When we rmmod aer_inject module, there is a race condition window between pci_bus_ops_pop()
and pci_bus_set_ops() in aer_inject_exit, eg. pci_read_aer/pci_write_aer was called between
them. So introduce pci_bus_ops_get() to avoid this.
Signed-off-by: Yijing Wang <wangyijing@xxxxxxxxxx>
---
drivers/pci/pcie/aer/aer_inject.c | 21 ++++++++++++++++++---
1 files changed, 18 insertions(+), 3 deletions(-)
diff --git a/drivers/pci/pcie/aer/aer_inject.c b/drivers/pci/pcie/aer/aer_inject.c
index 0f00a27..442147b 100644
--- a/drivers/pci/pcie/aer/aer_inject.c
+++ b/drivers/pci/pcie/aer/aer_inject.c
@@ -67,6 +67,8 @@ struct pci_bus_ops {
struct pci_ops *ops;
};
+#define to_pci_bus_ops(n) container_of(n, struct pci_bus_ops, list)
+
static LIST_HEAD(einjected);
static LIST_HEAD(pci_bus_ops_list);
@@ -160,6 +162,18 @@ static struct pci_bus_ops *pci_bus_ops_pop(void)
return bus_ops;
}
+static struct pci_bus_ops *pci_bus_ops_get(struct pci_bus_ops *from)
+{
+ struct pci_bus_ops *bus_ops = NULL;
+ struct list_head *n;
+
+ n = from ? from->list.next : pci_bus_ops_list.next;
+ if (n != &pci_bus_ops_list)
+ bus_ops = to_pci_bus_ops(n);
+
+ return bus_ops;
+}
+
static u32 *find_pci_config_dword(struct aer_error *err, int where,
int *prw1cs)
{
@@ -540,14 +554,15 @@ static void __exit aer_inject_exit(void)
{
struct aer_error *err, *err_next;
unsigned long flags;
- struct pci_bus_ops *bus_ops;
+ struct pci_bus_ops *bus_ops = NULL;
misc_deregister(&aer_inject_device);
- while ((bus_ops = pci_bus_ops_pop())) {
+ while ((bus_ops = pci_bus_ops_get(bus_ops)))
pci_bus_set_ops(bus_ops->bus, bus_ops->ops);
+
+ while ((bus_ops = pci_bus_ops_pop()))
kfree(bus_ops);
- }
spin_lock_irqsave(&inject_lock, flags);
list_for_each_entry_safe(err, err_next, &einjected, list) {
--
1.7.1
--
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