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/param.h>
29 #include <sys/kernel.h>
30 #include <sys/systm.h>
31 #include <sys/exec.h>
32 #include <sys/imgact.h>
33 #include <sys/linker.h>
34 #include <sys/proc.h>
35 #include <sys/reg.h>
36 #include <sys/sysent.h>
37 #include <sys/imgact_elf.h>
38 #include <sys/syscall.h>
39 #include <sys/signalvar.h>
40 #include <sys/vnode.h>
41
42 #include <vm/vm.h>
43 #include <vm/pmap.h>
44 #include <vm/vm_param.h>
45
46 #include <machine/elf.h>
47 #include <machine/fpu.h>
48 #include <machine/md_var.h>
49
50 #include "vdso_offsets.h"
51
52 extern const char _binary_elf_vdso_so_1_start[];
53 extern const char _binary_elf_vdso_so_1_end[];
54 extern char _binary_elf_vdso_so_1_size;
55
56 struct sysentvec elf64_freebsd_sysvec_la48 = {
57 .sv_size = SYS_MAXSYSCALL,
58 .sv_table = sysent,
59 .sv_fixup = __elfN(freebsd_fixup),
60 .sv_sendsig = sendsig,
61 .sv_sigcode = _binary_elf_vdso_so_1_start,
62 .sv_szsigcode = (int *)&_binary_elf_vdso_so_1_size,
63 .sv_sigcodeoff = VDSO_SIGCODE_OFFSET,
64 .sv_name = "FreeBSD ELF64",
65 .sv_coredump = __elfN(coredump),
66 .sv_elf_core_osabi = ELFOSABI_FREEBSD,
67 .sv_elf_core_abi_vendor = FREEBSD_ABI_VENDOR,
68 .sv_elf_core_prepare_notes = __elfN(prepare_notes),
69 .sv_minsigstksz = MINSIGSTKSZ,
70 .sv_minuser = VM_MIN_ADDRESS,
71 .sv_maxuser = VM_MAXUSER_ADDRESS_LA48,
72 .sv_usrstack = USRSTACK_LA48,
73 .sv_psstrings = PS_STRINGS_LA48,
74 .sv_psstringssz = sizeof(struct ps_strings),
75 .sv_stackprot = VM_PROT_ALL,
76 .sv_copyout_auxargs = __elfN(freebsd_copyout_auxargs),
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_ASLR | SV_LP64 | SV_SHP |
82 SV_TIMEKEEP | SV_RNG_SEED_VER | SV_DSO_SIG |
83 SV_SIGSYS,
84 .sv_set_syscall_retval = cpu_set_syscall_retval,
85 .sv_fetch_syscall_args = cpu_fetch_syscall_args,
86 .sv_syscallnames = syscallnames,
87 .sv_shared_page_base = SHAREDPAGE_LA48,
88 .sv_shared_page_len = PAGE_SIZE,
89 .sv_schedtail = NULL,
90 .sv_thread_detach = NULL,
91 .sv_trap = NULL,
92 .sv_onexec_old = exec_onexec_old,
93 .sv_onexit = exit_onexit,
94 .sv_set_fork_retval = x86_set_fork_retval,
95 .sv_regset_begin = SET_BEGIN(__elfN(regset)),
96 .sv_regset_end = SET_LIMIT(__elfN(regset)),
97 };
98
99 struct sysentvec elf64_freebsd_sysvec_la57 = {
100 .sv_size = SYS_MAXSYSCALL,
101 .sv_table = sysent,
102 .sv_fixup = __elfN(freebsd_fixup),
103 .sv_sendsig = sendsig,
104 .sv_sigcode = _binary_elf_vdso_so_1_start,
105 .sv_szsigcode = (int *)&_binary_elf_vdso_so_1_size,
106 .sv_sigcodeoff = VDSO_SIGCODE_OFFSET,
107 .sv_name = "FreeBSD ELF64",
108 .sv_coredump = __elfN(coredump),
109 .sv_elf_core_osabi = ELFOSABI_FREEBSD,
110 .sv_elf_core_abi_vendor = FREEBSD_ABI_VENDOR,
111 .sv_elf_core_prepare_notes = __elfN(prepare_notes),
112 .sv_minsigstksz = MINSIGSTKSZ,
113 .sv_minuser = VM_MIN_ADDRESS,
114 .sv_maxuser = VM_MAXUSER_ADDRESS_LA57,
115 .sv_usrstack = USRSTACK_LA57,
116 .sv_psstrings = PS_STRINGS_LA57,
117 .sv_psstringssz = sizeof(struct ps_strings),
118 .sv_stackprot = VM_PROT_ALL,
119 .sv_copyout_auxargs = __elfN(freebsd_copyout_auxargs),
