xref: /openbmc/linux/arch/parisc/kernel/module.c (revision 1ab142d4)
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 	if (size == 0)
218 		return NULL;
219 	/* using RWX means less protection for modules, but it's
220 	 * easier than trying to map the text, data, init_text and
221 	 * init_data correctly */
222 	return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
223 				    GFP_KERNEL | __GFP_HIGHMEM,
224 				    PAGE_KERNEL_RWX, -1,
225 				    __builtin_return_address(0));
226 }
227 
228 #ifndef CONFIG_64BIT
229 static inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n)
230 {
231 	return 0;
232 }
233 
234 static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n)
235 {
236 	return 0;
237 }
238 
239 static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n)
240 {
241 	unsigned long cnt = 0;
242 
243 	for (; n > 0; n--, rela++)
244 	{
245 		switch (ELF32_R_TYPE(rela->r_info)) {
246 			case R_PARISC_PCREL17F:
247 			case R_PARISC_PCREL22F:
248 				cnt++;
249 		}
250 	}
251 
252 	return cnt;
253 }
254 #else
255 static inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n)
256 {
257 	unsigned long cnt = 0;
258 
259 	for (; n > 0; n--, rela++)
260 	{
261 		switch (ELF64_R_TYPE(rela->r_info)) {
262 			case R_PARISC_LTOFF21L:
263 			case R_PARISC_LTOFF14R:
264 			case R_PARISC_PCREL22F:
265 				cnt++;
266 		}
267 	}
268 
269 	return cnt;
270 }
271 
272 static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n)
273 {
274 	unsigned long cnt = 0;
275 
276 	for (; n > 0; n--, rela++)
277 	{
278 		switch (ELF64_R_TYPE(rela->r_info)) {
279 			case R_PARISC_FPTR64:
280 				cnt++;
281 		}
282 	}
283 
284 	return cnt;
285 }
286 
287 static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n)
288 {
289 	unsigned long cnt = 0;
290 
291 	for (; n > 0; n--, rela++)
292 	{
293 		switch (ELF64_R_TYPE(rela->r_info)) {
294 			case R_PARISC_PCREL22F:
295 				cnt++;
296 		}
297 	}
298 
299 	return cnt;
300 }
301 #endif
302 
303 
304 /* Free memory returned from module_alloc */
305 void module_free(struct module *mod, void *module_region)
306 {
307 	kfree(mod->arch.section);
308 	mod->arch.section = NULL;
309 
310 	vfree(module_region);
311 }
312 
313 /* Additional bytes needed in front of individual sections */
314 unsigned int arch_mod_section_prepend(struct module *mod,
315 				      unsigned int section)
316 {
317 	/* size needed for all stubs of this section (including
318 	 * one additional for correct alignment of the stubs) */
319 	return (mod->arch.section[section].stub_entries + 1)
320 		* sizeof(struct stub_entry);
321 }
322 
323 #define CONST
324 int module_frob_arch_sections(CONST Elf_Ehdr *hdr,
325 			      CONST Elf_Shdr *sechdrs,
326 			      CONST char *secstrings,
327 			      struct module *me)
328 {
329 	unsigned long gots = 0, fdescs = 0, len;
330 	unsigned int i;
331 
332 	len = hdr->e_shnum * sizeof(me->arch.section[0]);
333 	me->arch.section = kzalloc(len, GFP_KERNEL);
334 	if (!me->arch.section)
335 		return -ENOMEM;
336 
