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
32 #define __ELF_WORD_SIZE 32
33
34 #include <sys/exec.h>
35 #include <sys/imgact.h>
36 #include <sys/malloc.h>
37 #include <sys/proc.h>
38 #include <sys/namei.h>
39 #include <sys/fcntl.h>
40 #include <sys/sysent.h>
41 #include <sys/imgact_elf.h>
42 #include <sys/jail.h>
43 #include <sys/reg.h>
44 #include <sys/smp.h>
45 #include <sys/syscall.h>
46 #include <sys/sysctl.h>
47 #include <sys/signalvar.h>
48 #include <sys/vnode.h>
49 #include <sys/linker.h>
50
51 #include <vm/vm.h>
52 #include <vm/vm_param.h>
53 #include <vm/pmap.h>
54 #include <vm/vm_map.h>
55
56 #include <machine/altivec.h>
57 #include <machine/cpu.h>
58 #include <machine/fpu.h>
59 #include <machine/elf.h>
60 #include <machine/md_var.h>
61
62 #include <powerpc/powerpc/elf_common.c>
63
64 #ifdef __powerpc64__
65 #include <compat/freebsd32/freebsd32_proto.h>
66 #include <compat/freebsd32/freebsd32_util.h>
67
68 extern const char *freebsd32_syscallnames[];
69 static void ppc32_fixlimit(struct rlimit *rl, int which);
70
71 static SYSCTL_NODE(_compat, OID_AUTO, ppc32, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
72 "32-bit mode");
73
74 #define PPC32_MAXDSIZ (1024*1024*1024)
75 static u_long ppc32_maxdsiz = PPC32_MAXDSIZ;
76 SYSCTL_ULONG(_compat_ppc32, OID_AUTO, maxdsiz, CTLFLAG_RWTUN, &ppc32_maxdsiz,
77 0, "");
78 #define PPC32_MAXSSIZ (64*1024*1024)
79 u_long ppc32_maxssiz = PPC32_MAXSSIZ;
80 SYSCTL_ULONG(_compat_ppc32, OID_AUTO, maxssiz, CTLFLAG_RWTUN, &ppc32_maxssiz,
81 0, "");
82 #else
83 static void ppc32_runtime_resolve(void);
84 #endif
85
86 struct sysentvec elf32_freebsd_sysvec = {
87 .sv_size = SYS_MAXSYSCALL,
88 #ifdef __powerpc64__
89 .sv_table = freebsd32_sysent,
90 #else
91 .sv_table = sysent,
92 #endif
93 .sv_fixup = __elfN(freebsd_fixup),
94 .sv_copyout_auxargs = __elfN(powerpc_copyout_auxargs),
95 .sv_sendsig = sendsig,
96 .sv_sigcode = sigcode32,
97 .sv_szsigcode = &szsigcode32,
98 .sv_name = "FreeBSD ELF32",
99 .sv_coredump = __elfN(coredump),
100 .sv_elf_core_osabi = ELFOSABI_FREEBSD,
101 .sv_elf_core_abi_vendor = FREEBSD_ABI_VENDOR,
102 .sv_elf_core_prepare_notes = __elfN(prepare_notes),
103 .sv_minsigstksz = MINSIGSTKSZ,
104 .sv_minuser = VM_MIN_ADDRESS,
105 .sv_stackprot = VM_PROT_ALL,
106 #ifdef __powerpc64__
107 .sv_maxuser = VM_MAXUSER_ADDRESS32,
108 .sv_usrstack = FREEBSD32_USRSTACK,
109 .sv_psstrings = FREEBSD32_PS_STRINGS,
110 .sv_psstringssz = sizeof(struct freebsd32_ps_strings),
111 .sv_copyout_strings = freebsd32_copyout_strings,
112 .sv_setregs = ppc32_setregs,
113 .sv_syscallnames = freebsd32_syscallnames,
114 .sv_fixlimit = ppc32_fixlimit,
115 #else
116 .sv_maxuser = VM_MAXUSER_ADDRESS,
117 .sv_usrstack = USRSTACK,
118 .sv_psstrings = PS_STRINGS,
119 .sv_psstringssz = sizeof(struct ps_strings),
120 .sv_copyout_strings = exec_copyout_strings,
