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authorCatalin Marinas <catalin.marinas@arm.com>2011-09-29 11:50:07 +0100
committerCatalin Marinas <catalin.marinas@arm.com>2011-12-02 16:12:42 +0000
commit74341703edca6bc68a165a18453071b097828407 (patch)
tree8cb5c8423849acfb4c89a192548e95dfce49efd7
parentb66930052abf2e41b8a978ae265303917cbe6fa0 (diff)
kmemleak: Report previously found leaks even after an error
If an error fatal to kmemleak (like memory allocation failure) happens, kmemleak disables itself but it also removes the access to any previously found memory leaks. This patch allows read-only access to the kmemleak debugfs interface but disables any other action. Reported-by: Nick Bowler <nbowler@elliptictech.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
-rw-r--r--mm/kmemleak.c22
1 files changed, 13 insertions, 9 deletions
diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index e8c905b70aa8..b4f4e6021c1b 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -1473,9 +1473,6 @@ static const struct seq_operations kmemleak_seq_ops = {
static int kmemleak_open(struct inode *inode, struct file *file)
{
- if (!atomic_read(&kmemleak_enabled))
- return -EBUSY;
-
return seq_open(file, &kmemleak_seq_ops);
}
@@ -1549,6 +1546,9 @@ 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;
@@ -1608,20 +1608,24 @@ static const struct file_operations kmemleak_fops = {
};
/*
- * 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);
}