337 	for (i = 1; i < hdr->e_shnum; i++) {
338 		const Elf_Rela *rels = (void *)sechdrs[i].sh_addr;
339 		unsigned long nrels = sechdrs[i].sh_size / sizeof(*rels);
340 		unsigned int count, s;
341 
342 		if (strncmp(secstrings + sechdrs[i].sh_name,
343 			    ".PARISC.unwind", 14) == 0)
344 			me->arch.unwind_section = i;
345 
346 		if (sechdrs[i].sh_type != SHT_RELA)
347 			continue;
348 
349 		/* some of these are not relevant for 32-bit/64-bit
350 		 * we leave them here to make the code common. the
351 		 * compiler will do its thing and optimize out the
352 		 * stuff we don't need
353 		 */
354 		gots += count_gots(rels, nrels);
355 		fdescs += count_fdescs(rels, nrels);
356 
357 		/* XXX: By sorting the relocs and finding duplicate entries
358 		 *  we could reduce the number of necessary stubs and save
359 		 *  some memory. */
360 		count = count_stubs(rels, nrels);
361 		if (!count)
362 			continue;
363 
364 		/* so we need relocation stubs. reserve necessary memory. */
365 		/* sh_info gives the section for which we need to add stubs. */
366 		s = sechdrs[i].sh_info;
367 
368 		/* each code section should only have one relocation section */
369 		WARN_ON(me->arch.section[s].stub_entries);
370 
371 		/* store number of stubs we need for this section */
372 		me->arch.section[s].stub_entries += count;
373 	}
374 
375 	/* align things a bit */
376 	me->core_size = ALIGN(me->core_size, 16);
377 	me->arch.got_offset = me->core_size;
378 	me->core_size += gots * sizeof(struct got_entry);
379 
380 	me->core_size = ALIGN(me->core_size, 16);
381 	me->arch.fdesc_offset = me->core_size;
382 	me->core_size += fdescs * sizeof(Elf_Fdesc);
383 
384 	me->arch.got_max = gots;
385 	me->arch.fdesc_max = fdescs;
386 
387 	return 0;
388 }
389 
390 #ifdef CONFIG_64BIT
391 static Elf64_Word get_got(struct module *me, unsigned long value, long addend)
392 {
393 	unsigned int i;
394 	struct got_entry *got;
395 
396 	value += addend;
397 
398 	BUG_ON(value == 0);
399 
400 	got = me->module_core + me->arch.got_offset;
401 	for (i = 0; got[i].addr; i++)
402 		if (got[i].addr == value)
403 			goto out;
404 
405 	BUG_ON(++me->arch.got_count > me->arch.got_max);
406 
407 	got[i].addr = value;
408  out:
409 	DEBUGP("GOT ENTRY %d[%x] val %lx\n", i, i*sizeof(struct got_entry),
410 	       value);
411 	return i * sizeof(struct got_entry);
412 }
413 #endif /* CONFIG_64BIT */
414 
415 #ifdef CONFIG_64BIT
416 static Elf_Addr get_fdesc(struct module *me, unsigned long value)
417 {
418 	Elf_Fdesc *fdesc = me->module_core + me->arch.fdesc_offset;
419 
420 	if (!value) {
421 		printk(KERN_ERR "%s: zero OPD requested!\n", me->name);
422 		return 0;
423 	}
424 
425 	/* Look for existing fdesc entry. */
426 	while (fdesc->addr) {
427 		if (fdesc->addr == value)
428 			return (Elf_Addr)fdesc;
429 		fdesc++;
430 	}
431 
432 	BUG_ON(++me->arch.fdesc_count > me->arch.fdesc_max);
433 
434 	/* Create new one */
435 	fdesc->addr = value;
436 	fdesc->gp = (Elf_Addr)me->module_core + me->arch.got_offset;
437 	return (Elf_Addr)fdesc;
438 }
