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>
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 */
65 static int __elfN(obj_loadimage)(struct preloaded_file *mp, elf_file_t ef,
67 static int __elfN(obj_lookup_set)(struct preloaded_file *mp, elf_file_t ef,
68 const char *name, Elf_Addr *startp, Elf_Addr *stopp, int *countp);
69 static int __elfN(obj_reloc_ptr)(struct preloaded_file *mp, elf_file_t ef,
70 Elf_Addr p, void *val, size_t len);
71 static int __elfN(obj_parse_modmetadata)(struct preloaded_file *mp,
73 static Elf_Addr __elfN(obj_symaddr)(struct elf_file *ef, Elf_Size symidx);
75 const char *__elfN(obj_kerneltype) = "elf kernel";
76 const char *__elfN(obj_moduletype) = "elf obj module";
79 * Attempt to load the file (file) as an ELF module. It will be stored at
80 * (dest), and a pointer to a module structure describing the loaded object
81 * will be saved in (result).
84 __elfN(obj_loadfile)(char *filename, u_int64_t dest,
85 struct preloaded_file **result)
87 struct preloaded_file *fp, *kfp;
94 bzero(&ef, sizeof(struct elf_file));
97 * Open the image, read and validate the ELF header
99 if (filename == NULL) /* can't handle nameless */
101 if ((ef.fd = open(filename, O_RDONLY)) == -1)
105 bytes_read = read(ef.fd, hdr, sizeof(*hdr));
106 if (bytes_read != sizeof(*hdr)) {
107 err = EFTYPE; /* could be EIO, but may be small file */
116 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || /* Layout ? */
117 hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
118 hdr->e_ident[EI_VERSION] != EV_CURRENT || /* Version ? */
119 hdr->e_version != EV_CURRENT ||
120 hdr->e_machine != ELF_TARG_MACH || /* Machine ? */
121 hdr->e_type != ET_REL) {
126 if (hdr->e_shnum * hdr->e_shentsize == 0 || hdr->e_shoff == 0 ||
127 hdr->e_shentsize != sizeof(Elf_Shdr)) {
132 kfp = file_findfile(NULL, __elfN(obj_kerneltype));
134 printf("elf" __XSTRING(__ELF_WORD_SIZE)
135 "_obj_loadfile: can't load module before kernel\n");
140 if (archsw.arch_loadaddr != NULL)
141 dest = archsw.arch_loadaddr(LOAD_ELF, hdr, dest);
143 dest = roundup(dest, PAGE_SIZE);
146 * Ok, we think we should handle this.
150 printf("elf" __XSTRING(__ELF_WORD_SIZE)
151 "_obj_loadfile: cannot allocate module info\n");
155 fp->f_name = strdup(filename);
156 fp->f_type = strdup(__elfN(obj_moduletype));
158 printf("%s ", filename);
160 fp->f_size = __elfN(obj_loadimage)(fp, &ef, dest);
161 if (fp->f_size == 0 || fp->f_addr == 0)
164 /* save exec header as metadata */
165 file_addmetadata(fp, MODINFOMD_ELFHDR, sizeof(*hdr), hdr);
167 /* Load OK, return module pointer */
168 *result = (struct preloaded_file *)fp;
178 if (ef.e_shdr != NULL)
185 * With the file (fd) open on the image, and (ehdr) containing
186 * the Elf header, load the image at (off)
189 __elfN(obj_loadimage)(struct preloaded_file *fp, elf_file_t ef, u_int64_t off)
192 Elf_Shdr *shdr, *cshdr, *lshdr;
193 vm_offset_t firstaddr, lastaddr;
194 int i, nsym, res, ret, shdrbytes, symstrindex;
197 firstaddr = lastaddr = (vm_offset_t)off;
199 ef->off = (vm_offset_t)off;
201 /* Read in the section headers. */
202 shdrbytes = hdr->e_shnum * hdr->e_shentsize;
203 shdr = alloc_pread(ef->fd, (off_t)hdr->e_shoff, shdrbytes);
205 printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
206 "_obj_loadimage: read section headers failed\n");
212 * Decide where to load everything, but don't read it yet.
213 * We store the load address as a non-zero sh_addr value.
214 * Start with the code/data and bss.