121 .sv_setregs = exec_setregs,
122 .sv_syscallnames = syscallnames,
123 .sv_fixlimit = NULL,
124 #endif
125 .sv_maxssiz = NULL,
126 .sv_flags = SV_ABI_FREEBSD | SV_ILP32 | SV_SHP | SV_ASLR |
127 SV_TIMEKEEP | SV_RNG_SEED_VER | SV_SIGSYS,
128 .sv_set_syscall_retval = cpu_set_syscall_retval,
129 .sv_fetch_syscall_args = cpu_fetch_syscall_args,
130 .sv_shared_page_base = FREEBSD32_SHAREDPAGE,
131 .sv_shared_page_len = PAGE_SIZE,
132 .sv_schedtail = NULL,
133 .sv_thread_detach = NULL,
134 .sv_trap = NULL,
135 .sv_hwcap = &cpu_features,
136 .sv_hwcap2 = &cpu_features2,
137 .sv_onexec_old = exec_onexec_old,
138 .sv_onexit = exit_onexit,
139 .sv_regset_begin = SET_BEGIN(__elfN(regset)),
140 .sv_regset_end = SET_LIMIT(__elfN(regset)),
141 };
142 INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec);
143
144 static Elf32_Brandinfo freebsd_brand_info = {
145 .brand = ELFOSABI_FREEBSD,
146 .machine = EM_PPC,
147 .compat_3_brand = "FreeBSD",
148 .interp_path = "/libexec/ld-elf.so.1",
149 .sysvec = &elf32_freebsd_sysvec,
150 #ifdef __powerpc64__
151 .interp_newpath = "/libexec/ld-elf32.so.1",
152 #else
153 .interp_newpath = NULL,
154 #endif
155 .brand_note = &elf32_freebsd_brandnote,
156 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
157 };
158
159 SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST,
160 (sysinit_cfunc_t) elf32_insert_brand_entry,
161 &freebsd_brand_info);
162
163 static Elf32_Brandinfo freebsd_brand_oinfo = {
164 .brand = ELFOSABI_FREEBSD,
165 .machine = EM_PPC,
166 .compat_3_brand = "FreeBSD",
167 .interp_path = "/usr/libexec/ld-elf.so.1",
168 .sysvec = &elf32_freebsd_sysvec,
169 .interp_newpath = NULL,
170 .brand_note = &elf32_freebsd_brandnote,
171 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
172 };
173
174 SYSINIT(oelf32, SI_SUB_EXEC, SI_ORDER_ANY,
175 (sysinit_cfunc_t) elf32_insert_brand_entry,
176 &freebsd_brand_oinfo);
177
178 void elf_reloc_self(Elf_Dyn *dynp, Elf_Addr relocbase);
179
180 void
elf32_dump_thread(struct thread * td,void * dst,size_t * off)181 elf32_dump_thread(struct thread *td, void *dst, size_t *off)
182 {
183 size_t len;
184 struct pcb *pcb;
185 uint64_t vshr[32];
186 uint64_t *vsr_dw1;
187 int vsr_idx;
188
189 len = 0;
190 pcb = td->td_pcb;
191
192 if (pcb->pcb_flags & PCB_VEC) {
193 save_vec_nodrop(td);
194 if (dst != NULL) {
195 len += elf32_populate_note(NT_PPC_VMX,
196 &pcb->pcb_vec, (char *)dst + len,
197 sizeof(pcb->pcb_vec), NULL);
198 } else
199 len += elf32_populate_note(NT_PPC_VMX, NULL, NULL,
200 sizeof(pcb->pcb_vec), NULL);
201 }
202
203 if (pcb->pcb_flags & PCB_VSX) {
204 save_fpu_nodrop(td);
205 if (dst != NULL) {
206 /*
207 * Doubleword 0 of VSR0-VSR31 overlap with FPR0-FPR31 and
208 * VSR32-VSR63 overlap with VR0-VR31, so we only copy
209 * the non-overlapping data, which is doubleword 1 of VSR0-VSR31.
