Merge tag 'random-6.1-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random

Pull more random number generator updates from Jason Donenfeld:
 "This time with some large scale treewide cleanups.

  The intent of this pull is to clean up the way callers fetch random
  integers. The current rules for doing this right are:

   - If you want a secure or an insecure random u64, use get_random_u64()

   - If you want a secure or an insecure random u32, use get_random_u32()

     The old function prandom_u32() has been deprecated for a while
     now and is just a wrapper around get_random_u32(). Same for
     get_random_int().

   - If you want a secure or an insecure random u16, use get_random_u16()

   - If you want a secure or an insecure random u8, use get_random_u8()

   - If you want secure or insecure random bytes, use get_random_bytes().

     The old function prandom_bytes() has been deprecated for a while
     now and has long been a wrapper around get_random_bytes()

   - If you want a non-uniform random u32, u16, or u8 bounded by a
     certain open interval maximum, use prandom_u32_max()

     I say "non-uniform", because it doesn't do any rejection sampling
     or divisions. Hence, it stays within the prandom_*() namespace, not
     the get_random_*() namespace.

     I'm currently investigating a "uniform" function for 6.2. We'll see
     what comes of that.

  By applying these rules uniformly, we get several benefits:

   - By using prandom_u32_max() with an upper-bound that the compiler
     can prove at compile-time is ≤65536 or ≤256, internally
     get_random_u16() or get_random_u8() is used, which wastes fewer
     batched random bytes, and hence has higher throughput.

   - By using prandom_u32_max() instead of %, when the upper-bound is
     not a constant, division is still avoided, because
     prandom_u32_max() uses a faster multiplication-based trick instead.

   - By using get_random_u16() or get_random_u8() in cases where the
     return value is intended to indeed be a u16 or a u8, we waste fewer
     batched random bytes, and hence have higher throughput.

  This series was originally done by hand while I was on an airplane
  without Internet. Later, Kees and I worked on retroactively figuring
  out what could be done with Coccinelle and what had to be done
  manually, and then we split things up based on that.

  So while this touches a lot of files, the actual amount of code that's
  hand fiddled is comfortably small"

* tag 'random-6.1-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random:
  prandom: remove unused functions
  treewide: use get_random_bytes() when possible
  treewide: use get_random_u32() when possible
  treewide: use get_random_{u8,u16}() when possible, part 2
  treewide: use get_random_{u8,u16}() when possible, part 1
  treewide: use prandom_u32_max() when possible, part 2
  treewide: use prandom_u32_max() when possible, part 1

19 files changed, 33 insertions, 34 deletions

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 24bb50dfd362..e84c49bf4d0c 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -4806,7 +4806,7 @@ static u32 bond_rr_gen_slave_id(struct bonding *bond)
 
 	switch (packets_per_slave) {
 	case 0:
-		slave_id = prandom_u32();
+		slave_id = get_random_u32();
 		break;
 	case 1:
 		slave_id = this_cpu_inc_return(*bond->rr_tx_counter);
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index eed98c10ca9d..04cf7684f1b0 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -3874,7 +3874,7 @@ static void bnxt_init_vnics(struct bnxt *bp)
 
 		if (bp->vnic_info[i].rss_hash_key) {
 			if (i == 0)
-				prandom_bytes(vnic->rss_hash_key,
+				get_random_bytes(vnic->rss_hash_key,
 					      HW_HASH_KEY_SIZE);
 			else
 				memcpy(vnic->rss_hash_key,
diff --git a/drivers/net/ethernet/broadcom/cnic.c b/drivers/net/ethernet/broadcom/cnic.c
index e86503d97f32..2198e35d9e18 100644
--- a/drivers/net/ethernet/broadcom/cnic.c
+++ b/drivers/net/ethernet/broadcom/cnic.c
@@ -4105,8 +4105,7 @@ static int cnic_cm_alloc_mem(struct cnic_dev *dev)
 	for (i = 0; i < MAX_CM_SK_TBL_SZ; i++)
 		atomic_set(&cp->csk_tbl[i].ref_count, 0);
 
-	port_id = prandom_u32();
-	port_id %= CNIC_LOCAL_PORT_RANGE;
+	port_id = prandom_u32_max(CNIC_LOCAL_PORT_RANGE);
 	if (cnic_init_id_tbl(&cp->csk_port_tbl, CNIC_LOCAL_PORT_RANGE,
 			     CNIC_LOCAL_PORT_MIN, port_id)) {
 		cnic_cm_free_mem(dev);
@@ -4165,7 +4164,7 @@ static int cnic_cm_init_bnx2_hw(struct cnic_dev *dev)
 {
 	u32 seed;
 
