Commit 49f4e672 authored by Jiri Olsa's avatar Jiri Olsa Committed by Alexei Starovoitov
Browse files

bpf: Use BTF_ID to resolve bpf_ctx_convert struct 



This way the ID is resolved during compile time,
and we can remove the runtime name search.

Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Tested-by: default avatarAndrii Nakryiko <andriin@fb.com>
Acked-by: default avatarAndrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200711215329.41165-7-jolsa@kernel.org
parent 138b9a05

kernel/bpf/btf.c

+6 −8
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
#include <linux/sort.h>

#include <linux/bpf_verifier.h>

#include <linux/btf.h>

#include <linux/btf_ids.h>

#include <linux/skmsg.h>

#include <linux/perf_event.h>

#include <net/sock.h>
@@ -3621,12 +3622,15 @@ static int btf_translate_to_vmlinux(struct bpf_verifier_log *log, 
	return kern_ctx_type->type;

}



BTF_ID_LIST(bpf_ctx_convert_btf_id)

BTF_ID(struct, bpf_ctx_convert)



struct btf *btf_parse_vmlinux(void)

{

	struct btf_verifier_env *env = NULL;

	struct bpf_verifier_log *log;

	struct btf *btf = NULL;

	int err, btf_id;

	int err;



	env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN);

	if (!env)
@@ -3659,14 +3663,8 @@ struct btf *btf_parse_vmlinux(void) 
	if (err)

		goto errout;



	/* find struct bpf_ctx_convert for type checking later */

	btf_id = btf_find_by_name_kind(btf, "bpf_ctx_convert", BTF_KIND_STRUCT);

	if (btf_id < 0) {

		err = btf_id;

		goto errout;

	}

	/* btf_parse_vmlinux() runs under bpf_verifier_lock */

	bpf_ctx_convert.t = btf_type_by_id(btf, btf_id);

	bpf_ctx_convert.t = btf_type_by_id(btf, bpf_ctx_convert_btf_id[0]);



	/* find bpf map structs for map_ptr access checking */

	err = btf_vmlinux_map_ids_init(btf, log);