elf_machdep.c revision 293490 
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 293490 2016-01-09 14:53:08Z 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};
88
89static Elf64_Brandinfo freebsd_brand_info = {
90	.brand		= ELFOSABI_FREEBSD,
91	.machine	= EM_MIPS,
92	.compat_3_brand	= "FreeBSD",
93	.emul_path	= NULL,
94	.interp_path	= "/libexec/ld-elf.so.1",
95	.sysvec		= &elf64_freebsd_sysvec,
96	.interp_newpath	= NULL,
97	.flags		= 0
98};
99
100SYSINIT(elf64, SI_SUB_EXEC, SI_ORDER_ANY,
101    (sysinit_cfunc_t) elf64_insert_brand_entry,
102    &freebsd_brand_info);
103
104void
105elf64_dump_thread(struct thread *td __unused, void *dst __unused,
106    size_t *off __unused)
107{
108}
109#else
110struct sysentvec elf32_freebsd_sysvec = {
111	.sv_size	= SYS_MAXSYSCALL,
112	.sv_table	= sysent,
113	.sv_mask	= 0,
114	.sv_sigsize	= 0,
115	.sv_sigtbl	= NULL,
116	.sv_errsize	= 0,
117	.sv_errtbl	= NULL,
118	.sv_transtrap	= NULL,
119	.sv_fixup	= __elfN(freebsd_fixup),
120	.sv_sendsig	= sendsig,
121	.sv_sigcode	= sigcode,
122	.sv_szsigcode	= &szsigcode,
123	.sv_prepsyscall	= NULL,
124	.sv_name	= "FreeBSD ELF32",
125	.sv_coredump	= __elfN(coredump),
126	.sv_imgact_try	= NULL,
127	.sv_minsigstksz	= MINSIGSTKSZ,
128	.sv_pagesize	= PAGE_SIZE,
129	.sv_minuser	= VM_MIN_ADDRESS,
130	.sv_maxuser	= VM_MAXUSER_ADDRESS,
131	.sv_usrstack	= USRSTACK,
132	.sv_psstrings	= PS_STRINGS,
133	.sv_stackprot	= VM_PROT_ALL,
134	.sv_copyout_strings = exec_copyout_strings,
135	.sv_setregs	= exec_setregs,
136	.sv_fixlimit	= NULL,
137	.sv_maxssiz	= NULL,
138	.sv_flags	= SV_ABI_FREEBSD | SV_ILP32,
139	.sv_set_syscall_retval = cpu_set_syscall_retval,
140	.sv_fetch_syscall_args = cpu_fetch_syscall_args,
141	.sv_syscallnames = syscallnames,
142	.sv_schedtail	= NULL,
143	.sv_thread_detach = NULL,
144};
145
146static Elf32_Brandinfo freebsd_brand_info = {
147	.brand		= ELFOSABI_FREEBSD,
148	.machine	= EM_MIPS,
149	.compat_3_brand	= "FreeBSD",
150	.emul_path	= NULL,
151	.interp_path	= "/libexec/ld-elf.so.1",
152	.sysvec		= &elf32_freebsd_sysvec,
153	.interp_newpath	= NULL,
154	.flags		= 0
155};
156
157SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST,
158    (sysinit_cfunc_t) elf32_insert_brand_entry,
159    &freebsd_brand_info);
160
161void
162elf32_dump_thread(struct thread *td __unused, void *dst __unused,
163    size_t *off __unused)
164{
165}
166#endif
167
168/* Process one elf relocation with addend. */
169static int
170elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data,
171    int type, int local, elf_lookup_fn lookup)
172{
173	Elf32_Addr *where = (Elf32_Addr *)NULL;
174	Elf_Addr addr;
175	Elf_Addr addend = (Elf_Addr)0;
176	Elf_Word rtype = (Elf_Word)0, symidx;
177	const Elf_Rel *rel = NULL;
178	const Elf_Rela *rela = NULL;
179	int error;
180
181	/*
182	 * Stash R_MIPS_HI16 info so we can use it when processing R_MIPS_LO16
183	 */
184	static Elf_Addr ahl;
185	static Elf32_Addr *where_hi16;
186
187	switch (type) {
188	case ELF_RELOC_REL:
189		rel = (const Elf_Rel *)data;
190		where = (Elf32_Addr *) (relocbase + rel->r_offset);
191		rtype = ELF_R_TYPE(rel->r_info);
192		symidx = ELF_R_SYM(rel->r_info);
193		switch (rtype) {
194		case R_MIPS_64:
195			addend = *(Elf64_Addr *)where;
196			break;
197		default:
198			addend = *where;
199			break;
200		}
201
202		break;
203	case ELF_RELOC_RELA:
204		rela = (const Elf_Rela *)data;
205		where = (Elf32_Addr *) (relocbase + rela->r_offset);
206		addend = rela->r_addend;
