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1da177e4 LT |
1 | /* Kernel module help for PPC64. |
2 | Copyright (C) 2001, 2003 Rusty Russell IBM Corporation. | |
3 | ||
4 | This program is free software; you can redistribute it and/or modify | |
5 | it under the terms of the GNU General Public License as published by | |
6 | the Free Software Foundation; either version 2 of the License, or | |
7 | (at your option) any later version. | |
8 | ||
9 | This program is distributed in the hope that it will be useful, | |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | GNU General Public License for more details. | |
13 | ||
14 | You should have received a copy of the GNU General Public License | |
15 | along with this program; if not, write to the Free Software | |
16 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
17 | */ | |
c7d1f6af AB |
18 | |
19 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
20 | ||
1da177e4 LT |
21 | #include <linux/module.h> |
22 | #include <linux/elf.h> | |
23 | #include <linux/moduleloader.h> | |
24 | #include <linux/err.h> | |
25 | #include <linux/vmalloc.h> | |
f48cb8b4 | 26 | #include <linux/ftrace.h> |
73c9ceab | 27 | #include <linux/bug.h> |
83775b85 | 28 | #include <linux/uaccess.h> |
1da177e4 | 29 | #include <asm/module.h> |
21c4ff80 | 30 | #include <asm/firmware.h> |
b7bcda63 | 31 | #include <asm/code-patching.h> |
eda09fbd | 32 | #include <linux/sort.h> |
b88c4767 | 33 | #include <asm/setup.h> |
1da177e4 LT |
34 | |
35 | /* FIXME: We don't do .init separately. To do this, we'd need to have | |
36 | a separate r2 value in the init and core section, and stub between | |
37 | them, too. | |
38 | ||
39 | Using a magic allocator which places modules within 32MB solves | |
40 | this, and makes other things simpler. Anton? | |
41 | --RR. */ | |
1da177e4 | 42 | |
d2fae548 RR |
43 | #if defined(_CALL_ELF) && _CALL_ELF == 2 |
44 | #define R2_STACK_OFFSET 24 | |
008d7a91 RR |
45 | |
46 | /* An address is simply the address of the function. */ | |
47 | typedef unsigned long func_desc_t; | |
48 | ||
49 | static func_desc_t func_desc(unsigned long addr) | |
50 | { | |
51 | return addr; | |
52 | } | |
53 | static unsigned long func_addr(unsigned long addr) | |
54 | { | |
55 | return addr; | |
56 | } | |
57 | static unsigned long stub_func_addr(func_desc_t func) | |
58 | { | |
59 | return func; | |
60 | } | |
61 | ||
62 | /* PowerPC64 specific values for the Elf64_Sym st_other field. */ | |
63 | #define STO_PPC64_LOCAL_BIT 5 | |
64 | #define STO_PPC64_LOCAL_MASK (7 << STO_PPC64_LOCAL_BIT) | |
65 | #define PPC64_LOCAL_ENTRY_OFFSET(other) \ | |
66 | (((1 << (((other) & STO_PPC64_LOCAL_MASK) >> STO_PPC64_LOCAL_BIT)) >> 2) << 2) | |
67 | ||
68 | static unsigned int local_entry_offset(const Elf64_Sym *sym) | |
69 | { | |
70 | /* sym->st_other indicates offset to local entry point | |
71 | * (otherwise it will assume r12 is the address of the start | |
72 | * of function and try to derive r2 from it). */ | |
73 | return PPC64_LOCAL_ENTRY_OFFSET(sym->st_other); | |
74 | } | |
d2fae548 RR |
75 | #else |
76 | #define R2_STACK_OFFSET 40 | |
008d7a91 RR |
77 | |
78 | /* An address is address of the OPD entry, which contains address of fn. */ | |
79 | typedef struct ppc64_opd_entry func_desc_t; | |
80 | ||
