m68k: bitops - Never step beyond the end of the bitmap
m68k: bitops - Never step beyond the end of the bitmap

find_next bitops on m68k (find_next_zero_bit, find_next_bit, and
find_next_bit_le) may cause out of bounds memory access
when the bitmap size in bits % 32 != 0 and offset (the bitnumber
to start searching at) is very close to the bitmap size.

For example,

       unsigned long bitmap[2] = { 0, 0 };
       find_next_bit(bitmap, 63, 62);

1. find_next_bit() tries to find any set bits in bitmap[1],
   but no bits set.

2. Then find_first_bit(bimap + 2, -1)

3. Unfortunately find_first_bit() takes unsigned int as the size argument.

4. find_first_bit will access bitmap[2~] until it find any set bits.

Add missing tests for stepping beyond the end of the bitmap to all
find_{first,next}_*() functions, and make sure they never return a value
larger than the bitmap size.

Reported-by: Akinobu Mita <3807cf899f217da549814bf6c330d3b6e6819ccf@gmail.com>
Cc: Andreas Schwab <c9df6394cb541f693236245820fbe23866f1a3fe@linux-m68k.org>
Signed-off-by: Geert Uytterhoeven <0da414d9d963da4039c2a0525b1844228075aa58@linux-m68k.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs