xref: /openbmc/linux/arch/parisc/kernel/module.c (revision 7dd65feb)
1 /*    Kernel dynamically loadable module help for PARISC.
2  *
3  *    The best reference for this stuff is probably the Processor-
4  *    Specific ELF Supplement for PA-RISC:
5  *        http://ftp.parisc-linux.org/docs/arch/elf-pa-hp.pdf
6  *
7  *    Linux/PA-RISC Project (http://www.parisc-linux.org/)
8  *    Copyright (C) 2003 Randolph Chung <tausq at debian . org>
9  *    Copyright (C) 2008 Helge Deller <deller@gmx.de>
10  *
11  *
12  *    This program is free software; you can redistribute it and/or modify
13  *    it under the terms of the GNU General Public License as published by
14  *    the Free Software Foundation; either version 2 of the License, or
15  *    (at your option) any later version.
16  *
17  *    This program is distributed in the hope that it will be useful,
18  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
19  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  *    GNU General Public License for more details.
21  *
22  *    You should have received a copy of the GNU General Public License
23  *    along with this program; if not, write to the Free Software
24  *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
25  *
26  *
27  *    Notes:
28  *    - PLT stub handling
29  *      On 32bit (and sometimes 64bit) and with big kernel modules like xfs or
30  *      ipv6 the relocation types R_PARISC_PCREL17F and R_PARISC_PCREL22F may
31  *      fail to reach their PLT stub if we only create one big stub array for
32  *      all sections at the beginning of the core or init section.
33  *      Instead we now insert individual PLT stub entries directly in front of
34  *      of the code sections where the stubs are actually called.
35  *      This reduces the distance between the PCREL location and the stub entry
36  *      so that the relocations can be fulfilled.
37  *      While calculating the final layout of the kernel module in memory, the
38  *      kernel module loader calls arch_mod_section_prepend() to request the
39  *      to be reserved amount of memory in front of each individual section.
40  *
41  *    - SEGREL32 handling
42  *      We are not doing SEGREL32 handling correctly. According to the ABI, we
43  *      should do a value offset, like this:
44  *			if (in_init(me, (void *)val))
45  *				val -= (uint32_t)me->module_init;
46  *			else
47  *				val -= (uint32_t)me->module_core;
48  *	However, SEGREL32 is used only for PARISC unwind entries, and we want
49  *	those entries to have an absolute address, and not just an offset.
50  *
51  *	The unwind table mechanism has the ability to specify an offset for
52  *	the unwind table; however, because we split off the init functions into
53  *	a different piece of memory, it is not possible to do this using a
54  *	single offset. Instead, we use the above hack for now.
55  */
56 
57 #include <linux/moduleloader.h>
58 #include <linux/elf.h>
59 #include <linux/vmalloc.h>
60 #include <linux/fs.h>
61 #include <linux/string.h>
62 #include <linux/kernel.h>
63 #include <linux/bug.h>
64 
65 #include <asm/unwind.h>
66 
67 #if 0
68 #define DEBUGP printk
69 #else
70 #define DEBUGP(fmt...)
71 #endif
72 
73 #define RELOC_REACHABLE(val, bits) \
74 	(( ( !((val) & (1<<((bits)-1))) && ((val)>>(bits)) != 0 )  ||	\
75 	     ( ((val) & (1<<((bits)-1))) && ((val)>>(bits)) != (((__typeof__(val))(~0))>>((bits)+2)))) ? \
76 	0 : 1)
77 
78 #define CHECK_RELOC(val, bits) \
79 	if (!RELOC_REACHABLE(val, bits)) { \
80 		printk(KERN_ERR "module %s relocation of symbol %s is out of range (0x%lx in %d bits)\n", \
81 		me->name, strtab + sym->st_name, (unsigned long)val, bits); \
82 		return -ENOEXEC;			\
83 	}
84 
85 /* Maximum number of GOT entries. We use a long displacement ldd from
86  * the bottom of the table, which has a maximum signed displacement of
87  * 0x3fff; however, since we're only going forward, this becomes
88  * 0x1fff, and thus, since each GOT entry is 8 bytes long we can have
89  * at most 1023 entries.
