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
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30
31 #include "opt_cpu.h"
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/proc.h>
40 #include <sys/sysent.h>
41 #include <sys/imgact_elf.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/npx.h>
53
54 struct sysentvec elf32_freebsd_sysvec = {
55 .sv_size = SYS_MAXSYSCALL,
56 .sv_table = sysent,
57 .sv_mask = 0,
58 .sv_errsize = 0,
59 .sv_errtbl = NULL,
60 .sv_transtrap = NULL,
61 .sv_fixup = __elfN(freebsd_fixup),
62 .sv_sendsig = sendsig,
63 .sv_sigcode = sigcode,
64 .sv_szsigcode = &szsigcode,
65 .sv_name = "FreeBSD ELF32",
66 .sv_coredump = __elfN(coredump),
67 .sv_imgact_try = NULL,
68 .sv_minsigstksz = MINSIGSTKSZ,
69 .sv_minuser = VM_MIN_ADDRESS,
70 .sv_maxuser = VM_MAXUSER_ADDRESS,
71 .sv_usrstack = USRSTACK,
72 .sv_psstrings = PS_STRINGS,
73 .sv_stackprot = VM_PROT_ALL,
74 .sv_copyout_strings = exec_copyout_strings,
75 .sv_setregs = exec_setregs,
76 .sv_fixlimit = NULL,
77 .sv_maxssiz = NULL,
78 .sv_flags = SV_ABI_FREEBSD | SV_ASLR | SV_IA32 | SV_ILP32 |
79 SV_SHP | SV_TIMEKEEP,
80 .sv_set_syscall_retval = cpu_set_syscall_retval,
81 .sv_fetch_syscall_args = cpu_fetch_syscall_args,
82 .sv_syscallnames = syscallnames,
83 .sv_shared_page_base = SHAREDPAGE,
84 .sv_shared_page_len = PAGE_SIZE,
85 .sv_schedtail = NULL,
86 .sv_thread_detach = NULL,
87 .sv_trap = NULL,
88 };
89 INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec);
90
91 static Elf32_Brandinfo freebsd_brand_info = {
92 .brand = ELFOSABI_FREEBSD,
93 .machine = EM_386,
94 .compat_3_brand = "FreeBSD",
95 .emul_path = NULL,
96 .interp_path = "/libexec/ld-elf.so.1",
97 .sysvec = &elf32_freebsd_sysvec,
98 .interp_newpath = NULL,
99 .brand_note = &elf32_freebsd_brandnote,
100 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
101 };
102
103 SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST,
104 (sysinit_cfunc_t) elf32_insert_brand_entry,
105 &freebsd_brand_info);
106
107 static Elf32_Brandinfo freebsd_brand_oinfo = {
108 .brand = ELFOSABI_FREEBSD,
109 .machine = EM_386,
110 .compat_3_brand = "FreeBSD",
111 .emul_path = NULL,
112 .interp_path = "/usr/libexec/ld-elf.so.1",
113 .sysvec = &elf32_freebsd_sysvec,
114 .interp_newpath = NULL,
115 .brand_note = &elf32_freebsd_brandnote,
116 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
117 };
118
119 SYSINIT(oelf32, SI_SUB_EXEC, SI_ORDER_ANY,
120 (sysinit_cfunc_t) elf32_insert_brand_entry,
121 &freebsd_brand_oinfo);
122
123 static Elf32_Brandinfo kfreebsd_brand_info = {
124 .brand = ELFOSABI_FREEBSD,
125 .machine = EM_386,
126 .compat_3_brand = "FreeBSD",
127 .emul_path = NULL,
128 .interp_path = "/lib/ld.so.1",
129 .sysvec = &elf32_freebsd_sysvec,
130 .interp_newpath = NULL,
131 .brand_note = &elf32_kfreebsd_brandnote,
132 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE_MANDATORY
133 };
134
135 SYSINIT(kelf32, SI_SUB_EXEC, SI_ORDER_ANY,
136 (sysinit_cfunc_t) elf32_insert_brand_entry,
137 &kfreebsd_brand_info);
138
139 void
140 elf32_dump_thread(struct thread *td, void *dst, size_t *off)
141 {
142 void *buf;
143 size_t len;
144
145 len = 0;
146 if (use_xsave) {
147 if (dst != NULL) {
148 npxgetregs(td);
149 len += elf32_populate_note(NT_X86_XSTATE,
