2 * Copyright (c) 1997 Doug Rabson
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * $FreeBSD: src/sys/kern/link_aout.c,v 1.26 1999/12/24 15:33:36 bde Exp $
27 * $DragonFly: src/sys/kern/link_aout.c,v 1.6 2003/08/07 21:17:23 dillon Exp $
32 #define FREEBSD_AOUT 1
34 #include <sys/param.h>
35 #include <sys/kernel.h>
36 #include <sys/systm.h>
37 #include <sys/types.h>
38 #include <sys/malloc.h>
40 #include <sys/namei.h>
41 #include <sys/fcntl.h>
42 #include <sys/vnode.h>
43 #include <sys/linker.h>
45 #include <vm/vm_zone.h>
50 #include <machine/vmparam.h>
53 #include <machine/exec.h>
54 #include <sys/imgact_aout.h>
55 #include <machine/reloc.h>
56 #define _AOUT_INCLUDE_
57 #include <sys/nlist_aout.h>
58 #include <sys/link_aout.h>
60 static int link_aout_load_module(const char*, linker_file_t*);
62 static int link_aout_load_file(const char*, linker_file_t*);
64 static int link_aout_lookup_symbol(linker_file_t, const char*,
66 static int link_aout_symbol_values(linker_file_t file, c_linker_sym_t sym,
67 linker_symval_t* symval);
68 static int link_aout_search_symbol(linker_file_t lf, caddr_t value,
69 c_linker_sym_t* sym, long* diffp);
70 static void link_aout_unload_file(linker_file_t);
71 static void link_aout_unload_module(linker_file_t);
73 static struct linker_class_ops link_aout_class_ops = {
74 link_aout_load_module,
77 static struct linker_file_ops link_aout_file_ops = {
78 link_aout_lookup_symbol,
79 link_aout_symbol_values,
80 link_aout_search_symbol,
81 link_aout_unload_file,
83 static struct linker_file_ops link_aout_module_ops = {
84 link_aout_lookup_symbol,
85 link_aout_symbol_values,
86 link_aout_search_symbol,
87 link_aout_unload_module,
90 typedef struct aout_file {
91 char* address; /* Load address */
92 struct _dynamic* dynamic; /* Symbol table etc. */
95 static int load_dependancies(linker_file_t lf);
96 static int relocate_file(linker_file_t lf);
99 * The kernel symbol table starts here.
101 extern struct _dynamic _DYNAMIC;
104 link_aout_init(void* arg)
107 struct _dynamic* dp = &_DYNAMIC;
110 linker_add_class("a.out", NULL, &link_aout_class_ops);
116 af = malloc(sizeof(struct aout_file), M_LINKER, M_NOWAIT);
118 panic("link_aout_init: Can't create linker structures for kernel");
119 bzero(af, sizeof(*af));
124 linker_make_file(kernelname, af, &link_aout_file_ops);
125 if (linker_kernel_file == NULL)
126 panic("link_aout_init: Can't create linker structures for kernel");
127 linker_kernel_file->address = (caddr_t) KERNBASE;
128 linker_kernel_file->size = -(long)linker_kernel_file->address;
129 linker_current_file = linker_kernel_file;
130 linker_kernel_file->flags |= LINKER_FILE_LINKED;
135 SYSINIT(link_aout, SI_SUB_KLD, SI_ORDER_THIRD, link_aout_init, 0);
138 link_aout_load_module(const char* filename, linker_file_t* result)
140 caddr_t modptr, baseptr;
147 /* Look to see if we have the module preloaded. */
148 if ((modptr = preload_search_by_name(filename)) == NULL)
149 return(link_aout_load_file(filename, result));
151 /* It's preloaded, check we can handle it and collect information. */
152 if (((type = (char *)preload_search_info(modptr, MODINFO_TYPE)) == NULL) ||
153 strcmp(type, "a.out module") ||
154 ((baseptr = preload_search_info(modptr, MODINFO_ADDR)) == NULL) ||
155 ((ehdr = (struct exec *)preload_search_info(modptr, MODINFO_METADATA | MODINFOMD_AOUTEXEC)) == NULL))
156 return(0); /* we can't handle this */
158 /* Looks like we can handle this one */
159 af = malloc(sizeof(struct aout_file), M_LINKER, M_WAITOK);
160 bzero(af, sizeof(*af));
161 af->address = baseptr;
163 /* Assume _DYNAMIC is the first data item. */
164 af->dynamic = (struct _dynamic*)(af->address + ehdr->a_text);
165 if (af->dynamic->d_version != LD_VERSION_BSD) {
167 return(0); /* we can't handle this */
169 af->dynamic->d_un.d_sdt = (struct section_dispatch_table *)
170 ((char *)af->dynamic->d_un.d_sdt + (vm_offset_t)af->address);
172 /* Register with kld */
173 lf = linker_make_file(filename, af, &link_aout_module_ops);
178 lf->address = af->address;
179 lf->size = ehdr->a_text + ehdr->a_data + ehdr->a_bss;
181 /* Try to load dependancies */
182 if (((error = load_dependancies(lf)) != 0) ||
183 ((error = relocate_file(lf)) != 0)) {
184 linker_file_unload(lf);
187 lf->flags |= LINKER_FILE_LINKED;
193 link_aout_load_file(const char* filename, linker_file_t* result)
196 struct thread *td = curthread;
197 struct proc *p = td->td_proc;
207 pathname = linker_search_path(filename);
208 if (pathname == NULL)
210 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, pathname, td);
211 error = vn_open(&nd, FREAD, 0);
212 free(pathname, M_LINKER);
215 NDFREE(&nd, NDF_ONLY_PNBUF);
218 * Read the a.out header from the file.
