1 /* 2 * Copyright 2008 Michael Ellerman, IBM Corporation. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 7 * 2 of the License, or (at your option) any later version. 8 */ 9 10 #include <linux/kernel.h> 11 #include <linux/kprobes.h> 12 #include <linux/vmalloc.h> 13 #include <linux/init.h> 14 #include <linux/mm.h> 15 #include <linux/cpuhotplug.h> 16 #include <linux/slab.h> 17 #include <linux/uaccess.h> 18 #include <linux/kprobes.h> 19 20 #include <asm/pgtable.h> 21 #include <asm/tlbflush.h> 22 #include <asm/page.h> 23 #include <asm/code-patching.h> 24 #include <asm/setup.h> 25 26 static int __patch_instruction(unsigned int *exec_addr, unsigned int instr, 27 unsigned int *patch_addr) 28 { 29 int err; 30 31 __put_user_size(instr, patch_addr, 4, err); 32 if (err) 33 return err; 34 35 asm ("dcbst 0, %0; sync; icbi 0,%1; sync; isync" :: "r" (patch_addr), 36 "r" (exec_addr)); 37 38 return 0; 39 } 40 41 int raw_patch_instruction(unsigned int *addr, unsigned int instr) 42 { 43 return __patch_instruction(addr, instr, addr); 44 } 45 46 #ifdef CONFIG_STRICT_KERNEL_RWX 47 static DEFINE_PER_CPU(struct vm_struct *, text_poke_area); 48 49 static int text_area_cpu_up(unsigned int cpu) 50 { 51 struct vm_struct *area; 52 53 area = get_vm_area(PAGE_SIZE, VM_ALLOC); 54 if (!area) { 55 WARN_ONCE(1, "Failed to create text area for cpu %d\n", 56 cpu); 57 return -1; 58 } 59 this_cpu_write(text_poke_area, area); 60 61 return 0; 62 } 63 64 static int text_area_cpu_down(unsigned int cpu) 65 { 66 free_vm_area(this_cpu_read(text_poke_area)); 67 return 0; 68 } 69 70 /* 71 * Run as a late init call. This allows all the boot time patching to be done 72 * simply by patching the code, and then we're called here prior to 73 * mark_rodata_ro(), which happens after all init calls are run. Although 74 * BUG_ON() is rude, in this case it should only happen if ENOMEM, and we judge 75 * it as being preferable to a kernel that will crash later when someone tries 76 * to use patch_instruction(). 77 */ 78 static int __init setup_text_poke_area(void) 79 { 80 BUG_ON(!cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, 81 "powerpc/text_poke:online", text_area_cpu_up, 82 text_area_cpu_down)); 83 84 return 0; 85 } 86 late_initcall(setup_text_poke_area); 87 88 /* 89 * This can be called for kernel text or a module. 90 */ 91 static int map_patch_area(void *addr, unsigned long text_poke_addr) 92 { 93 unsigned long pfn; 94 int err; 95 96 if (is_vmalloc_addr(addr)) 97 pfn = vmalloc_to_pfn(addr); 98 else 99 pfn = __pa_symbol(addr) >> PAGE_SHIFT; 100 101 err = map_kernel_page(text_poke_addr, (pfn << PAGE_SHIFT), 102 pgprot_val(PAGE_KERNEL)); 103 104 pr_devel("Mapped addr %lx with pfn %lx:%d\n", text_poke_addr, pfn, err); 105 if (err) 106 return -1; 107 108 return 0; 109 } 110 111 static inline int unmap_patch_area(unsigned long addr) 112 { 113 pte_t *ptep; 114 pmd_t *pmdp; 115 pud_t *pudp; 116 pgd_t *pgdp; 117 118 pgdp = pgd_offset_k(addr); 119 if (unlikely(!pgdp)) 120 return -EINVAL; 121 122 pudp = pud_offset(pgdp, addr); 123 if (unlikely(!pudp)) 124 return -EINVAL; 125 126 pmdp = pmd_offset(pudp, addr); 127 if (unlikely(!pmdp)) 128 return -EINVAL; 129 130 ptep = pte_offset_kernel(pmdp, addr); 131 if (unlikely(!ptep)) 132 return -EINVAL; 133 134 pr_devel("clearing mm %p, pte %p, addr %lx\n", &init_mm, ptep, addr); 135 136 /* 137 * In hash, pte_clear flushes the tlb, in radix, we have to 138 */ 139 pte_clear(&init_mm, addr, ptep); 