2 * Copyright (c) 2004 Ian Dowse <iedowse@freebsd.org>
3 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
4 * Copyright (c) 1998 Peter Wemm <peter@freebsd.org>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
32 #include <sys/param.h>
34 #include <sys/linker.h>
35 #include <sys/module.h>
38 #include <machine/elf.h>
41 #include <sys/link_elf.h>
43 #include "bootstrap.h"
45 #define COPYOUT(s,d,l) archsw.arch_copyout((vm_offset_t)(s), d, l)
47 #if defined(__i386__) && __ELF_WORD_SIZE == 64
50 #define ELF_TARG_CLASS ELFCLASS64
51 #define ELF_TARG_MACH EM_X86_64
54 typedef struct elf_file {
58 int symtabindex; /* Index of symbol table */
59 int shstrindex; /* Index of section name string table */
63 #ifdef LOADER_VERIEXEC_VECTX
68 #ifdef LOADER_VERIEXEC_VECTX
69 #define VECTX_HANDLE(ef) (ef)->vctx
71 #define VECTX_HANDLE(ef) (ef)->fd
74 static int __elfN(obj_loadimage)(struct preloaded_file *mp, elf_file_t ef,
76 static int __elfN(obj_lookup_set)(struct preloaded_file *mp, elf_file_t ef,
77 const char *name, Elf_Addr *startp, Elf_Addr *stopp, int *countp);
78 static int __elfN(obj_reloc_ptr)(struct preloaded_file *mp, elf_file_t ef,
79 Elf_Addr p, void *val, size_t len);
80 static int __elfN(obj_parse_modmetadata)(struct preloaded_file *mp,
82 static Elf_Addr __elfN(obj_symaddr)(struct elf_file *ef, Elf_Size symidx);
84 const char *__elfN(obj_kerneltype) = "elf kernel";
85 const char *__elfN(obj_moduletype) = "elf obj module";
88 * Attempt to load the file (file) as an ELF module. It will be stored at
89 * (dest), and a pointer to a module structure describing the loaded object
90 * will be saved in (result).
93 __elfN(obj_loadfile)(char *filename, uint64_t dest,
94 struct preloaded_file **result)
96 struct preloaded_file *fp, *kfp;
103 bzero(&ef, sizeof(struct elf_file));
106 * Open the image, read and validate the ELF header
108 if (filename == NULL) /* can't handle nameless */
110 if ((ef.fd = open(filename, O_RDONLY)) == -1)
112 #ifdef LOADER_VERIEXEC_VECTX
116 ef.vctx = vectx_open(ef.fd, filename, 0L, NULL, &verror, __func__);
118 printf("Unverified %s: %s\n", filename, ve_error_get());
127 bytes_read = VECTX_READ(VECTX_HANDLE(&ef), hdr, sizeof(*hdr));
128 if (bytes_read != sizeof(*hdr)) {
129 err = EFTYPE; /* could be EIO, but may be small file */
138 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || /* Layout ? */
139 hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
140 hdr->e_ident[EI_VERSION] != EV_CURRENT || /* Version ? */
141 hdr->e_version != EV_CURRENT ||
142 hdr->e_machine != ELF_TARG_MACH || /* Machine ? */
143 hdr->e_type != ET_REL) {
148 if (hdr->e_shnum * hdr->e_shentsize == 0 || hdr->e_shoff == 0 ||
149 hdr->e_shentsize != sizeof(Elf_Shdr)) {
154 #if defined(LOADER_VERIEXEC) && !defined(LOADER_VERIEXEC_VECTX)
155 if (verify_file(ef.fd, filename, bytes_read, VE_MUST, __func__) < 0) {
161 kfp = file_findfile(NULL, __elfN(obj_kerneltype));
163 printf("elf" __XSTRING(__ELF_WORD_SIZE)
164 "_obj_loadfile: can't load module before kernel\n");
169 if (archsw.arch_loadaddr != NULL)
170 dest = archsw.arch_loadaddr(LOAD_ELF, hdr, dest);
172 dest = roundup(dest, PAGE_SIZE);
175 * Ok, we think we should handle this.
