bpf: Add initial poke descriptor table for jit images

Add initial poke table data structures and management to the BPF
prog that can later be used by JITs. Also add an instance of poke
specific data for tail call maps; plan for later work is to extend
this also for BPF static keys.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/1db285ec2ea4207ee0455b3f8e191a4fc58b9ade.1574452833.git.daniel@iogearbox.net

1 files changed, 10 insertions, 0 deletions

diff --git a/include/linux/filter.h b/include/linux/filter.h
index ad80e9c6111c..796b60d8cc6c 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -952,6 +952,9 @@ void *bpf_jit_alloc_exec(unsigned long size);
 void bpf_jit_free_exec(void *addr);
 void bpf_jit_free(struct bpf_prog *fp);
 
+int bpf_jit_add_poke_descriptor(struct bpf_prog *prog,
+				struct bpf_jit_poke_descriptor *poke);
+
 int bpf_jit_get_func_addr(const struct bpf_prog *prog,
 			  const struct bpf_insn *insn, bool extra_pass,
 			  u64 *func_addr, bool *func_addr_fixed);
@@ -1055,6 +1058,13 @@ static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
 	return false;
 }
 
+static inline int
+bpf_jit_add_poke_descriptor(struct bpf_prog *prog,
+			    struct bpf_jit_poke_descriptor *poke)
+{
+	return -ENOTSUPP;
+}
+
 static inline void bpf_jit_free(struct bpf_prog *fp)
 {
 	bpf_prog_unlock_free(fp);