Re: [GIT PULL] siginfo fix for v4.16-rc5

[Josh Juran]

On Apr 3, 2018, at 10:27 AM, Eric W. Biederman <ebiederm@xxxxxxxxxxxx> wrote:

> Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> writes:
> 
>> On Mon, Apr 2, 2018 at 10:17 PM, Eric W. Biederman <ebiederm@xxxxxxxxxxxx> wrote:
>> 
>>> A 2-byte alignment for 4 byte pointers.  That is a new one to me.
>> 
>> Not just for pointers, also for int and long.
> 
> The smallest I have seen previously has been 64bit integers having
> 32bit alignment.  32bit entities having only 16bit alignment on a 32bit
> arch was simply a surprise.  Even when it works there tend to be good
> reasons not to do that by default.

The 68K architecture began as 16-bit with the 68000.  Rather than tightening requirements, the 68020 not only maintained compatibility with 16-bit alignment, but also forgave byte-misaligned data accesses (albeit with a performance penalty).  Jumping to an odd address is still an error, though.

Josh