1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
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 #include "opt_cpu.h"
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/reg.h>
38 #include <sys/proc.h>
39 #include <sys/sysent.h>
40 #include <sys/imgact_elf.h>
41 #include <sys/syscall.h>
42 #include <sys/signalvar.h>
43 #include <sys/vnode.h>
44
45 #include <vm/vm.h>
46 #include <vm/pmap.h>
47 #include <vm/vm_param.h>
48
49 #include <machine/elf.h>
50 #include <machine/md_var.h>
51 #include <machine/npx.h>
52
53 struct sysentvec elf32_freebsd_sysvec = {
54 .sv_size = SYS_MAXSYSCALL,
55 .sv_table = sysent,
56 .sv_fixup = __elfN(freebsd_fixup),
57 .sv_sendsig = sendsig,
58 .sv_sigcode = sigcode,
59 .sv_szsigcode = &szsigcode,
60 .sv_name = "FreeBSD ELF32",
61 .sv_coredump = __elfN(coredump),
62 .sv_elf_core_osabi = ELFOSABI_FREEBSD,
63 .sv_elf_core_abi_vendor = FREEBSD_ABI_VENDOR,
64 .sv_elf_core_prepare_notes = __elfN(prepare_notes),
65 .sv_minsigstksz = MINSIGSTKSZ,
66 .sv_minuser = VM_MIN_ADDRESS,
67 .sv_maxuser = VM_MAXUSER_ADDRESS,
68 .sv_usrstack = USRSTACK,
69 .sv_psstrings = PS_STRINGS,
70 .sv_psstringssz = sizeof(struct ps_strings),
71 .sv_stackprot = VM_PROT_ALL,
72 .sv_copyout_auxargs = __elfN(freebsd_copyout_auxargs),
73 .sv_copyout_strings = exec_copyout_strings,
74 .sv_setregs = exec_setregs,
75 .sv_fixlimit = NULL,
76 .sv_maxssiz = NULL,
77 .sv_flags = SV_ABI_FREEBSD | SV_ASLR | SV_IA32 | SV_ILP32 |
78 SV_SHP | SV_TIMEKEEP | SV_RNG_SEED_VER | SV_SIGSYS,
79 .sv_set_syscall_retval = cpu_set_syscall_retval,
80 .sv_fetch_syscall_args = cpu_fetch_syscall_args,
81 .sv_syscallnames = syscallnames,
82 .sv_shared_page_base = SHAREDPAGE,
83 .sv_shared_page_len = PAGE_SIZE,
84 .sv_schedtail = NULL,
85 .sv_thread_detach = NULL,
86 .sv_trap = NULL,
87 .sv_onexec_old = exec_onexec_old,
88 .sv_onexit = exit_onexit,
89 .sv_set_fork_retval = x86_set_fork_retval,
90 .sv_regset_begin = SET_BEGIN(__elfN(regset)),
91 .sv_regset_end = SET_LIMIT(__elfN(regset)),
92 };
93 INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec);
94
95 static Elf32_Brandinfo freebsd_brand_info = {
96 .brand = ELFOSABI_FREEBSD,
97 .machine = EM_386,
98 .compat_3_brand = "FreeBSD",
99 .interp_path = "/libexec/ld-elf.so.1",
100 .sysvec = &elf32_freebsd_sysvec,
101 .interp_newpath = NULL,
102 .brand_note = &elf32_freebsd_brandnote,
103 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
104 };
105
106 SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST,
107 (sysinit_cfunc_t) elf32_insert_brand_entry,
108 &freebsd_brand_info);
109
110 static Elf32_Brandinfo freebsd_brand_oinfo = {
111 .brand = ELFOSABI_FREEBSD,
112 .machine = EM_386,
113 .compat_3_brand = "FreeBSD",
114 .interp_path = "/usr/libexec/ld-elf.so.1",
115 .sysvec = &elf32_freebsd_sysvec,
116 .interp_newpath = NULL,
117 .brand_note = &elf32_freebsd_brandnote,
118 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
119 };
120
121 SYSINIT(oelf32, SI_SUB_EXEC, SI_ORDER_ANY,
122 (sysinit_cfunc_t) elf32_insert_brand_entry,
123 &freebsd_brand_oinfo);
124
125 static Elf32_Brandinfo kfreebsd_brand_info = {
126 .brand = ELFOSABI_FREEBSD,
127 .machine = EM_386,
128 .compat_3_brand = "FreeBSD",
129 .interp_path = "/lib/ld.so.1",
130 .sysvec = &elf32_freebsd_sysvec,
131 .interp_newpath = NULL,
132 .brand_note = &elf32_kfreebsd_brandnote,
133 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE_MANDATORY
134 };
135
136 SYSINIT(kelf32, SI_SUB_EXEC, SI_ORDER_ANY,
137 (sysinit_cfunc_t) elf32_insert_brand_entry,
138 &kfreebsd_brand_info);
139
140 void
elf32_dump_thread(struct thread * td,void * dst,size_t * off)141 elf32_dump_thread(struct thread *td, void *dst, size_t *off)