-	seed = prandom_u32();
+	seed = get_random_u32();
 	cnic_ctx_wr(dev, 45, 0, seed);
 	return 0;
 }
diff --git a/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_cm.c b/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_cm.c
index f90bfba4b303..c2e7037c7ba1 100644
--- a/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_cm.c
+++ b/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_cm.c
@@ -1063,7 +1063,7 @@ static void chtls_pass_accept_rpl(struct sk_buff *skb,
 	opt2 |= WND_SCALE_EN_V(WSCALE_OK(tp));
 	rpl5->opt0 = cpu_to_be64(opt0);
 	rpl5->opt2 = cpu_to_be32(opt2);
-	rpl5->iss = cpu_to_be32((prandom_u32() & ~7UL) - 1);
+	rpl5->iss = cpu_to_be32((get_random_u32() & ~7UL) - 1);
 	set_wr_txq(skb, CPL_PRIORITY_SETUP, csk->port_id);
 	t4_set_arp_err_handler(skb, sk, chtls_accept_rpl_arp_failure);
 	cxgb4_l2t_send(csk->egress_dev, skb, csk->l2t_entry);
@@ -1466,7 +1466,7 @@ static void make_established(struct sock *sk, u32 snd_isn, unsigned int opt)
 	tp->write_seq = snd_isn;
 	tp->snd_nxt = snd_isn;
 	tp->snd_una = snd_isn;
-	inet_sk(sk)->inet_id = prandom_u32();
+	inet_sk(sk)->inet_id = get_random_u16();
 	assign_rxopt(sk, opt);
 
 	if (tp->rcv_wnd > (RCV_BUFSIZ_M << 10))
diff --git a/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_io.c b/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_io.c
index 539992dad8ba..a4256087ac82 100644
--- a/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_io.c
+++ b/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_io.c
@@ -919,8 +919,8 @@ static int csk_wait_memory(struct chtls_dev *cdev,
 	current_timeo = *timeo_p;
 	noblock = (*timeo_p ? false : true);
 	if (csk_mem_free(cdev, sk)) {
-		current_timeo = (prandom_u32() % (HZ / 5)) + 2;
-		vm_wait = (prandom_u32() % (HZ / 5)) + 2;
+		current_timeo = prandom_u32_max(HZ / 5) + 2;
+		vm_wait = prandom_u32_max(HZ / 5) + 2;
 	}
 
 	add_wait_queue(sk_sleep(sk), &wait);
diff --git a/drivers/net/ethernet/rocker/rocker_main.c b/drivers/net/ethernet/rocker/rocker_main.c
index 023682cd2768..9e59669a93dd 100644
--- a/drivers/net/ethernet/rocker/rocker_main.c
+++ b/drivers/net/ethernet/rocker/rocker_main.c
@@ -129,7 +129,7 @@ static int rocker_reg_test(const struct rocker *rocker)
 	u64 test_reg;
 	u64 rnd;
 
-	rnd = prandom_u32();
+	rnd = get_random_u32();
 	rnd >>= 1;
 	rocker_write32(rocker, TEST_REG, rnd);
 	test_reg = rocker_read32(rocker, TEST_REG);
@@ -139,9 +139,9 @@ static int rocker_reg_test(const struct rocker *rocker)
 		return -EIO;
 	}
 
-	rnd = prandom_u32();
+	rnd = get_random_u32();
 	rnd <<= 31;
-	rnd |= prandom_u32();
+	rnd |= get_random_u32();
 	rocker_write64(rocker, TEST_REG64, rnd);
 	test_reg = rocker_read64(rocker, TEST_REG64);
 	if (test_reg != rnd * 2) {
@@ -224,7 +224,7 @@ static int rocker_dma_test_offset(const struct rocker *rocker,
 	if (err)
 		goto unmap;
 
