xref: /openbmc/linux/arch/parisc/kernel/module.c (revision 0da85d1e)
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 #include <linux/mm.h>
65 #include <linux/slab.h>
66 
67 #include <asm/pgtable.h>
68 #include <asm/unwind.h>
69 
70 #if 0
71 #define DEBUGP printk
72 #else
73 #define DEBUGP(fmt...)
74 #endif
75 
76 #define RELOC_REACHABLE(val, bits) \
77 	(( ( !((val) & (1<<((bits)-1))) && ((val)>>(bits)) != 0 )  ||	\
78 	     ( ((val) & (1<<((bits)-1))) && ((val)>>(bits)) != (((__typeof__(val))(~0))>>((bits)+2)))) ? \
79 	0 : 1)
80 
81 #define CHECK_RELOC(val, bits) \
82 	if (!RELOC_REACHABLE(val, bits)) { \
83 		printk(KERN_ERR "module %s relocation of symbol %s is out of range (0x%lx in %d bits)\n", \
84 		me->name, strtab + sym->st_name, (unsigned long)val, bits); \
85 		return -ENOEXEC;			\
86 	}
87 
88 /* Maximum number of GOT entries. We use a long displacement ldd from
89  * the bottom of the table, which has a maximum signed displacement of
90  * 0x3fff; however, since we're only going forward, this becomes
91  * 0x1fff, and thus, since each GOT entry is 8 bytes long we can have
92  * at most 1023 entries.
93  * To overcome this 14bit displacement with some kernel modules, we'll
94  * use instead the unusal 16bit displacement method (see reassemble_16a)
95  * which gives us a maximum positive displacement of 0x7fff, and as such
96  * allows us to allocate up to 4095 GOT entries. */
97 #define MAX_GOTS	4095
98 
99 /* three functions to determine where in the module core
100  * or init pieces the location is */
101 static inline int in_init(struct module *me, void *loc)
102 {
103 	return (loc >= me->module_init &&
104 		loc <= (me->module_init + me->init_size));
105 }
106 
107 static inline int in_core(struct module *me, void *loc)
108 {
109 	return (loc >= me->module_core &&
110 		loc <= (me->module_core + me->core_size));
111 }
112 
113 static inline int in_local(struct module *me, void *loc)
114 {
115 	return in_init(me, loc) || in_core(me, loc);
116 }
117 
118 #ifndef CONFIG_64BIT
119 struct got_entry {
120 	Elf32_Addr addr;
121 };
122 
123 struct stub_entry {
124 	Elf32_Word insns[2]; /* each stub entry has two insns */
125 };
126 #else
127 struct got_entry {
128 	Elf64_Addr addr;
129 };
130 
131 struct stub_entry {
132 	Elf64_Word insns[4]; /* each stub entry has four insns */
133 };
134 #endif
135 
136 /* Field selection types defined by hppa */
137 #define rnd(x)			(((x)+0x1000)&~0x1fff)
138 /* fsel: full 32 bits */
139 #define fsel(v,a)		((v)+(a))
140 /* lsel: select left 21 bits */
141 #define lsel(v,a)		(((v)+(a))>>11)
142 /* rsel: select right 11 bits */
143 #define rsel(v,a)		(((v)+(a))&0x7ff)
144 /* lrsel with rounding of addend to nearest 8k */
145 #define lrsel(v,a)		(((v)+rnd(a))>>11)
146 /* rrsel with rounding of addend to nearest 8k */
147 #define rrsel(v,a)		((((v)+rnd(a))&0x7ff)+((a)-rnd(a)))
148 
149 #define mask(x,sz)		((x) & ~((1<<(sz))-1))
150 
151 
152 /* The reassemble_* functions prepare an immediate value for
153    insertion into an opcode. pa-risc uses all sorts of weird bitfields
154    in the instruction to hold the value.  */
155 static inline int sign_unext(int x, int len)
156 {
157 	int len_ones;
158 
159 	len_ones = (1 << len) - 1;
160 	return x & len_ones;
161 }
162 