150 get_pcb_user_save_td(td), dst,
151 cpu_max_ext_state_size, &buf);
152 *(uint64_t *)((char *)buf + X86_XSTATE_XCR0_OFFSET) =
153 xsave_mask;
154 } else
155 len += elf32_populate_note(NT_X86_XSTATE, NULL, NULL,
156 cpu_max_ext_state_size, NULL);
157 }
158 *off = len;
159 }
160
161 bool
162 elf_is_ifunc_reloc(Elf_Size r_info)
163 {
164
165 return (ELF_R_TYPE(r_info) == R_386_IRELATIVE);
166 }
167
168 #define ERI_LOCAL 0x0001
169
170 /* Process one elf relocation with addend. */
171 static int
172 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data,
173 int type, elf_lookup_fn lookup, int flags)
174 {
175 Elf_Addr *where;
176 Elf_Addr addr;
177 Elf_Addr addend;
178 Elf_Word rtype, symidx;
179 const Elf_Rel *rel;
180 const Elf_Rela *rela;
181 int error;
182
183 switch (type) {
184 case ELF_RELOC_REL:
185 rel = (const Elf_Rel *)data;
186 where = (Elf_Addr *) (relocbase + rel->r_offset);
187 addend = *where;
188 rtype = ELF_R_TYPE(rel->r_info);
189 symidx = ELF_R_SYM(rel->r_info);
190 break;
191 case ELF_RELOC_RELA:
192 rela = (const Elf_Rela *)data;
193 where = (Elf_Addr *) (relocbase + rela->r_offset);
194 addend = rela->r_addend;
195 rtype = ELF_R_TYPE(rela->r_info);
196 symidx = ELF_R_SYM(rela->r_info);
197 break;
198 default:
199 panic("unknown reloc type %d\n", type);
200 }
201
202 if ((flags & ERI_LOCAL) != 0) {
203 if (rtype == R_386_RELATIVE) { /* A + B */
204 addr = elf_relocaddr(lf, relocbase + addend);
205 if (*where != addr)
206 *where = addr;
207 }
208 return (0);
209 }
210
211 switch (rtype) {
212
213 case R_386_NONE: /* none */
214 break;
215
216 case R_386_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 = addr;
223 break;
224
225 case R_386_PC32: /* S + A - P */
226 error = lookup(lf, symidx, 1, &addr);
227 if (error != 0)
228 return -1;
229 addr += addend - (Elf_Addr)where;
230 if (*where != addr)
231 *where = addr;
232 break;
233
234 case R_386_COPY: /* none */
235 /*
236 * There shouldn't be copy relocations in kernel
237 * objects.
238 */
239 printf("kldload: unexpected R_COPY relocation\n");
240 return -1;
241 break;
242
243 case R_386_GLOB_DAT: /* S */
244 error = lookup(lf, symidx, 1, &addr);
245 if (error != 0)
246 return -1;
247 if (*where != addr)
248 *where = addr;
249 break;
250
251 case R_386_RELATIVE:
252 break;
253
254 case R_386_IRELATIVE:
255 addr = relocbase + addend;
256 addr = ((Elf_Addr (*)(void))addr)();
257 if (*where != addr)
258 *where = addr;
259 break;
260 default:
261 printf("kldload: unexpected relocation type %d\n",
262 rtype);
263 return -1;
264 }
265 return(0);
266 }
267
268 int
269 elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type,
270 elf_lookup_fn lookup)
271 {
272
273 return (elf_reloc_internal(lf, relocbase, data, type, lookup, 0));
274 }
275
276 int
277 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data,
278 int type, elf_lookup_fn lookup)
279 {
280
281 return (elf_reloc_internal(lf, relocbase, data, type, lookup,
282 ERI_LOCAL));
283 }
284
285 int
286 elf_cpu_load_file(linker_file_t lf __unused)
287 {
288
289 return (0);
290 }
291
292 int
293 elf_cpu_unload_file(linker_file_t lf __unused)
294 {
295
296 return (0);
297 }
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