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), PAGE_KERNEL); 102 103 pr_devel("Mapped addr %lx with pfn %lx:%d\n", text_poke_addr, pfn, err); 104 if (err) 105 return -1; 106 107 return 0; 108 } 109 110 static inline int unmap_patch_area(unsigned long addr) 111 { 112 pte_t *ptep; 113 pmd_t *pmdp; 114 pud_t *pudp; 115 pgd_t *pgdp; 116 117 pgdp = pgd_offset_k(addr); 118 if (unlikely(!pgdp)) 119 return -EINVAL; 120 121 pudp = pud_offset(pgdp, addr); 122 if (unlikely(!pudp)) 123 return -EINVAL; 124 125 pmdp = pmd_offset(pudp, addr); 126 if (unlikely(!pmdp)) 127 return -EINVAL; 128 129 ptep = pte_offset_kernel(pmdp, addr); 130 if (unlikely(!ptep)) 131 return -EINVAL; 132 133 pr_devel("clearing mm %p, pte %p, addr %lx\n", &init_mm, ptep, addr); 134 135 /* 136 * In hash, pte_clear flushes the tlb, in radix, we have to 137 */ 138 pte_clear(&init_mm, addr, ptep); 139 flush_tlb_kernel_range(addr, addr + PAGE_SIZE); 140 141 return 0; 142 } 143 144 static int do_patch_instruction(unsigned int *addr, unsigned int instr) 145 { 146 int err; 147 unsigned int *patch_addr = NULL; 148 unsigned long flags; 149 unsigned long text_poke_addr; 150 unsigned long kaddr = (unsigned long)addr; 151 152 /* 153 * During early early boot patch_instruction is called 154 * when text_poke_area is not ready, but we still need 155 * to allow patching. We just do the plain old patching 156 */ 157 if (!this_cpu_read(text_poke_area)) 158 return raw_patch_instruction(addr, instr); 159 160 local_irq_save(flags); 161 162 text_poke_addr = (unsigned long)__this_cpu_read(text_poke_area)->addr; 163 if (map_patch_area(addr, text_poke_addr)) { 164 err = -1; 165 goto out; 166 } 167 168 patch_addr = (unsigned int *)(text_poke_addr) + 169 ((kaddr & ~PAGE_MASK) / sizeof(unsigned int)); 170 171 __patch_instruction(addr, instr, patch_addr); 172 173 err = unmap_patch_area(text_poke_addr); 174 if (err) 175 pr_warn("failed to unmap %lx\n", text_poke_addr); 176 177 out: 178 local_irq_restore(flags); 179 180 return err; 181 } 182 #else /* !CONFIG_STRICT_KERNEL_RWX */ 183 184 static int do_patch_instruction(unsigned int *addr, unsigned int instr) 185 { 186 return raw_patch_instruction(addr, instr); 187 } 188 189 #endif /* CONFIG_STRICT_KERNEL_RWX */ 190 191 int patch_instruction(unsigned int *addr, unsigned int instr) 192 { 193 /* Make sure we aren't patching a freed init section */ 194 if (init_mem_is_free && init_section_contains(addr, 4)) { 195 pr_debug("Skipping init section patching addr: 0x%px\n", addr); 196 return 0; 197 } 198 return do_patch_instruction(addr, instr); 199 } 200 NOKPROBE_SYMBOL(patch_instruction); 201 202 int patch_branch(unsigned int *addr, unsigned long target, int flags) 203 { 204 return patch_instruction(addr, create_branch(addr, target, flags)); 205 } 206 207 int patch_branch_site(s32 *site, unsigned long target, int flags) 208 { 209 unsigned int *addr; 210 211 addr = (unsigned int *)((unsigned long)site + *site); 212 return patch_instruction(addr, create_branch(addr, target, flags)); 213 } 214 215 int patch_instruction_site(s32 *site, unsigned int instr) 216 { 217 unsigned int *addr; 218 219 addr = (unsigned int *)((unsigned long)site + *site); 220 return patch_instruction(addr, instr); 221 } 222 223 bool is_offset_in_branch_range(long offset) 224 { 225 /* 226 * Powerpc branch instruction is : 227 * 228 * 0 6 30 31 229 * +---------+----------------+---+---+ 230 * | opcode | LI |AA |LK | 231 * +---------+----------------+---+---+ 232 * Where AA = 0 and LK = 0 233 * 234 * LI is a signed 24 bits integer. The real branch offset is computed 235 * by: imm32 = SignExtend(LI:'0b00', 32); 236 * 237 * So the maximum forward branch should be: 238 * (0x007fffff << 2) = 0x01fffffc = 0x1fffffc 239 * The maximum backward branch should be: 240 * (0xff800000 << 2) = 0xfe000000 = -0x2000000 241 */ 242 return (offset >= -0x2000000 && offset <= 0x1fffffc && !