elf_machdep.c revision 294136 
1/*-
2 * Copyright 1996-1998 John D. Polstra.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
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.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 *
25 *	from: src/sys/i386/i386/elf_machdep.c,v 1.20 2004/08/11 02:35:05 marcel
26 */
27
28#include <sys/cdefs.h>
29__FBSDID("$FreeBSD: stable/10/sys/mips/mips/elf_machdep.c 294136 2016-01-16 07:56:49Z dchagin $");
30
31#include <sys/param.h>
32#include <sys/kernel.h>
33#include <sys/systm.h>
34#include <sys/exec.h>
35#include <sys/imgact.h>
36#include <sys/linker.h>
37#include <sys/sysent.h>
38#include <sys/imgact_elf.h>
39#include <sys/proc.h>
40#include <sys/syscall.h>
41#include <sys/signalvar.h>
42#include <sys/vnode.h>
43
44#include <vm/vm.h>
45#include <vm/pmap.h>
46#include <vm/vm_param.h>
47
48#include <machine/elf.h>
49#include <machine/md_var.h>
50#include <machine/cache.h>
51
52#ifdef __mips_n64
53struct sysentvec elf64_freebsd_sysvec = {
54	.sv_size	= SYS_MAXSYSCALL,
55	.sv_table	= sysent,
56	.sv_mask	= 0,
57	.sv_sigsize	= 0,
58	.sv_sigtbl	= NULL,
59	.sv_errsize	= 0,
60	.sv_errtbl	= NULL,
61	.sv_transtrap	= NULL,
62	.sv_fixup	= __elfN(freebsd_fixup),
63	.sv_sendsig	= sendsig,
64	.sv_sigcode	= sigcode,
65	.sv_szsigcode	= &szsigcode,
66	.sv_prepsyscall	= NULL,
67	.sv_name	= "FreeBSD ELF64",
68	.sv_coredump	= __elfN(coredump),
69	.sv_imgact_try	= NULL,
70	.sv_minsigstksz	= MINSIGSTKSZ,
71	.sv_pagesize	= PAGE_SIZE,
72	.sv_minuser	= VM_MIN_ADDRESS,
73	.sv_maxuser	= VM_MAXUSER_ADDRESS,
74	.sv_usrstack	= USRSTACK,
75	.sv_psstrings	= PS_STRINGS,
76	.sv_stackprot	= VM_PROT_ALL,
77	.sv_copyout_strings = exec_copyout_strings,
78	.sv_setregs	= exec_setregs,
79	.sv_fixlimit	= NULL,
80	.sv_maxssiz	= NULL,
81	.sv_flags	= SV_ABI_FREEBSD | SV_LP64,
82	.sv_set_syscall_retval = cpu_set_syscall_retval,
83	.sv_fetch_syscall_args = cpu_fetch_syscall_args,
84	.sv_syscallnames = syscallnames,
85	.sv_schedtail	= NULL,
86	.sv_thread_detach = NULL,
87	.sv_trap	= NULL,
88};
89
90static Elf64_Brandinfo freebsd_brand_info = {
91	.brand		= ELFOSABI_FREEBSD,
92	.machine	= EM_MIPS,
93	.compat_3_brand	= "FreeBSD",
94	.emul_path	= NULL,
95	.interp_path	= "/libexec/ld-elf.so.1",
96	.sysvec		= &elf64_freebsd_sysvec,
97	.interp_newpath	= NULL,
98	.flags		= 0
99};
100
101SYSINIT(elf64, SI_SUB_EXEC, SI_ORDER_ANY,
102    (sysinit_cfunc_t) elf64_insert_brand_entry,
103    &freebsd_brand_info);
104
105void
106elf64_dump_thread(struct thread *td __unused, void *dst __unused,
107    size_t *off __unused)
108{
109}
110#else
111struct sysentvec elf32_freebsd_sysvec = {
112	.sv_size	= SYS_MAXSYSCALL,
113	.sv_table	= sysent,
114	.sv_mask	= 0,
115	.sv_sigsize	= 0,
116	.sv_sigtbl	= NULL,
117	.sv_errsize	= 0,
118	.sv_errtbl	= NULL,
119	.sv_transtrap	= NULL,
120	.sv_fixup	= __elfN(freebsd_fixup),
121	.sv_sendsig	= sendsig,
122	.sv_sigcode	= sigcode,
123	.sv_szsigcode	= &szsigcode,
