1 /*-
2 * Copyright (c) 2014, 2015 The FreeBSD Foundation.
3 * Copyright (c) 2014 Andrew Turner.
4 * All rights reserved.
5 *
6 * This software was developed by Andrew Turner under
7 * sponsorship from the FreeBSD Foundation.
8 *
9 * Portions of this software were developed by Konstantin Belousov
10 * under sponsorship from the FreeBSD Foundation.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #include <sys/param.h>
35 #include <sys/kernel.h>
36 #include <sys/systm.h>
37 #include <sys/exec.h>
38 #include <sys/imgact.h>
39 #include <sys/linker.h>
40 #include <sys/proc.h>
41 #include <sys/reg.h>
42 #include <sys/sysent.h>
43 #include <sys/imgact_elf.h>
44 #include <sys/syscall.h>
45 #include <sys/signalvar.h>
46 #include <sys/vnode.h>
47
48 #include <vm/vm.h>
49 #include <vm/pmap.h>
50 #include <vm/vm_param.h>
51 #include <vm/vm_map.h>
52
53 #include <machine/elf.h>
54 #include <machine/md_var.h>
55
56 #include "linker_if.h"
57
58 u_long __read_frequently elf_hwcap;
59 u_long __read_frequently elf_hwcap2;
60 u_long __read_frequently elf_hwcap3;
61 u_long __read_frequently elf_hwcap4;
62 /* TODO: Move to a better location */
63 u_long __read_frequently linux_elf_hwcap;
64 u_long __read_frequently linux_elf_hwcap2;
65 u_long __read_frequently linux_elf_hwcap3;
66 u_long __read_frequently linux_elf_hwcap4;
67
68 struct arm64_addr_mask elf64_addr_mask = {
69 .code = TBI_ADDR_MASK,
70 .data = TBI_ADDR_MASK,
71 };
72 #ifdef COMPAT_FREEBSD14
73 struct arm64_addr_mask elf64_addr_mask_14;
74 #endif
75
76 static void arm64_exec_protect(struct image_params *, int);
77
78 static struct sysentvec elf64_freebsd_sysvec = {
79 .sv_size = SYS_MAXSYSCALL,
80 .sv_table = sysent,
81 .sv_fixup = __elfN(freebsd_fixup),
82 .sv_sendsig = sendsig,
83 .sv_sigcode = sigcode,
84 .sv_szsigcode = &szsigcode,
85 .sv_name = "FreeBSD ELF64",
86 .sv_coredump = __elfN(coredump),
87 .sv_elf_core_osabi = ELFOSABI_FREEBSD,
88 .sv_elf_core_abi_vendor = FREEBSD_ABI_VENDOR,
89 .sv_elf_core_prepare_notes = __elfN(prepare_notes),
90 .sv_minsigstksz = MINSIGSTKSZ,
91 .sv_minuser = VM_MIN_ADDRESS,
92 .sv_maxuser = VM_MAXUSER_ADDRESS,
93 .sv_usrstack = USRSTACK,
94 .sv_psstrings = PS_STRINGS,
95 .sv_psstringssz = sizeof(struct ps_strings),
96 .sv_stackprot = VM_PROT_READ | VM_PROT_WRITE,
97 .sv_copyout_auxargs = __elfN(freebsd_copyout_auxargs),
98 .sv_copyout_strings = exec_copyout_strings,
99 .sv_setregs = exec_setregs,
100 .sv_fixlimit = NULL,
101 .sv_maxssiz = NULL,
102 .sv_flags = SV_SHP | SV_TIMEKEEP | SV_ABI_FREEBSD | SV_LP64 |
103 SV_ASLR | SV_RNG_SEED_VER | SV_SIGSYS,
104 .sv_set_syscall_retval = cpu_set_syscall_retval,
105 .sv_fetch_syscall_args = cpu_fetch_syscall_args,
106 .sv_syscallnames = syscallnames,
107 .sv_shared_page_base = SHAREDPAGE,
108 .sv_shared_page_len = PAGE_SIZE,