-	prandom_bytes(buf, ROCKER_TEST_DMA_BUF_SIZE);
+	get_random_bytes(buf, ROCKER_TEST_DMA_BUF_SIZE);
 	for (i = 0; i < ROCKER_TEST_DMA_BUF_SIZE; i++)
 		expect[i] = ~buf[i];
 	err = rocker_dma_test_one(rocker, wait, ROCKER_TEST_DMA_CTRL_INVERT,
diff --git a/drivers/net/hamradio/baycom_epp.c b/drivers/net/hamradio/baycom_epp.c
index 3e69079ed694..791b4a53d69f 100644
--- a/drivers/net/hamradio/baycom_epp.c
+++ b/drivers/net/hamradio/baycom_epp.c
@@ -438,7 +438,7 @@ static int transmit(struct baycom_state *bc, int cnt, unsigned char stat)
 			if ((--bc->hdlctx.slotcnt) > 0)
 				return 0;
 			bc->hdlctx.slotcnt = bc->ch_params.slottime;
-			if ((prandom_u32() % 256) > bc->ch_params.ppersist)
+			if (get_random_u8() > bc->ch_params.ppersist)
 				return 0;
 		}
 	}
diff --git a/drivers/net/hamradio/hdlcdrv.c b/drivers/net/hamradio/hdlcdrv.c
index a6184d6c7b15..2263029d1a20 100644
--- a/drivers/net/hamradio/hdlcdrv.c
+++ b/drivers/net/hamradio/hdlcdrv.c
@@ -377,7 +377,7 @@ void hdlcdrv_arbitrate(struct net_device *dev, struct hdlcdrv_state *s)
 	if ((--s->hdlctx.slotcnt) > 0)
 		return;
 	s->hdlctx.slotcnt = s->ch_params.slottime;
-	if ((prandom_u32() % 256) > s->ch_params.ppersist)
+	if (get_random_u8() > s->ch_params.ppersist)
 		return;
 	start_tx(dev, s);
 }
diff --git a/drivers/net/hamradio/yam.c b/drivers/net/hamradio/yam.c
index 980f2be32f05..2ed2f836f09a 100644
--- a/drivers/net/hamradio/yam.c
+++ b/drivers/net/hamradio/yam.c
@@ -626,7 +626,7 @@ static void yam_arbitrate(struct net_device *dev)
 	yp->slotcnt = yp->slot / 10;
 
 	/* is random > persist ? */
-	if ((prandom_u32() % 256) > yp->pers)
+	if (get_random_u8() > yp->pers)
 		return;
 
 	yam_start_tx(dev, yp);
diff --git a/drivers/net/phy/at803x.c b/drivers/net/phy/at803x.c
index 9e9adde335c8..349b7b1dbbf2 100644
--- a/drivers/net/phy/at803x.c
+++ b/drivers/net/phy/at803x.c
@@ -1758,7 +1758,7 @@ static int qca808x_phy_fast_retrain_config(struct phy_device *phydev)
 
 static int qca808x_phy_ms_random_seed_set(struct phy_device *phydev)
 {
-	u16 seed_value = (prandom_u32() % QCA808X_MASTER_SLAVE_SEED_RANGE);
+	u16 seed_value = prandom_u32_max(QCA808X_MASTER_SLAVE_SEED_RANGE);
 
 	return at803x_debug_reg_mask(phydev, QCA808X_PHY_DEBUG_LOCAL_SEED,
 			QCA808X_MASTER_SLAVE_SEED_CFG,
diff --git a/drivers/net/wireguard/selftest/allowedips.c b/drivers/net/wireguard/selftest/allowedips.c
index 41db10f9be49..19eac00b2381 100644
--- a/drivers/net/wireguard/selftest/allowedips.c
+++ b/drivers/net/wireguard/selftest/allowedips.c
@@ -284,7 +284,7 @@ static __init bool randomized_test(void)
 	mutex_lock(&mutex);
 