140 flush_tlb_kernel_range(addr, addr + PAGE_SIZE); 141 142 return 0; 143 } 144 145 int patch_instruction(unsigned int *addr, unsigned int instr) 146 { 147 int err; 148 unsigned int *patch_addr = NULL; 149 unsigned long flags; 150 unsigned long text_poke_addr; 151 unsigned long kaddr = (unsigned long)addr; 152 153 /* 154 * During early early boot patch_instruction is called 155 * when text_poke_area is not ready, but we still need 156 * to allow patching. We just do the plain old patching 157 */ 158 if (!this_cpu_read(text_poke_area)) 159 return raw_patch_instruction(addr, instr); 160 161 local_irq_save(flags); 162 163 text_poke_addr = (unsigned long)__this_cpu_read(text_poke_area)->addr; 164 if (map_patch_area(addr, text_poke_addr)) { 165 err = -1; 166 goto out; 167 } 168 169 patch_addr = (unsigned int *)(text_poke_addr) + 170 ((kaddr & ~PAGE_MASK) / sizeof(unsigned int)); 171 172 __patch_instruction(addr, instr, patch_addr); 173 174 err = unmap_patch_area(text_poke_addr); 175 if (err) 176 pr_warn("failed to unmap %lx\n", text_poke_addr); 177 178 out: 179 local_irq_restore(flags); 180 181 return err; 182 } 183 #else /* !CONFIG_STRICT_KERNEL_RWX */ 184 185 int patch_instruction(unsigned int *addr, unsigned int instr) 186 { 187 return raw_patch_instruction(addr, instr); 188 } 189 190 #endif /* CONFIG_STRICT_KERNEL_RWX */ 191 NOKPROBE_SYMBOL(patch_instruction); 192 193 int patch_branch(unsigned int *addr, unsigned long target, int flags) 194 { 195 return patch_instruction(addr, create_branch(addr, target, flags)); 196 } 197 198 int patch_branch_site(s32 *site, unsigned long target, int flags) 199 { 200 unsigned int *addr; 201 202 addr = (unsigned int *)((unsigned long)site + *site); 203 return patch_instruction(addr, create_branch(addr, target, flags)); 204 } 205 206 int patch_instruction_site(s32 *site, unsigned int instr) 207 { 208 unsigned int *addr; 209 210 addr = (unsigned int *)((unsigned long)site + *site); 211 return patch_instruction(addr, instr); 212 } 213 214 bool is_offset_in_branch_range(long offset) 215 { 216 /* 217 * Powerpc branch instruction is : 218 * 219 * 0 6 30 31 220 * +---------+----------------+---+---+ 221 * | opcode | LI |AA |LK | 222 * +---------+----------------+---+---+ 223 * Where AA = 0 and LK = 0 224 * 225 * LI is a signed 24 bits integer. The real branch offset is computed 226 * by: imm32 = SignExtend(LI:'0b00', 32); 227 * 228 * So the maximum forward branch should be: 229 * (0x007fffff << 2) = 0x01fffffc = 0x1fffffc 230 * The maximum backward branch should be: 231 * (0xff800000 << 2) = 0xfe000000 = -0x2000000 232 */ 233 return (offset >= -0x2000000 && offset <= 0x1fffffc && !(offset & 0x3)); 234 } 235 236 /* 237 * Helper to check if a given instruction is a conditional branch 238 * Derived from the conditional checks in analyse_instr() 239 */ 240 bool is_conditional_branch(unsigned int instr) 241 { 242 unsigned int opcode = instr >> 26; 243 244 if (opcode == 16) /* bc, bca, bcl, bcla */ 245 return true; 246 if (opcode == 19) { 247 switch ((instr >> 1) & 0x3ff) { 248 case 16: /* bclr, bclrl */ 249 case 528: /* bcctr, bcctrl */ 250 case 560: /* bctar, bctarl */ 251 return true; 252 } 253 } 254 return false; 255 } 256 NOKPROBE_SYMBOL(is_conditional_branch); 257 258 unsigned int create_branch(const unsigned int *addr, 259 unsigned long target, int flags) 260 { 261 unsigned int instruction; 262 long offset; 263 264 offset = target; 265 if (! (flags & BRANCH_ABSOLUTE)) 266 offset = offset - (unsigned long)addr; 267 268 /* Check we can represent the target in the instruction format */ 269 if (!is_offset_in_branch_range(offset)) 270 return 0; 271 272 /* Mask out the flags and target, so they don't step on each other. */ 273 instruction = 0x48000000 | (flags & 0x3) | (offset & 0x03FFFFFC); 274 275 return instruction; 276 } 277 278 unsigned int create_cond_branch(const unsigned int *addr, 279 unsigned long target, int flags) 280 { 281 unsigned int instruction; 282 long offset; 283 284 offset = target; 285 if (! (flags & BRANCH_ABSOLUTE)) 286 offset = offset - (unsigned long)addr; 287 288 /* Check we can represent the target in the instruction format */ 289 if (offset < -0x8000 || offset > 0x7FFF || offset & 0x3) 290 return 0; 291 292 /* Mask out the flags and target, so they don't step on each other. */ 293 instruction = 0x40000000 | (flags & 0x3FF0003) | (offset & 0xFFFC); 294 295 return instruction; 296 } 297 298 static unsigned int branch_opcode(unsigned int instr) 299 { 300 return (instr >> 26) & 0x3F; 301 } 302 303 static int instr_is_branch_iform(unsigned int instr) 304 { 305 return branch_opcode(instr) == 18; 306 } 307 308 static int instr_is_branch_bform(unsigned int instr) 309 { 310 return branch_opcode(instr) == 16; 311 } 312 313 int instr_is_relative_branch(unsigned int instr) 314 { 315 if (instr & BRANCH_ABSOLUTE) 316 return 0; 317 318 return instr_is_branch_iform(instr) || instr_is_branch_bform(instr); 319 } 320 321 int instr_is_relative_link_branch(unsigned int instr) 322 { 323 return instr_is_relative_branch(instr) && (instr & BRANCH_SET_LINK); 324 } 325 326 static unsigned long branch_iform_target(const unsigned int *instr) 327 { 328 signed long imm; 329 330 imm = *instr & 0x3FFFFFC; 331 332 /* If the top bit of the immediate value is set this is negative */ 333 if (imm & 0x2000000) 334 imm -= 0x4000000; 335 336 if ((*instr & BRANCH_ABSOLUTE) == 0) 337 imm += (unsigned long)instr; 338 339 return (unsigned long)imm; 340 } 341 342 static unsigned long branch_bform_target(const unsigned int *instr) 343 { 344 signed long imm; 345 346 imm = *instr & 0xFFFC; 347 348 /* If the top bit of the immediate value is set this is negative */ 349 if (imm & 0x8000) 350 imm -= 0x10000; 351 352 if ((*instr & BRANCH_ABSOLUTE) == 0) 353 imm += (unsigned long)instr; 354 355 return (unsigned long)imm; 356 } 357 358 unsigned long branch_target(const unsigned int *instr) 359 { 360 if (instr_is_branch_iform(*instr)) 361 return branch_iform_target(instr); 362 else if (instr_is_branch_bform(*instr)) 363 return branch_bform_target(instr); 364 365 return 0; 366 } 367 368 int instr_is_branch_to_addr(const unsigned int *instr, unsigned long addr) 369 { 370 if (instr_is_branch_iform(*instr) || instr_is_branch_bform(*instr)) 371 return branch_target(instr) == addr; 372 373 return 0; 374 } 375 376 unsigned int translate_branch(const unsigned int *dest, const unsigned int *src) 377 { 378 unsigned long target; 379 380 target = branch_target(src); 381 382 if (instr_is_branch_iform(*src)) 383 return create_branch(dest, target, *src); 384 else if (instr_is_branch_bform(*src)) 385 return create_cond_branch(dest, target, *src); 386 387 return 0; 388 } 389 390 #ifdef CONFIG_PPC_BOOK3E_64 391 void __patch_exception(int exc, unsigned long addr) 392 { 393 extern unsigned int interrupt_base_book3e; 394 unsigned int *ibase = &interrupt_base_book3e; 395 396 /* Our exceptions vectors start with a NOP and -then- a branch 397 * to deal with single stepping from userspace which stops on 398 * the second instruction. Thus we need to patch the second 399 * instruction of the exception, not the first one 400 */ 401 402 patch_branch(ibase + (exc / 4) + 1, addr, 0); 403 } 404 #endif 405 406 #ifdef CONFIG_CODE_PATCHING_SELFTEST 407 408 static void __init test_trampoline(void) 409 { 410 asm ("nop;\n"); 411 } 412 413 #define check(x) \ 414 if (!