From 9c0f8cbdc0e9cf8a2a3a96045778b8d759f172c2 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Thu, 20 Aug 2020 16:12:39 -0700 Subject: [PATCH] libbpf: Normalize and improve logging across few functions Make libbpf logs follow similar pattern and provide more context like section name or program name, where appropriate. Also, add BPF_INSN_SZ constant and use it throughout to clean up code a little bit. This commit doesn't have any functional changes and just removes some code changes out of the way before bigger refactoring in libbpf internals. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200820231250.1293069-6-andriin@fb.com --- tools/lib/bpf/libbpf.c | 117 ++++++++++++++++++++++++++++--------------------- 1 file changed, 67 insertions(+), 50 deletions(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 2ae89b84a2be..fb7b8fb1d3fa 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -63,6 +63,8 @@ #define BPF_FS_MAGIC 0xcafe4a11 #endif +#define BPF_INSN_SZ (sizeof(struct bpf_insn)) + /* vsprintf() in __base_pr() uses nonliteral format string. It may break * compilation if user enables corresponding warning. Disable it explicitly. */ @@ -3225,7 +3227,7 @@ bpf_object__section_to_libbpf_map_type(const struct bpf_object *obj, int shndx) static int bpf_program__record_reloc(struct bpf_program *prog, struct reloc_desc *reloc_desc, - __u32 insn_idx, const char *name, + __u32 insn_idx, const char *sym_name, const GElf_Sym *sym, const GElf_Rel *rel) { struct bpf_insn *insn = &prog->insns[insn_idx]; @@ -3233,22 +3235,25 @@ static int bpf_program__record_reloc(struct bpf_program *prog, struct bpf_object *obj = prog->obj; __u32 shdr_idx = sym->st_shndx; enum libbpf_map_type type; + const char *sym_sec_name; struct bpf_map *map; /* sub-program call relocation */ if (insn->code == (BPF_JMP | BPF_CALL)) { if (insn->src_reg != BPF_PSEUDO_CALL) { - pr_warn("incorrect bpf_call opcode\n"); + pr_warn("prog '%s': incorrect bpf_call opcode\n", prog->name); return -LIBBPF_ERRNO__RELOC; } /* text_shndx can be 0, if no default "main" program exists */ if (!shdr_idx || shdr_idx != obj->efile.text_shndx) { - pr_warn("bad call relo against section %u\n", shdr_idx); + sym_sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, shdr_idx)); + pr_warn("prog '%s': bad call relo against '%s' in section '%s'\n", + prog->name, sym_name, sym_sec_name); return -LIBBPF_ERRNO__RELOC; } - if (sym->st_value % 8) { - pr_warn("bad call relo offset: %zu\n", - (size_t)sym->st_value); + if (sym->st_value % BPF_INSN_SZ) { + pr_warn("prog '%s': bad call relo against '%s' at offset %zu\n", + prog->name, sym_name, (size_t)sym->st_value); return -LIBBPF_ERRNO__RELOC; } reloc_desc->type = RELO_CALL; @@ -3259,8 +3264,8 @@ static int bpf_program__record_reloc(struct bpf_program *prog, } if (insn->code != (BPF_LD | BPF_IMM | BPF_DW)) { - pr_warn("invalid relo for insns[%d].code 0x%x\n", - insn_idx, insn->code); + pr_warn("prog '%s': invalid relo against '%s' for insns[%d].code 0x%x\n", + prog->name, sym_name, insn_idx, insn->code); return -LIBBPF_ERRNO__RELOC; } @@ -3275,12 +3280,12 @@ static int bpf_program__record_reloc(struct bpf_program *prog, break; } if (i >= n) { - pr_warn("extern relo failed to find extern for sym %d\n", - sym_idx); + pr_warn("prog '%s': extern relo failed to find extern for '%s' (%d)\n", + prog->name, sym_name, sym_idx); return -LIBBPF_ERRNO__RELOC; } - pr_debug("found extern #%d '%s' (sym %d) for insn %u\n", - i, ext->name, ext->sym_idx, insn_idx); + pr_debug("prog '%s': found extern #%d '%s' (sym %d) for insn #%u\n", + prog->name, i, ext->name, ext->sym_idx, insn_idx); reloc_desc->type = RELO_EXTERN; reloc_desc->insn_idx = insn_idx; reloc_desc->sym_off = i; /* sym_off stores extern index */ @@ -3288,18 +3293,19 @@ static int bpf_program__record_reloc(struct bpf_program *prog, } if (!shdr_idx || shdr_idx >= SHN_LORESERVE) { - pr_warn("invalid relo for \'%s\' in special section 0x%x; forgot to initialize global var?..