1// SPDX-License-Identifier: GPL-2.0-or-later
2/*    Kernel dynamically loadable module help for PARISC.
3 *
4 *    The best reference for this stuff is probably the Processor-
5 *    Specific ELF Supplement for PA-RISC:
6 *        https://parisc.wiki.kernel.org/index.php/File:Elf-pa-hp.pdf
7 *
8 *    Linux/PA-RISC Project
9 *    Copyright (C) 2003 Randolph Chung <tausq at debian . org>
10 *    Copyright (C) 2008 Helge Deller <deller@gmx.de>
11 *
12 *    Notes:
13 *    - PLT stub handling
14 *      On 32bit (and sometimes 64bit) and with big kernel modules like xfs or
15 *      ipv6 the relocation types R_PARISC_PCREL17F and R_PARISC_PCREL22F may
16 *      fail to reach their PLT stub if we only create one big stub array for
17 *      all sections at the beginning of the core or init section.
18 *      Instead we now insert individual PLT stub entries directly in front of
19 *      of the code sections where the stubs are actually called.
20 *      This reduces the distance between the PCREL location and the stub entry
21 *      so that the relocations can be fulfilled.
22 *      While calculating the final layout of the kernel module in memory, the
23 *      kernel module loader calls arch_mod_section_prepend() to request the
24 *      to be reserved amount of memory in front of each individual section.
25 *
26 *    - SEGREL32 handling
27 *      We are not doing SEGREL32 handling correctly. According to the ABI, we
28 *      should do a value offset, like this:
29 *			if (in_init(me, (void *)val))
30 *				val -= (uint32_t)me->mem[MOD_INIT_TEXT].base;
31 *			else
32 *				val -= (uint32_t)me->mem[MOD_TEXT].base;
33 *	However, SEGREL32 is used only for PARISC unwind entries, and we want
34 *	those entries to have an absolute address, and not just an offset.
35 *
36 *	The unwind table mechanism has the ability to specify an offset for
37 *	the unwind table; however, because we split off the init functions into
38 *	a different piece of memory, it is not possible to do this using a
39 *	single offset. Instead, we use the above hack for now.
40 */
41
42#include <linux/moduleloader.h>
43#include <linux/elf.h>
44#include <linux/vmalloc.h>
45#include <linux/fs.h>
46#include <linux/ftrace.h>
47#include <linux/string.h>
48#include <linux/kernel.h>
49#include <linux/bug.h>
50#include <linux/mm.h>
51#include <linux/slab.h>
52
53#include <asm/unwind.h>
54#include <asm/sections.h>
55
56#define RELOC_REACHABLE(val, bits) \
57	(( ( !((val) & (1<<((bits)-1))) && ((val)>>(bits)) != 0 )  ||	\
58	     ( ((val) & (1<<((bits)-1))) && ((val)>>(bits)) != (((__typeof__(val))(~0))>>((bits)+2)))) ? \
59	0 : 1)
60
61#define CHECK_RELOC(val, bits) \
62	if (!RELOC_REACHABLE(val, bits)) { \
63		printk(KERN_ERR "module %s relocation of symbol %s is out of range (0x%lx in %d bits)\n", \
64		me->name, strtab + sym->st_name, (unsigned long)val, bits); \
65		return -ENOEXEC;			\
66	}
67
68/* Maximum number of GOT entries. We use a long displacement ldd from
69 * the bottom of the table, which has a maximum signed displacement of
70 * 0x3fff; however, since we're only going forward, this becomes
71 * 0x1fff, and thus, since each GOT entry is 8 bytes long we can have
72 * at most 1023 entries.
