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awilliam
GitHub Repository: awilliam/linux-vfio
Path: blob/master/arch/parisc/kernel/module.c
10817 views
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 <[email protected]>
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
int apply_relocate(Elf_Shdr *sechdrs,
544
const char *strtab,
545
unsigned int symindex,
546
unsigned int relsec,
547
struct module *me)
548
{
549
/* parisc should not need this ... */
550
printk(KERN_ERR "module %s: RELOCATION unsupported\n",
551
me->name);
552
return -ENOEXEC;
553
}
554
555
#ifndef CONFIG_64BIT
556
int apply_relocate_add(Elf_Shdr *sechdrs,
557
const char *strtab,
558
unsigned int symindex,
559
unsigned int relsec,
560
struct module *me)
561
{
562
int i;
563
Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
564
Elf32_Sym *sym;
565
Elf32_Word *loc;
566
Elf32_Addr val;
567
Elf32_Sword addend;
568
Elf32_Addr dot;
569
Elf_Addr loc0;
570
unsigned int targetsec = sechdrs[relsec].sh_info;
571
//unsigned long dp = (unsigned long)$global$;
572
register unsigned long dp asm ("r27");
573
574
DEBUGP("Applying relocate section %u to %u\n", relsec,
575
targetsec);
576
for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
577
/* This is where to make the change */
578
loc = (void *)sechdrs[targetsec].sh_addr
579
+ rel[i].r_offset;
580
/* This is the start of the target section */
581
loc0 = sechdrs[targetsec].sh_addr;
582
/* This is the symbol it is referring to */
583
sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
584
+ ELF32_R_SYM(rel[i].r_info);
585
if (!sym->st_value) {
586
printk(KERN_WARNING "%s: Unknown symbol %s\n",
587
me->name, strtab + sym->st_name);
588
return -ENOENT;
589
}
590
//dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03;
591
dot = (Elf32_Addr)loc & ~0x03;
592
593
val = sym->st_value;
594
addend = rel[i].r_addend;
595
596
#if 0
597
#define r(t) ELF32_R_TYPE(rel[i].r_info)==t ? #t :
598
DEBUGP("Symbol %s loc 0x%x val 0x%x addend 0x%x: %s\n",
599
strtab + sym->st_name,
600
(uint32_t)loc, val, addend,
601
r(R_PARISC_PLABEL32)
602
r(R_PARISC_DIR32)
603
r(R_PARISC_DIR21L)
604
r(R_PARISC_DIR14R)
605
r(R_PARISC_SEGREL32)
606
r(R_PARISC_DPREL21L)
607
r(R_PARISC_DPREL14R)
608
r(R_PARISC_PCREL17F)
609
r(R_PARISC_PCREL22F)
610
"UNKNOWN");
611
#undef r
612
#endif
613
614
switch (ELF32_R_TYPE(rel[i].r_info)) {
615
case R_PARISC_PLABEL32:
616
/* 32-bit function address */
617
/* no function descriptors... */
618
*loc = fsel(val, addend);
619
break;
620
case R_PARISC_DIR32:
621
/* direct 32-bit ref */
622
*loc = fsel(val, addend);
623
break;
624
case R_PARISC_DIR21L:
625
/* left 21 bits of effective address */
626
val = lrsel(val, addend);
627
*loc = mask(*loc, 21) | reassemble_21(val);
628
break;
629
case R_PARISC_DIR14R:
630
/* right 14 bits of effective address */
631
val = rrsel(val, addend);
632
*loc = mask(*loc, 14) | reassemble_14(val);
633
break;
634
case R_PARISC_SEGREL32:
635
/* 32-bit segment relative address */
636
/* See note about special handling of SEGREL32 at
637
* the beginning of this file.
