While doing simple IPv6 tests in KVM virtual machines,
(add an IPv6 address to eth0) kmemleak complains about
an unreferenced object:
unreferenced object 0xffff88001e804120 (size 32):
comm "softirq", pid 0, jiffies 4294900928 (age 631.544s)
hex dump (first 32 bytes):
28 cb fd 1d 00 00 00 00 0c 00 00 00 01 00 01 00 (...............
02 d0 83 1d 00 00 00 00 6e 00 00 00 00 00 00 00 ........n.......
backtrace:
[<ffffffff815ed721>] kmemleak_alloc+0x21/0x50
[<ffffffff8111d0b0>] __kmalloc+0xe0/0x160
[<ffffffff81362b7c>] virtqueue_add_buf+0x1fc/0x3d0
[<ffffffff8140cbd3>] start_xmit+0x153/0x3a0
[<ffffffff8150887e>] dev_hard_start_xmit+0x21e/0x470
[<ffffffff815247ce>] sch_direct_xmit+0xfe/0x280
[<ffffffff81509014>] dev_queue_xmit+0x1f4/0x5d0
[<ffffffff81592e91>] ip6_finish_output2+0x101/0x450
[<ffffffff81595ae8>] ip6_finish_output+0x98/0x200
[<ffffffff81595ca1>] ip6_output+0x51/0x1b0
[<ffffffff815b51af>] mld_sendpack+0x19f/0x360
[<ffffffff815b59b4>] mld_ifc_timer_expire+0x194/0x290
[<ffffffff8104b794>] call_timer_fn+0x74/0xf0
[<ffffffff8104bb1b>] run_timer_softirq+0x18b/0x220
[<ffffffff81045f81>] __do_softirq+0xe1/0x1c0
[<ffffffff8160a4fc>] call_softirq+0x1c/0x30
Seems the function vring_add_indirect stores an array of
struct vring_desc by using virt_to_phys and kmemleak
doesn't track the pointer.
The following patch can fix this.
Signed-off-by: Alexandru Copot <alex.mihai.c@xxxxxxxxx>
CC: Daniel Baluta <dbaluta@xxxxxxxxxxx>
---
drivers/virtio/virtio_ring.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index ffd7e7d..e0b591b 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -23,6 +23,7 @@
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/hrtimer.h>
+#include <linux/kmemleak.h>
/* virtio guest is communicating with a virtual "device" that actually runs on
* a host processor. Memory barriers are used to control SMP effects. */
@@ -140,6 +141,7 @@ static int vring_add_indirect(struct vring_virtqueue *vq,
desc = kmalloc((out + in) * sizeof(struct vring_desc), gfp);
if (!desc)
return -ENOMEM;
+ kmemleak_not_leak(desc);
/* Transfer entries from the sg list into the indirect page */
for (i = 0; i < out; i++) {
--
1.8.1
_______________________________________________
Virtualization mailing list
Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
