Re: [PATCH] usb: core: Do not use sizeof on pointer type

From: Clemens Ladisch
Date: Fri Apr 22 2016 - 02:53:45 EST


Vaishali Thakkar wrote:
> When sizeof is applied to a pointer typed expression, it gives
> the size of the pointer.

And why would that be wrong in this case?

> +++ b/drivers/usb/core/hcd.c
> @@ -1386,7 +1386,7 @@ static int hcd_alloc_coherent(struct usb_bus *bus,
> return -EFAULT;
> }
>
> - vaddr = hcd_buffer_alloc(bus, size + sizeof(vaddr),
> + vaddr = hcd_buffer_alloc(bus, size + sizeof(*vaddr),
> mem_flags, dma_handle);
> if (!vaddr)
> return -ENOMEM;
>

Please note the following comment:

/*
* Store the virtual address of the buffer at the end
* of the allocated dma buffer. [...]


Regards,
Clemens