diff options
| author | Long Li <longli@microsoft.com> | 2021-08-30 16:13:27 -0700 |
|---|---|---|
| committer | Wei Liu <wei.liu@kernel.org> | 2021-09-24 09:34:29 +0000 |
| commit | 41608b64b10b80fe00dd253cd8326ec8ad85930f (patch) | |
| tree | 7610b212a54973f9cb252b10e85a4aac75196653 /drivers/pci | |
| parent | dfb5c1e12c28e35e4d4e5bc8022b0e9d585b89a7 (diff) | |
| download | lwn-41608b64b10b80fe00dd253cd8326ec8ad85930f.tar.gz lwn-41608b64b10b80fe00dd253cd8326ec8ad85930f.zip | |
PCI: hv: Fix sleep while in non-sleep context when removing child devices from the bus
In hv_pci_bus_exit, the code is holding a spinlock while calling
pci_destroy_slot(), which takes a mutex.
This is not safe for spinlock. Fix this by moving the children to be
deleted to a list on the stack, and removing them after spinlock is
released.
Fixes: 94d22763207a ("PCI: hv: Fix a race condition when removing the device")
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Rob Herring <robh@kernel.org>
Cc: "Krzysztof Wilczyński" <kw@linux.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Michael Kelley <mikelley@microsoft.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/linux-hyperv/20210823152130.GA21501@kili/
Signed-off-by: Long Li <longli@microsoft.com>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/1630365207-20616-1-git-send-email-longli@linuxonhyperv.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/controller/pci-hyperv.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c index a53bd8728d0d..fc1a29acadbb 100644 --- a/drivers/pci/controller/pci-hyperv.c +++ b/drivers/pci/controller/pci-hyperv.c @@ -3229,9 +3229,17 @@ static int hv_pci_bus_exit(struct hv_device *hdev, bool keep_devs) return 0; if (!keep_devs) { - /* Delete any children which might still exist. */ + struct list_head removed; + + /* Move all present children to the list on stack */ + INIT_LIST_HEAD(&removed); spin_lock_irqsave(&hbus->device_list_lock, flags); - list_for_each_entry_safe(hpdev, tmp, &hbus->children, list_entry) { + list_for_each_entry_safe(hpdev, tmp, &hbus->children, list_entry) + list_move_tail(&hpdev->list_entry, &removed); + spin_unlock_irqrestore(&hbus->device_list_lock, flags); + + /* Remove all children in the list */ + list_for_each_entry_safe(hpdev, tmp, &removed, list_entry) { list_del(&hpdev->list_entry); if (hpdev->pci_slot) pci_destroy_slot(hpdev->pci_slot); @@ -3239,7 +3247,6 @@ static int hv_pci_bus_exit(struct hv_device *hdev, bool keep_devs) put_pcichild(hpdev); put_pcichild(hpdev); } - spin_unlock_irqrestore(&hbus->device_list_lock, flags); } ret = hv_send_resources_released(hdev); |