81 | static func_desc_t func_desc(unsigned long addr) | |
82 | { | |
83 | return *(struct ppc64_opd_entry *)addr; | |
84 | } | |
85 | static unsigned long func_addr(unsigned long addr) | |
86 | { | |
87 | return func_desc(addr).funcaddr; | |
88 | } | |
89 | static unsigned long stub_func_addr(func_desc_t func) | |
90 | { | |
91 | return func.funcaddr; | |
92 | } | |
93 | static unsigned int local_entry_offset(const Elf64_Sym *sym) | |
94 | { | |
95 | return 0; | |
96 | } | |
d2fae548 RR |
97 | #endif |
98 | ||
1da177e4 LT |
99 | /* Like PPC32, we need little trampolines to do > 24-bit jumps (into |
100 | the kernel itself). But on PPC64, these need to be used for every | |
101 | jump, actually, to reset r2 (TOC+0x8000). */ | |
102 | struct ppc64_stub_entry | |
103 | { | |
83775b85 AB |
104 | /* 28 byte jump instruction sequence (7 instructions). We only |
105 | * need 6 instructions on ABIv2 but we always allocate 7 so | |
106 | * so we don't have to modify the trampoline load instruction. */ | |
0e60e46e RR |
107 | u32 jump[7]; |
108 | u32 unused; | |
1da177e4 | 109 | /* Data for the above code */ |
008d7a91 | 110 | func_desc_t funcdata; |
1da177e4 LT |
111 | }; |
112 | ||
5c729a11 RR |
113 | /* |
114 | * PPC64 uses 24 bit jumps, but we need to jump into other modules or | |
115 | * the kernel which may be further. So we jump to a stub. | |
116 | * | |
117 | * For ELFv1 we need to use this to set up the new r2 value (aka TOC | |
118 | * pointer). For ELFv2 it's the callee's responsibility to set up the | |
119 | * new r2, but for both we need to save the old r2. | |
120 | * | |
121 | * We could simply patch the new r2 value and function pointer into | |
122 | * the stub, but it's significantly shorter to put these values at the | |
123 | * end of the stub code, and patch the stub address (32-bits relative | |
124 | * to the TOC ptr, r2) into the stub. | |
125 | */ | |
83775b85 AB |
126 | |
127 | static u32 ppc64_stub_insns[] = { | |
b1ce369e RR |
128 | 0x3d620000, /* addis r11,r2, <high> */ |
129 | 0x396b0000, /* addi r11,r11, <low> */ | |
fed8393e | 130 | /* Save current r2 value in magic place on the stack. */ |
d2fae548 | 131 | 0xf8410000|R2_STACK_OFFSET, /* std r2,R2_STACK_OFFSET(r1) */ |
b1ce369e | 132 | 0xe98b0020, /* ld r12,32(r11) */ |
5c729a11 RR |
133 | #if !defined(_CALL_ELF) || _CALL_ELF != 2 |
134 | /* Set up new r2 from function descriptor */ | |
872aa779 | 135 | 0xe84b0028, /* ld r2,40(r11) */ |
5c729a11 | 136 | #endif |
b1ce369e | 137 | 0x7d8903a6, /* mtctr r12 */ |
d2fae548 | 138 | 0x4e800420 /* bctr */ |
83775b85 AB |
139 | }; |
140 | ||
141 | #ifdef CONFIG_DYNAMIC_FTRACE | |
142 | ||
143 | static u32 ppc64_stub_mask[] = { | |
144 | 0xffff0000, | |
145 | 0xffff0000, | |
146 | 0xffffffff, | |
147 | 0xffffffff, | |
148 | #if !defined(_CALL_ELF) || _CALL_ELF != 2 | |
149 | 0xffffffff, | |
150 | #endif | |
151 | 0xffffffff, | |
152 | 0xffffffff | |
153 | }; | |
154 | ||
155 | bool is_module_trampoline(u32 *p) | |
156 | { | |
157 | unsigned int i; | |
158 | u32 insns[ARRAY_SIZE(ppc64_stub_insns)]; | |
159 | ||
160 | BUILD_BUG_ON(sizeof(ppc64_stub_insns) != sizeof(ppc64_stub_mask)); | |
161 | ||
162 | if (probe_kernel_read(insns, p, sizeof(insns))) | |
163 | return -EFAULT; | |
164 | ||
165 | for (i = 0; i < ARRAY_SIZE(ppc64_stub_insns); i++) { | |
166 | u32 insna = insns[i]; | |
167 | u32 insnb = ppc64_stub_insns[i]; | |
168 | u32 mask = ppc64_stub_mask[i]; | |
169 | ||
170 | if ((insna & mask) != (insnb & mask)) | |
171 | return false; | |
172 | } | |
173 | ||
174 | return true; | |
175 | } | |
176 | ||
dd9fa162 AB |
177 | int module_trampoline_target(struct module *mod, u32 *trampoline, |
178 | unsigned long *target) | |
179 | { | |
180 | u32 buf[2]; | |
181 | u16 upper, lower; | |
182 | long offset; | |
183 | void *toc_entry; | |
184 | ||
185 | if (probe_kernel_read(buf, trampoline, sizeof(buf))) | |
186 | return -EFAULT; | |
187 | ||
188 | upper = buf[0] & 0xffff; | |
189 | lower = buf[1] & 0xffff; | |
190 | ||
191 | /* perform the addis/addi, both signed */ | |
192 | offset = ((short)upper << 16) + (short)lower; | |
193 | ||
194 | /* | |
195 | * Now get the address this trampoline jumps to. This | |
196 | * is always 32 bytes into our trampoline stub. | |
197 | */ | |
198 | toc_entry = (void *)mod->arch.toc + offset + 32; | |
199 | ||
200 | if (probe_kernel_read(target, toc_entry, sizeof(*target))) | |
201 | return -EFAULT; | |
202 | ||
203 | return 0; | |
204 | } | |
205 | ||
83775b85 | 206 | #endif |
1da177e4 LT |
207 | |
208 | /* Count how many different 24-bit relocations (different symbol, | |
209 | different addend) */ | |
210 | static unsigned int count_relocs(const Elf64_Rela *rela, unsigned int num) | |
211 | { | |
eda09fbd | 212 | unsigned int i, r_info, r_addend, _count_relocs; |
1da177e4 LT |
213 | |
214 | /* FIXME: Only count external ones --RR */ | |
eda09fbd EM |
215 | _count_relocs = 0; |
216 | r_info = 0; | |
217 | r_addend = 0; | |
218 | for (i = 0; i < num; i++) | |
1da177e4 | 219 | /* Only count 24-bit relocs, others don't need stubs */ |
eda09fbd EM |
220 | if (ELF64_R_TYPE(rela[i].r_info) == R_PPC_REL24 && |
221 | (r_info != ELF64_R_SYM(rela[i].r_info) || | |
222 | r_addend != rela[i].r_addend)) { | |
223 | _count_relocs++; | |
224 | r_info = ELF64_R_SYM(rela[i].r_info); | |
225 | r_addend = rela[i].r_addend; | |
1da177e4 | 226 | } |
eda09fbd EM |
227 | |
228 | return _count_relocs; | |
1da177e4 LT |
229 | } |
230 | ||
eda09fbd EM |
231 | static int relacmp(const void *_x, const void *_y) |
232 | { | |
233 | const Elf64_Rela *x, *y; | |
234 | ||
235 | y = (Elf64_Rela *)_x; | |
236 | x = (Elf64_Rela *)_y; | |
237 | ||
238 | /* Compare the entire r_info (as opposed to ELF64_R_SYM(r_info) only) to | |
239 | * make the comparison cheaper/faster. It won't affect the sorting or | |
240 | * the counting algorithms' performance | |
241 | */ | |
242 | if (x->r_info < y->r_info) | |
243 | return -1; | |
244 | else if (x->r_info > y->r_info) | |
245 | return 1; | |
246 | else if (x->r_addend < y->r_addend) | |
247 | return -1; | |
248 | else if (x->r_addend > y->r_addend) | |
249 | return 1; | |
250 | else | |
251 | return 0; | |
252 | } | |
253 | ||
254 | static void relaswap(void *_x, void *_y, int size) | |
255 | { | |
256 | uint64_t *x, *y, tmp; | |
257 | int i; | |
258 | ||
259 | y = (uint64_t *)_x; | |
260 | x = (uint64_t *)_y; | |
261 | ||
262 | for (i = 0; i < sizeof(Elf64_Rela) / sizeof(uint64_t); i++) { | |
263 | tmp = x[i]; | |
264 | x[i] = y[i]; | |
265 | y[i] = tmp; | |
266 | } | |
267 | } | |
268 | ||
1da177e4 LT |
