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
28 * $FreeBSD: src/sys/boot/common/load_elf_obj.c,v 1.2 2005/12/18 04:52:35 marcel Exp $
31 #include <sys/param.h>
33 #include <sys/linker.h>
34 #include <sys/module.h>
37 #include <machine/elf.h>
42 #include "bootstrap.h"
44 #define COPYOUT(s,d,l) archsw.arch_copyout((vm_offset_t)(s), d, l)
46 #if defined(__i386__) && __ELF_WORD_SIZE == 64
49 #define ELF_TARG_CLASS ELFCLASS64
50 #define ELF_TARG_MACH EM_X86_64
53 typedef struct elf_file
{
57 int symtabindex
; /* Index of symbol table */
58 int shstrindex
; /* Index of section name string table */
64 static int __elfN(obj_loadimage
)(struct preloaded_file
*mp
, elf_file_t ef
,
66 static int __elfN(obj_lookup_set
)(struct preloaded_file
*mp
, elf_file_t ef
,
67 const char *name
, Elf_Addr
*startp
, Elf_Addr
*stopp
, int *countp
);
68 static int __elfN(obj_reloc_ptr
)(struct preloaded_file
*mp
, elf_file_t ef
,
69 Elf_Addr p
, void *val
, size_t len
);
70 static int __elfN(obj_parse_modmetadata
)(struct preloaded_file
*mp
,
72 static Elf_Addr
__elfN(obj_symaddr
)(struct elf_file
*ef
, Elf_Size symidx
);
74 const char *__elfN(obj_kerneltype
) = "elf kernel";
75 const char *__elfN(obj_moduletype
) = "elf obj module";
78 * Attempt to load the file (file) as an ELF module. It will be stored at
79 * (dest), and a pointer to a module structure describing the loaded object
80 * will be saved in (result).
83 __elfN(obj_loadfile
)(char *filename
, u_int64_t dest
,
84 struct preloaded_file
**result
)
86 struct preloaded_file
*fp
, *kfp
;
93 bzero(&ef
, sizeof(struct elf_file
));
96 * Open the image, read and validate the ELF header
98 if (filename
== NULL
) /* can't handle nameless */
100 if ((ef
.fd
= rel_open(filename
, NULL
, O_RDONLY
)) == -1)
104 bytes_read
= read(ef
.fd
, hdr
, sizeof(*hdr
));
105 if (bytes_read
!= sizeof(*hdr
)) {
106 err
= EFTYPE
; /* could be EIO, but may be small file */
115 if (hdr
->e_ident
[EI_CLASS
] != ELF_TARG_CLASS
|| /* Layout ? */
116 hdr
->e_ident
[EI_DATA
] != ELF_TARG_DATA
||
117 hdr
->e_ident
[EI_VERSION
] != EV_CURRENT
|| /* Version ? */
118 hdr
->e_version
!= EV_CURRENT
||
119 hdr
->e_machine
!= ELF_TARG_MACH
|| /* Machine ? */
120 hdr
->e_type
!= ET_REL
) {
125 if (hdr
->e_shnum
* hdr
->e_shentsize
== 0 || hdr
->e_shoff
== 0 ||
126 hdr
->e_shentsize
!= sizeof(Elf_Shdr
)) {
131 kfp
= file_findfile(NULL
, NULL
);
133 printf("elf" __XSTRING(__ELF_WORD_SIZE
)
134 "_obj_loadfile: can't load module before kernel\n");
138 if (strcmp(__elfN(obj_kerneltype
), kfp
->f_type
)) {
139 printf("elf" __XSTRING(__ELF_WORD_SIZE
)
140 "_obj_loadfile: can't load module with kernel type '%s'\n",
146 /* Page-align the load address */
147 dest
= roundup(dest
, PAGE_SIZE
);
150 * Ok, we think we should handle this.