90  * To overcome this 14bit displacement with some kernel modules, we'll
91  * use instead the unusal 16bit displacement method (see reassemble_16a)
92  * which gives us a maximum positive displacement of 0x7fff, and as such
93  * allows us to allocate up to 4095 GOT entries. */
94 #define MAX_GOTS	4095
95 
96 /* three functions to determine where in the module core
97  * or init pieces the location is */
98 static inline int in_init(struct module *me, void *loc)
99 {
100 	return (loc >= me->module_init &&
101 		loc <= (me->module_init + me->init_size));
102 }
103 
104 static inline int in_core(struct module *me, void *loc)
105 {
106 	return (loc >= me->module_core &&
107 		loc <= (me->module_core + me->core_size));
108 }
109 
110 static inline int in_local(struct module *me, void *loc)
111 {
112 	return in_init(me, loc) || in_core(me, loc);
113 }
114 
115 #ifndef CONFIG_64BIT
116 struct got_entry {
117 	Elf32_Addr addr;
118 };
119 
120 struct stub_entry {
121 	Elf32_Word insns[2]; /* each stub entry has two insns */
122 };
123 #else
124 struct got_entry {
125 	Elf64_Addr addr;
126 };
127 
128 struct stub_entry {
129 	Elf64_Word insns[4]; /* each stub entry has four insns */
130 };
131 #endif
132 
133 /* Field selection types defined by hppa */
134 #define rnd(x)			(((x)+0x1000)&~0x1fff)
135 /* fsel: full 32 bits */
136 #define fsel(v,a)		((v)+(a))
137 /* lsel: select left 21 bits */
138 #define lsel(v,a)		(((v)+(a))>>11)
139 /* rsel: select right 11 bits */
140 #define rsel(v,a)		(((v)+(a))&0x7ff)
141 /* lrsel with rounding of addend to nearest 8k */
142 #define lrsel(v,a)		(((v)+rnd(a))>>11)
143 /* rrsel with rounding of addend to nearest 8k */
144 #define rrsel(v,a)		((((v)+rnd(a))&0x7ff)+((a)-rnd(a)))
145 
146 #define mask(x,sz)		((x) & ~((1<<(sz))-1))
147 
148 
149 /* The reassemble_* functions prepare an immediate value for
150    insertion into an opcode. pa-risc uses all sorts of weird bitfields
151    in the instruction to hold the value.  */
152 static inline int sign_unext(int x, int len)
153 {
154 	int len_ones;
155 
156 	len_ones = (1 << len) - 1;
157 	return x & len_ones;
158 }
159 
160 static inline int low_sign_unext(int x, int len)
161 {
162 	int sign, temp;
163 
164 	sign = (x >> (len-1)) & 1;
165 	temp = sign_unext(x, len-1);
166 	return (temp << 1) | sign;
167 }
168 
169 static inline int reassemble_14(int as14)
170 {
171 	return (((as14 & 0x1fff) << 1) |
172 		((as14 & 0x2000) >> 13));
173 }
174 
175 static inline int reassemble_16a(int as16)
176 {
177 	int s, t;
178 
179 	/* Unusual 16-bit encoding, for wide mode only.  */
180 	t = (as16 << 1) & 0xffff;
181 	s = (as16 & 0x8000);
182 	return (t ^ s ^ (s >> 1)) | (s >> 15);
183 }
184 
185 
186 static inline int reassemble_17(int as17)
187 {
188 	return (((as17 & 0x10000) >> 16) |
189 		((as17 & 0x0f800) << 5) |
190 		((as17 & 0x00400) >> 8) |
191 		((as17 & 0x003ff) << 3));
192 }
193 
194 static inline int reassemble_21(int as21)
195 {
196 	return (((as21 & 0x100000) >> 20) |
197 		((as21 & 0x0ffe00) >> 8) |
198 		((as21 & 0x000180) << 7) |
199 		((as21 & 0x00007c) << 14) |
200 		((as21 & 0x000003) << 12));
201 }
202 
203 static inline int reassemble_22(int as22)
204 {
205 	return (((as22 & 0x200000) >> 21) |
206 		((as22 & 0x1f0000) << 5) |
207 		((as22 & 0x00f800) << 5) |
208 		((as22 & 0x000400) >> 8) |
209 		((as22 & 0x0003ff) << 3));
210 }
211 
212 void *module_alloc(unsigned long size)
213 {
214 	if (size == 0)
215 		return NULL;
216 	return vmalloc(size);
217 }
218 
219 #ifndef CONFIG_64BIT
220 static inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n)
221 {
222 	return 0;
223 }
224 
225 static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n)
226 {
227 	return 0;
228 }
229 
230 static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n)
231 {
232 	unsigned long cnt = 0;