269 | /* Get size of potential trampolines required. */ |
270 | static unsigned long get_stubs_size(const Elf64_Ehdr *hdr, | |
271 | const Elf64_Shdr *sechdrs) | |
272 | { | |
273 | /* One extra reloc so it's always 0-funcaddr terminated */ | |
274 | unsigned long relocs = 1; | |
275 | unsigned i; | |
276 | ||
277 | /* Every relocated section... */ | |
278 | for (i = 1; i < hdr->e_shnum; i++) { | |
279 | if (sechdrs[i].sh_type == SHT_RELA) { | |
c7d1f6af AB |
280 | pr_debug("Found relocations in section %u\n", i); |
281 | pr_debug("Ptr: %p. Number: %Lu\n", | |
1da177e4 LT |
282 | (void *)sechdrs[i].sh_addr, |
283 | sechdrs[i].sh_size / sizeof(Elf64_Rela)); | |
eda09fbd EM |
284 | |
285 | /* Sort the relocation information based on a symbol and | |
286 | * addend key. This is a stable O(n*log n) complexity | |
287 | * alogrithm but it will reduce the complexity of | |
288 | * count_relocs() to linear complexity O(n) | |
289 | */ | |
290 | sort((void *)sechdrs[i].sh_addr, | |
291 | sechdrs[i].sh_size / sizeof(Elf64_Rela), | |
292 | sizeof(Elf64_Rela), relacmp, relaswap); | |
293 | ||
1da177e4 LT |
294 | relocs += count_relocs((void *)sechdrs[i].sh_addr, |
295 | sechdrs[i].sh_size | |
296 | / sizeof(Elf64_Rela)); | |
297 | } | |
298 | } | |
299 | ||
f48cb8b4 SR |
300 | #ifdef CONFIG_DYNAMIC_FTRACE |
301 | /* make the trampoline to the ftrace_caller */ | |
302 | relocs++; | |
303 | #endif | |
304 | ||
c7d1f6af | 305 | pr_debug("Looks like a total of %lu stubs, max\n", relocs); |
1da177e4 LT |
306 | return relocs * sizeof(struct ppc64_stub_entry); |
307 | } | |
308 | ||
5b12c5c6 | 309 | /* Still needed for ELFv2, for .TOC. */ |
1da177e4 LT |
310 | static void dedotify_versions(struct modversion_info *vers, |
311 | unsigned long size) | |
312 | { | |
313 | struct modversion_info *end; | |
314 | ||
315 | for (end = (void *)vers + size; vers < end; vers++) | |
c2cbcf53 | 316 | if (vers->name[0] == '.') { |
1da177e4 | 317 | memmove(vers->name, vers->name+1, strlen(vers->name)); |
c2cbcf53 LD |
318 | #ifdef ARCH_RELOCATES_KCRCTAB |
319 | /* The TOC symbol has no CRC computed. To avoid CRC | |
320 | * check failing, we must force it to the expected | |
321 | * value (see CRC check in module.c). | |
322 | */ | |
323 | if (!strcmp(vers->name, "TOC.")) | |
324 | vers->crc = -(unsigned long)reloc_start; | |
325 | #endif | |
326 | } | |
1da177e4 LT |
327 | } |
328 | ||
c153693d AM |
329 | /* |
330 | * Undefined symbols which refer to .funcname, hack to funcname. Make .TOC. | |
331 | * seem to be defined (value set later). | |
332 | */ | |
1da177e4 LT |
333 | static void dedotify(Elf64_Sym *syms, unsigned int numsyms, char *strtab) |
334 | { | |
335 | unsigned int i; | |
336 | ||
337 | for (i = 1; i < numsyms; i++) { | |
338 | if (syms[i].st_shndx == SHN_UNDEF) { | |
339 | char *name = strtab + syms[i].st_name; | |
c153693d AM |
340 | if (name[0] == '.') { |
341 | if (strcmp(name+1, "TOC.") == 0) | |
342 | syms[i].st_shndx = SHN_ABS; | |
f15838e9 | 343 | syms[i].st_name++; |
c153693d | 344 | } |
1da177e4 LT |
345 | } |
346 | } | |
347 | } | |
348 | ||
4edebbea RR |
349 | static Elf64_Sym *find_dot_toc(Elf64_Shdr *sechdrs, |
350 | const char *strtab, | |
351 | unsigned int symindex) | |
352 | { | |
353 | unsigned int i, numsyms; | |
354 | Elf64_Sym *syms; | |
355 | ||
