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

From	Clemens Ladisch <clemens@ladisch.de>
Newsgroups	linux.kernel
Subject	Re: [PATCH] usb: core: Do not use sizeof on pointer type
Date	2016-04-22 09:00 +0200
Message-ID	<rqDei-697-17@gated-at.bofh.it> (permalink)
References	<rqCie-5m3-13@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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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

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[PATCH] usb: core: Do not use sizeof on pointer type Vaishali Thakkar <vaishali.thakkar@oracle.com> - 2016-04-22 08:00 +0200
  Re: [PATCH] usb: core: Do not use sizeof on pointer type Bjørn Mork <bjorn@mork.no> - 2016-04-22 09:00 +0200
  Re: [PATCH] usb: core: Do not use sizeof on pointer type Clemens Ladisch <clemens@ladisch.de> - 2016-04-22 09:00 +0200

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