usb: gadget: printer: Remove pnp_string static buffer

pnp string is usually much shorter than 1k so let's stop wasting 1k of
memory for its buffer and make it dynamically alocated.
This also removes 1k len limitation for pnp_string and
adds a new line after string content if required.

Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

diff --git a/drivers/usb/gadget/function/f_printer.c b/drivers/usb/gadget/function/f_printer.c
index 8054da9276dd90afc6a38fb9c69e7771c7c25d59..8df244fc9d80daa4c7caf0da729bae2ac66137a2 100644 (file)
--- a/drivers/usb/gadget/function/f_printer.c
+++ b/drivers/usb/gadget/function/f_printer.c
@@ -49,7 +49,6 @@
 
 #include "u_printer.h"
 
-#define PNP_STRING_LEN         1024
 #define PRINTER_MINORS         4
 #define GET_DEVICE_ID          0
 #define GET_PORT_STATUS                1
@@ -907,8 +906,7 @@ static bool gprinter_req_match(struct usb_function *f,
        switch (ctrl->bRequest) {
        case GET_DEVICE_ID:
                w_index >>= 8;
-               if (w_length <= PNP_STRING_LEN &&
-                   (USB_DIR_IN & ctrl->bRequestType))
+               if (USB_DIR_IN & ctrl->bRequestType)
                        break;
                return false;
        case GET_PORT_STATUS:
@@ -937,6 +935,7 @@ static int printer_func_setup(struct usb_function *f,
        struct printer_dev *dev = func_to_printer(f);
        struct usb_composite_dev *cdev = f->config->cdev;
        struct usb_request      *req = cdev->req;
+       u8                      *buf = req->buf;
        int                     value = -EOPNOTSUPP;
        u16                     wIndex = le16_to_cpu(ctrl->wIndex);
        u16                     wValue = le16_to_cpu(ctrl->wValue);
@@ -953,10 +952,16 @@ static int printer_func_setup(struct usb_function *f,
                        if ((wIndex>>8) != dev->interface)
                                break;
 
-                       value = (dev->pnp_string[0] << 8) | dev->pnp_string[1];
-                       memcpy(req->buf, dev->pnp_string, value);
+                       if (!dev->pnp_string) {
+                               value = 0;
+                               break;
+                       }
+                       value = strlen(dev->pnp_string);
+                       buf[0] = (value >> 8) & 0xFF;
+                       buf[1] = value & 0xFF;
+                       memcpy(buf + 2, dev->pnp_string, value);
                        DBG(dev, "1284 PNP String: %x %s\n", value,
-                                       &dev->pnp_string[2]);
+                           dev->pnp_string);
                        break;
 
                case GET_PORT_STATUS: /* Get Port Status */
@@ -964,7 +969,7 @@ static int printer_func_setup(struct usb_function *f,
                        if (wIndex != dev->interface)
                                break;
 
-                       *(u8 *)req->buf = dev->printer_status;
+                       buf[0] = dev->printer_status;
                        value = min_t(u16, wLength, 1);
                        break;
 
@@ -1157,10 +1162,21 @@ static ssize_t f_printer_opts_pnp_string_show(struct config_item *item,
                                              char *page)
 {
        struct f_printer_opts *opts = to_f_printer_opts(item);
-       int result;
+       int result = 0;
 
        mutex_lock(&opts->lock);
-       result = strlcpy(page, opts->pnp_string + 2, PNP_STRING_LEN - 2);
+       if (!opts->pnp_string)
+               goto unlock;
+
+       result = strlcpy(page, opts->pnp_string, PAGE_SIZE);
+       if (result >= PAGE_SIZE) {
+               result = PAGE_SIZE;
+       } else if (page[result - 1] != '\n' && result + 1 < PAGE_SIZE) {
+               page[result++] = '\n';
+               page[result] = '\0';
+       }
+
+unlock:
        mutex_unlock(&opts->lock);
 
        return result;
@@ -1170,13 +1186,24 @@ static ssize_t f_printer_opts_pnp_string_store(struct config_item *item,
                                               const char *page, size_t len)
 {
        struct f_printer_opts *opts = to_f_printer_opts(item);
-       int result, l;
+       char *new_pnp;
+       int result;
 
