diff --git a/usr.sbin/kldxref/ef.c b/usr.sbin/kldxref/ef.c index aa9123d7f540..46d3dc1f4578 100644 --- a/usr.sbin/kldxref/ef.c +++ b/usr.sbin/kldxref/ef.c @@ -1,650 +1,650 @@ /*- * SPDX-License-Identifier: BSD-4-Clause * * Copyright (c) 2000, Boris Popov * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by Boris Popov. * 4. Neither the name of the author nor the names of any co-contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #include #include #include #include #include #include #include "ef.h" #define MAXSEGS 16 struct ef_file { char *ef_name; struct elf_file *ef_efile; GElf_Phdr *ef_ph; void *ef_fpage; /* First block of the file */ int ef_fplen; /* length of first block */ GElf_Hashelt ef_nbuckets; GElf_Hashelt ef_nchains; GElf_Hashelt *ef_buckets; GElf_Hashelt *ef_chains; GElf_Hashelt *ef_hashtab; caddr_t ef_strtab; long ef_strsz; GElf_Sym *ef_symtab; int ef_nsegs; GElf_Phdr *ef_segs[MAXSEGS]; int ef_verbose; GElf_Rel *ef_rel; /* relocation table */ long ef_relsz; /* number of entries */ GElf_Rela *ef_rela; /* relocation table */ long ef_relasz; /* number of entries */ }; static void ef_print_phdr(GElf_Phdr *); static GElf_Off ef_get_offset(elf_file_t, GElf_Addr); static void ef_close(elf_file_t ef); static int ef_seg_read_rel(elf_file_t ef, GElf_Addr address, size_t len, void *dest); static int ef_seg_read_string(elf_file_t ef, GElf_Addr address, size_t len, char *dest); static GElf_Addr ef_symaddr(elf_file_t ef, GElf_Size symidx); static int ef_lookup_set(elf_file_t ef, const char *name, GElf_Addr *startp, GElf_Addr *stopp, long *countp); static int ef_lookup_symbol(elf_file_t ef, const char *name, GElf_Sym **sym); static struct elf_file_ops ef_file_ops = { .close = ef_close, .seg_read_rel = ef_seg_read_rel, .seg_read_string = ef_seg_read_string, .symaddr = ef_symaddr, .lookup_set = ef_lookup_set, }; static void ef_print_phdr(GElf_Phdr *phdr) { if ((phdr->p_flags & PF_W) == 0) { printf("text=0x%jx ", (uintmax_t)phdr->p_filesz); } else { printf("data=0x%jx", (uintmax_t)phdr->p_filesz); if (phdr->p_filesz < phdr->p_memsz) printf("+0x%jx", (uintmax_t)(phdr->p_memsz - phdr->p_filesz)); printf(" "); } } static GElf_Off ef_get_offset(elf_file_t ef, GElf_Addr addr) { GElf_Phdr *ph; int i; for (i = 0; i < ef->ef_nsegs; i++) { ph = ef->ef_segs[i]; if (addr >= ph->p_vaddr && addr < ph->p_vaddr + ph->p_memsz) { return (ph->p_offset + (addr - ph->p_vaddr)); } } return (0); } /* * next two functions copied from link_elf.c */ static int ef_lookup_symbol(elf_file_t ef, const char *name, GElf_Sym **sym) { unsigned long hash, symnum; GElf_Sym *symp; char *strp; /* First, search hashed global symbols */ hash = elf_hash(name); symnum = ef->ef_buckets[hash % ef->ef_nbuckets]; while (symnum != STN_UNDEF) { if (symnum >= ef->ef_nchains) { warnx("ef_lookup_symbol: file %s have corrupted symbol table\n", ef->ef_name); return (ENOENT); } symp = ef->ef_symtab + symnum; if (symp->st_name == 0) { warnx("ef_lookup_symbol: file %s have corrupted symbol table\n", ef->ef_name); return (ENOENT); } strp = ef->ef_strtab + symp->st_name; if (strcmp(name, strp) == 0) { if (symp->st_shndx != SHN_UNDEF || (symp->st_value != 0 && GELF_ST_TYPE(symp->st_info) == STT_FUNC)) { *sym = symp; return (0); } else return (ENOENT); } symnum = ef->ef_chains[symnum]; } return (ENOENT); } static int ef_lookup_set(elf_file_t ef, const char *name, GElf_Addr *startp, GElf_Addr *stopp, long *countp) { GElf_Sym *sym; char *setsym; int error, len; len = strlen(name) + sizeof("__start_set_"); /* sizeof includes \0 */ setsym = malloc(len); if (setsym == NULL) return (errno); /* get address of first entry */ snprintf(setsym, len, "%s%s", "__start_set_", name); error = ef_lookup_symbol(ef, setsym, &sym); if (error != 0) goto out; *startp = sym->st_value; /* get address of last entry */ snprintf(setsym, len, "%s%s", "__stop_set_", name); error = ef_lookup_symbol(ef, setsym, &sym); if (error != 0) goto out; *stopp = sym->st_value; /* and the number of entries */ *countp = (*stopp - *startp) / elf_pointer_size(ef->ef_efile); out: free(setsym); return (error); } static GElf_Addr ef_symaddr(elf_file_t ef, GElf_Size symidx) { const GElf_Sym *sym; if (symidx >= ef->ef_nchains) return (0); sym = ef->ef_symtab + symidx; if (GELF_ST_BIND(sym->st_info) == STB_LOCAL && sym->st_shndx != SHN_UNDEF && sym->st_value != 0) return (sym->st_value); return (0); } static int ef_parse_dynamic(elf_file_t ef, const GElf_Phdr *phdyn) { GElf_Shdr *shdr; GElf_Dyn *dyn, *dp; size_t i, ndyn, nshdr, nsym; int error; GElf_Off hash_off, sym_off, str_off; GElf_Off rel_off; GElf_Off rela_off; int rel_sz; int rela_sz; int dynamic_idx; /* * The kernel linker parses the PT_DYNAMIC segment to find * various important tables. The gelf API of libelf is * section-oriented and requires extracting data from sections * instead of segments (program headers). As a result, * iterate over section headers to read various tables after * parsing values from PT_DYNAMIC. */ error = elf_read_shdrs(ef->ef_efile, &nshdr, &shdr); if (error != 0) return (EFTYPE); dyn = NULL; /* Find section for .dynamic. */ dynamic_idx = -1; for (i = 0; i < nshdr; i++) { if (shdr[i].sh_type == SHT_DYNAMIC) { if (shdr[i].sh_offset != phdyn->p_offset || shdr[i].sh_size != phdyn->p_filesz) { warnx(".dynamic section doesn't match phdr"); error = EFTYPE; goto out; } if (dynamic_idx != -1) { warnx("multiple SHT_DYNAMIC sections"); error = EFTYPE; goto out; } dynamic_idx = i; } } error = elf_read_dynamic(ef->ef_efile, dynamic_idx, &ndyn, &dyn); if (error != 0) goto out; hash_off = rel_off = rela_off = sym_off = str_off = 0; rel_sz = rela_sz = 0; for (i = 0; i < ndyn; i++) { dp = &dyn[i]; if (dp->d_tag == DT_NULL) break; switch (dp->d_tag) { case DT_HASH: if (hash_off != 0) warnx("second DT_HASH entry ignored"); else hash_off = ef_get_offset(ef, dp->d_un.d_ptr); break; case DT_STRTAB: if (str_off != 0) warnx("second DT_STRTAB entry ignored"); else str_off = ef_get_offset(ef, dp->d_un.d_ptr); break; case DT_SYMTAB: if (sym_off != 0) warnx("second DT_SYMTAB entry ignored"); else sym_off = ef_get_offset(ef, dp->d_un.d_ptr); break; case DT_SYMENT: if (dp->d_un.d_val != elf_object_size(ef->ef_efile, ELF_T_SYM)) { error = EFTYPE; goto out; } break; case DT_REL: if (rel_off != 0) warnx("second DT_REL entry ignored"); else rel_off = ef_get_offset(ef, dp->d_un.d_ptr); break; case DT_RELSZ: if (rel_sz != 0) warnx("second DT_RELSZ entry ignored"); else rel_sz = dp->d_un.d_val; break; case DT_RELENT: if (dp->d_un.d_val != elf_object_size(ef->ef_efile, ELF_T_REL)) { error = EFTYPE; goto out; } break; case DT_RELA: if (rela_off != 