216 for (i = 0; i < hdr->e_shnum; i++)
218 for (i = 0; i < hdr->e_shnum; i++) {
219 if (shdr[i].sh_size == 0)
221 switch (shdr[i].sh_type) {
224 #if defined(__i386__) || defined(__amd64__)
225 case SHT_X86_64_UNWIND:
227 lastaddr = roundup(lastaddr, shdr[i].sh_addralign);
228 shdr[i].sh_addr = (Elf_Addr)lastaddr;
229 lastaddr += shdr[i].sh_size;
236 for (i = 0; i < hdr->e_shnum; i++) {
237 switch (shdr[i].sh_type) {
241 shdr[i].sh_addr = (Elf_Addr)lastaddr;
242 lastaddr += shdr[i].sh_size;
247 printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
248 "_obj_loadimage: file has no valid symbol table\n");
251 lastaddr = roundup(lastaddr, shdr[ef->symtabindex].sh_addralign);
252 shdr[ef->symtabindex].sh_addr = (Elf_Addr)lastaddr;
253 lastaddr += shdr[ef->symtabindex].sh_size;
255 symstrindex = shdr[ef->symtabindex].sh_link;
256 if (symstrindex < 0 || symstrindex >= hdr->e_shnum ||
257 shdr[symstrindex].sh_type != SHT_STRTAB) {
258 printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
259 "_obj_loadimage: file has invalid symbol strings\n");
262 lastaddr = roundup(lastaddr, shdr[symstrindex].sh_addralign);
263 shdr[symstrindex].sh_addr = (Elf_Addr)lastaddr;
264 lastaddr += shdr[symstrindex].sh_size;
267 if (hdr->e_shstrndx == 0 || hdr->e_shstrndx >= hdr->e_shnum ||
268 shdr[hdr->e_shstrndx].sh_type != SHT_STRTAB) {
269 printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
270 "_obj_loadimage: file has no section names\n");
273 ef->shstrindex = hdr->e_shstrndx;
274 lastaddr = roundup(lastaddr, shdr[ef->shstrindex].sh_addralign);
275 shdr[ef->shstrindex].sh_addr = (Elf_Addr)lastaddr;
276 lastaddr += shdr[ef->shstrindex].sh_size;
278 /* Relocation tables. */
279 for (i = 0; i < hdr->e_shnum; i++) {
280 switch (shdr[i].sh_type) {
283 lastaddr = roundup(lastaddr, shdr[i].sh_addralign);
284 shdr[i].sh_addr = (Elf_Addr)lastaddr;
285 lastaddr += shdr[i].sh_size;
290 /* Clear the whole area, including bss regions. */
291 kern_bzero(firstaddr, lastaddr - firstaddr);
293 /* Figure section with the lowest file offset we haven't loaded yet. */
294 for (cshdr = NULL; /* none */; /* none */)
297 * Find next section to load. The complexity of this loop is
298 * O(n^2), but with the number of sections being typically
299 * small, we do not care.
303 for (i = 0; i < hdr->e_shnum; i++) {
304 if (shdr[i].sh_addr == 0 ||
305 shdr[i].sh_type == SHT_NOBITS)
307 /* Skip sections that were loaded already. */
309 lshdr->sh_offset >= shdr[i].sh_offset)
311 /* Find section with smallest offset. */
312 if (cshdr == lshdr ||
313 cshdr->sh_offset > shdr[i].sh_offset)
320 if (kern_pread(ef->fd, (vm_offset_t)cshdr->sh_addr,
321 cshdr->sh_size, (off_t)cshdr->sh_offset) != 0) {
322 printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
323 "_obj_loadimage: read failed\n");
328 file_addmetadata(fp, MODINFOMD_SHDR, shdrbytes, shdr);
330 res = __elfN(obj_parse_modmetadata)(fp, ef);
334 ret = lastaddr - firstaddr;
335 fp->f_addr = firstaddr;
337 printf("size 0x%lx at 0x%lx", (u_long)ret, (u_long)firstaddr);
344 #if defined(__i386__) && __ELF_WORD_SIZE == 64
345 struct mod_metadata64 {
346 int md_version; /* structure version MDTV_* */
347 int md_type; /* type of entry MDT_* */
348 u_int64_t md_data; /* specific data */
349 u_int64_t md_cval; /* common string label */
354 __elfN(obj_parse_modmetadata)(struct preloaded_file *fp, elf_file_t ef)
356 struct mod_metadata md;
357 #if defined(__i386__) && __ELF_WORD_SIZE == 64