109 .sv_schedtail = NULL,
110 .sv_thread_detach = NULL,
111 .sv_trap = NULL,
112 .sv_hwcap = &elf_hwcap,
113 .sv_hwcap2 = &elf_hwcap2,
114 .sv_hwcap3 = &elf_hwcap3,
115 .sv_hwcap4 = &elf_hwcap4,
116 .sv_onexec_old = exec_onexec_old,
117 .sv_protect = arm64_exec_protect,
118 .sv_onexit = exit_onexit,
119 .sv_regset_begin = SET_BEGIN(__elfN(regset)),
120 .sv_regset_end = SET_LIMIT(__elfN(regset)),
121 };
122 INIT_SYSENTVEC(elf64_sysvec, &elf64_freebsd_sysvec);
123
124 static Elf64_Brandinfo freebsd_brand_info = {
125 .brand = ELFOSABI_FREEBSD,
126 .machine = EM_AARCH64,
127 .compat_3_brand = "FreeBSD",
128 .interp_path = "/libexec/ld-elf.so.1",
129 .sysvec = &elf64_freebsd_sysvec,
130 .interp_newpath = NULL,
131 .brand_note = &elf64_freebsd_brandnote,
132 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
133 };
134
135 SYSINIT(elf64, SI_SUB_EXEC, SI_ORDER_FIRST,
136 (sysinit_cfunc_t)elf64_insert_brand_entry, &freebsd_brand_info);
137
138 static bool
get_arm64_addr_mask(struct regset * rs,struct thread * td,void * buf,size_t * sizep)139 get_arm64_addr_mask(struct regset *rs, struct thread *td, void *buf,
140 size_t *sizep)
141 {
142 if (buf != NULL) {
143 KASSERT(*sizep == sizeof(elf64_addr_mask),
144 ("%s: invalid size", __func__));
145 #ifdef COMPAT_FREEBSD14
146 /* running an old binary use the old address mask */
147 if (td->td_proc->p_osrel < TBI_VERSION)
148 memcpy(buf, &elf64_addr_mask_14,
149 sizeof(elf64_addr_mask_14));
150 else
151 #endif
152 memcpy(buf, &elf64_addr_mask, sizeof(elf64_addr_mask));
153 }
154 *sizep = sizeof(elf64_addr_mask);
155
156 return (true);
157 }
158
159 static struct regset regset_arm64_addr_mask = {
160 .note = NT_ARM_ADDR_MASK,
161 .size = sizeof(struct arm64_addr_mask),
162 .get = get_arm64_addr_mask,
163 };
164 ELF_REGSET(regset_arm64_addr_mask);
165
166 void
elf64_dump_thread(struct thread * td __unused,void * dst __unused,size_t * off __unused)167 elf64_dump_thread(struct thread *td __unused, void *dst __unused,
168 size_t *off __unused)
169 {
170 }
171
172 bool
elf_is_ifunc_reloc(Elf_Size r_info __unused)173 elf_is_ifunc_reloc(Elf_Size r_info __unused)
174 {
175
176 return (ELF_R_TYPE(r_info) == R_AARCH64_IRELATIVE);
177 }
178
179 static int
reloc_instr_imm(Elf32_Addr * where,Elf_Addr val,u_int msb,u_int lsb)180 reloc_instr_imm(Elf32_Addr *where, Elf_Addr val, u_int msb, u_int lsb)
181 {
182
183 /* Check bounds: upper bits must be all ones or all zeros. */
184 if ((uint64_t)((int64_t)val >> (msb + 1)) + 1 > 1)
185 return (-1);
186 val >>= lsb;
187 val &= (1 << (msb - lsb + 1)) - 1;
188 *where |= (Elf32_Addr)val;
189 return (0);
190 }
191
192 /*
193 * Process a relocation. Support for some static relocations is required
194 * in order for the -zifunc-noplt optimization to work.