154 printf("elf" __XSTRING(__ELF_WORD_SIZE
)
155 "_obj_loadfile: cannot allocate module info\n");
159 fp
->f_name
= strdup(filename
);
160 fp
->f_type
= strdup(__elfN(obj_moduletype
));
162 printf("%s ", filename
);
164 fp
->f_size
= __elfN(obj_loadimage
)(fp
, &ef
, dest
);
165 if (fp
->f_size
== 0 || fp
->f_addr
== 0)
168 /* save exec header as metadata */
169 file_addmetadata(fp
, MODINFOMD_ELFHDR
, sizeof(*hdr
), hdr
);
171 /* Load OK, return module pointer */
172 *result
= (struct preloaded_file
*)fp
;
182 if (ef
.e_shdr
!= NULL
)
189 * With the file (fd) open on the image, and (ehdr) containing
190 * the Elf header, load the image at (off)
193 __elfN(obj_loadimage
)(struct preloaded_file
*fp
, elf_file_t ef
, u_int64_t off
)
197 vm_offset_t firstaddr
, lastaddr
;
198 int i
, nsym
, res
, ret
, shdrbytes
, symstrindex
;
201 firstaddr
= lastaddr
= (vm_offset_t
)off
;
203 ef
->off
= (vm_offset_t
)off
;
205 /* Read in the section headers. */
206 shdrbytes
= hdr
->e_shnum
* hdr
->e_shentsize
;
207 shdr
= alloc_pread(ef
->fd
, (off_t
)hdr
->e_shoff
, shdrbytes
);
209 printf("\nelf" __XSTRING(__ELF_WORD_SIZE
)
210 "_obj_loadimage: read section headers failed\n");
216 * Decide where to load everything, but don't read it yet.
217 * We store the load address as a non-zero sh_addr value.
218 * Start with the code/data and bss.
220 for (i
= 0; i
< hdr
->e_shnum
; i
++) {
222 if (shdr
[i
].sh_size
== 0)
224 switch (shdr
[i
].sh_type
) {
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 /* Now read it all in. */
294 for (i
= 0; i
< hdr
->e_shnum
; i
++) {
295 if (shdr
[i
].sh_addr
== 0 || shdr
[i
].sh_type
== SHT_NOBITS
)
297 if (kern_pread(ef
->fd
, (vm_offset_t
)shdr
[i
].sh_addr
,
298 shdr
[i
].sh_size
, (off_t
)shdr
[i
].sh_offset
) != 0) {
299 printf("\nelf" __XSTRING(__ELF_WORD_SIZE
)
300 "_obj_loadimage: read failed\n");
305 file_addmetadata(fp
, MODINFOMD_SHDR
, shdrbytes
, shdr
);
307 res
= __elfN(obj_parse_modmetadata
)(fp
, ef
);
311 ret
= lastaddr
- firstaddr
;
312 fp
->f_addr
= firstaddr
;
314 printf("size 0x%lx at 0x%lx", (u_long
)ret
, (u_long
)firstaddr
);
321 #if defined(__i386__) && __ELF_WORD_SIZE == 64
322 struct mod_metadata64
{
323 int md_version
; /* structure version MDTV_* */
324 int md_type
; /* type of entry MDT_* */
325 u_int64_t md_data
; /* specific data */
326 u_int64_t md_cval
; /* common string label */
331 __elfN(obj_parse_modmetadata
)(struct preloaded_file
*fp
, elf_file_t ef
)
333 struct mod_metadata md
;
334 #if defined(__i386__) && __ELF_WORD_SIZE == 64
335 struct mod_metadata64 md64
;
337 struct mod_depend
*mdepend
;
338 struct mod_version mver
;
340 int error
, modcnt
, minfolen
;
341 Elf_Addr v
, p
, p_stop
;
343 if (__elfN(obj_lookup_set
)(fp
, ef
, "modmetadata_set", &p
, &p_stop
,
349 COPYOUT(p
, &v
, sizeof(v
));
350 error
= __elfN(obj_reloc_ptr
)(fp
, ef
, p
, &v
, sizeof(v
));
353 #if defined(__i386__) && __ELF_WORD_SIZE == 64
354 COPYOUT(v
, &md64
, sizeof(md64
));
355 error
= __elfN(obj_reloc_ptr
)(fp
, ef
, v
, &md64
, sizeof(md64
));
358 md
.md_version
= md64
.md_version
;
359 md
