diff options
Diffstat (limited to 'tools/bpf/bpftool/btf.c')
| -rw-r--r-- | tools/bpf/bpftool/btf.c | 162 |
1 files changed, 66 insertions, 96 deletions
diff --git a/tools/bpf/bpftool/btf.c b/tools/bpf/bpftool/btf.c index 7317438ecd9e..1b8ec91899e6 100644 --- a/tools/bpf/bpftool/btf.c +++ b/tools/bpf/bpftool/btf.c @@ -8,8 +8,8 @@ #include <stdio.h> #include <string.h> #include <unistd.h> -#include <gelf.h> #include <bpf.h> +#include <libbpf.h> #include <linux/btf.h> #include "btf.h" @@ -340,109 +340,40 @@ static int dump_btf_raw(const struct btf *btf, return 0; } -static bool check_btf_endianness(GElf_Ehdr *ehdr) +static void __printf(2, 0) btf_dump_printf(void *ctx, + const char *fmt, va_list args) { - static unsigned int const endian = 1; - - switch (ehdr->e_ident[EI_DATA]) { - case ELFDATA2LSB: - return *(unsigned char const *)&endian == 1; - case ELFDATA2MSB: - return *(unsigned char const *)&endian == 0; - default: - return 0; - } + vfprintf(stdout, fmt, args); } -static int btf_load_from_elf(const char *path, struct btf **btf) +static int dump_btf_c(const struct btf *btf, + __u32 *root_type_ids, int root_type_cnt) { - int err = -1, fd = -1, idx = 0; - Elf_Data *btf_data = NULL; - Elf_Scn *scn = NULL; - Elf *elf = NULL; - GElf_Ehdr ehdr; - - if (elf_version(EV_CURRENT) == EV_NONE) { - p_err("failed to init libelf for %s", path); - return -1; - } - - fd = open(path, O_RDONLY); - if (fd < 0) { - p_err("failed to open %s: %s", path, strerror(errno)); - return -1; - } - - elf = elf_begin(fd, ELF_C_READ, NULL); - if (!elf) { - p_err("failed to open %s as ELF file", path); - goto done; - } - if (!gelf_getehdr(elf, &ehdr)) { - p_err("failed to get EHDR from %s", path); - goto done; - } - if (!check_btf_endianness(&ehdr)) { - p_err("non-native ELF endianness is not supported"); - goto done; - } - if (!elf_rawdata(elf_getscn(elf, ehdr.e_shstrndx), NULL)) { - p_err("failed to get e_shstrndx from %s\n", path); - goto done; - } + struct btf_dump *d; + int err = 0, i; - while ((scn = elf_nextscn(elf, scn)) != NULL) { - GElf_Shdr sh; - char *name; + d = btf_dump__new(btf, NULL, NULL, btf_dump_printf); + if (IS_ERR(d)) + return PTR_ERR(d); - idx++; - if (gelf_getshdr(scn, &sh) != &sh) { - p_err("failed to get section(%d) header from %s", - idx, path); - goto done; - } - name = elf_strptr(elf, ehdr.e_shstrndx, sh.sh_name); - if (!name) { - p_err("failed to get section(%d) name from %s", - idx, path); - goto done; - } - if (strcmp(name, BTF_ELF_SEC) == 0) { - btf_data = elf_getdata(scn, 0); - if (!btf_data) { - p_err("failed to get section(%d, %s) data from %s", - idx, name, path); + if (root_type_cnt) { + for (i = 0; i < root_type_cnt; i++) { + err = btf_dump__dump_type(d, root_type_ids[i]); + if (err) goto done; - } - break; } - } - - if (!btf_data) { - p_err("%s ELF section not found in %s", BTF_ELF_SEC, path); - goto done; - } + } else { + int cnt = btf__get_nr_types(btf); - *btf = btf__new(btf_data->d_buf, btf_data->d_size); - if (IS_ERR(*btf)) { - err = PTR_ERR(*btf); - *btf = NULL; - p_err("failed to load BTF data from %s: %s", - path, strerror(err)); - goto done; + for (i = 1; i <= cnt; i++) { + err = btf_dump__dump_type(d, i); + if (err) + goto done; + } } - err = 0; done: - if (err) { - if (*btf) { - btf__free(*btf); - *btf = NULL; - } - } - if (elf) - elf_end(elf); - close(fd); + btf_dump__free(d); return err; } @@ -451,6 +382,7 @@ static int do_dump(int argc, char **argv) struct btf *btf = NULL; __u32 root_type_ids[2]; int root_type_cnt = 0; + bool dump_c = false; __u32 btf_id = -1; const char *src; int fd = -1; @@ -522,9 +454,14 @@ static int do_dump(int argc, char **argv) } NEXT_ARG(); } else if (is_prefix(src, "file")) { - err = btf_load_from_elf(*argv, &btf); - if (err) + btf = btf__parse_elf(*argv, NULL); + if (IS_ERR(btf)) { + err = PTR_ERR(btf); + btf = NULL; + p_err("failed to load BTF from %s: %s", + *argv, strerror(err)); goto done; + } NEXT_ARG(); } else { err = -1; @@ -532,6 +469,29 @@ static int do_dump(int argc, char **argv) goto done; } + while (argc) { + if (is_prefix(*argv, "format")) { + NEXT_ARG(); + if (argc < 1) { + p_err("expecting value for 'format' option\n"); + goto done; + } + if (strcmp(*argv, "c") == 0) { + dump_c = true; + } else if (strcmp(*argv, "raw") == 0) { + dump_c = false; + } else { + p_err("unrecognized format specifier: '%s', possible values: raw, c", + *argv); + goto done; + } + NEXT_ARG(); + } else { + p_err("unrecognized option: '%s'", *argv); + goto done; + } + } + if (!btf) { err = btf__get_from_id(btf_id, &btf); if (err) { @@ -545,7 +505,16 @@ static int do_dump(int argc, char **argv) } } - dump_btf_raw(btf, root_type_ids, root_type_cnt); + if (dump_c) { + if (json_output) { + p_err("JSON output for C-syntax dump is not supported"); + err = -ENOTSUP; + goto done; + } + err = dump_btf_c(btf, root_type_ids, root_type_cnt); + } else { + err = dump_btf_raw(btf, root_type_ids, root_type_cnt); + } done: close(fd); @@ -561,10 +530,11 @@ static int do_help(int argc, char **argv) } fprintf(stderr, - "Usage: %s btf dump BTF_SRC\n" + "Usage: %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" + " FORMAT := { raw | c }\n" " " HELP_SPEC_MAP "\n" " " HELP_SPEC_PROGRAM "\n" " " HELP_SPEC_OPTIONS "\n" |