From c3e1384b735893fb696decada171b5a37473ba2c Mon Sep 17 00:00:00 2001 From: iedowse Date: Fri, 27 Aug 2004 00:58:40 +0000 Subject: Add support for reading ELF relocatable object file format modules. --- usr.sbin/kldxref/Makefile | 2 +- usr.sbin/kldxref/ef_obj.c | 602 +++++++++++++++++++++++++++++++++++++++++++++ usr.sbin/kldxref/kldxref.c | 9 +- 3 files changed, 609 insertions(+), 4 deletions(-) create mode 100644 usr.sbin/kldxref/ef_obj.c (limited to 'usr.sbin/kldxref') diff --git a/usr.sbin/kldxref/Makefile b/usr.sbin/kldxref/Makefile index c270085..33337fd 100644 --- a/usr.sbin/kldxref/Makefile +++ b/usr.sbin/kldxref/Makefile @@ -2,7 +2,7 @@ PROG= kldxref MAN= kldxref.8 -SRCS= kldxref.c ef.c +SRCS= kldxref.c ef.c ef_obj.c WARNS?= 2 diff --git a/usr.sbin/kldxref/ef_obj.c b/usr.sbin/kldxref/ef_obj.c new file mode 100644 index 0000000..0406f6a --- /dev/null +++ b/usr.sbin/kldxref/ef_obj.c @@ -0,0 +1,602 @@ +/* + * Copyright (c) 2000, Boris Popov + * Copyright (c) 1998-2000 Doug Rabson + * Copyright (c) 2004 Peter Wemm + * 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. + * + * $FreeBSD$ + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#define FREEBSD_ELF +#include + +#include + +#include "ef.h" + +typedef struct { + void *addr; + Elf_Off size; + int flags; + int sec; /* Original section */ + char *name; +} Elf_progent; + +typedef struct { + Elf_Rel *rel; + int nrel; + int sec; +} Elf_relent; + +typedef struct { + Elf_Rela *rela; + int nrela; + int sec; +} Elf_relaent; + +struct ef_file { + char *ef_name; + int ef_fd; + Elf_Ehdr ef_hdr; + struct elf_file *ef_efile; + + caddr_t address; + Elf_Off size; + Elf_Shdr *e_shdr; + + Elf_progent *progtab; + int nprogtab; + + Elf_relaent *relatab; + int nrela; + + Elf_relent *reltab; + int nrel; + + Elf_Sym *ddbsymtab; /* The symbol table we are using */ + long ddbsymcnt; /* Number of symbols */ + caddr_t ddbstrtab; /* String table */ + long ddbstrcnt; /* number of bytes in string table */ + + caddr_t shstrtab; /* Section name string table */ + long shstrcnt; /* number of bytes in string table */ + + int ef_verbose; +}; + +static int ef_obj_get_type(elf_file_t ef); +static int ef_obj_close(elf_file_t ef); +static int ef_obj_read(elf_file_t ef, Elf_Off offset, size_t len, void* dest); +static int ef_obj_read_entry(elf_file_t ef, Elf_Off offset, size_t len, + void **ptr); +static int ef_obj_seg_read(elf_file_t ef, Elf_Off offset, size_t len, + void *dest); +static int ef_obj_seg_read_rel(elf_file_t ef, Elf_Off offset, size_t len, + void *dest); +static int ef_obj_seg_read_entry(elf_file_t ef, Elf_Off offset, size_t len, + void **ptr); +static int ef_obj_seg_read_entry_rel(elf_file_t ef, Elf_Off offset, size_t len, + void **ptr); +static Elf_Addr ef_obj_symaddr(elf_file_t ef, Elf_Word symidx); +static int ef_obj_lookup_set(elf_file_t ef, const char *name, long *startp, + long *stopp, long *countp); +static int ef_obj_lookup_symbol(elf_file_t ef, const char* name, Elf_Sym** sym); + +static struct elf_file_ops ef_obj_file_ops = { + ef_obj_get_type, + ef_obj_close, + ef_obj_read, + ef_obj_read_entry, + ef_obj_seg_read, + ef_obj_seg_read_rel, + ef_obj_seg_read_entry, + ef_obj_seg_read_entry_rel, + ef_obj_symaddr, + ef_obj_lookup_set, + ef_obj_lookup_symbol +}; + +static int +ef_obj_get_type(elf_file_t ef) +{ + + return (EFT_KLD); +} + +static int +ef_obj_lookup_symbol(elf_file_t ef, const char* name, Elf_Sym** sym) +{ + Elf_Sym *symp; + const char *strp; + int i; + + for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { + strp = ef->ddbstrtab + symp->st_name; + if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) { + *sym = symp; + return 0; + } + } + return