Messages in this thread |  | | Date | Wed, 29 Jul 2020 10:28:14 +0800 | From | Kent Gibson <> | Subject | Re: [PATCH v2 05/18] gpiolib: cdev: support GPIO_GET_LINE_IOCTL and GPIOLINE_GET_VALUES_IOCTL |
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On Sun, Jul 26, 2020 at 09:12:44AM +0800, Kent Gibson wrote: > On Sat, Jul 25, 2020 at 11:51:54PM +0300, Andy Shevchenko wrote: > > On Sat, Jul 25, 2020 at 7:24 AM Kent Gibson <warthog618@gmail.com> wrote: > > >
[ snip ]
> > > + test_bit(line_idx, (unsigned long *)lc->attrs[i].mask)) > > > > This casting is not good. What about BE 32-bit architecture? > > > > I agree the casting is hideous, but I thought the outcome was correct > as it is manipulating addresses, not data. > You think the address of a 64-bit differs based on endian?? > Happy to change it - but not sure what to. >
You are right - using bitops on u64 is problematic for BE-32 - the 32-bit words will be swapped if userspace treats the flags as the u64 it is defined as.
I'll rework that for v3.
Cheers, Kent.
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