439 #endif /* CONFIG_64BIT */
440 
441 enum elf_stub_type {
442 	ELF_STUB_GOT,
443 	ELF_STUB_MILLI,
444 	ELF_STUB_DIRECT,
445 };
446 
447 static Elf_Addr get_stub(struct module *me, unsigned long value, long addend,
448 	enum elf_stub_type stub_type, Elf_Addr loc0, unsigned int targetsec)
449 {
450 	struct stub_entry *stub;
451 	int __maybe_unused d;
452 
453 	/* initialize stub_offset to point in front of the section */
454 	if (!me->arch.section[targetsec].stub_offset) {
455 		loc0 -= (me->arch.section[targetsec].stub_entries + 1) *
456 				sizeof(struct stub_entry);
457 		/* get correct alignment for the stubs */
458 		loc0 = ALIGN(loc0, sizeof(struct stub_entry));
459 		me->arch.section[targetsec].stub_offset = loc0;
460 	}
461 
462 	/* get address of stub entry */
463 	stub = (void *) me->arch.section[targetsec].stub_offset;
464 	me->arch.section[targetsec].stub_offset += sizeof(struct stub_entry);
465 
466 	/* do not write outside available stub area */
467 	BUG_ON(0 == me->arch.section[targetsec].stub_entries--);
468 
469 
470 #ifndef CONFIG_64BIT
471 /* for 32-bit the stub looks like this:
472  * 	ldil L'XXX,%r1
473  * 	be,n R'XXX(%sr4,%r1)
474  */
475 	//value = *(unsigned long *)((value + addend) & ~3); /* why? */
476 
477 	stub->insns[0] = 0x20200000;	/* ldil L'XXX,%r1	*/
478 	stub->insns[1] = 0xe0202002;	/* be,n R'XXX(%sr4,%r1)	*/
479 
480 	stub->insns[0] |= reassemble_21(lrsel(value, addend));
481 	stub->insns[1] |= reassemble_17(rrsel(value, addend) / 4);
482 
483 #else
484 /* for 64-bit we have three kinds of stubs:
485  * for normal function calls:
486  * 	ldd 0(%dp),%dp
487  * 	ldd 10(%dp), %r1
488  * 	bve (%r1)
489  * 	ldd 18(%dp), %dp
490  *
491  * for millicode:
492  * 	ldil 0, %r1
493  * 	ldo 0(%r1), %r1
494  * 	ldd 10(%r1), %r1
495  * 	bve,n (%r1)
496  *
497  * for direct branches (jumps between different section of the
498  * same module):
499  *	ldil 0, %r1
500  *	ldo 0(%r1), %r1
501  *	bve,n (%r1)
502  */
503 	switch (stub_type) {
504 	case ELF_STUB_GOT:
505 		d = get_got(me, value, addend);
506 		if (d <= 15) {
507 			/* Format 5 */
508 			stub->insns[0] = 0x0f6010db; /* ldd 0(%dp),%dp	*/
509 			stub->insns[0] |= low_sign_unext(d, 5) << 16;
510 		} else {
511 			/* Format 3 */
512 			stub->insns[0] = 0x537b0000; /* ldd 0(%dp),%dp	*/
513 			stub->insns[0] |= reassemble_16a(d);
514 		}
515 		stub->insns[1] = 0x53610020;	/* ldd 10(%dp),%r1	*/
516 		stub->insns[2] = 0xe820d000;	/* bve (%r1)		*/
517 		stub->insns[3] = 0x537b0030;	/* ldd 18(%dp),%dp	*/
518 		break;
519 	case ELF_STUB_MILLI:
520 		stub->insns[0] = 0x20200000;	/* ldil 0,%r1		*/
521 		stub->insns[1] = 0x34210000;	/* ldo 0(%r1), %r1	*/
522 		stub->insns[2] = 0x50210020;	/* ldd 10(%r1),%r1	*/
523 		stub->insns[3] = 0xe820d002;	/* bve,n (%r1)		*/
524 
525 		stub->insns[0] |= reassemble_21(lrsel(value, addend));
526 		stub->insns[1] |= reassemble_14(rrsel(value, addend));
527 		break;
528 	case ELF_STUB_DIRECT:
529 		stub->insns[0] = 0x20200000;    /* ldil 0,%r1           */
