Merge branch 'libbpf: rename btf__get_from_id() and btf__load() APIs, support split BTF'
Quentin Monnet says:
====================
As part of the effort to move towards a v1.0 for libbpf [0], this set
improves some confusing function names related to BTF loading from and to
the kernel:
- btf__load() becomes btf__load_into_kernel().
- btf__get_from_id becomes btf__load_from_kernel_by_id().
- A new version btf__load_from_kernel_by_id_split() extends the former to
add support for split BTF.
The last patch is a trivial change to bpftool to add support for dumping
split BTF objects by referencing them by their id (and not only by their
BTF path).
[0] https://github.com/libbpf/libbpf/wiki/Libbpf:-the-road-to-v1.0#btfh-apis
v3:
- Use libbpf_err_ptr() in btf__load_from_kernel_by_id(), ERR_PTR() in
bpftool's get_map_kv_btf().
- Move the definition of btf__load_from_kernel_by_id() closer to the
btf__parse() group in btf.h (move the legacy function with it).
- Fix a bug on the return value in libbpf_find_prog_btf_id(), as a new
patch.
- Move the btf__free() fixes to their own patch.
- Add "Fixes:" tags to relevant patches.
v2:
- Remove deprecation marking of legacy functions (patch 4/6 from v1).
- Make btf__load_from_kernel_by_id{,_split}() return the btf struct, adjust
surrounding code and call btf__free() when missing.
- Add new functions to v0.5.0 API (and not v0.6.0).
====================
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
diff --git a/tools/bpf/bpftool/btf.c b/tools/bpf/bpftool/btf.c
index 385d5c9..0ce3643 100644
--- a/tools/bpf/bpftool/btf.c
+++ b/tools/bpf/bpftool/btf.c
@@ -580,16 +580,12 @@ static int do_dump(int argc, char **argv)
}
if (!btf) {
- err = btf__get_from_id(btf_id, &btf);
+ btf = btf__load_from_kernel_by_id_split(btf_id, base_btf);
+ err = libbpf_get_error(btf);
if (err) {
p_err("get btf by id (%u): %s", btf_id, strerror(err));
goto done;
}
- if (!btf) {
- err = -ENOENT;
- p_err("can't find btf with ID (%u)", btf_id);
- goto done;
- }
}
if (dump_c) {
diff --git a/tools/bpf/bpftool/btf_dumper.c b/tools/bpf/bpftool/btf_dumper.c
index 7ca54d0..9c25286 100644
--- a/tools/bpf/bpftool/btf_dumper.c
+++ b/tools/bpf/bpftool/btf_dumper.c
@@ -64,8 +64,10 @@ static int dump_prog_id_as_func_ptr(const struct btf_dumper *d,
}
info = &prog_info->info;
- if (!info->btf_id || !info->nr_func_info ||
- btf__get_from_id(info->btf_id, &prog_btf))
+ if (!info->btf_id || !info->nr_func_info)
+ goto print;
+ prog_btf = btf__load_from_kernel_by_id(info->btf_id);
+ if (libbpf_get_error(prog_btf))
goto print;
finfo = u64_to_ptr(info->func_info);
func_type = btf__type_by_id(prog_btf, finfo->type_id);
diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c
index 09ae038..7e7f748 100644
--- a/tools/bpf/bpftool/map.c
+++ b/tools/bpf/bpftool/map.c
@@ -807,10 +807,11 @@ static struct btf *get_map_kv_btf(const struct bpf_map_info *info)
} else if (info->btf_value_type_id) {
int err;
- err = btf__get_from_id(info->btf_id, &btf);
- if (err || !btf) {
+ btf = btf__load_from_kernel_by_id(info->btf_id);
+ err = libbpf_get_error(btf);
+ if (err) {
p_err("failed to get btf");
- btf = err ? ERR_PTR(err) : ERR_PTR(-ESRCH);
+ btf = ERR_PTR(err);
}
}
@@ -1039,11 +1040,10 @@ static void print_key_value(struct bpf_map_info *info, void *key,
void *value)
{
json_writer_t *btf_wtr;
- struct btf *btf = NULL;
- int err;