233 
234 	for (; n > 0; n--, rela++)
235 	{
236 		switch (ELF32_R_TYPE(rela->r_info)) {
237 			case R_PARISC_PCREL17F:
238 			case R_PARISC_PCREL22F:
239 				cnt++;
240 		}
241 	}
242 
243 	return cnt;
244 }
245 #else
246 static inline unsigned long count_gots(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_LTOFF21L:
254 			case R_PARISC_LTOFF14R:
255 			case R_PARISC_PCREL22F:
256 				cnt++;
257 		}
258 	}
259 
260 	return cnt;
261 }
262 
263 static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n)
264 {
265 	unsigned long cnt = 0;
266 
267 	for (; n > 0; n--, rela++)
268 	{
269 		switch (ELF64_R_TYPE(rela->r_info)) {
270 			case R_PARISC_FPTR64:
271 				cnt++;
272 		}
273 	}
274 
275 	return cnt;
276 }
277 
278 static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n)
279 {
280 	unsigned long cnt = 0;
281 
282 	for (; n > 0; n--, rela++)
283 	{
284 		switch (ELF64_R_TYPE(rela->r_info)) {
285 			case R_PARISC_PCREL22F:
286 				cnt++;
287 		}
288 	}
289 
290 	return cnt;
291 }
292 #endif
293 
294 
295 /* Free memory returned from module_alloc */
296 void module_free(struct module *mod, void *module_region)
297 {
298 	kfree(mod->arch.section);
299 	mod->arch.section = NULL;
300 
301 	vfree(module_region);
302 }
303 
304 /* Additional bytes needed in front of individual sections */
305 unsigned int arch_mod_section_prepend(struct module *mod,
306 				      unsigned int section)
307 {
308 	/* size needed for all stubs of this section (including
309 	 * one additional for correct alignment of the stubs) */
310 	return (mod->arch.section[section].stub_entries + 1)
311 		* sizeof(struct stub_entry);
312 }
313 
314 #define CONST
315 int module_frob_arch_sections(CONST Elf_Ehdr *hdr,
316 			      CONST Elf_Shdr *sechdrs,
317 			      CONST char *secstrings,
318 			      struct module *me)
319 {
320 	unsigned long gots = 0, fdescs = 0, len;
321 	unsigned int i;
322 
323 	len = hdr->e_shnum * sizeof(me->arch.section[0]);
324 	me->arch.section = kzalloc(len, GFP_KERNEL);
325 	if (!me->arch.section)
326 		return -ENOMEM;
327 
328 	for (i = 1; i < hdr->e_shnum; i++) {
329 		const Elf_Rela *rels = (void *)sechdrs[i].sh_addr;
330 		unsigned long nrels = sechdrs[i].sh_size / sizeof(*rels);
331 		unsigned int count, s;
332 
333 		if (strncmp(secstrings + sechdrs[i].sh_name,
334 			    ".PARISC.unwind", 14) == 0)
335 			me->arch.unwind_section = i;
336 
337 		if (sechdrs[i].sh_type != SHT_RELA)
338 			continue;
339 
340 		/* some of these are not relevant for 32-bit/64-bit
341 		 * we leave them here to make the code common. the
342 		 * compiler will do its thing and optimize out the
343 		 * stuff we don't need
344 		 */
345 		gots += count_gots(rels, nrels);
346 		fdescs += count_fdescs(rels, nrels);
347 
348 		/* XXX: By sorting the relocs and finding duplicate entries
349 		 *  we could reduce the number of necessary stubs and save
350 		 *  some memory. */
351 		count = count_stubs(rels, nrels);
352 		if (!count)
353 			continue;
354 
355 		/* so we need relocation stubs. reserve necessary memory. */
356 		/* sh_info gives the section for which we need to add stubs. */
357 		s = sechdrs[i].sh_info;
358 
359 		/* each code section should only have one relocation section */
360 		WARN_ON(me->arch.section[s].stub_entries);
361 
362 		/* store number of stubs we need for this section */
363 		me->arch.section[s].stub_entries += count;
364 	}
365 
366 	/* align things a bit */
367 	me->core_size = ALIGN(me->core_size, 16);
368 	me->arch.got_offset = me->core_size;
369 	me->core_size += gots * sizeof(struct got_entry);
370 
371 	me->core_size = ALIGN(me->core_size, 16);
372 	me->arch.fdesc_offset = me->core_size;
373 	me->core_size += fdescs * sizeof(Elf_Fdesc);
374 
375 	me->arch.got_max = gots;
376 	me->arch.fdesc_max = fdescs;
377 
378 	return 0;
379 }
380 
