Re: [PATCH] x86, efi: Fix unaligned access and endian issues

[H. Peter Anvin]

On 02/22/2012 08:44 AM, Nick Bowler wrote:
> On 2012-02-22 14:00 +0000, Matt Fleming wrote:
> > From: Matt Fleming<matt.fleming@xxxxxxxxx>
> >
> > We need to read from and write to 'buf' a byte at a time otherwise
> > it's possible we'll perform an unaligned access, which can lead to a
> > segfault when cross-building an x86 kernel on risc architectures.
> >
> > Also, we may need to convert the endianness of the data we read
> > from/write to buf, so let's add some helper functions to do that.
> [...]
> > +static inline u32 read32_le(u8 *src)
> > +{
> > +	u32 data;
> > +
> > +	data = *src++;
> > +	data |= *src++<<  8;
> > +	data |= *src++<<  16;
> > +	data |= *src++<<  24;
> > +
> > +	return data;
> > +}
>
> We already have get_unaligned_le32 in<asm/unaligned.h>  for this.
>
> > +
> > +static inline void write32_le(u8 *dst, u32 data)
> > +{
> > +	*dst++ = data;
> > +	*dst++ = data>>  8;
> > +	*dst++ = data>>  16;
> > +	*dst++ = data>>  24;
> > +}
>
> Similarly, put_unaligned_le32.

This is user space; those headers are not exported.  However, sticking 
to the same name would be good.

I'm wondering if this is the kind of things that should be put in 
usr/include?

	-hpa


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