[ Similarly to commit a765ed47e4516 ("PCI: hv: Fix synchronization
between channel callback and hv_compose_msi_msg()"): ]
The (on-stack) teardown packet becomes invalid once the completion
timeout in hv_pci_bus_exit() has expired and hv_pci_bus_exit() has
returned. Prevent the channel callback from accessing the invalid
packet by removing the ID associated to such packet from the VMbus
requestor in hv_pci_bus_exit().
Signed-off-by: Andrea Parri (Microsoft) <[email protected]>
Reviewed-by: Michael Kelley <[email protected]>
---
drivers/pci/controller/pci-hyperv.c | 26 +++++++++++++++++++-------
1 file changed, 19 insertions(+), 7 deletions(-)
diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index a06e2cf946580..db814f7b93baa 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -3664,6 +3664,7 @@ static int hv_pci_probe(struct hv_device *hdev,
static int hv_pci_bus_exit(struct hv_device *hdev, bool keep_devs)
{
struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
+ struct vmbus_channel *chan = hdev->channel;
struct {
struct pci_packet teardown_packet;
u8 buffer[sizeof(struct pci_message)];
@@ -3671,13 +3672,14 @@ static int hv_pci_bus_exit(struct hv_device *hdev, bool keep_devs)
struct hv_pci_compl comp_pkt;
struct hv_pci_dev *hpdev, *tmp;
unsigned long flags;
+ u64 trans_id;
int ret;
/*
* After the host sends the RESCIND_CHANNEL message, it doesn't
* access the per-channel ringbuffer any longer.
*/
- if (hdev->channel->rescind)
+ if (chan->rescind)
return 0;
if (!keep_devs) {
@@ -3714,16 +3716,26 @@ static int hv_pci_bus_exit(struct hv_device *hdev, bool keep_devs)
pkt.teardown_packet.compl_ctxt = &comp_pkt;
pkt.teardown_packet.message[0].type = PCI_BUS_D0EXIT;
- ret = vmbus_sendpacket(hdev->channel, &pkt.teardown_packet.message,
- sizeof(struct pci_message),
- (unsigned long)&pkt.teardown_packet,
- VM_PKT_DATA_INBAND,
- VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+ ret = vmbus_sendpacket_getid(chan, &pkt.teardown_packet.message,
+ sizeof(struct pci_message),
+ (unsigned long)&pkt.teardown_packet,
+ &trans_id, VM_PKT_DATA_INBAND,
+ VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
if (ret)
return ret;
- if (wait_for_completion_timeout(&comp_pkt.host_event, 10 * HZ) == 0)
+ if (wait_for_completion_timeout(&comp_pkt.host_event, 10 * HZ) == 0) {
+ /*
+ * The completion packet on the stack becomes invalid after
+ * 'return'; remove the ID from the VMbus requestor if the
+ * identifier is still mapped to/associated with the packet.
+ *
+ * Cf. hv_pci_onchannelcallback().
+ */
+ vmbus_request_addr_match(chan, trans_id,
+ (unsigned long)&pkt.teardown_packet);
return -ETIMEDOUT;
+ }
return 0;
}
--
2.25.1