linux/net/sched
Jason A. Donenfeld 7e3cf0843f 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>
2022-10-11 17:42:58 -06:00
..
act_api.c net: sched: act_api: implement generic walker and search for tc action 2022-09-09 08:24:41 +01:00
act_bpf.c net: sched: act_bpf: simplify code logic in tcf_bpf_init() 2022-09-28 09:38:56 +01:00
act_connmark.c net: sched: act_connmark: get rid of tcf_connmark_walker and tcf_connmark_search 2022-09-09 08:24:41 +01:00
act_csum.c net: sched: act_csum: get rid of tcf_csum_walker and tcf_csum_search 2022-09-09 08:24:41 +01:00
act_ct.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-09-29 14:30:51 -07:00
act_ctinfo.c net: sched: act_ctinfo: get rid of tcf_ctinfo_walker and tcf_ctinfo_search 2022-09-09 08:24:41 +01:00
act_gact.c treewide: use prandom_u32_max() when possible, part 1 2022-10-11 17:42:55 -06:00
act_gate.c net: sched: act_gate: get rid of tcf_gate_walker and tcf_gate_search 2022-09-09 08:24:42 +01:00
act_ife.c net: sched: act_ife: get rid of tcf_ife_walker and tcf_ife_search 2022-09-09 08:24:42 +01:00
act_ipt.c net: sched: act_ipt: get rid of tcf_ipt_walker/tcf_xt_walker and tcf_ipt_search/tcf_xt_search 2022-09-09 08:24:42 +01:00
act_meta_mark.c
act_meta_skbprio.c
act_meta_skbtcindex.c
act_mirred.c net: sched: remove unused tcf_result extension 2022-09-21 18:32:33 -07:00
act_mpls.c net: sched: act_mpls: get rid of tcf_mpls_walker and tcf_mpls_search 2022-09-09 08:24:42 +01:00
act_nat.c net: sched: act_nat: get rid of tcf_nat_walker and tcf_nat_search 2022-09-09 08:24:42 +01:00
act_pedit.c net: sched: act_pedit: get rid of tcf_pedit_walker and tcf_pedit_search 2022-09-09 08:24:42 +01:00
act_police.c net: sched: act_police: get rid of tcf_police_walker and tcf_police_search 2022-09-09 08:24:42 +01:00
act_sample.c treewide: use prandom_u32_max() when possible, part 1 2022-10-11 17:42:55 -06:00
act_simple.c net: sched: act_simple: get rid of tcf_simp_walker and tcf_simp_search 2022-09-09 08:24:42 +01:00
act_skbedit.c net: sched: act_skbedit: get rid of tcf_skbedit_walker and tcf_skbedit_search 2022-09-09 08:24:42 +01:00
act_skbmod.c net: sched: act_skbmod: get rid of tcf_skbmod_walker and tcf_skbmod_search 2022-09-09 08:24:42 +01:00
act_tunnel_key.c net: sched: act_tunnel_key: get rid of tunnel_key_walker and tunnel_key_search 2022-09-09 08:24:42 +01:00
act_vlan.c net: sched: act_vlan: get rid of tcf_vlan_walker and tcf_vlan_search 2022-09-09 08:24:43 +01:00
cls_api.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-09-22 13:02:10 -07:00
cls_basic.c net: sched: use tc_cls_bind_class() in filter 2022-10-02 16:07:17 +01:00
cls_bpf.c net: sched: use tc_cls_bind_class() in filter 2022-10-02 16:07:17 +01:00
cls_cgroup.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
cls_flow.c net/sched: use tc_cls_stats_dump() in filter 2022-09-20 15:54:13 -07:00
cls_flower.c net: sched: use tc_cls_bind_class() in filter 2022-10-02 16:07:17 +01:00
cls_fw.c net: sched: use tc_cls_bind_class() in filter 2022-10-02 16:07:17 +01:00
cls_matchall.c net: sched: use tc_cls_bind_class() in filter 2022-10-02 16:07:17 +01:00
cls_route.c net: sched: use tc_cls_bind_class() in filter 2022-10-02 16:07:17 +01:00
cls_rsvp6.c
cls_rsvp.c
cls_rsvp.h net: sched: use tc_cls_bind_class() in filter 2022-10-02 16:07:17 +01:00
cls_tcindex.c net: sched: use tc_cls_bind_class() in filter 2022-10-02 16:07:17 +01:00
cls_u32.c net: sched: use tc_cls_bind_class() in filter 2022-10-02 16:07:17 +01:00
em_canid.c
em_cmp.c net: sched: fix misspellings using misspell-fixer tool 2020-11-10 17:00:28 -08:00
em_ipset.c
em_ipt.c
em_meta.c net_sched: em_meta: add READ_ONCE() in var_sk_bound_if() 2022-05-16 10:31:06 +01:00
em_nbyte.c net: sched: Return the correct errno code 2021-02-06 11:15:28 -08:00
em_text.c
em_u32.c
ematch.c net: sched: Fix spelling mistakes 2021-05-31 22:44:56 -07:00
Kconfig net: sched: incorrect Kconfig dependencies on Netfilter modules 2020-12-09 15:49:29 -08:00
Makefile net/sched: sch_frag: add generic packet fragment support. 2020-11-27 14:36:02 -08:00
sch_api.c net: sched: ensure n arg not empty before call bind_class 2022-10-02 16:07:17 +01:00
sch_atm.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_blackhole.c Revert "net: sched: Pass root lock to Qdisc_ops.enqueue" 2020-07-16 16:48:34 -07:00
sch_cake.c treewide: use get_random_{u8,u16}() when possible, part 1 2022-10-11 17:42:58 -06:00
sch_cbq.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_cbs.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_choke.c net: sched: choke: remove unused variables in struct choke_sched_data 2022-08-31 19:39:53 -07:00
sch_codel.c net: sched: remove redundant NULL check in change hook function 2022-09-01 08:06:45 +02:00
sch_drr.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_dsmark.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_etf.c net: sched: etf: remove true check in etf_enable_offload() 2022-09-01 20:08:32 -07:00
sch_ets.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_fifo.c net_sched: fix NULL deref in fifo_set_limit() 2021-10-01 14:59:10 -07:00
sch_fq_codel.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_fq_pie.c net: sched: remove redundant NULL check in change hook function 2022-09-01 08:06:45 +02:00
sch_fq.c net: sched: remove redundant NULL check in change hook function 2022-09-01 08:06:45 +02:00
sch_frag.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-12-31 14:35:40 +00:00
sch_generic.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-09-01 12:58:02 -07:00
sch_gred.c net: sched: gred: remove NULL check before free table->tab in gred_destroy() 2022-09-01 13:32:26 +02:00
sch_hfsc.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_hhf.c net: sched: remove redundant NULL check in change hook function 2022-09-01 08:06:45 +02:00
sch_htb.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_ingress.c
sch_mq.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_mqprio.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_multiq.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_netem.c treewide: use prandom_u32_max() when possible, part 1 2022-10-11 17:42:55 -06:00
sch_pie.c net: sched: remove redundant NULL check in change hook function 2022-09-01 08:06:45 +02:00
sch_plug.c net: sched: remove redundant NULL check in change hook function 2022-09-01 08:06:45 +02:00
sch_prio.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_qfq.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_red.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_sfb.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_sfq.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_skbprio.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_taprio.c net/sched: taprio: allow user input of per-tc max SDU 2022-09-29 18:52:05 -07:00
sch_tbf.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_teql.c net: sched: delete duplicate cleanup of backlog and qlen 2022-08-25 15:10:17 +02:00