220 error = vn_rdwr(UIO_READ, nd.ni_vp, (void*) &header, sizeof header, 0,
221 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid, td);
225 if (N_BADMAG(header) || !(N_GETFLAG(header) & EX_DYNAMIC))
229 * We have an a.out file, so make some space to read it in.
231 af = malloc(sizeof(struct aout_file), M_LINKER, M_WAITOK);
232 bzero(af, sizeof(*af));
233 af->address = malloc(header.a_text + header.a_data + header.a_bss,
237 * Read the text and data sections and zero the bss.
239 error = vn_rdwr(UIO_READ, nd.ni_vp, (void*) af->address,
240 header.a_text + header.a_data, 0,
241 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid, td);
244 bzero(af->address + header.a_text + header.a_data, header.a_bss);
247 * Assume _DYNAMIC is the first data item.
249 af->dynamic = (struct _dynamic*) (af->address + header.a_text);
250 if (af->dynamic->d_version != LD_VERSION_BSD) {
251 free(af->address, M_LINKER);
255 af->dynamic->d_un.d_sdt = (struct section_dispatch_table *)
256 ((char *)af->dynamic->d_un.d_sdt + (vm_offset_t)af->address);
258 lf = linker_make_file(filename, af, &link_aout_file_ops);
260 free(af->address, M_LINKER);
265 lf->address = af->address;
266 lf->size = header.a_text + header.a_data + header.a_bss;
268 if ((error = load_dependancies(lf)) != 0
269 || (error = relocate_file(lf)) != 0) {
270 linker_file_unload(lf);
274 lf->flags |= LINKER_FILE_LINKED;
278 VOP_UNLOCK(nd.ni_vp, 0, td);
279 vn_close(nd.ni_vp, FREAD, td);
285 link_aout_unload_file(linker_file_t file)
287 aout_file_t af = file->priv;
291 free(af->address, M_LINKER);
297 link_aout_unload_module(linker_file_t file)
299 aout_file_t af = file->priv;
304 preload_delete_name(file->filename);
307 #define AOUT_RELOC(af, type, off) (type*) ((af)->address + (off))
310 load_dependancies(linker_file_t lf)
312 aout_file_t af = lf->priv;
321 * All files are dependant on /kernel.
323 if (linker_kernel_file) {
324 linker_kernel_file->refs++;
325 linker_file_add_dependancy(lf, linker_kernel_file);
328 off = LD_NEED(af->dynamic);
331 * Load the dependancies.
334 sodp = AOUT_RELOC(af, struct sod, off);
335 name = AOUT_RELOC(af, char, sodp->sod_name);
337 error = linker_load_file(name, &lfdep);
340 error = linker_file_add_dependancy(lf, lfdep);
343 off = sodp->sod_next;
348 free(filename, M_TEMP);
353 * XXX i386 dependant.
