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PCI: hv: Fix synchronization between channel callback and hv_pci_bus_exit()

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[ 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) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Link: https://lore.kernel.org/r/20220511223207.3386-3-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
This commit is contained in:
Andrea Parri (Microsoft) 2022-05-12 00:32:07 +02:00 committed by Wei Liu
parent 9937fa6d1e
commit b4927bd272
1 changed files with 19 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
drivers/pci/controller/pci-hyperv.c
View File

@ -3664,6 +3664,7 @@ free_bus:
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;
}