No, the for loop is correct. Fisher-Yates shuffles algorithm is as follow:
-- To shuffle an array a of n elements (indices 0..n-1):
for i from n−1 downto 1 do
j random integer such that 0 <= j <= i
exchange a[j] and a[i]
https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle
On Mon, Jun 6, 2016 at 12:52 PM, Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:
> Hello Thomas Garnier,
>
> The patch aded650eb82e: "mm: reorganize SLAB freelist randomization"
> from Jun 5, 2016, leads to the following static checker warning:
>
> mm/slab_common.c:1160 freelist_randomize()
> warn: why is zero skipped 'i'
>
> mm/slab_common.c
> 1146 /* Randomize a generic freelist */
> 1147 static void freelist_randomize(struct rnd_state *state, unsigned int *list,
> 1148 size_t count)
> 1149 {
> 1150 size_t i;
> 1151 unsigned int rand;
> 1152
> 1153 for (i = 0; i < count; i++)
> 1154 list[i] = i;
> 1155
> 1156 /* Fisher-Yates shuffle */
> 1157 for (i = count - 1; i > 0; i--) {
>
> This looks like it should be i >= 0.
>
> 1158 rand = prandom_u32_state(state);
> 1159 rand %= (i + 1);
> 1160 swap(list[i], list[rand]);
> 1161 }
> 1162 }
>
> regards,
> dan carpenter
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