xref: /freebsd/sys/powerpc/powerpc/elf32_machdep.c (revision 0957b409)
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 
34 #define __ELF_WORD_SIZE 32
35 
36 #include <sys/exec.h>
37 #include <sys/imgact.h>
38 #include <sys/malloc.h>
39 #include <sys/proc.h>
40 #include <sys/namei.h>
41 #include <sys/fcntl.h>
42 #include <sys/sysent.h>
43 #include <sys/imgact_elf.h>
44 #include <sys/syscall.h>
45 #include <sys/sysctl.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 
53 #include <machine/altivec.h>
54 #include <machine/cpu.h>
55 #include <machine/fpu.h>
56 #include <machine/elf.h>
57 #include <machine/reg.h>
58 #include <machine/md_var.h>
59 
60 #ifdef __powerpc64__
61 #include <compat/freebsd32/freebsd32_proto.h>
62 #include <compat/freebsd32/freebsd32_util.h>
63 
64 extern const char *freebsd32_syscallnames[];
65 static void ppc32_fixlimit(struct rlimit *rl, int which);
66 
67 static SYSCTL_NODE(_compat, OID_AUTO, ppc32, CTLFLAG_RW, 0, "32-bit mode");
68 
69 #define PPC32_MAXDSIZ (1024*1024*1024)
70 static u_long ppc32_maxdsiz = PPC32_MAXDSIZ;
71 SYSCTL_ULONG(_compat_ppc32, OID_AUTO, maxdsiz, CTLFLAG_RWTUN, &ppc32_maxdsiz,
72              0, "");
73 #define PPC32_MAXSSIZ (64*1024*1024)
74 u_long ppc32_maxssiz = PPC32_MAXSSIZ;
75 SYSCTL_ULONG(_compat_ppc32, OID_AUTO, maxssiz, CTLFLAG_RWTUN, &ppc32_maxssiz,
76              0, "");
77 #endif
78 
79 struct sysentvec elf32_freebsd_sysvec = {
80 	.sv_size	= SYS_MAXSYSCALL,
81 #ifdef __powerpc64__
82 	.sv_table	= freebsd32_sysent,
83 #else
84 	.sv_table	= sysent,
85 #endif
86 	.sv_errsize	= 0,
87 	.sv_errtbl	= NULL,
88 	.sv_transtrap	= NULL,
89 	.sv_fixup	= __elfN(freebsd_fixup),
90 	.sv_sendsig	= sendsig,
91 	.sv_sigcode	= sigcode32,
92 	.sv_szsigcode	= &szsigcode32,
93 	.sv_name	= "FreeBSD ELF32",
94 	.sv_coredump	= __elfN(coredump),
95 	.sv_imgact_try	= NULL,
96 	.sv_minsigstksz	= MINSIGSTKSZ,
97 	.sv_pagesize	= PAGE_SIZE,
98 	.sv_minuser	= VM_MIN_ADDRESS,
99 	.sv_stackprot	= VM_PROT_ALL,
100 #ifdef __powerpc64__
101 	.sv_maxuser	= VM_MAXUSER_ADDRESS,
102 	.sv_usrstack	= FREEBSD32_USRSTACK,
103 	.sv_psstrings	= FREEBSD32_PS_STRINGS,
104 	.sv_copyout_strings = freebsd32_copyout_strings,
105 	.sv_setregs	= ppc32_setregs,
106 	.sv_syscallnames = freebsd32_syscallnames,
107 	.sv_fixlimit	= ppc32_fixlimit,
108 #else
109 	.sv_maxuser	= VM_MAXUSER_ADDRESS,
110 	.sv_usrstack	= USRSTACK,
111 	.sv_psstrings	= PS_STRINGS,
112 	.sv_copyout_strings = exec_copyout_strings,
113 	.sv_setregs	= exec_setregs,
114 	.sv_syscallnames = syscallnames,
115 	.sv_fixlimit	= NULL,
116 #endif
117 	.sv_maxssiz	= NULL,
118 	.sv_flags	= SV_ABI_FREEBSD | SV_ILP32 | SV_SHP | SV_ASLR,
119 	.sv_set_syscall_retval = cpu_set_syscall_retval,
120 	.sv_fetch_syscall_args = cpu_fetch_syscall_args,
121 	.sv_shared_page_base = FREEBSD32_SHAREDPAGE,
122 	.sv_shared_page_len = PAGE_SIZE,
123 	.sv_schedtail	= NULL,
124 	.sv_thread_detach = NULL,
125 	.sv_trap	= NULL,
126 	.sv_hwcap	= &cpu_features,
127 	.sv_hwcap2	= &cpu_features2,
128 };
129 INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec);
130 
131 static Elf32_Brandinfo freebsd_brand_info = {
132 	.brand		= ELFOSABI_FREEBSD,
133 	.machine	= EM_PPC,
134 	.compat_3_brand	= "FreeBSD",
135 	.emul_path	= NULL,
136 	.interp_path	= "/libexec/ld-elf.so.1",
137 	.sysvec		= &elf32_freebsd_sysvec,
138 #ifdef __powerpc64__
139 	.interp_newpath	= "/libexec/ld-elf32.so.1",
140 #else
141 	.interp_newpath	= NULL,
142 #endif
143 	.brand_note	= &elf32_freebsd_brandnote,
144 	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
145 };
146 
