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/reg.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 #include <machine/stack.h>
49 #ifdef VFP
50 #include <machine/vfp.h>
51 #endif
52
53 #include "opt_ddb.h" /* for OPT_DDB */
54 #include "opt_global.h" /* for OPT_KDTRACE_HOOKS */
55 #include "opt_stack.h" /* for OPT_STACK */
56
57 static bool elf32_arm_abi_supported(const struct image_params *,
58 const int32_t *, const uint32_t *);
59
60 u_long elf_hwcap;
61 u_long elf_hwcap2;
62
63 struct sysentvec elf32_freebsd_sysvec = {
64 .sv_size = SYS_MAXSYSCALL,
65 .sv_table = sysent,
66 .sv_fixup = __elfN(freebsd_fixup),
67 .sv_sendsig = sendsig,
68 .sv_sigcode = sigcode,
69 .sv_szsigcode = &szsigcode,
70 .sv_name = "FreeBSD ELF32",
71 .sv_coredump = __elfN(coredump),
72 .sv_elf_core_osabi = ELFOSABI_FREEBSD,
73 .sv_elf_core_abi_vendor = FREEBSD_ABI_VENDOR,
74 .sv_elf_core_prepare_notes = __elfN(prepare_notes),
75 .sv_minsigstksz = MINSIGSTKSZ,
76 .sv_minuser = VM_MIN_ADDRESS,
77 .sv_maxuser = VM_MAXUSER_ADDRESS,
78 .sv_usrstack = USRSTACK,
79 .sv_psstrings = PS_STRINGS,
80 .sv_psstringssz = sizeof(struct ps_strings),
81 .sv_stackprot = VM_PROT_ALL,
82 .sv_copyout_auxargs = __elfN(freebsd_copyout_auxargs),
83 .sv_copyout_strings = exec_copyout_strings,
84 .sv_setregs = exec_setregs,
85 .sv_fixlimit = NULL,
86 .sv_maxssiz = NULL,
87 .sv_flags =
88 SV_ASLR | SV_SHP | SV_TIMEKEEP | SV_RNG_SEED_VER |
89 SV_ABI_FREEBSD | SV_ILP32 | SV_SIGSYS,
90 .sv_set_syscall_retval = cpu_set_syscall_retval,
91 .sv_fetch_syscall_args = cpu_fetch_syscall_args,
92 .sv_syscallnames = syscallnames,
93 .sv_shared_page_base = SHAREDPAGE,
94 .sv_shared_page_len = PAGE_SIZE,
95 .sv_schedtail = NULL,
96 .sv_thread_detach = NULL,
97 .sv_trap = NULL,
98 .sv_hwcap = &elf_hwcap,
99 .sv_hwcap2 = &elf_hwcap2,
100 .sv_onexec_old = exec_onexec_old,
101 .sv_onexit = exit_onexit,
102 .sv_regset_begin = SET_BEGIN(__elfN(regset)),
103 .sv_regset_end = SET_LIMIT(__elfN(regset)),
104 };
105 INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec);
106
107 static Elf32_Brandinfo freebsd_brand_info = {
108 .brand = ELFOSABI_FREEBSD,
109 .machine = EM_ARM,
110 .compat_3_brand = "FreeBSD",
111 .interp_path = "/libexec/ld-elf.so.1",
112 .sysvec = &elf32_freebsd_sysvec,
113 .interp_newpath = NULL,
114 .brand_note = &elf32_freebsd_brandnote,
115 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE,
116 .header_supported= elf32_arm_abi_supported,
117 };
118
119 SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST,
120 (sysinit_cfunc_t) elf32_insert_brand_entry,
121 &freebsd_brand_info);
122
123 static bool
elf32_arm_abi_supported(const struct image_params * imgp,const int32_t * osrel __unused,const uint32_t * fctl0 __unused)124 elf32_arm_abi_supported(const struct image_params *imgp,
125 const int32_t *osrel __unused, const uint32_t *fctl0 __unused)
126 {
127 const Elf_Ehdr *hdr = (const Elf_Ehdr *)imgp->image_header;
128
129 /*
130 * When configured for EABI, FreeBSD supports EABI vesions 4 and 5.
131 */
132 if (EF_ARM_EABI_VERSION(hdr->e_flags) < EF_ARM_EABI_FREEBSD_MIN) {
133 if (bootverbose)
134 uprintf("Attempting to execute non EABI binary (rev %d) image %s",
135 EF_ARM_EABI_VERSION(hdr->e_flags), imgp->args->fname);
136 return (false);
137 }
138 return (true);
139 }
140
141 void
elf32_dump_thread(struct thread * td __unused,void * dst __unused,size_t * off __unused)142 elf32_dump_thread(struct thread *td __unused, void *dst __unused,
143 size_t *off __unused)
144 {
145 }
146
147 bool
elf_is_ifunc_reloc(Elf_Size r_info __unused)148 elf_is_ifunc_reloc(Elf_Size r_info __unused)
149 {
150
151 return (false);
152 }
153
154 /*
155 * It is possible for the compiler to emit relocations for unaligned data.
156 * We handle this situation with these inlines.
