bpf: Add prog flag to struct bpf_ksym object

Adding 'prog' bool flag to 'struct bpf_ksym' to mark that
this object belongs to bpf_prog object.

This change allows having bpf_prog objects together with
other types (trampolines and dispatchers) in the single
bpf_tree. It's used when searching for bpf_prog exception
tables by the bpf_prog_ksym_find function, where we need
to get the bpf_prog pointer.

>From now we can safely add bpf_ksym support for trampoline
or dispatcher objects, because we can differentiate them
from bpf_prog objects.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200312195610.346362-9-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

include/linux/bpf.h

@@ -478,6 +478,7 @@ struct bpf_ksym {
 	char			 name[KSYM_NAME_LEN];
 	struct list_head	 lnode;
 	struct latch_tree_node	 tnode;
+	bool			 prog;
 };
 
 enum bpf_tramp_prog_type {