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 <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/proc.h>
38#include <sys/sysent.h>
39#include <sys/imgact_elf.h>
40#include <sys/syscall.h>
41#include <sys/signalvar.h>
42#include <sys/vnode.h>
43
44#include <vm/vm.h>
45#include <vm/pmap.h>
46#include <vm/vm_param.h>
47
48#include <machine/elf.h>
49#include <machine/fpu.h>
50#include <machine/md_var.h>
51
52struct sysentvec elf64_freebsd_sysvec = {
53	.sv_size	= SYS_MAXSYSCALL,
54	.sv_table	= sysent,
55	.sv_errsize	= 0,
56	.sv_errtbl	= NULL,
57	.sv_transtrap	= NULL,
58	.sv_fixup	= __elfN(freebsd_fixup),
59	.sv_sendsig	= sendsig,
60	.sv_sigcode	= sigcode,
61	.sv_szsigcode	= &szsigcode,
62	.sv_name	= "FreeBSD ELF64",
63	.sv_coredump	= __elfN(coredump),
64	.sv_imgact_try	= NULL,
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_stackprot	= VM_PROT_ALL,
71	.sv_copyout_auxargs = __elfN(freebsd_copyout_auxargs),
72	.sv_copyout_strings	= exec_copyout_strings,
73	.sv_setregs	= exec_setregs,
74	.sv_fixlimit	= NULL,
75	.sv_maxssiz	= NULL,
76	.sv_flags	= SV_ABI_FREEBSD | SV_ASLR | SV_LP64 | SV_SHP |
77			    SV_TIMEKEEP,
78	.sv_set_syscall_retval = cpu_set_syscall_retval,
79	.sv_fetch_syscall_args = cpu_fetch_syscall_args,
80	.sv_syscallnames = syscallnames,
81	.sv_shared_page_base = SHAREDPAGE,
82	.sv_shared_page_len = PAGE_SIZE,
83	.sv_schedtail	= NULL,
84	.sv_thread_detach = NULL,
85	.sv_trap	= NULL,
86	.sv_stackgap	= elf64_stackgap,
87};
88INIT_SYSENTVEC(elf64_sysvec, &elf64_freebsd_sysvec);
89
90void
91amd64_lower_shared_page(struct sysentvec *sv)
92{
93	if (hw_lower_amd64_sharedpage != 0) {
94		sv->sv_maxuser -= PAGE_SIZE;
95		sv->sv_shared_page_base -= PAGE_SIZE;
96		sv->sv_usrstack -= PAGE_SIZE;
97		sv->sv_psstrings -= PAGE_SIZE;
98	}
99}
100
101/*
102 * Do this fixup before INIT_SYSENTVEC (SI_ORDER_ANY) because the latter
103 * uses the value of sv_shared_page_base.
104 */
105SYSINIT(elf64_sysvec_fixup, SI_SUB_EXEC, SI_ORDER_FIRST,
106	(sysinit_cfunc_t) amd64_lower_shared_page,
107	&elf64_freebsd_sysvec);
108
109static Elf64_Brandinfo freebsd_brand_info = {
110	.brand		= ELFOSABI_FREEBSD,
111	.machine	= EM_X86_64,
112	.compat_3_brand	= "FreeBSD",
113	.emul_path	= NULL,
114	.interp_path	= "/libexec/ld-elf.so.1",
115	.sysvec		= &elf64_freebsd_sysvec,
116	.interp_newpath	= NULL,
117	.brand_note	= &elf64_freebsd_brandnote,
118	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
119};
120
121SYSINIT(elf64, SI_SUB_EXEC, SI_ORDER_FIRST,
122	(sysinit_cfunc_t) elf64_insert_brand_entry,
123	&freebsd_brand_info);
124
125static Elf64_Brandinfo freebsd_brand_oinfo = {
126	.brand		= ELFOSABI_FREEBSD,
127	.machine	= EM_X86_64,
128	.compat_3_brand	= "FreeBSD",
129	.emul_path	= NULL,
130	.interp_path	= "/usr/libexec/ld-elf.so.1",
131	.sysvec		= &elf64_freebsd_sysvec,
132	.interp_newpath	= NULL,
133	.brand_note	= &elf64_freebsd_brandnote,
134	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
135};
136
137SYSINIT(oelf64, SI_SUB_EXEC, SI_ORDER_ANY,
138	(sysinit_cfunc_t) elf64_insert_brand_entry,
139	&freebsd_brand_oinfo);
140
141static Elf64_Brandinfo kfreebsd_brand_info = {
142	.brand		= ELFOSABI_FREEBSD,
143	.machine	= EM_X86_64,
144	.compat_3_brand	= "FreeBSD",
145	.emul_path	= NULL,
146	.interp_path	= "/lib/ld-kfreebsd-x86-64.so.1",
147	.sysvec		= &elf64_freebsd_sysvec,
148	.interp_newpath	= NULL,
149	.brand_note	= &elf64_kfreebsd_brandnote,
150	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE_MANDATORY
151};
152
153SYSINIT(kelf64, SI_SUB_EXEC, SI_ORDER_ANY,
154	(sysinit_cfunc_t) elf64_insert_brand_entry,
155	&kfreebsd_brand_info);
156
157void
158elf64_dump_thread(struct thread *td, void *dst, size_t *off)
159{
160	void *buf;
161	size_t len;
162
163	len = 0;
164	if (use_xsave) {
165		if (dst != NULL) {
166			fpugetregs(td);
167			len += elf64_populate_note(NT_X86_XSTATE,
168			    get_pcb_user_save_td(td), dst,
169			    cpu_max_ext_state_size, &buf);
170			*(uint64_t *)((char *)buf + X86_XSTATE_XCR0_OFFSET) =
171			    xsave_mask;