157 */
158 #define RELOC_ALIGNED_P(x) \
159 (((uintptr_t)(x) & (sizeof(void *) - 1)) == 0)
160
161 static __inline Elf_Addr
load_ptr(Elf_Addr * where)162 load_ptr(Elf_Addr *where)
163 {
164 Elf_Addr res;
165
166 if (RELOC_ALIGNED_P(where))
167 return *where;
168 memcpy(&res, where, sizeof(res));
169 return (res);
170 }
171
172 static __inline void
store_ptr(Elf_Addr * where,Elf_Addr val)173 store_ptr(Elf_Addr *where, Elf_Addr val)
174 {
175 if (RELOC_ALIGNED_P(where))
176 *where = val;
177 else
178 memcpy(where, &val, sizeof(val));
179 }
180 #undef RELOC_ALIGNED_P
181
182 /* Process one elf relocation with addend. */
183 static int
elf_reloc_internal(linker_file_t lf,Elf_Addr relocbase,const void * data,int type,int local,elf_lookup_fn lookup)184 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data,
185 int type, int local, elf_lookup_fn lookup)
186 {
187 Elf_Addr *where;
188 Elf_Addr addr;
189 Elf_Addr addend;
190 Elf_Word rtype, symidx;
191 const Elf_Rel *rel;
192 const Elf_Rela *rela;
193 int error;
194
195 switch (type) {
196 case ELF_RELOC_REL:
197 rel = (const Elf_Rel *)data;
198 where = (Elf_Addr *) (relocbase + rel->r_offset);
199 addend = load_ptr(where);
200 rtype = ELF_R_TYPE(rel->r_info);
201 symidx = ELF_R_SYM(rel->r_info);
202 break;
203 case ELF_RELOC_RELA:
204 rela = (const Elf_Rela *)data;
205 where = (Elf_Addr *) (relocbase + rela->r_offset);
206 addend = rela->r_addend;
207 rtype = ELF_R_TYPE(rela->r_info);
208 symidx = ELF_R_SYM(rela->r_info);
209 break;
210 default:
211 panic("unknown reloc type %d\n", type);
212 }
213
214 if (local) {
215 if (rtype == R_ARM_RELATIVE) { /* A + B */
216 addr = elf_relocaddr(lf, relocbase + addend);
217 if (load_ptr(where) != addr)
218 store_ptr(where, addr);
219 }
220 return (0);
221 }
222
223 switch (rtype) {
224 case R_ARM_NONE: /* none */
225 break;
226
227 case R_ARM_ABS32:
228 error = lookup(lf, symidx, 1, &addr);
229 if (error != 0)
230 return (-1);
231 store_ptr(where, addr + load_ptr(where));
232 break;
233
234 case R_ARM_COPY: /* none */
235 /*
236 * There shouldn't be copy relocations in kernel
237 * objects.
238 */
239 printf("kldload: unexpected R_COPY relocation, "
240 "symbol index %d\n", symidx);
241 return (-1);
242 break;
243
244 case R_ARM_JUMP_SLOT:
245 error = lookup(lf, symidx, 1, &addr);
246 if (error == 0) {
247 store_ptr(where, addr);
248 return (0);
249 }
250 return (-1);
251 case R_ARM_RELATIVE:
252 break;
253
254 default:
255 printf("kldload: unexpected relocation type %d, "
256 "symbol index %d\n", rtype, symidx);
257 return (-1);
258 }
259 return(0);
260 }
261
262 int
elf_reloc(linker_file_t lf,Elf_Addr relocbase,const void * data,int type,elf_lookup_fn lookup)263 elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type,
264 elf_lookup_fn lookup)
265 {
266
267 return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup));
268 }
269
270 int
elf_reloc_local(linker_file_t lf,Elf_Addr relocbase,const void * data,int type,elf_lookup_fn lookup)271 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data,
272 int type, elf_lookup_fn lookup)
273 {
274
275 return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup));
276 }
277
278 int
elf_cpu_load_file(linker_file_t lf)279 elf_cpu_load_file(linker_file_t lf)
280 {
281
282 /*
283 * The pmap code does not do an icache sync upon establishing executable
284 * mappings in the kernel pmap. It's an optimization based on the fact
285 * that kernel memory allocations always have EXECUTABLE protection even
286 * when the memory isn't going to hold executable code. The only time
287 * kernel memory holding instructions does need a sync is after loading
288 * a kernel module, and that's when this function gets called.
289 *
290 * This syncs data and instruction caches after loading a module. We
291 * don't worry about the kernel itself (lf->id is 1) as locore.S did
292 * that on entry. Even if data cache maintenance was done by IO code,
293 * the relocation fixup process creates dirty cache entries that we must
294 * write back before doing icache sync. The instruction cache sync also
295 * invalidates the branch predictor cache on platforms that have one.
296 */
297 if (lf->id == 1)
298 return (0);
299 dcache_wb_pou((vm_offset_t)lf->address, (vm_size_t)lf->size);
300 icache_inv_all();
301
302 #if defined(DDB) || defined(KDTRACE_HOOKS) || defined(STACK)
303 /*
304 * Inform the stack(9) code of the new module, so it can acquire its
305 * per-module unwind data.
306 */
307 unwind_module_loaded(lf);
308 #endif
309
310 return (0);
311 }
312
313 int
elf_cpu_parse_dynamic(caddr_t loadbase __unused,Elf_Dyn * dynamic __unused)314 elf_cpu_parse_dynamic(caddr_t loadbase __unused, Elf_Dyn *dynamic __unused)
315 {
316
317 return (0);
318 }
319
320 int
elf_cpu_unload_file(linker_file_t lf)321 elf_cpu_unload_file(linker_file_t lf)
322 {
323
324 #if defined(DDB) || defined(KDTRACE_HOOKS) || defined(STACK)
325 /* Inform the stack(9) code that this module is gone. */
326 unwind_module_unloaded(lf);
327 #endif
328 return (0);
329 }
330