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
mechanically with this coccinelle script:
@@
expression E;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
typedef u16;
typedef __be16;
typedef __le16;
typedef u8;
@@
(
- (get_random_u32() & 0xffff)
+ get_random_u16()
|
- (get_random_u32() & 0xff)
+ get_random_u8()
|
- (get_random_u32() % 65536)
+ get_random_u16()
|
- (get_random_u32() % 256)
+ get_random_u8()
|
- (get_random_u32() >> 16)
+ get_random_u16()
|
- (get_random_u32() >> 24)
+ get_random_u8()
|
- (u16)get_random_u32()
+ get_random_u16()
|
- (u8)get_random_u32()
+ get_random_u8()
|
- (__be16)get_random_u32()
+ (__be16)get_random_u16()
|
- (__le16)get_random_u32()
+ (__le16)get_random_u16()
|
- prandom_u32_max(65536)
+ get_random_u16()
|
- prandom_u32_max(256)
+ get_random_u8()
|
- E->inet_id = get_random_u32()
+ E->inet_id = get_random_u16()
)
@@
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
typedef u16;
identifier v;
@@
- u16 v = get_random_u32();
+ u16 v = get_random_u16();
@@
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
typedef u8;
identifier v;
@@
- u8 v = get_random_u32();
+ u8 v = get_random_u8();
@@
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
typedef u16;
u16 v;
@@
- v = get_random_u32();
+ v = get_random_u16();
@@
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
typedef u8;
u8 v;
@@
- v = get_random_u32();
+ v = get_random_u8();
// Find a potential literal
@literal_mask@
expression LITERAL;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
position p;
@@
((T)get_random_u32()@p & (LITERAL))
// Examine limits
@script:python add_one@
literal << literal_mask.LITERAL;
RESULT;
@@
value = None
if literal.startswith('0x'):
value = int(literal, 16)
elif literal[0] in '123456789':
value = int(literal, 10)
if value is None:
print("I don't know how to handle %s" % (literal))
cocci.include_match(False)
elif value < 256:
coccinelle.RESULT = cocci.make_ident("get_random_u8")
elif value < 65536:
coccinelle.RESULT = cocci.make_ident("get_random_u16")
else:
print("Skipping large mask of %s" % (literal))
cocci.include_match(False)
// Replace the literal mask with the calculated result.
@plus_one@
expression literal_mask.LITERAL;
position literal_mask.p;
identifier add_one.RESULT;
identifier FUNC;
@@
- (FUNC()@p & (LITERAL))
+ (RESULT() & LITERAL)
Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Reviewed-by: Yury Norov <yury.norov@xxxxxxxxx>
Acked-by: Toke Høiland-Jørgensen <toke@xxxxxxx> # for sch_cake
Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
---
arch/arm/kernel/signal.c | 2 +-
arch/arm64/kernel/syscall.c | 2 +-
crypto/testmgr.c | 8 ++++----
drivers/media/common/v4l2-tpg/v4l2-tpg-core.c | 2 +-
drivers/media/test-drivers/vivid/vivid-radio-rx.c | 4 ++--
.../net/ethernet/chelsio/inline_crypto/chtls/chtls_cm.c | 2 +-
drivers/net/hamradio/baycom_epp.c | 2 +-
drivers/net/hamradio/hdlcdrv.c | 2 +-
drivers/net/hamradio/yam.c | 2 +-
drivers/net/wireguard/selftest/allowedips.c | 4 ++--
drivers/net/wireless/st/cw1200/wsm.c | 2 +-
drivers/scsi/lpfc/lpfc_hbadisc.c | 6 +++---
lib/cmdline_kunit.c | 4 ++--
net/dccp/ipv4.c | 4 ++--
net/ipv4/datagram.c | 2 +-
net/ipv4/ip_output.c | 2 +-
net/ipv4/tcp_ipv4.c | 4 ++--
net/mac80211/scan.c | 2 +-
net/netfilter/nf_nat_core.c | 4 ++--
net/sched/sch_cake.c | 6 +++---
net/sctp/socket.c | 2 +-
21 files changed, 34 insertions(+), 34 deletions(-)
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index ea128e32e8ca..e07f359254c3 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -655,7 +655,7 @@ struct page *get_signal_page(void)
PAGE_SIZE / sizeof(u32));
/* Give the signal return code some randomness */
- offset = 0x200 + (get_random_int() & 0x7fc);
+ offset = 0x200 + (get_random_u16() & 0x7fc);
signal_return_offset = offset;
/* Copy signal return handlers into the page */
diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c
index 733451fe7e41..d72e8f23422d 100644
--- a/arch/arm64/kernel/syscall.c
+++ b/arch/arm64/kernel/syscall.c
@@ -67,7 +67,7 @@ static void invoke_syscall(struct pt_regs *regs, unsigned int scno,
*
* The resulting 5 bits of entropy is seen in SP[8:4].