358 struct mod_metadata64 md64;
360 struct mod_depend *mdepend;
361 struct mod_version mver;
363 int error, modcnt, minfolen;
364 Elf_Addr v, p, p_stop;
366 if (__elfN(obj_lookup_set)(fp, ef, "modmetadata_set", &p, &p_stop,
372 COPYOUT(p, &v, sizeof(v));
373 error = __elfN(obj_reloc_ptr)(fp, ef, p, &v, sizeof(v));
376 #if defined(__i386__) && __ELF_WORD_SIZE == 64
377 COPYOUT(v, &md64, sizeof(md64));
378 error = __elfN(obj_reloc_ptr)(fp, ef, v, &md64, sizeof(md64));
381 md.md_version = md64.md_version;
382 md.md_type = md64.md_type;
383 md.md_cval = (const char *)(uintptr_t)md64.md_cval;
384 md.md_data = (void *)(uintptr_t)md64.md_data;
386 COPYOUT(v, &md, sizeof(md));
387 error = __elfN(obj_reloc_ptr)(fp, ef, v, &md, sizeof(md));
391 p += sizeof(Elf_Addr);
394 s = strdupout((vm_offset_t)md.md_cval);
395 minfolen = sizeof(*mdepend) + strlen(s) + 1;
396 mdepend = malloc(minfolen);
399 COPYOUT((vm_offset_t)md.md_data, mdepend,
401 strcpy((char*)(mdepend + 1), s);
403 file_addmetadata(fp, MODINFOMD_DEPLIST, minfolen,
408 s = strdupout((vm_offset_t)md.md_cval);
409 COPYOUT((vm_offset_t)md.md_data, &mver, sizeof(mver));
410 file_addmodule(fp, s, mver.mv_version, NULL);
418 printf("unknown type %d\n", md.md_type);
426 __elfN(obj_lookup_set)(struct preloaded_file *fp, elf_file_t ef,
427 const char* name, Elf_Addr *startp, Elf_Addr *stopp, int *countp)
432 vm_offset_t shstrtab;
437 shstrtab = shdr[ef->shstrindex].sh_addr;
439 for (i = 0; i < hdr->e_shnum; i++) {
440 if (shdr[i].sh_type != SHT_PROGBITS)
442 if (shdr[i].sh_name == 0)
444 p = strdupout(shstrtab + shdr[i].sh_name);
445 if (strncmp(p, "set_", 4) == 0 && strcmp(p + 4, name) == 0) {
446 *startp = shdr[i].sh_addr;
447 *stopp = shdr[i].sh_addr + shdr[i].sh_size;
448 *countp = (*stopp - *startp) / sizeof(Elf_Addr);
459 * Apply any intra-module relocations to the value. p is the load address
460 * of the value and val/len is the value to be modified. This does NOT modify
461 * the image in-place, because this is done by kern_linker later on.
464 __elfN(obj_reloc_ptr)(struct preloaded_file *mp, elf_file_t ef, Elf_Addr p,
465 void *val, size_t len)
473 int error, i, j, nrel, nrela;
478 for (i = 0; i < hdr->e_shnum; i++) {
479 if (shdr[i].sh_type != SHT_RELA && shdr[i].sh_type != SHT_REL)
481 base = shdr[shdr[i].sh_info].sh_addr;
482 if (base == 0 || shdr[i].sh_addr == 0)
484 if (off < base || off + len > base +
485 shdr[shdr[i].sh_info].sh_size)
488 switch (shdr[i].sh_type) {
490 abase = (Elf_Rela *)(intptr_t)shdr[i].sh_addr;
492 nrela = shdr[i].sh_size / sizeof(Elf_Rela);
493 for (j = 0; j < nrela; j++) {
494 COPYOUT(abase + j, &a, sizeof(a));
496 error = __elfN(reloc)(ef, __elfN(obj_symaddr),
497 &a, ELF_RELOC_RELA, base, off, val, len);
503 rbase = (Elf_Rel *)(intptr_t)shdr[i].sh_addr;
505 nrel = shdr[i].sh_size / sizeof(Elf_Rel);
506 for (j = 0; j < nrel; j++) {
507 COPYOUT(rbase + j, &r, sizeof(r));
509 error = __elfN(reloc)(ef, __elfN(obj_symaddr),
510 &r, ELF_RELOC_REL, base, off, val, len);
520 /* Look up the address of a specified symbol. */
522 __elfN(obj_symaddr)(struct elf_file *ef, Elf_Size symidx)
527 if (symidx >= ef->e_shdr[ef->symtabindex].sh_size / sizeof(Elf_Sym))
529 COPYOUT(ef->e_shdr[ef->symtabindex].sh_addr + symidx * sizeof(Elf_Sym),
531 if (sym.st_shndx == SHN_UNDEF || sym.st_shndx >= ef->hdr.e_shnum)
533 base = ef->e_shdr[sym.st_shndx].sh_addr;
536 return (base + sym.st_value);