random: eliminate redundant new_rotate variable (feee7697) · Commits · 戴 / test

drivers/char/random.c

+10 −12

Original line number	Diff line number	Diff line
		@@ -455,7 +455,7 @@ static void __add_entropy_words(struct entropy_store r, const __u32 in,
		0x00000000, 0x3b6e20c8, 0x76dc4190, 0x4db26158,
		0xedb88320, 0xd6d6a3e8, 0x9b64c2b0, 0xa00ae278 };
		unsigned long i, add_ptr, tap1, tap2, tap3, tap4, tap5;
		int new_rotate, input_rotate;
		int input_rotate;
		int wordmask = r->poolinfo->poolwords - 1;
		__u32 w, next_w;
		unsigned long flags;
		@@ -474,20 +474,10 @@ static void __add_entropy_words(struct entropy_store r, const __u32 in,
		add_ptr = r->add_ptr;

		while (nwords--) {
		w = rol32(next_w, input_rotate);
		w = rol32(next_w, input_rotate & 31);
		if (nwords > 0)
		next_w = *in++;
		i = add_ptr = (add_ptr - 1) & wordmask;
		/*
		* Normally, we add 7 bits of rotation to the pool.
		* At the beginning of the pool, add an extra 7 bits
		* rotation, so that successive passes spread the
		* input bits across the pool evenly.
		*/
		new_rotate = input_rotate + 14;
		if (i)
		new_rotate = input_rotate + 7;
		input_rotate = new_rotate & 31;

		/* XOR in the various taps */
		w ^= r->pool[(i + tap1) & wordmask];
		@@ -497,6 +487,14 @@ static void __add_entropy_words(struct entropy_store r, const __u32 in,
		w ^= r->pool[(i + tap5) & wordmask];
		w ^= r->pool[i];
		r->pool[i] = (w >> 3) ^ twist_table[w & 7];

		/*
		* Normally, we add 7 bits of rotation to the pool.
		* At the beginning of the pool, add an extra 7 bits
		* rotation, so that successive passes spread the
		* input bits across the pool evenly.
		*/
		input_rotate += i ? 7 : 14;
		}

		r->input_rotate = input_rotate;