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
52extern const char _binary_elf_vdso_so_1_start[];
53extern const char _binary_elf_vdso_so_1_end[];
54extern char _binary_elf_vdso_so_1_size;
55
56struct 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
99struct 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
142static void
143amd64_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}
154SYSINIT(elf64_sysvec, SI_SUB_EXEC, SI_ORDER_ANY, amd64_init_sysvecs, NULL);
155
156void
157amd64_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
167static bool
168freebsd_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
180static 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
191static 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
203static void
204sysinit_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}
214SYSINIT(elf64, SI_SUB_EXEC, SI_ORDER_FIRST,
215    sysinit_register_elf64_brand_entries, NULL);
216
217static 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
228SYSINIT(oelf64, SI_SUB_EXEC, SI_ORDER_ANY,
229    (sysinit_cfunc_t)elf64_insert_brand_entry, &freebsd_brand_oinfo);
230
231static 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
242SYSINIT(kelf64, SI_SUB_EXEC, SI_ORDER_ANY,
243    (sysinit_cfunc_t)elf64_insert_brand_entry, &kfreebsd_brand_info);
244
245void
246elf64_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
267bool
268elf_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. */
275static int
276elf_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
399int
400elf_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
407int
408elf_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
415int
416elf_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
423int
424elf_cpu_load_file(linker_file_t lf __unused)
425{
426
427	return (0);
428}
429
430int
431elf_cpu_unload_file(linker_file_t lf __unused)
432{
433
434	return (0);
435}
436
437int
438elf_cpu_parse_dynamic(caddr_t loadbase __unused, Elf_Dyn *dynamic __unused)
439{
440
441	return (0);
442}
443