xref: /freebsd/sys/powerpc/powerpc/elf64_machdep.c (revision 9768746b)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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  * $FreeBSD$
28  */
29 
30 #include <sys/param.h>
31 #include <sys/kernel.h>
32 #include <sys/systm.h>
33 #include <sys/elf.h>
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/reg.h>
41 #include <sys/sysent.h>
42 #include <sys/imgact_elf.h>
43 #include <sys/jail.h>
44 #include <sys/smp.h>
45 #include <sys/syscall.h>
46 #include <sys/signalvar.h>
47 #include <sys/vnode.h>
48 #include <sys/linker.h>
49 
50 #include <vm/vm.h>
51 #include <vm/vm_param.h>
52 #include <vm/pmap.h>
53 #include <vm/vm_map.h>
54 
55 #include <machine/altivec.h>
56 #include <machine/cpu.h>
57 #include <machine/fpu.h>
58 #include <machine/elf.h>
59 #include <machine/md_var.h>
60 
61 #include <powerpc/powerpc/elf_common.c>
62 
63 static void exec_setregs_funcdesc(struct thread *td, struct image_params *imgp,
64     uintptr_t stack);
65 
66 struct sysentvec elf64_freebsd_sysvec_v1 = {
67 	.sv_size	= SYS_MAXSYSCALL,
68 	.sv_table	= sysent,
69 	.sv_fixup	= __elfN(freebsd_fixup),
70 	.sv_sendsig	= sendsig,
71 	.sv_sigcode	= sigcode64,
72 	.sv_szsigcode	= &szsigcode64,
73 	.sv_name	= "FreeBSD ELF64",
74 	.sv_coredump	= __elfN(coredump),
75 	.sv_elf_core_osabi = ELFOSABI_FREEBSD,
76 	.sv_elf_core_abi_vendor = FREEBSD_ABI_VENDOR,
77 	.sv_elf_core_prepare_notes = __elfN(prepare_notes),
78 	.sv_imgact_try	= NULL,
79 	.sv_minsigstksz	= MINSIGSTKSZ,
80 	.sv_minuser	= VM_MIN_ADDRESS,
81 	.sv_maxuser	= VM_MAXUSER_ADDRESS,
82 	.sv_usrstack	= USRSTACK,
83 	.sv_psstrings	= PS_STRINGS,
84 	.sv_psstringssz	= sizeof(struct ps_strings),
85 	.sv_stackprot	= VM_PROT_ALL,
86 	.sv_copyout_auxargs = __elfN(powerpc_copyout_auxargs),
87 	.sv_copyout_strings = exec_copyout_strings,
88 	.sv_setregs	= exec_setregs_funcdesc,
89 	.sv_fixlimit	= NULL,
90 	.sv_maxssiz	= NULL,
91 	.sv_flags	= SV_ABI_FREEBSD | SV_LP64 | SV_SHP | SV_ASLR |
92 			    SV_TIMEKEEP | SV_RNG_SEED_VER,
93 	.sv_set_syscall_retval = cpu_set_syscall_retval,
94 	.sv_fetch_syscall_args = cpu_fetch_syscall_args,
95 	.sv_syscallnames = syscallnames,
96 	.sv_shared_page_base = SHAREDPAGE,
97 	.sv_shared_page_len = PAGE_SIZE,
98 	.sv_schedtail	= NULL,
99 	.sv_thread_detach = NULL,
100 	.sv_trap	= NULL,
101 	.sv_hwcap	= &cpu_features,
102 	.sv_hwcap2	= &cpu_features2,
103 	.sv_onexec_old	= exec_onexec_old,
104 	.sv_onexit	= exit_onexit,
105 	.sv_regset_begin = SET_BEGIN(__elfN(regset)),
106 	.sv_regset_end  = SET_LIMIT(__elfN(regset)),
107 };
108 
109 struct sysentvec elf64_freebsd_sysvec_v2 = {
110 	.sv_size	= SYS_MAXSYSCALL,
111 	.sv_table	= sysent,
112 	.sv_fixup	= __elfN(freebsd_fixup),
113 	.sv_sendsig	= sendsig,
114 	.sv_sigcode	= sigcode64, /* Fixed up in ppc64_init_sysvecs(). */
115 	.sv_szsigcode	= &szsigcode64,
116 	.sv_name	= "FreeBSD ELF64 V2",
117 	.sv_coredump	= __elfN(coredump),
118 	.sv_elf_core_osabi = ELFOSABI_FREEBSD,
119 	.sv_elf_core_abi_vendor = FREEBSD_ABI_VENDOR,
120 	.sv_elf_core_prepare_notes = __elfN(prepare_notes),
121 	.sv_imgact_try	= NULL,
122 	.sv_minsigstksz	= MINSIGSTKSZ,
123 	.sv_minuser	= VM_MIN_ADDRESS,
124 	.sv_maxuser	= VM_MAXUSER_ADDRESS,
125 	.sv_usrstack	= USRSTACK,
126 	.sv_psstrings	= PS_STRINGS,