356 | syms = (Elf64_Sym *)sechdrs[symindex].sh_addr; | |
357 | numsyms = sechdrs[symindex].sh_size / sizeof(Elf64_Sym); | |
358 | ||
359 | for (i = 1; i < numsyms; i++) { | |
c153693d | 360 | if (syms[i].st_shndx == SHN_ABS |
008d7a91 | 361 | && strcmp(strtab + syms[i].st_name, "TOC.") == 0) |
4edebbea RR |
362 | return &syms[i]; |
363 | } | |
364 | return NULL; | |
365 | } | |
366 | ||
1da177e4 LT |
367 | int module_frob_arch_sections(Elf64_Ehdr *hdr, |
368 | Elf64_Shdr *sechdrs, | |
369 | char *secstrings, | |
370 | struct module *me) | |
371 | { | |
372 | unsigned int i; | |
373 | ||
374 | /* Find .toc and .stubs sections, symtab and strtab */ | |
375 | for (i = 1; i < hdr->e_shnum; i++) { | |
376 | char *p; | |
377 | if (strcmp(secstrings + sechdrs[i].sh_name, ".stubs") == 0) | |
378 | me->arch.stubs_section = i; | |
379 | else if (strcmp(secstrings + sechdrs[i].sh_name, ".toc") == 0) | |
380 | me->arch.toc_section = i; | |
381 | else if (strcmp(secstrings+sechdrs[i].sh_name,"__versions")==0) | |
382 | dedotify_versions((void *)hdr + sechdrs[i].sh_offset, | |
383 | sechdrs[i].sh_size); | |
384 | ||
385 | /* We don't handle .init for the moment: rename to _init */ | |
386 | while ((p = strstr(secstrings + sechdrs[i].sh_name, ".init"))) | |
387 | p[0] = '_'; | |
388 | ||
389 | if (sechdrs[i].sh_type == SHT_SYMTAB) | |
390 | dedotify((void *)hdr + sechdrs[i].sh_offset, | |
391 | sechdrs[i].sh_size / sizeof(Elf64_Sym), | |
392 | (void *)hdr | |
393 | + sechdrs[sechdrs[i].sh_link].sh_offset); | |
394 | } | |
f749edae AM |
395 | |
396 | if (!me->arch.stubs_section) { | |
c7d1f6af | 397 | pr_err("%s: doesn't contain .stubs.\n", me->name); |
1da177e4 LT |
398 | return -ENOEXEC; |
399 | } | |
400 | ||
f749edae AM |
401 | /* If we don't have a .toc, just use .stubs. We need to set r2 |
402 | to some reasonable value in case the module calls out to | |
403 | other functions via a stub, or if a function pointer escapes | |
404 | the module by some means. */ | |
405 | if (!me->arch.toc_section) | |
406 | me->arch.toc_section = me->arch.stubs_section; | |
407 | ||
1da177e4 LT |
408 | /* Override the stubs size */ |
409 | sechdrs[me->arch.stubs_section].sh_size = get_stubs_size(hdr, sechdrs); | |
410 | return 0; | |
411 | } | |
412 | ||
1da177e4 LT |
413 | /* r2 is the TOC pointer: it actually points 0x8000 into the TOC (this |
414 | gives the value maximum span in an instruction which uses a signed | |
415 | offset) */ | |
416 | static inline unsigned long my_r2(Elf64_Shdr *sechdrs, struct module *me) | |
417 | { | |
418 | return sechdrs[me->arch.toc_section].sh_addr + 0x8000; | |
419 | } | |
420 | ||
421 | /* Both low and high 16 bits are added as SIGNED additions, so if low | |
422 | 16 bits has high bit set, high 16 bits must be adjusted. These | |
423 | macros do that (stolen from binutils). */ | |
424 | #define PPC_LO(v) ((v) & 0xffff) | |
425 | #define PPC_HI(v) (((v) >> 16) & 0xffff) | |
426 | #define PPC_HA(v) PPC_HI ((v) + 0x8000) | |
427 | ||
428 | /* Patch stub to reference function and correct r2 value. */ | |
429 | static inline int create_stub(Elf64_Shdr *sechdrs, | |
430 | struct ppc64_stub_entry *entry, | |
008d7a91 | 431 | unsigned long addr, |
1da177e4 LT |
432 | struct module *me) |
433 | { | |
1da177e4 LT |
434 | long reladdr; |
435 | ||