179 printf("elf" __XSTRING(__ELF_WORD_SIZE)
180 "_obj_loadfile: cannot allocate module info\n");
184 fp->f_name = strdup(filename);
185 fp->f_type = strdup(__elfN(obj_moduletype));
187 if (module_verbose > MODULE_VERBOSE_SILENT)
188 printf("%s ", filename);
190 fp->f_size = __elfN(obj_loadimage)(fp, &ef, dest);
191 if (fp->f_size == 0 || fp->f_addr == 0)
194 /* save exec header as metadata */
195 file_addmetadata(fp, MODINFOMD_ELFHDR, sizeof(*hdr), hdr);
197 /* Load OK, return module pointer */
198 *result = (struct preloaded_file *)fp;
207 #ifdef LOADER_VERIEXEC_VECTX
208 if (!err && ef.vctx) {
211 verror = vectx_close(ef.vctx, VE_MUST, __func__);
219 if (ef.e_shdr != NULL)
226 * With the file (fd) open on the image, and (ehdr) containing
227 * the Elf header, load the image at (off)
230 __elfN(obj_loadimage)(struct preloaded_file *fp, elf_file_t ef, uint64_t off)
233 Elf_Shdr *shdr, *cshdr, *lshdr;
234 vm_offset_t firstaddr, lastaddr;
235 int i, nsym, res, ret, shdrbytes, symstrindex;
238 firstaddr = lastaddr = (vm_offset_t)off;
240 ef->off = (vm_offset_t)off;
242 /* Read in the section headers. */
243 shdrbytes = hdr->e_shnum * hdr->e_shentsize;
244 shdr = alloc_pread(VECTX_HANDLE(ef), (off_t)hdr->e_shoff, shdrbytes);
246 printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
247 "_obj_loadimage: read section headers failed\n");
253 * Decide where to load everything, but don't read it yet.
254 * We store the load address as a non-zero sh_addr value.
255 * Start with the code/data and bss.
257 for (i = 0; i < hdr->e_shnum; i++)
259 for (i = 0; i < hdr->e_shnum; i++) {
260 if (shdr[i].sh_size == 0)
262 switch (shdr[i].sh_type) {
265 #if defined(__i386__) || defined(__amd64__)
266 case SHT_X86_64_UNWIND:
270 if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
272 lastaddr = roundup(lastaddr, shdr[i].sh_addralign);
273 shdr[i].sh_addr = (Elf_Addr)lastaddr;
274 lastaddr += shdr[i].sh_size;
281 for (i = 0; i < hdr->e_shnum; i++) {
282 switch (shdr[i].sh_type) {
290 printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
291 "_obj_loadimage: file has no valid symbol table\n");
294 lastaddr = roundup(lastaddr, shdr[ef->symtabindex].sh_addralign);
295 shdr[ef->symtabindex].sh_addr = (Elf_Addr)lastaddr;
296 lastaddr += shdr[ef->symtabindex].sh_size;
298 symstrindex = shdr[ef->symtabindex].sh_link;
299 if (symstrindex < 0 || symstrindex >= hdr->e_shnum ||
300 shdr[symstrindex].sh_type != SHT_STRTAB) {
301 printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
302 "_obj_loadimage: file has invalid symbol strings\n");
305 lastaddr = roundup(lastaddr, shdr[symstrindex].sh_addralign);
306 shdr[symstrindex].sh_addr = (Elf_Addr)lastaddr;
307 lastaddr += shdr[symstrindex].sh_size;
310 if (hdr->e_shstrndx == 0 || hdr->e_shstrndx >= hdr->e_shnum ||
311 shdr[hdr->e_shstrndx].sh_type != SHT_STRTAB) {
312 printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
313 "_obj_loadimage: file has no section names\n");
316 ef->shstrindex = hdr->e_shstrndx;
317 lastaddr = roundup(lastaddr, shdr[ef->shstrindex].sh_addralign);
318 shdr[ef->shstrindex].sh_addr = (Elf_Addr)lastaddr;
319 lastaddr += shdr[ef->shstrindex].sh_size;
321 /* Relocation tables. */
322 for (i = 0; i < hdr->e_shnum; i++) {
323 switch (shdr[i].sh_type) {
326 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
328 lastaddr = roundup(lastaddr, shdr[i].sh_addralign);
329 shdr[i].sh_addr = (Elf_Addr)lastaddr;
330 lastaddr += shdr[i].sh_size;
335 /* Clear the whole area, including bss regions. */
336 kern_bzero(firstaddr, lastaddr - firstaddr);
338 /* Figure section with the lowest file offset we haven't loaded yet. */
339 for (cshdr = NULL; /* none */; /* none */)
342 * Find next section to load. The complexity of this loop is
343 * O(n^2), but with the number of sections being typically
344 * small, we do not care.
