1/*	$NetBSD: kobj_machdep.c,v 1.16 2023/04/28 07:33:56 skrll Exp $	*/
2
3/*-
4 * Copyright (c) 2008 The NetBSD Foundation, Inc.
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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/*-
30 * Copyright 1996-1998 John D. Polstra.
31 * All rights reserved.
32 *
33 * Redistribution and use in source and binary forms, with or without
34 * modification, are permitted provided that the following conditions
35 * are met:
36 * 1. Redistributions of source code must retain the above copyright
37 *    notice, this list of conditions and the following disclaimer.
38 * 2. Redistributions in binary form must reproduce the above copyright
39 *    notice, this list of conditions and the following disclaimer in the
40 *    documentation and/or other materials provided with the distribution.
41 *
42 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
43 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
44 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
45 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
46 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
47 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
48 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
49 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
50 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
51 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
52 */
53
54#include <sys/cdefs.h>
55__KERNEL_RCSID(0, "$NetBSD: kobj_machdep.c,v 1.16 2023/04/28 07:33:56 skrll Exp $");
56
57#define	ELFSIZE		ARCH_ELFSIZE
58
59#include <sys/param.h>
60
61#include <sys/exec.h>
62#include <sys/exec_elf.h>
63#include <sys/kmem.h>
64#include <sys/kobj.h>
65#include <sys/kobj_impl.h>
66#include <sys/ksyms.h>
67#include <sys/systm.h>
68
69#include <arm/cpufunc.h>
70#include <arm/locore.h>
71
72int
73kobj_reloc(kobj_t ko, uintptr_t relocbase, const void *data,
74	   bool isrela, bool local)
75{
76	Elf_Addr *where;
77	Elf_Addr addr;
78	Elf_Addr addend;
79	Elf_Word rtype, symidx;
80	const Elf_Rel *rel;
81	const Elf_Rela *rela;
82	int error;
83
84	if (isrela) {
85		rela = (const Elf_Rela *)data;
86		where = (Elf_Addr *) (relocbase + rela->r_offset);
87		addend = rela->r_addend;
88		rtype = ELF_R_TYPE(rela->r_info);
89		symidx = ELF_R_SYM(rela->r_info);
90	} else {
91		rel = (const Elf_Rel *)data;
92		where = (Elf_Addr *) (relocbase + rel->r_offset);
93		addend = *where;
94		rtype = ELF_R_TYPE(rel->r_info);
95		symidx = ELF_R_SYM(rel->r_info);
96	}
97
98	const Elf_Sym *sym = kobj_symbol(ko, symidx);
99
100	if (!local && ELF_ST_BIND(sym->st_info) == STB_LOCAL) {
101		return 0;
102	}
103
104	switch (rtype) {
105	case R_ARM_NONE:	/* none */
106	case R_ARM_V4BX:	/* none */
107		return 0;
108
109	case R_ARM_ABS32:
110		error = kobj_sym_lookup(ko, symidx, &addr);
111		if (error)
112			break;
113		*where = addr + addend;
114		return 0;
115
116	case R_ARM_COPY:	/* none */
117		/* There shouldn't be copy relocations in kernel objects. */
118		break;
119
120	case R_ARM_JUMP_SLOT:
121		error = kobj_sym_lookup(ko, symidx, &addr);
122		if (error)
123			break;
124		*where = addr;
125		return 0;
126
127	case R_ARM_RELATIVE:	/* A + B */