381 #ifdef CONFIG_64BIT
382 static Elf64_Word get_got(struct module *me, unsigned long value, long addend)
383 {
384 	unsigned int i;
385 	struct got_entry *got;
386 
387 	value += addend;
388 
389 	BUG_ON(value == 0);
390 
391 	got = me->module_core + me->arch.got_offset;
392 	for (i = 0; got[i].addr; i++)
393 		if (got[i].addr == value)
394 			goto out;
395 
396 	BUG_ON(++me->arch.got_count > me->arch.got_max);
397 
398 	got[i].addr = value;
399  out:
400 	DEBUGP("GOT ENTRY %d[%x] val %lx\n", i, i*sizeof(struct got_entry),
401 	       value);
402 	return i * sizeof(struct got_entry);
403 }
404 #endif /* CONFIG_64BIT */
405 
406 #ifdef CONFIG_64BIT
407 static Elf_Addr get_fdesc(struct module *me, unsigned long value)
408 {
409 	Elf_Fdesc *fdesc = me->module_core + me->arch.fdesc_offset;
410 
411 	if (!value) {
412 		printk(KERN_ERR "%s: zero OPD requested!\n", me->name);
413 		return 0;
414 	}
415 
416 	/* Look for existing fdesc entry. */
417 	while (fdesc->addr) {
418 		if (fdesc->addr == value)
419 			return (Elf_Addr)fdesc;
420 		fdesc++;
421 	}
422 
423 	BUG_ON(++me->arch.fdesc_count > me->arch.fdesc_max);
424 
425 	/* Create new one */
426 	fdesc->addr = value;
427 	fdesc->gp = (Elf_Addr)me->module_core + me->arch.got_offset;
428 	return (Elf_Addr)fdesc;
429 }
430 #endif /* CONFIG_64BIT */
431 
432 enum elf_stub_type {
433 	ELF_STUB_GOT,
434 	ELF_STUB_MILLI,
435 	ELF_STUB_DIRECT,
436 };
437 
438 static Elf_Addr get_stub(struct module *me, unsigned long value, long addend,
439 	enum elf_stub_type stub_type, Elf_Addr loc0, unsigned int targetsec)
440 {
441 	struct stub_entry *stub;
442 	int __maybe_unused d;
443 
444 	/* initialize stub_offset to point in front of the section */
445 	if (!me->arch.section[targetsec].stub_offset) {
446 		loc0 -= (me->arch.section[targetsec].stub_entries + 1) *
447 				sizeof(struct stub_entry);
448 		/* get correct alignment for the stubs */
449 		loc0 = ALIGN(loc0, sizeof(struct stub_entry));
450 		me->arch.section[targetsec].stub_offset = loc0;
451 	}
452 
453 	/* get address of stub entry */
454 	stub = (void *) me->arch.section[targetsec].stub_offset;
455 	me->arch.section[targetsec].stub_offset += sizeof(struct stub_entry);
456 
457 	/* do not write outside available stub area */
458 	BUG_ON(0 == me->arch.section[targetsec].stub_entries--);
459 
460 
461 #ifndef CONFIG_64BIT
462 /* for 32-bit the stub looks like this:
463  * 	ldil L'XXX,%r1
464  * 	be,n R'XXX(%sr4,%r1)
465  */
466 	//value = *(unsigned long *)((value + addend) & ~3); /* why? */
467 
468 	stub->insns[0] = 0x20200000;	/* ldil L'XXX,%r1	*/
469 	stub->insns[1] = 0xe0202002;	/* be,n R'XXX(%sr4,%r1)	*/
470 
471 	stub->insns[0] |= reassemble_21(lrsel(value, addend));
472 	stub->insns[1] |= reassemble_17(rrsel(value, addend) / 4);
473 
474 #else
475 /* for 64-bit we have three kinds of stubs:
476  * for normal function calls:
477  * 	ldd 0(%dp),%dp
478  * 	ldd 10(%dp), %r1
479  * 	bve (%r1)
480  * 	ldd 18(%dp), %dp
481  *
482  * for millicode:
483  * 	ldil 0, %r1
484  * 	ldo 0(%r1), %r1
485  * 	ldd 10(%r1), %r1
486  * 	bve,n (%r1)
487  *
488  * for direct branches (jumps between different section of the
489  * same module):
490  *	ldil 0, %r1
491  *	ldo 0(%r1), %r1
492  *	bve,n (%r1)
493  */
494 	switch (stub_type) {
495 	case ELF_STUB_GOT:
496 		d = get_got(me, value, addend);
497 		if (d <= 15) {
498 			/* Format 5 */
499 			stub->insns[0] = 0x0f6010db; /* ldd 0(%dp),%dp	*/
500 			stub->insns[0] |= low_sign_unext(d, 5) << 16;
501 		} else {
502 			/* Format 3 */
503 			stub->insns[0] = 0x537b0000; /* ldd 0(%dp),%dp	*/
504 			stub->insns[0] |= reassemble_16a(d);
505 		}
506 		stub->insns[1] = 0x53610020;	/* ldd 10(%dp),%r1	*/
507 		stub->insns[2] = 0xe820d000;	/* bve (%r1)		*/
508 		stub->insns[3] = 0x537b0030;	/* ldd 18(%dp),%dp	*/
509 		break;
510 	case ELF_STUB_MILLI:
511 		stub->insns[0] = 0x20200000;	/* ldil 0,%r1		*/
512 		stub->insns[1] = 0x34210000;	/* ldo 0(%r1), %r1	*/
513 		stub->insns[2] = 0x50210020;	/* ldd 10(%r1),%r1	*/
514 		stub->insns[3] = 0xe820d002;	/* bve,n (%r1)		*/
515 
516 		stub->insns[0] |= reassemble_21(lrsel(value, addend));
517 		stub->insns[1] |= reassemble_14(rrsel(value, addend));
518 		break;
519 	case ELF_STUB_DIRECT:
520 		stub->insns[0] = 0x20200000;    /* ldil 0,%r1           */
521 		stub->insns[1] = 0x34210000;    /* ldo 0(%r1), %r1      */
522 		stub->insns[2] = 0xe820d002;    /* bve,n (%r1)          */
523 
524 		stub->insns[0] |= reassemble_21(lrsel(value, addend));
525 		stub->insns[1] |= reassemble_14(rrsel(value, addend));
526 		break;
527 	}
528 
529 #endif
530 
531 	return (Elf_Addr)stub;
532 }
533 
534 int apply_relocate(Elf_Shdr *sechdrs,
535 		   const char *strtab,
536 		   unsigned int symindex,
537 		   unsigned int relsec,
538 		   struct module *me)
539 {
540 	/* parisc should not need this ... */
541 	printk(KERN_ERR "module %s: RELOCATION unsupported\n",
542 	       me->name);
543 	return -ENOEXEC;
544 }
545 
546 #ifndef CONFIG_64BIT
547 int apply_relocate_add(Elf_Shdr *sechdrs,
548 		       const char *strtab,
549 		       unsigned int symindex,
550 		       unsigned int relsec,
551 		       struct module *me)
552 {
553 	int i;
554 	Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
555 	Elf32_Sym *sym;
556 	Elf32_Word *loc;
557 	Elf32_Addr val;
558 	Elf32_Sword addend;
559 	Elf32_Addr dot;
560 	Elf_Addr loc0;
561 	unsigned int targetsec = sechdrs[relsec].sh_info;
562 	//unsigned long dp = (unsigned long)$global$;
563 	register unsigned long dp asm ("r27");
564 
565 	DEBUGP("Applying relocate section %u to %u\n", relsec,
566 	       targetsec);
567 	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
568 		/* This is where to make the change */
569 		loc = (void *)sechdrs[targetsec].sh_addr
570 		      + rel[i].r_offset;
571 		/* This is the start of the target section */
572 		loc0 = sechdrs[targetsec].sh_addr;
573 		/* This is the symbol it is referring to */
574 		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
575 			+ ELF32_R_SYM(rel[i].r_info);
576 		if (!sym->st_value) {
577 			printk(KERN_WARNING "%s: Unknown symbol %s\n",
578 			       me->name, strtab + sym->st_name);
579 			return -ENOENT;
580 		}
581 		//dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03;
582 		dot =  (Elf32_Addr)loc & ~0x03;
583 
584 		val = sym->st_value;
585 		addend = rel[i].r_addend;
586 
587 #if 0
588 #define r(t) ELF32_R_TYPE(rel[i].r_info)==t ? #t :
589 		DEBUGP("Symbol %s loc 0x%x val 0x%x addend 0x%x: %s\n",
590 			strtab + sym->st_name,
591 			(uint32_t)loc, val, addend,
592 			r(R_PARISC_PLABEL32)
593 			r(R_PARISC_DIR32)
594 			r(R_PARISC_DIR21L)
595 			r(R_PARISC_DIR14R)
596 			r(R_PARISC_SEGREL32)
597 			r(R_PARISC_DPREL21L)
598 			r(R_PARISC_DPREL14R)
599 			r(R_PARISC_PCREL17F)
600 			r(R_PARISC_PCREL22F)
601 			"UNKNOWN");
602 #undef r
603 #endif
604 
605 		switch (ELF32_R_TYPE(rel[i].r_info)) {
606 		case R_PARISC_PLABEL32:
607 			/* 32-bit function address */
608 			/* no function descriptors... */
609 			*loc = fsel(val, addend);
610 			break;
611 		case R_PARISC_DIR32:
612 			/* direct 32-bit ref */
613 			*loc = fsel(val, addend);
614 			break;
615 		case R_PARISC_DIR21L:
616 			/* left 21 bits of effective address */
617 			val = lrsel(val, addend);
618 			*loc = mask(*loc, 21) | reassemble_21(val);
619 			break;
620 		case R_PARISC_DIR14R:
621 			/* right 14 bits of effective address */
622 			val = rrsel(val, addend);
623 			*loc = mask(*loc, 14) | reassemble_14(val);
624 			break;
625 		case R_PARISC_SEGREL32:
626 			/* 32-bit segment relative address */
627 			/* See note about special handling of SEGREL32 at
628 			 * the beginning of this file.