(offset & 0x3)); 243 } 244 245 /* 246 * Helper to check if a given instruction is a conditional branch 247 * Derived from the conditional checks in analyse_instr() 248 */ 249 bool is_conditional_branch(unsigned int instr) 250 { 251 unsigned int opcode = instr >> 26; 252 253 if (opcode == 16) /* bc, bca, bcl, bcla */ 254 return true; 255 if (opcode == 19) { 256 switch ((instr >> 1) & 0x3ff) { 257 case 16: /* bclr, bclrl */ 258 case 528: /* bcctr, bcctrl */ 259 case 560: /* bctar, bctarl */ 260 return true; 261 } 262 } 263 return false; 264 } 265 NOKPROBE_SYMBOL(is_conditional_branch); 266 267 unsigned int create_branch(const unsigned int *addr, 268 unsigned long target, int flags) 269 { 270 unsigned int instruction; 271 long offset; 272 273 offset = target; 274 if (! (flags & BRANCH_ABSOLUTE)) 275 offset = offset - (unsigned long)addr; 276 277 /* Check we can represent the target in the instruction format */ 278 if (!is_offset_in_branch_range(offset)) 279 return 0; 280 281 /* Mask out the flags and target, so they don't step on each other. */ 282 instruction = 0x48000000 | (flags & 0x3) | (offset & 0x03FFFFFC); 283 284 return instruction; 285 } 286 287 unsigned int create_cond_branch(const unsigned int *addr, 288 unsigned long target, int flags) 289 { 290 unsigned int instruction; 291 long offset; 292 293 offset = target; 294 if (! (flags & BRANCH_ABSOLUTE)) 295 offset = offset - (unsigned long)addr; 296 297 /* Check we can represent the target in the instruction format */ 298 if (offset < -0x8000 || offset > 0x7FFF || offset & 0x3) 299 return 0; 300 301 /* Mask out the flags and target, so they don't step on each other. */ 302 instruction = 0x40000000 | (flags & 0x3FF0003) | (offset & 0xFFFC); 303 304 return instruction; 305 } 306 307 static unsigned int branch_opcode(unsigned int instr) 308 { 309 return (instr >> 26) & 0x3F; 310 } 311 312 static int instr_is_branch_iform(unsigned int instr) 313 { 314 return branch_opcode(instr) == 18; 315 } 316 317 static int instr_is_branch_bform(unsigned int instr) 318 { 319 return branch_opcode(instr) == 16; 320 } 321 322 int instr_is_relative_branch(unsigned int instr) 323 { 324 if (instr & BRANCH_ABSOLUTE) 325 return 0; 326 327 return instr_is_branch_iform(instr) || instr_is_branch_bform(instr); 328 } 329 330 int instr_is_relative_link_branch(unsigned int instr) 331 { 332 return instr_is_relative_branch(instr) && (instr & BRANCH_SET_LINK); 333 } 334 335 static unsigned long branch_iform_target(const unsigned int *instr) 336 { 337 signed long imm; 338 339 imm = *instr & 0x3FFFFFC; 340 341 /* If the top bit of the immediate value is set this is negative */ 342 if (imm & 0x2000000) 343 imm -= 0x4000000; 344 345 if ((*instr & BRANCH_ABSOLUTE) == 0) 346 imm += (unsigned long)instr; 347 348 return (unsigned long)imm; 349 } 350 351 static unsigned long branch_bform_target(const unsigned int *instr) 352 { 353 signed long imm; 354 355 imm = *instr & 0xFFFC; 356 357 /* If the top bit of the immediate value is set this is negative */ 358 if (imm & 0x8000) 359 imm -= 0x10000; 360 361 if ((*instr & BRANCH_ABSOLUTE) == 0) 362 imm += (unsigned long)instr; 363 364 return (unsigned long)imm; 365 } 366 367 unsigned long branch_target(const unsigned int *instr) 368 { 369 if (instr_is_branch_iform(*instr)) 370 return branch_iform_target(instr); 371 else if (instr_is_branch_bform(*instr)) 372 return branch_bform_target(instr); 373 374 return 0; 375 } 376 377 int instr_is_branch_to_addr(const unsigned int *instr, unsigned long addr) 378 { 379 if (instr_is_branch_iform(*instr) || instr_is_branch_bform(*instr)) 380 return branch_target(instr) == addr; 381 382 return 0; 383 } 384 