ENOENT; +} + +static int +ef_obj_lookup_set(elf_file_t ef, const char *name, long *startp, long *stopp, + long *countp) +{ + int i; + + for (i = 0; i < ef->nprogtab; i++) { + if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) && + strcmp(ef->progtab[i].name + 4, name) == 0) { + *startp = (char *)ef->progtab[i].addr - ef->address; + *stopp = (char *)ef->progtab[i].addr + + ef->progtab[i].size - ef->address; + *countp = (*stopp - *startp) / sizeof(void *); + return (0); + } + } + return (ESRCH); +} + +static Elf_Addr +ef_obj_symaddr(elf_file_t ef, Elf_Word symidx) +{ + const Elf_Sym *sym; + + if (symidx >= ef->ddbsymcnt) + return (0); + sym = ef->ddbsymtab + symidx; + + if (sym->st_shndx != SHN_UNDEF) + return (sym->st_value - (Elf_Addr)ef->address); + return (0); +} + +static int +ef_obj_read(elf_file_t ef, Elf_Off offset, size_t len, void *dest) +{ + ssize_t r; + + if (offset != (Elf_Off)-1) { + if (lseek(ef->ef_fd, offset, SEEK_SET) == -1) + return EIO; + } + + r = read(ef->ef_fd, dest, len); + if (r != -1 && (size_t)r == len) + return 0; + else + return EIO; +} + +static int +ef_obj_read_entry(elf_file_t ef, Elf_Off offset, size_t len, void **ptr) +{ + int error; + + *ptr = malloc(len); + if (*ptr == NULL) + return ENOMEM; + error = ef_obj_read(ef, offset, len, *ptr); + if (error) + free(*ptr); + return error; +} + +static int +ef_obj_seg_read(elf_file_t ef, Elf_Off offset, size_t len, void *dest) +{ + + if (offset + len > ef->size) { + if (ef->ef_verbose) + warnx("ef_seg_read_rel(%s): bad offset/len (%lx:%ld)", + ef->ef_name, (long)offset, (long)len); + return (EFAULT); + } + bcopy(ef->address + offset, dest, len); + return (0); +} + +static int +ef_obj_seg_read_rel(elf_file_t ef, Elf_Off offset, size_t len, void *dest) +{ + char *memaddr; + Elf_Rel *r; + Elf_Rela *a; + Elf_Off secoff; + int error, i, sec; + + if (offset + len > ef->size) { + if (ef->ef_verbose) + warnx("ef_seg_read_rel(%s): bad offset/len (%lx:%ld)", + ef->ef_name, (long)offset, (long)len); + return (EFAULT); + } + bcopy(ef->address + offset, dest, len); + + /* Find out which section contains the data. */ + memaddr = ef->address + offset; + sec = -1; + for (i = 0; i < ef->nprogtab; i++) { + if (ef->progtab[i].addr == NULL) + continue; + if (memaddr < (char *)ef->progtab[i].addr || memaddr + len > + (char *)ef->progtab[i].addr + ef->progtab[i].size) + continue; + sec = ef->progtab[i].sec; + secoff = memaddr - (char *)ef->progtab[i].addr; + break; + } + + if (sec == -1) + return (EFAULT); + + /* Now do the relocations. */ + for (i = 0; i < ef->nrel; i++) { + if (ef->reltab[i].sec != sec) + continue; + for (r = ef->reltab[i].rel; + r < &ef->reltab[i].rel[ef->reltab[i].nrel]; r++) { + error = ef_reloc(ef->ef_efile, r, EF_RELOC_REL, secoff, + len, dest); + if (error != 0) + return (error); + } + } + for (i = 0; i < ef->nrela; i++) { + if (ef->relatab[i].sec != sec) + continue; + for (a = ef->relatab[i].rela; + a < &ef->relatab[i].rela[ef->relatab[i].nrela]; a++) { + error = ef_reloc(ef->ef_efile, a, EF_RELOC_RELA, secoff, + len, dest); + if (error != 0) + return (error); + } + } + return (0); +} + +static int +ef_obj_seg_read_entry(elf_file_t ef, Elf_Off offset, size_t len, void **ptr) +{ + int error; + + *ptr = malloc(len); + if (*ptr == NULL) + return ENOMEM; + error = ef_obj_seg_read(ef, offset, len, *ptr); + if (error) + free(*ptr); + return error; +} + +static int +ef_obj_seg_read_entry_rel(elf_file_t ef, Elf_Off offset, size_t len, + void **ptr) +{ + int error; + + *ptr = malloc(len); + if (*ptr == NULL) + return ENOMEM; + error = ef_obj_seg_read_rel(ef, offset, len, *ptr); + if (error) + free(*ptr); + return