120 .sv_copyout_strings = exec_copyout_strings,
121 .sv_setregs = exec_setregs,
122 .sv_fixlimit = NULL,
123 .sv_maxssiz = NULL,
124 .sv_flags = SV_ABI_FREEBSD | SV_ASLR | SV_LP64 | SV_SHP |
125 SV_TIMEKEEP | SV_RNG_SEED_VER | SV_DSO_SIG |
126 SV_SIGSYS,
127 .sv_set_syscall_retval = cpu_set_syscall_retval,
128 .sv_fetch_syscall_args = cpu_fetch_syscall_args,
129 .sv_syscallnames = syscallnames,
130 .sv_shared_page_base = SHAREDPAGE_LA57,
131 .sv_shared_page_len = PAGE_SIZE,
132 .sv_schedtail = NULL,
133 .sv_thread_detach = NULL,
134 .sv_trap = NULL,
135 .sv_onexec_old = exec_onexec_old,
136 .sv_onexit = exit_onexit,
137 .sv_set_fork_retval= x86_set_fork_retval,
138 .sv_regset_begin = SET_BEGIN(__elfN(regset)),
139 .sv_regset_end = SET_LIMIT(__elfN(regset)),
140 };
141
142 static void
amd64_init_sysvecs(void * arg)143 amd64_init_sysvecs(void *arg)
144 {
145 amd64_lower_shared_page(&elf64_freebsd_sysvec_la48);
146 if (la57) {
147 exec_sysvec_init(&elf64_freebsd_sysvec_la57);
148 exec_sysvec_init_secondary(&elf64_freebsd_sysvec_la57,
149 &elf64_freebsd_sysvec_la48);
150 } else {
151 exec_sysvec_init(&elf64_freebsd_sysvec_la48);
152 }
153 }
154 SYSINIT(elf64_sysvec, SI_SUB_EXEC, SI_ORDER_ANY, amd64_init_sysvecs, NULL);
155
156 void
amd64_lower_shared_page(struct sysentvec * sv)157 amd64_lower_shared_page(struct sysentvec *sv)
158 {
159 if (hw_lower_amd64_sharedpage != 0) {
160 sv->sv_maxuser -= PAGE_SIZE;
161 sv->sv_shared_page_base -= PAGE_SIZE;
162 sv->sv_usrstack -= PAGE_SIZE;
163 sv->sv_psstrings -= PAGE_SIZE;
164 }
165 }
166
167 static bool
freebsd_brand_info_la57_img_compat(const struct image_params * imgp,const int32_t * osrel __unused,const uint32_t * fctl0)168 freebsd_brand_info_la57_img_compat(const struct image_params *imgp,
169 const int32_t *osrel __unused, const uint32_t *fctl0)
170 {
171 if ((imgp->proc->p_md.md_flags & P_MD_LA57) != 0)
172 return (true);
173 if (fctl0 == NULL || (*fctl0 & NT_FREEBSD_FCTL_LA48) != 0)
174 return (false);
175 if ((imgp->proc->p_md.md_flags & P_MD_LA48) != 0)
176 return (false);
177 return (true);
178 }
179
180 static Elf64_Brandinfo freebsd_brand_info_la48 = {
181 .brand = ELFOSABI_FREEBSD,
182 .machine = EM_X86_64,
183 .compat_3_brand = "FreeBSD",
184 .interp_path = "/libexec/ld-elf.so.1",
185 .sysvec = &elf64_freebsd_sysvec_la48,
186 .interp_newpath = NULL,
187 .brand_note = &elf64_freebsd_brandnote,
188 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE,
189 };
190
191 static Elf64_Brandinfo freebsd_brand_info_la57 = {
192 .brand = ELFOSABI_FREEBSD,
193 .machine = EM_X86_64,
194 .compat_3_brand = "FreeBSD",
195 .interp_path = "/libexec/ld-elf.so.1",
196 .sysvec = &elf64_freebsd_sysvec_la57,
197 .interp_newpath = NULL,
198 .brand_note = &elf64_freebsd_brandnote,
199 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE,
200 .header_supported = freebsd_brand_info_la57_img_compat,
201 };
202
203 static void
sysinit_register_elf64_brand_entries(void * arg __unused)204 sysinit_register_elf64_brand_entries(void *arg __unused)
205 {
206 /*
207 * _57 must go first so it can either claim the image or hand
208 * it to _48.