163 static inline int low_sign_unext(int x, int len)
164 {
165 	int sign, temp;
166 
167 	sign = (x >> (len-1)) & 1;
168 	temp = sign_unext(x, len-1);
169 	return (temp << 1) | sign;
170 }
171 
172 static inline int reassemble_14(int as14)
173 {
174 	return (((as14 & 0x1fff) << 1) |
175 		((as14 & 0x2000) >> 13));
176 }
177 
178 static inline int reassemble_16a(int as16)
179 {
180 	int s, t;
181 
182 	/* Unusual 16-bit encoding, for wide mode only.  */
183 	t = (as16 << 1) & 0xffff;
184 	s = (as16 & 0x8000);
185 	return (t ^ s ^ (s >> 1)) | (s >> 15);
186 }
187 
188 
189 static inline int reassemble_17(int as17)
190 {
191 	return (((as17 & 0x10000) >> 16) |
192 		((as17 & 0x0f800) << 5) |
193 		((as17 & 0x00400) >> 8) |
194 		((as17 & 0x003ff) << 3));
195 }
196 
197 static inline int reassemble_21(int as21)
198 {
199 	return (((as21 & 0x100000) >> 20) |
200 		((as21 & 0x0ffe00) >> 8) |
201 		((as21 & 0x000180) << 7) |
202 		((as21 & 0x00007c) << 14) |
203 		((as21 & 0x000003) << 12));
204 }
205 
206 static inline int reassemble_22(int as22)
207 {
208 	return (((as22 & 0x200000) >> 21) |
209 		((as22 & 0x1f0000) << 5) |
210 		((as22 & 0x00f800) << 5) |
211 		((as22 & 0x000400) >> 8) |
212 		((as22 & 0x0003ff) << 3));
213 }
214 
215 void *module_alloc(unsigned long size)
216 {
217 	/* using RWX means less protection for modules, but it's
218 	 * easier than trying to map the text, data, init_text and
219 	 * init_data correctly */
220 	return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
221 				    GFP_KERNEL | __GFP_HIGHMEM,
222 				    PAGE_KERNEL_RWX, 0, NUMA_NO_NODE,
223 				    __builtin_return_address(0));
224 }
225 
226 #ifndef CONFIG_64BIT
227 static inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n)
228 {
229 	return 0;
230 }
231 
232 static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n)
233 {
234 	return 0;
235 }
236 
237 static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n)
238 {
239 	unsigned long cnt = 0;
240 
241 	for (; n > 0; n--, rela++)
242 	{
243 		switch (ELF32_R_TYPE(rela->r_info)) {
244 			case R_PARISC_PCREL17F:
245 			case R_PARISC_PCREL22F:
246 				cnt++;
247 		}
248 	}
249 
250 	return cnt;
251 }
252 #else
253 static inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n)
254 {
255 	unsigned long cnt = 0;
256 
257 	for (; n > 0; n--, rela++)
258 	{
259 		switch (ELF64_R_TYPE(rela->r_info)) {
260 			case R_PARISC_LTOFF21L:
261 			case R_PARISC_LTOFF14R:
262 			case R_PARISC_PCREL22F:
263 				cnt++;
264 		}
265 	}
266 
267 	return cnt;
268 }
269 
270 static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n)
271 {
272 	unsigned long cnt = 0;
273 
274 	for (; n > 0; n--, rela++)
275 	{
276 		switch (ELF64_R_TYPE(rela->r_info)) {
277 			case R_PARISC_FPTR64:
278 				cnt++;
279 		}
280 	}
281 
282 	return cnt;
283 }
284 
285 static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n)
286 {
287 	unsigned long cnt = 0;
288 
289 	for (; n > 0; n--, rela++)
290 	{
291 		switch (ELF64_R_TYPE(rela->r_info)) {
292 			case R_PARISC_PCREL22F:
293 				cnt++;
294 		}
295 	}
296 
297 	return cnt;
298 }
299 #endif
300 
301 void module_arch_freeing_init(struct module *mod)
302 {
303 	kfree(mod->arch.section);
304 	mod->arch.section = NULL;
305 }
306 
307 /* Additional bytes needed in front of individual sections */
