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

Greg KH
2018-07-09T04:26:27Z

On Sun, Jul 08, 2018 at 09:45:31PM +0300, Алексей Бродкин wrote:
> 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?

Please resend it properly, it is not in my patch queue anywhere...

greg k-h