+ struct btf *btf;
- err = btf__get_from_id(info->btf_id, &btf);
- if (err) {
+ btf = btf__load_from_kernel_by_id(info->btf_id);
+ if (libbpf_get_error(btf)) {
p_err("failed to get btf");
return;
}
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index cc48726..b1996b8 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -249,10 +249,10 @@ static void show_prog_metadata(int fd, __u32 num_maps)
struct bpf_map_info map_info;
struct btf_var_secinfo *vsi;
bool printed_header = false;
- struct btf *btf = NULL;
unsigned int i, vlen;
void *value = NULL;
const char *name;
+ struct btf *btf;
int err;
if (!num_maps)
@@ -263,8 +263,8 @@ static void show_prog_metadata(int fd, __u32 num_maps)
if (!value)
return;
- err = btf__get_from_id(map_info.btf_id, &btf);
- if (err || !btf)
+ btf = btf__load_from_kernel_by_id(map_info.btf_id);
+ if (libbpf_get_error(btf))
goto out_free;
t_datasec = btf__type_by_id(btf, map_info.btf_value_type_id);
@@ -646,9 +646,12 @@ prog_dump(struct bpf_prog_info *info, enum dump_mode mode,
member_len = info->xlated_prog_len;
}
- if (info->btf_id && btf__get_from_id(info->btf_id, &btf)) {
- p_err("failed to get btf");
- return -1;
+ if (info->btf_id) {
+ btf = btf__load_from_kernel_by_id(info->btf_id);
+ if (libbpf_get_error(btf)) {
+ p_err("failed to get btf");
+ return -1;
+ }
}
func_info = u64_to_ptr(info->func_info);
@@ -781,6 +784,8 @@ prog_dump(struct bpf_prog_info *info, enum dump_mode mode,
kernel_syms_destroy(&dd);
}
+ btf__free(btf);
+
return 0;
}
@@ -2002,8 +2007,8 @@ static char *profile_target_name(int tgt_fd)
struct bpf_prog_info_linear *info_linear;
struct bpf_func_info *func_info;
const struct btf_type *t;
+ struct btf *btf = NULL;
char *name = NULL;
- struct btf *btf;
info_linear = bpf_program__get_prog_info_linear(
tgt_fd, 1UL << BPF_PROG_INFO_FUNC_INFO);
@@ -2012,12 +2017,17 @@ static char *profile_target_name(int tgt_fd)
return NULL;
}
- if (info_linear->info.btf_id == 0 ||
- btf__get_from_id(info_linear->info.btf_id, &btf)) {
+ if (info_linear->info.btf_id == 0) {
p_err("prog FD %d doesn't have valid btf", tgt_fd);
goto out;
}
+ btf = btf__load_from_kernel_by_id(info_linear->info.btf_id);
+ if (libbpf_get_error(btf)) {
+ p_err("failed to load btf for prog FD %d", tgt_fd);
+ goto out;
+ }
+
func_info = u64_to_ptr(info_linear->info.func_info);
t = btf__type_by_id(btf, func_info[0].type_id);
if (!t) {
@@ -2027,6 +2037,7 @@ static char *profile_target_name(int tgt_fd)
}
name = strdup(btf__name_by_offset(btf, t->name_off));
out:
+ btf__free(btf);
free(info_linear);
return name;
}
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index b46760b9..cafa4f6 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -1180,7 +1180,7 @@ int btf__finalize_data(struct bpf_object *obj, struct btf *btf)
static void *btf_get_raw_data(const struct btf *btf, __u32 *size, bool swap_endian);
-int btf__load(struct btf *btf)
+int btf__load_into_kernel(struct btf *btf)
{
__u32 log_buf_size = 0, raw_size;
char *log_buf = NULL;
@@ -1228,6 +1228,7 @@ int btf__load(struct btf *btf)
free(log_buf);
return libbpf_err(err);
}
+int btf__load(struct btf *) __attribute__((alias("btf__load_into_kernel")));
int btf__fd(const struct btf *btf)
{
@@ -1382,21 +1383,35 @@ struct btf *btf_get_from_fd(int btf_fd, struct btf *base_btf)
return btf;
}
+struct btf *btf__load_from_kernel_by_id_split(__u32 id, struct btf *base_btf)