308 unsigned int arch_mod_section_prepend(struct module *mod,
309 				      unsigned int section)
310 {
311 	/* size needed for all stubs of this section (including
312 	 * one additional for correct alignment of the stubs) */
313 	return (mod->arch.section[section].stub_entries + 1)
314 		* sizeof(struct stub_entry);
315 }
316 
317 #define CONST
318 int module_frob_arch_sections(CONST Elf_Ehdr *hdr,
319 			      CONST Elf_Shdr *sechdrs,
320 			      CONST char *secstrings,
321 			      struct module *me)
322 {
323 	unsigned long gots = 0, fdescs = 0, len;
324 	unsigned int i;
325 
326 	len = hdr->e_shnum * sizeof(me->arch.section[0]);
327 	me->arch.section = kzalloc(len, GFP_KERNEL);
328 	if (!me->arch.section)
329 		return -ENOMEM;
330 
331 	for (i = 1; i < hdr->e_shnum; i++) {
332 		const Elf_Rela *rels = (void *)sechdrs[i].sh_addr;
333 		unsigned long nrels = sechdrs[i].sh_size / sizeof(*rels);
334 		unsigned int count, s;
335 
336 		if (strncmp(secstrings + sechdrs[i].sh_name,
337 			    ".PARISC.unwind", 14) == 0)
338 			me->arch.unwind_section = i;
339 
340 		if (sechdrs[i].sh_type != SHT_RELA)
341 			continue;
342 
343 		/* some of these are not relevant for 32-bit/64-bit
344 		 * we leave them here to make the code common. the
345 		 * compiler will do its thing and optimize out the
346 		 * stuff we don't need
347 		 */
348 		gots += count_gots(rels, nrels);
349 		fdescs += count_fdescs(rels, nrels);
350 
351 		/* XXX: By sorting the relocs and finding duplicate entries
352 		 *  we could reduce the number of necessary stubs and save
353 		 *  some memory. */
354 		count = count_stubs(rels, nrels);
355 		if (!count)
356 			continue;
357 
358 		/* so we need relocation stubs. reserve necessary memory. */
359 		/* sh_info gives the section for which we need to add stubs. */
360 		s = sechdrs[i].sh_info;
361 
362 		/* each code section should only have one relocation section */
363 		WARN_ON(me->arch.section[s].stub_entries);
364 
365 		/* store number of stubs we need for this section */
366 		me->arch.section[s].stub_entries += count;
367 	}
368 
369 	/* align things a bit */
370 	me->core_size = ALIGN(me->core_size, 16);
371 	me->arch.got_offset = me->core_size;
372 	me->core_size += gots * sizeof(struct got_entry);
373 
374 	me->core_size = ALIGN(me->core_size, 16);
375 	me->arch.fdesc_offset = me->core_size;
376 	me->core_size += fdescs * sizeof(Elf_Fdesc);
377 
378 	me->arch.got_max = gots;
379 	me->arch.fdesc_max = fdescs;
380 
381 	return 0;
382 }
383 
384 #ifdef CONFIG_64BIT
385 static Elf64_Word get_got(struct module *me, unsigned long value, long addend)
386 {
387 	unsigned int i;
388 	struct got_entry *got;
389 
390 	value += addend;
391 
392 	BUG_ON(value == 0);
393 
394 	got = me->module_core + me->arch.got_offset;
395 	for (i = 0; got[i].addr; i++)
396 		if (got[i].addr == value)
397 			goto out;
398 
399 	BUG_ON(++me->arch.got_count > me->arch.got_max);
400 
401 	got[i].addr = value;
402  out:
403 	DEBUGP("GOT ENTRY %d[%x] val %lx\n", i, i*sizeof(struct got_entry),
404 	       value);
405 	return i * sizeof(struct got_entry);
406 }
407 #endif /* CONFIG_64BIT */
408 
409 #ifdef CONFIG_64BIT
410 static Elf_Addr get_fdesc(struct module *me, unsigned long value)
411 {
412 	Elf_Fdesc *fdesc = me->module_core + me->arch.fdesc_offset;
