From: Pavel Skripkin

Sent: 26 August 2021 10:28

On 8/26/21 12:22 PM, Pavel Skripkin wrote:

quoted

On Thu, 26 Aug 2021 08:51:23 +0000
David Laight [off-list ref] wrote:

...

quoted

quoted

...

quoted

-static u32 usb_read32(struct intf_hdl *pintfhdl, u32 addr)
+static int usb_read32(struct intf_hdl *pintfhdl, u32 addr, u32
*data) {
 	u8 requesttype;
 	u16 wvalue;
 	u16 len;
-	__le32 data;
+	int res;
+	__le32 tmp;
+
+	if (WARN_ON(unlikely(!data)))
+		return -EINVAL;

Kill the NULL check - it is a silly coding error.
An OOPS is just as easy to debug.

I don't think that one single driver should kill the whole system. It's
100% an error, but kernel can recover from it (for example disconnect
the driver, since it's broken).


AFIAK, Greg and Linus do not like BUG_ONs in recoverable state...
Correct me, if I am wrong

Oops, I thought about BUG_ON() instead of WARN_ON(), sorry for
confusion. My point is "we should not let the box boom".

There is no point checking for NULL that just can't happen.
In this case all the callers will pass the address of a local.
There really is no point checking.

	David

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