127 	.sv_psstringssz	= sizeof(struct ps_strings),
128 	.sv_stackprot	= VM_PROT_ALL,
129 	.sv_copyout_auxargs = __elfN(powerpc_copyout_auxargs),
130 	.sv_copyout_strings = exec_copyout_strings,
131 	.sv_setregs	= exec_setregs,
132 	.sv_fixlimit	= NULL,
133 	.sv_maxssiz	= NULL,
134 	.sv_flags	= SV_ABI_FREEBSD | SV_LP64 | SV_SHP |
135 			    SV_TIMEKEEP | SV_RNG_SEED_VER,
136 	.sv_set_syscall_retval = cpu_set_syscall_retval,
137 	.sv_fetch_syscall_args = cpu_fetch_syscall_args,
138 	.sv_syscallnames = syscallnames,
139 	.sv_shared_page_base = SHAREDPAGE,
140 	.sv_shared_page_len = PAGE_SIZE,
141 	.sv_schedtail	= NULL,
142 	.sv_thread_detach = NULL,
143 	.sv_trap	= NULL,
144 	.sv_hwcap	= &cpu_features,
145 	.sv_hwcap2	= &cpu_features2,
146 	.sv_onexec_old	= exec_onexec_old,
147 	.sv_onexit	= exit_onexit,
148 	.sv_regset_begin = SET_BEGIN(__elfN(regset)),
149 	.sv_regset_end  = SET_LIMIT(__elfN(regset)),
150 };
151 
152 static boolean_t ppc64_elfv1_header_match(struct image_params *params,
153     int32_t *, uint32_t *);
154 static boolean_t ppc64_elfv2_header_match(struct image_params *params,
155     int32_t *, uint32_t *);
156 
157 static Elf64_Brandinfo freebsd_brand_info_elfv1 = {
158 	.brand		= ELFOSABI_FREEBSD,
159 	.machine	= EM_PPC64,
160 	.compat_3_brand	= "FreeBSD",
161 	.emul_path	= NULL,
162 	.interp_path	= "/libexec/ld-elf.so.1",
163 	.sysvec		= &elf64_freebsd_sysvec_v1,
164 	.interp_newpath	= NULL,
165 	.brand_note	= &elf64_freebsd_brandnote,
166 	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE,
167 	.header_supported = &ppc64_elfv1_header_match
168 };
169 
170 SYSINIT(elf64v1, SI_SUB_EXEC, SI_ORDER_ANY,
171     (sysinit_cfunc_t) elf64_insert_brand_entry,
172     &freebsd_brand_info_elfv1);
173 
174 static Elf64_Brandinfo freebsd_brand_info_elfv2 = {
175 	.brand		= ELFOSABI_FREEBSD,
176 	.machine	= EM_PPC64,
177 	.compat_3_brand	= "FreeBSD",
178 	.emul_path	= NULL,
179 	.interp_path	= "/libexec/ld-elf.so.1",
180 	.sysvec		= &elf64_freebsd_sysvec_v2,
181 	.interp_newpath	= NULL,
182 	.brand_note	= &elf64_freebsd_brandnote,
183 	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE,
184 	.header_supported = &ppc64_elfv2_header_match
185 };
186 
187 SYSINIT(elf64v2, SI_SUB_EXEC, SI_ORDER_ANY,
188     (sysinit_cfunc_t) elf64_insert_brand_entry,
189     &freebsd_brand_info_elfv2);
190 
191 static Elf64_Brandinfo freebsd_brand_oinfo = {
192 	.brand		= ELFOSABI_FREEBSD,
193 	.machine	= EM_PPC64,
194 	.compat_3_brand	= "FreeBSD",
195 	.emul_path	= NULL,
196 	.interp_path	= "/usr/libexec/ld-elf.so.1",
197 	.sysvec		= &elf64_freebsd_sysvec_v1,
198 	.interp_newpath	= NULL,
199 	.brand_note	= &elf64_freebsd_brandnote,
200 	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE,
201 	.header_supported = &ppc64_elfv1_header_match
202 };
203 
204 SYSINIT(oelf64, SI_SUB_EXEC, SI_ORDER_ANY,
205 	(sysinit_cfunc_t) elf64_insert_brand_entry,
206 	&freebsd_brand_oinfo);
207 
208 void elf_reloc_self(Elf_Dyn *dynp, Elf_Addr relocbase);
209 
210 static void
211 ppc64_init_sysvecs(void *arg)
212 {
213 	exec_sysvec_init(&elf64_freebsd_sysvec_v2);
214 	exec_sysvec_init_secondary(&elf64_freebsd_sysvec_v2,
215 	    &elf64_freebsd_sysvec_v1);
216 	/*
217 	 * Adjust elfv2 sigcode after elfv1 sysvec is initialized.
