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-rw-r--r--tools/bpf/bpftool/Documentation/bpftool-btf.rst7
-rw-r--r--tools/bpf/bpftool/bash-completion/bpftool20
-rw-r--r--tools/bpf/bpftool/btf.c342
3 files changed, 363 insertions, 6 deletions
diff --git a/tools/bpf/bpftool/Documentation/bpftool-btf.rst b/tools/bpf/bpftool/Documentation/bpftool-btf.rst
index 6694a0fc8f99..39615f8e145b 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-btf.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-btf.rst
@@ -19,6 +19,7 @@ SYNOPSIS
BTF COMMANDS
=============
+| **bpftool** **btf** { **show** | **list** } [**id** *BTF_ID*]
| **bpftool** **btf dump** *BTF_SRC* [**format** *FORMAT*]
| **bpftool** **btf help**
|
@@ -29,6 +30,12 @@ BTF COMMANDS
DESCRIPTION
===========
+ **bpftool btf { show | list }** [**id** *BTF_ID*]
+ Show information about loaded BTF objects. If a BTF ID is
+ specified, show information only about given BTF object,
+ otherwise list all BTF objects currently loaded on the
+ system.
+
**bpftool btf dump** *BTF_SRC*
Dump BTF entries from a given *BTF_SRC*.
diff --git a/tools/bpf/bpftool/bash-completion/bpftool b/tools/bpf/bpftool/bash-completion/bpftool
index 4549fd424069..2ffd351f9dbf 100644
--- a/tools/bpf/bpftool/bash-completion/bpftool
+++ b/tools/bpf/bpftool/bash-completion/bpftool
@@ -73,8 +73,8 @@ _bpftool_get_prog_tags()
_bpftool_get_btf_ids()
{
- COMPREPLY+=( $( compgen -W "$( bpftool -jp prog 2>&1 | \
- command sed -n 's/.*"btf_id": \(.*\),\?$/\1/p' )" -- "$cur" ) )
+ COMPREPLY+=( $( compgen -W "$( bpftool -jp btf 2>&1 | \
+ command sed -n 's/.*"id": \(.*\),$/\1/p' )" -- "$cur" ) )
}
_bpftool_get_obj_map_names()
@@ -670,7 +670,7 @@ _bpftool()
map)
_bpftool_get_map_ids
;;
- dump)
+ $command)
_bpftool_get_btf_ids
;;
esac
@@ -698,9 +698,21 @@ _bpftool()
;;
esac
;;
+ show|list)
+ case $prev in
+ $command)
+ COMPREPLY+=( $( compgen -W "id" -- "$cur" ) )
+ ;;
+ id)
+ _bpftool_get_btf_ids
+ ;;
+ esac
+ return 0
+ ;;
*)
[[ $prev == $object ]] && \
- COMPREPLY=( $( compgen -W 'dump help' -- "$cur" ) )
+ COMPREPLY=( $( compgen -W 'dump help show list' \
+ -- "$cur" ) )
;;
esac
;;
diff --git a/tools/bpf/bpftool/btf.c b/tools/bpf/bpftool/btf.c
index 8805637f1a7e..9a9376d1d3df 100644
--- a/tools/bpf/bpftool/btf.c
+++ b/tools/bpf/bpftool/btf.c
@@ -11,6 +11,7 @@
#include <bpf.h>
#include <libbpf.h>
#include <linux/btf.h>
+#include <linux/hashtable.h>
#include "btf.h"
#include "json_writer.h"
@@ -35,6 +36,16 @@ static const char * const btf_kind_str[NR_BTF_KINDS] = {
[BTF_KIND_DATASEC] = "DATASEC",
};
+struct btf_attach_table {
+ DECLARE_HASHTABLE(table, 16);
+};
+
+struct btf_attach_point {
+ __u32 obj_id;
+ __u32 btf_id;
+ struct hlist_node hash;
+};
+
static const char *btf_int_enc_str(__u8 encoding)
{
switch (encoding) {
@@ -522,6 +533,330 @@ done:
return err;
}
+static int btf_parse_fd(int *argc, char ***argv)
+{
+ unsigned int id;
+ char *endptr;
+ int fd;
+
+ if (!is_prefix(*argv[0], "id")) {
+ p_err("expected 'id', got: '%s'?", **argv);
+ return -1;
+ }
+ NEXT_ARGP();
+
+ id = strtoul(**argv, &endptr, 0);
+ if (*endptr) {
+ p_err("can't parse %s as ID", **argv);
+ return -1;
+ }
+ NEXT_ARGP();
+
+ fd = bpf_btf_get_fd_by_id(id);
+ if (fd < 0)
+ p_err("can't get BTF object by id (%u): %s",
+ id, strerror(errno));
+
+ return fd;
+}
+
+static void delete_btf_table(struct btf_attach_table *tab)
+{
+ struct btf_attach_point *obj;
+ struct hlist_node *tmp;
+
+ unsigned int bkt;
