From fdbf5ddeb855a80831af2e5bb9db9218926e6789 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Thu, 6 May 2021 22:41:14 -0700
Subject: [PATCH] libbpf: Add per-file linker opts
For better future extensibility add per-file linker options. Currently
the set of available options is empty. This changes bpf_linker__add_file()
API, but it's not a breaking change as bpf_linker APIs hasn't been released
yet.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210507054119.270888-3-andrii@kernel.org
---
tools/bpf/bpftool/gen.c | 2 +-
tools/lib/bpf/libbpf.h | 10 +++++++++-
tools/lib/bpf/linker.c | 16 ++++++++++++----
3 files changed, 22 insertions(+), 6 deletions(-)
diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c
index 440a2fcb6441a..06fee4a2910a0 100644
--- a/tools/bpf/bpftool/gen.c
+++ b/tools/bpf/bpftool/gen.c
@@ -638,7 +638,7 @@ static int do_object(int argc, char **argv)
while (argc) {
file = GET_ARG();
- err = bpf_linker__add_file(linker, file);
+ err = bpf_linker__add_file(linker, file, NULL);
if (err) {
p_err("failed to link '%s': %s (%d)", file, strerror(err), err);
goto out;
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index bec4e6a6e31dd..3f3a247634593 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -768,10 +768,18 @@ struct bpf_linker_opts {
};
#define bpf_linker_opts__last_field sz
+struct bpf_linker_file_opts {
+ /* size of this struct, for forward/backward compatiblity */
+ size_t sz;
+};
+#define bpf_linker_file_opts__last_field sz
+
struct bpf_linker;
LIBBPF_API struct bpf_linker *bpf_linker__new(const char *filename, struct bpf_linker_opts *opts);
-LIBBPF_API int bpf_linker__add_file(struct bpf_linker *linker, const char *filename);
+LIBBPF_API int bpf_linker__add_file(struct bpf_linker *linker,
+ const char *filename,
+ const struct bpf_linker_file_opts *opts);
LIBBPF_API int bpf_linker__finalize(struct bpf_linker *linker);
LIBBPF_API void bpf_linker__free(struct bpf_linker *linker);
diff --git a/tools/lib/bpf/linker.c b/tools/lib/bpf/linker.c
index 9de084b1c6993..3b1fbc27be37a 100644
--- a/tools/lib/bpf/linker.c
+++ b/tools/lib/bpf/linker.c
@@ -158,7 +158,9 @@ struct bpf_linker {
static int init_output_elf(struct bpf_linker *linker, const char *file);
-static int linker_load_obj_file(struct bpf_linker *linker, const char *filename, struct src_obj *obj);
+static int linker_load_obj_file(struct bpf_linker *linker, const char *filename,
+ const struct bpf_linker_file_opts *opts,
+ struct src_obj *obj);
static int linker_sanity_check_elf(struct src_obj *obj);
static int linker_sanity_check_elf_symtab(struct src_obj *obj, struct src_sec *sec);
static int linker_sanity_check_elf_relos(struct src_obj *obj, struct src_sec *sec);
@@ -435,15 +437,19 @@ static int init_output_elf(struct bpf_linker *linker, const char *file)
return 0;
}
-int bpf_linker__add_file(struct bpf_linker *linker, const char *filename)
+int bpf_linker__add_file(struct bpf_linker *linker, const char *filename,
+ const struct bpf_linker_file_opts *opts)
{
struct src_obj obj = {};
int err = 0;
+ if (!OPTS_VALID(opts, bpf_linker_file_opts))
+ return -EINVAL;
+
if (!linker->elf)
return -EINVAL;
- err = err ?: linker_load_obj_file(linker, filename, &obj);
+ err = err ?: linker_load_obj_file(linker, filename, opts, &obj);
err = err ?: linker_append_sec_data(linker, &obj);
err = err ?: linker_append_elf_syms(linker, &obj);
err = err ?: linker_append_elf_relos(linker, &obj);
@@ -529,7 +535,9 @@ static struct src_sec *add_src_sec(struct src_obj *obj, const char *sec_name)
return sec;
}
-static int linker_load_obj_file(struct bpf_linker *linker, const char *filename, struct src_obj *obj)
+static int linker_load_obj_file(struct bpf_linker *linker, const char *filename,
+ const struct bpf_linker_file_opts *opts,
+ struct src_obj *obj)
{
#if __BYTE_ORDER == __LITTLE_ENDIAN
const int host_endianness = ELFDATA2LSB;
--
2.30.2