83775b85 | 436 | memcpy(entry->jump, ppc64_stub_insns, sizeof(ppc64_stub_insns)); |
1da177e4 | 437 | |
1da177e4 LT |
438 | /* Stub uses address relative to r2. */ |
439 | reladdr = (unsigned long)entry - my_r2(sechdrs, me); | |
440 | if (reladdr > 0x7FFFFFFF || reladdr < -(0x80000000L)) { | |
c7d1f6af | 441 | pr_err("%s: Address %p of stub out of range of %p.\n", |
1da177e4 LT |
442 | me->name, (void *)reladdr, (void *)my_r2); |
443 | return 0; | |
444 | } | |
c7d1f6af | 445 | pr_debug("Stub %p get data from reladdr %li\n", entry, reladdr); |
1da177e4 | 446 | |
0e60e46e RR |
447 | entry->jump[0] |= PPC_HA(reladdr); |
448 | entry->jump[1] |= PPC_LO(reladdr); | |
008d7a91 | 449 | entry->funcdata = func_desc(addr); |
1da177e4 LT |
450 | return 1; |
451 | } | |
452 | ||
008d7a91 | 453 | /* Create stub to jump to function described in this OPD/ptr: we need the |
1da177e4 LT |
454 | stub to set up the TOC ptr (r2) for the function. */ |
455 | static unsigned long stub_for_addr(Elf64_Shdr *sechdrs, | |
008d7a91 | 456 | unsigned long addr, |
1da177e4 LT |
457 | struct module *me) |
458 | { | |
459 | struct ppc64_stub_entry *stubs; | |
1da177e4 LT |
460 | unsigned int i, num_stubs; |
461 | ||
462 | num_stubs = sechdrs[me->arch.stubs_section].sh_size / sizeof(*stubs); | |
463 | ||
464 | /* Find this stub, or if that fails, the next avail. entry */ | |
465 | stubs = (void *)sechdrs[me->arch.stubs_section].sh_addr; | |
008d7a91 | 466 | for (i = 0; stub_func_addr(stubs[i].funcdata); i++) { |
1da177e4 LT |
467 | BUG_ON(i >= num_stubs); |
468 | ||
008d7a91 | 469 | if (stub_func_addr(stubs[i].funcdata) == func_addr(addr)) |
1da177e4 LT |
470 | return (unsigned long)&stubs[i]; |
471 | } | |
472 | ||
008d7a91 | 473 | if (!create_stub(sechdrs, &stubs[i], addr, me)) |
1da177e4 LT |
474 | return 0; |
475 | ||
476 | return (unsigned long)&stubs[i]; | |
477 | } | |
478 | ||
479 | /* We expect a noop next: if it is, replace it with instruction to | |
480 | restore r2. */ | |
481 | static int restore_r2(u32 *instruction, struct module *me) | |
482 | { | |
16c57b36 | 483 | if (*instruction != PPC_INST_NOP) { |
c7d1f6af | 484 | pr_err("%s: Expect noop after relocate, got %08x\n", |
1da177e4 LT |
485 | me->name, *instruction); |
486 | return 0; | |
487 | } | |
d2fae548 RR |
488 | /* ld r2,R2_STACK_OFFSET(r1) */ |
489 | *instruction = 0xe8410000 | R2_STACK_OFFSET; | |
1da177e4 LT |
490 | return 1; |
491 | } | |
492 | ||
493 | int apply_relocate_add(Elf64_Shdr *sechdrs, | |
494 | const char *strtab, | |
495 | unsigned int symindex, | |
496 | unsigned int relsec, | |
497 | struct module *me) | |
498 | { | |
499 | unsigned int i; | |
500 | Elf64_Rela *rela = (void *)sechdrs[relsec].sh_addr; | |
501 | Elf64_Sym *sym; | |
502 | unsigned long *location; | |
503 | unsigned long value; | |
504 | ||
c7d1f6af | 505 | pr_debug("Applying ADD relocate section %u to %u\n", relsec, |
1da177e4 | 506 | sechdrs[relsec].sh_info); |
4edebbea RR |
507 | |
508 | /* First time we're called, we can fix up .TOC. */ | |
509 | if (!me->arch.toc_fixed) { | |
510 | sym = find_dot_toc(sechdrs, strtab, symindex); | |
511 | /* It's theoretically possible that a module doesn't want a | |
512 | * .TOC. so don't fail it just for that. */ | |
513 | if (sym) | |
514 | sym->st_value = my_r2(sechdrs, me); | |