73 * To overcome this 14bit displacement with some kernel modules, we'll
74 * use instead the unusal 16bit displacement method (see reassemble_16a)
75 * which gives us a maximum positive displacement of 0x7fff, and as such
76 * allows us to allocate up to 4095 GOT entries. */
77#define MAX_GOTS	4095
78
79#ifndef CONFIG_64BIT
80struct got_entry {
81	Elf32_Addr addr;
82};
83
84struct stub_entry {
85	Elf32_Word insns[2]; /* each stub entry has two insns */
86};
87#else
88struct got_entry {
89	Elf64_Addr addr;
90};
91
92struct stub_entry {
93	Elf64_Word insns[4]; /* each stub entry has four insns */
94};
95#endif
96
97/* Field selection types defined by hppa */
98#define rnd(x)			(((x)+0x1000)&~0x1fff)
99/* fsel: full 32 bits */
100#define fsel(v,a)		((v)+(a))
101/* lsel: select left 21 bits */
102#define lsel(v,a)		(((v)+(a))>>11)
103/* rsel: select right 11 bits */
104#define rsel(v,a)		(((v)+(a))&0x7ff)
105/* lrsel with rounding of addend to nearest 8k */
106#define lrsel(v,a)		(((v)+rnd(a))>>11)
107/* rrsel with rounding of addend to nearest 8k */
108#define rrsel(v,a)		((((v)+rnd(a))&0x7ff)+((a)-rnd(a)))
109
110#define mask(x,sz)		((x) & ~((1<<(sz))-1))
111
112
113/* The reassemble_* functions prepare an immediate value for
114   insertion into an opcode. pa-risc uses all sorts of weird bitfields
115   in the instruction to hold the value.  */
116static inline int sign_unext(int x, int len)
117{
118	int len_ones;
119
120	len_ones = (1 << len) - 1;
121	return x & len_ones;
122}
123
124static inline int low_sign_unext(int x, int len)
125{
126	int sign, temp;
127
128	sign = (x >> (len-1)) & 1;
129	temp = sign_unext(x, len-1);
130	return (temp << 1) | sign;
131}
132
133static inline int reassemble_14(int as14)
134{
135	return (((as14 & 0x1fff) << 1) |
136		((as14 & 0x2000) >> 13));
137}
138
139static inline int reassemble_16a(int as16)
140{
141	int s, t;
142
143	/* Unusual 16-bit encoding, for wide mode only.  */
144	t = (as16 << 1) & 0xffff;
145	s = (as16 & 0x8000);
146	return (t ^ s ^ (s >> 1)) | (s >> 15);
147}
148
149
150static inline int reassemble_17(int as17)
151{
152	return (((as17 & 0x10000) >> 16) |
153		((as17 & 0x0f800) << 5) |
154		((as17 & 0x00400) >> 8) |
155		((as17 & 0x003ff) << 3));
156}
157
158static inline int reassemble_21(int as21)
159{
160	return (((as21 & 0x100000) >> 20) |
161		((as21 & 0x0ffe00) >> 8) |
162		((as21 & 0x000180) << 7) |
163		((as21 & 0x00007c) << 14) |
164		((as21 & 0x000003) << 12));
165}
166
167static inline int reassemble_22(int as22)
168{
169	return (((as22 & 0x200000) >> 21) |
170		((as22 & 0x1f0000) << 5) |
171		((as22 & 0x00f800) << 5) |
172		((as22 & 0x000400) >> 8) |
173		((as22 & 0x0003ff) << 3));
174}
175
176void *module_alloc(unsigned long size)
177{
178	/* using RWX means less protection for modules, but it's
179	 * easier than trying to map the text, data, init_text and
180	 * init_data correctly */
181	return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
182				    GFP_KERNEL,
183				    PAGE_KERNEL_RWX, 0, NUMA_NO_NODE,
184				    __builtin_return_address(0));
185}
186
187#ifndef CONFIG_64BIT
188static inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n)
189{
190	return 0;
191}
192
193static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n)
194{
195	return 0;
196}
197
198static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n)
199{
200	unsigned long cnt = 0;
201
202	for (; n > 0; n--, rela++)
203	{
204		switch (ELF32_R_TYPE(rela->r_info)) {
205			case R_PARISC_PCREL17F:
206			case R_PARISC_PCREL22F:
207				cnt++;
208		}
209	}
210
