xref: /freebsd/sys/amd64/amd64/elf_machdep.c (revision 325151a3)
1 /*-
2  * Copyright 1996-1998 John D. Polstra.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  */
25 
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
28 
29 #include <sys/param.h>
30 #include <sys/kernel.h>
31 #include <sys/systm.h>
32 #include <sys/exec.h>
33 #include <sys/imgact.h>
34 #include <sys/linker.h>
35 #include <sys/proc.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 struct sysentvec elf64_freebsd_sysvec = {
51 	.sv_size	= SYS_MAXSYSCALL,
52 	.sv_table	= sysent,
53 	.sv_mask	= 0,
54 	.sv_sigsize	= 0,
55 	.sv_sigtbl	= NULL,
56 	.sv_errsize	= 0,
57 	.sv_errtbl	= NULL,
58 	.sv_transtrap	= NULL,
59 	.sv_fixup	= __elfN(freebsd_fixup),
60 	.sv_sendsig	= sendsig,
61 	.sv_sigcode	= sigcode,
62 	.sv_szsigcode	= &szsigcode,
63 	.sv_prepsyscall	= NULL,
64 	.sv_name	= "FreeBSD ELF64",
65 	.sv_coredump	= __elfN(coredump),
66 	.sv_imgact_try	= NULL,
67 	.sv_minsigstksz	= MINSIGSTKSZ,
68 	.sv_pagesize	= PAGE_SIZE,
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_LP64 | SV_SHP,
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 };
87 INIT_SYSENTVEC(elf64_sysvec, &elf64_freebsd_sysvec);
88 
89 static Elf64_Brandinfo freebsd_brand_info = {
90 	.brand		= ELFOSABI_FREEBSD,
91 	.machine	= EM_X86_64,
92 	.compat_3_brand	= "FreeBSD",
93 	.emul_path	= NULL,
94 	.interp_path	= "/libexec/ld-elf.so.1",
95 	.sysvec		= &elf64_freebsd_sysvec,
96 	.interp_newpath	= NULL,
97 	.brand_note	= &elf64_freebsd_brandnote,
98 	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
99 };
100 
101 SYSINIT(elf64, SI_SUB_EXEC, SI_ORDER_FIRST,
102 	(sysinit_cfunc_t) elf64_insert_brand_entry,
103 	&freebsd_brand_info);
104 
105 static Elf64_Brandinfo freebsd_brand_oinfo = {
106 	.brand		= ELFOSABI_FREEBSD,
107 	.machine	= EM_X86_64,
108 	.compat_3_brand	= "FreeBSD",
109 	.emul_path	= NULL,
110 	.interp_path	= "/usr/libexec/ld-elf.so.1",
111 	.sysvec		= &elf64_freebsd_sysvec,
112 	.interp_newpath	= NULL,
113 	.brand_note	= &elf64_freebsd_brandnote,
114 	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
115 };
116 
117 SYSINIT(oelf64, SI_SUB_EXEC, SI_ORDER_ANY,
118 	(sysinit_cfunc_t) elf64_insert_brand_entry,
119 	&freebsd_brand_oinfo);
120 
121 static Elf64_Brandinfo kfreebsd_brand_info = {
122 	.brand		= ELFOSABI_FREEBSD,
123 	.machine	= EM_X86_64,
124 	.compat_3_brand	= "FreeBSD",
125 	.emul_path	= NULL,
126 	.interp_path	= "/lib/ld-kfreebsd-x86-64.so.1",
127 	.sysvec		= &elf64_freebsd_sysvec,
128 	.interp_newpath	= NULL,
129 	.brand_note	= &elf64_kfreebsd_brandnote,
130 	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE_MANDATORY
131 };
132 
133 SYSINIT(kelf64, SI_SUB_EXEC, SI_ORDER_ANY,
134 	(sysinit_cfunc_t) elf64_insert_brand_entry,
135 	&kfreebsd_brand_info);
136 
137 void
138 elf64_dump_thread(struct thread *td, void *dst, size_t *off)
139 {
140 	void *buf;
141 	size_t len;
142 
143 	len = 0;
144 	if (use_xsave) {
145 		if (dst != NULL) {
146 			fpugetregs(td);
147 			len += elf64_populate_note(NT_X86_XSTATE,
148 			    get_pcb_user_save_td(td), dst,
149 			    cpu_max_ext_state_size, &buf);
150 			*(uint64_t *)((char *)buf + X86_XSTATE_XCR0_OFFSET) =
