usb: ehci-fsl: Fix use of private data to avoid -Wflex-array-member-not-at-end warning

In the course of fixing up the usages of flexible arrays, Gustavo
submitted a patch updating the ehci-fsl driver.  However, the patch
was wrong because the driver was using the .priv member of the
ehci_hcd structure incorrectly.  The private data is not supposed to
be a wrapper containing the ehci_hcd structure; it is supposed to be a
sub-structure stored in the .priv member.

Fix the problem by replacing the ehci_fsl structure with
ehci_fsl_priv, containing only the private data, along with a suitable
conversion macro for accessing it.  This removes the problem of having
data follow a flexible array member.

Reported-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/linux-usb/Z-R9BcnSzrRv5FX_@kspp/
Reviewed-by: Kees Cook <kees@kernel.org>
Link: https://lore.kernel.org/r/8139e4cc-4e5c-40e2-9c4b-717ad3215868@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
index 26f13278d4d6982ae2ca50948f930189f1e911a9..6ed2fa5418a4e47cb780aa721c586260c3142643 100644 (file)
--- a/drivers/usb/host/ehci-fsl.c
+++ b/drivers/usb/host/ehci-fsl.c
@@ -410,15 +410,13 @@ static int ehci_fsl_setup(struct usb_hcd *hcd)
        return retval;
 }
 
-struct ehci_fsl {
-       struct ehci_hcd ehci;
-
-#ifdef CONFIG_PM
+struct ehci_fsl_priv {
        /* Saved USB PHY settings, need to restore after deep sleep. */
        u32 usb_ctrl;
-#endif
 };
 
+#define hcd_to_ehci_fsl_priv(h) ((struct ehci_fsl_priv *) hcd_to_ehci(h)->priv)
+
 #ifdef CONFIG_PM
 
 #ifdef CONFIG_PPC_MPC512x
@@ -566,17 +564,10 @@ static inline int ehci_fsl_mpc512x_drv_resume(struct device *dev)
 }
 #endif /* CONFIG_PPC_MPC512x */
 
-static struct ehci_fsl *hcd_to_ehci_fsl(struct usb_hcd *hcd)
-{
-       struct ehci_hcd *ehci = hcd_to_ehci(hcd);
-
-       return container_of(ehci, struct ehci_fsl, ehci);
-}
-
 static int ehci_fsl_drv_suspend(struct device *dev)
 {
        struct usb_hcd *hcd = dev_get_drvdata(dev);
-       struct ehci_fsl *ehci_fsl = hcd_to_ehci_fsl(hcd);
+       struct ehci_fsl_priv *priv = hcd_to_ehci_fsl_priv(hcd);
        void __iomem *non_ehci = hcd->regs;
 
        if (of_device_is_compatible(dev->parent->of_node,
@@ -589,14 +580,14 @@ static int ehci_fsl_drv_suspend(struct device *dev)
        if (!fsl_deep_sleep())
                return 0;
 
-       ehci_fsl->usb_ctrl = ioread32be(non_ehci + FSL_SOC_USB_CTRL);
+       priv->usb_ctrl = ioread32be(non_ehci + FSL_SOC_USB_CTRL);
        return 0;
 }
 
 static int ehci_fsl_drv_resume(struct device *dev)
 {
        struct usb_hcd *hcd = dev_get_drvdata(dev);
-       struct ehci_fsl *ehci_fsl = hcd_to_ehci_fsl(hcd);
+       struct ehci_fsl_priv *priv = hcd_to_ehci_fsl_priv(hcd);
        struct ehci_hcd *ehci = hcd_to_ehci(hcd);
        void __iomem *non_ehci = hcd->regs;
 
@@ -612,7 +603,7 @@ static int ehci_fsl_drv_resume(struct device *dev)
        usb_root_hub_lost_power(hcd->self.root_hub);
 
        /* Restore USB PHY settings and enable the controller. */
-       iowrite32be(ehci_fsl->usb_ctrl, non_ehci + FSL_SOC_USB_CTRL);
+       iowrite32be(priv->usb_ctrl, non_ehci + FSL_SOC_USB_CTRL);
 
        ehci_reset(ehci);
        ehci_fsl_reinit(ehci);
@@ -671,7 +662,7 @@ static int ehci_start_port_reset(struct usb_hcd *hcd, unsigned port)
 #endif /* CONFIG_USB_OTG */
 
 static const struct ehci_driver_overrides ehci_fsl_overrides __initconst = {
-       .extra_priv_size = sizeof(struct ehci_fsl),
+       .extra_priv_size = sizeof(struct ehci_fsl_priv),
        .reset = ehci_fsl_setup,
 };