xref: /freebsd/sys/powerpc/powerpc/elf64_machdep.c (revision f66a407de25eaa4c58b4f6f02086d55141593b63)
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/elf.h>
32 #include <sys/exec.h>
33 #include <sys/imgact.h>
34 #include <sys/malloc.h>
35 #include <sys/proc.h>
36 #include <sys/namei.h>
37 #include <sys/fcntl.h>
38 #include <sys/reg.h>
39 #include <sys/sysent.h>
40 #include <sys/imgact_elf.h>
41 #include <sys/jail.h>
42 #include <sys/smp.h>
43 #include <sys/syscall.h>
44 #include <sys/signalvar.h>
45 #include <sys/vnode.h>
46 #include <sys/linker.h>
47 
48 #include <vm/vm.h>
49 #include <vm/vm_param.h>
50 #include <vm/pmap.h>
51 #include <vm/vm_map.h>
52 
53 #include <machine/altivec.h>
54 #include <machine/cpu.h>
55 #include <machine/fpu.h>
56 #include <machine/elf.h>
57 #include <machine/md_var.h>
58 
59 #include <powerpc/powerpc/elf_common.c>
60 
61 static void exec_setregs_funcdesc(struct thread *td, struct image_params *imgp,
62     uintptr_t stack);
63 
64 struct sysentvec elf64_freebsd_sysvec_v1 = {
65 	.sv_size	= SYS_MAXSYSCALL,
66 	.sv_table	= sysent,
67 	.sv_fixup	= __elfN(freebsd_fixup),
68 	.sv_sendsig	= sendsig,
69 	.sv_sigcode	= sigcode64,
70 	.sv_szsigcode	= &szsigcode64,
71 	.sv_name	= "FreeBSD ELF64",
72 	.sv_coredump	= __elfN(coredump),
73 	.sv_elf_core_osabi = ELFOSABI_FREEBSD,
74 	.sv_elf_core_abi_vendor = FREEBSD_ABI_VENDOR,
75 	.sv_elf_core_prepare_notes = __elfN(prepare_notes),
76 	.sv_minsigstksz	= MINSIGSTKSZ,
77 	.sv_minuser	= VM_MIN_ADDRESS,
78 	.sv_maxuser	= VM_MAXUSER_ADDRESS,
79 	.sv_usrstack	= USRSTACK,
80 	.sv_psstrings	= PS_STRINGS,
81 	.sv_psstringssz	= sizeof(struct ps_strings),
82 	.sv_stackprot	= VM_PROT_ALL,
83 	.sv_copyout_auxargs = __elfN(powerpc_copyout_auxargs),
84 	.sv_copyout_strings = exec_copyout_strings,
85 	.sv_setregs	= exec_setregs_funcdesc,
86 	.sv_fixlimit	= NULL,
87 	.sv_maxssiz	= NULL,
88 	.sv_flags	= SV_ABI_FREEBSD | SV_LP64 | SV_SHP | SV_ASLR |
89 			    SV_TIMEKEEP | SV_RNG_SEED_VER | 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	= &cpu_features,
99 	.sv_hwcap2	= &cpu_features2,
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 
106 struct sysentvec elf64_freebsd_sysvec_v2 = {
107 	.sv_size	= SYS_MAXSYSCALL,
108 	.sv_table	= sysent,
109 	.sv_fixup	= __elfN(freebsd_fixup),
110 	.sv_sendsig	= sendsig,
111 	.sv_sigcode	= sigcode64, /* Fixed up in ppc64_init_sysvecs(). */
112 	.sv_szsigcode	= &szsigcode64,
113 	.sv_name	= "FreeBSD ELF64 V2",
114 	.sv_coredump	= __elfN(coredump),
115 	.sv_elf_core_osabi = ELFOSABI_FREEBSD,
116 	.sv_elf_core_abi_vendor = FREEBSD_ABI_VENDOR,
117 	.sv_elf_core_prepare_notes = __elfN(prepare_notes),
118 	.sv_minsigstksz	= MINSIGSTKSZ,
119 	.sv_minuser	= VM_MIN_ADDRESS,
120 	.sv_maxuser	= VM_MAXUSER_ADDRESS,
121 	.sv_usrstack	= USRSTACK,
122 	.sv_psstrings	= PS_STRINGS,
123 	.sv_psstringssz	= sizeof(struct ps_strings),
124 	.sv_stackprot	= VM_PROT_ALL,
125 	.sv_copyout_auxargs = __elfN(powerpc_copyout_auxargs),
126 	.sv_copyout_strings = exec_copyout_strings,
127 	.sv_setregs	= exec_setregs,
128 	.sv_fixlimit	= NULL,
129 	.sv_maxssiz	= NULL,
130 	.sv_flags	= SV_ABI_FREEBSD | SV_LP64 | SV_SHP |
131 			    SV_TIMEKEEP | SV_RNG_SEED_VER | SV_SIGSYS,
