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authorAlexei Starovoitov <ast@plumgrid.com>2014-10-23 18:41:08 -0700
committerDavid S. Miller <davem@davemloft.net>2014-10-27 19:09:59 -0400
commitf89b7755f517cdbb755d7543eef986ee9d54e654 (patch)
treebf491bea6418b0442900d864237e0028f7c35162 /kernel/bpf
parent8ae3c911b9efcca653c552a9c74957a6cb04a87d (diff)
downloadlinux-sh-f89b7755f517cdbb755d7543eef986ee9d54e654.tar.gz
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/bpf')
-rw-r--r--kernel/bpf/Makefile6
-rw-r--r--kernel/bpf/core.c9
2 files changed, 12 insertions, 3 deletions
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;
+}