218 	 * exec_sysvec_init_secondary() assumes secondary sysvecs use
219 	 * identical signal code, and skips allocating a second copy.
220 	 * Since the ELFv2 trampoline is a strict subset of the ELFv1 code,
221 	 * we can work around this by adjusting the offset. This also
222 	 * avoids two copies of the trampoline code being allocated!
223 	 */
224 	elf64_freebsd_sysvec_v2.sv_sigcode_offset +=
225 	    (uintptr_t)sigcode64_elfv2 - (uintptr_t)&sigcode64;
226 	elf64_freebsd_sysvec_v2.sv_szsigcode = &szsigcode64_elfv2;
227 }
228 SYSINIT(elf64_sysvec, SI_SUB_EXEC, SI_ORDER_ANY, ppc64_init_sysvecs, NULL);
229 
230 static boolean_t
231 ppc64_elfv1_header_match(struct image_params *params, int32_t *osrel __unused,
232     uint32_t *fctl0 __unused)
233 {
234 	const Elf64_Ehdr *hdr = (const Elf64_Ehdr *)params->image_header;
235 	int abi = (hdr->e_flags & 3);
236 
237 	return (abi == 0 || abi == 1);
238 }
239 
240 static boolean_t
241 ppc64_elfv2_header_match(struct image_params *params, int32_t *osrel __unused,
242     uint32_t *fctl0 __unused)
243 {
244 	const Elf64_Ehdr *hdr = (const Elf64_Ehdr *)params->image_header;
245 	int abi = (hdr->e_flags & 3);
246 
247 	return (abi == 2);
248 }
249 
250 static void
251 exec_setregs_funcdesc(struct thread *td, struct image_params *imgp,
252     uintptr_t stack)
253 {
254 	struct trapframe *tf;
255 	register_t entry_desc[3];
256 
257 	tf = trapframe(td);
258 	exec_setregs(td, imgp, stack);
259 
260 	/*
261 	 * For 64-bit ELFv1, we need to disentangle the function
262 	 * descriptor
263 	 *
264 	 * 0. entry point
265 	 * 1. TOC value (r2)
266 	 * 2. Environment pointer (r11)
267 	 */
268 
269 	(void)copyin((void *)imgp->entry_addr, entry_desc,
270 	    sizeof(entry_desc));
271 	tf->srr0 = entry_desc[0] + imgp->reloc_base;
272 	tf->fixreg[2] = entry_desc[1] + imgp->reloc_base;
273 	tf->fixreg[11] = entry_desc[2] + imgp->reloc_base;
274 }
275 
276 void
277 elf64_dump_thread(struct thread *td, void *dst, size_t *off)
278 {
279 	size_t len;
280 	struct pcb *pcb;
281 	uint64_t vshr[32];
282 	uint64_t *vsr_dw1;
283 	int vsr_idx;
284 
285 	len = 0;
286 	pcb = td->td_pcb;
287 
288 	if (pcb->pcb_flags & PCB_VEC) {
289 		save_vec_nodrop(td);
290 		if (dst != NULL) {
291 			len += elf64_populate_note(NT_PPC_VMX,
292 			    &pcb->pcb_vec, (char *)dst + len,
293 			    sizeof(pcb->pcb_vec), NULL);
294 		} else
295 			len += elf64_populate_note(NT_PPC_VMX, NULL, NULL,
296 			    sizeof(pcb->pcb_vec), NULL);
297 	}
298 
299 	if (pcb->pcb_flags & PCB_VSX) {
300 		save_fpu_nodrop(td);
301 		if (dst != NULL) {
302 			/*
303 			 * Doubleword 0 of VSR0-VSR31 overlap with FPR0-FPR31 and
304 			 * VSR32-VSR63 overlap with VR0-VR31, so we only copy
305 			 * the non-overlapping data, which is doubleword 1 of VSR0-VSR31.
