diff options
author | Alexei Starovoitov <ast@plumgrid.com> | 2014-10-24 01:41:08 (GMT) |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2014-10-27 23:09:59 (GMT) |
commit | f89b7755f517cdbb755d7543eef986ee9d54e654 (patch) | |
tree | bf491bea6418b0442900d864237e0028f7c35162 /kernel | |
parent | 8ae3c911b9efcca653c552a9c74957a6cb04a87d (diff) | |
download | linux-f89b7755f517cdbb755d7543eef986ee9d54e654.tar.xz |
bpf: split eBPF out of NET
introduce two configs:
- hidden CONFIG_BPF to select eBPF interpreter that classic socket filters
depend on
- visible CONFIG_BPF_SYSCALL (default off) that tracing and sockets can use
that solves several problems:
- tracing and others that wish to use eBPF don't need to depend on NET.
They can use BPF_SYSCALL to allow loading from userspace or select BPF
to use it directly from kernel in NET-less configs.
- in 3.18 programs cannot be attached to events yet, so don't force it on
- when the rest of eBPF infra is there in 3.19+, it's still useful to
switch it off to minimize kernel size
bloat-o-meter on x64 shows:
add/remove: 0/60 grow/shrink: 0/2 up/down: 0/-15601 (-15601)
tested with many different config combinations. Hopefully didn't miss anything.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/Makefile | 2 | ||||
-rw-r--r-- | kernel/bpf/Makefile | 6 | ||||
-rw-r--r-- | kernel/bpf/core.c | 9 |
3 files changed, 13 insertions, 4 deletions
diff --git a/kernel/Makefile b/kernel/Makefile index dc5c775..17ea6d4 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -86,7 +86,7 @@ obj-$(CONFIG_RING_BUFFER) += trace/ obj-$(CONFIG_TRACEPOINTS) += trace/ obj-$(CONFIG_IRQ_WORK) += irq_work.o obj-$(CONFIG_CPU_PM) += cpu_pm.o -obj-$(CONFIG_NET) += bpf/ +obj-$(CONFIG_BPF) += bpf/ obj-$(CONFIG_PERF_EVENTS) += events/ diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile index 4542723..0daf7f6 100644 --- a/kernel/bpf/Makefile +++ b/kernel/bpf/Makefile @@ -1,5 +1,5 @@ -obj-y := core.o syscall.o verifier.o - +obj-y := core.o +obj-$(CONFIG_BPF_SYSCALL) += syscall.o verifier.o ifdef CONFIG_TEST_BPF -obj-y += test_stub.o +obj-$(CONFIG_BPF_SYSCALL) += test_stub.o endif diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index f0c30c5..d6594e4 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -655,3 +655,12 @@ void bpf_prog_free(struct bpf_prog *fp) schedule_work(&aux->work); } EXPORT_SYMBOL_GPL(bpf_prog_free); + +/* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call + * skb_copy_bits(), so provide a weak definition of it for NET-less config. + */ +int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to, + int len) +{ + return -EFAULT; +} |