elf_machdep.c revision 330897 
1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright 1996-1998 John D. Polstra.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
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.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 *
27 *	from: src/sys/i386/i386/elf_machdep.c,v 1.20 2004/08/11 02:35:05 marcel
28 */
29
30#include <sys/cdefs.h>
31__FBSDID("$FreeBSD: stable/11/sys/mips/mips/elf_machdep.c 330897 2018-03-14 03:19:51Z eadler $");
32
33#include <sys/param.h>
34#include <sys/kernel.h>
35#include <sys/systm.h>
36#include <sys/exec.h>
37#include <sys/imgact.h>
38#include <sys/linker.h>
39#include <sys/sysent.h>
40#include <sys/imgact_elf.h>
41#include <sys/proc.h>
42#include <sys/syscall.h>
43#include <sys/signalvar.h>
44#include <sys/vnode.h>
45
46#include <vm/vm.h>
47#include <vm/pmap.h>
48#include <vm/vm_param.h>
49
50#include <machine/elf.h>
51#include <machine/md_var.h>
52#include <machine/cache.h>
53
54#ifdef __mips_n64
55struct sysentvec elf64_freebsd_sysvec = {
56	.sv_size	= SYS_MAXSYSCALL,
57	.sv_table	= sysent,
58	.sv_mask	= 0,
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_name	= "FreeBSD ELF64",
67	.sv_coredump	= __elfN(coredump),
68	.sv_imgact_try	= NULL,
69	.sv_minsigstksz	= MINSIGSTKSZ,
70	.sv_pagesize	= PAGE_SIZE,
71	.sv_minuser	= VM_MIN_ADDRESS,
72	.sv_maxuser	= VM_MAXUSER_ADDRESS,
73	.sv_usrstack	= USRSTACK,
74	.sv_psstrings	= PS_STRINGS,
75	.sv_stackprot	= VM_PROT_ALL,
76	.sv_copyout_strings = exec_copyout_strings,
77	.sv_setregs	= exec_setregs,
78	.sv_fixlimit	= NULL,
79	.sv_maxssiz	= NULL,
80	.sv_flags	= SV_ABI_FREEBSD | SV_LP64,
81	.sv_set_syscall_retval = cpu_set_syscall_retval,
82	.sv_fetch_syscall_args = cpu_fetch_syscall_args,
83	.sv_syscallnames = syscallnames,
84	.sv_schedtail	= NULL,
85	.sv_thread_detach = NULL,
86	.sv_trap	= 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_errsize	= 0,
115	.sv_errtbl	= NULL,
116	.sv_transtrap	= NULL,
117	.sv_fixup	= __elfN(freebsd_fixup),
118	.sv_sendsig	= sendsig,
119	.sv_sigcode	= sigcode,
120	.sv_szsigcode	= &szsigcode,
121	.sv_name	= "FreeBSD ELF32",
122	.sv_coredump	= __elfN(coredump),
123	.sv_imgact_try	= NULL,
124	.sv_minsigstksz	= MINSIGSTKSZ,
125	.sv_pagesize	= PAGE_SIZE,
126	.sv_minuser	= VM_MIN_ADDRESS,
127	.sv_maxuser	= VM_MAXUSER_ADDRESS,
128	.sv_usrstack	= USRSTACK,
129	.sv_psstrings	= PS_STRINGS,
130	.sv_stackprot	= VM_PROT_ALL,
131	.sv_copyout_strings = exec_copyout_strings,
132	.sv_setregs	= exec_setregs,
133	.sv_fixlimit	= NULL,
134	.sv_maxssiz	= NULL,
135	.sv_flags	= SV_ABI_FREEBSD | SV_ILP32,
136	.sv_set_syscall_retval = cpu_set_syscall_retval,
137	.sv_fetch_syscall_args = cpu_fetch_syscall_args,
138	.sv_syscallnames = syscallnames,
139	.sv_schedtail	= NULL,
140	.sv_thread_detach = NULL,
141	.sv_trap	= NULL,
142};
143
144static Elf32_Brandinfo freebsd_brand_info = {
145	.brand		= ELFOSABI_FREEBSD,
146	.machine	= EM_MIPS,
147	.compat_3_brand	= "FreeBSD",
148	.emul_path	= NULL,
149	.interp_path	= "/libexec/ld-elf.so.1",
150	.sysvec		= &elf32_freebsd_sysvec,
151	.interp_newpath	= NULL,
152	.flags		= 0
153};
154
155SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST,
156    (sysinit_cfunc_t) elf32_insert_brand_entry,
157    &freebsd_brand_info);
158
159void
160elf32_dump_thread(struct thread *td __unused, void *dst __unused,
161    size_t *off __unused)
162{
163}
164#endif
165
166/* Process one elf relocation with addend. */
167static int
168elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data,
169    int type, int local, elf_lookup_fn lookup)
170{
171	Elf32_Addr *where = (Elf32_Addr *)NULL;
172	Elf_Addr addr;
173	Elf_Addr addend = (Elf_Addr)0;
174	Elf_Word rtype = (Elf_Word)0, symidx;
175	const Elf_Rel *rel = NULL;
176	const Elf_Rela *rela = NULL;
177	int error;
178
179	/*
180	 * Stash R_MIPS_HI16 info so we can use it when processing R_MIPS_LO16
181	 */
182	static Elf_Addr ahl;
183	static Elf32_Addr *where_hi16;
184
185	switch (type) {
