int scan_should_stop(void)
 {
-       if (!atomic_read(&kmemleak_enabled))
+       if (!kmemleak_enabled)
                return 1;
 
        /*
@@ -1382,9 +1383,12 @@ static void kmemleak_scan(void)
        }
        rcu_read_unlock();
 
-       if (new_leaks)
+       if (new_leaks) {
+               kmemleak_found_leaks = true;
+
                pr_info("%d new suspected memory leaks (see "
                        "/sys/kernel/debug/kmemleak)\n", new_leaks);
+       }
 
 }
 
@@ -1545,11 +1549,6 @@ static int kmemleak_open(struct inode *inode, struct file *file)
        return seq_open(file, &kmemleak_seq_ops);
 }
 
-static int kmemleak_release(struct inode *inode, struct file *file)
-{
-       return seq_release(inode, file);
-}
-
 static int dump_str_object_info(const char *str)
 {
        unsigned long flags;
@@ -1592,8 +1591,12 @@ static void kmemleak_clear(void)
                spin_unlock_irqrestore(&object->lock, flags);
        }
        rcu_read_unlock();
+
+       kmemleak_found_leaks = false;
 }
 
+static void __kmemleak_do_cleanup(void);
+
 /*
  * File write operation to configure kmemleak at run-time. The following
  * commands can be written to the /sys/kernel/debug/kmemleak file:
@@ -1606,7 +1609,8 @@ static void kmemleak_clear(void)
  *               disable it)
  *   scan      - trigger a memory scan
  *   clear     - mark all current reported unreferenced kmemleak objects as
- *               grey to ignore printing them
+ *               grey to ignore printing them, or free all kmemleak objects
+ *               if kmemleak has been disabled.
  *   dump=...  - dump information about the object found at the given address
  */
 static ssize_t kmemleak_write(struct file *file, const char __user *user_buf,
@@ -1616,9 +1620,6 @@ static ssize_t kmemleak_write(struct file *file, const char __user *user_buf,
        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;
@@ -1628,6 +1629,19 @@ static ssize_t kmemleak_write(struct file *file, const char __user *user_buf,
        if (ret < 0)
                return ret;
 
+       if (strncmp(buf, "clear", 5) == 0) {
+               if (kmemleak_enabled)
+                       kmemleak_clear();
+               else
+                       __kmemleak_do_cleanup();
+               goto out;
+       }
+
+       if (!kmemleak_enabled) {
+               ret = -EBUSY;
+               goto out;
+       }
+
        if (strncmp(buf, "off", 3) == 0)
                kmemleak_disable();
        else if (strncmp(buf, "stack=on", 8) == 0)
@@ -1651,8 +1665,6 @@ static ssize_t kmemleak_write(struct file *file, const char __user *user_buf,
                }
        } else if (strncmp(buf, "scan", 4) == 0)
                kmemleak_scan();
-       else if (strncmp(buf, "clear", 5) == 0)
-               kmemleak_clear();
        else if (strncmp(buf, "dump=", 5) == 0)
                ret = dump_str_object_info(buf + 5);
        else
@@ -1674,9 +1686,19 @@ static const struct file_operations kmemleak_fops = {
        .read           = seq_read,
        .write          = kmemleak_write,
        .llseek         = seq_lseek,
-       .release        = kmemleak_release,
+       .release        = seq_release,
 };
 
+static void __kmemleak_do_cleanup(void)
+{
+       struct kmemleak_object *object;
+
+       rcu_read_lock();
+       list_for_each_entry_rcu(object, &object_list, object_list)
+               delete_object_full(object->pointer);
+       rcu_read_unlock();
+}
+
 /*
  * Stop the memory scanning thread and free the kmemleak internal objects if
  * no previous scan thread (otherwise, kmemleak may still have some useful
@@ -1684,18 +1706,14 @@ static const struct file_operations kmemleak_fops = {
  */
 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();
 
-       if (cleanup) {
-               rcu_read_lock();
-               list_for_each_entry_rcu(object, &object_list, object_list)
-                       delete_object_full(object->pointer);
-               rcu_read_unlock();
-       }
+       if (!kmemleak_found_leaks)
+               __kmemleak_do_cleanup();
+       else
+               pr_info("Kmemleak disabled without freeing internal data. "
+                       "Reclaim the memory with \"echo clear > /sys/kernel/debug/kmemleak\"\n");
        mutex_unlock(&scan_mutex);
 }
 
@@ -1708,14 +1726,14 @@ static DECLARE_WORK(cleanup_work, kmemleak_do_cleanup);
 static void kmemleak_disable(void)
 {
        /* atomically check whether it was already invoked */
-       if (atomic_cmpxchg(&kmemleak_error, 0, 1))
+       if (cmpxchg(&kmemleak_error, 0, 1))
                return;
 
        /* stop any memory operation tracing */
-       atomic_set(&kmemleak_enabled, 0);
+       kmemleak_enabled = 0;
 
        /* check whether it is too early for a kernel thread */
-       if (atomic_read(&kmemleak_initialized))
+       if (kmemleak_initialized)
                schedule_work(&cleanup_work);
 
        pr_info("Kernel memory leak detector disabled\n");
@@ -1757,9 +1775,10 @@ void __init kmemleak_init(void)
        int i;
        unsigned long flags;
 
+       kmemleak_early_log = 0;
+
 #ifdef CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF
        if (!kmemleak_skip_disable) {
-               atomic_set(&kmemleak_early_log, 0);
                kmemleak_disable();
                return;
        }
@@ -1777,12 +1796,11 @@ void __init kmemleak_init(void)
 
        /* the kernel is still in UP mode, so disabling the IRQs is enough */
        local_irq_save(flags);
-       atomic_set(&kmemleak_early_log, 0);
-       if (atomic_read(&kmemleak_error)) {
+       if (kmemleak_error) {
                local_irq_restore(flags);
                return;
        } else
-               atomic_set(&kmemleak_enabled, 1);
+               kmemleak_enabled = 1;
        local_irq_restore(flags);
 
        /*
@@ -1826,9 +1844,9 @@ void __init kmemleak_init(void)
                                      log->op_type);
                }
 
-               if (atomic_read(&kmemleak_warning)) {
+               if (kmemleak_warning) {
                        print_log_trace(log);
-                       atomic_set(&kmemleak_warning, 0);
+                       kmemleak_warning = 0;
                }
        }
 }
@@ -1840,9 +1858,9 @@ static int __init kmemleak_late_init(void)
 {
        struct dentry *dentry;
 
-       atomic_set(&kmemleak_initialized, 1);
+       kmemleak_initialized = 1;
 
-       if (atomic_read(&kmemleak_error)) {
+       if (kmemleak_error) {
                /*
                 * Some error occurred and kmemleak was disabled. There is a
                 * small chance that kmemleak_disable() was called immediately