From: Andrii Nakryiko <andrii@kernel.org>
To: <bpf@vger.kernel.org>, <netdev@vger.kernel.org>, <ast@fb.com>,
<daniel@iogearbox.net>
Cc: <andrii@kernel.org>, <kernel-team@fb.com>
Subject: [PATCH bpf-next 3/3] tools/bpftool: auto-detect split BTFs in common cases
Date: Tue, 1 Dec 2020 22:52:43 -0800 [thread overview]
Message-ID: <20201202065244.530571-4-andrii@kernel.org> (raw)
In-Reply-To: <20201202065244.530571-1-andrii@kernel.org>
In case of working with module's split BTF from /sys/kernel/btf/*,
auto-substitute /sys/kernel/btf/vmlinux as the base BTF. This makes using
bpftool with module BTFs faster and simpler.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
---
tools/bpf/bpftool/btf.c | 25 +++++++++++++++++++++----
1 file changed, 21 insertions(+), 4 deletions(-)
diff --git a/tools/bpf/bpftool/btf.c b/tools/bpf/bpftool/btf.c
index bd46af6a61cc..94cd3bad5430 100644
--- a/tools/bpf/bpftool/btf.c
+++ b/tools/bpf/bpftool/btf.c
@@ -357,11 +357,13 @@ static int dump_btf_raw(const struct btf *btf,
dump_btf_type(btf, root_type_ids[i], t);
}
} else {
+ const struct btf *base;
int cnt = btf__get_nr_types(btf);
int start_id = 1;
- if (base_btf)
- start_id = btf__get_nr_types(base_btf) + 1;
+ base = btf__base_btf(btf);
+ if (base)
+ start_id = btf__get_nr_types(base) + 1;
for (i = start_id; i <= cnt; i++) {
t = btf__type_by_id(btf, i);
@@ -428,7 +430,7 @@ static int dump_btf_c(const struct btf *btf,
static int do_dump(int argc, char **argv)
{
- struct btf *btf = NULL;
+ struct btf *btf = NULL, *base = NULL;
__u32 root_type_ids[2];
int root_type_cnt = 0;
bool dump_c = false;
@@ -502,7 +504,21 @@ static int do_dump(int argc, char **argv)
}
NEXT_ARG();
} else if (is_prefix(src, "file")) {
- btf = btf__parse_split(*argv, base_btf);
+ const char sysfs_prefix[] = "/sys/kernel/btf/";
+ const char sysfs_vmlinux[] = "/sys/kernel/btf/vmlinux";
+
+ if (!base_btf &&
+ strncmp(*argv, sysfs_prefix, sizeof(sysfs_prefix) - 1) == 0 &&
+ strcmp(*argv, sysfs_vmlinux) != 0) {
+ base = btf__parse(sysfs_vmlinux, NULL);
+ if (libbpf_get_error(base)) {
+ p_err("failed to parse vmlinux BTF at '%s': %ld\n",
+ sysfs_vmlinux, libbpf_get_error(base));
+ base = NULL;
+ }
+ }
+
+ btf = btf__parse_split(*argv, base ?: base_btf);
if (IS_ERR(btf)) {
err = -PTR_ERR(btf);
btf = NULL;
@@ -567,6 +583,7 @@ static int do_dump(int argc, char **argv)
done:
close(fd);
btf__free(btf);
+ btf__free(base);
return err;
}
--
2.24.1
next prev parent reply other threads:[~2020-12-02 6:53 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-02 6:52 [PATCH bpf-next 0/3] bpftool: improve split BTF support Andrii Nakryiko
2020-12-02 6:52 ` [PATCH bpf-next 1/3] tools/bpftool: emit name <anon> for anonymous BTFs Andrii Nakryiko
2020-12-02 6:52 ` [PATCH bpf-next 2/3] libbpf: add base BTF accessor Andrii Nakryiko
2020-12-02 6:52 ` Andrii Nakryiko [this message]
2020-12-03 18:31 ` [PATCH bpf-next 0/3] bpftool: improve split BTF support Alexei Starovoitov
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