Re: [PATCH v2] devres: Really align data field to unsigned long long

Алексей Бродкин
2018-07-08T18:45:53Z

Hi Greg,

вс, 8 июл. 2018 г. в 21:40, Greg KH <greg@kroah.com>:
>
> On Sun, Jul 08, 2018 at 08:56:21PM +0300, Alexey Brodkin wrote:
> > Depending on ABI "long long" type of a particular 32-bit CPU
> > might be aligned by either word (32-bits) or double word (64-bits).
> > Make sure "data" is really 64-bit aligned for any 32-bit CPU.
> >
> > At least for 32-bit ARC cores ABI requires "long long" types
> > to be aligned by normal 32-bit word. This makes "data" field aligned to
> > 12 bytes. Which is still OK as long as we use 32-bit data only.
> >
> > But once we want to use native atomic64_t type (i.e. when we use special
> > instructions LLOCKD/SCONDD for accessing 64-bit data) we easily hit
> > misaligned access exception.
> >
> > That's because even on CPUs capable of non-aligned data access LL/SC
> > instructions require strict alignment.
> >
> > Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
> > Cc: Thomas Gleixner <tglx@linutronix.de>
> > Cc: stable@vger.kernel.org
> > ---
> >
> > Changes v1 -> v2:
> >
> > * Reworded commit message
> > * Inserted comment right in source [Thomas]
> >
> > drivers/base/devres.c | 8 ++++++--
> > 1 file changed, 6 insertions(+), 2 deletions(-)
>
> Always use scripts/get_maintainer.pl to properly cc: the needed
> developer/maintainer. As it is, this patch is going to get dropped on
> the floor, sorry...

Right I was way too relaxed dealing with very generic stuff which might get
not that much of attention as more narrow topics or subsystems. But anyways
get_maintainer.pl says you're the guy so do I need to do anything extra still or
it's OK for this time?

-Alexey