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

source code of linux/arch/parisc/kernel/module.c