151 			    xsave_mask;
152 		} else
153 			len += elf64_populate_note(NT_X86_XSTATE, NULL, NULL,
154 			    cpu_max_ext_state_size, NULL);
155 	}
156 	*off = len;
157 }
158 
159 /* Process one elf relocation with addend. */
160 static int
161 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data,
162     int type, int local, elf_lookup_fn lookup)
163 {
164 	Elf64_Addr *where, val;
165 	Elf32_Addr *where32, val32;
166 	Elf_Addr addr;
167 	Elf_Addr addend;
168 	Elf_Size rtype, symidx;
169 	const Elf_Rel *rel;
170 	const Elf_Rela *rela;
171 	int error;
172 
173 	switch (type) {
174 	case ELF_RELOC_REL:
175 		rel = (const Elf_Rel *)data;
176 		where = (Elf_Addr *) (relocbase + rel->r_offset);
177 		rtype = ELF_R_TYPE(rel->r_info);
178 		symidx = ELF_R_SYM(rel->r_info);
179 		/* Addend is 32 bit on 32 bit relocs */
180 		switch (rtype) {
181 		case R_X86_64_PC32:
182 		case R_X86_64_32S:
183 			addend = *(Elf32_Addr *)where;
184 			break;
185 		default:
186 			addend = *where;
187 			break;
188 		}
189 		break;
190 	case ELF_RELOC_RELA:
191 		rela = (const Elf_Rela *)data;
192 		where = (Elf_Addr *) (relocbase + rela->r_offset);
193 		addend = rela->r_addend;
194 		rtype = ELF_R_TYPE(rela->r_info);
195 		symidx = ELF_R_SYM(rela->r_info);
196 		break;
197 	default:
198 		panic("unknown reloc type %d\n", type);
199 	}
200 
201 	switch (rtype) {
202 
203 		case R_X86_64_NONE:	/* none */
204 			break;
205 
206 		case R_X86_64_64:		/* S + A */
207 			error = lookup(lf, symidx, 1, &addr);
208 			val = addr + addend;
209 			if (error != 0)
210 				return -1;
211 			if (*where != val)
212 				*where = val;
213 			break;
214 
215 		case R_X86_64_PC32:	/* S + A - P */
216 			error = lookup(lf, symidx, 1, &addr);
217 			where32 = (Elf32_Addr *)where;
218 			val32 = (Elf32_Addr)(addr + addend - (Elf_Addr)where);
219 			if (error != 0)
220 				return -1;
221 			if (*where32 != val32)
222 				*where32 = val32;
223 			break;
224 
225 		case R_X86_64_32S:	/* S + A sign extend */
226 			error = lookup(lf, symidx, 1, &addr);
227 			val32 = (Elf32_Addr)(addr + addend);
228 			where32 = (Elf32_Addr *)where;
229 			if (error != 0)
230 				return -1;
231 			if (*where32 != val32)
232 				*where32 = val32;
233 			break;
234 
235 		case R_X86_64_COPY:	/* none */
236 			/*
237 			 * There shouldn't be copy relocations in kernel
238 			 * objects.
239 			 */
240 			printf("kldload: unexpected R_COPY relocation\n");
241 			return -1;
242 			break;
243 
244 		case R_X86_64_GLOB_DAT:	/* S */
245 		case R_X86_64_JMP_SLOT:	/* XXX need addend + offset */
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_X86_64_RELATIVE:	/* B + A */
254 			addr = relocbase + addend;
255 			val = addr;
256 			if (*where != val)
257 				*where = val;
258 			break;
259 
260 		default:
261 			printf("kldload: unexpected relocation type %ld\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, 0, lookup));
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, 1, lookup));
282 }
283 
284 int
285 elf_cpu_load_file(linker_file_t lf __unused)
286 {
287 
288 	return (0);
289 }
290 
291 int
292 elf_cpu_unload_file(linker_file_t lf __unused)
293 {
294 
295 	return (0);
296 }
297