linux/samples
Alexei Starovoitov 3431205e03 bpf: make programs see skb->data == L2 for ingress and egress
eBPF programs attached to ingress and egress qdiscs see inconsistent skb->data.
For ingress L2 header is already pulled, whereas for egress it's present.
This is known to program writers which are currently forced to use
BPF_LL_OFF workaround.
Since programs don't change skb internal pointers it is safe to do
pull/push right around invocation of the program and earlier taps and
later pt->func() will not be affected.
Multiple taps via packet_rcv(), tpacket_rcv() are doing the same trick
around run_filter/BPF_PROG_RUN even if skb_shared.

This fix finally allows programs to use optimized LD_ABS/IND instructions
without BPF_LL_OFF for higher performance.
tc ingress + cls_bpf + samples/bpf/tcbpf1_kern.o
       w/o JIT   w/JIT
before  20.5     23.6 Mpps
after   21.8     26.6 Mpps

Old programs with BPF_LL_OFF will still work as-is.

We can now undo most of the earlier workaround commit:
a166151cbe ("bpf: fix bpf helpers to use skb->mac_header relative offsets")

Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-07 02:01:33 -07:00
..
bpf bpf: make programs see skb->data == L2 for ingress and egress 2015-06-07 02:01:33 -07:00
hidraw HID: samples/hidraw: make it possible to select device 2015-03-15 10:11:21 -04:00
hw_breakpoint perf: Add context field to perf_event 2011-07-01 11:06:38 +02:00
kdb kdb: Add kdb kernel module sample 2010-10-29 13:14:39 -05:00
kfifo kfifo API type safety 2013-11-15 09:32:23 +09:00
kobject samples/kobject: be explicit in the module license 2015-03-25 13:41:42 +01:00
kprobes kprobes: update jprobe_example.c for do_fork() change 2014-09-26 11:11:12 +02:00
livepatch livepatch: rename config to CONFIG_LIVEPATCH 2015-02-04 11:25:51 +01:00
pktgen pktgen: add benchmark script pktgen_bench_xmit_mode_netif_receive.sh 2015-05-22 23:59:17 -04:00
rpmsg misc: remove __dev* attributes. 2013-01-03 15:57:16 -08:00
seccomp samples/seccomp: improve label helper 2015-02-17 14:34:55 -08:00
trace_events tracing/samples: Update the trace-event-sample.h with TRACE_DEFINE_ENUM() 2015-04-08 09:39:58 -04:00
uhid HID: uhid: improve uhid example client 2013-09-04 11:35:14 +02:00
Kconfig livepatch: rename config to CONFIG_LIVEPATCH 2015-02-04 11:25:51 +01:00
Makefile livepatch: samples: add sample live patching module 2014-12-22 15:40:49 +01:00