(x)) printk("code-patching: test failed at line %d\n", __LINE__); 415 416 static void __init test_branch_iform(void) 417 { 418 unsigned int instr; 419 unsigned long addr; 420 421 addr = (unsigned long)&instr; 422 423 /* The simplest case, branch to self, no flags */ 424 check(instr_is_branch_iform(0x48000000)); 425 /* All bits of target set, and flags */ 426 check(instr_is_branch_iform(0x4bffffff)); 427 /* High bit of opcode set, which is wrong */ 428 check(!instr_is_branch_iform(0xcbffffff)); 429 /* Middle bits of opcode set, which is wrong */ 430 check(!instr_is_branch_iform(0x7bffffff)); 431 432 /* Simplest case, branch to self with link */ 433 check(instr_is_branch_iform(0x48000001)); 434 /* All bits of targets set */ 435 check(instr_is_branch_iform(0x4bfffffd)); 436 /* Some bits of targets set */ 437 check(instr_is_branch_iform(0x4bff00fd)); 438 /* Must be a valid branch to start with */ 439 check(!instr_is_branch_iform(0x7bfffffd)); 440 441 /* Absolute branch to 0x100 */ 442 instr = 0x48000103; 443 check(instr_is_branch_to_addr(&instr, 0x100)); 444 /* Absolute branch to 0x420fc */ 445 instr = 0x480420ff; 446 check(instr_is_branch_to_addr(&instr, 0x420fc)); 447 /* Maximum positive relative branch, + 20MB - 4B */ 448 instr = 0x49fffffc; 449 check(instr_is_branch_to_addr(&instr, addr + 0x1FFFFFC)); 450 /* Smallest negative relative branch, - 4B */ 451 instr = 0x4bfffffc; 452 check(instr_is_branch_to_addr(&instr, addr - 4)); 453 /* Largest negative relative branch, - 32 MB */ 454 instr = 0x4a000000; 455 check(instr_is_branch_to_addr(&instr, addr - 0x2000000)); 456 457 /* Branch to self, with link */ 458 instr = create_branch(&instr, addr, BRANCH_SET_LINK); 459 check(instr_is_branch_to_addr(&instr, addr)); 460 461 /* Branch to self - 0x100, with link */ 462 instr = create_branch(&instr, addr - 0x100, BRANCH_SET_LINK); 463 check(instr_is_branch_to_addr(&instr, addr - 0x100)); 464 465 /* Branch to self + 0x100, no link */ 466 instr = create_branch(&instr, addr + 0x100, 0); 467 check(instr_is_branch_to_addr(&instr, addr + 0x100)); 468 469 /* Maximum relative negative offset, - 32 MB */ 470 instr = create_branch(&instr, addr - 0x2000000, BRANCH_SET_LINK); 471 check(instr_is_branch_to_addr(&instr, addr - 0x2000000)); 472 473 /* Out of range relative negative offset, - 32 MB + 4*/ 474 instr = create_branch(&instr, addr - 0x2000004, BRANCH_SET_LINK); 475 check(instr == 0); 476 477 /* Out of range relative positive offset, + 32 MB */ 478 instr = create_branch(&instr, addr + 0x2000000, BRANCH_SET_LINK); 479 check(instr == 0); 480 481 /* Unaligned target */ 482 instr = create_branch(&instr, addr + 3, BRANCH_SET_LINK); 483 check(instr == 0); 484 485 /* Check flags are masked correctly */ 486 instr = create_branch(&instr, addr, 0xFFFFFFFC); 487 check(instr_is_branch_to_addr(&instr, addr)); 488 check(instr == 0x48000000); 489 } 490 491 static void __init test_create_function_call(void) 