124	.sv_prepsyscall	= NULL,
125	.sv_name	= "FreeBSD ELF32",
126	.sv_coredump	= __elfN(coredump),
127	.sv_imgact_try	= NULL,
128	.sv_minsigstksz	= MINSIGSTKSZ,
129	.sv_pagesize	= PAGE_SIZE,
130	.sv_minuser	= VM_MIN_ADDRESS,
131	.sv_maxuser	= VM_MAXUSER_ADDRESS,
132	.sv_usrstack	= USRSTACK,
133	.sv_psstrings	= PS_STRINGS,
134	.sv_stackprot	= VM_PROT_ALL,
135	.sv_copyout_strings = exec_copyout_strings,
136	.sv_setregs	= exec_setregs,
137	.sv_fixlimit	= NULL,
138	.sv_maxssiz	= NULL,
139	.sv_flags	= SV_ABI_FREEBSD | SV_ILP32,
140	.sv_set_syscall_retval = cpu_set_syscall_retval,
141	.sv_fetch_syscall_args = cpu_fetch_syscall_args,
142	.sv_syscallnames = syscallnames,
143	.sv_schedtail	= NULL,
144	.sv_thread_detach = NULL,
145	.sv_trap	= NULL,
146};
147
148static Elf32_Brandinfo freebsd_brand_info = {
149	.brand		= ELFOSABI_FREEBSD,
150	.machine	= EM_MIPS,
151	.compat_3_brand	= "FreeBSD",
152	.emul_path	= NULL,
153	.interp_path	= "/libexec/ld-elf.so.1",
154	.sysvec		= &elf32_freebsd_sysvec,
155	.interp_newpath	= NULL,
156	.flags		= 0
157};
158
159SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST,
160    (sysinit_cfunc_t) elf32_insert_brand_entry,
161    &freebsd_brand_info);
162
163void
164elf32_dump_thread(struct thread *td __unused, void *dst __unused,
165    size_t *off __unused)
166{
167}
168#endif
169
170/* Process one elf relocation with addend. */
171static int
172elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data,
173    int type, int local, elf_lookup_fn lookup)
174{
175	Elf32_Addr *where = (Elf32_Addr *)NULL;
176	Elf_Addr addr;
177	Elf_Addr addend = (Elf_Addr)0;
178	Elf_Word rtype = (Elf_Word)0, symidx;
179	const Elf_Rel *rel = NULL;
180	const Elf_Rela *rela = NULL;
181	int error;
182
183	/*
184	 * Stash R_MIPS_HI16 info so we can use it when processing R_MIPS_LO16
185	 */
186	static Elf_Addr ahl;
187	static Elf32_Addr *where_hi16;
188
189	switch (type) {
190	case ELF_RELOC_REL:
191		rel = (const Elf_Rel *)data;
192		where = (Elf32_Addr *) (relocbase + rel->r_offset);
193		rtype = ELF_R_TYPE(rel->r_info);
194		symidx = ELF_R_SYM(rel->r_info);
195		switch (rtype) {
196		case R_MIPS_64:
197			addend = *(Elf64_Addr *)where;
198			break;
199		default:
200			addend = *where;
201			break;
202		}
203
204		break;
205	case ELF_RELOC_RELA:
206		rela = (const Elf_Rela *)data;
207		where = (Elf32_Addr *) (relocbase + rela->r_offset);
208		addend = rela->r_addend;
209		rtype = ELF_R_TYPE(rela->r_info);
210		symidx = ELF_R_SYM(rela->r_info);
211		break;
212	default:
213		panic("unknown reloc type %d\n", type);
214	}
215
216	switch (rtype) {
217	case R_MIPS_NONE:	/* none */
218		break;
219
220	case R_MIPS_32:		/* S + A */
221		error = lookup(lf, symidx, 1, &addr);
222		if (error != 0)
223			return (-1);
224		addr += addend;
225		if (*where != addr)
226			*where = (Elf32_Addr)addr;
227		break;
228
229	case R_MIPS_26:		/* ((A << 2) | (P & 0xf0000000) + S) >> 2 */
230		error = lookup(lf, symidx, 1, &addr);