211	return cnt;
212}
213#else
214static inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n)
215{
216	unsigned long cnt = 0;
217
218	for (; n > 0; n--, rela++)
219	{
220		switch (ELF64_R_TYPE(rela->r_info)) {
221			case R_PARISC_LTOFF21L:
222			case R_PARISC_LTOFF14R:
223			case R_PARISC_PCREL22F:
224				cnt++;
225		}
226	}
227
228	return cnt;
229}
230
231static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n)
232{
233	unsigned long cnt = 0;
234
235	for (; n > 0; n--, rela++)
236	{
237		switch (ELF64_R_TYPE(rela->r_info)) {
238			case R_PARISC_FPTR64:
239				cnt++;
240		}
241	}
242
243	return cnt;
244}
245
246static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n)
247{
248	unsigned long cnt = 0;
249
250	for (; n > 0; n--, rela++)
251	{
252		switch (ELF64_R_TYPE(rela->r_info)) {
253			case R_PARISC_PCREL22F:
254				cnt++;
255		}
256	}
257
258	return cnt;
259}
260#endif
261
262void module_arch_freeing_init(struct module *mod)
263{
264	kfree(mod->arch.section);
265	mod->arch.section = NULL;
266}
267
268/* Additional bytes needed in front of individual sections */
269unsigned int arch_mod_section_prepend(struct module *mod,
270				      unsigned int section)
271{
272	/* size needed for all stubs of this section (including
273	 * one additional for correct alignment of the stubs) */
274	return (mod->arch.section[section].stub_entries + 1)
275		* sizeof(struct stub_entry);
276}
277
278#define CONST
279int module_frob_arch_sections(CONST Elf_Ehdr *hdr,
280			      CONST Elf_Shdr *sechdrs,
281			      CONST char *secstrings,
282			      struct module *me)
283{
284	unsigned long gots = 0, fdescs = 0, len;
285	unsigned int i;
286	struct module_memory *mod_mem;
287
288	len = hdr->e_shnum * sizeof(me->arch.section[0]);
289	me->arch.section = kzalloc(len, GFP_KERNEL);
290	if (!me->arch.section)
291		return -ENOMEM;
292
293	for (i = 1; i < hdr->e_shnum; i++) {
294		const Elf_Rela *rels = (void *)sechdrs[i].sh_addr;
295		unsigned long nrels = sechdrs[i].sh_size / sizeof(*rels);
296		unsigned int count, s;
297
298		if (strncmp(secstrings + sechdrs[i].sh_name,
299			    ".PARISC.unwind", 14) == 0)
300			me->arch.unwind_section = i;
301
302		if (sechdrs[i].sh_type != SHT_RELA)
303			continue;
304
305		/* some of these are not relevant for 32-bit/64-bit
306		 * we leave them here to make the code common. the
307		 * compiler will do its thing and optimize out the
308		 * stuff we don't need
309		 */
310		gots += count_gots(rels, nrels);
311		fdescs += count_fdescs(rels, nrels);
312
313		/* XXX: By sorting the relocs and finding duplicate entries
314		 *  we could reduce the number of necessary stubs and save
315		 *  some memory. */
316		count = count_stubs(rels, nrels);
317		if (!count)
318			continue;
319
320		/* so we need relocation stubs. reserve necessary memory. */
321		/* sh_info gives the section for which we need to add stubs. */
322		s = sechdrs[i].sh_info;
323
324		/* each code section should only have one relocation section */
325		WARN_ON(me->arch.section[s].stub_entries);
326
327		/* store number of stubs we need for this section */
328		me->arch.section[s].stub_entries += count;
329	}
330
331	mod_mem = &me->mem[MOD_TEXT];
332	/* align things a bit */
333	mod_mem->size = ALIGN(mod_mem->size, 16);
334	me->arch.got_offset = mod_mem->size;
335	mod_mem->size += gots * sizeof(struct got_entry);
336
337	mod_mem->size = ALIGN(mod_mem->size, 16);
338	me->arch.fdesc_offset = mod_mem->size;
339	mod_mem->size += fdescs * sizeof(Elf_Fdesc);
340
341	me->arch.got_max = gots;
342	me->arch.fdesc_max = fdescs;
343
344	return 0;