629 			 */
630 			*loc = fsel(val, addend);
631 			break;
632 		case R_PARISC_DPREL21L:
633 			/* left 21 bit of relative address */
634 			val = lrsel(val - dp, addend);
635 			*loc = mask(*loc, 21) | reassemble_21(val);
636 			break;
637 		case R_PARISC_DPREL14R:
638 			/* right 14 bit of relative address */
639 			val = rrsel(val - dp, addend);
640 			*loc = mask(*loc, 14) | reassemble_14(val);
641 			break;
642 		case R_PARISC_PCREL17F:
643 			/* 17-bit PC relative address */
644 			/* calculate direct call offset */
645 			val += addend;
646 			val = (val - dot - 8)/4;
647 			if (!RELOC_REACHABLE(val, 17)) {
648 				/* direct distance too far, create
649 				 * stub entry instead */
650 				val = get_stub(me, sym->st_value, addend,
651 					ELF_STUB_DIRECT, loc0, targetsec);
652 				val = (val - dot - 8)/4;
653 				CHECK_RELOC(val, 17);
654 			}
655 			*loc = (*loc & ~0x1f1ffd) | reassemble_17(val);
656 			break;
657 		case R_PARISC_PCREL22F:
658 			/* 22-bit PC relative address; only defined for pa20 */
659 			/* calculate direct call offset */
660 			val += addend;
661 			val = (val - dot - 8)/4;
662 			if (!RELOC_REACHABLE(val, 22)) {
663 				/* direct distance too far, create
664 				 * stub entry instead */
665 				val = get_stub(me, sym->st_value, addend,
666 					ELF_STUB_DIRECT, loc0, targetsec);
667 				val = (val - dot - 8)/4;
668 				CHECK_RELOC(val, 22);
669 			}
670 			*loc = (*loc & ~0x3ff1ffd) | reassemble_22(val);
671 			break;
672 
673 		default:
674 			printk(KERN_ERR "module %s: Unknown relocation: %u\n",
675 			       me->name, ELF32_R_TYPE(rel[i].r_info));
676 			return -ENOEXEC;
677 		}
678 	}
679 
680 	return 0;
681 }
682 
683 #else
684 int apply_relocate_add(Elf_Shdr *sechdrs,
685 		       const char *strtab,
686 		       unsigned int symindex,
687 		       unsigned int relsec,
688 		       struct module *me)
689 {
690 	int i;
691 	Elf64_Rela *rel = (void *)sechdrs[relsec].sh_addr;
692 	Elf64_Sym *sym;
693 	Elf64_Word *loc;
694 	Elf64_Xword *loc64;
695 	Elf64_Addr val;
696 	Elf64_Sxword addend;
697 	Elf64_Addr dot;
698 	Elf_Addr loc0;
699 	unsigned int targetsec = sechdrs[relsec].sh_info;
700 
701 	DEBUGP("Applying relocate section %u to %u\n", relsec,
702 	       targetsec);
703 	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
704 		/* This is where to make the change */
705 		loc = (void *)sechdrs[targetsec].sh_addr
706 		      + rel[i].r_offset;
707 		/* This is the start of the target section */
708 		loc0 = sechdrs[targetsec].sh_addr;
709 		/* This is the symbol it is referring to */
710 		sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
711 			+ ELF64_R_SYM(rel[i].r_info);
712 		if (!sym->st_value) {
713 			printk(KERN_WARNING "%s: Unknown symbol %s\n",
714 			       me->name, strtab + sym->st_name);
715 			return -ENOENT;
716 		}
717 		//dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03;
718 		dot = (Elf64_Addr)loc & ~0x03;