0) warnx("second DT_RELA entry ignored"); else rela_off = ef_get_offset(ef, dp->d_un.d_ptr); break; case DT_RELASZ: if (rela_sz != 0) warnx("second DT_RELSZ entry ignored"); else rela_sz = dp->d_un.d_val; break; case DT_RELAENT: if (dp->d_un.d_val != elf_object_size(ef->ef_efile, ELF_T_RELA)) { error = EFTYPE; goto out; } break; } } if (hash_off == 0) { warnx("%s: no .hash section found\n", ef->ef_name); error = EFTYPE; goto out; } if (sym_off == 0) { warnx("%s: no .dynsym section found\n", ef->ef_name); error = EFTYPE; goto out; } if (str_off == 0) { warnx("%s: no .dynstr section found\n", ef->ef_name); error = EFTYPE; goto out; } if (rel_off == 0 && rela_off == 0) { warnx("%s: no ELF relocation table found\n", ef->ef_name); error = EFTYPE; goto out; } for (i = 0; i < nshdr; i++) { switch (shdr[i].sh_type) { case SHT_HASH: if (shdr[i].sh_offset != hash_off) { warnx("%s: ignoring SHT_HASH at different offset from DT_HASH", ef->ef_name); break; } /* * libelf(3) mentions ELF_T_HASH, but it is * not defined. */ if (shdr[i].sh_size < sizeof(*ef->ef_hashtab) * 2) { warnx("hash section too small"); error = EFTYPE; goto out; } error = elf_read_data(ef->ef_efile, ELF_T_WORD, shdr[i].sh_offset, shdr[i].sh_size, (void **)&ef->ef_hashtab); if (error != 0) { warnc(error, "can't read hash table"); goto out; } ef->ef_nbuckets = ef->ef_hashtab[0]; ef->ef_nchains = ef->ef_hashtab[1]; if ((2 + ef->ef_nbuckets + ef->ef_nchains) * sizeof(*ef->ef_hashtab) != shdr[i].sh_size) { warnx("inconsistent hash section size"); error = EFTYPE; goto out; } ef->ef_buckets = ef->ef_hashtab + 2; ef->ef_chains = ef->ef_buckets + ef->ef_nbuckets; break; case SHT_DYNSYM: if (shdr[i].sh_offset != sym_off) { warnx("%s: ignoring SHT_DYNSYM at different offset from DT_SYMTAB", ef->ef_name); break; } error = elf_read_symbols(ef->ef_efile, i, &nsym, &ef->ef_symtab); if (error != 0) { if (ef->ef_verbose) warnx("%s: can't load .dynsym section (0x%jx)", ef->ef_name, (uintmax_t)sym_off); goto out; } break; case SHT_STRTAB: if (shdr[i].sh_offset != str_off) break; error = elf_read_string_table(ef->ef_efile, &shdr[i], &ef->ef_strsz, &ef->ef_strtab); if (error != 0) { warnx("can't load .dynstr section"); error = EIO; goto out; } break; case SHT_REL: if (shdr[i].sh_offset != rel_off) break; if (shdr[i].sh_size != rel_sz) { warnx("%s: size mismatch for DT_REL section", ef->ef_name); error = EFTYPE; goto out; } error = elf_read_rel(ef->ef_efile, i, &ef->ef_relsz, &ef->ef_rel); if (error != 0) { warnx("%s: cannot load DT_REL section", ef->ef_name); goto out; } break; case SHT_RELA: if (shdr[i].sh_offset != rela_off) break; if (shdr[i].sh_size != rela_sz) { warnx("%s: size mismatch for DT_RELA section", ef->ef_name); error = EFTYPE; goto out; } error = elf_read_rela(ef->ef_efile, i, &ef->ef_relasz, &ef->ef_rela); if (error != 0) { warnx("%s: cannot load DT_RELA section", ef->ef_name); goto out; } break; } } if (ef->ef_hashtab == NULL) { warnx("%s: did not find a symbol hash table", ef->ef_name); error = EFTYPE; goto out; } if (ef->ef_symtab == NULL) { warnx("%s: did not find a dynamic symbol table", ef->ef_name); error = EFTYPE; goto out; } if (nsym != ef->ef_nchains) { warnx("%s: symbol count mismatch", ef->ef_name); error = EFTYPE; goto out; } if (ef->ef_strtab == NULL) { warnx("%s: did not find a dynamic