[RFC PATCH 17/30] PCI: endpoint: Protect concurrent access to pci_epf_ops with mutex
From: Kishon Vijay Abraham I <hidden>
Date: 2019-06-04 13:18:37
Also in:
linux-arm-kernel, linux-omap, linux-pci, linux-rockchip, lkml
Subsystem:
pci endpoint subsystem, pci subsystem, the rest · Maintainers:
Manivannan Sadhasivam, Krzysztof Wilczyński, Bjorn Helgaas, Linus Torvalds
Protect concurrent access to pci_epf_ops with mutex. Signed-off-by: Kishon Vijay Abraham I <redacted> --- drivers/pci/endpoint/pci-epf-core.c | 11 ++++++++++- include/linux/pci-epf.h | 3 +++ 2 files changed, 13 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c
index 93f28c65ace0..6e0648991b5c 100644
--- a/drivers/pci/endpoint/pci-epf-core.c
+++ b/drivers/pci/endpoint/pci-epf-core.c@@ -35,7 +35,9 @@ void pci_epf_unbind(struct pci_epf *epf) return; } + mutex_lock(&epf->lock); epf->driver->ops->unbind(epf); + mutex_unlock(&epf->lock); module_put(epf->driver->owner); } EXPORT_SYMBOL_GPL(pci_epf_unbind);
@@ -49,6 +51,8 @@ EXPORT_SYMBOL_GPL(pci_epf_unbind); */ int pci_epf_bind(struct pci_epf *epf) { + int ret; + if (!epf->driver) { dev_WARN(&epf->dev, "epf device not bound to driver\n"); return -EINVAL;
@@ -57,7 +61,11 @@ int pci_epf_bind(struct pci_epf *epf) if (!try_module_get(epf->driver->owner)) return -EAGAIN; - return epf->driver->ops->bind(epf); + mutex_lock(&epf->lock); + ret = epf->driver->ops->bind(epf); + mutex_unlock(&epf->lock); + + return ret; } EXPORT_SYMBOL_GPL(pci_epf_bind);
@@ -252,6 +260,7 @@ struct pci_epf *pci_epf_create(const char *name) device_initialize(dev); dev->bus = &pci_epf_bus_type; dev->type = &pci_epf_type; + mutex_init(&epf->lock); ret = dev_set_name(dev, "%s", name); if (ret) {
diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
index 4993f7f6439b..bcdf4f07bde7 100644
--- a/include/linux/pci-epf.h
+++ b/include/linux/pci-epf.h@@ -110,6 +110,7 @@ struct pci_epf_bar { * @driver: the EPF driver to which this EPF device is bound * @list: to add pci_epf as a list of PCI endpoint functions to pci_epc * @nb: notifier block to notify EPF of any EPC events (like linkup) + * @lock: mutex to protect pci_epf_ops */ struct pci_epf { struct device dev;
@@ -124,6 +125,8 @@ struct pci_epf { struct pci_epf_driver *driver; struct list_head list; struct notifier_block nb; + /* mutex to protect against concurrent access of pci_epf_ops */ + struct mutex lock; }; #define to_pci_epf(epf_dev) container_of((epf_dev), struct pci_epf, dev)
--
2.17.1