719 		loc64 = (Elf64_Xword *)loc;
720 
721 		val = sym->st_value;
722 		addend = rel[i].r_addend;
723 
724 #if 0
725 #define r(t) ELF64_R_TYPE(rel[i].r_info)==t ? #t :
726 		printk("Symbol %s loc %p val 0x%Lx addend 0x%Lx: %s\n",
727 			strtab + sym->st_name,
728 			loc, val, addend,
729 			r(R_PARISC_LTOFF14R)
730 			r(R_PARISC_LTOFF21L)
731 			r(R_PARISC_PCREL22F)
732 			r(R_PARISC_DIR64)
733 			r(R_PARISC_SEGREL32)
734 			r(R_PARISC_FPTR64)
735 			"UNKNOWN");
736 #undef r
737 #endif
738 
739 		switch (ELF64_R_TYPE(rel[i].r_info)) {
740 		case R_PARISC_LTOFF21L:
741 			/* LT-relative; left 21 bits */
742 			val = get_got(me, val, addend);
743 			DEBUGP("LTOFF21L Symbol %s loc %p val %lx\n",
744 			       strtab + sym->st_name,
745 			       loc, val);
746 			val = lrsel(val, 0);
747 			*loc = mask(*loc, 21) | reassemble_21(val);
748 			break;
749 		case R_PARISC_LTOFF14R:
750 			/* L(ltoff(val+addend)) */
751 			/* LT-relative; right 14 bits */
752 			val = get_got(me, val, addend);
753 			val = rrsel(val, 0);
754 			DEBUGP("LTOFF14R Symbol %s loc %p val %lx\n",
755 			       strtab + sym->st_name,
756 			       loc, val);
757 			*loc = mask(*loc, 14) | reassemble_14(val);
758 			break;
759 		case R_PARISC_PCREL22F:
760 			/* PC-relative; 22 bits */
761 			DEBUGP("PCREL22F Symbol %s loc %p val %lx\n",
762 			       strtab + sym->st_name,
763 			       loc, val);
764 			val += addend;
765 			/* can we reach it locally? */
766 			if (in_local(me, (void *)val)) {
767 				/* this is the case where the symbol is local
768 				 * to the module, but in a different section,
769 				 * so stub the jump in case it's more than 22
770 				 * bits away */
771 				val = (val - dot - 8)/4;
772 				if (!RELOC_REACHABLE(val, 22)) {
773 					/* direct distance too far, create
774 					 * stub entry instead */
775 					val = get_stub(me, sym->st_value,
776 						addend, ELF_STUB_DIRECT,
777 						loc0, targetsec);
778 				} else {
779 					/* Ok, we can reach it directly. */
780 					val = sym->st_value;
781 					val += addend;
782 				}
783 			} else {
784 				val = sym->st_value;
785 				if (strncmp(strtab + sym->st_name, "$$", 2)
786 				    == 0)
787 					val = get_stub(me, val, addend, ELF_STUB_MILLI,
788 						       loc0, targetsec);
789 				else
790 					val = get_stub(me, val, addend, ELF_STUB_GOT,
791 						       loc0, targetsec);
792 			}
793 			DEBUGP("STUB FOR %s loc %lx, val %lx+%lx at %lx\n",
794 			       strtab + sym->st_name, loc, sym->st_value,
795 			       addend, val);
796 			val = (val - dot - 8)/4;
797 			CHECK_RELOC(val, 22);
798 			*loc = (*loc & ~0x3ff1ffd) | reassemble_22(val);
799 			break;
800 		case R_PARISC_DIR64:
801 			/* 64-bit effective address */
802 			*loc64 = val + addend;
803 			break;
804 		case R_PARISC_SEGREL32:
805 			/* 32-bit segment relative address */
806 			/* See note about special handling of SEGREL32 at
807 			 * the beginning of this file.
