Re: problems with memory allocation and the alignment check

[Andrew Pinski]

On Mon, Feb 22, 2021 at 1:17 AM Michael J. Baars
<mjbaars1977.gcc@xxxxxxxxxxxxx> wrote:
>
> Hi,
>
> I just wrote this little program to demonstrate a possible flaw in both malloc and calloc.
>
> If I allocate a the simplest memory region from main(), one out of three optimization flags fail.
> If I allocate the same region from a function, three out of three optimization flags fail.
>
> Does someone know if this really is a flaw, and if so, is it a gcc or a kernel flaw?

There is no flaw.  GCC (kernel, glibc) all assume unaligned accesses
on x86 will not cause an exception.

Thanks,
Andrew

>
> Regards,
> Mischa.