172		} else
173			len += elf64_populate_note(NT_X86_XSTATE, NULL, NULL,
174			    cpu_max_ext_state_size, NULL);
175	}
176	*off = len;
177}
178
179bool
180elf_is_ifunc_reloc(Elf_Size r_info)
181{
182
183	return (ELF_R_TYPE(r_info) == R_X86_64_IRELATIVE);
184}
185
186/* Process one elf relocation with addend. */
187static int
188elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data,
189    int type, elf_lookup_fn lookup)
190{
191	Elf64_Addr *where, val;
192	Elf32_Addr *where32, val32;
193	Elf_Addr addr;
194	Elf_Addr addend;
195	Elf_Size rtype, symidx;
196	const Elf_Rel *rel;
197	const Elf_Rela *rela;
198	int error;
199
200	switch (type) {
201	case ELF_RELOC_REL:
202		rel = (const Elf_Rel *)data;
203		where = (Elf_Addr *) (relocbase + rel->r_offset);
204		rtype = ELF_R_TYPE(rel->r_info);
205		symidx = ELF_R_SYM(rel->r_info);
206		/* Addend is 32 bit on 32 bit relocs */
207		switch (rtype) {
208		case R_X86_64_PC32:
209		case R_X86_64_32S:
210		case R_X86_64_PLT32:
211			addend = *(Elf32_Addr *)where;
212			break;
213		default:
214			addend = *where;
215			break;
216		}
217		break;
218	case ELF_RELOC_RELA:
219		rela = (const Elf_Rela *)data;
220		where = (Elf_Addr *) (relocbase + rela->r_offset);
221		addend = rela->r_addend;
222		rtype = ELF_R_TYPE(rela->r_info);
223		symidx = ELF_R_SYM(rela->r_info);
224		break;
225	default:
226		panic("unknown reloc type %d\n", type);
227	}
228
229	switch (rtype) {
230		case R_X86_64_NONE:	/* none */
231			break;
232
233		case R_X86_64_64:		/* S + A */
234			error = lookup(lf, symidx, 1, &addr);
235			val = addr + addend;
236			if (error != 0)
237				return -1;
238			if (*where != val)
239				*where = val;
240			break;
241
242		case R_X86_64_PC32:	/* S + A - P */
243		case R_X86_64_PLT32:	/* L + A - P, L is PLT location for
244					   the symbol, which we treat as S */
245			error = lookup(lf, symidx, 1, &addr);
246			where32 = (Elf32_Addr *)where;
247			val32 = (Elf32_Addr)(addr + addend - (Elf_Addr)where);
248			if (error != 0)
249				return -1;
250			if (*where32 != val32)
251				*where32 = val32;
252			break;
253
254		case R_X86_64_32S:	/* S + A sign extend */
255			error = lookup(lf, symidx, 1, &addr);
256			val32 = (Elf32_Addr)(addr + addend);
257			where32 = (Elf32_Addr *)where;
258			if (error != 0)
259				return -1;
260			if (*where32 != val32)
261				*where32 = val32;
262			break;
263
264		case R_X86_64_COPY:	/* none */
265			/*
266			 * There shouldn't be copy relocations in kernel
267			 * objects.
268			 */
269			printf("kldload: unexpected R_COPY relocation\n");
270			return (-1);
271
272		case R_X86_64_GLOB_DAT:	/* S */
273		case R_X86_64_JMP_SLOT:	/* XXX need addend + offset */
274			error = lookup(lf, symidx, 1, &addr);
275			if (error != 0)
276				return -1;
277			if (*where != addr)
278				*where = addr;
279			break;
280
281		case R_X86_64_RELATIVE:	/* B + A */
282			addr = elf_relocaddr(lf, relocbase + addend);
283			val = addr;
284			if (*where != val)
285				*where = val;
286			break;
287
288		case R_X86_64_IRELATIVE:
289			addr = relocbase + addend;
290			val = ((Elf64_Addr (*)(void))addr)();
291			if (*where != val)
292				*where = val;
293			break;
294
295		default:
296			printf("kldload: unexpected relocation type %ld\n",
297			       rtype);
298			return (-1);
299	}
300	return (0);
301}
302
303int
304elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type,
305    elf_lookup_fn lookup)
306{
307
308	return (elf_reloc_internal(lf, relocbase, data, type, lookup));
309}
310
311int
312elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data,
313    int type, elf_lookup_fn lookup)
314{
315
316	return (elf_reloc_internal(lf, relocbase, data, type, lookup));
317}
318
319int
320elf_cpu_load_file(linker_file_t lf __unused)
321{
322
323	return (0);
324}
325
326int
327elf_cpu_unload_file(linker_file_t lf __unused)
328{
329
330	return (0);
331}
332
333int
334elf_cpu_parse_dynamic(linker_file_t lf __unused, Elf_Dyn *dynamic __unused)
335{
336
337	return (0);
338}
339