From f89b7755f517cdbb755d7543eef986ee9d54e654 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Thu, 23 Oct 2014 18:41:08 -0700 Subject: 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 Acked-by: Daniel Borkmann Signed-off-by: David S. Miller --- kernel/bpf/Makefile | 6 +++--- kernel/bpf/core.c | 9 +++++++++ 2 files changed, 12 insertions(+), 3 deletions(-) (limited to 'kernel/bpf') diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile index 45427239f375..0daf7f6ae7df 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 f0c30c59b317..d6594e457a25 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; +} -- cgit v1.2.3-59-g8ed1b