492 { 493 unsigned int *iptr; 494 unsigned long dest; 495 496 /* Check we can create a function call */ 497 iptr = (unsigned int *)ppc_function_entry(test_trampoline); 498 dest = ppc_function_entry(test_create_function_call); 499 patch_instruction(iptr, create_branch(iptr, dest, BRANCH_SET_LINK)); 500 check(instr_is_branch_to_addr(iptr, dest)); 501 } 502 503 static void __init test_branch_bform(void) 504 { 505 unsigned long addr; 506 unsigned int *iptr, instr, flags; 507 508 iptr = &instr; 509 addr = (unsigned long)iptr; 510 511 /* The simplest case, branch to self, no flags */ 512 check(instr_is_branch_bform(0x40000000)); 513 /* All bits of target set, and flags */ 514 check(instr_is_branch_bform(0x43ffffff)); 515 /* High bit of opcode set, which is wrong */ 516 check(!instr_is_branch_bform(0xc3ffffff)); 517 /* Middle bits of opcode set, which is wrong */ 518 check(!instr_is_branch_bform(0x7bffffff)); 519 520 /* Absolute conditional branch to 0x100 */ 521 instr = 0x43ff0103; 522 check(instr_is_branch_to_addr(&instr, 0x100)); 523 /* Absolute conditional branch to 0x20fc */ 524 instr = 0x43ff20ff; 525 check(instr_is_branch_to_addr(&instr, 0x20fc)); 526 /* Maximum positive relative conditional branch, + 32 KB - 4B */ 527 instr = 0x43ff7ffc; 528 check(instr_is_branch_to_addr(&instr, addr + 0x7FFC)); 529 /* Smallest negative relative conditional branch, - 4B */ 530 instr = 0x43fffffc; 531 check(instr_is_branch_to_addr(&instr, addr - 4)); 532 /* Largest negative relative conditional branch, - 32 KB */ 533 instr = 0x43ff8000; 534 check(instr_is_branch_to_addr(&instr, addr - 0x8000)); 535 536 /* All condition code bits set & link */ 537 flags = 0x3ff000 | BRANCH_SET_LINK; 538 539 /* Branch to self */ 540 instr = create_cond_branch(iptr, addr, flags); 541 check(instr_is_branch_to_addr(&instr, addr)); 542 543 /* Branch to self - 0x100 */ 544 instr = create_cond_branch(iptr, addr - 0x100, flags); 545 check(instr_is_branch_to_addr(&instr, addr - 0x100)); 546 547 /* Branch to self + 0x100 */ 548 instr = create_cond_branch(iptr, addr + 0x100, flags); 549 check(instr_is_branch_to_addr(&instr, addr + 0x100)); 550 551 /* Maximum relative negative offset, - 32 KB */ 552 instr = create_cond_branch(iptr, addr - 0x8000, flags); 553 check(instr_is_branch_to_addr(&instr, addr - 0x8000)); 554 555 /* Out of range relative negative offset, - 32 KB + 4*/ 556 instr = create_cond_branch(iptr, addr - 0x8004, flags); 557 check(instr == 0); 558 559 /* Out of range relative positive offset, + 32 KB */ 560 instr = create_cond_branch(iptr, addr + 0x8000, flags); 561 check(instr == 0); 562 563 /* Unaligned target */ 564 instr = create_cond_branch(iptr, addr + 3, flags); 565 check(instr == 0); 566 567 /* Check flags are masked correctly */ 568 instr = create_cond_branch(iptr, addr, 0xFFFFFFFC); 569 check(instr_is_branch_to_addr(&instr, addr)); 570 check(instr == 0x43FF0000); 571 } 572 573 static void __init test_translate_branch(void) 574 { 575 unsigned long addr; 576 unsigned int *p, *q; 577 void *buf; 578 579 buf = vmalloc(PAGE_ALIGN(0x2000000 + 1)); 580 check(buf); 581 if (!buf) 582 return; 583 584 /* Simple case, branch to self moved a little */ 585 p = buf; 586 addr = (unsigned long)p; 587 patch_branch(p, addr, 0); 588 check(instr_is_branch_to_addr(p, addr)); 589 q = p + 1; 590 patch_instruction(q, translate_branch(q, p)); 591 check(instr_is_branch_to_addr(q, addr)); 592 593 /* Maximum negative