+
+ hash_for_each_safe(tab->table, bkt, tmp, obj, hash) {
+ hash_del(&obj->hash);
+ free(obj);
+ }
+}
+
+static int
+build_btf_type_table(struct btf_attach_table *tab, enum bpf_obj_type type,
+ void *info, __u32 *len)
+{
+ static const char * const names[] = {
+ [BPF_OBJ_UNKNOWN] = "unknown",
+ [BPF_OBJ_PROG] = "prog",
+ [BPF_OBJ_MAP] = "map",
+ };
+ struct btf_attach_point *obj_node;
+ __u32 btf_id, id = 0;
+ int err;
+ int fd;
+
+ while (true) {
+ switch (type) {
+ case BPF_OBJ_PROG:
+ err = bpf_prog_get_next_id(id, &id);
+ break;
+ case BPF_OBJ_MAP:
+ err = bpf_map_get_next_id(id, &id);
+ break;
+ default:
+ err = -1;
+ p_err("unexpected object type: %d", type);
+ goto err_free;
+ }
+ if (err) {
+ if (errno == ENOENT) {
+ err = 0;
+ break;
+ }
+ p_err("can't get next %s: %s%s", names[type],
+ strerror(errno),
+ errno == EINVAL ? " -- kernel too old?" : "");
+ goto err_free;
+ }
+
+ switch (type) {
+ case BPF_OBJ_PROG:
+ fd = bpf_prog_get_fd_by_id(id);
+ break;
+ case BPF_OBJ_MAP:
+ fd = bpf_map_get_fd_by_id(id);
+ break;
+ default:
+ err = -1;
+ p_err("unexpected object type: %d", type);
+ goto err_free;
+ }
+ if (fd < 0) {
+ if (errno == ENOENT)
+ continue;
+ p_err("can't get %s by id (%u): %s", names[type], id,
+ strerror(errno));
+ err = -1;
+ goto err_free;
+ }
+
+ memset(info, 0, *len);
+ err = bpf_obj_get_info_by_fd(fd, info, len);
+ close(fd);
+ if (err) {
+ p_err("can't get %s info: %s", names[type],
+ strerror(errno));
+ goto err_free;
+ }
+
+ switch (type) {
+ case BPF_OBJ_PROG:
+ btf_id = ((struct bpf_prog_info *)info)->btf_id;
+ break;
+ case BPF_OBJ_MAP:
+ btf_id = ((struct bpf_map_info *)info)->btf_id;
+ break;
+ default:
+ err = -1;
+ p_err("unexpected object type: %d", type);
+ goto err_free;
+ }
+ if (!btf_id)
+ continue;
+
+ obj_node = calloc(1, sizeof(*obj_node));
+ if (!obj_node) {
+ p_err("failed to allocate memory: %s", strerror(errno));
+ goto err_free;
+ }
+
+ obj_node->obj_id = id;
+ obj_node->btf_id = btf_id;
+ hash_add(tab->table, &obj_node->hash, obj_node->btf_id);
+ }
+
+ return 0;
+
+err_free:
+ delete_btf_table(tab);
+ return err;
+}
+
+static int
+build_btf_tables(struct btf_attach_table *btf_prog_table,
+ struct btf_attach_table *btf_map_table)
+{
+ struct bpf_prog_info prog_info;
+ __u32 prog_len = sizeof(prog_info);
+ struct bpf_map_info map_info;
+ __u32 map_len = sizeof(map_info);
+ int err = 0;
+
+ err = build_btf_type_table(btf_prog_table, BPF_OBJ_PROG, &prog_info,
+ &prog_len);
+ if (err)
+ return err;
+
+ err = build_btf_type_table(btf_map_table, BPF_OBJ_MAP, &map_info,
+ &map_len);
+ if (err) {
+ delete_btf_table(btf_prog_table);
+ return err;
+ }
+
+ return 0;
+}
+
+static void
+show_btf_plain(struct bpf_btf_info *info, int fd,
+ struct btf_attach_table *btf_prog_table,
+ struct btf_attach_table *btf_map_table)
+{
+ struct btf_attach_point *obj;
+ int n;
+
+ printf("%u: ", info->id);
+ printf("size %uB", info->btf_size);
+
+ n = 0;
+ hash_for_each_possible(btf_prog_table->table, obj, hash, info->id) {
+ if (obj->btf_id == info->id)
+ printf("%s%u", n++ == 0 ? " prog_ids " : ",",
+ obj->obj_id);
+ }
+
+ n = 0;
+ hash_for_each_possible(btf_map_table->table, obj, hash, info->id) {
+ if (obj->btf_id == info->id)
+ printf("%s%u", n++ == 0 ? " map_ids " : ",",
+ obj->obj_id);
+ }
+
+ printf("\n");
+}
+
+static void
+show_btf_json(struct bpf_btf_info *info, int fd,
+ struct btf_attach_table *btf_prog_table,
+ struct btf_attach_table *btf_map_table)