195 */
196 static int
elf_reloc_internal(linker_file_t lf,Elf_Addr relocbase,const void * data,int type,int flags,elf_lookup_fn lookup)197 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data,
198 int type, int flags, elf_lookup_fn lookup)
199 {
200 #define ARM64_ELF_RELOC_LOCAL (1 << 0)
201 #define ARM64_ELF_RELOC_LATE_IFUNC (1 << 1)
202 Elf_Addr *where, addr, addend, val;
203 Elf_Word rtype, symidx;
204 const Elf_Rel *rel;
205 const Elf_Rela *rela;
206 int error;
207
208 switch (type) {
209 case ELF_RELOC_REL:
210 rel = (const Elf_Rel *)data;
211 where = (Elf_Addr *) (relocbase + rel->r_offset);
212 addend = *where;
213 rtype = ELF_R_TYPE(rel->r_info);
214 symidx = ELF_R_SYM(rel->r_info);
215 break;
216 case ELF_RELOC_RELA:
217 rela = (const Elf_Rela *)data;
218 where = (Elf_Addr *) (relocbase + rela->r_offset);
219 addend = rela->r_addend;
220 rtype = ELF_R_TYPE(rela->r_info);
221 symidx = ELF_R_SYM(rela->r_info);
222 break;
223 default:
224 panic("unknown reloc type %d\n", type);
225 }
226
227 if ((flags & ARM64_ELF_RELOC_LATE_IFUNC) != 0) {
228 KASSERT(type == ELF_RELOC_RELA,
229 ("Only RELA ifunc relocations are supported"));
230 if (rtype != R_AARCH64_IRELATIVE)
231 return (0);
232 }
233
234 if ((flags & ARM64_ELF_RELOC_LOCAL) != 0) {
235 if (rtype == R_AARCH64_RELATIVE)
236 *where = elf_relocaddr(lf, relocbase + addend);
237 return (0);
238 }
239
240 error = 0;
241 switch (rtype) {
242 case R_AARCH64_NONE:
243 case R_AARCH64_RELATIVE:
244 break;
245 case R_AARCH64_TSTBR14:
246 error = lookup(lf, symidx, 1, &addr);
247 if (error != 0)
248 return (-1);
249 error = reloc_instr_imm((Elf32_Addr *)where,
250 addr + addend - (Elf_Addr)where, 15, 2);
251 break;
252 case R_AARCH64_CONDBR19:
253 error = lookup(lf, symidx, 1, &addr);
254 if (error != 0)
255 return (-1);
256 error = reloc_instr_imm((Elf32_Addr *)where,
257 addr + addend - (Elf_Addr)where, 20, 2);
258 break;
259 case R_AARCH64_JUMP26:
260 case R_AARCH64_CALL26:
261 error = lookup(lf, symidx, 1, &addr);
262 if (error != 0)
263 return (-1);
264 error = reloc_instr_imm((Elf32_Addr *)where,
265 addr + addend - (Elf_Addr)where, 27, 2);
266 break;
267 case R_AARCH64_ABS64:
268 case R_AARCH64_GLOB_DAT:
269 case R_AARCH64_JUMP_SLOT:
270 error = lookup(lf, symidx, 1, &addr);
271 if (error != 0)
272 return (-1);
273 *where = addr + addend;
274 break;
275 case R_AARCH64_IRELATIVE:
276 addr = relocbase + addend;
277 val = ((Elf64_Addr (*)(void))addr)();
278 if (*where != val)
279 *where = val;
280 break;
281 default:
282 printf("kldload: unexpected relocation type %d, "
283 "symbol index %d\n", rtype, symidx);
284 return (-1);
285 }
286 return (error);
287 }
288
289 int
elf_reloc_local(linker_file_t lf,Elf_Addr relocbase,const void * data,int type,elf_lookup_fn lookup)290 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data,
291 int type, elf_lookup_fn lookup)
292 {
293
294 return (elf_reloc_internal(lf, relocbase, data, type,
295 ARM64_ELF_RELOC_LOCAL, lookup));
296 }
297
298 /* Process one elf relocation with addend. */