*/
- choose_random_kstack_offset(get_random_int() & 0x1FF);
+ choose_random_kstack_offset(get_random_u16() & 0x1FF);
}
static inline bool has_syscall_work(unsigned long flags)
diff --git a/crypto/testmgr.c b/crypto/testmgr.c
index be45217acde4..981c637fa2ed 100644
--- a/crypto/testmgr.c
+++ b/crypto/testmgr.c
@@ -927,7 +927,7 @@ static void generate_random_bytes(u8 *buf, size_t count)
b = 0xff;
break;
default:
- b = (u8)prandom_u32();
+ b = get_random_u8();
break;
}
memset(buf, b, count);
@@ -935,8 +935,8 @@ static void generate_random_bytes(u8 *buf, size_t count)
break;
case 2:
/* Ascending or descending bytes, plus optional mutations */
- increment = (u8)prandom_u32();
- b = (u8)prandom_u32();
+ increment = get_random_u8();
+ b = get_random_u8();
for (i = 0; i < count; i++, b += increment)
buf[i] = b;
mutate_buffer(buf, count);
@@ -944,7 +944,7 @@ static void generate_random_bytes(u8 *buf, size_t count)
default:
/* Fully random bytes */
for (i = 0; i < count; i++)
- buf[i] = (u8)prandom_u32();
+ buf[i] = get_random_u8();
}
}
diff --git a/drivers/media/common/v4l2-tpg/v4l2-tpg-core.c b/drivers/media/common/v4l2-tpg/v4l2-tpg-core.c
index 9b7bcdce6e44..303d02b1d71c 100644
--- a/drivers/media/common/v4l2-tpg/v4l2-tpg-core.c
+++ b/drivers/media/common/v4l2-tpg/v4l2-tpg-core.c
@@ -870,7 +870,7 @@ static void precalculate_color(struct tpg_data *tpg, int k)
g = tpg_colors[col].g;
b = tpg_colors[col].b;
} else if (tpg->pattern == TPG_PAT_NOISE) {
- r = g = b = prandom_u32_max(256);
+ r = g = b = get_random_u8();
} else if (k == TPG_COLOR_RANDOM) {
r = g = b = tpg->qual_offset + prandom_u32_max(196);
} else if (k >= TPG_COLOR_RAMP) {
diff --git a/drivers/media/test-drivers/vivid/vivid-radio-rx.c b/drivers/media/test-drivers/vivid/vivid-radio-rx.c
index 232cab508f48..8bd09589fb15 100644
--- a/drivers/media/test-drivers/vivid/vivid-radio-rx.c
+++ b/drivers/media/test-drivers/vivid/vivid-radio-rx.c
@@ -104,8 +104,8 @@ ssize_t vivid_radio_rx_read(struct file *file, char __user *buf,
break;
case 2:
rds.block |= V4L2_RDS_BLOCK_ERROR;
- rds.lsb = prandom_u32_max(256);
- rds.msb = prandom_u32_max(256);
+ rds.lsb = get_random_u8();
+ rds.msb = get_random_u8();
break;
case 3: /* Skip block altogether */
if (i)
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..eda129d0143e 100644
--- a/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_cm.c
+++ b/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_cm.c
@@ -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/hamradio/baycom_epp.c b/drivers/net/hamradio/baycom_epp.c
index 7df78a721b04..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_max(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 bef904325a0f..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_max(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 97a6cc5c7ae8..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_max(256) > yp->pers)
+ if (get_random_u8() > yp->pers)
return;
yam_start_tx(dev, yp);
diff --git a/drivers/net/wireguard/selftest/allowedips.c b/drivers/net/wireguard/selftest/allowedips.c
index 41db10f9be49..dd897c0740a2 100644
--- a/drivers/net/wireguard/selftest/allowedips.c
+++ b/drivers/net/wireguard/selftest/allowedips.c
@@ -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,
@@ -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,
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/scsi/lpfc/lpfc_hbadisc.c b/drivers/scsi/lpfc/lpfc_hbadisc.c