128		addr = relocbase + addend;
129		if (*where != addr)
130			*where = addr;
131		return 0;
132
133	case R_ARM_MOVW_ABS_NC:	/* (S + A) | T */
134	case R_ARM_MOVT_ABS:
135		if ((*where & 0x0fb00000) != 0x03000000)
136			break;
137		error = kobj_sym_lookup(ko, symidx, &addr);
138		if (error)
139			break;
140		if (rtype == R_ARM_MOVT_ABS)
141			addr >>= 16;
142		*where = (*where & 0xfff0f000)
143		    | ((addr << 4) & 0x000f0000) | (addr & 0x00000fff);
144		return 0;
145
146	case R_ARM_CALL:	/* ((S + A) | T) -  P */
147	case R_ARM_JUMP24:
148	case R_ARM_PC24:	/* Deprecated */
149		if (local && (*where & 0x00ffffff) != 0x00fffffe)
150			return 0;
151
152		/* Remove the instruction from the 24 bit offset */
153		addend &= 0x00ffffff;
154
155		/* Sign extend if necessary */
156		if (addend & 0x00800000)
157			addend |= 0xff000000;
158
159		addend <<= 2;
160
161		error = kobj_sym_lookup(ko, symidx, &addr);
162		if (error)
163			break;
164
165		addend += (uintptr_t)addr - (uintptr_t)where;
166
167		if (addend & 3) {
168			printf ("Relocation %x unaligned @ %p\n", addend, where);
169			return -1;
170		}
171
172		if ((addend & 0xfe000000) != 0x00000000 &&
173		    (addend & 0xfe000000) != 0xfe000000) {
174			printf ("Relocation %x too far @ %p\n", addend, where);
175			return -1;
176		}
177		*where = (*where & 0xff000000) | ((addend >> 2) & 0x00ffffff);
178		return 0;
179
180	case R_ARM_REL32:	/* ((S + A) | T) -  P */
181		/* T = 0 for now */
182		error = kobj_sym_lookup(ko, symidx, &addr);
183		if (error)
184			break;
185
186		addend += (uintptr_t)addr - (uintptr_t)where;
187		*where = addend;
188		return 0;
189
190	case R_ARM_PREL31:	/* ((S + A) | T) -  P */
191		/* Sign extend if necessary */
192		if (addend & 0x40000000)
193			addend |= 0xc0000000;
194		/* T = 0 for now */
195		error = kobj_sym_lookup(ko, symidx, &addr);
196		if (error)
197			break;
198
199		addend += (uintptr_t)addr - (uintptr_t)where;
200
201		if ((addend & 0x80000000) != 0x00000000 &&
202		    (addend & 0x80000000) != 0x80000000) {
203			printf ("Relocation %x too far @ %p\n", addend, where);
204			return -1;
205		}
206
207		*where = (*where & 0x80000000) | (addend & 0x7fffffff);
208
209	default:
210		break;
211	}
212
213	printf("kobj_reloc: unexpected/invalid relocation type %d @ %p symidx %u\n",
214	    rtype, where, symidx);
215	return -1;
216}
217
218#ifdef _ARM_ARCH_BE8
219
220enum be8_magic_sym_type {
221	Other, ArmStart, ThumbStart, DataStart
222};
223
224struct be8_marker {
225	enum be8_magic_sym_type type;
226	void *addr;
227};
228
229struct be8_marker_list {
230	size_t cnt;
231	struct be8_marker *markers;
232};
233
234/*
235 * See ELF for the ARM Architecture, Section 4.5.5: Mapping Symbols
236 * ARM reserves $a/$d/$t (and variants like $a.2) to mark start of
237 * arm/thumb code sections to allow conversion from ARM32-EB to -BE8
238 * format.
239 */
240static enum be8_magic_sym_type
241be8_sym_type(const char *name, int info)
242{
243	if (ELF_ST_BIND(info) != STB_LOCAL)
244		return Other;
245	if (ELF_ST_TYPE(info) != STT_NOTYPE)
246		return Other;
247	if (name[0] != '$' || name[1] == '\0' ||
248	    (name[2] != '\0' && name[2] != '.'))