+{
+ struct btf *btf;
+ int btf_fd;
+
+ btf_fd = bpf_btf_get_fd_by_id(id);
+ if (btf_fd < 0)
+ return libbpf_err_ptr(-errno);
+
+ btf = btf_get_from_fd(btf_fd, base_btf);
+ close(btf_fd);
+
+ return libbpf_ptr(btf);
+}
+
+struct btf *btf__load_from_kernel_by_id(__u32 id)
+{
+ return btf__load_from_kernel_by_id_split(id, NULL);
+}
+
int btf__get_from_id(__u32 id, struct btf **btf)
{
struct btf *res;
- int err, btf_fd;
+ int err;
*btf = NULL;
- btf_fd = bpf_btf_get_fd_by_id(id);
- if (btf_fd < 0)
- return libbpf_err(-errno);
-
- res = btf_get_from_fd(btf_fd, NULL);
+ res = btf__load_from_kernel_by_id(id);
err = libbpf_get_error(res);
- close(btf_fd);
-
if (err)
return libbpf_err(err);
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index 374e9f1..596a42c 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -44,8 +44,13 @@ LIBBPF_API struct btf *btf__parse_elf_split(const char *path, struct btf *base_b
LIBBPF_API struct btf *btf__parse_raw(const char *path);
LIBBPF_API struct btf *btf__parse_raw_split(const char *path, struct btf *base_btf);
+LIBBPF_API struct btf *btf__load_from_kernel_by_id(__u32 id);
+LIBBPF_API struct btf *btf__load_from_kernel_by_id_split(__u32 id, struct btf *base_btf);
+LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf);
+
LIBBPF_API int btf__finalize_data(struct bpf_object *obj, struct btf *btf);
LIBBPF_API int btf__load(struct btf *btf);
+LIBBPF_API int btf__load_into_kernel(struct btf *btf);
LIBBPF_API __s32 btf__find_by_name(const struct btf *btf,
const char *type_name);
LIBBPF_API __s32 btf__find_by_name_kind(const struct btf *btf,
@@ -66,7 +71,6 @@ LIBBPF_API void btf__set_fd(struct btf *btf, int fd);
LIBBPF_API const void *btf__get_raw_data(const struct btf *btf, __u32 *size);
LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset);
LIBBPF_API const char *btf__str_by_offset(const struct btf *btf, __u32 offset);
-LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf);
LIBBPF_API int btf__get_map_kv_tids(const struct btf *btf, const char *map_name,
__u32 expected_key_size,
__u32 expected_value_size,
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index a1ca6fb..3138831 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -2769,7 +2769,7 @@ static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj)
*/
btf__set_fd(kern_btf, 0);
} else {
- err = btf__load(kern_btf);
+ err = btf__load_into_kernel(kern_btf);
}
if (sanitize) {
if (!err) {
@@ -8316,8 +8316,8 @@ static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd)
{
struct bpf_prog_info_linear *info_linear;
struct bpf_prog_info *info;
- struct btf *btf = NULL;
- int err = -EINVAL;
+ struct btf *btf;
+ int err;
info_linear = bpf_program__get_prog_info_linear(attach_prog_fd, 0);
err = libbpf_get_error(info_linear);
@@ -8326,12 +8326,15 @@ static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd)
attach_prog_fd);
return err;
}
+
+ err = -EINVAL;
info = &info_linear->info;
if (!info->btf_id) {
pr_warn("The target program doesn't have BTF\n");
goto out;
}
- if (btf__get_from_id(info->btf_id, &btf)) {
+ btf = btf__load_from_kernel_by_id(info->btf_id);
+ if (libbpf_get_error(btf)) {
pr_warn("Failed to get BTF of the program\n");
goto out;
}
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index c240d48..5aca368 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -375,6 +375,9 @@
