From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: "linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>
Subject: [RFC/PATCH] PCI: Protect pci_reassign_bridge_resources() against concurrent addition/removal
Date: Mon, 24 Jun 2019 14:32:19 +1000 [thread overview]
Message-ID: <02ca29627597445442bb14c069678e549429dace.camel@kernel.crashing.org> (raw)
pci_reassign_bridge_resources() can be called by pci_resize_resource()
at runtime.
It will walk the PCI tree up and down, and isn't currently protected
against any changes or hotplug operation.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -2104,6 +2104,8 @@ int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type)
unsigned int i;
int ret;
+ down_read(&pci_bus_sem);
+
/* Walk to the root hub, releasing bridge BARs when possible */
next = bridge;
do {
@@ -2160,6 +2162,7 @@ int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type)
}
free_list(&saved);
+ up_read(&pci_bus_sem);
return 0;
cleanup:
@@ -2188,6 +2191,7 @@ int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type)
pci_setup_bridge(bridge->subordinate);
}
free_list(&saved);
+ up_read(&pci_bus_sem);
return ret;
}
next reply other threads:[~2019-06-24 4:32 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-24 4:32 Benjamin Herrenschmidt [this message]
2019-08-21 13:08 ` [RFC/PATCH] PCI: Protect pci_reassign_bridge_resources() against concurrent addition/removal Bjorn Helgaas
2019-09-23 21:50 ` Bjorn Helgaas
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