kmemleak: Dump object information on request
By writing dump=<addr> to the kmemleak file, kmemleak will look up an
object with that address and dump the information it has about it to
syslog. This is useful in debugging memory leaks.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/Documentation/kmemleak.txt b/Documentation/kmemleak.txt
index 8906803..c223785 100644
--- a/Documentation/kmemleak.txt
+++ b/Documentation/kmemleak.txt
@@ -42,6 +42,7 @@
scan=<secs> - set the automatic memory scanning period in seconds
(default 600, 0 to stop the automatic scanning)
scan - trigger a memory scan
+ dump=<addr> - dump information about the object found at <addr>
Kmemleak can also be disabled at boot-time by passing "kmemleak=off" on
the kernel command line.
diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 6debe0d..c977f7a 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -331,6 +331,7 @@
object->comm, object->pid, object->jiffies);
pr_notice(" min_count = %d\n", object->min_count);
pr_notice(" count = %d\n", object->count);
+ pr_notice(" flags = 0x%lx\n", object->flags);
pr_notice(" backtrace:\n");
print_stack_trace(&trace, 4);
}
@@ -1307,6 +1308,27 @@
return seq_release(inode, file);
}
+static int dump_str_object_info(const char *str)
+{
+ unsigned long flags;
+ struct kmemleak_object *object;
+ unsigned long addr;
+
+ addr= simple_strtoul(str, NULL, 0);
+ object = find_and_get_object(addr, 0);
+ if (!object) {
+ pr_info("Unknown object at 0x%08lx\n", addr);
+ return -EINVAL;
+ }
+
+ spin_lock_irqsave(&object->lock, flags);
+ dump_object_info(object);
+ spin_unlock_irqrestore(&object->lock, flags);
+
+ put_object(object);
+ return 0;
+}
+
/*
* File write operation to configure kmemleak at run-time. The following
* commands can be written to the /sys/kernel/debug/kmemleak file:
@@ -1318,6 +1340,7 @@
* scan=... - set the automatic memory scanning period in seconds (0 to
* disable it)
* scan - trigger a memory scan
+ * dump=... - dump information about the object found at the given address
*/
static ssize_t kmemleak_write(struct file *file, const char __user *user_buf,
size_t size, loff_t *ppos)
@@ -1358,6 +1381,8 @@
}
} else if (strncmp(buf, "scan", 4) == 0)
kmemleak_scan();
+ else if (strncmp(buf, "dump=", 5) == 0)
+ ret = dump_str_object_info(buf + 5);
else
ret = -EINVAL;