On Tue, 2019-10-15 at 13:46 -0500, Gustavo A. R. Silva wrote: > In expression 0xff << offset, left shifting by more than 31 bits has > undefined behavior. Notice that the shift amount, *offset*, can be as > much as 63. > > Fix this by adding suffix ULL to integer 0xFF. [] > diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h [] > @@ -520,7 +520,7 @@ static inline void bitmap_set_value8(unsigned long *map, > unsigned long value, > const size_t index = BIT_WORD(start); > const unsigned long offset = start % BITS_PER_LONG; > > - map[index] &= ~(0xFF << offset); > + map[index] &= ~(0xFFULL << offset);
BITS_PER_LONG is 32 and 0xFFULL is 64 bit when compiled for 32 bit arches. This should just be 0xFFUL and not ULL.