142 {
143 void *buf;
144 size_t len;
145
146 len = 0;
147 if (use_xsave) {
148 if (dst != NULL) {
149 npxgetregs(td);
150 len += elf32_populate_note(NT_X86_XSTATE,
151 get_pcb_user_save_td(td), dst,
152 cpu_max_ext_state_size, &buf);
153 *(uint64_t *)((char *)buf + X86_XSTATE_XCR0_OFFSET) =
154 xsave_mask;
155 } else
156 len += elf32_populate_note(NT_X86_XSTATE, NULL, NULL,
157 cpu_max_ext_state_size, NULL);
158 }
159 *off = len;
160 }
161
162 bool
elf_is_ifunc_reloc(Elf_Size r_info)163 elf_is_ifunc_reloc(Elf_Size r_info)
164 {
165
166 return (ELF_R_TYPE(r_info) == R_386_IRELATIVE);
167 }
168
169 #define ERI_LOCAL 0x0001
170
171 /* Process one elf relocation with addend. */
172 static int
elf_reloc_internal(linker_file_t lf,Elf_Addr relocbase,const void * data,int type,elf_lookup_fn lookup,int flags)173 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data,
174 int type, elf_lookup_fn lookup, int flags)
175 {
176 Elf_Addr *where;
177 Elf_Addr addr;
178 Elf_Addr addend;
179 Elf_Word rtype, symidx;
180 const Elf_Rel *rel;
181 const Elf_Rela *rela;
182 int error;
183
184 switch (type) {
185 case ELF_RELOC_REL:
186 rel = (const Elf_Rel *)data;
187 where = (Elf_Addr *) (relocbase + rel->r_offset);
188 addend = *where;
189 rtype = ELF_R_TYPE(rel->r_info);
190 symidx = ELF_R_SYM(rel->r_info);
191 break;
192 case ELF_RELOC_RELA:
193 rela = (const Elf_Rela *)data;
194 where = (Elf_Addr *) (relocbase + rela->r_offset);
195 addend = rela->r_addend;
196 rtype = ELF_R_TYPE(rela->r_info);
197 symidx = ELF_R_SYM(rela->r_info);
198 break;
199 default:
200 panic("unknown reloc type %d\n", type);
201 }
202
203 if ((flags & ERI_LOCAL) != 0) {
204 if (rtype == R_386_RELATIVE) { /* A + B */
205 addr = elf_relocaddr(lf, relocbase + addend);
206 if (*where != addr)
207 *where = addr;
208 }
209 return (0);
210 }
211
212 switch (rtype) {
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, "
240 "symbol index %d\n", symidx);
241 return (-1);
242 break;
243
244 case R_386_GLOB_DAT: /* S */
245 case R_386_JMP_SLOT: /* S */
246 error = lookup(lf, symidx, 1, &addr);
247 if (error != 0)
248 return (-1);
249 if (*where != addr)
250 *where = addr;
251 break;
252
253 case R_386_RELATIVE:
254 break;
255
256 case R_386_IRELATIVE:
257 addr = relocbase + addend;
258 addr = ((Elf_Addr (*)(void))addr)();
259 if (*where != addr)
260 *where = addr;
261 break;
262
263 default:
264 printf("kldload: unexpected relocation type %d, "
265 "symbol index %d\n", rtype, symidx);
266 return (-1);
267 }
268 return(0);
269 }
270
271 int
elf_reloc(linker_file_t lf,Elf_Addr relocbase,const void * data,int type,elf_lookup_fn lookup)272 elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type,
273 elf_lookup_fn lookup)
274 {
275
276 return (elf_reloc_internal(lf, relocbase, data, type, lookup, 0));
277 }
278
279 int
elf_reloc_local(linker_file_t lf,Elf_Addr relocbase,const void * data,int type,elf_lookup_fn lookup)280 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data,
281 int type, elf_lookup_fn lookup)
282 {
283
284 return (elf_reloc_internal(lf, relocbase, data, type, lookup,
285 ERI_LOCAL));
286 }
287
288 int
elf_cpu_load_file(linker_file_t lf __unused)289 elf_cpu_load_file(linker_file_t lf __unused)
290 {
291
292 return (0);
293 }
294
295 int
elf_cpu_unload_file(linker_file_t lf __unused)296 elf_cpu_unload_file(linker_file_t lf __unused)
297 {
298
299 return (0);
300 }
301
302 int
elf_cpu_parse_dynamic(caddr_t loadbase __unused,Elf_Dyn * dynamic __unused)303 elf_cpu_parse_dynamic(caddr_t loadbase __unused, Elf_Dyn *dynamic __unused)
304 {
305
306 return (0);
307 }
308