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Eric Dumazet 0a14842f5a net: filter: Just In Time compiler for x86-64 
In order to speedup packet filtering, here is an implementation of a
JIT compiler for x86_64

It is disabled by default, and must be enabled by the admin.

echo 1 >/proc/sys/net/core/bpf_jit_enable

It uses module_alloc() and module_free() to get memory in the 2GB text
kernel range since we call helpers functions from the generated code.

EAX : BPF A accumulator
EBX : BPF X accumulator
RDI : pointer to skb   (first argument given to JIT function)
RBP : frame pointer (even if CONFIG_FRAME_POINTER=n)
r9d : skb->len - skb->data_len (headlen)
r8  : skb->data

To get a trace of generated code, use :

echo 2 >/proc/sys/net/core/bpf_jit_enable

Example of generated code :

# tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24

flen=18 proglen=147 pass=3 image=ffffffffa00b5000
JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60
JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00
JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00
JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be
JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0
JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00
JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00
JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24
JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31
JIT code: ffffffffa00b5090: c0 c9 c3

BPF program is 144 bytes long, so native program is almost same size ;)

(000) ldh      [12]
(001) jeq      #0x800           jt 2    jf 8
(002) ld       [26]
(003) and      #0xffffff00
(004) jeq      #0xc0a81400      jt 16   jf 5
(005) ld       [30]
(006) and      #0xffffff00
(007) jeq      #0xc0a81400      jt 16   jf 17
(008) jeq      #0x806           jt 10   jf 9
(009) jeq      #0x8035          jt 10   jf 17
(010) ld       [28]
(011) and      #0xffffff00
(012) jeq      #0xc0a81400      jt 16   jf 13
(013) ld       [38]
(014) and      #0xffffff00
(015) jeq      #0xc0a81400      jt 16   jf 17
(016) ret      #65535
(017) ret      #0

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Cc: Hagen Paul Pfeifer <hagen@jauu.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
 		2011-04-27 23:05:08 -07:00
..
9p 9p: Kill set but unused variable in 9p_client_{read,write}() and p9_client_readdir() 2011-04-12 15:58:41 -07:00
802
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8021q bonding, ipv4, ipv6, vlan: Handle NETDEV_BONDING_FAILOVER like NETDEV_NOTIFY_PEERS 2011-04-17 23:36:03 -07:00
appletalk appletalk: Fix OOPS in atalk_release(). 2011-03-31 18:59:10 -07:00
atm atm: lec: Fix set-but-unused variables. 2011-04-17 00:48:36 -07:00
ax25 ax25: Fix set-but-unused variable. 2011-04-17 00:48:31 -07:00
batman-adv net: batman-adv: remove rx_csum ethtool_ops 2011-04-20 01:30:40 -07:00
bluetooth Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2011-04-26 12:16:46 -07:00
bridge Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2011-04-26 12:16:46 -07:00
caif caif: Fix set-but-unused variables. 2011-04-17 16:57:55 -07:00
can Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2011-04-26 12:16:46 -07:00
ceph Merge branch 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6 2011-04-07 11:14:49 -07:00
core net: filter: Just In Time compiler for x86-64 2011-04-27 23:05:08 -07:00
dcb net: dcbnl: Update copyright dates 2011-03-14 17:02:42 -07:00
dccp ipv4: Sanitize and simplify ip_route_{connect,newports}() 2011-04-27 13:59:04 -07:00
decnet decnet: Don't leak entries when rebuilding zone. 2011-04-17 20:47:07 -07:00
dns_resolver DNS: Fix a NULL pointer deref when trying to read an error key [CVE-2011-1076] 2011-03-04 09:56:19 +11:00
dsa net: dsa: remove ethtool_ops->set_sg 2011-04-20 01:30:39 -07:00
econet econet: Fix set-but-unused variable. 2011-04-17 00:15:22 -07:00
ethernet eth: fix new kernel-doc warning 2011-01-12 19:00:40 -08:00
ieee802154 ieee802154: Remove hacked CFLAGS in net/ieee802154/Makefile 2011-04-12 15:33:23 -07:00
ipv4 ipv4: Remove erroneous check in igmpv3_newpack() and igmp_send_report(). 2011-04-27 13:59:05 -07:00
ipv6 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2011-04-26 12:16:46 -07:00
ipx ipx: fix ipx_release() 2011-03-21 18:16:39 -07:00
irda Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2011-04-19 00:21:33 -07:00
iucv Fix common misspellings 2011-03-31 11:26:23 -03:00
key inet: constify ip headers and in6_addr 2011-04-22 11:04:14 -07:00
l2tp ipv4: Sanitize and simplify ip_route_{connect,newports}() 2011-04-27 13:59:04 -07:00
lapb
…
llc llc: Fix length check in llc_fixup_skb(). 2011-04-11 18:59:05 -07:00
mac80211 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2011-04-26 12:16:46 -07:00
netfilter Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2011-04-26 12:16:46 -07:00
netlabel netlabel: Fix set-but-unused variables. 2011-04-17 17:01:49 -07:00
netlink Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2011-03-03 21:27:42 -08:00
netrom NET: AX.25, NETROM, ROSE: Remove SOCK_DEBUG calls 2011-04-14 00:20:07 -07:00
packet net: filter: Just In Time compiler for x86-64 2011-04-27 23:05:08 -07:00
phonet Phonet: convert bound sockets hash list to RCU 2011-04-14 21:32:53 -07:00
rds Fix common misspellings 2011-03-31 11:26:23 -03:00
rfkill rfkill: Regulator consumer driver for rfkill 2011-04-19 15:38:02 -04:00
rose NET: AX.25, NETROM, ROSE: Remove SOCK_DEBUG calls 2011-04-14 00:20:07 -07:00
rxrpc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2011-03-16 16:29:25 -07:00
sched inet: constify ip headers and in6_addr 2011-04-22 11:04:14 -07:00
sctp sctp: clean up route lookup calls 2011-04-27 13:14:06 -07:00
sunrpc Merge branch 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6 2011-04-08 11:47:35 -07:00
tipc Fix common misspellings 2011-03-31 11:26:23 -03:00
unix Fix common misspellings 2011-03-31 11:26:23 -03:00
wanrouter Fix common misspellings 2011-03-31 11:26:23 -03:00
wimax
…
wireless Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next-2.6 into for-davem 2011-04-25 14:34:25 -04:00
x25 Fix common misspellings 2011-03-31 11:26:23 -03:00
xfrm inet: constify ip headers and in6_addr 2011-04-22 11:04:14 -07:00
Kconfig net: filter: Just In Time compiler for x86-64 2011-04-27 23:05:08 -07:00
Makefile net: Enter net/ipv6/ even if CONFIG_IPV6=n 2011-03-07 12:50:52 -08:00
TUNABLE
…
compat.c
…
nonet.c
…
socket.c Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2011-04-11 13:44:25 -07:00
sysctl_net.c
…