147 SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST,
148     (sysinit_cfunc_t) elf32_insert_brand_entry,
149     &freebsd_brand_info);
150 
151 static Elf32_Brandinfo freebsd_brand_oinfo = {
152 	.brand		= ELFOSABI_FREEBSD,
153 	.machine	= EM_PPC,
154 	.compat_3_brand	= "FreeBSD",
155 	.emul_path	= NULL,
156 	.interp_path	= "/usr/libexec/ld-elf.so.1",
157 	.sysvec		= &elf32_freebsd_sysvec,
158 	.interp_newpath	= NULL,
159 	.brand_note	= &elf32_freebsd_brandnote,
160 	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
161 };
162 
163 SYSINIT(oelf32, SI_SUB_EXEC, SI_ORDER_ANY,
164 	(sysinit_cfunc_t) elf32_insert_brand_entry,
165 	&freebsd_brand_oinfo);
166 
167 void elf_reloc_self(Elf_Dyn *dynp, Elf_Addr relocbase);
168 
169 void
170 elf32_dump_thread(struct thread *td, void *dst, size_t *off)
171 {
172 	size_t len;
173 	struct pcb *pcb;
174 	uint64_t vshr[32];
175 	uint64_t *vsr_dw1;
176 	int vsr_idx;
177 
178 	len = 0;
179 	pcb = td->td_pcb;
180 
181 	if (pcb->pcb_flags & PCB_VEC) {
182 		save_vec_nodrop(td);
183 		if (dst != NULL) {
184 			len += elf32_populate_note(NT_PPC_VMX,
185 			    &pcb->pcb_vec, (char *)dst + len,
186 			    sizeof(pcb->pcb_vec), NULL);
187 		} else
188 			len += elf32_populate_note(NT_PPC_VMX, NULL, NULL,
189 			    sizeof(pcb->pcb_vec), NULL);
190 	}
191 
192 	if (pcb->pcb_flags & PCB_VSX) {
193 		save_fpu_nodrop(td);
194 		if (dst != NULL) {
195 			/*
196 			 * Doubleword 0 of VSR0-VSR31 overlap with FPR0-FPR31 and
197 			 * VSR32-VSR63 overlap with VR0-VR31, so we only copy
198 			 * the non-overlapping data, which is doubleword 1 of VSR0-VSR31.
199 			 */
200 			for (vsr_idx = 0; vsr_idx < nitems(vshr); vsr_idx++) {
201 				vsr_dw1 = (uint64_t *)&pcb->pcb_fpu.fpr[vsr_idx].vsr[2];
202 				vshr[vsr_idx] = *vsr_dw1;
203 			}
204 			len += elf32_populate_note(NT_PPC_VSX,
205 			    vshr, (char *)dst + len,
206 			    sizeof(vshr), NULL);
207 		} else
208 			len += elf32_populate_note(NT_PPC_VSX, NULL, NULL,
209 			    sizeof(vshr), NULL);
210 	}
211 
212 	*off = len;
213 }
214 
215 #ifndef __powerpc64__
216 bool
217 elf_is_ifunc_reloc(Elf_Size r_info __unused)
218 {
219 
220 	return (false);
221 }
222 
223 /* Process one elf relocation with addend. */
224 static int
225 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data,
226     int type, int local, elf_lookup_fn lookup)
227 {
228 	Elf_Addr *where;
229 	Elf_Half *hwhere;
230 	Elf_Addr addr;
231 	Elf_Addr addend;
232 	Elf_Word rtype, symidx;
233 	const Elf_Rela *rela;
234 	int error;
235 
236 	switch (type) {
237 	case ELF_RELOC_REL:
238 		panic("PPC only supports RELA relocations");
239 		break;
240 	case ELF_RELOC_RELA:
241 		rela = (const Elf_Rela *)data;
242 		where = (Elf_Addr *) ((uintptr_t)relocbase + rela->r_offset);
243 		hwhere = (Elf_Half *) ((uintptr_t)relocbase + rela->r_offset);
244 		addend = rela->r_addend;
245 		rtype = ELF_R_TYPE(rela->r_info);
246 		symidx = ELF_R_SYM(rela->r_info);
247 		break;
248 	default:
249 		panic("elf_reloc: unknown relocation mode %d\n", type);
250 	}
251 
252 	switch (rtype) {
253 
254 	case R_PPC_NONE:
255 		break;
256 
257 	case R_PPC_ADDR32: /* word32 S + A */
258 		error = lookup(lf, symidx, 1, &addr);
259 		if (error != 0)
260 			return -1;
261 		*where = elf_relocaddr(lf, addr + addend);
262 			break;
263 
264 	case R_PPC_ADDR16_LO: /* #lo(S) */
265 		error = lookup(lf, symidx, 1, &addr);
266 		if (error != 0)
267 			return -1;
268 		/*
269 		 * addend values are sometimes relative to sections
270 		 * (i.e. .rodata) in rela, where in reality they
271 		 * are relative to relocbase. Detect this condition.