\n", - name, shdr_idx); + pr_warn("prog '%s': invalid relo against '%s' in special section 0x%x; forgot to initialize global var?..\n", + prog->name, sym_name, shdr_idx); return -LIBBPF_ERRNO__RELOC; } type = bpf_object__section_to_libbpf_map_type(obj, shdr_idx); + sym_sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, shdr_idx)); /* generic map reference relocation */ if (type == LIBBPF_MAP_UNSPEC) { if (!bpf_object__shndx_is_maps(obj, shdr_idx)) { - pr_warn("bad map relo against section %u\n", - shdr_idx); + pr_warn("prog '%s': bad map relo against '%s' in section '%s'\n", + prog->name, sym_name, sym_sec_name); return -LIBBPF_ERRNO__RELOC; } for (map_idx = 0; map_idx < nr_maps; map_idx++) { @@ -3308,14 +3314,14 @@ static int bpf_program__record_reloc(struct bpf_program *prog, map->sec_idx != sym->st_shndx || map->sec_offset != sym->st_value) continue; - pr_debug("found map %zd (%s, sec %d, off %zu) for insn %u\n", - map_idx, map->name, map->sec_idx, + pr_debug("prog '%s': found map %zd (%s, sec %d, off %zu) for insn #%u\n", + prog->name, map_idx, map->name, map->sec_idx, map->sec_offset, insn_idx); break; } if (map_idx >= nr_maps) { - pr_warn("map relo failed to find map for sec %u, off %zu\n", - shdr_idx, (size_t)sym->st_value); + pr_warn("prog '%s': map relo failed to find map for section '%s', off %zu\n", + prog->name, sym_sec_name, (size_t)sym->st_value); return -LIBBPF_ERRNO__RELOC; } reloc_desc->type = RELO_LD64; @@ -3327,21 +3333,22 @@ static int bpf_program__record_reloc(struct bpf_program *prog, /* global data map relocation */ if (!bpf_object__shndx_is_data(obj, shdr_idx)) { - pr_warn("bad data relo against section %u\n", shdr_idx); + pr_warn("prog '%s': bad data relo against section '%s'\n", + prog->name, sym_sec_name); return -LIBBPF_ERRNO__RELOC; } for (map_idx = 0; map_idx < nr_maps; map_idx++) { map = &obj->maps[map_idx]; if (map->libbpf_type != type) continue; - pr_debug("found data map %zd (%s, sec %d, off %zu) for insn %u\n", - map_idx, map->name, map->sec_idx, map->sec_offset, - insn_idx); + pr_debug("prog '%s': found data map %zd (%s, sec %d, off %zu) for insn %u\n", + prog->name, map_idx, map->name, map->sec_idx, + map->sec_offset, insn_idx); break; } if (map_idx >= nr_maps) { - pr_warn("data relo failed to find map for sec %u\n", - shdr_idx); + pr_warn("prog '%s': data relo failed to find map for section '%s'\n", + prog->name, sym_sec_name); return -LIBBPF_ERRNO__RELOC; } @@ -3357,9 +3364,17 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr, Elf_Data *data, struct bpf_object *obj) { Elf_Data *symbols = obj->efile.symbols; + const char *relo_sec_name, *sec_name; + size_t sec_idx = shdr->sh_info; int err, i, nrels; - pr_debug("collecting relocating info for: '%s'\n", prog->section_name); + relo_sec_name = elf_sec_str(obj, shdr->sh_name); + sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, sec_idx)); + if (!relo_sec_name || !sec_name) + return -EINVAL; + + pr_debug("sec '%s': collecting relocation for section(%zu) '%s'\n", + relo_sec_name, sec_idx, sec_name); nrels = shdr->sh_size / shdr->sh_entsize; prog->reloc_desc = malloc(sizeof(*prog->reloc_desc) * nrels); @@ -3370,34 +3385,34 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr, prog->nr_reloc = nrels; for (i = 0; i < nrels; i++) { - const char *name; + const char *sym_name; __u32 insn_idx; GElf_Sym sym; GElf_Rel rel; if (!gelf_getrel(data, i, &rel)) { - pr_warn("relocation: failed to get %d reloc\n", i); + pr_warn("sec '%s': failed to