index c7f834ba8edb..d38ebd7281b9 100644
--- a/drivers/scsi/lpfc/lpfc_hbadisc.c
+++ b/drivers/scsi/lpfc/lpfc_hbadisc.c
@@ -2156,8 +2156,8 @@ lpfc_check_pending_fcoe_event(struct lpfc_hba *phba, uint8_t unreg_fcf)
* This function makes an running random selection decision on FCF record to
* use through a sequence of @fcf_cnt eligible FCF records with equal
* probability. To perform integer manunipulation of random numbers with
- * size unit32_t, the lower 16 bits of the 32-bit random number returned
- * from prandom_u32() are taken as the random random number generated.
+ * size unit32_t, a 16-bit random number returned from get_random_u16() is
+ * taken as the random random number generated.
*
* Returns true when outcome is for the newly read FCF record should be
* chosen; otherwise, return false when outcome is for keeping the previously
@@ -2169,7 +2169,7 @@ lpfc_sli4_new_fcf_random_select(struct lpfc_hba *phba, uint32_t fcf_cnt)
uint32_t rand_num;
/* Get 16-bit uniform random number */
- rand_num = 0xFFFF & prandom_u32();
+ rand_num = get_random_u16();
/* Decision with probability 1/fcf_cnt */
if ((fcf_cnt * rand_num) < 0xFFFF)
diff --git a/lib/cmdline_kunit.c b/lib/cmdline_kunit.c
index a72a2c16066e..d4572dbc9145 100644
--- a/lib/cmdline_kunit.c
+++ b/lib/cmdline_kunit.c
@@ -76,7 +76,7 @@ static void cmdline_test_lead_int(struct kunit *test)
int rc = cmdline_test_values[i];
int offset;
- sprintf(in, "%u%s", get_random_int() % 256, str);
+ sprintf(in, "%u%s", get_random_u8(), str);
/* Only first '-' after the number will advance the pointer */
offset = strlen(in) - strlen(str) + !!(rc == 2);
cmdline_do_one_test(test, in, rc, offset);
@@ -94,7 +94,7 @@ static void cmdline_test_tail_int(struct kunit *test)
int rc = strcmp(str, "") ? (strcmp(str, "-") ? 0 : 1) : 1;
int offset;
- sprintf(in, "%s%u", str, get_random_int() % 256);
+ sprintf(in, "%s%u", str, get_random_u8());
/*
* Only first and leading '-' not followed by integer
* will advance the pointer.
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index 6a6e121dc00c..713b7b8dad7e 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -144,7 +144,7 @@ int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
inet->inet_daddr,
inet->inet_sport,
inet->inet_dport);
- inet->inet_id = prandom_u32();
+ inet->inet_id = get_random_u16();
err = dccp_connect(sk);
rt = NULL;
@@ -443,7 +443,7 @@ struct sock *dccp_v4_request_recv_sock(const struct sock *sk,
RCU_INIT_POINTER(newinet->inet_opt, rcu_dereference(ireq->ireq_opt));
newinet->mc_index = inet_iif(skb);
newinet->mc_ttl = ip_hdr(skb)->ttl;
- newinet->inet_id = prandom_u32();
+ newinet->inet_id = get_random_u16();
if (dst == NULL && (dst = inet_csk_route_child_sock(sk, newsk, req)) == NULL)
goto put_and_exit;
diff --git a/net/ipv4/datagram.c b/net/ipv4/datagram.c
index 405a8c2aea64..0ee7fd259730 100644
--- a/net/ipv4/datagram.c
+++ b/net/ipv4/datagram.c
@@ -73,7 +73,7 @@ int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len
reuseport_has_conns(sk, true);
sk->sk_state = TCP_ESTABLISHED;
sk_set_txhash(sk);
- inet->inet_id = prandom_u32();
+ inet->inet_id = get_random_u16();
sk_dst_set(sk, &rt->dst);
err = 0;
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 1ae83ad629b2..922c87ef1ab5 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -172,7 +172,7 @@ int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk,
* Avoid using the hashed IP ident generator.