132 	.sv_set_syscall_retval = cpu_set_syscall_retval,
133 	.sv_fetch_syscall_args = cpu_fetch_syscall_args,
134 	.sv_syscallnames = syscallnames,
135 	.sv_shared_page_base = SHAREDPAGE,
136 	.sv_shared_page_len = PAGE_SIZE,
137 	.sv_schedtail	= NULL,
138 	.sv_thread_detach = NULL,
139 	.sv_trap	= NULL,
140 	.sv_hwcap	= &cpu_features,
141 	.sv_hwcap2	= &cpu_features2,
142 	.sv_onexec_old	= exec_onexec_old,
143 	.sv_onexit	= exit_onexit,
144 	.sv_regset_begin = SET_BEGIN(__elfN(regset)),
145 	.sv_regset_end  = SET_LIMIT(__elfN(regset)),
146 };
147 
148 static bool ppc64_elfv1_header_match(const struct image_params *params,
149     const int32_t *, const uint32_t *);
150 static bool ppc64_elfv2_header_match(const struct image_params *params,
151     const int32_t *, const uint32_t *);
152 
153 static Elf64_Brandinfo freebsd_brand_info_elfv1 = {
154 	.brand		= ELFOSABI_FREEBSD,
155 	.machine	= EM_PPC64,
156 	.compat_3_brand	= "FreeBSD",
157 	.interp_path	= "/libexec/ld-elf.so.1",
158 	.sysvec		= &elf64_freebsd_sysvec_v1,
159 	.interp_newpath	= NULL,
160 	.brand_note	= &elf64_freebsd_brandnote,
161 	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE,
162 	.header_supported = &ppc64_elfv1_header_match
163 };
164 
165 SYSINIT(elf64v1, SI_SUB_EXEC, SI_ORDER_ANY,
166     (sysinit_cfunc_t) elf64_insert_brand_entry,
167     &freebsd_brand_info_elfv1);
168 
169 static Elf64_Brandinfo freebsd_brand_info_elfv2 = {
170 	.brand		= ELFOSABI_FREEBSD,
171 	.machine	= EM_PPC64,
172 	.compat_3_brand	= "FreeBSD",
173 	.interp_path	= "/libexec/ld-elf.so.1",
174 	.sysvec		= &elf64_freebsd_sysvec_v2,
175 	.interp_newpath	= NULL,
176 	.brand_note	= &elf64_freebsd_brandnote,
177 	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE,
178 	.header_supported = &ppc64_elfv2_header_match
179 };
180 
181 SYSINIT(elf64v2, SI_SUB_EXEC, SI_ORDER_ANY,
182     (sysinit_cfunc_t) elf64_insert_brand_entry,
183     &freebsd_brand_info_elfv2);
184 
185 static Elf64_Brandinfo freebsd_brand_oinfo = {
186 	.brand		= ELFOSABI_FREEBSD,
187 	.machine	= EM_PPC64,
188 	.compat_3_brand	= "FreeBSD",
189 	.interp_path	= "/usr/libexec/ld-elf.so.1",
190 	.sysvec		= &elf64_freebsd_sysvec_v1,
191 	.interp_newpath	= NULL,
192 	.brand_note	= &elf64_freebsd_brandnote,
193 	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE,
194 	.header_supported = &ppc64_elfv1_header_match
195 };
196 
197 SYSINIT(oelf64, SI_SUB_EXEC, SI_ORDER_ANY,
198 	(sysinit_cfunc_t) elf64_insert_brand_entry,
199 	&freebsd_brand_oinfo);
200 
201 void elf_reloc_self(Elf_Dyn *dynp, Elf_Addr relocbase);
202 
203 static void
ppc64_init_sysvecs(void * arg)204 ppc64_init_sysvecs(void *arg)
205 {
206 	exec_sysvec_init(&elf64_freebsd_sysvec_v2);
207 	exec_sysvec_init_secondary(&elf64_freebsd_sysvec_v2,
208 	    &elf64_freebsd_sysvec_v1);
209 	/*
210 	 * Adjust elfv2 sigcode after elfv1 sysvec is initialized.
211 	 * exec_sysvec_init_secondary() assumes secondary sysvecs use
212 	 * identical signal code, and skips allocating a second copy.
213 	 * Since the ELFv2 trampoline is a strict subset of the ELFv1 code,
214 	 * we can work around this by adjusting the offset. This also
215 	 * avoids two copies of the trampoline code being allocated!