808 			 */
809 			*loc = fsel(val, addend);
810 			break;
811 		case R_PARISC_FPTR64:
812 			/* 64-bit function address */
813 			if(in_local(me, (void *)(val + addend))) {
814 				*loc64 = get_fdesc(me, val+addend);
815 				DEBUGP("FDESC for %s at %p points to %lx\n",
816 				       strtab + sym->st_name, *loc64,
817 				       ((Elf_Fdesc *)*loc64)->addr);
818 			} else {
819 				/* if the symbol is not local to this
820 				 * module then val+addend is a pointer
821 				 * to the function descriptor */
822 				DEBUGP("Non local FPTR64 Symbol %s loc %p val %lx\n",
823 				       strtab + sym->st_name,
824 				       loc, val);
825 				*loc64 = val + addend;
826 			}
827 			break;
828 
829 		default:
830 			printk(KERN_ERR "module %s: Unknown relocation: %Lu\n",
831 			       me->name, ELF64_R_TYPE(rel[i].r_info));
832 			return -ENOEXEC;
833 		}
834 	}
835 	return 0;
836 }
837 #endif
838 
839 static void
840 register_unwind_table(struct module *me,
841 		      const Elf_Shdr *sechdrs)
842 {
843 	unsigned char *table, *end;
844 	unsigned long gp;
845 
846 	if (!me->arch.unwind_section)
847 		return;
848 
849 	table = (unsigned char *)sechdrs[me->arch.unwind_section].sh_addr;
850 	end = table + sechdrs[me->arch.unwind_section].sh_size;
851 	gp = (Elf_Addr)me->module_core + me->arch.got_offset;
852 
853 	DEBUGP("register_unwind_table(), sect = %d at 0x%p - 0x%p (gp=0x%lx)\n",
854 	       me->arch.unwind_section, table, end, gp);
855 	me->arch.unwind = unwind_table_add(me->name, 0, gp, table, end);
856 }
857 
858 static void
859 deregister_unwind_table(struct module *me)
860 {
861 	if (me->arch.unwind)
862 		unwind_table_remove(me->arch.unwind);
863 }
864 
865 int module_finalize(const Elf_Ehdr *hdr,
866 		    const Elf_Shdr *sechdrs,
867 		    struct module *me)
868 {
869 	int i;
870 	unsigned long nsyms;
871 	const char *strtab = NULL;
872 	Elf_Sym *newptr, *oldptr;
873 	Elf_Shdr *symhdr = NULL;
874 #ifdef DEBUG
875 	Elf_Fdesc *entry;
876 	u32 *addr;
877 
878 	entry = (Elf_Fdesc *)me->init;
879 	printk("FINALIZE, ->init FPTR is %p, GP %lx ADDR %lx\n", entry,
880 	       entry->gp, entry->addr);
881 	addr = (u32 *)entry->addr;
882 	printk("INSNS: %x %x %x %x\n",
883 	       addr[0], addr[1], addr[2], addr[3]);
884 	printk("got entries used %ld, gots max %ld\n"
885 	       "fdescs used %ld, fdescs max %ld\n",
886 	       me->arch.got_count, me->arch.got_max,
887 	       me->arch.fdesc_count, me->arch.fdesc_max);
888 #endif
889 
890 	register_unwind_table(me, sechdrs);
891 
892 	/* haven't filled in me->symtab yet, so have to find it
893 	 * ourselves */
894 	for (i = 1; i < hdr->e_shnum; i++) {
895 		if(sechdrs[i].sh_type == SHT_SYMTAB
896 		   && (sechdrs[i].sh_flags & SHF_ALLOC)) {
897 			int strindex = sechdrs[i].sh_link;
898 			/* FIXME: AWFUL HACK
899 			 * The cast is to drop the const from
900 			 * the sechdrs pointer */
901 			symhdr = (Elf_Shdr *)&sechdrs[i];
902 			strtab = (char *)sechdrs[strindex].sh_addr;
903 			break;
904 		}
905 	}
906 
907 	DEBUGP("module %s: strtab %p, symhdr %p\n",
908 	       me->name, strtab, symhdr);
909 
910 	if(me->arch.got_count > MAX_GOTS) {
911 		printk(KERN_ERR "%s: Global Offset Table overflow (used %ld, allowed %d)\n",
912 				me->name, me->arch.got_count, MAX_GOTS);
913 		return -EINVAL;
914 	}
915 
916 	kfree(me->arch.section);
917 	me->arch.section = NULL;
918 
919 	/* no symbol table */
920 	if(symhdr == NULL)
921 		return 0;
922 
923 	oldptr = (void *)symhdr->sh_addr;
924 	newptr = oldptr + 1;	/* we start counting at 1 */
925 	nsyms = symhdr->sh_size / sizeof(Elf_Sym);
926 	DEBUGP("OLD num_symtab %lu\n", nsyms);
927 
928 	for (i = 1; i < nsyms; i++) {
929 		oldptr++;	/* note, count starts at 1 so preincrement */
930 		if(strncmp(strtab + oldptr->st_name,
931 			      ".L", 2) == 0)
932 			continue;
933 
934 		if(newptr != oldptr)
935 			*newptr++ = *oldptr;
936 		else
937 			newptr++;
938 
939 	}
940 	nsyms = newptr - (Elf_Sym *)symhdr->sh_addr;
941 	DEBUGP("NEW num_symtab %lu\n", nsyms);
942 	symhdr->sh_size = nsyms * sizeof(Elf_Sym);
943 	return module_bug_finalize(hdr, sechdrs, me);
944 }
945 
946 void module_arch_cleanup(struct module *mod)
947 {
948 	deregister_unwind_table(mod);
949 	module_bug_cleanup(mod);
950 }
951