btf: expose API to work with raw btf_ext data
This patch changes struct btf_ext to retain original data in sequential block of memory, which makes it possible to expose btf_ext__get_raw_data() interface similar to btf__get_raw_data(), allowing users of libbpf to get access to raw representation of .BTF.ext section. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Andrii Nakryiko
Alexei Starovoitov
Родитель
02c874460f
Коммит
ae4ab4b411
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@ -42,9 +42,8 @@ struct btf {
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struct btf_ext_info {
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/*
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* info points to a deep copy of the individual info section
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* (e.g. func_info and line_info) from the .BTF.ext.
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* It does not include the __u32 rec_size.
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* info points to the individual info section (e.g. func_info and
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* line_info) from the .BTF.ext. It does not include the __u32 rec_size.
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*/
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void *info;
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__u32 rec_size;
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@ -52,8 +51,13 @@ struct btf_ext_info {
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};
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struct btf_ext {
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union {
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struct btf_ext_header *hdr;
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void *data;
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};
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struct btf_ext_info func_info;
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struct btf_ext_info line_info;
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__u32 data_size;
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};
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struct btf_ext_info_sec {
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@ -596,7 +600,7 @@ int btf__get_map_kv_tids(const struct btf *btf, const char *map_name,
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return 0;
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}
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struct btf_ext_sec_copy_param {
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struct btf_ext_sec_setup_param {
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__u32 off;
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__u32 len;
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__u32 min_rec_size;
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@ -604,20 +608,14 @@ struct btf_ext_sec_copy_param {
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const char *desc;
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};
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static int btf_ext_copy_info(struct btf_ext *btf_ext,
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__u8 *data, __u32 data_size,
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struct btf_ext_sec_copy_param *ext_sec)
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static int btf_ext_setup_info(struct btf_ext *btf_ext,
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struct btf_ext_sec_setup_param *ext_sec)
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{
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const struct btf_ext_header *hdr = (struct btf_ext_header *)data;
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const struct btf_ext_info_sec *sinfo;
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struct btf_ext_info *ext_info;
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__u32 info_left, record_size;
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/* The start of the info sec (including the __u32 record_size). */
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const void *info;
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/* data and data_size do not include btf_ext_header from now on */
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data = data + hdr->hdr_len;
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data_size -= hdr->hdr_len;
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void *info;
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if (ext_sec->off & 0x03) {
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pr_debug(".BTF.ext %s section is not aligned to 4 bytes\n",
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@ -625,16 +623,15 @@ static int btf_ext_copy_info(struct btf_ext *btf_ext,
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return -EINVAL;
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}
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if (data_size < ext_sec->off ||
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ext_sec->len > data_size - ext_sec->off) {
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info = btf_ext->data + btf_ext->hdr->hdr_len + ext_sec->off;
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info_left = ext_sec->len;
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if (btf_ext->data + btf_ext->data_size < info + ext_sec->len) {
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pr_debug("%s section (off:%u len:%u) is beyond the end of the ELF section .BTF.ext\n",
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ext_sec->desc, ext_sec->off, ext_sec->len);
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ext_sec->desc, ext_sec->off, ext_sec->len);
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return -EINVAL;
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}
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info = data + ext_sec->off;
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info_left = ext_sec->len;
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/* At least a record size */
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if (info_left < sizeof(__u32)) {
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pr_debug(".BTF.ext %s record size not found\n", ext_sec->desc);
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@ -646,7 +643,7 @@ static int btf_ext_copy_info(struct btf_ext *btf_ext,
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if (record_size < ext_sec->min_rec_size ||
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record_size & 0x03) {
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pr_debug("%s section in .BTF.ext has invalid record size %u\n",
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ext_sec->desc, record_size);
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ext_sec->desc, record_size);
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return -EINVAL;
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}
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@ -692,42 +689,35 @@ static int btf_ext_copy_info(struct btf_ext *btf_ext,
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ext_info = ext_sec->ext_info;
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ext_info->len = ext_sec->len - sizeof(__u32);
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ext_info->rec_size = record_size;
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ext_info->info = malloc(ext_info->len);
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if (!ext_info->info)
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return -ENOMEM;
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memcpy(ext_info->info, info + sizeof(__u32), ext_info->len);
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ext_info->info = info + sizeof(__u32);
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return 0;
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}
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static int btf_ext_copy_func_info(struct btf_ext *btf_ext,
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__u8 *data, __u32 data_size)
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static int btf_ext_setup_func_info(struct btf_ext *btf_ext)
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{
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const struct btf_ext_header *hdr = (struct btf_ext_header *)data;
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struct btf_ext_sec_copy_param param = {
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.off = hdr->func_info_off,
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.len = hdr->func_info_len,
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struct btf_ext_sec_setup_param param = {
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.off = btf_ext->hdr->func_info_off,