348 for (i = 0; i < hdr->e_shnum; i++) {
349 if (shdr[i].sh_addr == 0 ||
350 shdr[i].sh_type == SHT_NOBITS)
352 /* Skip sections that were loaded already. */
354 lshdr->sh_offset >= shdr[i].sh_offset)
356 /* Find section with smallest offset. */
357 if (cshdr == lshdr ||
358 cshdr->sh_offset > shdr[i].sh_offset)
365 if (kern_pread(VECTX_HANDLE(ef), (vm_offset_t)cshdr->sh_addr,
366 cshdr->sh_size, (off_t)cshdr->sh_offset) != 0) {
367 printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
368 "_obj_loadimage: read failed\n");
373 file_addmetadata(fp, MODINFOMD_SHDR, shdrbytes, shdr);
375 res = __elfN(obj_parse_modmetadata)(fp, ef);
379 ret = lastaddr - firstaddr;
380 fp->f_addr = firstaddr;
382 if (module_verbose > MODULE_VERBOSE_SILENT)
383 printf("size 0x%lx at 0x%lx", (u_long)ret, (u_long)firstaddr);
386 if (module_verbose > MODULE_VERBOSE_SILENT)
391 #if defined(__i386__) && __ELF_WORD_SIZE == 64
392 struct mod_metadata64 {
393 int md_version; /* structure version MDTV_* */
394 int md_type; /* type of entry MDT_* */
395 uint64_t md_data; /* specific data */
396 uint64_t md_cval; /* common string label */
401 __elfN(obj_parse_modmetadata)(struct preloaded_file *fp, elf_file_t ef)
403 struct mod_metadata md;
404 #if defined(__i386__) && __ELF_WORD_SIZE == 64
405 struct mod_metadata64 md64;
407 struct mod_depend *mdepend;
408 struct mod_version mver;
410 int error, modcnt, minfolen;
411 Elf_Addr v, p, p_stop;
413 if (__elfN(obj_lookup_set)(fp, ef, "modmetadata_set", &p, &p_stop,
419 COPYOUT(p, &v, sizeof(v));
420 error = __elfN(obj_reloc_ptr)(fp, ef, p, &v, sizeof(v));
423 #if defined(__i386__) && __ELF_WORD_SIZE == 64
424 COPYOUT(v, &md64, sizeof(md64));
425 error = __elfN(obj_reloc_ptr)(fp, ef, v, &md64, sizeof(md64));
428 md.md_version = md64.md_version;
429 md.md_type = md64.md_type;
430 md.md_cval = (const char *)(uintptr_t)md64.md_cval;
431 md.md_data = (void *)(uintptr_t)md64.md_data;
433 COPYOUT(v, &md, sizeof(md));
434 error = __elfN(obj_reloc_ptr)(fp, ef, v, &md, sizeof(md));
438 p += sizeof(Elf_Addr);
441 s = strdupout((vm_offset_t)md.md_cval);
442 minfolen = sizeof(*mdepend) + strlen(s) + 1;
443 mdepend = malloc(minfolen);
446 COPYOUT((vm_offset_t)md.md_data, mdepend,
448 strcpy((char*)(mdepend + 1), s);
450 file_addmetadata(fp, MODINFOMD_DEPLIST, minfolen,
455 s = strdupout((vm_offset_t)md.md_cval);