get relo #%d\n", relo_sec_name, i); return -LIBBPF_ERRNO__FORMAT; } if (!gelf_getsym(symbols, GELF_R_SYM(rel.r_info), &sym)) { - pr_warn("relocation: symbol %zx not found\n", - (size_t)GELF_R_SYM(rel.r_info)); + pr_warn("sec '%s': symbol 0x%zx not found for relo #%d\n", + relo_sec_name, (size_t)GELF_R_SYM(rel.r_info), i); return -LIBBPF_ERRNO__FORMAT; } - if (rel.r_offset % sizeof(struct bpf_insn)) + if (rel.r_offset % BPF_INSN_SZ) { + pr_warn("sec '%s': invalid offset 0x%zx for relo #%d\n", + relo_sec_name, (size_t)GELF_R_SYM(rel.r_info), i); return -LIBBPF_ERRNO__FORMAT; + } - insn_idx = rel.r_offset / sizeof(struct bpf_insn); - name = elf_sym_str(obj, sym.st_name) ?: ""; + insn_idx = rel.r_offset / BPF_INSN_SZ; + sym_name = elf_sym_str(obj, sym.st_name) ?: ""; - pr_debug("relo for shdr %u, symb %zu, value %zu, type %d, bind %d, name %d (\'%s\'), insn %u\n", - (__u32)sym.st_shndx, (size_t)GELF_R_SYM(rel.r_info), - (size_t)sym.st_value, GELF_ST_TYPE(sym.st_info), - GELF_ST_BIND(sym.st_info), sym.st_name, name, - insn_idx); + pr_debug("sec '%s': relo #%d: insn #%u against '%s'\n", + relo_sec_name, i, insn_idx, sym_name); err = bpf_program__record_reloc(prog, &prog->reloc_desc[i], - insn_idx, name, &sym, &rel); + insn_idx, sym_name, &sym, &rel); if (err) return err; } @@ -5155,9 +5170,9 @@ static int bpf_core_patch_insn(struct bpf_program *prog, int insn_idx; __u8 class; - if (relo->insn_off % sizeof(struct bpf_insn)) + if (relo->insn_off % BPF_INSN_SZ) return -EINVAL; - insn_idx = relo->insn_off / sizeof(struct bpf_insn); + insn_idx = relo->insn_off / BPF_INSN_SZ; insn = &prog->insns[insn_idx]; class = BPF_CLASS(insn->code); @@ -5588,7 +5603,7 @@ bpf_object__relocate_core(struct bpf_object *obj, const char *targ_btf_path) goto out; } - pr_debug("prog '%s': performing %d CO-RE offset relocs\n", + pr_debug("sec '%s': found %d CO-RE relocations\n", sec_name, sec->num_info); for_each_btf_ext_rec(seg, sec, i, rec) { @@ -5596,7 +5611,7 @@ bpf_object__relocate_core(struct bpf_object *obj, const char *targ_btf_path) targ_btf, cand_cache); if (err) { pr_warn("prog '%s': relo #%d: failed to relocate: %d\n", - sec_name, i, err); + prog->name, i, err); goto out; } } @@ -5716,7 +5731,8 @@ bpf_program__relocate(struct bpf_program *prog, struct bpf_object *obj) return err; break; default: - pr_warn("relo #%d: bad relo type %d\n", i, relo->type); + pr_warn("prog '%s': relo #%d: bad relo type %d\n", + prog->name, i, relo->type); return -EINVAL; } } @@ -5751,7 +5767,8 @@ bpf_object__relocate(struct bpf_object *obj, const char *targ_btf_path) err = bpf_program__relocate(prog, obj); if (err) { - pr_warn("failed to relocate '%s'\n", prog->section_name); + pr_warn("prog '%s': failed to relocate data references: %d\n", + prog->name, err); return err; } break; @@ -5766,7 +5783,8 @@ bpf_object__relocate(struct bpf_object *obj, const char *targ_btf_path) err = bpf_program__relocate(prog, obj); if (err) { - pr_warn("failed to relocate '%s'\n", prog->section_name); + pr_warn("prog '%s': failed to relocate calls: %d\n", + prog->name, err); return err; } } @@ -6198,8 +6216,7 @@ bpf_object__load_progs(struct bpf_object *obj, int log_level) if (bpf_program__is_function_storage(prog, obj)) continue; if (!prog->load) { - pr_debug("prog '%s'('%s'): skipped loading\n", - prog->name, prog->section_name); + pr_debug("prog '%s': skipped loading\n", prog->name); continue; } prog->log_level |= log_level; @@ -7343,7 +7360,7 @@ int bpf_program__fd(const struct bpf_program *prog) size_t bpf_program__size(const struct bpf_program *prog) { - return prog->insns_cnt * sizeof(struct bpf_insn); + return prog->insns_cnt * BPF_INSN_SZ; } int bpf_program__set_prep(struct bpf_program *prog, int nr_instances, -- 2.11.0