413 
414 	if (!value) {
415 		printk(KERN_ERR "%s: zero OPD requested!\n", me->name);
416 		return 0;
417 	}
418 
419 	/* Look for existing fdesc entry. */
420 	while (fdesc->addr) {
421 		if (fdesc->addr == value)
422 			return (Elf_Addr)fdesc;
423 		fdesc++;
424 	}
425 
426 	BUG_ON(++me->arch.fdesc_count > me->arch.fdesc_max);
427 
428 	/* Create new one */
429 	fdesc->addr = value;
430 	fdesc->gp = (Elf_Addr)me->module_core + me->arch.got_offset;
431 	return (Elf_Addr)fdesc;
432 }
433 #endif /* CONFIG_64BIT */
434 
435 enum elf_stub_type {
436 	ELF_STUB_GOT,
437 	ELF_STUB_MILLI,
438 	ELF_STUB_DIRECT,
439 };
440 
441 static Elf_Addr get_stub(struct module *me, unsigned long value, long addend,
442 	enum elf_stub_type stub_type, Elf_Addr loc0, unsigned int targetsec)
443 {
444 	struct stub_entry *stub;
445 	int __maybe_unused d;
446 
447 	/* initialize stub_offset to point in front of the section */
448 	if (!me->arch.section[targetsec].stub_offset) {
449 		loc0 -= (me->arch.section[targetsec].stub_entries + 1) *
450 				sizeof(struct stub_entry);
451 		/* get correct alignment for the stubs */
452 		loc0 = ALIGN(loc0, sizeof(struct stub_entry));
453 		me->arch.section[targetsec].stub_offset = loc0;
454 	}
455 
456 	/* get address of stub entry */
457 	stub = (void *) me->arch.section[targetsec].stub_offset;
458 	me->arch.section[targetsec].stub_offset += sizeof(struct stub_entry);
459 
460 	/* do not write outside available stub area */
461 	BUG_ON(0 == me->arch.section[targetsec].stub_entries--);
462 
463 
464 #ifndef CONFIG_64BIT
465 /* for 32-bit the stub looks like this:
466  * 	ldil L'XXX,%r1
467  * 	be,n R'XXX(%sr4,%r1)
468  */
469 	//value = *(unsigned long *)((value + addend) & ~3); /* why? */
470 
471 	stub->insns[0] = 0x20200000;	/* ldil L'XXX,%r1	*/
472 	stub->insns[1] = 0xe0202002;	/* be,n R'XXX(%sr4,%r1)	*/
473 
474 	stub->insns[0] |= reassemble_21(lrsel(value, addend));
475 	stub->insns[1] |= reassemble_17(rrsel(value, addend) / 4);
476 
477 #else
478 /* for 64-bit we have three kinds of stubs:
479  * for normal function calls:
480  * 	ldd 0(%dp),%dp
481  * 	ldd 10(%dp), %r1
482  * 	bve (%r1)
483  * 	ldd 18(%dp), %dp
484  *
485  * for millicode:
486  * 	ldil 0, %r1
487  * 	ldo 0(%r1), %r1
488  * 	ldd 10(%r1), %r1
489  * 	bve,n (%r1)
490  *
491  * for direct branches (jumps between different section of the
492  * same module):
493  *	ldil 0, %r1
494  *	ldo 0(%r1), %r1
495  *	bve,n (%r1)
496  */
497 	switch (stub_type) {
498 	case ELF_STUB_GOT:
499 		d = get_got(me, value, addend);
500 		if (d <= 15) {
501 			/* Format 5 */
502 			stub->insns[0] = 0x0f6010db; /* ldd 0(%dp),%dp	*/
503 			stub->insns[0] |= low_sign_unext(d, 5) << 16;
504 		} else {
505 			/* Format 3 */
506 			stub->insns[0] = 0x537b0000; /* ldd 0(%dp),%dp	*/
507 			stub->insns[0] |= reassemble_16a(d);
508 		}
509 		stub->insns[1] = 0x53610020;	/* ldd 10(%dp),%r1	*/
510 		stub->insns[2] = 0xe820d000;	/* bve (%r1)		*/
511 		stub->insns[3] = 0x537b0030;	/* ldd 18(%dp),%dp	*/
512 		break;
513 	case ELF_STUB_MILLI:
514 		stub->insns[0] = 0x20200000;	/* ldil 0,%r1		*/
515 		stub->insns[1] = 0x34210000;	/* ldo 0(%r1), %r1	*/
516 		stub->insns[2] = 0x50210020;	/* ldd 10(%r1),%r1	*/
517 		stub->insns[3] = 0xe820d002;	/* bve,n (%r1)		*/