bpf_map_lookup_and_delete_elem_flags;
bpf_program__attach_kprobe_opts;
bpf_object__gen_loader;
+ btf__load_from_kernel_by_id;
+ btf__load_from_kernel_by_id_split;
+ btf__load_into_kernel;
btf_dump__dump_type_data;
libbpf_set_strict_mode;
} LIBBPF_0.4.0;
diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
index cdecda1..996d025 100644
--- a/tools/perf/util/bpf-event.c
+++ b/tools/perf/util/bpf-event.c
@@ -223,10 +223,10 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
free(info_linear);
return -1;
}
- if (btf__get_from_id(info->btf_id, &btf)) {
+ btf = btf__load_from_kernel_by_id(info->btf_id);
+ if (libbpf_get_error(btf)) {
pr_debug("%s: failed to get BTF of id %u, aborting\n", __func__, info->btf_id);
err = -1;
- btf = NULL;
goto out;
}
perf_env__fetch_btf(env, info->btf_id, btf);
@@ -296,7 +296,7 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
out:
free(info_linear);
- free(btf);
+ btf__free(btf);
return err ? -1 : 0;
}
@@ -478,7 +478,8 @@ static void perf_env__add_bpf_info(struct perf_env *env, u32 id)
if (btf_id == 0)
goto out;
- if (btf__get_from_id(btf_id, &btf)) {
+ btf = btf__load_from_kernel_by_id(btf_id);
+ if (libbpf_get_error(btf)) {
pr_debug("%s: failed to get BTF of id %u, aborting\n",
__func__, btf_id);
goto out;
@@ -486,7 +487,7 @@ static void perf_env__add_bpf_info(struct perf_env *env, u32 id)
perf_env__fetch_btf(env, btf_id, btf);
out:
- free(btf);
+ btf__free(btf);
close(fd);
}
diff --git a/tools/perf/util/bpf_counter.c b/tools/perf/util/bpf_counter.c
index 8150e03..ba0f208 100644
--- a/tools/perf/util/bpf_counter.c
+++ b/tools/perf/util/bpf_counter.c
@@ -64,8 +64,8 @@ static char *bpf_target_prog_name(int tgt_fd)
struct bpf_prog_info_linear *info_linear;
struct bpf_func_info *func_info;
const struct btf_type *t;
+ struct btf *btf = NULL;
char *name = NULL;
- struct btf *btf;
info_linear = bpf_program__get_prog_info_linear(
tgt_fd, 1UL << BPF_PROG_INFO_FUNC_INFO);
@@ -74,12 +74,17 @@ static char *bpf_target_prog_name(int tgt_fd)
return NULL;
}
- if (info_linear->info.btf_id == 0 ||
- btf__get_from_id(info_linear->info.btf_id, &btf)) {
+ if (info_linear->info.btf_id == 0) {
pr_debug("prog FD %d doesn't have valid btf\n", tgt_fd);
goto out;
}
+ btf = btf__load_from_kernel_by_id(info_linear->info.btf_id);
+ if (libbpf_get_error(btf)) {
+ pr_debug("failed to load btf for prog FD %d\n", tgt_fd);
+ goto out;
+ }
+
func_info = u64_to_ptr(info_linear->info.func_info);
t = btf__type_by_id(btf, func_info[0].type_id);
if (!t) {
@@ -89,6 +94,7 @@ static char *bpf_target_prog_name(int tgt_fd)
}
name = strdup(btf__name_by_offset(btf, t->name_off));
out:
+ btf__free(btf);
free(info_linear);
return name;
}
diff --git a/tools/testing/selftests/bpf/prog_tests/btf.c b/tools/testing/selftests/bpf/prog_tests/btf.c
index 857e3f2..649f873 100644
--- a/tools/testing/selftests/bpf/prog_tests/btf.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf.c
@@ -4350,7 +4350,8 @@ static void do_test_file(unsigned int test_num)
goto done;
}
- err = btf__get_from_id(info.btf_id, &btf);
+ btf = btf__load_from_kernel_by_id(info.btf_id);
+ err = libbpf_get_error(btf);
if (CHECK(err, "cannot get btf from kernel, err: %d", err))
goto done;
@@ -4386,6 +4387,7 @@ static void do_test_file(unsigned int test_num)
fprintf(stderr, "OK");
done:
+ btf__free(btf);
free(func_info);
bpf_object__close(obj);
}