638
*/
639
*loc = fsel(val, addend);
640
break;
641
case R_PARISC_DPREL21L:
642
/* left 21 bit of relative address */
643
val = lrsel(val - dp, addend);
644
*loc = mask(*loc, 21) | reassemble_21(val);
645
break;
646
case R_PARISC_DPREL14R:
647
/* right 14 bit of relative address */
648
val = rrsel(val - dp, addend);
649
*loc = mask(*loc, 14) | reassemble_14(val);
650
break;
651
case R_PARISC_PCREL17F:
652
/* 17-bit PC relative address */
653
/* calculate direct call offset */
654
val += addend;
655
val = (val - dot - 8)/4;
656
if (!RELOC_REACHABLE(val, 17)) {
657
/* direct distance too far, create
658
* stub entry instead */
659
val = get_stub(me, sym->st_value, addend,
660
ELF_STUB_DIRECT, loc0, targetsec);
661
val = (val - dot - 8)/4;
662
CHECK_RELOC(val, 17);
663
}
664
*loc = (*loc & ~0x1f1ffd) | reassemble_17(val);
665
break;
666
case R_PARISC_PCREL22F:
667
/* 22-bit PC relative address; only defined for pa20 */
668
/* calculate direct call offset */
669
val += addend;
670
val = (val - dot - 8)/4;
671
if (!RELOC_REACHABLE(val, 22)) {
672
/* direct distance too far, create
673
* stub entry instead */
674
val = get_stub(me, sym->st_value, addend,
675
ELF_STUB_DIRECT, loc0, targetsec);
676
val = (val - dot - 8)/4;
677
CHECK_RELOC(val, 22);
678
}
679
*loc = (*loc & ~0x3ff1ffd) | reassemble_22(val);
680
break;
681
682
default:
683
printk(KERN_ERR "module %s: Unknown relocation: %u\n",
684
me->name, ELF32_R_TYPE(rel[i].r_info));
685
return -ENOEXEC;
686
}
687
}
688
689
return 0;
690
}
691
692
#else
693
int apply_relocate_add(Elf_Shdr *sechdrs,
694
const char *strtab,
695
unsigned int symindex,
696
unsigned int relsec,
697
struct module *me)
698
{
699
int i;
700
Elf64_Rela *rel = (void *)sechdrs[relsec].sh_addr;
701
Elf64_Sym *sym;
702
Elf64_Word *loc;
703
Elf64_Xword *loc64;
704
Elf64_Addr val;
705
Elf64_Sxword addend;
706
Elf64_Addr dot;
707
Elf_Addr loc0;
708
unsigned int targetsec = sechdrs[relsec].sh_info;
709
710
DEBUGP("Applying relocate section %u to %u\n", relsec,
711
targetsec);
712
for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
713
/* This is where to make the change */
714
loc = (void *)sechdrs[targetsec].sh_addr
715
+ rel[i].r_offset;
716
/* This is the start of the target section */
717
loc0 = sechdrs[targetsec].sh_addr;
718
/* This is the symbol it is referring to */
719
sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
720
+ ELF64_R_SYM(rel[i].r_info);
721
if (!sym->st_value) {
722
printk(KERN_WARNING "%s: Unknown symbol %s\n",
723
me->name, strtab + sym->st_name);
724
return -ENOENT;
725
}
726
//dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03;
727
dot = (Elf64_Addr)loc & ~0x03;
728
loc64 = (Elf64_Xword *)loc;
729
730
val = sym->st_value;
731
addend = rel[i].r_addend;
732
733
#if 0
734
#define r(t) ELF64_R_TYPE(rel[i].r_info)==t ? #t :
735
printk("Symbol %s loc %p val 0x%Lx addend 0x%Lx: %s\n",
736
strtab + sym->st_name,
737
loc, val, addend,
738
r(R_PARISC_LTOFF14R)
739
r(R_PARISC_LTOFF21L)
740
r(R_PARISC_PCREL22F)
741
r(R_PARISC_DIR64)