216 	 */
217 	elf64_freebsd_sysvec_v2.sv_sigcode_offset +=
218 	    (uintptr_t)sigcode64_elfv2 - (uintptr_t)&sigcode64;
219 	elf64_freebsd_sysvec_v2.sv_szsigcode = &szsigcode64_elfv2;
220 }
221 SYSINIT(elf64_sysvec, SI_SUB_EXEC, SI_ORDER_ANY, ppc64_init_sysvecs, NULL);
222 
223 static bool
ppc64_elfv1_header_match(const struct image_params * params,const int32_t * osrel __unused,const uint32_t * fctl0 __unused)224 ppc64_elfv1_header_match(const struct image_params *params,
225     const int32_t *osrel __unused, const uint32_t *fctl0 __unused)
226 {
227 	const Elf64_Ehdr *hdr = (const Elf64_Ehdr *)params->image_header;
228 	int abi = (hdr->e_flags & 3);
229 
230 	return (abi == 0 || abi == 1);
231 }
232 
233 static bool
ppc64_elfv2_header_match(const struct image_params * params,const int32_t * osrel __unused,const uint32_t * fctl0 __unused)234 ppc64_elfv2_header_match(const struct image_params *params,
235     const int32_t *osrel __unused, const uint32_t *fctl0 __unused)
236 {
237 	const Elf64_Ehdr *hdr = (const Elf64_Ehdr *)params->image_header;
238 	int abi = (hdr->e_flags & 3);
239 
240 	return (abi == 2);
241 }
242 
243 static void
exec_setregs_funcdesc(struct thread * td,struct image_params * imgp,uintptr_t stack)244 exec_setregs_funcdesc(struct thread *td, struct image_params *imgp,
245     uintptr_t stack)
246 {
247 	struct trapframe *tf;
248 	register_t entry_desc[3];
249 
250 	tf = trapframe(td);
251 	exec_setregs(td, imgp, stack);
252 
253 	/*
254 	 * For 64-bit ELFv1, we need to disentangle the function
255 	 * descriptor
256 	 *
257 	 * 0. entry point
258 	 * 1. TOC value (r2)
259 	 * 2. Environment pointer (r11)
260 	 */
261 
262 	(void)copyin((void *)imgp->entry_addr, entry_desc,
263 	    sizeof(entry_desc));
264 	tf->srr0 = entry_desc[0] + imgp->reloc_base;
265 	tf->fixreg[2] = entry_desc[1] + imgp->reloc_base;
266 	tf->fixreg[11] = entry_desc[2] + imgp->reloc_base;
267 }
268 
269 void
elf64_dump_thread(struct thread * td,void * dst,size_t * off)270 elf64_dump_thread(struct thread *td, void *dst, size_t *off)
271 {
272 	size_t len;
273 	struct pcb *pcb;
274 	uint64_t vshr[32];
275 	uint64_t *vsr_dw1;
276 	int vsr_idx;
277 
278 	len = 0;
279 	pcb = td->td_pcb;
280 
281 	if (pcb->pcb_flags & PCB_VEC) {
282 		if (dst != NULL) {
283 			len += elf64_populate_note(NT_PPC_VMX,
284 			    &pcb->pcb_vec, (char *)dst + len,
285 			    sizeof(pcb->pcb_vec), NULL);
286 		} else
287 			len += elf64_populate_note(NT_PPC_VMX, NULL, NULL,
288 			    sizeof(pcb->pcb_vec), NULL);
289 	}
290 
291 	if (pcb->pcb_flags & PCB_VSX) {
292 		if (dst != NULL) {
293 			/*
294 			 * Doubleword 0 of VSR0-VSR31 overlap with FPR0-FPR31 and
295 			 * VSR32-VSR63 overlap with VR0-VR31, so we only copy
296 			 * the non-overlapping data, which is doubleword 1 of VSR0-VSR31.