299 int
elf_reloc(linker_file_t lf,Elf_Addr relocbase,const void * data,int type,elf_lookup_fn lookup)300 elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type,
301 elf_lookup_fn lookup)
302 {
303
304 return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup));
305 }
306
307 int
elf_reloc_late(linker_file_t lf,Elf_Addr relocbase,const void * data,int type,elf_lookup_fn lookup)308 elf_reloc_late(linker_file_t lf, Elf_Addr relocbase, const void *data,
309 int type, elf_lookup_fn lookup)
310 {
311
312 return (elf_reloc_internal(lf, relocbase, data, type,
313 ARM64_ELF_RELOC_LATE_IFUNC, lookup));
314 }
315
316 int
elf_cpu_load_file(linker_file_t lf)317 elf_cpu_load_file(linker_file_t lf)
318 {
319
320 if (lf->id != 1)
321 cpu_icache_sync_range(lf->address, lf->size);
322 return (0);
323 }
324
325 int
elf_cpu_unload_file(linker_file_t lf __unused)326 elf_cpu_unload_file(linker_file_t lf __unused)
327 {
328
329 return (0);
330 }
331
332 int
elf_cpu_parse_dynamic(caddr_t loadbase __unused,Elf_Dyn * dynamic __unused)333 elf_cpu_parse_dynamic(caddr_t loadbase __unused, Elf_Dyn *dynamic __unused)
334 {
335
336 return (0);
337 }
338
339 static Elf_Note gnu_property_note = {
340 .n_namesz = sizeof(GNU_ABI_VENDOR),
341 .n_descsz = 16,
342 .n_type = NT_GNU_PROPERTY_TYPE_0,
343 };
344
345 static bool
gnu_property_cb(const Elf_Note * note,void * arg0,bool * res)346 gnu_property_cb(const Elf_Note *note, void *arg0, bool *res)
347 {
348 const uint32_t *data;
349 uintptr_t p;
350
351 *res = false;
352 p = (uintptr_t)(note + 1);
353 p += roundup2(note->n_namesz, 4);
354 data = (const uint32_t *)p;
355 if (data[0] != GNU_PROPERTY_AARCH64_FEATURE_1_AND)
356 return (false);
357 /*
358 * The data length should be at least the size of a uint32, and be
359 * a multiple of uint32_t's
360 */
361 if (data[1] < sizeof(uint32_t) || (data[1] % sizeof(uint32_t)) != 0)
362 return (false);
363 if ((data[2] & GNU_PROPERTY_AARCH64_FEATURE_1_BTI) != 0)
364 *res = true;
365
366 return (true);
367 }
368
369 static void
arm64_exec_protect(struct image_params * imgp,int flags __unused)370 arm64_exec_protect(struct image_params *imgp, int flags __unused)
371 {
372 const Elf_Ehdr *hdr;
373 const Elf_Phdr *phdr;
374 vm_offset_t sva, eva;
375 int i;
376 bool found;
377
378 /* Skip if BTI is not supported */
379 if ((elf_hwcap2 & HWCAP2_BTI) == 0)
380 return;
381
382 hdr = (const Elf_Ehdr *)imgp->image_header;
383 phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
384
385 found = false;
386 for (i = 0; i < hdr->e_phnum; i++) {
387 if (phdr[i].p_type == PT_NOTE && __elfN(parse_notes)(imgp,
388 &gnu_property_note, GNU_ABI_VENDOR, &phdr[i],
389 gnu_property_cb, NULL)) {
390 found = true;
391 break;
392 }
393 }
394 if (!found)
395 return;
396
397 for (i = 0; i < hdr->e_phnum; i++) {
398 if (phdr[i].p_type != PT_LOAD || phdr[i].p_memsz == 0)
399 continue;
400
401 sva = phdr[i].p_vaddr + imgp->et_dyn_addr;
402 eva = sva + phdr[i].p_memsz;
403 pmap_bti_set(vmspace_pmap(imgp->proc->p_vmspace), sva, eva);
404 }
405 }
406