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 |
80 | struct got_entry { |
81 | Elf32_Addr addr; |
82 | }; |
83 | |
84 | struct stub_entry { |
85 | Elf32_Word insns[2]; /* each stub entry has two insns */ |
86 | }; |
87 | #else |
88 | struct got_entry { |
89 | Elf64_Addr addr; |
90 | }; |
91 | |
92 | struct 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. */ |
116 | static 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 | |
124 | static 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 | |
133 | static inline int reassemble_14(int as14) |
134 | { |
135 | return (((as14 & 0x1fff) << 1) | |
136 | ((as14 & 0x2000) >> 13)); |
137 | } |
138 | |
139 | static 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 | |
150 | static 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 | |
158 | static 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 | |
167 | static 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 | |
176 | void *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 |
188 | static inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n) |
189 | { |
190 | return 0; |
191 | } |
192 | |
193 | static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n) |
194 | { |
195 | return 0; |
196 | } |
197 | |
198 | static 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 |
214 | static 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 | |
231 | static 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 | |
246 | static 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 | |
262 | void 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 */ |
269 | unsigned 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 |
279 | int 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 |
348 | static 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 |
373 | static 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 | |
398 | enum elf_stub_type { |
399 | ELF_STUB_GOT, |
400 | ELF_STUB_MILLI, |
401 | ELF_STUB_DIRECT, |
402 | }; |
403 | |
404 | static 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 |
501 | int 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 |
646 | int 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 | |
813 | static void |
814 | register_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 | |
832 | static void |
833 | deregister_unwind_table(struct module *me) |
834 | { |
835 | if (me->arch.unwind) |
836 | unwind_table_remove(me->arch.unwind); |
837 | } |
838 | |
839 | int 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 | |
955 | void module_arch_cleanup(struct module *mod) |
956 | { |
957 | deregister_unwind_table(me: mod); |
958 | } |
959 | |
960 | #ifdef CONFIG_64BIT |
961 | void *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 | |