This reverts commit 86b20af11e84c26ae3fde4dcc4f490948e3f8035.
This patch leads to passing 0 to simple_read_from_buffer()
as a fifth argument, turning the read method into a nop.
The change is fundamentally flawed, as it breaks the driver.
Signed-off-by: Oliver Neukum <oneukum@xxxxxxxx>
---
drivers/usb/misc/yurex.c | 19 ++++++++-----------
1 file changed, 8 insertions(+), 11 deletions(-)
diff --git a/drivers/usb/misc/yurex.c b/drivers/usb/misc/yurex.c
index 316634f782c6..bd94bf078de3 100644
--- a/drivers/usb/misc/yurex.c
+++ b/drivers/usb/misc/yurex.c
@@ -34,8 +34,6 @@
#define YUREX_BUF_SIZE 8
#define YUREX_WRITE_TIMEOUT (HZ*2)
-#define MAX_S64_STRLEN 20 /* {-}922337203685477580{7,8} */
-
/* table of devices that work with this driver */
static struct usb_device_id yurex_table[] = {
{ USB_DEVICE(YUREX_VENDOR_ID, YUREX_PRODUCT_ID) },
@@ -403,7 +401,8 @@ static ssize_t yurex_read(struct file *file, char __user *buffer, size_t count,
{
struct usb_yurex *dev;
int len = 0;
- char in_buffer[MAX_S64_STRLEN];
+ char in_buffer[20];
+ unsigned long flags;
dev = file->private_data;
@@ -413,16 +412,14 @@ static ssize_t yurex_read(struct file *file, char __user *buffer, size_t count,
return -ENODEV;
}
- if (WARN_ON_ONCE(dev->bbu > S64_MAX || dev->bbu < S64_MIN)) {
- mutex_unlock(&dev->io_mutex);
- return -EIO;
- }
-
- spin_lock_irq(&dev->lock);
- scnprintf(in_buffer, MAX_S64_STRLEN, "%lld\n", dev->bbu);
- spin_unlock_irq(&dev->lock);
+ spin_lock_irqsave(&dev->lock, flags);
+ len = snprintf(in_buffer, 20, "%lld\n", dev->bbu);
+ spin_unlock_irqrestore(&dev->lock, flags);
mutex_unlock(&dev->io_mutex);
+ if (WARN_ON_ONCE(len >= sizeof(in_buffer)))
+ return -EIO;
+
return simple_read_from_buffer(buffer, count, ppos, in_buffer, len);
}
--
2.46.1