249		return Other;
250
251	switch (name[1]) {
252	case 'a':
253		return ArmStart;
254	case 'd':
255		return DataStart;
256	case 't':
257		return ThumbStart;
258	default:
259		return Other;
260	}
261}
262
263static int
264be8_ksym_count(const char *name, int symindex, void *value, uint32_t size,
265	int info, void *cookie)
266{
267	size_t *res = cookie;
268	enum be8_magic_sym_type t = be8_sym_type(name, info);
269
270	if (t != Other)
271		(*res)++;
272	return 0;
273}
274
275static int
276be8_ksym_add(const char *name, int symindex, void *value, uint32_t size,
277	int info, void *cookie)
278{
279	size_t ndx;
280	struct be8_marker_list *list = cookie;
281	enum be8_magic_sym_type t = be8_sym_type(name, info);
282
283	if (t == Other)
284		return 0;
285
286	ndx = list->cnt++;
287	list->markers[ndx].type = t;
288	list->markers[ndx].addr = value;
289
290	return 0;
291}
292
293static int
294be8_ksym_comp(const void *a, const void *b)
295{
296	const struct be8_marker *ma = a, *mb = b;
297	uintptr_t va = (uintptr_t)ma->addr, vb = (uintptr_t)mb->addr;
298
299	if (va == vb)
300		return 0;
301	if (va < vb)
302		return -1;
303	return 1;
304}
305
306static void
307be8_ksym_swap(void *start, size_t size, const struct be8_marker_list *list)
308{
309	uintptr_t va_end = (uintptr_t)start + size;
310	size_t i;
311	uint32_t *p32, *p32_end, v32;
312	uint16_t *p16, *p16_end, v16;
313
314	/* find first relevant list entry */
315	for (i = 0; i < list->cnt; i++)
316		if (start <= list->markers[i].addr)
317			break;
318
319	/* swap all arm and thumb code parts of this section */
320	for ( ; i < list->cnt; i++) {
321		switch (list->markers[i].type) {
322		case ArmStart:
323			p32 = (uint32_t*)list->markers[i].addr;
324			p32_end = (uint32_t*)va_end;
325			if (i+1 < list->cnt) {
326				if ((uintptr_t)list->markers[i+1].addr
327				    < va_end)
328					p32_end = (uint32_t*)
329						list->markers[i+1].addr;
330			}
331			while (p32 < p32_end) {
332				v32 = bswap32(*p32);
333				*p32++ = v32;
334			}
335			break;
336		case ThumbStart:
337			p16 = (uint16_t*)list->markers[i].addr;
338			p16_end = (uint16_t*)va_end;
339			if (i+1 < list->cnt) {
340				if ((uintptr_t)list->markers[i+1].addr
341				    < va_end)
342					p16_end = (uint16_t*)
343						list->markers[i+1].addr;
344			}
345			while (p16 < p16_end) {
346				v16 = bswap16(*p16);
347				*p16++ = v16;
348			}
349			break;
350		default:
351			break;
352		}
353	}
354}
355
356static void
357kobj_be8_fixup(kobj_t ko)
358{
359	size_t relsym_cnt = 0, i, msize;
360	struct be8_marker_list list;
361	struct be8_marker tmp;
362
363	/*
364	 * Count all special relocations symbols
365	 */
366	ksyms_mod_foreach(ko->ko_name, be8_ksym_count, &relsym_cnt);
367
368	/*
369	 * Provide storage for the address list and add the symbols
370	 */
371	list.cnt = 0;
372	msize = relsym_cnt*sizeof(*list.markers);
373	list.markers = kmem_alloc(msize, KM_SLEEP);
374	ksyms_mod_foreach(ko->ko_name, be8_ksym_add, &list);
375	KASSERT(list.cnt == relsym_cnt);
376
377	/*
378	 * Sort symbols by ascending address
379	 */
380	if (kheapsort(list.markers, relsym_cnt, sizeof(*list.markers),
381	    be8_ksym_comp, &tmp) != 0)
382		panic("could not sort be8 marker symbols");
383
384	/*
385	 * Apply swaps to the .text section (XXX we do not have the
386	 * section header available any more, it has been jetisoned
387	 * already, so we can not check for all PROGBIT sections).
388	 */
389	for (i = 0; i < ko->ko_nprogtab; i++) {
390		if (strcmp(ko->ko_progtab[i].name, ".text") != 0)
391			continue;
392		be8_ksym_swap(ko->ko_progtab[i].addr,
393		    (size_t)ko->ko_progtab[i].size,
394		    &list);
395	}
396
397	/*
398	 * Done, free list
399	 */
400	kmem_free(list.markers, msize);
401}
402#endif
403
404int
405kobj_machdep(kobj_t ko, void *base, size_t size, bool load)
406{
407
408	if (load) {
409#ifdef _ARM_ARCH_BE8
410		if (base == (void*)ko->ko_text_address)
411			kobj_be8_fixup(ko);
412#endif
413#ifndef _RUMPKERNEL
414		cpu_idcache_wbinv_range((vaddr_t)base, size);
415		cpu_tlb_flushID();
416#endif
417	}
418
419	return 0;
420}
421