530 		stub->insns[1] = 0x34210000;    /* ldo 0(%r1), %r1      */
531 		stub->insns[2] = 0xe820d002;    /* bve,n (%r1)          */
532 
533 		stub->insns[0] |= reassemble_21(lrsel(value, addend));
534 		stub->insns[1] |= reassemble_14(rrsel(value, addend));
535 		break;
536 	}
537 
538 #endif
539 
540 	return (Elf_Addr)stub;
541 }
542 
543 #ifndef CONFIG_64BIT
544 int apply_relocate_add(Elf_Shdr *sechdrs,
545 		       const char *strtab,
546 		       unsigned int symindex,
547 		       unsigned int relsec,
548 		       struct module *me)
549 {
550 	int i;
551 	Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
552 	Elf32_Sym *sym;
553 	Elf32_Word *loc;
554 	Elf32_Addr val;
555 	Elf32_Sword addend;
556 	Elf32_Addr dot;
557 	Elf_Addr loc0;
558 	unsigned int targetsec = sechdrs[relsec].sh_info;
559 	//unsigned long dp = (unsigned long)$global$;
560 	register unsigned long dp asm ("r27");
561 
562 	DEBUGP("Applying relocate section %u to %u\n", relsec,
563 	       targetsec);
564 	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
565 		/* This is where to make the change */
566 		loc = (void *)sechdrs[targetsec].sh_addr
567 		      + rel[i].r_offset;
568 		/* This is the start of the target section */
569 		loc0 = sechdrs[targetsec].sh_addr;
570 		/* This is the symbol it is referring to */
571 		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
572 			+ ELF32_R_SYM(rel[i].r_info);
573 		if (!sym->st_value) {
574 			printk(KERN_WARNING "%s: Unknown symbol %s\n",
575 			       me->name, strtab + sym->st_name);
576 			return -ENOENT;
577 		}
578 		//dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03;
579 		dot =  (Elf32_Addr)loc & ~0x03;
580 
581 		val = sym->st_value;
582 		addend = rel[i].r_addend;
583 
584 #if 0
585 #define r(t) ELF32_R_TYPE(rel[i].r_info)==t ? #t :
586 		DEBUGP("Symbol %s loc 0x%x val 0x%x addend 0x%x: %s\n",
587 			strtab + sym->st_name,
588 			(uint32_t)loc, val, addend,
589 			r(R_PARISC_PLABEL32)
590 			r(R_PARISC_DIR32)
591 			r(R_PARISC_DIR21L)
592 			r(R_PARISC_DIR14R)
593 			r(R_PARISC_SEGREL32)
594 			r(R_PARISC_DPREL21L)
595 			r(R_PARISC_DPREL14R)
596 			r(R_PARISC_PCREL17F)
597 			r(R_PARISC_PCREL22F)
598 			"UNKNOWN");
599 #undef r
600 #endif
601 
602 		switch (ELF32_R_TYPE(rel[i].r_info)) {
603 		case R_PARISC_PLABEL32:
604 			/* 32-bit function address */
605 			/* no function descriptors... */
606 			*loc = fsel(val, addend);
607 			break;
608 		case R_PARISC_DIR32:
609 			/* direct 32-bit ref */
610 			*loc = fsel(val, addend);
611 			break;
612 		case R_PARISC_DIR21L:
613 			/* left 21 bits of effective address */
614 			val = lrsel(val, addend);
615 			*loc = mask(*loc, 21) | reassemble_21(val);
616 			break;
617 		case R_PARISC_DIR14R:
618 			/* right 14 bits of effective address */
619 			val = rrsel(val, addend);
620 			*loc = mask(*loc, 14) | reassemble_14(val);
621 			break;
622 		case R_PARISC_SEGREL32:
623 			/* 32-bit segment relative address */
624 			/* See note about special handling of SEGREL32 at
625 			 * the beginning of this file.