345}
346
347#ifdef CONFIG_64BIT
348static Elf64_Word get_got(struct module *me, unsigned long value, long addend)
349{
350	unsigned int i;
351	struct got_entry *got;
352
353	value += addend;
354
355	BUG_ON(value == 0);
356
357	got = me->mem[MOD_TEXT].base + me->arch.got_offset;
358	for (i = 0; got[i].addr; i++)
359		if (got[i].addr == value)
360			goto out;
361
362	BUG_ON(++me->arch.got_count > me->arch.got_max);
363
364	got[i].addr = value;
365 out:
366	pr_debug("GOT ENTRY %d[%lx] val %lx\n", i, i*sizeof(struct got_entry),
367	       value);
368	return i * sizeof(struct got_entry);
369}
370#endif /* CONFIG_64BIT */
371
372#ifdef CONFIG_64BIT
373static Elf_Addr get_fdesc(struct module *me, unsigned long value)
374{
375	Elf_Fdesc *fdesc = me->mem[MOD_TEXT].base + me->arch.fdesc_offset;
376
377	if (!value) {
378		printk(KERN_ERR "%s: zero OPD requested!\n", me->name);
379		return 0;
380	}
381
382	/* Look for existing fdesc entry. */
383	while (fdesc->addr) {
384		if (fdesc->addr == value)
385			return (Elf_Addr)fdesc;
386		fdesc++;
387	}
388
389	BUG_ON(++me->arch.fdesc_count > me->arch.fdesc_max);
390
391	/* Create new one */
392	fdesc->addr = value;
393	fdesc->gp = (Elf_Addr)me->mem[MOD_TEXT].base + me->arch.got_offset;
394	return (Elf_Addr)fdesc;
395}
396#endif /* CONFIG_64BIT */
397
398enum elf_stub_type {
399	ELF_STUB_GOT,
400	ELF_STUB_MILLI,
401	ELF_STUB_DIRECT,
402};
403
404static Elf_Addr get_stub(struct module *me, unsigned long value, long addend,
405	enum elf_stub_type stub_type, Elf_Addr loc0, unsigned int targetsec)
406{
407	struct stub_entry *stub;
408	int __maybe_unused d;
409
410	/* initialize stub_offset to point in front of the section */
411	if (!me->arch.section[targetsec].stub_offset) {
412		loc0 -= (me->arch.section[targetsec].stub_entries + 1) *
413				sizeof(struct stub_entry);
414		/* get correct alignment for the stubs */
415		loc0 = ALIGN(loc0, sizeof(struct stub_entry));
416		me->arch.section[targetsec].stub_offset = loc0;
417	}
418
419	/* get address of stub entry */
420	stub = (void *) me->arch.section[targetsec].stub_offset;
421	me->arch.section[targetsec].stub_offset += sizeof(struct stub_entry);
422
423	/* do not write outside available stub area */
424	BUG_ON(0 == me->arch.section[targetsec].stub_entries--);
425
426
427#ifndef CONFIG_64BIT
428/* for 32-bit the stub looks like this:
429 * 	ldil L'XXX,%r1
430 * 	be,n R'XXX(%sr4,%r1)
431 */
432	//value = *(unsigned long *)((value + addend) & ~3); /* why? */
433
434	stub->insns[0] = 0x20200000;	/* ldil L'XXX,%r1	*/
435	stub->insns[1] = 0xe0202002;	/* be,n R'XXX(%sr4,%r1)	*/
436
437	stub->insns[0] |= reassemble_21(lrsel(value, addend));
438	stub->insns[1] |= reassemble_17(rrsel(value, addend) / 4);
439
440#else
441/* for 64-bit we have three kinds of stubs:
442 * for normal function calls:
443 * 	ldd 0(%dp),%dp
444 * 	ldd 10(%dp), %r1
445 * 	bve (%r1)
446 * 	ldd 18(%dp), %dp
447 *
448 * for millicode:
449 * 	ldil 0, %r1
450 * 	ldo 0(%r1), %r1
451 * 	ldd 10(%r1), %r1
452 * 	bve,n (%r1)
453 *
454 * for direct branches (jumps between different section of the
455 * same module):
456 *	ldil 0, %r1
457 *	ldo 0(%r1), %r1
458 *	bve,n (%r1)
459 */
460	switch (stub_type) {
461	case ELF_STUB_GOT:
462		d = get_got(me, value, addend);
463		if (d <= 15) {
464			/* Format 5 */
465			stub->insns[0] = 0x0f6010db; /* ldd 0(%dp),%dp	*/
466			stub->insns[0] |= low_sign_unext(d, 5) << 16;
467		} else {
468			/* Format 3 */
469			stub->insns[0] = 0x537b0000; /* ldd 0(%dp),%dp	*/
470			stub->insns[0] |= reassemble_16a(d);
471		}