356 read_relocation(struct relocation_info* r, char* addr)
358 int length = r->r_length;
360 return *(u_char*) addr;
361 else if (length == 1)
362 return *(u_short*) addr;
363 else if (length == 2)
364 return *(u_int*) addr;
366 printf("link_aout: unsupported relocation size %d\n", r->r_length);
371 write_relocation(struct relocation_info* r, char* addr, long value)
373 int length = r->r_length;
375 *(u_char*) addr = value;
376 else if (length == 1)
377 *(u_short*) addr = value;
378 else if (length == 2)
379 *(u_int*) addr = value;
381 printf("link_aout: unsupported relocation size %d\n", r->r_length);
385 relocate_file(linker_file_t lf)
387 aout_file_t af = lf->priv;
388 struct relocation_info* rel;
389 struct relocation_info* erel;
390 struct relocation_info* r;
391 struct nzlist* symbolbase;
397 rel = AOUT_RELOC(af, struct relocation_info, LD_REL(af->dynamic));
398 erel = AOUT_RELOC(af, struct relocation_info,
399 LD_REL(af->dynamic) + LD_RELSZ(af->dynamic));
400 symbolbase = AOUT_RELOC(af, struct nzlist, LD_SYMBOL(af->dynamic));
401 stringbase = AOUT_RELOC(af, char, LD_STRINGS(af->dynamic));
403 for (r = rel; r < erel; r++) {
406 if (r->r_address == 0)
409 addr = AOUT_RELOC(af, char, r->r_address);
411 np = &symbolbase[r->r_symbolnum];
412 sym = &stringbase[np->nz_strx];
415 printf("link_aout: bad symbol name %s\n", sym);
416 printf("link_aout: symbol %s not found\n", sym);
419 if (linker_file_lookup_symbol(lf, sym + 1,
420 (np->nz_type != (N_SETV+N_EXT)), (caddr_t *)&relocation)) {
421 printf("link_aout: symbol %s not found\n", sym);
426 relocation += read_relocation(r, addr);
429 printf("link_aout: can't cope with jump table relocations\n");
434 relocation -= (intptr_t) af->address;
437 printf("link_aout: can't cope with copy relocations\n");
441 write_relocation(r, addr, relocation);
443 write_relocation(r, addr,
444 (intptr_t)(read_relocation(r, addr) + af->address));
453 symbol_hash_value(aout_file_t af, const char* name)
458 hashval = '_'; /* fake a starting '_' for C symbols */
459 for (p = name; *p; p++)
460 hashval = (hashval << 1) + *p;
462 return (hashval & 0x7fffffff) % LD_BUCKETS(af->dynamic);
466 link_aout_lookup_symbol(linker_file_t file, const char* name,
469 aout_file_t af = file->priv;
471 struct rrs_hash* hashbase;
472 struct nzlist* symbolbase;
478 if (LD_BUCKETS(af->dynamic) == 0)
481 hashbase = AOUT_RELOC(af, struct rrs_hash, LD_HASH(af->dynamic));
482 symbolbase = AOUT_RELOC(af, struct nzlist, LD_SYMBOL(af->dynamic));
483 stringbase = AOUT_RELOC(af, char, LD_STRINGS(af->dynamic));
486 hashval = symbol_hash_value(af, name);
487 hp = &hashbase[hashval];
488 if (hp->rh_symbolnum == -1)
492 np = (struct nzlist *) &symbolbase[hp->rh_symbolnum];
493 cp = stringbase + np->nz_strx;
495 * Note: we fake the leading '_' for C symbols.
497 if (cp[0] == '_' && !strcmp(cp + 1, name))
500 if (hp->rh_next == 0)
503 hp = &hashbase[hp->rh_next];
513 * Check for an aliased symbol, whatever that is.
515 if (np->nz_type == N_INDR+N_EXT) {
516 name = stringbase + (++np)->nz_strx + 1; /* +1 for '_' */
521 * Check this is an actual definition of the symbol.
523 if (np->nz_value == 0)
526 if (np->nz_type == N_UNDF+N_EXT && np->nz_value != 0) {
527 if (np->nz_other == AUX_FUNC)
532 *sym = (linker_sym_t) np;
539 link_aout_symbol_values(linker_file_t file, c_linker_sym_t sym,
540 linker_symval_t* symval)
542 aout_file_t af = file->priv;
543 const struct nzlist* np = (const struct nzlist*) sym;
545 long numsym = LD_STABSZ(af->dynamic) / sizeof(struct nzlist);
546 struct nzlist *symbase;
548 /* Is it one of ours? It could be another module... */
549 symbase = AOUT_RELOC(af, struct nzlist, LD_SYMBOL(af->dynamic));
552 if ((np - symbase) > numsym)
555 stringbase = AOUT_RELOC(af, char, LD_STRINGS(af->dynamic));
557 symval->name = stringbase + np->nz_strx + 1; /* +1 for '_' */
558 if (np->nz_type == N_UNDF+N_EXT && np->nz_value != 0) {
560 symval->size = np->nz_value;
562 symval->value = AOUT_RELOC(af, char, np->nz_value);
563 symval->size = np->nz_size;
569 link_aout_search_symbol(linker_file_t lf, caddr_t value,
570 c_linker_sym_t* sym, long* diffp)
572 aout_file_t af = lf->priv;
573 u_long off = (uintptr_t) (void *) value;
578 struct nzlist* best = 0;
580 for (sp = AOUT_RELOC(af, struct nzlist, LD_SYMBOL(af->dynamic)),
581 ep = (struct nzlist *) ((caddr_t) sp + LD_STABSZ(af->dynamic));
583 if (sp->nz_name == 0)
585 sp_nz_value = sp->nz_value + (uintptr_t) (void *) af->address;
586 if (off >= sp_nz_value) {
587 if (off - sp_nz_value < diff) {
588 diff = off - sp_nz_value;
592 } else if (off - sp_nz_value == diff) {
601 *sym = (linker_sym_t) best;
606 #endif /* !__alpha__ */