297 			 */
298 			for (vsr_idx = 0; vsr_idx < nitems(vshr); vsr_idx++) {
299 				vsr_dw1 = (uint64_t *)&pcb->pcb_fpu.fpr[vsr_idx].vsr[2];
300 				vshr[vsr_idx] = *vsr_dw1;
301 			}
302 			len += elf64_populate_note(NT_PPC_VSX,
303 			    vshr, (char *)dst + len,
304 			    sizeof(vshr), NULL);
305 		} else
306 			len += elf64_populate_note(NT_PPC_VSX, NULL, NULL,
307 			    sizeof(vshr), NULL);
308 	}
309 
310 	*off = len;
311 }
312 
313 bool
elf_is_ifunc_reloc(Elf_Size r_info)314 elf_is_ifunc_reloc(Elf_Size r_info)
315 {
316 
317 	return (ELF_R_TYPE(r_info) == R_PPC_IRELATIVE);
318 }
319 
320 /* Process one elf relocation with addend. */
321 static int
elf_reloc_internal(linker_file_t lf,Elf_Addr relocbase,const void * data,int type,int local,elf_lookup_fn lookup)322 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data,
323     int type, int local, elf_lookup_fn lookup)
324 {
325 	Elf_Addr *where;
326 	Elf_Addr addr;
327 	Elf_Addr addend, val;
328 	Elf_Word rtype, symidx;
329 	const Elf_Rela *rela;
330 	int error;
331 
332 	switch (type) {
333 	case ELF_RELOC_REL:
334 		panic("PPC only supports RELA relocations");
335 		break;
336 	case ELF_RELOC_RELA:
337 		rela = (const Elf_Rela *)data;
338 		where = (Elf_Addr *) (relocbase + rela->r_offset);
339 		addend = rela->r_addend;
340 		rtype = ELF_R_TYPE(rela->r_info);
341 		symidx = ELF_R_SYM(rela->r_info);
342 		break;
343 	default:
344 		panic("elf_reloc: unknown relocation mode %d\n", type);
345 	}
346 
347 	switch (rtype) {
348 	case R_PPC_NONE:
349 		break;
350 
351 	case R_PPC64_ADDR64:	/* doubleword64 S + A */
352 		error = lookup(lf, symidx, 1, &addr);
353 		if (error != 0)
354 			return (-1);
355 		addr += addend;
356 		*where = addr;
357 		break;
358 
359 	case R_PPC_RELATIVE:	/* doubleword64 B + A */
360 		*where = elf_relocaddr(lf, relocbase + addend);
361 		break;
362 
363 	case R_PPC_JMP_SLOT:	/* function descriptor copy */
364 		lookup(lf, symidx, 1, &addr);
365 #if !defined(_CALL_ELF) || _CALL_ELF == 1
366 		memcpy(where, (Elf_Addr *)addr, 3*sizeof(Elf_Addr));
367 #else
368 		*where = addr;
369 #endif
370 		__asm __volatile("dcbst 0,%0; sync" :: "r"(where) : "memory");
371 		break;
372 
373 	case R_PPC_IRELATIVE:
374 		addr = relocbase + addend;
375 		val = ((Elf64_Addr (*)(void))addr)();
376 		if (*where != val)
377 			*where = val;
378 		break;
379 
380 	default:
381 		printf("kldload: unexpected relocation type %d, "
382 		    "symbol index %d\n", (int)rtype, symidx);
383 		return (-1);
384 	}
385 	return (0);
386 }
387 
388 void
elf_reloc_self(Elf_Dyn * dynp,Elf_Addr relocbase)389 elf_reloc_self(Elf_Dyn *dynp, Elf_Addr relocbase)
390 {
391 	Elf_Rela *rela = NULL, *relalim;
392 	Elf_Addr relasz = 0;
393 	Elf_Addr *where;
394 
395 	/*
396 	 * Extract the rela/relasz values from the dynamic section
397 	 */
398 	for (; dynp->d_tag != DT_NULL; dynp++) {
399 		switch (dynp->d_tag) {
400 		case DT_RELA:
401 			rela = (Elf_Rela *)(relocbase+dynp->d_un.d_ptr);
402 			break;
403 		case DT_RELASZ:
404 			relasz = dynp->d_un.d_val;
405 			break;
406 		}
407 	}
408 
409 	/*
410 	 * Relocate these values
411 	 */
412 	relalim = (Elf_Rela *)((caddr_t)rela + relasz);
413 	for (; rela < relalim; rela++) {
414 		if (ELF_R_TYPE(rela->r_info) != R_PPC_RELATIVE)
415 			continue;
416 		where = (Elf_Addr *)(relocbase + rela->r_offset);
417 		*where = (Elf_Addr)(relocbase + rela->r_addend);
418 	}
419 }
420 
421 int
elf_reloc(linker_file_t lf,Elf_Addr relocbase,const void * data,int type,elf_lookup_fn lookup)422 elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type,
423     elf_lookup_fn lookup)
424 {
425 
426 	return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup));
427 }
428 
429 int
elf_reloc_local(linker_file_t lf,Elf_Addr relocbase,const void * data,int type,elf_lookup_fn lookup)430 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data,
431     int type, elf_lookup_fn lookup)
432 {
433 
434 	return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup));
435 }
436 
437 int
elf_cpu_load_file(linker_file_t lf)438 elf_cpu_load_file(linker_file_t lf)
439 {
440 	/* Only sync the cache for non-kernel modules */
441 	if (lf->id != 1)
442 		__syncicache(lf->address, lf->size);
443 	return (0);
444 }
445 
446 int
elf_cpu_unload_file(linker_file_t lf __unused)447 elf_cpu_unload_file(linker_file_t lf __unused)
448 {
449 
450 	return (0);
451 }
452 
453 int
elf_cpu_parse_dynamic(caddr_t loadbase __unused,Elf_Dyn * dynamic __unused)454 elf_cpu_parse_dynamic(caddr_t loadbase __unused, Elf_Dyn *dynamic __unused)
455 {
456 
457 	return (0);
458 }
459