472		stub->insns[1] = 0x53610020;	/* ldd 10(%dp),%r1	*/
473		stub->insns[2] = 0xe820d000;	/* bve (%r1)		*/
474		stub->insns[3] = 0x537b0030;	/* ldd 18(%dp),%dp	*/
475		break;
476	case ELF_STUB_MILLI:
477		stub->insns[0] = 0x20200000;	/* ldil 0,%r1		*/
478		stub->insns[1] = 0x34210000;	/* ldo 0(%r1), %r1	*/
479		stub->insns[2] = 0x50210020;	/* ldd 10(%r1),%r1	*/
480		stub->insns[3] = 0xe820d002;	/* bve,n (%r1)		*/
481
482		stub->insns[0] |= reassemble_21(lrsel(value, addend));
483		stub->insns[1] |= reassemble_14(rrsel(value, addend));
484		break;
485	case ELF_STUB_DIRECT:
486		stub->insns[0] = 0x20200000;    /* ldil 0,%r1           */
487		stub->insns[1] = 0x34210000;    /* ldo 0(%r1), %r1      */
488		stub->insns[2] = 0xe820d002;    /* bve,n (%r1)          */
489
490		stub->insns[0] |= reassemble_21(lrsel(value, addend));
491		stub->insns[1] |= reassemble_14(rrsel(value, addend));
492		break;
493	}
494
495#endif
496
497	return (Elf_Addr)stub;
498}
499
500#ifndef CONFIG_64BIT
501int apply_relocate_add(Elf_Shdr *sechdrs,
502		       const char *strtab,
503		       unsigned int symindex,
504		       unsigned int relsec,
505		       struct module *me)
506{
507	int i;
508	Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
509	Elf32_Sym *sym;
510	Elf32_Word *loc;
511	Elf32_Addr val;
512	Elf32_Sword addend;
513	Elf32_Addr dot;
514	Elf_Addr loc0;
515	unsigned int targetsec = sechdrs[relsec].sh_info;
516	//unsigned long dp = (unsigned long)$global$;
517	register unsigned long dp asm ("r27");
518
519	pr_debug("Applying relocate section %u to %u\n", relsec,
520	       targetsec);
521	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
522		/* This is where to make the change */
523		loc = (void *)sechdrs[targetsec].sh_addr
524		      + rel[i].r_offset;
525		/* This is the start of the target section */
526		loc0 = sechdrs[targetsec].sh_addr;
527		/* This is the symbol it is referring to */
528		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
529			+ ELF32_R_SYM(rel[i].r_info);
530		if (!sym->st_value) {
531			printk(KERN_WARNING "%s: Unknown symbol %s\n",
532			       me->name, strtab + sym->st_name);
533			return -ENOENT;
534		}
535		//dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03;
536		dot =  (Elf32_Addr)loc & ~0x03;
537
538		val = sym->st_value;
539		addend = rel[i].r_addend;
540
541#if 0
542#define r(t) ELF32_R_TYPE(rel[i].r_info)==t ? #t :
543		pr_debug("Symbol %s loc 0x%x val 0x%x addend 0x%x: %s\n",
544			strtab + sym->st_name,
545			(uint32_t)loc, val, addend,
546			r(R_PARISC_PLABEL32)
547			r(R_PARISC_DIR32)
548			r(R_PARISC_DIR21L)
549			r(R_PARISC_DIR14R)
550			r(R_PARISC_SEGREL32)
551			r(R_PARISC_DPREL21L)
552			r(R_PARISC_DPREL14R)
553			r(R_PARISC_PCREL17F)
554			r(R_PARISC_PCREL22F)
555			"UNKNOWN");
556#undef r
557#endif
558
559		switch (ELF32_R_TYPE(rel[i].r_info)) {
560		case R_PARISC_PLABEL32:
561			/* 32-bit function address */
562			/* no function descriptors... */
563			*loc = fsel(val, addend);
564			break;
565		case R_PARISC_DIR32:
566			/* direct 32-bit ref */
567			*loc = fsel(val, addend);
568			break;
569		case R_PARISC_DIR21L:
570			/* left 21 bits of effective address */
571			val = lrsel(val, addend);
572			*loc = mask(*loc, 21) | reassemble_21(val);
573			break;
574		case R_PARISC_DIR14R:
575			/* right 14 bits of effective address */
576			val = rrsel(val, addend);
577			*loc = mask(*loc, 14) | reassemble_14(val);
578			break;
579		case R_PARISC_SEGREL32:
580			/* 32-bit segment relative address */
581			/* See note about special handling of SEGREL32 at
582			 * the beginning of this file.