272 		 */
273 		if (addr > relocbase && addr <= (relocbase + addend))
274 			addr = relocbase;
275 		addr = elf_relocaddr(lf, addr + addend);
276 		*hwhere = addr & 0xffff;
277 		break;
278 
279 	case R_PPC_ADDR16_HA: /* #ha(S) */
280 		error = lookup(lf, symidx, 1, &addr);
281 		if (error != 0)
282 			return -1;
283 		/*
284 		 * addend values are sometimes relative to sections
285 		 * (i.e. .rodata) in rela, where in reality they
286 		 * are relative to relocbase. Detect this condition.
287 		 */
288 		if (addr > relocbase && addr <= (relocbase + addend))
289 			addr = relocbase;
290 		addr = elf_relocaddr(lf, addr + addend);
291 		*hwhere = ((addr >> 16) + ((addr & 0x8000) ? 1 : 0))
292 		    & 0xffff;
293 		break;
294 
295 	case R_PPC_RELATIVE: /* word32 B + A */
296 		*where = elf_relocaddr(lf, relocbase + addend);
297 		break;
298 
299 	default:
300 		printf("kldload: unexpected relocation type %d\n",
301 		    (int) rtype);
302 		return -1;
303 	}
304 	return(0);
305 }
306 
307 void
308 elf_reloc_self(Elf_Dyn *dynp, Elf_Addr relocbase)
309 {
310 	Elf_Rela *rela = NULL, *relalim;
311 	Elf_Addr relasz = 0;
312 	Elf_Addr *where;
313 
314 	/*
315 	 * Extract the rela/relasz values from the dynamic section
316 	 */
317 	for (; dynp->d_tag != DT_NULL; dynp++) {
318 		switch (dynp->d_tag) {
319 		case DT_RELA:
320 			rela = (Elf_Rela *)(relocbase+dynp->d_un.d_ptr);
321 			break;
322 		case DT_RELASZ:
323 			relasz = dynp->d_un.d_val;
324 			break;
325 		}
326 	}
327 
328 	/*
329 	 * Relocate these values
330 	 */
331 	relalim = (Elf_Rela *)((caddr_t)rela + relasz);
332 	for (; rela < relalim; rela++) {
333 		if (ELF_R_TYPE(rela->r_info) != R_PPC_RELATIVE)
334 			continue;
335 		where = (Elf_Addr *)(relocbase + rela->r_offset);
336 		*where = (Elf_Addr)(relocbase + rela->r_addend);
337 	}
338 }
339 
340 int
341 elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type,
342     elf_lookup_fn lookup)
343 {
344 
345 	return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup));
346 }
347 
348 int
349 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data,
350     int type, elf_lookup_fn lookup)
351 {
352 
353 	return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup));
354 }
355 
356 int
357 elf_cpu_load_file(linker_file_t lf)
358 {
359 	/* Only sync the cache for non-kernel modules */
360 	if (lf->id != 1)
361 		__syncicache(lf->address, lf->size);
362 	return (0);
363 }
364 
365 int
366 elf_cpu_unload_file(linker_file_t lf __unused)
367 {
368 
369 	return (0);
370 }
371 #endif
372 
373 #ifdef __powerpc64__
374 static void
375 ppc32_fixlimit(struct rlimit *rl, int which)
376 {
377 	switch (which) {
378 	case RLIMIT_DATA:
379 		if (ppc32_maxdsiz != 0) {
380 			if (rl->rlim_cur > ppc32_maxdsiz)
381 				rl->rlim_cur = ppc32_maxdsiz;
382 			if (rl->rlim_max > ppc32_maxdsiz)
383 				rl->rlim_max = ppc32_maxdsiz;
384 		}
385 		break;
386 	case RLIMIT_STACK:
387 		if (ppc32_maxssiz != 0) {
388 			if (rl->rlim_cur > ppc32_maxssiz)
389 				rl->rlim_cur = ppc32_maxssiz;
390 			if (rl->rlim_max > ppc32_maxssiz)
391 				rl->rlim_max = ppc32_maxssiz;
392 		}
393 		break;
394 	}
395 }
396 #endif
397