diff options
| -rw-r--r-- | mm/kmemleak.c | 63 |
1 files changed, 30 insertions, 33 deletions
diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 3c2b24c49a84..7cfb7d014a20 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -1101,6 +1101,11 @@ static void *kmemleak_seq_start(struct seq_file *seq, loff_t *pos) { struct kmemleak_object *object; loff_t n = *pos; + int err; + + err = mutex_lock_interruptible(&scan_mutex); + if (err < 0) + return ERR_PTR(err); rcu_read_lock(); list_for_each_entry_rcu(object, &object_list, object_list) { @@ -1144,8 +1149,15 @@ static void *kmemleak_seq_next(struct seq_file *seq, void *v, loff_t *pos) */ static void kmemleak_seq_stop(struct seq_file *seq, void *v) { - if (v) - put_object(v); + if (!IS_ERR(v)) { + /* + * kmemleak_seq_start may return ERR_PTR if the scan_mutex + * waiting was interrupted, so only release it if !IS_ERR. + */ + mutex_unlock(&scan_mutex); + if (v) + put_object(v); + } } /* @@ -1172,36 +1184,15 @@ static const struct seq_operations kmemleak_seq_ops = { static int kmemleak_open(struct inode *inode, struct file *file) { - int ret = 0; - if (!atomic_read(&kmemleak_enabled)) return -EBUSY; - ret = mutex_lock_interruptible(&scan_mutex); - if (ret < 0) - goto out; - if (file->f_mode & FMODE_READ) { - ret = seq_open(file, &kmemleak_seq_ops); - if (ret < 0) - goto scan_unlock; - } - return ret; - -scan_unlock: - mutex_unlock(&scan_mutex); -out: - return ret; + return seq_open(file, &kmemleak_seq_ops); } static int kmemleak_release(struct inode *inode, struct file *file) { - int ret = 0; - - if (file->f_mode & FMODE_READ) - seq_release(inode, file); - mutex_unlock(&scan_mutex); - - return ret; + return seq_release(inode, file); } /* @@ -1221,15 +1212,17 @@ static ssize_t kmemleak_write(struct file *file, const char __user *user_buf, { char buf[64]; int buf_size; - - if (!atomic_read(&kmemleak_enabled)) - return -EBUSY; + int ret; buf_size = min(size, (sizeof(buf) - 1)); if (strncpy_from_user(buf, user_buf, buf_size) < 0) return -EFAULT; buf[buf_size] = 0; + ret = mutex_lock_interruptible(&scan_mutex); + if (ret < 0) + return ret; + if (strncmp(buf, "off", 3) == 0) kmemleak_disable(); else if (strncmp(buf, "stack=on", 8) == 0) @@ -1242,11 +1235,10 @@ static ssize_t kmemleak_write(struct file *file, const char __user *user_buf, stop_scan_thread(); else if (strncmp(buf, "scan=", 5) == 0) { unsigned long secs; - int err; - err = strict_strtoul(buf + 5, 0, &secs); - if (err < 0) - return err; + ret = strict_strtoul(buf + 5, 0, &secs); + if (ret < 0) + goto out; stop_scan_thread(); if (secs) { jiffies_scan_wait = msecs_to_jiffies(secs * 1000); @@ -1255,7 +1247,12 @@ static ssize_t kmemleak_write(struct file *file, const char __user *user_buf, } else if (strncmp(buf, "scan", 4) == 0) kmemleak_scan(); else - return -EINVAL; + ret = -EINVAL; + +out: + mutex_unlock(&scan_mutex); + if (ret < 0) + return ret; /* ignore the rest of the buffer, only one command at a time */ *ppos += size; |