583			 */
584			*loc = fsel(val, addend);
585			break;
586		case R_PARISC_SECREL32:
587			/* 32-bit section relative address. */
588			*loc = fsel(val, addend);
589			break;
590		case R_PARISC_DPREL21L:
591			/* left 21 bit of relative address */
592			val = lrsel(val - dp, addend);
593			*loc = mask(*loc, 21) | reassemble_21(val);
594			break;
595		case R_PARISC_DPREL14R:
596			/* right 14 bit of relative address */
597			val = rrsel(val - dp, addend);
598			*loc = mask(*loc, 14) | reassemble_14(val);
599			break;
600		case R_PARISC_PCREL17F:
601			/* 17-bit PC relative address */
602			/* calculate direct call offset */
603			val += addend;
604			val = (val - dot - 8)/4;
605			if (!RELOC_REACHABLE(val, 17)) {
606				/* direct distance too far, create
607				 * stub entry instead */
608				val = get_stub(me, sym->st_value, addend,
609					ELF_STUB_DIRECT, loc0, targetsec);
610				val = (val - dot - 8)/4;
611				CHECK_RELOC(val, 17);
612			}
613			*loc = (*loc & ~0x1f1ffd) | reassemble_17(val);
614			break;
615		case R_PARISC_PCREL22F:
616			/* 22-bit PC relative address; only defined for pa20 */
617			/* calculate direct call offset */
618			val += addend;
619			val = (val - dot - 8)/4;
620			if (!RELOC_REACHABLE(val, 22)) {
621				/* direct distance too far, create
622				 * stub entry instead */
623				val = get_stub(me, sym->st_value, addend,
624					ELF_STUB_DIRECT, loc0, targetsec);
625				val = (val - dot - 8)/4;
626				CHECK_RELOC(val, 22);
627			}
628			*loc = (*loc & ~0x3ff1ffd) | reassemble_22(val);
629			break;
630		case R_PARISC_PCREL32:
631			/* 32-bit PC relative address */
632			*loc = val - dot - 8 + addend;
633			break;
634
635		default:
636			printk(KERN_ERR "module %s: Unknown relocation: %u\n",
637			       me->name, ELF32_R_TYPE(rel[i].r_info));
638			return -ENOEXEC;
639		}
640	}
641
642	return 0;
643}
644
645#else
646int apply_relocate_add(Elf_Shdr *sechdrs,
647		       const char *strtab,
648		       unsigned int symindex,
649		       unsigned int relsec,
650		       struct module *me)
651{
652	int i;
653	Elf64_Rela *rel = (void *)sechdrs[relsec].sh_addr;
654	Elf64_Sym *sym;
655	Elf64_Word *loc;
656	Elf64_Xword *loc64;
657	Elf64_Addr val;
658	Elf64_Sxword addend;
659	Elf64_Addr dot;
660	Elf_Addr loc0;
661	unsigned int targetsec = sechdrs[relsec].sh_info;
662
663	pr_debug("Applying relocate section %u to %u\n", relsec,
664	       targetsec);
665	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
666		/* This is where to make the change */
667		loc = (void *)sechdrs[targetsec].sh_addr
668		      + rel[i].r_offset;
669		/* This is the start of the target section */
670		loc0 = sechdrs[targetsec].sh_addr;
671		/* This is the symbol it is referring to */
672		sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
673			+ ELF64_R_SYM(rel[i].r_info);
674		if (!sym->st_value) {
675			printk(KERN_WARNING "%s: Unknown symbol %s\n",
676			       me->name, strtab + sym->st_name);
677			return -ENOENT;
678		}
679		//dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03;
680		dot = (Elf64_Addr)loc & ~0x03;
681		loc64 = (Elf64_Xword *)loc;
682
683		val = sym->st_value;
684		addend = rel[i].r_addend;
685
686#if 0
687#define r(t) ELF64_R_TYPE(rel[i].r_info)==t ? #t :
688		printk("Symbol %s loc %p val 0x%Lx addend 0x%Lx: %s\n",
689			strtab + sym->st_name,
690			loc, val, addend,
691			r(R_PARISC_LTOFF14R)
692			r(R_PARISC_LTOFF21L)
693			r(R_PARISC_PCREL22F)
694			r(R_PARISC_DIR64)
695			r(R_PARISC_SEGREL32)
696			r(R_PARISC_FPTR64)
697			"UNKNOWN");
698#undef r
699#endif
700
701		switch (ELF64_R_TYPE(rel[i].r_info)) {
702		case R_PARISC_LTOFF21L:
703			/* LT-relative; left 21 bits */
704			val = get_got(me, val, addend);
705			pr_debug("LTOFF21L Symbol %s loc %p val %llx\n",
706			       strtab + sym->st_name,
707			       loc, val);
708			val = lrsel(val, 0);
709			*loc = mask(*loc, 21) | reassemble_21(val);
710			break;
711		case R_PARISC_LTOFF14R:
712			/* L(ltoff(val+addend)) */
