[PATCH] PCI: take the rescan lock when adding devices during host probe

From: Bartosz Golaszewski
Date: Thu Sep 26 2024 - 09:09:44 EST


From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>

Since adding the PCI power control code, we may end up with a race
between the pwrctl platform device rescanning the bus and the host
controller probe function. The latter needs to take the rescan lock when
adding devices or may crash.

Reported-by: Konrad Dybcio <konradybcio@xxxxxxxxxx>
Fixes: 4565d2652a37 ("PCI/pwrctl: Add PCI power control core code")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
---
drivers/pci/probe.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 4f68414c3086..f1615805f5b0 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -3105,7 +3105,9 @@ int pci_host_probe(struct pci_host_bridge *bridge)
list_for_each_entry(child, &bus->children, node)
pcie_bus_configure_settings(child);

+ pci_lock_rescan_remove();
pci_bus_add_devices(bus);
+ pci_unlock_rescan_remove();
return 0;
}
EXPORT_SYMBOL_GPL(pci_host_probe);
--
2.30.2