Commit f743f16c authored by Jason A. Donenfeld's avatar Jason A. Donenfeld
Browse files

treewide: use get_random_{u8,u16}() when possible, part 2 



Rather than truncate a 32-bit value to a 16-bit value or an 8-bit value,
simply use the get_random_{u8,u16}() functions, which are faster than
wasting the additional bytes from a 32-bit value. This was done by hand,
identifying all of the places where one of the random integer functions
was used in a non-32-bit context.

Reviewed-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Reviewed-by: default avatarYury Norov <yury.norov@gmail.com>
Acked-by: default avatarJakub Kicinski <kuba@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390
Signed-off-by: default avatarJason A. Donenfeld <Jason@zx2c4.com>
parent 7e3cf084

arch/s390/kernel/process.c

+1 −1
Original line number Diff line number Diff line
@@ -230,7 +230,7 @@ unsigned long arch_align_stack(unsigned long sp) 


static inline unsigned long brk_rnd(void)

{

	return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT;

	return (get_random_u16() & BRK_RND_MASK) << PAGE_SHIFT;

}



unsigned long arch_randomize_brk(struct mm_struct *mm)

drivers/mtd/nand/raw/nandsim.c

+1 −1
Original line number Diff line number Diff line
@@ -1402,7 +1402,7 @@ static int ns_do_read_error(struct nandsim *ns, int num) 


static void ns_do_bit_flips(struct nandsim *ns, int num)

{

	if (bitflips && prandom_u32() < (1 << 22)) {

	if (bitflips && get_random_u16() < (1 << 6)) {

		int flips = 1;

		if (bitflips > 1)

			flips = prandom_u32_max(bitflips) + 1;

drivers/net/wireless/broadcom/brcm80211/brcmfmac/pno.c

+1 −1
Original line number Diff line number Diff line
@@ -177,7 +177,7 @@ static int brcmf_pno_set_random(struct brcmf_if *ifp, struct brcmf_pno_info *pi) 
	memcpy(pfn_mac.mac, mac_addr, ETH_ALEN);

	for (i = 0; i < ETH_ALEN; i++) {

		pfn_mac.mac[i] &= mac_mask[i];

		pfn_mac.mac[i] |= get_random_int() & ~(mac_mask[i]);

		pfn_mac.mac[i] |= get_random_u8() & ~(mac_mask[i]);

	}

	/* Clear multi bit */

	pfn_mac.mac[0] &= 0xFE;

lib/test_vmalloc.c

+1 −1
Original line number Diff line number Diff line
@@ -80,7 +80,7 @@ static int random_size_align_alloc_test(void) 
	int i;



	for (i = 0; i < test_loop_count; i++) {

		rnd = prandom_u32();

		rnd = get_random_u8();



		/*

		 * Maximum 1024 pages, if PAGE_SIZE is 4096.

net/rds/bind.c

+1 −1
Original line number Diff line number Diff line
@@ -104,7 +104,7 @@ static int rds_add_bound(struct rds_sock *rs, const struct in6_addr *addr, 
			return -EINVAL;

		last = rover;

	} else {

		rover = max_t(u16, prandom_u32(), 2);

		rover = max_t(u16, get_random_u16(), 2);

		last = rover - 1;

	}