713			/* LT-relative; right 14 bits */
714			val = get_got(me, val, addend);
715			val = rrsel(val, 0);
716			pr_debug("LTOFF14R Symbol %s loc %p val %llx\n",
717			       strtab + sym->st_name,
718			       loc, val);
719			*loc = mask(*loc, 14) | reassemble_14(val);
720			break;
721		case R_PARISC_PCREL22F:
722			/* PC-relative; 22 bits */
723			pr_debug("PCREL22F Symbol %s loc %p val %llx\n",
724			       strtab + sym->st_name,
725			       loc, val);
726			val += addend;
727			/* can we reach it locally? */
728			if (within_module(val, me)) {
729				/* this is the case where the symbol is local
730				 * to the module, but in a different section,
731				 * so stub the jump in case it's more than 22
732				 * bits away */
733				val = (val - dot - 8)/4;
734				if (!RELOC_REACHABLE(val, 22)) {
735					/* direct distance too far, create
736					 * stub entry instead */
737					val = get_stub(me, sym->st_value,
738						addend, ELF_STUB_DIRECT,
739						loc0, targetsec);
740				} else {
741					/* Ok, we can reach it directly. */
742					val = sym->st_value;
743					val += addend;
744				}
745			} else {
746				val = sym->st_value;
747				if (strncmp(strtab + sym->st_name, "$$", 2)
748				    == 0)
749					val = get_stub(me, val, addend, ELF_STUB_MILLI,
750						       loc0, targetsec);
751				else
752					val = get_stub(me, val, addend, ELF_STUB_GOT,
753						       loc0, targetsec);
754			}
755			pr_debug("STUB FOR %s loc %px, val %llx+%llx at %llx\n",
756			       strtab + sym->st_name, loc, sym->st_value,
757			       addend, val);
758			val = (val - dot - 8)/4;
759			CHECK_RELOC(val, 22);
760			*loc = (*loc & ~0x3ff1ffd) | reassemble_22(val);
761			break;
762		case R_PARISC_PCREL32:
763			/* 32-bit PC relative address */
764			*loc = val - dot - 8 + addend;
765			break;
766		case R_PARISC_PCREL64:
767			/* 64-bit PC relative address */
768			*loc64 = val - dot - 8 + addend;
769			break;
770		case R_PARISC_DIR64:
771			/* 64-bit effective address */
772			*loc64 = val + addend;
773			break;
774		case R_PARISC_SEGREL32:
775			/* 32-bit segment relative address */
776			/* See note about special handling of SEGREL32 at
777			 * the beginning of this file.
778			 */
779			*loc = fsel(val, addend);
780			break;
781		case R_PARISC_SECREL32:
782			/* 32-bit section relative address. */
783			*loc = fsel(val, addend);
784			break;
785		case R_PARISC_FPTR64:
786			/* 64-bit function address */
787			if (within_module(val + addend, me)) {
788				*loc64 = get_fdesc(me, val+addend);
789				pr_debug("FDESC for %s at %llx points to %llx\n",
790				       strtab + sym->st_name, *loc64,
791				       ((Elf_Fdesc *)*loc64)->addr);
792			} else {
793				/* if the symbol is not local to this
794				 * module then val+addend is a pointer
795				 * to the function descriptor */
796				pr_debug("Non local FPTR64 Symbol %s loc %p val %llx\n",
797				       strtab + sym->st_name,
798				       loc, val);
799				*loc64 = val + addend;
800			}
801			break;
802
803		default:
804			printk(KERN_ERR "module %s: Unknown relocation: %Lu\n",
805			       me->name, ELF64_R_TYPE(rel[i].r_info));
806			return -ENOEXEC;
807		}
808	}
809	return 0;
810}
811#endif
812
813static void
814register_unwind_table(struct module *me,
815		      const Elf_Shdr *sechdrs)
816{
817	unsigned char *table, *end;
818	unsigned long gp;
819
820	if (!me->arch.unwind_section)
821		return;
822
823	table = (unsigned char *)sechdrs[me->arch.unwind_section].sh_addr;
824	end = table + sechdrs[me->arch.unwind_section].sh_size;
825	gp = (Elf_Addr)me->mem[MOD_TEXT].base + me->arch.got_offset;
826
827	pr_debug("register_unwind_table(), sect = %d at 0x%p - 0x%p (gp=0x%lx)\n",
828	       me->arch.unwind_section, table, end, gp);
829	me->arch.unwind = unwind_table_add(me->name, 0, gp, table, end);
830}
831
832static void
833deregister_unwind_table(struct module *me)
834{
835	if (me->arch.unwind)
836		unwind_table_remove(me->arch.unwind);
837}
838
839int module_finalize(const Elf_Ehdr *hdr,
