[PATCH 4.19 24/43] USB: replace hardcode maximum usb string length by definition

Greg Kroah-Hartman
2021-03-22T13:03:16Z

From: Macpaul Lin <macpaul.lin@mediatek.com>

commit 81c7462883b0cc0a4eeef0687f80ad5b5baee5f6 upstream.

Replace hardcoded maximum USB string length (126 bytes) by definition
"USB_MAX_STRING_LEN".

Signed-off-by: Macpaul Lin <macpaul.lin@mediatek.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/1592471618-29428-1-git-send-email-macpaul.lin@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/usb/gadget/composite.c | 4 ++--
drivers/usb/gadget/configfs.c | 2 +-
drivers/usb/gadget/usbstring.c | 4 ++--
include/uapi/linux/usb/ch9.h | 3 +++
4 files changed, 8 insertions(+), 5 deletions(-)

--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -1077,7 +1077,7 @@ static void collect_langs(struct usb_gad
while (*sp) {
s = *sp;
language = cpu_to_le16(s->language);
- for (tmp = buf; *tmp && tmp < &buf[126]; tmp++) {
+ for (tmp = buf; *tmp && tmp < &buf[USB_MAX_STRING_LEN]; tmp++) {
if (*tmp == language)
goto repeat;
}
@@ -1152,7 +1152,7 @@ static int get_string(struct usb_composi
collect_langs(sp, s->wData);
}

- for (len = 0; len <= 126 && s->wData[len]; len++)
+ for (len = 0; len <= USB_MAX_STRING_LEN && s->wData[len]; len++)
continue;
if (!len)
return -EINVAL;
--- a/drivers/usb/gadget/configfs.c
+++ b/drivers/usb/gadget/configfs.c
@@ -115,7 +115,7 @@ static int usb_string_copy(const char *s
char *str;
char *copy = *s_copy;
ret = strlen(s);
- if (ret > 126)
+ if (ret > USB_MAX_STRING_LEN)
return -EOVERFLOW;

str = kstrdup(s, GFP_KERNEL);
--- a/drivers/usb/gadget/usbstring.c
+++ b/drivers/usb/gadget/usbstring.c
@@ -55,9 +55,9 @@ usb_gadget_get_string (const struct usb_
return -EINVAL;

/* string descriptors have length, tag, then UTF16-LE text */
- len = min ((size_t) 126, strlen (s->s));
+ len = min((size_t)USB_MAX_STRING_LEN, strlen(s->s));
len = utf8s_to_utf16s(s->s, len, UTF16_LITTLE_ENDIAN,
- (wchar_t *) &buf[2], 126);
+ (wchar_t *) &buf[2], USB_MAX_STRING_LEN);
if (len < 0)
return -EINVAL;
buf [0] = (len + 1) * 2;
--- a/include/uapi/linux/usb/ch9.h
+++ b/include/uapi/linux/usb/ch9.h
@@ -364,6 +364,9 @@ struct usb_config_descriptor {

/*-------------------------------------------------------------------------*/

+/* USB String descriptors can contain at most 126 characters. */
+#define USB_MAX_STRING_LEN 126
+
/* USB_DT_STRING: String descriptor */
struct usb_string_descriptor {
__u8 bLength;