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.len = btf_ext->hdr->func_info_len,
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.min_rec_size = sizeof(struct bpf_func_info_min),
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.ext_info = &btf_ext->func_info,
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.desc = "func_info"
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};
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return btf_ext_copy_info(btf_ext, data, data_size, ¶m);
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return btf_ext_setup_info(btf_ext, ¶m);
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}
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static int btf_ext_copy_line_info(struct btf_ext *btf_ext,
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__u8 *data, __u32 data_size)
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static int btf_ext_setup_line_info(struct btf_ext *btf_ext)
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{
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const struct btf_ext_header *hdr = (struct btf_ext_header *)data;
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struct btf_ext_sec_copy_param param = {
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.off = hdr->line_info_off,
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.len = hdr->line_info_len,
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struct btf_ext_sec_setup_param param = {
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.off = btf_ext->hdr->line_info_off,
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.len = btf_ext->hdr->line_info_len,
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.min_rec_size = sizeof(struct bpf_line_info_min),
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.ext_info = &btf_ext->line_info,
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.desc = "line_info",
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};
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return btf_ext_copy_info(btf_ext, data, data_size, ¶m);
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return btf_ext_setup_info(btf_ext, ¶m);
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}
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static int btf_ext_parse_hdr(__u8 *data, __u32 data_size)
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@ -767,9 +757,7 @@ void btf_ext__free(struct btf_ext *btf_ext)
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{
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if (!btf_ext)
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return;
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free(btf_ext->func_info.info);
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free(btf_ext->line_info.info);
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free(btf_ext->data);
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free(btf_ext);
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}
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@ -786,13 +774,23 @@ struct btf_ext *btf_ext__new(__u8 *data, __u32 size)
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if (!btf_ext)
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return ERR_PTR(-ENOMEM);
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err = btf_ext_copy_func_info(btf_ext, data, size);
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if (err) {
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btf_ext__free(btf_ext);
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return ERR_PTR(err);
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btf_ext->data_size = size;
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btf_ext->data = malloc(size);
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if (!btf_ext->data) {
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err = -ENOMEM;
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goto done;
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}
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memcpy(btf_ext->data, data, size);
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err = btf_ext_copy_line_info(btf_ext, data, size);
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err = btf_ext_setup_func_info(btf_ext);
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if (err)
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goto done;
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err = btf_ext_setup_line_info(btf_ext);
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if (err)
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goto done;
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done:
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if (err) {
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btf_ext__free(btf_ext);
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return ERR_PTR(err);
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@ -801,6 +799,12 @@ struct btf_ext *btf_ext__new(__u8 *data, __u32 size)
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return btf_ext;
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}
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const void *btf_ext__get_raw_data(const struct btf_ext *btf_ext, __u32 *size)
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{
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*size = btf_ext->data_size;
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return btf_ext->data;
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}
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static int btf_ext_reloc_info(const struct btf *btf,
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const struct btf_ext_info *ext_info,
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const char *sec_name, __u32 insns_cnt,
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@ -849,7 +853,8 @@ static int btf_ext_reloc_info(const struct btf *btf,
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return -ENOENT;
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}
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int btf_ext__reloc_func_info(const struct btf *btf, const struct btf_ext *btf_ext,
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int btf_ext__reloc_func_info(const struct btf *btf,
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const struct btf_ext *btf_ext,
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const char *sec_name, __u32 insns_cnt,
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void **func_info, __u32 *cnt)
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{
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@ -857,7 +862,8 @@ int btf_ext__reloc_func_info(const struct btf *btf, const struct btf_ext *btf_ex
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insns_cnt, func_info, cnt);
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}
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int btf_ext__reloc_line_info(const struct btf *btf, const struct btf_ext *btf_ext,
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int btf_ext__reloc_line_info(const struct btf *btf,
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const struct btf_ext *btf_ext,
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const char *sec_name, __u32 insns_cnt,
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void **line_info, __u32 *cnt)
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{
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@ -78,6 +78,8 @@ LIBBPF_API int btf__get_map_kv_tids(const struct btf *btf, const char *map_name,
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LIBBPF_API struct btf_ext *btf_ext__new(__u8 *data, __u32 size);
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LIBBPF_API void btf_ext__free(struct btf_ext *btf_ext);
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LIBBPF_API const void *btf_ext__get_raw_data(const struct btf_ext* btf_ext,
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__u32 *size);
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LIBBPF_API int btf_ext__reloc_func_info(const struct btf *btf,
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const struct btf_ext *btf_ext,
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const char *sec_name, __u32 insns_cnt,
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@ -141,6 +141,7 @@ LIBBPF_0.0.2 {
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btf__load;
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btf_ext__free;
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btf_ext__func_info_rec_size;
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btf_ext__get_raw_data;
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btf_ext__line_info_rec_size;
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btf_ext__new;
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btf_ext__reloc_func_info;
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