518 
519 		stub->insns[0] |= reassemble_21(lrsel(value, addend));
520 		stub->insns[1] |= reassemble_14(rrsel(value, addend));
521 		break;
522 	case ELF_STUB_DIRECT:
523 		stub->insns[0] = 0x20200000;    /* ldil 0,%r1           */
524 		stub->insns[1] = 0x34210000;    /* ldo 0(%r1), %r1      */
525 		stub->insns[2] = 0xe820d002;    /* bve,n (%r1)          */
526 
527 		stub->insns[0] |= reassemble_21(lrsel(value, addend));
528 		stub->insns[1] |= reassemble_14(rrsel(value, addend));
529 		break;
530 	}
531 
532 #endif
533 
534 	return (Elf_Addr)stub;
535 }
536 
537 #ifndef CONFIG_64BIT
538 int apply_relocate_add(Elf_Shdr *sechdrs,
539 		       const char *strtab,
540 		       unsigned int symindex,
541 		       unsigned int relsec,
542 		       struct module *me)
543 {
544 	int i;
545 	Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
546 	Elf32_Sym *sym;
547 	Elf32_Word *loc;
548 	Elf32_Addr val;
549 	Elf32_Sword addend;
550 	Elf32_Addr dot;
551 	Elf_Addr loc0;
552 	unsigned int targetsec = sechdrs[relsec].sh_info;
553 	//unsigned long dp = (unsigned long)$global$;
554 	register unsigned long dp asm ("r27");
555 
556 	DEBUGP("Applying relocate section %u to %u\n", relsec,
557 	       targetsec);
558 	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
559 		/* This is where to make the change */
560 		loc = (void *)sechdrs[targetsec].sh_addr
561 		      + rel[i].r_offset;
562 		/* This is the start of the target section */
563 		loc0 = sechdrs[targetsec].sh_addr;
564 		/* This is the symbol it is referring to */
565 		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
566 			+ ELF32_R_SYM(rel[i].r_info);
567 		if (!sym->st_value) {
568 			printk(KERN_WARNING "%s: Unknown symbol %s\n",
569 			       me->name, strtab + sym->st_name);
570 			return -ENOENT;
571 		}
572 		//dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03;
573 		dot =  (Elf32_Addr)loc & ~0x03;
574 
575 		val = sym->st_value;
576 		addend = rel[i].r_addend;
577 
578 #if 0
579 #define r(t) ELF32_R_TYPE(rel[i].r_info)==t ? #t :
580 		DEBUGP("Symbol %s loc 0x%x val 0x%x addend 0x%x: %s\n",
581 			strtab + sym->st_name,
582 			(uint32_t)loc, val, addend,
583 			r(R_PARISC_PLABEL32)
584 			r(R_PARISC_DIR32)
585 			r(R_PARISC_DIR21L)
586 			r(R_PARISC_DIR14R)
587 			r(R_PARISC_SEGREL32)
588 			r(R_PARISC_DPREL21L)
589 			r(R_PARISC_DPREL14R)
590 			r(R_PARISC_PCREL17F)
591 			r(R_PARISC_PCREL22F)
592 			"UNKNOWN");
593 #undef r
594 #endif
595 
596 		switch (ELF32_R_TYPE(rel[i].r_info)) {
597 		case R_PARISC_PLABEL32:
598 			/* 32-bit function address */
599 			/* no function descriptors... */
600 			*loc = fsel(val, addend);
601 			break;
602 		case R_PARISC_DIR32:
603 			/* direct 32-bit ref */
604 			*loc = fsel(val, addend);
605 			break;
606 		case R_PARISC_DIR21L:
607 			/* left 21 bits of effective address */
608 			val = lrsel(val, addend);
609 			*loc = mask(*loc, 21) | reassemble_21(val);
610 			break;
611 		case R_PARISC_DIR14R:
612 			/* right 14 bits of effective address */
613 			val = rrsel(val, addend);
614 			*loc = mask(*loc, 14) | reassemble_14(val);
615 			break;
616 		case R_PARISC_SEGREL32:
617 			/* 32-bit segment relative address */
618 			/* See note about special handling of SEGREL32 at
619 			 * the beginning of this file.