626 			 */
627 			*loc = fsel(val, addend);
628 			break;
629 		case R_PARISC_DPREL21L:
630 			/* left 21 bit of relative address */
631 			val = lrsel(val - dp, addend);
632 			*loc = mask(*loc, 21) | reassemble_21(val);
633 			break;
634 		case R_PARISC_DPREL14R:
635 			/* right 14 bit of relative address */
636 			val = rrsel(val - dp, addend);
637 			*loc = mask(*loc, 14) | reassemble_14(val);
638 			break;
639 		case R_PARISC_PCREL17F:
640 			/* 17-bit PC relative address */
641 			/* calculate direct call offset */
642 			val += addend;
643 			val = (val - dot - 8)/4;
644 			if (!RELOC_REACHABLE(val, 17)) {
645 				/* direct distance too far, create
646 				 * stub entry instead */
647 				val = get_stub(me, sym->st_value, addend,
648 					ELF_STUB_DIRECT, loc0, targetsec);
649 				val = (val - dot - 8)/4;
650 				CHECK_RELOC(val, 17);
651 			}
652 			*loc = (*loc & ~0x1f1ffd) | reassemble_17(val);
653 			break;
654 		case R_PARISC_PCREL22F:
655 			/* 22-bit PC relative address; only defined for pa20 */
656 			/* calculate direct call offset */
657 			val += addend;
658 			val = (val - dot - 8)/4;
659 			if (!RELOC_REACHABLE(val, 22)) {
660 				/* direct distance too far, create
661 				 * stub entry instead */
662 				val = get_stub(me, sym->st_value, addend,
663 					ELF_STUB_DIRECT, loc0, targetsec);
664 				val = (val - dot - 8)/4;
665 				CHECK_RELOC(val, 22);
666 			}
667 			*loc = (*loc & ~0x3ff1ffd) | reassemble_22(val);
668 			break;
669 
670 		default:
671 			printk(KERN_ERR "module %s: Unknown relocation: %u\n",
672 			       me->name, ELF32_R_TYPE(rel[i].r_info));
673 			return -ENOEXEC;
674 		}
675 	}
676 
677 	return 0;
678 }
679 
680 #else
681 int apply_relocate_add(Elf_Shdr *sechdrs,
682 		       const char *strtab,
683 		       unsigned int symindex,
684 		       unsigned int relsec,
685 		       struct module *me)
686 {
687 	int i;
688 	Elf64_Rela *rel = (void *)sechdrs[relsec].sh_addr;
689 	Elf64_Sym *sym;
690 	Elf64_Word *loc;
691 	Elf64_Xword *loc64;
692 	Elf64_Addr val;
693 	Elf64_Sxword addend;
694 	Elf64_Addr dot;
695 	Elf_Addr loc0;
696 	unsigned int targetsec = sechdrs[relsec].sh_info;
697 
698 	DEBUGP("Applying relocate section %u to %u\n", relsec,
699 	       targetsec);
700 	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
701 		/* This is where to make the change */
702 		loc = (void *)sechdrs[targetsec].sh_addr
703 		      + rel[i].r_offset;
704 		/* This is the start of the target section */
705 		loc0 = sechdrs[targetsec].sh_addr;
706 		/* This is the symbol it is referring to */
707 		sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
708 			+ ELF64_R_SYM(rel[i].r_info);
709 		if (!sym->st_value) {
710 			printk(KERN_WARNING "%s: Unknown symbol %s\n",
711 			       me->name, strtab + sym->st_name);
712 			return -ENOENT;
713 		}
714 		//dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03;
715 		dot = (Elf64_Addr)loc & ~0x03;
716 		loc64 = (Elf64_Xword *)loc;
717 
718 		val = sym->st_value;
719 		addend = rel[i].r_addend;
720 
721 #if 0
722 #define r(t) ELF64_R_TYPE(rel[i].r_info)==t ? #t :
723 		printk("Symbol %s loc %p val 0x%Lx addend 0x%Lx: %s\n",
724 			strtab + sym->st_name,
725 			loc, val, addend,
726 			r(R_PARISC_LTOFF14R)
727 			r(R_PARISC_LTOFF21L)
728 			r(R_PARISC_PCREL22F)
729 			r(R_PARISC_DIR64)
730 			r(R_PARISC_SEGREL32)
