0f12e584b2
Existing BTF_ID_LIST used a local static variable to store btf_ids. This patch provided a new macro BTF_ID_LIST_GLOBAL to store btf_ids in a global variable which can be shared among multiple files. The existing BTF_ID_LIST is still retained. Two reasons. First, BTF_ID_LIST is also used to build btf_ids for helper arguments which typically is an array of 5. Since typically different helpers have different signature, it makes little sense to share them. Second, some current computed btf_ids are indeed local. If later those btf_ids are shared between different files, they can use BTF_ID_LIST_GLOBAL then. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Jiri Olsa <jolsa@redhat.com> Link: https://lore.kernel.org/bpf/20200720163401.1393159-1-yhs@fb.com
129 lines
2.6 KiB
C
129 lines
2.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/err.h>
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#include <string.h>
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#include <bpf/btf.h>
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#include <bpf/libbpf.h>
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#include <linux/btf.h>
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#include <linux/kernel.h>
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#define CONFIG_DEBUG_INFO_BTF
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#include <linux/btf_ids.h>
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#include "test_progs.h"
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static int duration;
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struct symbol {
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const char *name;
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int type;
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int id;
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};
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struct symbol test_symbols[] = {
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{ "unused", BTF_KIND_UNKN, 0 },
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{ "S", BTF_KIND_TYPEDEF, -1 },
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{ "T", BTF_KIND_TYPEDEF, -1 },
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{ "U", BTF_KIND_TYPEDEF, -1 },
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{ "S", BTF_KIND_STRUCT, -1 },
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{ "U", BTF_KIND_UNION, -1 },
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{ "func", BTF_KIND_FUNC, -1 },
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};
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BTF_ID_LIST(test_list_local)
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BTF_ID_UNUSED
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BTF_ID(typedef, S)
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BTF_ID(typedef, T)
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BTF_ID(typedef, U)
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BTF_ID(struct, S)
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BTF_ID(union, U)
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BTF_ID(func, func)
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extern __u32 test_list_global[];
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BTF_ID_LIST_GLOBAL(test_list_global)
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BTF_ID_UNUSED
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BTF_ID(typedef, S)
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BTF_ID(typedef, T)
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BTF_ID(typedef, U)
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BTF_ID(struct, S)
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BTF_ID(union, U)
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BTF_ID(func, func)
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static int
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__resolve_symbol(struct btf *btf, int type_id)
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{
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const struct btf_type *type;
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const char *str;
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unsigned int i;
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type = btf__type_by_id(btf, type_id);
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if (!type) {
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PRINT_FAIL("Failed to get type for ID %d\n", type_id);
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return -1;
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}
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for (i = 0; i < ARRAY_SIZE(test_symbols); i++) {
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if (test_symbols[i].id != -1)
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continue;
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if (BTF_INFO_KIND(type->info) != test_symbols[i].type)
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continue;
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str = btf__name_by_offset(btf, type->name_off);
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if (!str) {
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PRINT_FAIL("Failed to get name for BTF ID %d\n", type_id);
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return -1;
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}
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if (!strcmp(str, test_symbols[i].name))
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test_symbols[i].id = type_id;
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}
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return 0;
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}
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static int resolve_symbols(void)
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{
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struct btf *btf;
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int type_id;
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__u32 nr;
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btf = btf__parse_elf("btf_data.o", NULL);
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if (CHECK(libbpf_get_error(btf), "resolve",
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"Failed to load BTF from btf_data.o\n"))
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return -1;
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nr = btf__get_nr_types(btf);
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for (type_id = 1; type_id <= nr; type_id++) {
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if (__resolve_symbol(btf, type_id))
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break;
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}
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btf__free(btf);
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return 0;
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}
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int test_resolve_btfids(void)
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{
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__u32 *test_list, *test_lists[] = { test_list_local, test_list_global };
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unsigned int i, j;
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int ret = 0;
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if (resolve_symbols())
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return -1;
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/* Check BTF_ID_LIST(test_list_local) and
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* BTF_ID_LIST_GLOBAL(test_list_global) IDs
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*/
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for (j = 0; j < ARRAY_SIZE(test_lists); j++) {
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test_list = test_lists[j];
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for (i = 0; i < ARRAY_SIZE(test_symbols) && !ret; i++) {
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ret = CHECK(test_list[i] != test_symbols[i].id,
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"id_check",
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"wrong ID for %s (%d != %d)\n",
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test_symbols[i].name,
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test_list[i], test_symbols[i].id);
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}
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}
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return ret;
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}
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