string table", ef->ef_name); error = EFTYPE; goto out; } if (rel_off != 0 && ef->ef_rel == NULL) { warnx("%s: did not find a DT_REL relocation table", ef->ef_name); error = EFTYPE; goto out; } if (rela_off != 0 && ef->ef_rela == NULL) { warnx("%s: did not find a DT_RELA relocation table", ef->ef_name); error = EFTYPE; goto out; } error = 0; out: free(dyn); free(shdr); return (error); } static int ef_seg_read_rel(elf_file_t ef, GElf_Addr address, size_t len, void *dest) { GElf_Off ofs; const GElf_Rela *a; const GElf_Rel *r; int error; ofs = ef_get_offset(ef, address); if (ofs == 0) { if (ef->ef_verbose) - warnx("ef_seg_read_rel(%s): zero offset (%jx:%ju)", - ef->ef_name, (uintmax_t)address, (uintmax_t)ofs); + warnx("ef_seg_read_rel(%s): bad address (%jx)", + ef->ef_name, (uintmax_t)address); return (EFAULT); } error = elf_read_raw_data(ef->ef_efile, ofs, dest, len); if (error != 0) return (error); for (r = ef->ef_rel; r < &ef->ef_rel[ef->ef_relsz]; r++) { error = elf_reloc(ef->ef_efile, r, ELF_T_REL, 0, address, len, dest); if (error != 0) return (error); } for (a = ef->ef_rela; a < &ef->ef_rela[ef->ef_relasz]; a++) { error = elf_reloc(ef->ef_efile, a, ELF_T_RELA, 0, address, len, dest); if (error != 0) return (error); } return (0); } static int ef_seg_read_string(elf_file_t ef, GElf_Addr address, size_t len, char *dest) { GElf_Off ofs; int error; ofs = ef_get_offset(ef, address); - if (ofs == 0 || ofs == (GElf_Off)-1) { + if (ofs == 0) { if (ef->ef_verbose) warnx("ef_seg_read_string(%s): bad offset (%jx:%ju)", ef->ef_name, (uintmax_t)address, (uintmax_t)ofs); return (EFAULT); } error = elf_read_raw_data(ef->ef_efile, ofs, dest, len); if (error != 0) return (error); if (strnlen(dest, len) == len) return (EFAULT); return (0); } int ef_open(struct elf_file *efile, int verbose) { elf_file_t ef; GElf_Ehdr *hdr; size_t i, nphdr, nsegs; int error; GElf_Phdr *phdr, *phdyn; hdr = &efile->ef_hdr; if (hdr->e_phnum == 0 || hdr->e_phentsize != elf_object_size(efile, ELF_T_PHDR) || hdr->e_shnum == 0 || hdr->e_shoff == 0 || hdr->e_shentsize != elf_object_size(efile, ELF_T_SHDR)) return (EFTYPE); ef = malloc(sizeof(*ef)); if (ef == NULL) return (errno); efile->ef_ef = ef; efile->ef_ops = &ef_file_ops; bzero(ef, sizeof(*ef)); ef->ef_verbose = verbose; ef->ef_name = strdup(efile->ef_filename); ef->ef_efile = efile; error = elf_read_phdrs(efile, &nphdr, &ef->ef_ph); if (error != 0) { phdr = NULL; goto out; } error = EFTYPE; nsegs = 0; phdyn = NULL; phdr = ef->ef_ph; for (i = 0; i < nphdr; i++, phdr++) { if (verbose > 1) ef_print_phdr(phdr); switch (phdr->p_type) { case PT_LOAD: if (nsegs < MAXSEGS) ef->ef_segs[nsegs] = phdr; nsegs++; break; case PT_PHDR: break; case PT_DYNAMIC: phdyn = phdr; break; } } if (verbose > 1) printf("\n"); if (phdyn == NULL) { warnx("Skipping %s: not dynamically-linked", ef->ef_name); goto out; } if (nsegs > MAXSEGS) { warnx("%s: too many segments", ef->ef_name); goto out; } ef->ef_nsegs = nsegs; error = ef_parse_dynamic(ef, phdyn); out: if (error != 0) ef_close(ef); return (error); } static void ef_close(elf_file_t ef) { free(ef->ef_rela); free(ef->ef_rel); free(ef->ef_strtab); free(ef->ef_symtab); free(ef->ef_hashtab); free(ef->ef_ph); if (ef->ef_name) free(ef->ef_name); ef->ef_efile->ef_ops = NULL; ef->ef_efile->ef_ef = NULL; free(ef); }