 	for (i = 0; i < NUM_RAND_ROUTES; ++i) {
-		prandom_bytes(ip, 4);
+		get_random_bytes(ip, 4);
 		cidr = prandom_u32_max(32) + 1;
 		peer = peers[prandom_u32_max(NUM_PEERS)];
 		if (wg_allowedips_insert_v4(&t, (struct in_addr *)ip, cidr,
@@ -299,7 +299,7 @@ static __init bool randomized_test(void)
 		}
 		for (j = 0; j < NUM_MUTATED_ROUTES; ++j) {
 			memcpy(mutated, ip, 4);
-			prandom_bytes(mutate_mask, 4);
+			get_random_bytes(mutate_mask, 4);
 			mutate_amount = prandom_u32_max(32);
 			for (k = 0; k < mutate_amount / 8; ++k)
 				mutate_mask[k] = 0xff;
@@ -310,7 +310,7 @@ static __init bool randomized_test(void)
 			for (k = 0; k < 4; ++k)
 				mutated[k] = (mutated[k] & mutate_mask[k]) |
 					     (~mutate_mask[k] &
-					      prandom_u32_max(256));
+					      get_random_u8());
 			cidr = prandom_u32_max(32) + 1;
 			peer = peers[prandom_u32_max(NUM_PEERS)];
 			if (wg_allowedips_insert_v4(&t,
@@ -328,7 +328,7 @@ static __init bool randomized_test(void)
 	}
 
 	for (i = 0; i < NUM_RAND_ROUTES; ++i) {
-		prandom_bytes(ip, 16);
+		get_random_bytes(ip, 16);
 		cidr = prandom_u32_max(128) + 1;
 		peer = peers[prandom_u32_max(NUM_PEERS)];
 		if (wg_allowedips_insert_v6(&t, (struct in6_addr *)ip, cidr,
@@ -343,7 +343,7 @@ static __init bool randomized_test(void)
 		}
 		for (j = 0; j < NUM_MUTATED_ROUTES; ++j) {
 			memcpy(mutated, ip, 16);
-			prandom_bytes(mutate_mask, 16);
+			get_random_bytes(mutate_mask, 16);
 			mutate_amount = prandom_u32_max(128);
 			for (k = 0; k < mutate_amount / 8; ++k)
 				mutate_mask[k] = 0xff;
@@ -354,7 +354,7 @@ static __init bool randomized_test(void)
 			for (k = 0; k < 4; ++k)
 				mutated[k] = (mutated[k] & mutate_mask[k]) |
 					     (~mutate_mask[k] &
-					      prandom_u32_max(256));
+					      get_random_u8());
 			cidr = prandom_u32_max(128) + 1;
 			peer = peers[prandom_u32_max(NUM_PEERS)];
 			if (wg_allowedips_insert_v6(&t,
@@ -381,13 +381,13 @@ static __init bool randomized_test(void)
 
 	for (j = 0;; ++j) {
 		for (i = 0; i < NUM_QUERIES; ++i) {
-			prandom_bytes(ip, 4);
+			get_random_bytes(ip, 4);
 			if (lookup(t.root4, 32, ip) != horrible_allowedips_lookup_v4(&h, (struct in_addr *)ip)) {
 				horrible_allowedips_lookup_v4(&h, (struct in_addr *)ip);
 				pr_err("allowedips random v4 self-test: FAIL\n");
 				goto free;
 			}
-			prandom_bytes(ip, 16);
+			get_random_bytes(ip, 16);
 			if (lookup(t.root6, 128, ip) != horrible_allowedips_lookup_v6(&h, (struct in6_addr *)ip)) {
 				pr_err("allowedips random v6 self-test: FAIL\n");
 				goto free;
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
index 479041f070f9..10d9d9c63b28 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
@@ -1128,7 +1128,7 @@ static void brcmf_p2p_afx_handler(struct work_struct *work)
 	if (afx_hdl->is_listen && afx_hdl->my_listen_chan)
 		/* 100ms ~ 300ms */
 		err = brcmf_p2p_discover_listen(p2p, afx_hdl->my_listen_chan,
-						100 * (1 + prandom_u32() % 3));
+						100 * (1 + prandom_u32_max(3)));
 	else
 		err = brcmf_p2p_act_frm_search(p2p, afx_hdl->peer_listen_chan);
 
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pno.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pno.c
index d0a7465be586..170c61c8136c 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pno.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pno.c
@@ -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;
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c b/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c
index ed586e6d7d64..de0c545d50fd 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c
@@ -1099,7 +1099,7 @@ static void iwl_mvm_mac_ctxt_cmd_fill_ap(struct iwl_mvm *mvm,
 			iwl_mvm_mac_ap_iterator, &data);
 
