From fdc01cc286be9d32140631469b7608f3f58c2db3 Mon Sep 17 00:00:00 2001
From: Krzysztof Opasiak <k.opasiak@samsung.com>
Date: Wed, 21 Dec 2016 09:48:45 +0100
Subject: [PATCH] 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>
---
drivers/usb/gadget/function/f_printer.c | 57 +++++++++++++++++++------
drivers/usb/gadget/function/u_printer.h | 5 +--
drivers/usb/gadget/legacy/printer.c | 28 +++++++-----
3 files changed, 62 insertions(+), 28 deletions(-)
diff --git a/drivers/usb/gadget/function/f_printer.c b/drivers/usb/gadget/function/f_printer.c
index 8054da9276dd9..8df244fc9d80d 100644
--- 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 0e2c49d4274e4..8d30b7577f877 100644
--- 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 6f969a86175c3..4c9cfff34a03f 100644
--- 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)
--
2.30.2