620 			 */
621 			*loc = fsel(val, addend);
622 			break;
623 		case R_PARISC_DPREL21L:
624 			/* left 21 bit of relative address */
625 			val = lrsel(val - dp, addend);
626 			*loc = mask(*loc, 21) | reassemble_21(val);
627 			break;
628 		case R_PARISC_DPREL14R:
629 			/* right 14 bit of relative address */
630 			val = rrsel(val - dp, addend);
631 			*loc = mask(*loc, 14) | reassemble_14(val);
632 			break;
633 		case R_PARISC_PCREL17F:
634 			/* 17-bit PC relative address */
635 			/* calculate direct call offset */
636 			val += addend;
637 			val = (val - dot - 8)/4;
638 			if (!RELOC_REACHABLE(val, 17)) {
639 				/* direct distance too far, create
640 				 * stub entry instead */
641 				val = get_stub(me, sym->st_value, addend,
642 					ELF_STUB_DIRECT, loc0, targetsec);
643 				val = (val - dot - 8)/4;
644 				CHECK_RELOC(val, 17);
645 			}
646 			*loc = (*loc & ~0x1f1ffd) | reassemble_17(val);
647 			break;
648 		case R_PARISC_PCREL22F:
649 			/* 22-bit PC relative address; only defined for pa20 */
650 			/* calculate direct call offset */
651 			val += addend;
652 			val = (val - dot - 8)/4;
653 			if (!RELOC_REACHABLE(val, 22)) {
654 				/* direct distance too far, create
655 				 * stub entry instead */
656 				val = get_stub(me, sym->st_value, addend,
657 					ELF_STUB_DIRECT, loc0, targetsec);
658 				val = (val - dot - 8)/4;
659 				CHECK_RELOC(val, 22);
660 			}
661 			*loc = (*loc & ~0x3ff1ffd) | reassemble_22(val);
662 			break;
663 
664 		default:
665 			printk(KERN_ERR "module %s: Unknown relocation: %u\n",
666 			       me->name, ELF32_R_TYPE(rel[i].r_info));
667 			return -ENOEXEC;
668 		}
669 	}
670 
671 	return 0;
672 }
673 
674 #else
675 int apply_relocate_add(Elf_Shdr *sechdrs,
676 		       const char *strtab,
677 		       unsigned int symindex,
678 		       unsigned int relsec,
679 		       struct module *me)
680 {
681 	int i;
682 	Elf64_Rela *rel = (void *)sechdrs[relsec].sh_addr;
683 	Elf64_Sym *sym;
684 	Elf64_Word *loc;
685 	Elf64_Xword *loc64;
686 	Elf64_Addr val;
687 	Elf64_Sxword addend;
688 	Elf64_Addr dot;
689 	Elf_Addr loc0;
690 	unsigned int targetsec = sechdrs[relsec].sh_info;
691 
692 	DEBUGP("Applying relocate section %u to %u\n", relsec,
693 	       targetsec);
694 	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
695 		/* This is where to make the change */
696 		loc = (void *)sechdrs[targetsec].sh_addr
697 		      + rel[i].r_offset;
698 		/* This is the start of the target section */
699 		loc0 = sechdrs[targetsec].sh_addr;
700 		/* This is the symbol it is referring to */
701 		sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
702 			+ ELF64_R_SYM(rel[i].r_info);
703 		if (!sym->st_value) {
704 			printk(KERN_WARNING "%s: Unknown symbol %s\n",
705 			       me->name, strtab + sym->st_name);
706 			return -ENOENT;
707 		}
708 		//dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03;
709 		dot = (Elf64_Addr)loc & ~0x03;
710 		loc64 = (Elf64_Xword *)loc;
711 
712 		val = sym->st_value;
713 		addend = rel[i].r_addend;
714 
715 #if 0
716 #define r(t) ELF64_R_TYPE(rel[i].r_info)==t ? #t :
717 		printk("Symbol %s loc %p val 0x%Lx addend 0x%Lx: %s\n",
718 			strtab + sym->st_name,
719 			loc, val, addend,
720 			r(R_PARISC_LTOFF14R)
721 			r(R_PARISC_LTOFF21L)
722 			r(R_PARISC_PCREL22F)
723 			r(R_PARISC_DIR64)
724 			r(R_PARISC_SEGREL32)
