pinctrl: stmfx: Fix hazardous u8[] to unsigned long cast

Casting a small array of u8 to an unsigned long is *never* OK:

- it does funny thing when the array size is less than that of a long,
  as it accesses random places in the stack
- it makes everything even more fun with a BE kernel

Fix this by building the unsigned long used as a bitmap byte by byte,
in a way that works across endianess and has no undefined behaviours.

An extra BUILD_BUG_ON() catches the unlikely case where the array
would be larger than a single unsigned long.

Fixes: 1490d9f841b1 ("pinctrl: Add STMFX GPIO expander Pinctrl/GPIO driver")
Signed-off-by: Marc Zyngier <[email protected]>
Cc: [email protected]
Cc: Amelie Delaunay <[email protected]>
Cc: Linus Walleij <[email protected]>
Cc: Maxime Coquelin <[email protected]>
Cc: Alexandre Torgue <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Linus Walleij <[email protected]>

0 files changed, 0 insertions, 0 deletions