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 lastaddr
= roundup(lastaddr
, shdr
[i
].sh_addralign
);
225 shdr
[i
].sh_addr
= (Elf_Addr
)lastaddr
;
226 lastaddr
+= shdr
[i
].sh_size
;
233 for (i
= 0; i
< hdr
->e_shnum
; i
++) {
234 switch (shdr
[i
].sh_type
) {
238 shdr
[i
].sh_addr
= (Elf_Addr
)lastaddr
;
239 lastaddr
+= shdr
[i
].sh_size
;
244 printf("\nelf" __XSTRING(__ELF_WORD_SIZE
)
245 "_obj_loadimage: file has no valid symbol table\n");
248 lastaddr
= roundup(lastaddr
, shdr
[ef
->symtabindex
].sh_addralign
);
249 shdr
[ef
->symtabindex
].sh_addr
= (Elf_Addr
)lastaddr
;
250 lastaddr
+= shdr
[ef
->symtabindex
].sh_size
;
252 symstrindex
= shdr
[ef
->symtabindex
].sh_link
;
253 if (symstrindex
< 0 || symstrindex
>= hdr
->e_shnum
||
254 shdr
[symstrindex
].sh_type
!= SHT_STRTAB
) {
255 printf("\nelf" __XSTRING(__ELF_WORD_SIZE
)
256 "_obj_loadimage: file has invalid symbol strings\n");
259 lastaddr
= roundup(lastaddr
, shdr
[symstrindex
].sh_addralign
);
260 shdr
[symstrindex
].sh_addr
= (Elf_Addr
)lastaddr
;
261 lastaddr
+= shdr
[symstrindex
].sh_size
;
264 if (hdr
->e_shstrndx
== 0 || hdr
->e_shstrndx
>= hdr
->e_shnum
||
265 shdr
[hdr
->e_shstrndx
].sh_type
!= SHT_STRTAB
) {
266 printf("\nelf" __XSTRING(__ELF_WORD_SIZE
)
267 "_obj_loadimage: file has no section names\n");
270 ef
->shstrindex
= hdr
->e_shstrndx
;
271 lastaddr
= roundup(lastaddr
, shdr
[ef
->shstrindex
].sh_addralign
);
272 shdr
[ef
->shstrindex
].sh_addr
= (Elf_Addr
)lastaddr
;
273 lastaddr
+= shdr
[ef
->shstrindex
].sh_size
;
275 /* Relocation tables. */
276 for (i
= 0; i
< hdr
->e_shnum
; i
++) {
277 switch (shdr
[i
].sh_type
) {
280 lastaddr
= roundup(lastaddr
, shdr
[i
].sh_addralign
);
281 shdr
[i
].sh_addr
= (Elf_Addr
)lastaddr
;
282 lastaddr
+= shdr
[i
].sh_size
;
287 /* Clear the whole area, including bss regions. */
288 kern_bzero(firstaddr
, lastaddr
- firstaddr
);
290 /* Figure section with the lowest file offset we haven't loaded yet. */
291 for (cshdr
= NULL
; /* none */; /* none */)
294 * Find next section to load. The complexity of this loop is
295 * O(n^2), but with the number of sections being typically
296 * small, we do not care.
300 for (i
= 0; i
< hdr
->e_shnum
; i
++) {
301 if (shdr
[i
].sh_addr
== 0 ||
302 shdr
[i
].sh_type
== SHT_NOBITS
)
304 /* Skip sections that were loaded already. */
306 lshdr
->sh_offset
>= shdr
[i
].sh_offset
)
308 /* Find section with smallest offset. */
309 if (cshdr
== lshdr
||
310 cshdr
->sh_offset
> shdr
[i
].sh_offset
)
317 if (kern_pread(ef
->fd
, (vm_offset_t
)cshdr
->sh_addr
,
318 cshdr
->sh_size
, (off_t
)cshdr
->sh_offset
) != 0) {
319 printf("\nelf" __XSTRING(__ELF_WORD_SIZE
)
320 "_obj_loadimage: read failed\n");
325 file_addmetadata(fp
, MODINFOMD_SHDR
, shdrbytes
, shdr
);
327 res
= __elfN(obj_parse_modmetadata
)(fp
, ef
);
331 ret
= lastaddr
- firstaddr
;
332 fp
->f_addr
= firstaddr
;
334 printf("size 0x%lx at 0x%lx", (u_long
)ret
, (u_long
)firstaddr
);
341 #if defined(__i386__) && __ELF_WORD_SIZE == 64
342 struct mod_metadata64
{
343 int md_version
; /* structure version MDTV_* */
344 int md_type
; /* type of entry MDT_* */
345 u_int64_t md_data
; /* specific data */
346 u_int64_t md_cval
; /* common string label */
351 __elfN(obj_parse_modmetadata
)(struct preloaded_file
*fp
, elf_file_t ef
)
353 struct mod_metadata md
;
354 #if defined(__i386__) && __ELF_WORD_SIZE == 64
355 struct mod_metadata64 md64
;
357 struct mod_depend
*mdepend
;
358 struct mod_version mver
;
360 int error
, modcnt
, minfolen
