On Fri, Jan 11, 2013 at 4:32 PM, Daniel Baluta <daniel.baluta@xxxxxxxxx> wrote: > > > On Fri, Jan 11, 2013 at 4:02 PM, Catalin Marinas <catalin.marinas@xxxxxxx> > wrote: >> >> On Fri, Jan 11, 2013 at 01:51:43PM +0000, Alexandru Copot wrote: >> > 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); >> >> Please add a comment above this call in case people later wonder why >> this annotation is needed. >> > > Thanks Cătălin. > > So, kememleak cannot handle this kind of pointer aliases? > Also, I wonder if phys_to_virt(virt_to_phys(x)) == x holds true all the > time. Sending this again as it seems that linux-kernel rejected it because of HTML format. Sorry for the noise. thanks, Daniel. _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