        mutex_lock(&opts->lock);
-       result = strlcpy(opts->pnp_string + 2, page, PNP_STRING_LEN - 2);
-       l = strlen(opts->pnp_string + 2) + 2;
-       opts->pnp_string[0] = (l >> 8) & 0xFF;
-       opts->pnp_string[1] = l & 0xFF;
+
+       new_pnp = kstrndup(page, len, GFP_KERNEL);
+       if (!new_pnp) {
+               result = -ENOMEM;
+               goto unlock;
+       }
+
+       if (opts->pnp_string_allocated)
+               kfree(opts->pnp_string);
+
+       opts->pnp_string_allocated = true;
+       opts->pnp_string = new_pnp;
+       result = len;
+unlock:
        mutex_unlock(&opts->lock);
 
        return result;
@@ -1270,6 +1297,8 @@ static void gprinter_free_inst(struct usb_function_instance *f)
 
        mutex_unlock(&printer_ida_lock);
 
+       if (opts->pnp_string_allocated)
+               kfree(opts->pnp_string);
        kfree(opts);
 }
 

diff --git a/drivers/usb/gadget/function/u_printer.h b/drivers/usb/gadget/function/u_printer.h
index 0e2c49d4274e403390c37d17358caefb733fcade..8d30b7577f877284a9b366e22b5f993016e2df18 100644 (file)
--- a/drivers/usb/gadget/function/u_printer.h
+++ b/drivers/usb/gadget/function/u_printer.h
@@ -18,12 +18,11 @@
 
 #include <linux/usb/composite.h>
 
-#define PNP_STRING_LEN                 1024
-
 struct f_printer_opts {
        struct usb_function_instance    func_inst;
        int                             minor;
-       char                            pnp_string[PNP_STRING_LEN];
+       char                            *pnp_string;
+       bool                            pnp_string_allocated;
        unsigned                        q_len;
 
        /*

diff --git a/drivers/usb/gadget/legacy/printer.c b/drivers/usb/gadget/legacy/printer.c
index 6f969a86175c31a69cdf01b49b8bba8b6169b8f3..4c9cfff34a03fde35060c559b4a67ce6c34ecaf9 100644 (file)
--- a/drivers/usb/gadget/legacy/printer.c
+++ b/drivers/usb/gadget/legacy/printer.c
@@ -88,8 +88,8 @@ static const struct usb_descriptor_header *otg_desc[2];
 
 static char                            product_desc [40] = DRIVER_DESC;
 static char                            serial_num [40] = "1";
-static char                            pnp_string[PNP_STRING_LEN] =
-       "XXMFG:linux;MDL:g_printer;CLS:PRINTER;SN:1;";
+static char                            *pnp_string =
+       "MFG:linux;MDL:g_printer;CLS:PRINTER;SN:1;";
 
 /* static strings, in UTF-8 */
 static struct usb_string               strings [] = {
@@ -143,23 +143,29 @@ static int printer_do_config(struct usb_configuration *c)
 static int printer_bind(struct usb_composite_dev *cdev)
 {
        struct f_printer_opts *opts;
-       int ret, len;
+       int ret;
 
        fi_printer = usb_get_function_instance("printer");
        if (IS_ERR(fi_printer))
                return PTR_ERR(fi_printer);
 
-       if (iPNPstring)
-               strlcpy(&pnp_string[2], iPNPstring, PNP_STRING_LEN - 2);
-
-       len = strlen(pnp_string);
-       pnp_string[0] = (len >> 8) & 0xFF;
-       pnp_string[1] = len & 0xFF;
-
        opts = container_of(fi_printer, struct f_printer_opts, func_inst);
        opts->minor = 0;
-       memcpy(opts->pnp_string, pnp_string, PNP_STRING_LEN);
        opts->q_len = QLEN;
+       if (iPNPstring) {
+               opts->pnp_string = kstrdup(iPNPstring, GFP_KERNEL);
+               if (!opts->pnp_string) {
+                       ret = -ENOMEM;
+                       goto fail_put_func_inst;
+               }
+               opts->pnp_string_allocated = true;
+               /*
+                * we don't free this memory in case of error
+                * as printer cleanup func will do this for us
+                */
+       } else {
+               opts->pnp_string = pnp_string;
+       }
 
        ret = usb_string_ids_tab(cdev, strings);
        if (ret < 0)