elf_machdep.c revision 293490 
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: stable/10/sys/arm/arm/elf_machdep.c 293490 2016-01-09 14:53:08Z dchagin $");
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/sysent.h>
36#include <sys/imgact_elf.h>
37#include <sys/proc.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/md_var.h>
48
49struct sysentvec elf32_freebsd_sysvec = {
50	.sv_size	= SYS_MAXSYSCALL,
51	.sv_table	= sysent,
52	.sv_mask	= 0,
53	.sv_sigsize	= 0,
54	.sv_sigtbl	= NULL,
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_prepsyscall	= NULL,
63	.sv_name	= "FreeBSD ELF32",
64	.sv_coredump	= __elfN(coredump),
65	.sv_imgact_try	= NULL,
66	.sv_minsigstksz	= MINSIGSTKSZ,
67	.sv_pagesize	= PAGE_SIZE,
68	.sv_minuser	= VM_MIN_ADDRESS,
69	.sv_maxuser	= VM_MAXUSER_ADDRESS,
70	.sv_usrstack	= USRSTACK,
71	.sv_psstrings	= PS_STRINGS,
72	.sv_stackprot	= VM_PROT_ALL,
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_ILP32,
78	.sv_set_syscall_retval = cpu_set_syscall_retval,
79	.sv_fetch_syscall_args = cpu_fetch_syscall_args,
80	.sv_syscallnames = syscallnames,
81	.sv_schedtail	= NULL,
82	.sv_thread_detach = NULL,
83};
84
85static Elf32_Brandinfo freebsd_brand_info = {
86	.brand		= ELFOSABI_FREEBSD,
87	.machine	= EM_ARM,
88	.compat_3_brand	= "FreeBSD",
89	.emul_path	= NULL,
90	.interp_path	= "/libexec/ld-elf.so.1",
91	.sysvec		= &elf32_freebsd_sysvec,
92	.interp_newpath	= NULL,
93	.brand_note	= &elf32_freebsd_brandnote,
94	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
95};
96
97SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST,
98	(sysinit_cfunc_t) elf32_insert_brand_entry,
99	&freebsd_brand_info);
100
101static Elf32_Brandinfo freebsd_brand_oinfo = {
102	.brand		= ELFOSABI_FREEBSD,
103	.machine	= EM_ARM,
104	.compat_3_brand	= "FreeBSD",
105	.emul_path	= NULL,
106	.interp_path	= "/usr/libexec/ld-elf.so.1",
107	.sysvec		= &elf32_freebsd_sysvec,
108	.interp_newpath	= NULL,
109	.brand_note	= &elf32_freebsd_brandnote,
110	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
111};
112
113SYSINIT(oelf32, SI_SUB_EXEC, SI_ORDER_ANY,
114	(sysinit_cfunc_t) elf32_insert_brand_entry,
115	&freebsd_brand_oinfo);
116
117
118void
119elf32_dump_thread(struct thread *td __unused, void *dst __unused,
120    size_t *off __unused)
121{
122}
123
124
125/* Process one elf relocation with addend. */
126static int
127elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data,
128    int type, int local, elf_lookup_fn lookup)
129{
130	Elf_Addr *where;
131	Elf_Addr addr;
132	Elf_Addr addend;
133	Elf_Word rtype, symidx;
134	const Elf_Rel *rel;
135	const Elf_Rela *rela;
136	int error;
137
138	switch (type) {
139	case ELF_RELOC_REL:
140		rel = (const Elf_Rel *)data;
141		where = (Elf_Addr *) (relocbase + rel->r_offset);
142		addend = *where;
143		rtype = ELF_R_TYPE(rel->r_info);
144		symidx = ELF_R_SYM(rel->r_info);
145		break;
146	case ELF_RELOC_RELA:
147		rela = (const Elf_Rela *)data;
148		where = (Elf_Addr *) (relocbase + rela->r_offset);
149		addend = rela->r_addend;
150		rtype = ELF_R_TYPE(rela->r_info);
151		symidx = ELF_R_SYM(rela->r_info);
152		break;
153	default:
154		panic("unknown reloc type %d\n", type);
155	}
156
157	if (local) {
158		if (rtype == R_ARM_RELATIVE) {	/* A + B */
159			addr = elf_relocaddr(lf, relocbase + addend);
160			if (*where != addr)
161				*where = addr;
162		}
163		return (0);
164	}
165
166	switch (rtype) {
167
168		case R_ARM_NONE:	/* none */
169			break;
170
171		case R_ARM_ABS32:
172			error = lookup(lf, symidx, 1, &addr);
173			if (error != 0)
174				return -1;
175			*where += addr;
176			break;
177
178		case R_ARM_COPY:	/* none */
179			/*
180			 * There shouldn't be copy relocations in kernel
181			 * objects.
182			 */
183			printf("kldload: unexpected R_COPY relocation\n");
184			return -1;
185			break;
186
187		case R_ARM_JUMP_SLOT:
188			error = lookup(lf, symidx, 1, &addr);
189			if (error == 0) {
190				*where = addr;
191				return (0);
192			}
193			return (-1);
194		case R_ARM_RELATIVE:
195			break;
196
197		default:
198			printf("kldload: unexpected relocation type %d\n",
199			       rtype);
200			return -1;
201	}
202	return(0);
203}
204
205int
206elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type,
207    elf_lookup_fn lookup)
208{
209
210	return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup));
211}
212
213int
214elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data,
215    int type, elf_lookup_fn lookup)
216{
217
218	return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup));
219}
220
221int
222elf_cpu_load_file(linker_file_t lf __unused)
223{
224
225	/*
226	 * The pmap code does not do an icache sync upon establishing executable
227	 * mappings in the kernel pmap.  It's an optimization based on the fact
228	 * that kernel memory allocations always have EXECUTABLE protection even
229	 * when the memory isn't going to hold executable code.  The only time
230	 * kernel memory holding instructions does need a sync is after loading
231	 * a kernel module, and that's when this function gets called.  Normal
232	 * data cache maintenance has already been done by the IO code, and TLB
233	 * maintenance has been done by the pmap code, so all we have to do here
234	 * is invalidate the instruction cache (which also invalidates the
235	 * branch predictor cache on platforms that have one).
236	 */
237	cpu_icache_sync_all();
238	return (0);
239}
240
241int
242elf_cpu_unload_file(linker_file_t lf __unused)
243{
244
245	return (0);
246}
247