515 | me->arch.toc_fixed = true; | |
516 | } | |
517 | ||
1da177e4 LT |
518 | for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) { |
519 | /* This is where to make the change */ | |
520 | location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr | |
521 | + rela[i].r_offset; | |
522 | /* This is the symbol it is referring to */ | |
523 | sym = (Elf64_Sym *)sechdrs[symindex].sh_addr | |
524 | + ELF64_R_SYM(rela[i].r_info); | |
525 | ||
c7d1f6af | 526 | pr_debug("RELOC at %p: %li-type as %s (0x%lx) + %li\n", |
1da177e4 LT |
527 | location, (long)ELF64_R_TYPE(rela[i].r_info), |
528 | strtab + sym->st_name, (unsigned long)sym->st_value, | |
529 | (long)rela[i].r_addend); | |
530 | ||
531 | /* `Everything is relative'. */ | |
532 | value = sym->st_value + rela[i].r_addend; | |
533 | ||
534 | switch (ELF64_R_TYPE(rela[i].r_info)) { | |
535 | case R_PPC64_ADDR32: | |
536 | /* Simply set it */ | |
537 | *(u32 *)location = value; | |
538 | break; | |
eda09fbd | 539 | |
1da177e4 LT |
540 | case R_PPC64_ADDR64: |
541 | /* Simply set it */ | |
542 | *(unsigned long *)location = value; | |
543 | break; | |
544 | ||
545 | case R_PPC64_TOC: | |
546 | *(unsigned long *)location = my_r2(sechdrs, me); | |
547 | break; | |
548 | ||
9149ccfa | 549 | case R_PPC64_TOC16: |
f749edae | 550 | /* Subtract TOC pointer */ |
9149ccfa PB |
551 | value -= my_r2(sechdrs, me); |
552 | if (value + 0x8000 > 0xffff) { | |
c7d1f6af | 553 | pr_err("%s: bad TOC16 relocation (0x%lx)\n", |
9149ccfa PB |
554 | me->name, value); |
555 | return -ENOEXEC; | |
556 | } | |
557 | *((uint16_t *) location) | |
558 | = (*((uint16_t *) location) & ~0xffff) | |
559 | | (value & 0xffff); | |
560 | break; | |
561 | ||
1fbe9cf2 AB |
562 | case R_PPC64_TOC16_LO: |
563 | /* Subtract TOC pointer */ | |
564 | value -= my_r2(sechdrs, me); | |
565 | *((uint16_t *) location) | |
566 | = (*((uint16_t *) location) & ~0xffff) | |
567 | | (value & 0xffff); | |
568 | break; | |
569 | ||
1da177e4 | 570 | case R_PPC64_TOC16_DS: |
f749edae | 571 | /* Subtract TOC pointer */ |
1da177e4 LT |
572 | value -= my_r2(sechdrs, me); |
573 | if ((value & 3) != 0 || value + 0x8000 > 0xffff) { | |
c7d1f6af | 574 | pr_err("%s: bad TOC16_DS relocation (0x%lx)\n", |
1da177e4 LT |
575 | me->name, value); |
576 | return -ENOEXEC; | |
577 | } | |
578 | *((uint16_t *) location) | |
579 | = (*((uint16_t *) location) & ~0xfffc) | |
580 | | (value & 0xfffc); | |
581 | break; | |
582 | ||
1fbe9cf2 AB |
583 | case R_PPC64_TOC16_LO_DS: |
584 | /* Subtract TOC pointer */ | |
585 | value -= my_r2(sechdrs, me); | |
586 | if ((value & 3) != 0) { | |
c7d1f6af | 587 | pr_err("%s: bad TOC16_LO_DS relocation (0x%lx)\n", |
1fbe9cf2 AB |
588 | me->name, value); |
589 | return -ENOEXEC; | |
590 | } | |
591 | *((uint16_t *) location) | |
592 | = (*((uint16_t *) location) & ~0xfffc) | |
593 | | (value & 0xfffc); | |
594 | break; | |
595 | ||
596 | case R_PPC64_TOC16_HA: | |
597 | /* Subtract TOC pointer */ | |
598 | value -= my_r2(sechdrs, me); | |
599 | value = ((value + 0x8000) >> 16); | |
600 | *((uint16_t *) location) | |
601 | = (*((uint16_t *) location) & ~0xffff) | |
602 | | (value & 0xffff); | |
603 | break; | |
604 | ||
1da177e4 LT |
605 | case R_PPC_REL24: |
606 | /* FIXME: Handle weak symbols here --RR */ | |