error; +} + +int +ef_obj_open(const char *filename, struct elf_file *efile, int verbose) +{ + elf_file_t ef; + Elf_Ehdr *hdr; + Elf_Shdr *shdr; + Elf_Sym *es; + char *mapbase; + size_t mapsize; + int alignmask, error, fd, pb, ra, res, rl; + int i, j, nbytes, nsym, shstrindex, symstrindex, symtabindex; + + if (filename == NULL) + return EFTYPE; + if ((fd = open(filename, O_RDONLY)) == -1) + return errno; + + ef = malloc(sizeof(*ef)); + if (ef == NULL) { + close(fd); + return (ENOMEM); + } + + efile->ef_ef = ef; + efile->ef_ops = &ef_obj_file_ops; + + bzero(ef, sizeof(*ef)); + ef->ef_verbose = verbose; + ef->ef_fd = fd; + ef->ef_name = strdup(filename); + ef->ef_efile = efile; + hdr = (Elf_Ehdr *)&ef->ef_hdr; + + res = read(fd, hdr, sizeof(*hdr)); + error = EFTYPE; + if (res != sizeof(*hdr)) + goto out; + if (!IS_ELF(*hdr)) + goto out; + if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || + hdr->e_ident[EI_DATA] != ELF_TARG_DATA || + hdr->e_ident[EI_VERSION] != EV_CURRENT || + hdr->e_version != EV_CURRENT || hdr->e_machine != ELF_TARG_MACH || + hdr->e_type != ET_REL) + goto out; + + nbytes = hdr->e_shnum * hdr->e_shentsize; + if (nbytes == 0 || hdr->e_shoff == 0 || + hdr->e_shentsize != sizeof(Elf_Shdr)) + goto out; + + if (ef_obj_read_entry(ef, hdr->e_shoff, nbytes, (void**)&shdr) != 0) { + printf("ef_read_entry failed\n"); + goto out; + } + ef->e_shdr = shdr; + + /* Scan the section header for information and table sizing. */ + nsym = 0; + symtabindex = -1; + symstrindex = -1; + for (i = 0; i < hdr->e_shnum; i++) { + switch (shdr[i].sh_type) { + case SHT_PROGBITS: + case SHT_NOBITS: + ef->nprogtab++; + break; + case SHT_SYMTAB: + nsym++; + symtabindex = i; + symstrindex = shdr[i].sh_link; + break; + case SHT_REL: + ef->nrel++; + break; + case SHT_RELA: + ef->nrela++; + break; + case SHT_STRTAB: + break; + } + } + + if (ef->nprogtab == 0) { + warnx("%s: file has no contents", filename); + goto out; + } + if (nsym != 1) { + warnx("%s: file has no valid symbol table", filename); + goto out; + } + if (symstrindex < 0 || symstrindex > hdr->e_shnum || + shdr[symstrindex].sh_type != SHT_STRTAB) { + warnx("%s: file has invalid symbol strings", filename); + goto out; + } + + /* Allocate space for tracking the load chunks */ + if (ef->nprogtab != 0) + ef->progtab = calloc(ef->nprogtab, sizeof(*ef->progtab)); + if (ef->nrel != 0) + ef->reltab = calloc(ef->nrel, sizeof(*ef->reltab)); + if (ef->nrela != 0) + ef->relatab = calloc(ef->nrela, sizeof(*ef->relatab)); + if ((ef->nprogtab != 0 && ef->progtab == NULL) || + (ef->nrel != 0 && ef->reltab == NULL) || + (ef->nrela != 0 && ef->relatab == NULL)) { + printf("malloc failed\n"); + error = ENOMEM; + goto out; + } + + ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym); + if (ef_obj_read_entry(ef, shdr[symtabindex].sh_offset, + shdr[symtabindex].sh_size, (void**)&ef->ddbsymtab) != 0) { + printf("ef_read_entry failed\n"); + goto out; + } + + ef->ddbstrcnt = shdr[symstrindex].sh_size; + if (ef_obj_read_entry(ef, shdr[symstrindex].sh_offset, + shdr[symstrindex].sh_size, (void**)&ef->ddbstrtab) != 0) { + printf("ef_read_entry failed\n"); + goto out; + } + + /* Do we have a string table for the section names? */ + shstrindex = -1; + if (hdr->e_shstrndx != 0 && + shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) { + shstrindex = hdr->e_shstrndx; + ef->shstrcnt = shdr[shstrindex].sh_size; + if (ef_obj_read_entry(ef, shdr[shstrindex].sh_offset, + shdr[shstrindex].sh_size, (void**)&ef->shstrtab) != 0) { + printf("ef_read_entry failed\n"); + goto out; + } + } + + /* Size up code/data(progbits) and bss(nobits). */ + alignmask = 0; + mapsize = 0; + for (i = 0; i < hdr->e_shnum; i++) { + switch (shdr[i].sh_type) { + case SHT_PROGBITS: + case SHT_NOBITS: + alignmask = shdr[i].sh_addralign - 1; + mapsize += alignmask; + mapsize &= ~alignmask; + mapsize += shdr[i].sh_size; + break; + } + } + + /* We know how much space we need for the text/data/bss/etc. */ + ef->address = malloc(mapsize); + ef->size = mapsize; + if (ef->address == NULL) { + printf("malloc failed\n"); + goto out; + } + mapbase = ef->address; + + /* + * Now load code/data(progbits), zero bss(nobits), allocate + * space for and load relocs + */ + pb = 0; + rl = 0; + ra = 0; + alignmask = 0; + for (i = 0; i < hdr->e_shnum; i++) { + switch (shdr[i].sh_type) { + case SHT_PROGBITS: + case SHT_NOBITS: + alignmask = shdr[i].sh_addralign - 1; + mapbase += alignmask; + mapbase = (char *)((uintptr_t)mapbase & ~alignmask); + ef->progtab[pb].addr = (void *)(uintptr_t)mapbase; + if (shdr[i].sh_type == SHT_PROGBITS) { + ef->progtab[pb].name = "<>"; + if (ef_obj_read(ef, shdr[i].sh_offset, + shdr[i].sh_size, + ef->progtab[pb].addr) != 0) { + printf("failed to read progbits\n"); + goto out; + } + } else { + ef->progtab[pb].name = "<>"; + bzero(ef->progtab[pb].addr, shdr[i].sh_size); + } + ef->progtab[pb].size = shdr[i].sh_size; + ef->progtab[pb].sec = i; + if (ef->shstrtab && shdr[i].sh_name != 0) + ef->progtab[pb].name = + ef->shstrtab + shdr[i].sh_name; + + /* Update all symbol values with the offset. */ + for (j = 0; j < ef->ddbsymcnt; j++) { + es = &ef->ddbsymtab[j]; + if (es->st_shndx != i) + continue; + es->st_value += (Elf_Addr)ef->progtab[pb].addr; + } + mapbase += shdr[i].sh_size; + pb++; + break; + case SHT_REL: + ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel); + ef->reltab[rl].sec = shdr[i].sh_info; + if (ef_obj_read_entry(ef, shdr[i].sh_offset, + shdr[i].sh_size, (void**)&ef->reltab[rl].rel) != + 0) { + printf("ef_read_entry failed\n"); + goto out; + } + rl++; + break; + case SHT_RELA: + ef->relatab[ra].nrela = + shdr[i].sh_size / sizeof(Elf_Rela); + ef->relatab[ra].sec = shdr[i].sh_info; + if (ef_obj_read_entry(ef, shdr[i].sh_offset, + shdr[i].sh_size, (void**)&ef->relatab[ra].rela) != + 0) { + printf("ef_read_entry failed\n"); + goto out; + } + ra++; + break; + } + } + error = 0; +out: + if (error) + ef_obj_close(ef); + return error; +} + +static int +ef_obj_close(elf_file_t ef) +{ + int i; + + close(ef->ef_fd); + if (ef->ef_name) + free(ef->ef_name); + if (ef->e_shdr != NULL) + free(ef->e_shdr); + if (ef->size != 0) + free(ef->address); + if (ef->nprogtab != 0) + free(ef->progtab); + if (ef->nrel != 0) { + for (i = 0; i < ef->nrel; i++) + if (ef->reltab[i].rel != NULL) + free(ef->reltab[i].rel); + free(ef->reltab); + } + if (ef->nrela != 0) { + for (i = 0; i < ef->nrela; i++) + if (ef->relatab[i].rela != NULL) + free(ef->relatab[i].rela); + free(ef->relatab); + } + if (ef->ddbsymtab != NULL) + free(ef->ddbsymtab); + if (ef->ddbstrtab != NULL) + free(ef->ddbstrtab); + if (ef->shstrtab != NULL) + free(ef->shstrtab); + ef->ef_efile->ef_ops = NULL; + ef->ef_efile->ef_ef = NULL; + free(ef); + + return 0; +} diff --git a/usr.sbin/kldxref/kldxref.c b/usr.sbin/kldxref/kldxref.c index 4206795..3beed7a 100644 --- a/usr.sbin/kldxref/kldxref.c +++ b/usr.sbin/kldxref/kldxref.c @@ -210,9 +210,12 @@ read_kld(char *filename, char *kldname) printf("%s\n", filename); error = ef_open(filename, &ef, verbose); if (error) { - if (verbose) - warnc(error, "elf_open(%s)", filename); - return error; + error = ef_obj_open(filename, &ef, verbose); + if (error) { + if (verbose) + warnc(error, "elf_open(%s)", filename); + return error; + } } eftype = EF_GET_TYPE(&ef); if (eftype != EFT_KLD && eftype != EFT_KERNEL) { -- cgit v1.1