186	case ELF_RELOC_REL:
187		rel = (const Elf_Rel *)data;
188		where = (Elf32_Addr *) (relocbase + rel->r_offset);
189		rtype = ELF_R_TYPE(rel->r_info);
190		symidx = ELF_R_SYM(rel->r_info);
191		switch (rtype) {
192		case R_MIPS_64:
193			addend = *(Elf64_Addr *)where;
194			break;
195		default:
196			addend = *where;
197			break;
198		}
199
200		break;
201	case ELF_RELOC_RELA:
202		rela = (const Elf_Rela *)data;
203		where = (Elf32_Addr *) (relocbase + rela->r_offset);
204		addend = rela->r_addend;
205		rtype = ELF_R_TYPE(rela->r_info);
206		symidx = ELF_R_SYM(rela->r_info);
207		break;
208	default:
209		panic("unknown reloc type %d\n", type);
210	}
211
212	switch (rtype) {
213	case R_MIPS_NONE:	/* none */
214		break;
215
216	case R_MIPS_32:		/* S + A */
217		error = lookup(lf, symidx, 1, &addr);
218		if (error != 0)
219			return (-1);
220		addr += addend;
221		if (*where != addr)
222			*where = (Elf32_Addr)addr;
223		break;
224
225	case R_MIPS_26:		/* ((A << 2) | (P & 0xf0000000) + S) >> 2 */
226		error = lookup(lf, symidx, 1, &addr);
227		if (error != 0)
228			return (-1);
229
230		addend &= 0x03ffffff;
231		/*
232		 * Addendum for .rela R_MIPS_26 is not shifted right
233		 */
234		if (rela == NULL)
235			addend <<= 2;
236
237		addr += ((Elf_Addr)where & 0xf0000000) | addend;
238		addr >>= 2;
239
240		*where &= ~0x03ffffff;
241		*where |= addr & 0x03ffffff;
242		break;
243
244	case R_MIPS_64:		/* S + A */
245		error = lookup(lf, symidx, 1, &addr);
246		if (error != 0)
247			return (-1);
248		addr += addend;
249		if (*(Elf64_Addr*)where != addr)
250			*(Elf64_Addr*)where = addr;
251		break;
252
253	case R_MIPS_HI16:	/* ((AHL + S) - ((short)(AHL + S)) >> 16 */
254		if (rela != NULL) {
255			error = lookup(lf, symidx, 1, &addr);
256			if (error != 0)
257				return (-1);
258			addr += addend;
259			*where &= 0xffff0000;
260			*where |= ((((long long) addr + 0x8000LL) >> 16) & 0xffff);
261		}
262		else {
263			ahl = addend << 16;
264			where_hi16 = where;
265		}
266		break;
267
268	case R_MIPS_LO16:	/* AHL + S */
269		if (rela != NULL) {
270			error = lookup(lf, symidx, 1, &addr);
271			if (error != 0)
272				return (-1);
273			addr += addend;
274			*where &= 0xffff0000;
275			*where |= addr & 0xffff;
276		}
277		else {
278			ahl += (int16_t)addend;
279			error = lookup(lf, symidx, 1, &addr);
280			if (error != 0)
281				return (-1);
282
283			addend &= 0xffff0000;
284			addend |= (uint16_t)(ahl + addr);
285			*where = addend;
286
287			addend = *where_hi16;
288			addend &= 0xffff0000;
289			addend |= ((ahl + addr) - (int16_t)(ahl + addr)) >> 16;
290			*where_hi16 = addend;
291		}
292
293		break;
294
295	case R_MIPS_HIGHER:	/* %higher(A+S) */
296		error = lookup(lf, symidx, 1, &addr);
297		if (error != 0)
298			return (-1);
299		addr += addend;
300		*where &= 0xffff0000;
301		*where |= (((long long)addr + 0x80008000LL) >> 32) & 0xffff;
302		break;
303
304	case R_MIPS_HIGHEST:	/* %highest(A+S) */
305		error = lookup(lf, symidx, 1, &addr);
306		if (error != 0)
307			return (-1);
308		addr += addend;
309		*where &= 0xffff0000;
310		*where |= (((long long)addr + 0x800080008000LL) >> 48) & 0xffff;
311		break;
312
313	default:
314		printf("kldload: unexpected relocation type %d\n",
315			rtype);
316		return (-1);
317	}
318
319	return(0);
320}
321
322int
323elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type,
324    elf_lookup_fn lookup)
325{
326
327	return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup));
328}
329
330int
331elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data,
332    int type, elf_lookup_fn lookup)
333{
334
335	return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup));
336}
337
338int
339elf_cpu_load_file(linker_file_t lf __unused)
340{
341
342	/*
343	 * Sync the I and D caches to make sure our relocations are visible.
344	 */
345	mips_icache_sync_all();
346
347	return (0);
348}
349
350int
351elf_cpu_unload_file(linker_file_t lf __unused)
352{
353
354	return (0);
355}
356