306 			 */
307 			for (vsr_idx = 0; vsr_idx < nitems(vshr); vsr_idx++) {
308 				vsr_dw1 = (uint64_t *)&pcb->pcb_fpu.fpr[vsr_idx].vsr[2];
309 				vshr[vsr_idx] = *vsr_dw1;
310 			}
311 			len += elf64_populate_note(NT_PPC_VSX,
312 			    vshr, (char *)dst + len,
313 			    sizeof(vshr), NULL);
314 		} else
315 			len += elf64_populate_note(NT_PPC_VSX, NULL, NULL,
316 			    sizeof(vshr), NULL);
317 	}
318 
319 	*off = len;
320 }
321 
322 bool
323 elf_is_ifunc_reloc(Elf_Size r_info)
324 {
325 
326 	return (ELF_R_TYPE(r_info) == R_PPC_IRELATIVE);
327 }
328 
329 /* Process one elf relocation with addend. */
330 static int
331 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data,
332     int type, int local, elf_lookup_fn lookup)
333 {
334 	Elf_Addr *where;
335 	Elf_Addr addr;
336 	Elf_Addr addend, val;
337 	Elf_Word rtype, symidx;
338 	const Elf_Rela *rela;
339 	int error;
340 
341 	switch (type) {
342 	case ELF_RELOC_REL:
343 		panic("PPC only supports RELA relocations");
344 		break;
345 	case ELF_RELOC_RELA:
346 		rela = (const Elf_Rela *)data;
347 		where = (Elf_Addr *) (relocbase + rela->r_offset);
348 		addend = rela->r_addend;
349 		rtype = ELF_R_TYPE(rela->r_info);
350 		symidx = ELF_R_SYM(rela->r_info);
351 		break;
352 	default:
353 		panic("elf_reloc: unknown relocation mode %d\n", type);
354 	}
355 
356 	switch (rtype) {
357 	case R_PPC_NONE:
358 		break;
359 
360 	case R_PPC64_ADDR64:	/* doubleword64 S + A */
361 		error = lookup(lf, symidx, 1, &addr);
362 		if (error != 0)
363 			return (-1);
364 		addr += addend;
365 		*where = addr;
366 		break;
367 
368 	case R_PPC_RELATIVE:	/* doubleword64 B + A */
369 		*where = elf_relocaddr(lf, relocbase + addend);
370 		break;
371 
372 	case R_PPC_JMP_SLOT:	/* function descriptor copy */
373 		lookup(lf, symidx, 1, &addr);
374 #if !defined(_CALL_ELF) || _CALL_ELF == 1
375 		memcpy(where, (Elf_Addr *)addr, 3*sizeof(Elf_Addr));
376 #else
377 		*where = addr;
378 #endif
379 		__asm __volatile("dcbst 0,%0; sync" :: "r"(where) : "memory");
380 		break;
381 
382 	case R_PPC_IRELATIVE:
383 		addr = relocbase + addend;
384 		val = ((Elf64_Addr (*)(void))addr)();
385 		if (*where != val)
386 			*where = val;
387 		break;
388 
389 	default:
390 		printf("kldload: unexpected relocation type %d, "
391 		    "symbol index %d\n", (int)rtype, symidx);
392 		return (-1);
393 	}
394 	return (0);
395 }
396 
397 void
398 elf_reloc_self(Elf_Dyn *dynp, Elf_Addr relocbase)
399 {
400 	Elf_Rela *rela = NULL, *relalim;
401 	Elf_Addr relasz = 0;
402 	Elf_Addr *where;
403 
404 	/*
405 	 * Extract the rela/relasz values from the dynamic section
406 	 */
407 	for (; dynp->d_tag != DT_NULL; dynp++) {
408 		switch (dynp->d_tag) {
409 		case DT_RELA:
410 			rela = (Elf_Rela *)(relocbase+dynp->d_un.d_ptr);
411 			break;
412 		case DT_RELASZ:
413 			relasz = dynp->d_un.d_val;
414 			break;
415 		}
416 	}
417 
418 	/*
419 	 * Relocate these values
420 	 */
421 	relalim = (Elf_Rela *)((caddr_t)rela + relasz);
422 	for (; rela < relalim; rela++) {
423 		if (ELF_R_TYPE(rela->r_info) != R_PPC_RELATIVE)
424 			continue;
425 		where = (Elf_Addr *)(relocbase + rela->r_offset);
426 		*where = (Elf_Addr)(relocbase + rela->r_addend);
427 	}
428 }
429 
430 int
431 elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type,
432     elf_lookup_fn lookup)
433 {
434 
435 	return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup));
436 }
437 
438 int
439 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data,
440     int type, elf_lookup_fn lookup)
441 {
442 
443 	return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup));
444 }
445 
446 int
447 elf_cpu_load_file(linker_file_t lf)
448 {
449 	/* Only sync the cache for non-kernel modules */
450 	if (lf->id != 1)
451 		__syncicache(lf->address, lf->size);
452 	return (0);
453 }
454 
455 int
456 elf_cpu_unload_file(linker_file_t lf __unused)
457 {
458 
459 	return (0);
460 }
461 
462 int
463 elf_cpu_parse_dynamic(caddr_t loadbase __unused, Elf_Dyn *dynamic __unused)
464 {
465 
466 	return (0);
467 }
468