607 | if (sym->st_shndx == SHN_UNDEF) { | |
608 | /* External: go via stub */ | |
609 | value = stub_for_addr(sechdrs, value, me); | |
610 | if (!value) | |
611 | return -ENOENT; | |
612 | if (!restore_r2((u32 *)location + 1, me)) | |
613 | return -ENOEXEC; | |
008d7a91 RR |
614 | } else |
615 | value += local_entry_offset(sym); | |
1da177e4 LT |
616 | |
617 | /* Convert value to relative */ | |
618 | value -= (unsigned long)location; | |
619 | if (value + 0x2000000 > 0x3ffffff || (value & 3) != 0){ | |
c7d1f6af | 620 | pr_err("%s: REL24 %li out of range!\n", |
1da177e4 LT |
621 | me->name, (long int)value); |
622 | return -ENOEXEC; | |
623 | } | |
624 | ||
625 | /* Only replace bits 2 through 26 */ | |
eda09fbd | 626 | *(uint32_t *)location |
1da177e4 LT |
627 | = (*(uint32_t *)location & ~0x03fffffc) |
628 | | (value & 0x03fffffc); | |
629 | break; | |
630 | ||
21c4ff80 BH |
631 | case R_PPC64_REL64: |
632 | /* 64 bits relative (used by features fixups) */ | |
633 | *location = value - (unsigned long)location; | |
634 | break; | |
635 | ||
d247da0a RR |
636 | case R_PPC64_TOCSAVE: |
637 | /* | |
638 | * Marker reloc indicates we don't have to save r2. | |
639 | * That would only save us one instruction, so ignore | |
640 | * it. | |
641 | */ | |
642 | break; | |
643 | ||
a61674bd UW |
644 | case R_PPC64_ENTRY: |
645 | /* | |
646 | * Optimize ELFv2 large code model entry point if | |
647 | * the TOC is within 2GB range of current location. | |
648 | */ | |
649 | value = my_r2(sechdrs, me) - (unsigned long)location; | |
650 | if (value + 0x80008000 > 0xffffffff) | |
651 | break; | |
652 | /* | |
653 | * Check for the large code model prolog sequence: | |
654 | * ld r2, ...(r12) | |
655 | * add r2, r2, r12 | |
656 | */ | |
657 | if ((((uint32_t *)location)[0] & ~0xfffc) | |
658 | != 0xe84c0000) | |
659 | break; | |
660 | if (((uint32_t *)location)[1] != 0x7c426214) | |
661 | break; | |
662 | /* | |
663 | * If found, replace it with: | |
664 | * addis r2, r12, (.TOC.-func)@ha | |
665 | * addi r2, r12, (.TOC.-func)@l | |
666 | */ | |
667 | ((uint32_t *)location)[0] = 0x3c4c0000 + PPC_HA(value); | |
668 | ((uint32_t *)location)[1] = 0x38420000 + PPC_LO(value); | |
669 | break; | |
670 | ||
0906584a RR |
671 | case R_PPC64_REL16_HA: |
672 | /* Subtract location pointer */ | |
673 | value -= (unsigned long)location; | |
674 | value = ((value + 0x8000) >> 16); | |
675 | *((uint16_t *) location) | |
676 | = (*((uint16_t *) location) & ~0xffff) | |
677 | | (value & 0xffff); | |
678 | break; | |
679 | ||
680 | case R_PPC64_REL16_LO: | |
681 | /* Subtract location pointer */ | |
682 | value -= (unsigned long)location; | |
683 | *((uint16_t *) location) | |
684 | = (*((uint16_t *) location) & ~0xffff) | |
685 | | (value & 0xffff); | |
686 | break; | |
687 | ||
1da177e4 | 688 | default: |
c7d1f6af | 689 | pr_err("%s: Unknown ADD relocation: %lu\n", |
1da177e4 LT |
690 | me->name, |
691 | (unsigned long)ELF64_R_TYPE(rela[i].r_info)); | |
692 | return -ENOEXEC; | |
693 | } | |
694 | } | |
695 | ||
f48cb8b4 SR |
696 | #ifdef CONFIG_DYNAMIC_FTRACE |
697 | me->arch.toc = my_r2(sechdrs, me); | |
698 | me->arch.tramp = stub_for_addr(sechdrs, | |
699 | (unsigned long)ftrace_caller, | |
700 | me); | |
701 | #endif | |
702 | ||
1da177e4 LT |
703 | return 0; |
704 | } |