OpenCloudOS-Kernel/net/tipc
Jason A. Donenfeld 81895a65ec treewide: use prandom_u32_max() when possible, part 1
Rather than incurring a division or requesting too many random bytes for
the given range, use the prandom_u32_max() function, which only takes
the minimum required bytes from the RNG and avoids divisions. This was
done mechanically with this coccinelle script:

@basic@
expression E;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
typedef u64;
@@
(
- ((T)get_random_u32() % (E))
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ((E) - 1))
+ prandom_u32_max(E * XXX_MAKE_SURE_E_IS_POW2)
|
- ((u64)(E) * get_random_u32() >> 32)
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ~PAGE_MASK)
+ prandom_u32_max(PAGE_SIZE)
)

@multi_line@
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
identifier RAND;
expression E;
@@

-       RAND = get_random_u32();
        ... when != RAND
-       RAND %= (E);
+       RAND = prandom_u32_max(E);

// 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))

// Add one to the literal.
@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 == 2**32 - 1 or value == 2**31 - 1 or value == 2**24 - 1 or value == 2**16 - 1 or value == 2**8 - 1:
        print("Skipping 0x%x for cleanup elsewhere" % (value))
        cocci.include_match(False)
elif value & (value + 1) != 0:
        print("Skipping 0x%x because it's not a power of two minus one" % (value))
        cocci.include_match(False)
elif literal.startswith('0x'):
        coccinelle.RESULT = cocci.make_expr("0x%x" % (value + 1))
else:
        coccinelle.RESULT = cocci.make_expr("%d" % (value + 1))

// Replace the literal mask with the calculated result.
@plus_one@
expression literal_mask.LITERAL;
position literal_mask.p;
expression add_one.RESULT;
identifier FUNC;
@@

-       (FUNC()@p & (LITERAL))
+       prandom_u32_max(RESULT)

@collapse_ret@
type T;
identifier VAR;
expression E;
@@

 {
-       T VAR;
-       VAR = (E);
-       return VAR;
+       return E;
 }

@drop_var@
type T;
identifier VAR;
@@

 {
-       T VAR;
        ... when != VAR
 }

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: KP Singh <kpsingh@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz> # for ext4 and sbitmap
Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> # for drbd
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-10-11 17:42:55 -06:00
..
Kconfig tipc: not enable tipc when ipv6 works as a module 2020-08-16 21:04:55 -07:00
Makefile tipc: remove meaningless assignment in Makefile 2020-01-08 12:38:54 -08:00
addr.c tipc: introduce new unified address type for internal use 2021-03-17 11:51:04 -07:00
addr.h tipc: introduce new unified address type for internal use 2021-03-17 11:51:04 -07:00
bcast.c net: tipc: fix FB_MTU eat two pages 2021-06-28 13:31:57 -07:00
bcast.h tipc: update a binding service via broadcast 2020-06-17 08:53:34 -07:00
bearer.c net: rename reference+tracking helpers 2022-06-09 21:52:55 -07:00
bearer.h tipc: constify dev_addr passing 2021-10-13 09:40:46 -07:00
core.c tipc: fix use-after-free Read in tipc_named_reinit 2022-06-17 11:39:10 +01:00
core.h tipc: simplify the finalize work queue 2021-05-18 13:22:09 -07:00
crypto.c tipc: fix a bit overflow in tipc_crypto_key_rcv() 2022-02-13 12:12:25 +00:00
crypto.h net/tipc: fix tipc header files for kernel-doc 2020-12-01 15:37:41 -08:00
diag.c
discover.c tipc: simplify the finalize work queue 2021-05-18 13:22:09 -07:00
discover.h
eth_media.c tipc: constify dev_addr passing 2021-10-13 09:40:46 -07:00
group.c tipc: update address terminology in code 2020-11-27 17:34:01 -08:00
group.h tipc: update address terminology in code 2020-11-27 17:34:01 -08:00
ib_media.c tipc: constify dev_addr passing 2021-10-13 09:40:46 -07:00
link.c tipc: fix incorrect order of state message data sanity check 2022-03-08 22:18:42 -08:00
link.h tipc: simplify the finalize work queue 2021-05-18 13:22:09 -07:00
monitor.c tipc: fix shift wrapping bug in map_get() 2022-09-02 12:26:29 +01:00
monitor.h tipc: update mon's self addr when node addr generated 2019-11-12 19:45:45 -08:00
msg.c net: tipc: replace align() with ALIGN in msg.c 2021-06-28 13:31:57 -07:00
msg.h net: tipc: remove unused static inlines 2022-01-27 13:53:27 +00:00
name_distr.c net/tipc: Remove unused struct distr_queue_item 2022-09-29 18:48:32 -07:00
name_distr.h net/tipc: fix tipc header files for kernel-doc 2020-12-01 15:37:41 -08:00
name_table.c tipc: cleanup unused function 2022-06-17 11:43:57 +01:00
name_table.h tipc: cleanup unused function 2022-06-17 11:43:57 +01:00
net.c tipc: simplify the finalize work queue 2021-05-18 13:22:09 -07:00
net.h tipc: fix a deadlock when flushing scheduled work 2020-09-07 12:08:53 -07:00
netlink.c genetlink: start to validate reserved header bytes 2022-08-29 12:47:15 +01:00
netlink.h net: tipc: allocate attrs locally instead of using genl_family_attrbuf in compat_dumpit() 2019-10-06 15:44:47 +02:00
netlink_compat.c genetlink: start to validate reserved header bytes 2022-08-29 12:47:15 +01:00
node.c tipc: move bc link creation back to tipc_node_create 2022-06-27 11:51:56 +01:00
node.h tipc: add automatic session key exchange 2020-09-18 13:58:37 -07:00
socket.c treewide: use prandom_u32_max() when possible, part 1 2022-10-11 17:42:55 -06:00
socket.h tipc: add stricter control of reserved service types 2020-10-30 08:19:18 -07:00
subscr.c tipc:subscr.c: fix a spelling mistake 2021-06-10 13:48:43 -07:00
subscr.h tipc: fix htmldoc and smatch warnings 2021-03-29 16:28:50 -07:00
sysctl.c tipc: add automatic session key exchange 2020-09-18 13:58:37 -07:00
topsrv.c tipc: update address terminology in code 2020-11-27 17:34:01 -08:00
topsrv.h
trace.c net/tipc: fix various kernel-doc warnings 2020-12-01 15:37:46 -08:00
trace.h tipc: add support for broadcast rcv stats dumping 2020-05-26 15:16:52 -07:00
udp_media.c tipc: wait and exit until all work queues are done 2021-05-17 14:07:48 -07:00
udp_media.h