On Wed, Apr 29, 2020 at 08:40:40AM +0200, Ahmad Fatoum wrote: > On little endian platforms that don't define __arch_swab32p, be32_to_cpu > ultimately expands to an expression that evaluates its argument multiple > times. Because of the increment, this is wrong (and UB because of > unsequenced modification). > Hoist the side effect out of the macro argument.
I'm not sure if the reasoning is correct. That would mean that of_read_number() doesn't work on ARM, but I can assure it actually does. > > Signed-off-by: Ahmad Fatoum <[email protected]> > --- > include/of.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/include/of.h b/include/of.h > index 85d55f9b57dc..08bbeaf4d21b 100644 > --- a/include/of.h > +++ b/include/of.h > @@ -79,8 +79,8 @@ struct fdt_header *of_get_fixed_tree(struct device_node > *node); > static inline u64 of_read_number(const __be32 *cell, int size) > { > u64 r = 0; > - while (size--) > - r = (r << 32) | be32_to_cpu(*(cell++)); > + for (; size--; cell++) > + r = (r << 32) | be32_to_cpu(*cell); That said, the implementation looks way better with this patch. Sascha -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list [email protected] http://lists.infradead.org/mailman/listinfo/barebox