207		rtype = ELF_R_TYPE(rela->r_info);
208		symidx = ELF_R_SYM(rela->r_info);
209		break;
210	default:
211		panic("unknown reloc type %d\n", type);
212	}
213
214	switch (rtype) {
215	case R_MIPS_NONE:	/* none */
216		break;
217
218	case R_MIPS_32:		/* S + A */
219		error = lookup(lf, symidx, 1, &addr);
220		if (error != 0)
221			return (-1);
222		addr += addend;
223		if (*where != addr)
224			*where = (Elf32_Addr)addr;
225		break;
226
227	case R_MIPS_26:		/* ((A << 2) | (P & 0xf0000000) + S) >> 2 */
228		error = lookup(lf, symidx, 1, &addr);
229		if (error != 0)
230			return (-1);
231
232		addend &= 0x03ffffff;
233		/*
234		 * Addendum for .rela R_MIPS_26 is not shifted right
235		 */
236		if (rela == NULL)
237			addend <<= 2;
238
239		addr += ((Elf_Addr)where & 0xf0000000) | addend;
240		addr >>= 2;
241
242		*where &= ~0x03ffffff;
243		*where |= addr & 0x03ffffff;
244		break;
245
246	case R_MIPS_64:		/* S + A */
247		error = lookup(lf, symidx, 1, &addr);
248		if (error != 0)
249			return (-1);
250		addr += addend;
251		if (*(Elf64_Addr*)where != addr)
252			*(Elf64_Addr*)where = addr;
253		break;
254
255	case R_MIPS_HI16:	/* ((AHL + S) - ((short)(AHL + S)) >> 16 */
256		if (rela != NULL) {
257			error = lookup(lf, symidx, 1, &addr);
258			if (error != 0)
259				return (-1);
260			addr += addend;
261			*where &= 0xffff0000;
262			*where |= ((((long long) addr + 0x8000LL) >> 16) & 0xffff);
263		}
264		else {
265			ahl = addend << 16;
266			where_hi16 = where;
267		}
268		break;
269
270	case R_MIPS_LO16:	/* AHL + S */
271		if (rela != NULL) {
272			error = lookup(lf, symidx, 1, &addr);
273			if (error != 0)
274				return (-1);
275			addr += addend;
276			*where &= 0xffff0000;
277			*where |= addr & 0xffff;
278		}
279		else {
280			ahl += (int16_t)addend;
281			error = lookup(lf, symidx, 1, &addr);
282			if (error != 0)
283				return (-1);
284
285			addend &= 0xffff0000;
286			addend |= (uint16_t)(ahl + addr);
287			*where = addend;
288
289			addend = *where_hi16;
290			addend &= 0xffff0000;
291			addend |= ((ahl + addr) - (int16_t)(ahl + addr)) >> 16;
292			*where_hi16 = addend;
293		}
294
295		break;
296
297	case R_MIPS_HIGHER:	/* %higher(A+S) */
298		error = lookup(lf, symidx, 1, &addr);
299		if (error != 0)
300			return (-1);
301		addr += addend;
302		*where &= 0xffff0000;
303		*where |= (((long long)addr + 0x80008000LL) >> 32) & 0xffff;
304		break;
305
306	case R_MIPS_HIGHEST:	/* %highest(A+S) */
307		error = lookup(lf, symidx, 1, &addr);
308		if (error != 0)
309			return (-1);
310		addr += addend;
311		*where &= 0xffff0000;
312		*where |= (((long long)addr + 0x800080008000LL) >> 48) & 0xffff;
313		break;
314
315	default:
316		printf("kldload: unexpected relocation type %d\n",
317			rtype);
318		return (-1);
319	}
320
321	return(0);
322}
323
324int
325elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type,
326    elf_lookup_fn lookup)
327{
328
329	return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup));
330}
331
332int
333elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data,
334    int type, elf_lookup_fn lookup)
335{
336
337	return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup));
338}
339
340int
341elf_cpu_load_file(linker_file_t lf __unused)
342{
343
344	/*
345	 * Sync the I and D caches to make sure our relocations are visible.
346	 */
347	mips_icache_sync_all();
348
349	return (0);
350}
351
352int
353elf_cpu_unload_file(linker_file_t lf __unused)
354{
355
356	return (0);
357}
358