742
r(R_PARISC_SEGREL32)
743
r(R_PARISC_FPTR64)
744
"UNKNOWN");
745
#undef r
746
#endif
747
748
switch (ELF64_R_TYPE(rel[i].r_info)) {
749
case R_PARISC_LTOFF21L:
750
/* LT-relative; left 21 bits */
751
val = get_got(me, val, addend);
752
DEBUGP("LTOFF21L Symbol %s loc %p val %lx\n",
753
strtab + sym->st_name,
754
loc, val);
755
val = lrsel(val, 0);
756
*loc = mask(*loc, 21) | reassemble_21(val);
757
break;
758
case R_PARISC_LTOFF14R:
759
/* L(ltoff(val+addend)) */
760
/* LT-relative; right 14 bits */
761
val = get_got(me, val, addend);
762
val = rrsel(val, 0);
763
DEBUGP("LTOFF14R Symbol %s loc %p val %lx\n",
764
strtab + sym->st_name,
765
loc, val);
766
*loc = mask(*loc, 14) | reassemble_14(val);
767
break;
768
case R_PARISC_PCREL22F:
769
/* PC-relative; 22 bits */
770
DEBUGP("PCREL22F Symbol %s loc %p val %lx\n",
771
strtab + sym->st_name,
772
loc, val);
773
val += addend;
774
/* can we reach it locally? */
775
if (in_local(me, (void *)val)) {
776
/* this is the case where the symbol is local
777
* to the module, but in a different section,
778
* so stub the jump in case it's more than 22
779
* bits away */
780
val = (val - dot - 8)/4;
781
if (!RELOC_REACHABLE(val, 22)) {
782
/* direct distance too far, create
783
* stub entry instead */
784
val = get_stub(me, sym->st_value,
785
addend, ELF_STUB_DIRECT,
786
loc0, targetsec);
787
} else {
788
/* Ok, we can reach it directly. */
789
val = sym->st_value;
790
val += addend;
791
}
792
} else {
793
val = sym->st_value;
794
if (strncmp(strtab + sym->st_name, "$$", 2)
795
== 0)
796
val = get_stub(me, val, addend, ELF_STUB_MILLI,
797
loc0, targetsec);
798
else
799
val = get_stub(me, val, addend, ELF_STUB_GOT,
800
loc0, targetsec);
801
}
802
DEBUGP("STUB FOR %s loc %lx, val %lx+%lx at %lx\n",
803
strtab + sym->st_name, loc, sym->st_value,
804
addend, val);
805
val = (val - dot - 8)/4;
806
CHECK_RELOC(val, 22);
807
*loc = (*loc & ~0x3ff1ffd) | reassemble_22(val);
808
break;
809
case R_PARISC_DIR64:
810
/* 64-bit effective address */
811
*loc64 = val + addend;
812
break;
813
case R_PARISC_SEGREL32:
814
/* 32-bit segment relative address */
815
/* See note about special handling of SEGREL32 at
816
* the beginning of this file.
817
*/
818
*loc = fsel(val, addend);
819
break;
820
case R_PARISC_FPTR64:
821
/* 64-bit function address */
822
if(in_local(me, (void *)(val + addend))) {
823
*loc64 = get_fdesc(me, val+addend);
824
DEBUGP("FDESC for %s at %p points to %lx\n",
825
strtab + sym->st_name, *loc64,
826
((Elf_Fdesc *)*loc64)->addr);
827
} else {
828
/* if the symbol is not local to this
829
* module then val+addend is a pointer
830
* to the function descriptor */
831
DEBUGP("Non local FPTR64 Symbol %s loc %p val %lx\n",
832
strtab + sym->st_name,
833
loc, val);
834
*loc64 = val + addend;
835
}
836
break;
837
838
default:
839
printk(KERN_ERR "module %s: Unknown relocation: %Lu\n",
840
me->name, ELF64_R_TYPE(rel[i].r_info));
841
return -ENOEXEC;
842
}
843
}
844
return 0;
845
}
846
#endif
847
848
static void
849
register_unwind_table(struct module *me,