725 			r(R_PARISC_FPTR64)
726 			"UNKNOWN");
727 #undef r
728 #endif
729 
730 		switch (ELF64_R_TYPE(rel[i].r_info)) {
731 		case R_PARISC_LTOFF21L:
732 			/* LT-relative; left 21 bits */
733 			val = get_got(me, val, addend);
734 			DEBUGP("LTOFF21L Symbol %s loc %p val %lx\n",
735 			       strtab + sym->st_name,
736 			       loc, val);
737 			val = lrsel(val, 0);
738 			*loc = mask(*loc, 21) | reassemble_21(val);
739 			break;
740 		case R_PARISC_LTOFF14R:
741 			/* L(ltoff(val+addend)) */
742 			/* LT-relative; right 14 bits */
743 			val = get_got(me, val, addend);
744 			val = rrsel(val, 0);
745 			DEBUGP("LTOFF14R Symbol %s loc %p val %lx\n",
746 			       strtab + sym->st_name,
747 			       loc, val);
748 			*loc = mask(*loc, 14) | reassemble_14(val);
749 			break;
750 		case R_PARISC_PCREL22F:
751 			/* PC-relative; 22 bits */
752 			DEBUGP("PCREL22F Symbol %s loc %p val %lx\n",
753 			       strtab + sym->st_name,
754 			       loc, val);
755 			val += addend;
756 			/* can we reach it locally? */
757 			if (in_local(me, (void *)val)) {
758 				/* this is the case where the symbol is local
759 				 * to the module, but in a different section,
760 				 * so stub the jump in case it's more than 22
761 				 * bits away */
762 				val = (val - dot - 8)/4;
763 				if (!RELOC_REACHABLE(val, 22)) {
764 					/* direct distance too far, create
765 					 * stub entry instead */
766 					val = get_stub(me, sym->st_value,
767 						addend, ELF_STUB_DIRECT,
768 						loc0, targetsec);
769 				} else {
770 					/* Ok, we can reach it directly. */
771 					val = sym->st_value;
772 					val += addend;
773 				}
774 			} else {
775 				val = sym->st_value;
776 				if (strncmp(strtab + sym->st_name, "$$", 2)
777 				    == 0)
778 					val = get_stub(me, val, addend, ELF_STUB_MILLI,
779 						       loc0, targetsec);
780 				else
781 					val = get_stub(me, val, addend, ELF_STUB_GOT,
782 						       loc0, targetsec);
783 			}
784 			DEBUGP("STUB FOR %s loc %lx, val %lx+%lx at %lx\n",
785 			       strtab + sym->st_name, loc, sym->st_value,
786 			       addend, val);
787 			val = (val - dot - 8)/4;
788 			CHECK_RELOC(val, 22);
789 			*loc = (*loc & ~0x3ff1ffd) | reassemble_22(val);
790 			break;
791 		case R_PARISC_DIR64:
792 			/* 64-bit effective address */
793 			*loc64 = val + addend;
794 			break;
795 		case R_PARISC_SEGREL32:
796 			/* 32-bit segment relative address */
797 			/* See note about special handling of SEGREL32 at
798 			 * the beginning of this file.
799 			 */
800 			*loc = fsel(val, addend);
801 			break;
802 		case R_PARISC_FPTR64:
803 			/* 64-bit function address */
804 			if(in_local(me, (void *)(val + addend))) {
805 				*loc64 = get_fdesc(me, val+addend);
806 				DEBUGP("FDESC for %s at %p points to %lx\n",
807 				       strtab + sym->st_name, *loc64,
808 				       ((Elf_Fdesc *)*loc64)->addr);
809 			} else {
810 				/* if the symbol is not local to this
811 				 * module then val+addend is a pointer
812 				 * to the function descriptor */
813 				DEBUGP("Non local FPTR64 Symbol %s loc %p val %lx\n",
814 				       strtab + sym->st_name,
815 				       loc, val);
816 				*loc64 = val + addend;
817 			}
818 			break;
819 
820 		default:
821 			printk(KERN_ERR "module %s: Unknown relocation: %Lu\n",
822 			       me->name, ELF64_R_TYPE(rel[i].r_info));
