Driver core: change add_uevent_var to use a struct

This changes the uevent buffer functions to use a struct instead of a
long list of parameters. It does no longer require the caller to do the
proper buffer termination and size accounting, which is currently wrong
in some places. It fixes a known bug where parts of the uevent
environment are overwritten because of wrong index calculations.

Many thanks to Mathieu Desnoyers for finding bugs and improving the
error handling.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 14 insertions, 43 deletions

diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index 63b1243a9139..6273a5197e6a 100644
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -576,12 +576,9 @@ static int usb_device_match(struct device *dev, struct device_driver *drv)
 }
 
 #ifdef  CONFIG_HOTPLUG
-static int usb_uevent(struct device *dev, char **envp, int num_envp,
-                      char *buffer, int buffer_size)
+static int usb_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
         struct usb_device *usb_dev;
-        int i = 0;
-        int length = 0;
 
         if (!dev)
                 return -ENODEV;
@@ -610,51 +607,39 @@ static int usb_uevent(struct device *dev, char **envp, int num_envp,
          * all the device descriptors we don't tell them about.  Or
          * act as usermode drivers.
          */
-        if (add_uevent_var(envp, num_envp, &i,
-                           buffer, buffer_size, &length,
-                           "DEVICE=/proc/bus/usb/%03d/%03d",
+        if (add_uevent_var(env, "DEVICE=/proc/bus/usb/%03d/%03d",
                            usb_dev->bus->busnum, usb_dev->devnum))
                 return -ENOMEM;
 #endif
 
         /* per-device configurations are common */
-        if (add_uevent_var(envp, num_envp, &i,
-                           buffer, buffer_size, &length,
-                           "PRODUCT=%x/%x/%x",
+        if (add_uevent_var(env, "PRODUCT=%x/%x/%x",
                            le16_to_cpu(usb_dev->descriptor.idVendor),
                            le16_to_cpu(usb_dev->descriptor.idProduct),
                            le16_to_cpu(usb_dev->descriptor.bcdDevice)))
                 return -ENOMEM;
 
         /* class-based driver binding models */
-        if (add_uevent_var(envp, num_envp, &i,
-                           buffer, buffer_size, &length,
-                           "TYPE=%d/%d/%d",
+        if (add_uevent_var(env, "TYPE=%d/%d/%d",
                            usb_dev->descriptor.bDeviceClass,
                            usb_dev->descriptor.bDeviceSubClass,
                            usb_dev->descriptor.bDeviceProtocol))
                 return -ENOMEM;
 
-        if (add_uevent_var(envp, num_envp, &i,
-                           buffer, buffer_size, &length,
-                           "BUSNUM=%03d",
+        if (add_uevent_var(env, "BUSNUM=%03d",
                            usb_dev->bus->busnum))
                 return -ENOMEM;
 
-        if (add_uevent_var(envp, num_envp, &i,
-                           buffer, buffer_size, &length,
-                           "DEVNUM=%03d",
+        if (add_uevent_var(env, "DEVNUM=%03d",
                            usb_dev->devnum))
                 return -ENOMEM;
 
-        envp[i] = NULL;
         return 0;
 }
 
 #else
 
-static int usb_uevent(struct device *dev, char **envp,
-                      int num_envp, char *buffer, int buffer_size)
+static int usb_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
         return -ENODEV;
 }
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index d8f7b089a8f0..95a49d8efe7a 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1339,14 +1339,11 @@ void usb_release_interface(struct device *dev)
 }
 
 #ifdef  CONFIG_HOTPLUG
-static int usb_if_uevent(struct device *dev, char **envp, int num_envp,
-                 char *buffer, int buffer_size)
+static int usb_if_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
         struct usb_device *usb_dev;
         struct usb_interface *intf;
         struct usb_host_interface *alt;
-        int i = 0;
-        int length = 0;
 
         if (!dev)
                 return -ENODEV;
@@ -1359,39 +1356,30 @@ static int usb_if_uevent(struct device *dev, char **envp, int num_envp,
         alt = intf->cur_altsetting;
 
 #ifdef CONFIG_USB_DEVICEFS
-        if (add_uevent_var(envp, num_envp, &i,
-                           buffer, buffer_size, &length,
-                           "DEVICE=/proc/bus/usb/%03d/%03d",
+        if (add_uevent_var(env, "DEVICE=/proc/bus/usb/%03d/%03d",
                            usb_dev->bus->busnum, usb_dev->devnum))
                 return -ENOMEM;
 #endif
 
-        if (add_uevent_var(envp, num_envp, &i,
-                           buffer, buffer_size, &length,
-                           "PRODUCT=%x/%x/%x",
+        if (add_uevent_var(env, "PRODUCT=%x/%x/%x",
                            le16_to_cpu(usb_dev->descriptor.idVendor),
                            le16_to_cpu(usb_dev->descriptor.idProduct),
                            le16_to_cpu(usb_dev->descriptor.bcdDevice)))
                 return -ENOMEM;
 
-        if (add_uevent_var(envp, num_envp, &i,
-                           buffer, buffer_size, &length,
-                           "TYPE=%d/%d/%d",
+        if (add_uevent_var(env, "TYPE=%d/%d/%d",
                            usb_dev->descriptor.bDeviceClass,
                            usb_dev->descriptor.bDeviceSubClass,
                            usb_dev->descriptor.bDeviceProtocol))
                 return -ENOMEM;
 
-        if (add_uevent_var(envp, num_envp, &i,
-                   buffer, buffer_size, &length,
-                   "INTERFACE=%d/%d/%d",
+        if (add_uevent_var(env, "INTERFACE=%d/%d/%d",
                    alt->desc.bInterfaceClass,
                    alt->desc.bInterfaceSubClass,
                    alt->desc.bInterfaceProtocol))
                 return -ENOMEM;
 
-        if (add_uevent_var(envp, num_envp, &i,
-                   buffer, buffer_size, &length,
+        if (add_uevent_var(env,
                    "MODALIAS=usb:v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02Xic%02Xisc%02Xip%02X",
                    le16_to_cpu(usb_dev->descriptor.idVendor),
                    le16_to_cpu(usb_dev->descriptor.idProduct),
@@ -1404,14 +1392,12 @@ static int usb_if_uevent(struct device *dev, char **envp, int num_envp,
                    alt->desc.bInterfaceProtocol))
                 return -ENOMEM;
 
-        envp[i] = NULL;
         return 0;
 }
 
 #else
 
-static int usb_if_uevent(struct device *dev, char **envp,
-                         int num_envp, char *buffer, int buffer_size)
+static int usb_if_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
         return -ENODEV;
 }