456 COPYOUT((vm_offset_t)md.md_data, &mver, sizeof(mver));
457 file_addmodule(fp, s, mver.mv_version, NULL);
465 printf("unknown type %d\n", md.md_type);
473 __elfN(obj_lookup_set)(struct preloaded_file *fp, elf_file_t ef,
474 const char* name, Elf_Addr *startp, Elf_Addr *stopp, int *countp)
479 vm_offset_t shstrtab;
484 shstrtab = shdr[ef->shstrindex].sh_addr;
486 for (i = 0; i < hdr->e_shnum; i++) {
487 if (shdr[i].sh_type != SHT_PROGBITS)
489 if (shdr[i].sh_name == 0)
491 p = strdupout(shstrtab + shdr[i].sh_name);
492 if (strncmp(p, "set_", 4) == 0 && strcmp(p + 4, name) == 0) {
493 *startp = shdr[i].sh_addr;
494 *stopp = shdr[i].sh_addr + shdr[i].sh_size;
495 *countp = (*stopp - *startp) / sizeof(Elf_Addr);
506 * Apply any intra-module relocations to the value. p is the load address
507 * of the value and val/len is the value to be modified. This does NOT modify
508 * the image in-place, because this is done by kern_linker later on.
511 __elfN(obj_reloc_ptr)(struct preloaded_file *mp, elf_file_t ef, Elf_Addr p,
512 void *val, size_t len)
520 int error, i, j, nrel, nrela;
525 for (i = 0; i < hdr->e_shnum; i++) {
526 if (shdr[i].sh_type != SHT_RELA && shdr[i].sh_type != SHT_REL)
528 base = shdr[shdr[i].sh_info].sh_addr;
529 if (base == 0 || shdr[i].sh_addr == 0)
531 if (off < base || off + len > base +
532 shdr[shdr[i].sh_info].sh_size)
535 switch (shdr[i].sh_type) {
537 abase = (Elf_Rela *)(intptr_t)shdr[i].sh_addr;
539 nrela = shdr[i].sh_size / sizeof(Elf_Rela);
540 for (j = 0; j < nrela; j++) {
541 COPYOUT(abase + j, &a, sizeof(a));
543 error = __elfN(reloc)(ef, __elfN(obj_symaddr),
544 &a, ELF_RELOC_RELA, base, off, val, len);
550 rbase = (Elf_Rel *)(intptr_t)shdr[i].sh_addr;
552 nrel = shdr[i].sh_size / sizeof(Elf_Rel);
553 for (j = 0; j < nrel; j++) {
554 COPYOUT(rbase + j, &r, sizeof(r));
556 error = __elfN(reloc)(ef, __elfN(obj_symaddr),
557 &r, ELF_RELOC_REL, base, off, val, len);
567 /* Look up the address of a specified symbol. */
569 __elfN(obj_symaddr)(struct elf_file *ef, Elf_Size symidx)
574 if (symidx >= ef->e_shdr[ef->symtabindex].sh_size / sizeof(Elf_Sym))
576 COPYOUT(ef->e_shdr[ef->symtabindex].sh_addr + symidx * sizeof(Elf_Sym),
578 if (sym.st_shndx == SHN_UNDEF || sym.st_shndx >= ef->hdr.e_shnum)
580 base = ef->e_shdr[sym.st_shndx].sh_addr;
583 return (base + sym.st_value);