840		    const Elf_Shdr *sechdrs,
841		    struct module *me)
842{
843	int i;
844	unsigned long nsyms;
845	const char *strtab = NULL;
846	const Elf_Shdr *s;
847	char *secstrings;
848	int symindex __maybe_unused = -1;
849	Elf_Sym *newptr, *oldptr;
850	Elf_Shdr *symhdr = NULL;
851#ifdef DEBUG
852	Elf_Fdesc *entry;
853	u32 *addr;
854
855	entry = (Elf_Fdesc *)me->init;
856	printk("FINALIZE, ->init FPTR is %p, GP %lx ADDR %lx\n", entry,
857	       entry->gp, entry->addr);
858	addr = (u32 *)entry->addr;
859	printk("INSNS: %x %x %x %x\n",
860	       addr[0], addr[1], addr[2], addr[3]);
861	printk("got entries used %ld, gots max %ld\n"
862	       "fdescs used %ld, fdescs max %ld\n",
863	       me->arch.got_count, me->arch.got_max,
864	       me->arch.fdesc_count, me->arch.fdesc_max);
865#endif
866
867	register_unwind_table(me, sechdrs);
868
869	/* haven't filled in me->symtab yet, so have to find it
870	 * ourselves */
871	for (i = 1; i < hdr->e_shnum; i++) {
872		if(sechdrs[i].sh_type == SHT_SYMTAB
873		   && (sechdrs[i].sh_flags & SHF_ALLOC)) {
874			int strindex = sechdrs[i].sh_link;
875			symindex = i;
876			/* FIXME: AWFUL HACK
877			 * The cast is to drop the const from
878			 * the sechdrs pointer */
879			symhdr = (Elf_Shdr *)&sechdrs[i];
880			strtab = (char *)sechdrs[strindex].sh_addr;
881			break;
882		}
883	}
884
885	pr_debug("module %s: strtab %p, symhdr %p\n",
886	       me->name, strtab, symhdr);
887
888	if(me->arch.got_count > MAX_GOTS) {
889		printk(KERN_ERR "%s: Global Offset Table overflow (used %ld, allowed %d)\n",
890				me->name, me->arch.got_count, MAX_GOTS);
891		return -EINVAL;
892	}
893
894	kfree(me->arch.section);
895	me->arch.section = NULL;
896
897	/* no symbol table */
898	if(symhdr == NULL)
899		return 0;
900
901	oldptr = (void *)symhdr->sh_addr;
902	newptr = oldptr + 1;	/* we start counting at 1 */
903	nsyms = symhdr->sh_size / sizeof(Elf_Sym);
904	pr_debug("OLD num_symtab %lu\n", nsyms);
905
906	for (i = 1; i < nsyms; i++) {
907		oldptr++;	/* note, count starts at 1 so preincrement */
908		if(strncmp(strtab + oldptr->st_name,
909			      ".L", 2) == 0)
910			continue;
911
912		if(newptr != oldptr)
913			*newptr++ = *oldptr;
914		else
915			newptr++;
916
917	}
918	nsyms = newptr - (Elf_Sym *)symhdr->sh_addr;
919	pr_debug("NEW num_symtab %lu\n", nsyms);
920	symhdr->sh_size = nsyms * sizeof(Elf_Sym);
921
922	/* find .altinstructions section */
923	secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
924	for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
925		void *aseg = (void *) s->sh_addr;
926		char *secname = secstrings + s->sh_name;
927
928		if (!strcmp(".altinstructions", secname))
929			/* patch .altinstructions */
930			apply_alternatives(aseg, aseg + s->sh_size, me->name);
931
932#ifdef CONFIG_DYNAMIC_FTRACE
933		/* For 32 bit kernels we're compiling modules with
934		 * -ffunction-sections so we must relocate the addresses in the
935		 *  ftrace callsite section.
936		 */
937		if (symindex != -1 && !strcmp(secname, FTRACE_CALLSITE_SECTION)) {
938			int err;
939			if (s->sh_type == SHT_REL)
940				err = apply_relocate((Elf_Shdr *)sechdrs,
941							strtab, symindex,
942							s - sechdrs, me);
943			else if (s->sh_type == SHT_RELA)
944				err = apply_relocate_add((Elf_Shdr *)sechdrs,
945							strtab, symindex,
946							s - sechdrs, me);
947			if (err)
948				return err;
949		}
950#endif
951	}
952	return 0;
953}
954
955void module_arch_cleanup(struct module *mod)
956{
957	deregister_unwind_table(mod);
958}
959
960#ifdef CONFIG_64BIT
961void *dereference_module_function_descriptor(struct module *mod, void *ptr)
962{
963	unsigned long start_opd = (Elf64_Addr)mod->mem[MOD_TEXT].base +
964				   mod->arch.fdesc_offset;
965	unsigned long end_opd = start_opd +
966				mod->arch.fdesc_count * sizeof(Elf64_Fdesc);
967
968	if (ptr < (void *)start_opd || ptr >= (void *)end_opd)
969		return ptr;
970
971	return dereference_function_descriptor(ptr);
972}
973#endif
974