 		if (data.beacon_device_ts) {
-			u32 rand = (prandom_u32() % (64 - 36)) + 36;
+			u32 rand = prandom_u32_max(64 - 36) + 36;
 			mvmvif->ap_beacon_time = data.beacon_device_ts +
 				ieee80211_tu_to_usec(data.beacon_int * rand /
 						     100);
diff --git a/drivers/net/wireless/marvell/mwifiex/cfg80211.c b/drivers/net/wireless/marvell/mwifiex/cfg80211.c
index 535995e8279f..bcd564dc3554 100644
--- a/drivers/net/wireless/marvell/mwifiex/cfg80211.c
+++ b/drivers/net/wireless/marvell/mwifiex/cfg80211.c
@@ -239,7 +239,7 @@ mwifiex_cfg80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev,
 	tx_info->pkt_len = pkt_len;
 
 	mwifiex_form_mgmt_frame(skb, buf, len);
-	*cookie = prandom_u32() | 1;
+	*cookie = get_random_u32() | 1;
 
 	if (ieee80211_is_action(mgmt->frame_control))
 		skb = mwifiex_clone_skb_for_tx_status(priv,
@@ -303,7 +303,7 @@ mwifiex_cfg80211_remain_on_channel(struct wiphy *wiphy,
 					 duration);
 
 	if (!ret) {
-		*cookie = prandom_u32() | 1;
+		*cookie = get_random_u32() | 1;
 		priv->roc_cfg.cookie = *cookie;
 		priv->roc_cfg.chan = *chan;
 
diff --git a/drivers/net/wireless/microchip/wilc1000/cfg80211.c b/drivers/net/wireless/microchip/wilc1000/cfg80211.c
index b89047965e78..9bbfff803357 100644
--- a/drivers/net/wireless/microchip/wilc1000/cfg80211.c
+++ b/drivers/net/wireless/microchip/wilc1000/cfg80211.c
@@ -1161,7 +1161,7 @@ static int mgmt_tx(struct wiphy *wiphy,
 	const u8 *vendor_ie;
 	int ret = 0;
 
-	*cookie = prandom_u32();
+	*cookie = get_random_u32();
 	priv->tx_cookie = *cookie;
 	mgmt = (const struct ieee80211_mgmt *)buf;
 
diff --git a/drivers/net/wireless/quantenna/qtnfmac/cfg80211.c b/drivers/net/wireless/quantenna/qtnfmac/cfg80211.c
index bfdf03bfa6c5..73e6f9408b51 100644
--- a/drivers/net/wireless/quantenna/qtnfmac/cfg80211.c
+++ b/drivers/net/wireless/quantenna/qtnfmac/cfg80211.c
@@ -449,7 +449,7 @@ qtnf_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev,
 {
 	struct qtnf_vif *vif = qtnf_netdev_get_priv(wdev->netdev);
 	const struct ieee80211_mgmt *mgmt_frame = (void *)params->buf;
-	u32 short_cookie = prandom_u32();
+	u32 short_cookie = get_random_u32();
 	u16 flags = 0;
 	u16 freq;
 
diff --git a/drivers/net/wireless/st/cw1200/wsm.c b/drivers/net/wireless/st/cw1200/wsm.c
index 5a3e7a626702..4a9e4b5d3547 100644
--- a/drivers/net/wireless/st/cw1200/wsm.c
+++ b/drivers/net/wireless/st/cw1200/wsm.c
@@ -1594,7 +1594,7 @@ static int cw1200_get_prio_queue(struct cw1200_common *priv,
 		edca = &priv->edca.params[i];
 		score = ((edca->aifns + edca->cwmin) << 16) +
 			((edca->cwmax - edca->cwmin) *
-			 (get_random_int() & 0xFFFF));
+			 get_random_u16());
 		if (score < best && (winner < 0 || i != 3)) {
 			best = score;
 			winner = i;
diff --git a/drivers/net/wireless/ti/wlcore/main.c b/drivers/net/wireless/ti/wlcore/main.c
index 3e3922d4c788..28c0f06e311f 100644
--- a/drivers/net/wireless/ti/wlcore/main.c
+++ b/drivers/net/wireless/ti/wlcore/main.c
@@ -6100,7 +6100,7 @@ static int wl1271_register_hw(struct wl1271 *wl)
 			wl1271_warning("Fuse mac address is zero. using random mac");
 			/* Use TI oui and a random nic */
 			oui_addr = WLCORE_TI_OUI_ADDRESS;
-			nic_addr = get_random_int();
+			nic_addr = get_random_u32();
 		} else {
 			oui_addr = wl->fuse_oui_addr;
 			/* fuse has the BD_ADDR, the WLAN addresses are the next two */