On Wed, Jul 21, 2021 at 8:38 AM Quentin Monnet <quentin@xxxxxxxxxxxxx> wrote:
>
> Replace the calls to deprecated function btf__get_from_id() with calls
> to btf__load_from_kernel_by_id() in tools/ (bpftool, perf, selftests).
> Update the surrounding code accordingly (instead of passing a pointer to
> the btf struct, get it as a return value from the function). Also make
> sure that btf__free() is called on the pointer after use.
>
> v2:
> - Given that btf__load_from_kernel_by_id() has changed since v1, adapt
> the code accordingly instead of just renaming the function. Also add a
> few calls to btf__free() when necessary.
>
> Signed-off-by: Quentin Monnet <quentin@xxxxxxxxxxxxx>
> Acked-by: John Fastabend <john.fastabend@xxxxxxxxx>
> ---
> tools/bpf/bpftool/btf.c | 8 ++----
> tools/bpf/bpftool/btf_dumper.c | 6 ++--
> tools/bpf/bpftool/map.c | 16 +++++------
> tools/bpf/bpftool/prog.c | 29 ++++++++++++++------
> tools/perf/util/bpf-event.c | 11 ++++----
> tools/perf/util/bpf_counter.c | 12 ++++++--
> tools/testing/selftests/bpf/prog_tests/btf.c | 4 ++-
> 7 files changed, 51 insertions(+), 35 deletions(-)
>
[...]
> diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c
> index 09ae0381205b..12787758ce03 100644
> --- a/tools/bpf/bpftool/map.c
> +++ b/tools/bpf/bpftool/map.c
> @@ -805,12 +805,11 @@ static struct btf *get_map_kv_btf(const struct bpf_map_info *info)
> }
> return btf_vmlinux;
> } 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);
> + if (libbpf_get_error(btf)) {
> p_err("failed to get btf");
> - btf = err ? ERR_PTR(err) : ERR_PTR(-ESRCH);
> + if (!btf)
> + btf = ERR_PTR(-ESRCH);
why not do a simpler (less conditionals)
err = libbpf_get_error(btf);
if (err) {
btf = ERR_PTR(err);
}
?
> }
> }
>
> @@ -1039,11 +1038,10 @@ 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;
> }
[...]
>
> 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);
> +
warrants a Fixes: tag?
> 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);
and another Fixes? :) and two more below
> free(info_linear);
> return name;
> }
[...]
