[PATCH v1 1/1] usb: gadget: Move kstrtox() out of lock

From: Andy Shevchenko
Date: Fri Jan 20 2023 - 13:27:57 EST


The kstrtox() calls operate on local (to the function) variables and do
not need to be serialized. We may call them out of the lock.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/usb/gadget/configfs.c | 72 +++++++++++++++++------------------
1 file changed, 36 insertions(+), 36 deletions(-)

diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c
index 78e7353e397b..63dc15b4f6d8 100644
--- a/drivers/usb/gadget/configfs.c
+++ b/drivers/usb/gadget/configfs.c
@@ -808,15 +808,15 @@ static ssize_t webusb_use_store(struct config_item *item, const char *page,
int ret;
bool use;

- mutex_lock(&gi->lock);
ret = kstrtobool(page, &use);
- if (!ret) {
- gi->use_webusb = use;
- ret = len;
- }
+ if (ret)
+ return ret;
+
+ mutex_lock(&gi->lock);
+ gi->use_webusb = use;
mutex_unlock(&gi->lock);

- return ret;
+ return len;
}

static ssize_t webusb_bcdVersion_show(struct config_item *item, char *page)
@@ -832,10 +832,12 @@ static ssize_t webusb_bcdVersion_store(struct config_item *item,
u16 bcdVersion;
int ret;

- mutex_lock(&gi->lock);
ret = kstrtou16(page, 0, &bcdVersion);
if (ret)
- goto out;
+ return ret;
+
+ mutex_lock(&gi->lock);
+
ret = is_valid_bcd(bcdVersion);
if (ret)
goto out;
@@ -862,15 +864,15 @@ static ssize_t webusb_bVendorCode_store(struct config_item *item,
int ret;
u8 b_vendor_code;

- mutex_lock(&gi->lock);
ret = kstrtou8(page, 0, &b_vendor_code);
- if (!ret) {
- gi->b_webusb_vendor_code = b_vendor_code;
- ret = len;
- }
+ if (ret)
+ return ret;
+
+ mutex_lock(&gi->lock);
+ gi->b_webusb_vendor_code = b_vendor_code;
mutex_unlock(&gi->lock);

- return ret;
+ return len;
}

static ssize_t webusb_landingPage_show(struct config_item *item, char *page)
@@ -956,15 +958,15 @@ static ssize_t os_desc_use_store(struct config_item *item, const char *page,
int ret;
bool use;

- mutex_lock(&gi->lock);
ret = kstrtobool(page, &use);
- if (!ret) {
- gi->use_os_desc = use;
- ret = len;
- }
+ if (ret)
+ return ret;
+
+ mutex_lock(&gi->lock);
+ gi->use_os_desc = use;
mutex_unlock(&gi->lock);

- return ret;
+ return len;
}

static ssize_t os_desc_b_vendor_code_show(struct config_item *item, char *page)
@@ -980,15 +982,15 @@ static ssize_t os_desc_b_vendor_code_store(struct config_item *item,
int ret;
u8 b_vendor_code;

- mutex_lock(&gi->lock);
ret = kstrtou8(page, 0, &b_vendor_code);
- if (!ret) {
- gi->b_vendor_code = b_vendor_code;
- ret = len;
- }
+ if (ret)
+ return ret;
+
+ mutex_lock(&gi->lock);
+ gi->b_vendor_code = b_vendor_code;
mutex_unlock(&gi->lock);

- return ret;
+ return len;
}

static ssize_t os_desc_qw_sign_show(struct config_item *item, char *page)
@@ -1113,15 +1115,15 @@ static ssize_t ext_prop_type_store(struct config_item *item,
u8 type;
int ret;

- if (desc->opts_mutex)
- mutex_lock(desc->opts_mutex);
ret = kstrtou8(page, 0, &type);
if (ret)
- goto end;
- if (type < USB_EXT_PROP_UNICODE || type > USB_EXT_PROP_UNICODE_MULTI) {
- ret = -EINVAL;
- goto end;
- }
+ return ret;
+
+ if (type < USB_EXT_PROP_UNICODE || type > USB_EXT_PROP_UNICODE_MULTI)
+ return -EINVAL;
+
+ if (desc->opts_mutex)
+ mutex_lock(desc->opts_mutex);

if ((ext_prop->type == USB_EXT_PROP_BINARY ||
ext_prop->type == USB_EXT_PROP_LE32 ||
@@ -1138,12 +1140,10 @@ static ssize_t ext_prop_type_store(struct config_item *item,
type == USB_EXT_PROP_BE32))
ext_prop->data_len >>= 1;
ext_prop->type = type;
- ret = len;

-end:
if (desc->opts_mutex)
mutex_unlock(desc->opts_mutex);
- return ret;
+ return len;
}

static ssize_t ext_prop_data_show(struct config_item *item, char *page)
--
2.39.0