210 */
211 for (vsr_idx = 0; vsr_idx < nitems(vshr); vsr_idx++) {
212 vsr_dw1 = (uint64_t *)&pcb->pcb_fpu.fpr[vsr_idx].vsr[2];
213 vshr[vsr_idx] = *vsr_dw1;
214 }
215 len += elf32_populate_note(NT_PPC_VSX,
216 vshr, (char *)dst + len,
217 sizeof(vshr), NULL);
218 } else
219 len += elf32_populate_note(NT_PPC_VSX, NULL, NULL,
220 sizeof(vshr), NULL);
221 }
222
223 *off = len;
224 }
225
226 #ifndef __powerpc64__
227 bool
elf_is_ifunc_reloc(Elf_Size r_info)228 elf_is_ifunc_reloc(Elf_Size r_info)
229 {
230
231 return (ELF_R_TYPE(r_info) == R_PPC_IRELATIVE);
232 }
233
234 /* Process one elf relocation with addend. */
235 static int
elf_reloc_internal(linker_file_t lf,Elf_Addr relocbase,const void * data,int type,int local,elf_lookup_fn lookup)236 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data,
237 int type, int local, elf_lookup_fn lookup)
238 {
239 Elf_Addr *where;
240 Elf_Half *hwhere;
241 Elf_Addr addr;
242 Elf_Addr addend, val;
243 Elf_Word rtype, symidx;
244 const Elf_Rela *rela;
245 int error;
246
247 switch (type) {
248 case ELF_RELOC_REL:
249 panic("PPC only supports RELA relocations");
250 break;
251 case ELF_RELOC_RELA:
252 rela = (const Elf_Rela *)data;
253 where = (Elf_Addr *) ((uintptr_t)relocbase + rela->r_offset);
254 hwhere = (Elf_Half *) ((uintptr_t)relocbase + rela->r_offset);
255 addend = rela->r_addend;
256 rtype = ELF_R_TYPE(rela->r_info);
257 symidx = ELF_R_SYM(rela->r_info);
258 break;
259 default:
260 panic("elf_reloc: unknown relocation mode %d\n", type);
261 }
262
263 switch (rtype) {
264 case R_PPC_NONE:
265 break;
266
267 case R_PPC_ADDR32: /* word32 S + A */
268 error = lookup(lf, symidx, 1, &addr);
269 if (error != 0)
270 return (-1);
271 *where = elf_relocaddr(lf, addr + addend);
272 break;
273
274 case R_PPC_ADDR16_LO: /* #lo(S) */
275 error = lookup(lf, symidx, 1, &addr);
276 if (error != 0)
277 return (-1);
278 /*
279 * addend values are sometimes relative to sections
280 * (i.e. .rodata) in rela, where in reality they
281 * are relative to relocbase. Detect this condition.
282 */
283 if (addr > relocbase && addr <= (relocbase + addend))
284 addr = relocbase;
285 addr = elf_relocaddr(lf, addr + addend);
286 *hwhere = addr & 0xffff;
287 break;
288
289 case R_PPC_ADDR16_HA: /* #ha(S) */
290 error = lookup(lf, symidx, 1, &addr);
291 if (error != 0)
292 return (-1);
293 /*
294 * addend values are sometimes relative to sections
295 * (i.e. .rodata) in rela, where in reality they
296 * are relative to relocbase. Detect this condition.
297 */
298 if (addr > relocbase && addr <= (relocbase + addend))
299 addr = relocbase;
300 addr = elf_relocaddr(lf, addr + addend);
301 *hwhere = ((addr >> 16) + ((addr & 0x8000) ? 1 : 0))
302 & 0xffff;
303 break;
304
305 case R_PPC_RELATIVE: /* word32 B + A */
306 *where = elf_relocaddr(lf, relocbase + addend);
307 break;
308
309 case R_PPC_JMP_SLOT: /* PLT jump slot entry */
310 /*
311 * We currently only support Secure-PLT jump slots.
312 * Given that we reject BSS-PLT modules during load, we
313 * don't need to check again.
314 * The method we are using here is equivilent to
315 * LD_BIND_NOW.