823 			return -ENOEXEC;
824 		}
825 	}
826 	return 0;
827 }
828 #endif
829 
830 static void
831 register_unwind_table(struct module *me,
832 		      const Elf_Shdr *sechdrs)
833 {
834 	unsigned char *table, *end;
835 	unsigned long gp;
836 
837 	if (!me->arch.unwind_section)
838 		return;
839 
840 	table = (unsigned char *)sechdrs[me->arch.unwind_section].sh_addr;
841 	end = table + sechdrs[me->arch.unwind_section].sh_size;
842 	gp = (Elf_Addr)me->module_core + me->arch.got_offset;
843 
844 	DEBUGP("register_unwind_table(), sect = %d at 0x%p - 0x%p (gp=0x%lx)\n",
845 	       me->arch.unwind_section, table, end, gp);
846 	me->arch.unwind = unwind_table_add(me->name, 0, gp, table, end);
847 }
848 
849 static void
850 deregister_unwind_table(struct module *me)
851 {
852 	if (me->arch.unwind)
853 		unwind_table_remove(me->arch.unwind);
854 }
855 
856 int module_finalize(const Elf_Ehdr *hdr,
857 		    const Elf_Shdr *sechdrs,
858 		    struct module *me)
859 {
860 	int i;
861 	unsigned long nsyms;
862 	const char *strtab = NULL;
863 	Elf_Sym *newptr, *oldptr;
864 	Elf_Shdr *symhdr = NULL;
865 #ifdef DEBUG
866 	Elf_Fdesc *entry;
867 	u32 *addr;
868 
869 	entry = (Elf_Fdesc *)me->init;
870 	printk("FINALIZE, ->init FPTR is %p, GP %lx ADDR %lx\n", entry,
871 	       entry->gp, entry->addr);
872 	addr = (u32 *)entry->addr;
873 	printk("INSNS: %x %x %x %x\n",
874 	       addr[0], addr[1], addr[2], addr[3]);
875 	printk("got entries used %ld, gots max %ld\n"
876 	       "fdescs used %ld, fdescs max %ld\n",
877 	       me->arch.got_count, me->arch.got_max,
878 	       me->arch.fdesc_count, me->arch.fdesc_max);
879 #endif
880 
881 	register_unwind_table(me, sechdrs);
882 
883 	/* haven't filled in me->symtab yet, so have to find it
884 	 * ourselves */
885 	for (i = 1; i < hdr->e_shnum; i++) {
886 		if(sechdrs[i].sh_type == SHT_SYMTAB
887 		   && (sechdrs[i].sh_flags & SHF_ALLOC)) {
888 			int strindex = sechdrs[i].sh_link;
889 			/* FIXME: AWFUL HACK
890 			 * The cast is to drop the const from
891 			 * the sechdrs pointer */
892 			symhdr = (Elf_Shdr *)&sechdrs[i];
893 			strtab = (char *)sechdrs[strindex].sh_addr;
894 			break;
895 		}
896 	}
897 
898 	DEBUGP("module %s: strtab %p, symhdr %p\n",
899 	       me->name, strtab, symhdr);
900 
901 	if(me->arch.got_count > MAX_GOTS) {
902 		printk(KERN_ERR "%s: Global Offset Table overflow (used %ld, allowed %d)\n",
903 				me->name, me->arch.got_count, MAX_GOTS);
904 		return -EINVAL;
905 	}
906 
907 	kfree(me->arch.section);
908 	me->arch.section = NULL;
909 
910 	/* no symbol table */
911 	if(symhdr == NULL)
912 		return 0;
913 
914 	oldptr = (void *)symhdr->sh_addr;
915 	newptr = oldptr + 1;	/* we start counting at 1 */
916 	nsyms = symhdr->sh_size / sizeof(Elf_Sym);
917 	DEBUGP("OLD num_symtab %lu\n", nsyms);
918 
919 	for (i = 1; i < nsyms; i++) {
920 		oldptr++;	/* note, count starts at 1 so preincrement */
921 		if(strncmp(strtab + oldptr->st_name,
922 			      ".L", 2) == 0)
923 			continue;
924 
925 		if(newptr != oldptr)
926 			*newptr++ = *oldptr;
927 		else
928 			newptr++;
929 
930 	}
931 	nsyms = newptr - (Elf_Sym *)symhdr->sh_addr;
932 	DEBUGP("NEW num_symtab %lu\n", nsyms);
933 	symhdr->sh_size = nsyms * sizeof(Elf_Sym);
934 	return 0;
935 }
936 
937 void module_arch_cleanup(struct module *mod)
938 {
939 	deregister_unwind_table(mod);
940 }
941