850
const Elf_Shdr *sechdrs)
851
{
852
unsigned char *table, *end;
853
unsigned long gp;
854
855
if (!me->arch.unwind_section)
856
return;
857
858
table = (unsigned char *)sechdrs[me->arch.unwind_section].sh_addr;
859
end = table + sechdrs[me->arch.unwind_section].sh_size;
860
gp = (Elf_Addr)me->module_core + me->arch.got_offset;
861
862
DEBUGP("register_unwind_table(), sect = %d at 0x%p - 0x%p (gp=0x%lx)\n",
863
me->arch.unwind_section, table, end, gp);
864
me->arch.unwind = unwind_table_add(me->name, 0, gp, table, end);
865
}
866
867
static void
868
deregister_unwind_table(struct module *me)
869
{
870
if (me->arch.unwind)
871
unwind_table_remove(me->arch.unwind);
872
}
873
874
int module_finalize(const Elf_Ehdr *hdr,
875
const Elf_Shdr *sechdrs,
876
struct module *me)
877
{
878
int i;
879
unsigned long nsyms;
880
const char *strtab = NULL;
881
Elf_Sym *newptr, *oldptr;
882
Elf_Shdr *symhdr = NULL;
883
#ifdef DEBUG
884
Elf_Fdesc *entry;
885
u32 *addr;
886
887
entry = (Elf_Fdesc *)me->init;
888
printk("FINALIZE, ->init FPTR is %p, GP %lx ADDR %lx\n", entry,
889
entry->gp, entry->addr);
890
addr = (u32 *)entry->addr;
891
printk("INSNS: %x %x %x %x\n",
892
addr[0], addr[1], addr[2], addr[3]);
893
printk("got entries used %ld, gots max %ld\n"
894
"fdescs used %ld, fdescs max %ld\n",
895
me->arch.got_count, me->arch.got_max,
896
me->arch.fdesc_count, me->arch.fdesc_max);
897
#endif
898
899
register_unwind_table(me, sechdrs);
900
901
/* haven't filled in me->symtab yet, so have to find it
902
* ourselves */
903
for (i = 1; i < hdr->e_shnum; i++) {
904
if(sechdrs[i].sh_type == SHT_SYMTAB
905
&& (sechdrs[i].sh_flags & SHF_ALLOC)) {
906
int strindex = sechdrs[i].sh_link;
907
/* FIXME: AWFUL HACK
908
* The cast is to drop the const from
909
* the sechdrs pointer */
910
symhdr = (Elf_Shdr *)&sechdrs[i];
911
strtab = (char *)sechdrs[strindex].sh_addr;
912
break;
913
}
914
}
915
916
DEBUGP("module %s: strtab %p, symhdr %p\n",
917
me->name, strtab, symhdr);
918
919
if(me->arch.got_count > MAX_GOTS) {
920
printk(KERN_ERR "%s: Global Offset Table overflow (used %ld, allowed %d)\n",
921
me->name, me->arch.got_count, MAX_GOTS);
922
return -EINVAL;
923
}
924
925
kfree(me->arch.section);
926
me->arch.section = NULL;
927
928
/* no symbol table */
929
if(symhdr == NULL)
930
return 0;
931
932
oldptr = (void *)symhdr->sh_addr;
933
newptr = oldptr + 1; /* we start counting at 1 */
934
nsyms = symhdr->sh_size / sizeof(Elf_Sym);
935
DEBUGP("OLD num_symtab %lu\n", nsyms);
936
937
for (i = 1; i < nsyms; i++) {
938
oldptr++; /* note, count starts at 1 so preincrement */
939
if(strncmp(strtab + oldptr->st_name,
940
".L", 2) == 0)
941
continue;
942
943
if(newptr != oldptr)
944
*newptr++ = *oldptr;
945
else
946
newptr++;
947
948
}
949
nsyms = newptr - (Elf_Sym *)symhdr->sh_addr;
950
DEBUGP("NEW num_symtab %lu\n", nsyms);
951
symhdr->sh_size = nsyms * sizeof(Elf_Sym);
952
return 0;
953
}
954
955
void module_arch_cleanup(struct module *mod)
956
{
957
deregister_unwind_table(mod);
958
}
959
960