;
361 Elf_Addr v
, p
, p_stop
;
363 if (__elfN(obj_lookup_set
)(fp
, ef
, "modmetadata_set", &p
, &p_stop
,
369 COPYOUT(p
, &v
, sizeof(v
));
370 error
= __elfN(obj_reloc_ptr
)(fp
, ef
, p
, &v
, sizeof(v
));
373 #if defined(__i386__) && __ELF_WORD_SIZE == 64
374 COPYOUT(v
, &md64
, sizeof(md64
));
375 error
= __elfN(obj_reloc_ptr
)(fp
, ef
, v
, &md64
, sizeof(md64
));
378 md
.md_version
= md64
.md_version
;
379 md
.md_type
= md64
.md_type
;
380 md
.md_cval
= (const char *)(uintptr_t)md64
.md_cval
;
381 md
.md_data
= (void *)(uintptr_t)md64
.md_data
;
383 COPYOUT(v
, &md
, sizeof(md
));
384 error
= __elfN(obj_reloc_ptr
)(fp
, ef
, v
, &md
, sizeof(md
));
388 p
+= sizeof(Elf_Addr
);
391 s
= strdupout((vm_offset_t
)md
.md_cval
);
392 minfolen
= sizeof(*mdepend
) + strlen(s
) + 1;
393 mdepend
= malloc(minfolen
);
396 COPYOUT((vm_offset_t
)md
.md_data
, mdepend
,
398 strcpy((char*)(mdepend
+ 1), s
);
400 file_addmetadata(fp
, MODINFOMD_DEPLIST
, minfolen
,
405 s
= strdupout((vm_offset_t
)md
.md_cval
);
406 COPYOUT((vm_offset_t
)md
.md_data
, &mver
, sizeof(mver
));
407 file_addmodule(fp
, s
, mver
.mv_version
, NULL
);
415 printf("unknown type %d\n", md
.md_type
);
423 __elfN(obj_lookup_set
)(struct preloaded_file
*fp __unused
, elf_file_t ef
,
424 const char* name
, Elf_Addr
*startp
, Elf_Addr
*stopp
, int *countp
)
429 vm_offset_t shstrtab
;
434 shstrtab
= shdr
[ef
->shstrindex
].sh_addr
;
436 for (i
= 0; i
< hdr
->e_shnum
; i
++) {
437 if (shdr
[i
].sh_type
!= SHT_PROGBITS
)
439 if (shdr
[i
].sh_name
== 0)
441 p
= strdupout(shstrtab
+ shdr
[i
].sh_name
);
442 if (strncmp(p
, "set_", 4) == 0 && strcmp(p
+ 4, name
) == 0) {
443 *startp
= shdr
[i
].sh_addr
;
444 *stopp
= shdr
[i
].sh_addr
+ shdr
[i
].sh_size
;
445 *countp
= (*stopp
- *startp
) / sizeof(Elf_Addr
);
456 * Apply any intra-module relocations to the value. p is the load address
457 * of the value and val/len is the value to be modified. This does NOT modify
458 * the image in-place, because this is done by kern_linker later on.
461 __elfN(obj_reloc_ptr
)(struct preloaded_file
*mp
, elf_file_t ef
, Elf_Addr p
,
462 void *val
, size_t len
)
470 int error
, i
, j
, nrel
, nrela
;
476 for (i
= 0; i
< hdr
->e_shnum
; i
++) {
477 if (shdr
[i
].sh_type
!= SHT_RELA
&& shdr
[i
].sh_type
!= SHT_REL
)
479 base
= shdr
[shdr
[i
].sh_info
].sh_addr
;
480 if (base
== 0 || shdr
[i
].sh_addr
== 0)
482 if (off
< base
|| off
+ len
> base
+
483 shdr
[shdr
[i
].sh_info
].sh_size
)
486 switch (shdr
[i
].sh_type
) {
488 abase
= (Elf_Rela
*)(intptr_t)shdr
[i
].sh_addr
;
490 nrela
= shdr
[i
].sh_size
/ sizeof(Elf_Rela
);
491 for (j
= 0; j
< nrela
; j
++) {
492 COPYOUT(abase
+ j
, &a
, sizeof(a
));
494 error
= __elfN(reloc
)(ef
, __elfN(obj_symaddr
),
495 &a
, ELF_RELOC_RELA
, base
, off
, val
, len
);
501 rbase
= (Elf_Rel
*)(intptr_t)shdr
[i
].sh_addr
;
503 nrel
= shdr
[i
].sh_size
/ sizeof(Elf_Rel
);
504 for (j
= 0; j
< nrel
; j
++) {
505 COPYOUT(rbase
+ j
, &r
, sizeof(r
));
507 error
= __elfN(reloc
)(ef
, __elfN(obj_symaddr
),
508 &r
, ELF_RELOC_REL
, base
, off
, val
, len
);
518 /* Look up the address of a specified symbol. */
520 __elfN(obj_symaddr
)(struct elf_file
*ef
, Elf_Size symidx
)
525 if (symidx
>= ef
->e_shdr
[ef
->symtabindex
].sh_size
/ sizeof(Elf_Sym
))
527 COPYOUT(ef
->e_shdr
[ef
->symtabindex
].sh_addr
+ symidx
* sizeof(Elf_Sym
),
529 if (sym
.st_shndx
== SHN_UNDEF
|| sym
.st_shndx
>= ef
->hdr
.e_shnum
)
531 base
= ef
->e_shdr
[sym
.st_shndx
].sh_addr
;
534 return (base
+ sym
.st_value
);