731 			r(R_PARISC_FPTR64)
732 			"UNKNOWN");
733 #undef r
734 #endif
735 
736 		switch (ELF64_R_TYPE(rel[i].r_info)) {
737 		case R_PARISC_LTOFF21L:
738 			/* LT-relative; left 21 bits */
739 			val = get_got(me, val, addend);
740 			DEBUGP("LTOFF21L Symbol %s loc %p val %lx\n",
741 			       strtab + sym->st_name,
742 			       loc, val);
743 			val = lrsel(val, 0);
744 			*loc = mask(*loc, 21) | reassemble_21(val);
745 			break;
746 		case R_PARISC_LTOFF14R:
747 			/* L(ltoff(val+addend)) */
748 			/* LT-relative; right 14 bits */
749 			val = get_got(me, val, addend);
750 			val = rrsel(val, 0);
751 			DEBUGP("LTOFF14R Symbol %s loc %p val %lx\n",
752 			       strtab + sym->st_name,
753 			       loc, val);
754 			*loc = mask(*loc, 14) | reassemble_14(val);
755 			break;
756 		case R_PARISC_PCREL22F:
757 			/* PC-relative; 22 bits */
758 			DEBUGP("PCREL22F Symbol %s loc %p val %lx\n",
759 			       strtab + sym->st_name,
760 			       loc, val);
761 			val += addend;
762 			/* can we reach it locally? */
763 			if (in_local(me, (void *)val)) {
764 				/* this is the case where the symbol is local
765 				 * to the module, but in a different section,
766 				 * so stub the jump in case it's more than 22
767 				 * bits away */
768 				val = (val - dot - 8)/4;
769 				if (!RELOC_REACHABLE(val, 22)) {
770 					/* direct distance too far, create
771 					 * stub entry instead */
772 					val = get_stub(me, sym->st_value,
773 						addend, ELF_STUB_DIRECT,
774 						loc0, targetsec);
775 				} else {
776 					/* Ok, we can reach it directly. */
777 					val = sym->st_value;
778 					val += addend;
779 				}
780 			} else {
781 				val = sym->st_value;
782 				if (strncmp(strtab + sym->st_name, "$$", 2)
783 				    == 0)
784 					val = get_stub(me, val, addend, ELF_STUB_MILLI,
785 						       loc0, targetsec);
786 				else
787 					val = get_stub(me, val, addend, ELF_STUB_GOT,
788 						       loc0, targetsec);
789 			}
790 			DEBUGP("STUB FOR %s loc %lx, val %lx+%lx at %lx\n",
791 			       strtab + sym->st_name, loc, sym->st_value,
792 			       addend, val);
793 			val = (val - dot - 8)/4;
794 			CHECK_RELOC(val, 22);
795 			*loc = (*loc & ~0x3ff1ffd) | reassemble_22(val);
796 			break;
797 		case R_PARISC_DIR64:
798 			/* 64-bit effective address */
799 			*loc64 = val + addend;
800 			break;
801 		case R_PARISC_SEGREL32:
802 			/* 32-bit segment relative address */
803 			/* See note about special handling of SEGREL32 at
804 			 * the beginning of this file.
805 			 */
806 			*loc = fsel(val, addend);
807 			break;
808 		case R_PARISC_FPTR64:
809 			/* 64-bit function address */
810 			if(in_local(me, (void *)(val + addend))) {
811 				*loc64 = get_fdesc(me, val+addend);
812 				DEBUGP("FDESC for %s at %p points to %lx\n",
813 				       strtab + sym->st_name, *loc64,
814 				       ((Elf_Fdesc *)*loc64)->addr);
815 			} else {
816 				/* if the symbol is not local to this
817 				 * module then val+addend is a pointer
818 				 * to the function descriptor */
819 				DEBUGP("Non local FPTR64 Symbol %s loc %p val %lx\n",
820 				       strtab + sym->st_name,
821 				       loc, val);
822 				*loc64 = val + addend;
823 			}
824 			break;
825 
826 		default:
827 			printk(KERN_ERR "module %s: Unknown relocation: %Lu\n",
828 			       me->name, ELF64_R_TYPE(rel[i].r_info));