*/
if (sk->sk_protocol == IPPROTO_TCP)
- iph->id = (__force __be16)prandom_u32();
+ iph->id = (__force __be16)get_random_u16();
else
__ip_select_ident(net, iph, 1);
}
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 6376ad915765..7a250ef9d1b7 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -323,7 +323,7 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
inet->inet_daddr);
}
- inet->inet_id = prandom_u32();
+ inet->inet_id = get_random_u16();
if (tcp_fastopen_defer_connect(sk, &err))
return err;
@@ -1543,7 +1543,7 @@ struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
inet_csk(newsk)->icsk_ext_hdr_len = 0;
if (inet_opt)
inet_csk(newsk)->icsk_ext_hdr_len = inet_opt->opt.optlen;
- newinet->inet_id = prandom_u32();
+ newinet->inet_id = get_random_u16();
/* Set ToS of the new socket based upon the value of incoming SYN.
* ECT bits are set later in tcp_init_transfer().
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 0e8c4f48c36d..dc3cdee51e66 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -641,7 +641,7 @@ static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
struct ieee80211_hdr *hdr = (void *)skb->data;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
- u16 sn = get_random_u32();
+ u16 sn = get_random_u16();
info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
hdr->seq_ctrl =
diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c
index d8e6380f6337..18319a6e6806 100644
--- a/net/netfilter/nf_nat_core.c
+++ b/net/netfilter/nf_nat_core.c
@@ -468,7 +468,7 @@ static void nf_nat_l4proto_unique_tuple(struct nf_conntrack_tuple *tuple,
if (range->flags & NF_NAT_RANGE_PROTO_OFFSET)
off = (ntohs(*keyptr) - ntohs(range->base_proto.all));
else
- off = prandom_u32();
+ off = get_random_u16();
attempts = range_size;
if (attempts > max_attempts)
@@ -490,7 +490,7 @@ static void nf_nat_l4proto_unique_tuple(struct nf_conntrack_tuple *tuple,
if (attempts >= range_size || attempts < 16)
return;
attempts /= 2;
- off = prandom_u32();
+ off = get_random_u16();
goto another_round;
}
diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index 55c6879d2c7e..7193d25932ce 100644
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
@@ -2092,11 +2092,11 @@ static struct sk_buff *cake_dequeue(struct Qdisc *sch)
WARN_ON(host_load > CAKE_QUEUES);
- /* The shifted prandom_u32() is a way to apply dithering to
- * avoid accumulating roundoff errors
+ /* The get_random_u16() is a way to apply dithering to avoid
+ * accumulating roundoff errors
*/
flow->deficit += (b->flow_quantum * quantum_div[host_load] +
- (prandom_u32() >> 16)) >> 16;
+ get_random_u16()) >> 16;
list_move_tail(&flow->flowchain, &b->old_flows);
goto retry;
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 1e354ba44960..83628c347744 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -9448,7 +9448,7 @@ void sctp_copy_sock(struct sock *newsk, struct sock *sk,
newinet->inet_rcv_saddr = inet->inet_rcv_saddr;
newinet->inet_dport = htons(asoc->peer.port);
newinet->pmtudisc = inet->pmtudisc;
- newinet->inet_id = prandom_u32();
+ newinet->inet_id = get_random_u16();
newinet->uc_ttl = inet->uc_ttl;
newinet->mc_loop = 1;
--
2.37.3