231		if (error != 0)
232			return (-1);
233
234		addend &= 0x03ffffff;
235		/*
236		 * Addendum for .rela R_MIPS_26 is not shifted right
237		 */
238		if (rela == NULL)
239			addend <<= 2;
240
241		addr += ((Elf_Addr)where & 0xf0000000) | addend;
242		addr >>= 2;
243
244		*where &= ~0x03ffffff;
245		*where |= addr & 0x03ffffff;
246		break;
247
248	case R_MIPS_64:		/* S + A */
249		error = lookup(lf, symidx, 1, &addr);
250		if (error != 0)
251			return (-1);
252		addr += addend;
253		if (*(Elf64_Addr*)where != addr)
254			*(Elf64_Addr*)where = addr;
255		break;
256
257	case R_MIPS_HI16:	/* ((AHL + S) - ((short)(AHL + S)) >> 16 */
258		if (rela != NULL) {
259			error = lookup(lf, symidx, 1, &addr);
260			if (error != 0)
261				return (-1);
262			addr += addend;
263			*where &= 0xffff0000;
264			*where |= ((((long long) addr + 0x8000LL) >> 16) & 0xffff);
265		}
266		else {
267			ahl = addend << 16;
268			where_hi16 = where;
269		}
270		break;
271
272	case R_MIPS_LO16:	/* AHL + S */
273		if (rela != NULL) {
274			error = lookup(lf, symidx, 1, &addr);
275			if (error != 0)
276				return (-1);
277			addr += addend;
278			*where &= 0xffff0000;
279			*where |= addr & 0xffff;
280		}
281		else {
282			ahl += (int16_t)addend;
283			error = lookup(lf, symidx, 1, &addr);
284			if (error != 0)
285				return (-1);
286
287			addend &= 0xffff0000;
288			addend |= (uint16_t)(ahl + addr);
289			*where = addend;
290
291			addend = *where_hi16;
292			addend &= 0xffff0000;
293			addend |= ((ahl + addr) - (int16_t)(ahl + addr)) >> 16;
294			*where_hi16 = addend;
295		}
296
297		break;
298
299	case R_MIPS_HIGHER:	/* %higher(A+S) */
300		error = lookup(lf, symidx, 1, &addr);
301		if (error != 0)
302			return (-1);
303		addr += addend;
304		*where &= 0xffff0000;
305		*where |= (((long long)addr + 0x80008000LL) >> 32) & 0xffff;
306		break;
307
308	case R_MIPS_HIGHEST:	/* %highest(A+S) */
309		error = lookup(lf, symidx, 1, &addr);
310		if (error != 0)
311			return (-1);
312		addr += addend;
313		*where &= 0xffff0000;
314		*where |= (((long long)addr + 0x800080008000LL) >> 48) & 0xffff;
315		break;
316
317	default:
318		printf("kldload: unexpected relocation type %d\n",
319			rtype);
320		return (-1);
321	}
322
323	return(0);
324}
325
326int
327elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type,
328    elf_lookup_fn lookup)
329{
330
331	return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup));
332}
333
334int
335elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data,
336    int type, elf_lookup_fn lookup)
337{
338
339	return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup));
340}
341
342int
343elf_cpu_load_file(linker_file_t lf __unused)
344{
345
346	/*
347	 * Sync the I and D caches to make sure our relocations are visible.
348	 */
349	mips_icache_sync_all();
350
351	return (0);
352}
353
354int
355elf_cpu_unload_file(linker_file_t lf __unused)
356{
357
358	return (0);
359}
360