829 			return -ENOEXEC;
830 		}
831 	}
832 	return 0;
833 }
834 #endif
835 
836 static void
837 register_unwind_table(struct module *me,
838 		      const Elf_Shdr *sechdrs)
839 {
840 	unsigned char *table, *end;
841 	unsigned long gp;
842 
843 	if (!me->arch.unwind_section)
844 		return;
845 
846 	table = (unsigned char *)sechdrs[me->arch.unwind_section].sh_addr;
847 	end = table + sechdrs[me->arch.unwind_section].sh_size;
848 	gp = (Elf_Addr)me->module_core + me->arch.got_offset;
849 
850 	DEBUGP("register_unwind_table(), sect = %d at 0x%p - 0x%p (gp=0x%lx)\n",
851 	       me->arch.unwind_section, table, end, gp);
852 	me->arch.unwind = unwind_table_add(me->name, 0, gp, table, end);
853 }
854 
855 static void
856 deregister_unwind_table(struct module *me)
857 {
858 	if (me->arch.unwind)
859 		unwind_table_remove(me->arch.unwind);
860 }
861 
862 int module_finalize(const Elf_Ehdr *hdr,
863 		    const Elf_Shdr *sechdrs,
864 		    struct module *me)
865 {
866 	int i;
867 	unsigned long nsyms;
868 	const char *strtab = NULL;
869 	Elf_Sym *newptr, *oldptr;
870 	Elf_Shdr *symhdr = NULL;
871 #ifdef DEBUG
872 	Elf_Fdesc *entry;
873 	u32 *addr;
874 
875 	entry = (Elf_Fdesc *)me->init;
876 	printk("FINALIZE, ->init FPTR is %p, GP %lx ADDR %lx\n", entry,
877 	       entry->gp, entry->addr);
878 	addr = (u32 *)entry->addr;
879 	printk("INSNS: %x %x %x %x\n",
880 	       addr[0], addr[1], addr[2], addr[3]);
881 	printk("got entries used %ld, gots max %ld\n"
882 	       "fdescs used %ld, fdescs max %ld\n",
883 	       me->arch.got_count, me->arch.got_max,
884 	       me->arch.fdesc_count, me->arch.fdesc_max);
885 #endif
886 
887 	register_unwind_table(me, sechdrs);
888 
889 	/* haven't filled in me->symtab yet, so have to find it
890 	 * ourselves */
891 	for (i = 1; i < hdr->e_shnum; i++) {
892 		if(sechdrs[i].sh_type == SHT_SYMTAB
893 		   && (sechdrs[i].sh_flags & SHF_ALLOC)) {
894 			int strindex = sechdrs[i].sh_link;
895 			/* FIXME: AWFUL HACK
896 			 * The cast is to drop the const from
897 			 * the sechdrs pointer */
898 			symhdr = (Elf_Shdr *)&sechdrs[i];
899 			strtab = (char *)sechdrs[strindex].sh_addr;
900 			break;
901 		}
902 	}
903 
904 	DEBUGP("module %s: strtab %p, symhdr %p\n",
905 	       me->name, strtab, symhdr);
906 
907 	if(me->arch.got_count > MAX_GOTS) {
908 		printk(KERN_ERR "%s: Global Offset Table overflow (used %ld, allowed %d)\n",
909 				me->name, me->arch.got_count, MAX_GOTS);
910 		return -EINVAL;
911 	}
912 
913 	kfree(me->arch.section);
914 	me->arch.section = NULL;
915 
916 	/* no symbol table */
917 	if(symhdr == NULL)
918 		return 0;
919 
920 	oldptr = (void *)symhdr->sh_addr;
921 	newptr = oldptr + 1;	/* we start counting at 1 */
922 	nsyms = symhdr->sh_size / sizeof(Elf_Sym);
923 	DEBUGP("OLD num_symtab %lu\n", nsyms);
924 
925 	for (i = 1; i < nsyms; i++) {
926 		oldptr++;	/* note, count starts at 1 so preincrement */
927 		if(strncmp(strtab + oldptr->st_name,
928 			      ".L", 2) == 0)
929 			continue;
930 
931 		if(newptr != oldptr)
932 			*newptr++ = *oldptr;
933 		else
934 			newptr++;
935 
936 	}
937 	nsyms = newptr - (Elf_Sym *)symhdr->sh_addr;
938 	DEBUGP("NEW num_symtab %lu\n", nsyms);
939 	symhdr->sh_size = nsyms * sizeof(Elf_Sym);
940 	return 0;
941 }
942 
943 void module_arch_cleanup(struct module *mod)
944 {
945 	deregister_unwind_table(mod);
946 }
947