209 */
210 if (la57)
211 elf64_insert_brand_entry(&freebsd_brand_info_la57);
212 elf64_insert_brand_entry(&freebsd_brand_info_la48);
213 }
214 SYSINIT(elf64, SI_SUB_EXEC, SI_ORDER_FIRST,
215 sysinit_register_elf64_brand_entries, NULL);
216
217 static Elf64_Brandinfo freebsd_brand_oinfo = {
218 .brand = ELFOSABI_FREEBSD,
219 .machine = EM_X86_64,
220 .compat_3_brand = "FreeBSD",
221 .interp_path = "/usr/libexec/ld-elf.so.1",
222 .sysvec = &elf64_freebsd_sysvec_la48,
223 .interp_newpath = NULL,
224 .brand_note = &elf64_freebsd_brandnote,
225 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
226 };
227
228 SYSINIT(oelf64, SI_SUB_EXEC, SI_ORDER_ANY,
229 (sysinit_cfunc_t)elf64_insert_brand_entry, &freebsd_brand_oinfo);
230
231 static Elf64_Brandinfo kfreebsd_brand_info = {
232 .brand = ELFOSABI_FREEBSD,
233 .machine = EM_X86_64,
234 .compat_3_brand = "FreeBSD",
235 .interp_path = "/lib/ld-kfreebsd-x86-64.so.1",
236 .sysvec = &elf64_freebsd_sysvec_la48,
237 .interp_newpath = NULL,
238 .brand_note = &elf64_kfreebsd_brandnote,
239 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE_MANDATORY
240 };
241
242 SYSINIT(kelf64, SI_SUB_EXEC, SI_ORDER_ANY,
243 (sysinit_cfunc_t)elf64_insert_brand_entry, &kfreebsd_brand_info);
244
245 void
elf64_dump_thread(struct thread * td,void * dst,size_t * off)246 elf64_dump_thread(struct thread *td, void *dst, size_t *off)
247 {
248 void *buf;
249 size_t len;
250
251 len = 0;
252 if (use_xsave) {
253 if (dst != NULL) {
254 fpugetregs(td);
255 len += elf64_populate_note(NT_X86_XSTATE,
256 get_pcb_user_save_td(td), dst,
257 cpu_max_ext_state_size, &buf);
258 *(uint64_t *)((char *)buf + X86_XSTATE_XCR0_OFFSET) =
259 xsave_mask;
260 } else
261 len += elf64_populate_note(NT_X86_XSTATE, NULL, NULL,
262 cpu_max_ext_state_size, NULL);
263 }
264 *off = len;
265 }
266
267 bool
elf_is_ifunc_reloc(Elf_Size r_info)268 elf_is_ifunc_reloc(Elf_Size r_info)
269 {
270
271 return (ELF_R_TYPE(r_info) == R_X86_64_IRELATIVE);
272 }
273
274 /* Process one elf relocation with addend. */
275 static int
elf_reloc_internal(linker_file_t lf,Elf_Addr relocbase,const void * data,int type,bool late_ifunc,elf_lookup_fn lookup)276 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data,
277 int type, bool late_ifunc, elf_lookup_fn lookup)
278 {
279 Elf64_Addr *where, val;
280 Elf32_Addr *where32, val32;
281 Elf_Addr addr;
282 Elf_Addr addend;
283 Elf_Size rtype, symidx;
284 const Elf_Rel *rel;
285 const Elf_Rela *rela;
286 int error;
287
288 switch (type) {
289 case ELF_RELOC_REL:
290 rel = (const Elf_Rel *)data;
291 where = (Elf_Addr *) (relocbase + rel->r_offset);
292 rtype = ELF_R_TYPE(rel->r_info);
293 symidx = ELF_R_SYM(rel->r_info);
294 /* Addend is 32 bit on 32 bit relocs */
295 switch (rtype) {
296 case R_X86_64_PC32:
297 case R_X86_64_32S:
298 case R_X86_64_PLT32:
299 addend = *(Elf32_Addr *)where;
300 break;
301 default:
302 addend = *where;
303 break;
304 }
305 break;
306 case ELF_RELOC_RELA:
307 rela = (const Elf_Rela *)data;
308 where = (Elf_Addr *) (relocbase + rela->r_offset);
309 addend = rela->r_addend;
310 rtype = ELF_R_TYPE(rela->r_info);
311 symidx = ELF_R_SYM(rela->r_info);
312 break;
313 default:
314 panic("unknown reloc type %d\n", type);
315 }
316
317 if (late_ifunc) {
318 KASSERT(type == ELF_RELOC_RELA,