316 */
317 error = lookup(lf, symidx, 1, &addr);
318 if (error != 0)
319 return (-1);
320 *where = elf_relocaddr(lf, addr + addend);
321 break;
322
323 case R_PPC_IRELATIVE:
324 addr = relocbase + addend;
325 val = ((Elf32_Addr (*)(void))addr)();
326 if (*where != val)
327 *where = val;
328 break;
329
330 default:
331 printf("kldload: unexpected relocation type %d, "
332 "symbol index %d\n", (int)rtype, symidx);
333 return (-1);
334 }
335 return (0);
336 }
337
338 void
elf_reloc_self(Elf_Dyn * dynp,Elf_Addr relocbase)339 elf_reloc_self(Elf_Dyn *dynp, Elf_Addr relocbase)
340 {
341 Elf_Rela *rela = NULL, *relalim;
342 Elf_Addr relasz = 0;
343 Elf_Addr *where;
344
345 /*
346 * Extract the rela/relasz values from the dynamic section
347 */
348 for (; dynp->d_tag != DT_NULL; dynp++) {
349 switch (dynp->d_tag) {
350 case DT_RELA:
351 rela = (Elf_Rela *)(relocbase+dynp->d_un.d_ptr);
352 break;
353 case DT_RELASZ:
354 relasz = dynp->d_un.d_val;
355 break;
356 }
357 }
358
359 /*
360 * Relocate these values
361 */
362 relalim = (Elf_Rela *)((caddr_t)rela + relasz);
363 for (; rela < relalim; rela++) {
364 if (ELF_R_TYPE(rela->r_info) != R_PPC_RELATIVE)
365 continue;
366 where = (Elf_Addr *)(relocbase + rela->r_offset);
367 *where = (Elf_Addr)(relocbase + rela->r_addend);
368 }
369 }
370
371 int
elf_reloc(linker_file_t lf,Elf_Addr relocbase,const void * data,int type,elf_lookup_fn lookup)372 elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type,
373 elf_lookup_fn lookup)
374 {
375
376 return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup));
377 }
378
379 int
elf_reloc_local(linker_file_t lf,Elf_Addr relocbase,const void * data,int type,elf_lookup_fn lookup)380 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data,
381 int type, elf_lookup_fn lookup)
382 {
383
384 return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup));
385 }
386
387 int
elf_cpu_load_file(linker_file_t lf)388 elf_cpu_load_file(linker_file_t lf)
389 {
390
391 /* Only sync the cache for non-kernel modules */
392 if (lf->id != 1)
393 __syncicache(lf->address, lf->size);
394 return (0);
395 }
396
397 int
elf_cpu_unload_file(linker_file_t lf __unused)398 elf_cpu_unload_file(linker_file_t lf __unused)
399 {
400
401 return (0);
402 }
403
404 static void
ppc32_runtime_resolve(void)405 ppc32_runtime_resolve(void)
406 {
407
408 /*
409 * Since we don't support lazy binding, panic immediately if anyone
410 * manages to call the runtime resolver.
411 */
412 panic("kldload: Runtime resolver was called unexpectedly!");
413 }
414
415 int
elf_cpu_parse_dynamic(caddr_t loadbase,Elf_Dyn * dynamic)416 elf_cpu_parse_dynamic(caddr_t loadbase, Elf_Dyn *dynamic)
417 {
418 Elf_Dyn *dp;
419 bool has_plt = false;
420 bool secure_plt = false;
421 Elf_Addr *got;
422
423 for (dp = dynamic; dp->d_tag != DT_NULL; dp++) {
424 switch (dp->d_tag) {
425 case DT_PPC_GOT:
426 secure_plt = true;
427 got = (Elf_Addr *)(loadbase + dp->d_un.d_ptr);
428 /* Install runtime resolver canary. */
429 got[1] = (Elf_Addr)ppc32_runtime_resolve;
430 got[2] = (Elf_Addr)0;
431 break;
432 case DT_PLTGOT:
433 has_plt = true;
434 break;
435 }
436 }
437
438 if (has_plt && !secure_plt) {
439 printf("kldload: BSS-PLT modules are not supported.\n");
440 return (-1);
441 }
442 return (0);
443 }
444 #endif
445
446 #ifdef __powerpc64__
447 static void
ppc32_fixlimit(struct rlimit * rl,int which)448 ppc32_fixlimit(struct rlimit *rl, int which)
449 {
450 switch (which) {
451 case RLIMIT_DATA:
452 if (ppc32_maxdsiz != 0) {
453 if (rl->rlim_cur > ppc32_maxdsiz)
454 rl->rlim_cur = ppc32_maxdsiz;
455 if (rl->rlim_max > ppc32_maxdsiz)
456 rl->rlim_max = ppc32_maxdsiz;
457 }
458 break;
459 case RLIMIT_STACK:
460 if (ppc32_maxssiz != 0) {
461 if (rl->rlim_cur > ppc32_maxssiz)
462 rl->rlim_cur = ppc32_maxssiz;
463 if (rl->rlim_max > ppc32_maxssiz)
464 rl->rlim_max = ppc32_maxssiz;
465 }
466 break;
467 }
468 }
469 #endif
470