.md_type
= md64
.md_type
;
360 md
.md_cval
= (const char *)(uintptr_t)md64
.md_cval
;
361 md
.md_data
= (void *)(uintptr_t)md64
.md_data
;
363 COPYOUT(v
, &md
, sizeof(md
));
364 error
= __elfN(obj_reloc_ptr
)(fp
, ef
, v
, &md
, sizeof(md
));
368 p
+= sizeof(Elf_Addr
);
371 s
= strdupout((vm_offset_t
)md
.md_cval
);
372 minfolen
= sizeof(*mdepend
) + strlen(s
) + 1;
373 mdepend
= malloc(minfolen
);
376 COPYOUT((vm_offset_t
)md
.md_data
, mdepend
,
378 strcpy((char*)(mdepend
+ 1), s
);
380 file_addmetadata(fp
, MODINFOMD_DEPLIST
, minfolen
,
385 s
= strdupout((vm_offset_t
)md
.md_cval
);
386 COPYOUT((vm_offset_t
)md
.md_data
, &mver
, sizeof(mver
));
387 file_addmodule(fp
, s
, mver
.mv_version
, NULL
);
394 printf("unknown type %d\n", md
.md_type
);
402 __elfN(obj_lookup_set
)(struct preloaded_file
*fp
, elf_file_t ef
,
403 const char* name
, Elf_Addr
*startp
, Elf_Addr
*stopp
, int *countp
)
408 vm_offset_t shstrtab
;
413 shstrtab
= shdr
[ef
->shstrindex
].sh_addr
;
415 for (i
= 0; i
< hdr
->e_shnum
; i
++) {
416 if (shdr
[i
].sh_type
!= SHT_PROGBITS
)
418 if (shdr
[i
].sh_name
== 0)
420 p
= strdupout(shstrtab
+ shdr
[i
].sh_name
);
421 if (strncmp(p
, "set_", 4) == 0 && strcmp(p
+ 4, name
) == 0) {
422 *startp
= shdr
[i
].sh_addr
;
423 *stopp
= shdr
[i
].sh_addr
+ shdr
[i
].sh_size
;
424 *countp
= (*stopp
- *startp
) / sizeof(Elf_Addr
);
435 * Apply any intra-module relocations to the value. p is the load address
436 * of the value and val/len is the value to be modified. This does NOT modify
437 * the image in-place, because this is done by kern_linker later on.
440 __elfN(obj_reloc_ptr
)(struct preloaded_file
*mp
, elf_file_t ef
, Elf_Addr p
,
441 void *val
, size_t len
)
449 int error
, i
, j
, nrel
, nrela
;
454 for (i
= 0; i
< hdr
->e_shnum
; i
++) {
455 if (shdr
[i
].sh_type
!= SHT_RELA
&& shdr
[i
].sh_type
!= SHT_REL
)
457 base
= shdr
[shdr
[i
].sh_info
].sh_addr
;
458 if (base
== 0 || shdr
[i
].sh_addr
== 0)
460 if (off
< base
|| off
+ len
> base
+
461 shdr
[shdr
[i
].sh_info
].sh_size
)
464 switch (shdr
[i
].sh_type
) {
466 abase
= (Elf_Rela
*)(intptr_t)shdr
[i
].sh_addr
;
468 nrela
= shdr
[i
].sh_size
/ sizeof(Elf_Rela
);
469 for (j
= 0; j
< nrela
; j
++) {
470 COPYOUT(abase
+ j
, &a
, sizeof(a
));
472 error
= __elfN(reloc
)(ef
, __elfN(obj_symaddr
),
473 &a
, ELF_RELOC_RELA
, base
, off
, val
, len
);
479 rbase
= (Elf_Rel
*)(intptr_t)shdr
[i
].sh_addr
;
481 nrel
= shdr
[i
].sh_size
/ sizeof(Elf_Rel
);
482 for (j
= 0; j
< nrel
; j
++) {
483 COPYOUT(rbase
+ j
, &r
, sizeof(r
));
485 error
= __elfN(reloc
)(ef
, __elfN(obj_symaddr
),
486 &r
, ELF_RELOC_REL
, base
, off
, val
, len
);
496 /* Look up the address of a specified symbol. */
498 __elfN(obj_symaddr
)(struct elf_file
*ef
, Elf_Size symidx
)
503 if (symidx
>= ef
->e_shdr
[ef
->symtabindex
].sh_size
/ sizeof(Elf_Sym
))
505 COPYOUT(ef
->e_shdr
[ef
->symtabindex
].sh_addr
+ symidx
* sizeof(Elf_Sym
),
507 if (sym
.st_shndx
== SHN_UNDEF
|| sym
.st_shndx
>= ef
->hdr
.e_shnum
)
509 base
= ef
->e_shdr
[sym
.st_shndx
].sh_addr
;
512 return (base
+ sym
.st_value
);