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Re: Help needed to debug an armel build/unittest failure



On 3/11/10, Martin Guy <martinwguy@gmail.com> wrote:

>  You can test for that by going
>   # echo 5 > /proc/cpu/alignment
>  and running your test again. On unaligned access the program will then
>  die with SIGBUS instead of merrily going on its way with corrupted
>  values.

Note that QEMU does not emulate either the unaligned data corruption
on /proc/cpu/alignment=0 nor the bus error on /proc/cpu/alignment=5;
it always (on x86) performs a fixup, fetching in the "usual" way from
*p to *[p+3], presumably because it compiles to an x86 word fetch.
Real hardware is needed to test for word alignment errors.

     M


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