319 ("Only RELA ifunc relocations are supported"));
320 if (rtype != R_X86_64_IRELATIVE)
321 return (0);
322 }
323
324 switch (rtype) {
325 case R_X86_64_NONE: /* none */
326 break;
327
328 case R_X86_64_64: /* S + A */
329 error = lookup(lf, symidx, 1, &addr);
330 val = addr + addend;
331 if (error != 0)
332 return (-1);
333 if (*where != val)
334 *where = val;
335 break;
336
337 case R_X86_64_PC32: /* S + A - P */
338 case R_X86_64_PLT32: /* L + A - P, L is PLT location for
339 the symbol, which we treat as S */
340 error = lookup(lf, symidx, 1, &addr);
341 where32 = (Elf32_Addr *)where;
342 val32 = (Elf32_Addr)(addr + addend - (Elf_Addr)where);
343 if (error != 0)
344 return (-1);
345 if (*where32 != val32)
346 *where32 = val32;
347 break;
348
349 case R_X86_64_32S: /* S + A sign extend */
350 error = lookup(lf, symidx, 1, &addr);
351 val32 = (Elf32_Addr)(addr + addend);
352 where32 = (Elf32_Addr *)where;
353 if (error != 0)
354 return (-1);
355 if (*where32 != val32)
356 *where32 = val32;
357 break;
358
359 case R_X86_64_COPY: /* none */
360 /*
361 * There shouldn't be copy relocations in kernel
362 * objects.
363 */
364 printf("kldload: unexpected R_COPY relocation, "
365 "symbol index %ld\n", symidx);
366 return (-1);
367
368 case R_X86_64_GLOB_DAT: /* S */
369 case R_X86_64_JMP_SLOT: /* XXX need addend + offset */
370 error = lookup(lf, symidx, 1, &addr);
371 if (error != 0)
372 return (-1);
373 if (*where != addr)
374 *where = addr;
375 break;
376
377 case R_X86_64_RELATIVE: /* B + A */
378 addr = elf_relocaddr(lf, relocbase + addend);
379 val = addr;
380 if (*where != val)
381 *where = val;
382 break;
383
384 case R_X86_64_IRELATIVE:
385 addr = relocbase + addend;
386 val = ((Elf64_Addr (*)(void))addr)();
387 if (*where != val)
388 *where = val;
389 break;
390
391 default:
392 printf("kldload: unexpected relocation type %ld, "
393 "symbol index %ld\n", rtype, symidx);
394 return (-1);
395 }
396 return (0);
397 }
398
399 int
elf_reloc(linker_file_t lf,Elf_Addr relocbase,const void * data,int type,elf_lookup_fn lookup)400 elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type,
401 elf_lookup_fn lookup)
402 {
403
404 return (elf_reloc_internal(lf, relocbase, data, type, false, lookup));
405 }
406
407 int
elf_reloc_local(linker_file_t lf,Elf_Addr relocbase,const void * data,int type,elf_lookup_fn lookup)408 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data,
409 int type, elf_lookup_fn lookup)
410 {
411
412 return (elf_reloc_internal(lf, relocbase, data, type, false, lookup));
413 }
414
415 int
elf_reloc_late(linker_file_t lf,Elf_Addr relocbase,const void * data,int type,elf_lookup_fn lookup)416 elf_reloc_late(linker_file_t lf, Elf_Addr relocbase, const void *data,
417 int type, elf_lookup_fn lookup)
418 {
419
420 return (elf_reloc_internal(lf, relocbase, data, type, true, lookup));
421 }
422
423 int
elf_cpu_load_file(linker_file_t lf __unused)424 elf_cpu_load_file(linker_file_t lf __unused)
425 {
426
427 return (0);
428 }
429
430 int
elf_cpu_unload_file(linker_file_t lf __unused)431 elf_cpu_unload_file(linker_file_t lf __unused)
432 {
433
434 return (0);
435 }
436
437 int
elf_cpu_parse_dynamic(caddr_t loadbase __unused,Elf_Dyn * dynamic __unused)438 elf_cpu_parse_dynamic(caddr_t loadbase __unused, Elf_Dyn *dynamic __unused)
439 {
440
441 return (0);
442 }
443