Re: [PATCH 1/4] EDAC: Fix calculation of returned address and next offset in edac_align_ptr()
From: Borislav Petkov
Date: Tue Jan 25 2022 - 09:41:13 EST
On Thu, Jan 13, 2022 at 10:06:19AM +0000, Eliav Farber wrote:
> Do alignment logic properly and use 'ptr' for calculating the remainder
> of the alignment.
>
> This became an issue because 'struct edac_mc_layer' has a size that is
> not zero modulo eight, and the next offset that was prepared for the
> private-data was unaligned, causing an alignment exception.
How exactly did this "become an issue"?
I'm asking because I have been hearing about weird bugs with that
pointer alignment contraption and have never managed to reproduce them
myself or hear a proper explanation from people.
And that thing is an abomination, frankly, and I'd like to get rid of it
but maybe some other time...
So, please explain more verbosely, a specific example or how I could
reproduce it, would be even better.
Thx.
--
Regards/Gruss,
Boris.
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