+{
+ struct btf_attach_point *obj;
+
+ jsonw_start_object(json_wtr); /* btf object */
+ jsonw_uint_field(json_wtr, "id", info->id);
+ jsonw_uint_field(json_wtr, "size", info->btf_size);
+
+ jsonw_name(json_wtr, "prog_ids");
+ jsonw_start_array(json_wtr); /* prog_ids */
+ hash_for_each_possible(btf_prog_table->table, obj, hash,
+ info->id) {
+ if (obj->btf_id == info->id)
+ jsonw_uint(json_wtr, obj->obj_id);
+ }
+ jsonw_end_array(json_wtr); /* prog_ids */
+
+ jsonw_name(json_wtr, "map_ids");
+ jsonw_start_array(json_wtr); /* map_ids */
+ hash_for_each_possible(btf_map_table->table, obj, hash,
+ info->id) {
+ if (obj->btf_id == info->id)
+ jsonw_uint(json_wtr, obj->obj_id);
+ }
+ jsonw_end_array(json_wtr); /* map_ids */
+ jsonw_end_object(json_wtr); /* btf object */
+}
+
+static int
+show_btf(int fd, struct btf_attach_table *btf_prog_table,
+ struct btf_attach_table *btf_map_table)
+{
+ struct bpf_btf_info info = {};
+ __u32 len = sizeof(info);
+ int err;
+
+ err = bpf_obj_get_info_by_fd(fd, &info, &len);
+ if (err) {
+ p_err("can't get BTF object info: %s", strerror(errno));
+ return -1;
+ }
+
+ if (json_output)
+ show_btf_json(&info, fd, btf_prog_table, btf_map_table);
+ else
+ show_btf_plain(&info, fd, btf_prog_table, btf_map_table);
+
+ return 0;
+}
+
+static int do_show(int argc, char **argv)
+{
+ struct btf_attach_table btf_prog_table;
+ struct btf_attach_table btf_map_table;
+ int err, fd = -1;
+ __u32 id = 0;
+
+ if (argc == 2) {
+ fd = btf_parse_fd(&argc, &argv);
+ if (fd < 0)
+ return -1;
+ }
+
+ if (argc) {
+ if (fd >= 0)
+ close(fd);
+ return BAD_ARG();
+ }
+
+ hash_init(btf_prog_table.table);
+ hash_init(btf_map_table.table);
+ err = build_btf_tables(&btf_prog_table, &btf_map_table);
+ if (err) {
+ if (fd >= 0)
+ close(fd);
+ return err;
+ }
+
+ if (fd >= 0) {
+ err = show_btf(fd, &btf_prog_table, &btf_map_table);
+ close(fd);
+ goto exit_free;
+ }
+
+ if (json_output)
+ jsonw_start_array(json_wtr); /* root array */
+
+ while (true) {
+ err = bpf_btf_get_next_id(id, &id);
+ if (err) {
+ if (errno == ENOENT) {
+ err = 0;
+ break;
+ }
+ p_err("can't get next BTF object: %s%s",
+ strerror(errno),
+ errno == EINVAL ? " -- kernel too old?" : "");
+ err = -1;
+ break;
+ }
+
+ fd = bpf_btf_get_fd_by_id(id);
+ if (fd < 0) {
+ if (errno == ENOENT)
+ continue;
+ p_err("can't get BTF object by id (%u): %s",
+ id, strerror(errno));
+ err = -1;
+ break;
+ }
+
+ err = show_btf(fd, &btf_prog_table, &btf_map_table);
+ close(fd);
+ if (err)
+ break;
+ }
+
+ if (json_output)
+ jsonw_end_array(json_wtr); /* root array */
+
+exit_free:
+ delete_btf_table(&btf_prog_table);
+ delete_btf_table(&btf_map_table);
+
+ return err;
+}
+
static int do_help(int argc, char **argv)
{
if (json_output) {
@@ -530,7 +865,8 @@ static int do_help(int argc, char **argv)
}
fprintf(stderr,
- "Usage: %s btf dump BTF_SRC [format FORMAT]\n"
+ "Usage: %s btf { show | list } [id BTF_ID]\n"
+ " %s btf dump BTF_SRC [format FORMAT]\n"
" %s btf help\n"
"\n"
" BTF_SRC := { id BTF_ID | prog PROG | map MAP [{key | value | kv | all}] | file FILE }\n"
@@ -539,12 +875,14 @@ static int do_help(int argc, char **argv)
" " HELP_SPEC_PROGRAM "\n"
" " HELP_SPEC_OPTIONS "\n"
"",
- bin_name, bin_name);
+ bin_name, bin_name, bin_name);
return 0;
}
static const struct cmd cmds[] = {
+ { "show", do_show },
+ { "list", do_show },
{ "help", do_help },
{ "dump", do_dump },
{ 0 }
generated by cgit (git 2.34.1) at 2024-06-08 01:54:18 +0000