case, move b . to addr + 32 MB */ 594 p = buf; 595 addr = (unsigned long)p; 596 patch_branch(p, addr, 0); 597 q = buf + 0x2000000; 598 patch_instruction(q, translate_branch(q, p)); 599 check(instr_is_branch_to_addr(p, addr)); 600 check(instr_is_branch_to_addr(q, addr)); 601 check(*q == 0x4a000000); 602 603 /* Maximum positive case, move x to x - 32 MB + 4 */ 604 p = buf + 0x2000000; 605 addr = (unsigned long)p; 606 patch_branch(p, addr, 0); 607 q = buf + 4; 608 patch_instruction(q, translate_branch(q, p)); 609 check(instr_is_branch_to_addr(p, addr)); 610 check(instr_is_branch_to_addr(q, addr)); 611 check(*q == 0x49fffffc); 612 613 /* Jump to x + 16 MB moved to x + 20 MB */ 614 p = buf; 615 addr = 0x1000000 + (unsigned long)buf; 616 patch_branch(p, addr, BRANCH_SET_LINK); 617 q = buf + 0x1400000; 618 patch_instruction(q, translate_branch(q, p)); 619 check(instr_is_branch_to_addr(p, addr)); 620 check(instr_is_branch_to_addr(q, addr)); 621 622 /* Jump to x + 16 MB moved to x - 16 MB + 4 */ 623 p = buf + 0x1000000; 624 addr = 0x2000000 + (unsigned long)buf; 625 patch_branch(p, addr, 0); 626 q = buf + 4; 627 patch_instruction(q, translate_branch(q, p)); 628 check(instr_is_branch_to_addr(p, addr)); 629 check(instr_is_branch_to_addr(q, addr)); 630 631 632 /* Conditional branch tests */ 633 634 /* Simple case, branch to self moved a little */ 635 p = buf; 636 addr = (unsigned long)p; 637 patch_instruction(p, create_cond_branch(p, addr, 0)); 638 check(instr_is_branch_to_addr(p, addr)); 639 q = p + 1; 640 patch_instruction(q, translate_branch(q, p)); 641 check(instr_is_branch_to_addr(q, addr)); 642 643 /* Maximum negative case, move b . to addr + 32 KB */ 644 p = buf; 645 addr = (unsigned long)p; 646 patch_instruction(p, create_cond_branch(p, addr, 0xFFFFFFFC)); 647 q = buf + 0x8000; 648 patch_instruction(q, translate_branch(q, p)); 649 check(instr_is_branch_to_addr(p, addr)); 650 check(instr_is_branch_to_addr(q, addr)); 651 check(*q == 0x43ff8000); 652 653 /* Maximum positive case, move x to x - 32 KB + 4 */ 654 p = buf + 0x8000; 655 addr = (unsigned long)p; 656 patch_instruction(p, create_cond_branch(p, addr, 0xFFFFFFFC)); 657 q = buf + 4; 658 patch_instruction(q, translate_branch(q, p)); 659 check(instr_is_branch_to_addr(p, addr)); 660 check(instr_is_branch_to_addr(q, addr)); 661 check(*q == 0x43ff7ffc); 662 663 /* Jump to x + 12 KB moved to x + 20 KB */ 664 p = buf; 665 addr = 0x3000 + (unsigned long)buf; 666 patch_instruction(p, create_cond_branch(p, addr, BRANCH_SET_LINK)); 667 q = buf + 0x5000; 668 patch_instruction(q, translate_branch(q, p)); 669 check(instr_is_branch_to_addr(p, addr)); 670 check(instr_is_branch_to_addr(q, addr)); 671 672 /* Jump to x + 8 KB moved to x - 8 KB + 4 */ 673 p = buf + 0x2000; 674 addr = 0x4000 + (unsigned long)buf; 675 patch_instruction(p, create_cond_branch(p, addr, 0)); 676 q = buf + 4; 677 patch_instruction(q, translate_branch(q, p)); 678 check(instr_is_branch_to_addr(p, addr)); 679 check(instr_is_branch_to_addr(q, addr)); 680 681 /* Free the buffer we were using */ 682 vfree(buf); 683 } 684 685 static int __init test_code_patching(void) 686 { 687 printk(KERN_DEBUG "Running code patching self-tests ...\n"); 688 689 test_branch_iform(); 690 test_branch_bform(); 691 test_create_function_call(); 692 test_translate_branch(); 693 694 return 0; 695 } 696 late_initcall(test_code_patching); 697 698 #endif /* CONFIG_CODE_PATCHING_SELFTEST */ 699