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authorJason A. Donenfeld <Jason@zx2c4.com>2022-10-05 17:23:53 +0200
committerJason A. Donenfeld <Jason@zx2c4.com>2022-10-11 17:42:58 -0600
commit7e3cf0843fe505491baa05e355e83e6997e089dd (patch)
tree4ae7c859cd5b468d9f0209f23e17bd73f9c8bc43 /drivers/net
parent8b3ccbc1f1f91847160951aa15dd27c22dddcb49 (diff)
downloadlinux-7e3cf0843fe505491baa05e355e83e6997e089dd.tar.bz2
treewide: use get_random_{u8,u16}() when possible, part 1
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@linuxfoundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Yury Norov <yury.norov@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> # for sch_cake Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Diffstat (limited to 'drivers/net')
-rw-r--r--drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_cm.c2
-rw-r--r--drivers/net/hamradio/baycom_epp.c2
-rw-r--r--drivers/net/hamradio/hdlcdrv.c2
-rw-r--r--drivers/net/hamradio/yam.c2
-rw-r--r--drivers/net/wireguard/selftest/allowedips.c4
-rw-r--r--drivers/net/wireless/st/cw1200/wsm.c2
6 files changed, 7 insertions, 7 deletions
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;