385 unsigned int translate_branch(const unsigned int *dest, const unsigned int *src) 386 { 387 unsigned long target; 388 389 target = branch_target(src); 390 391 if (instr_is_branch_iform(*src)) 392 return create_branch(dest, target, *src); 393 else if (instr_is_branch_bform(*src)) 394 return create_cond_branch(dest, target, *src); 395 396 return 0; 397 } 398 399 #ifdef CONFIG_PPC_BOOK3E_64 400 void __patch_exception(int exc, unsigned long addr) 401 { 402 extern unsigned int interrupt_base_book3e; 403 unsigned int *ibase = &interrupt_base_book3e; 404 405 /* Our exceptions vectors start with a NOP and -then- a branch 406 * to deal with single stepping from userspace which stops on 407 * the second instruction. Thus we need to patch the second 408 * instruction of the exception, not the first one 409 */ 410 411 patch_branch(ibase + (exc / 4) + 1, addr, 0); 412 } 413 #endif 414 415 #ifdef CONFIG_CODE_PATCHING_SELFTEST 416 417 static void __init test_trampoline(void) 418 { 419 asm ("nop;\n"); 420 } 421 422 #define check(x) \ 423 if (!(x)) printk("code-patching: test failed at line %d\n", __LINE__); 424 425 static void __init test_branch_iform(void) 426 { 427 unsigned int instr; 428 unsigned long addr; 429 430 addr = (unsigned long)&instr; 431 432 /* The simplest case, branch to self, no flags */ 433 check(instr_is_branch_iform(0x48000000)); 434 /* All bits of target set, and flags */ 435 check(instr_is_branch_iform(0x4bffffff)); 436 /* High bit of opcode set, which is wrong */ 437 check(!instr_is_branch_iform(0xcbffffff)); 438 /* Middle bits of opcode set, which is wrong */ 439 check(!instr_is_branch_iform(0x7bffffff)); 440 441 /* Simplest case, branch to self with link */ 442 check(instr_is_branch_iform(0x48000001)); 443 /* All bits of targets set */ 444 check(instr_is_branch_iform(0x4bfffffd)); 445 /* Some bits of targets set */ 446 check(instr_is_branch_iform(0x4bff00fd)); 447 /* Must be a valid branch to start with */ 448 check(!instr_is_branch_iform(0x7bfffffd)); 449 450 /* Absolute branch to 0x100 */ 451 instr = 0x48000103; 452 check(instr_is_branch_to_addr(&instr, 0x100)); 453 /* Absolute branch to 0x420fc */ 454 instr = 0x480420ff; 455 check(instr_is_branch_to_addr(&instr, 0x420fc)); 456 /* Maximum positive relative branch, + 20MB - 4B */ 457 instr = 0x49fffffc; 458 check(instr_is_branch_to_addr(&instr, addr + 0x1FFFFFC)); 459 /* Smallest negative relative branch, - 4B */ 460 instr = 0x4bfffffc; 461 check(instr_is_branch_to_addr(&instr, addr - 4)); 462 /* Largest negative relative branch, - 32 MB */ 463 instr = 0x4a000000; 464 check(instr_is_branch_to_addr(&instr, addr - 0x2000000)); 465 466 /* Branch to self, with link */ 467 instr = create_branch(&instr, addr, BRANCH_SET_LINK); 468 check(instr_is_branch_to_addr(&instr, addr)); 469 470 /* Branch to self - 0x100, with link */ 471 instr = create_branch(&instr, addr - 0x100, BRANCH_SET_LINK); 472 check(instr_is_branch_to_addr(&instr, addr - 0x100)); 473 474 /* Branch to self + 0x100, no link */ 475 instr = create_branch(&instr, addr + 0x100, 0); 476 check(instr_is_branch_to_addr(&instr, addr + 0x100)); 477 478 /* Maximum relative negative offset, - 32 MB */ 479 instr = create_branch(&instr, addr - 0x2000000, BRANCH_SET_LINK); 480 check(instr_is_branch_to_addr(&instr, addr - 0x2000000)); 481 482 /* Out of range relative negative offset, - 32 MB + 4*/ 483 instr = create_branch(&instr, addr - 0x2000004, BRANCH_SET_LINK); 484 check(instr == 0); 485 486 /* Out of range relative positive offset, + 32 MB */ 487 instr = create_branch(&instr, addr + 0x2000000, BRANCH_SET_LINK); 488 check(instr == 0); 489 490 /* Unaligned target */ 491 instr = create_branch(&instr, addr + 3, BRANCH_SET_LINK); 492 check(instr == 0); 493 494 /* Check flags are masked correctly */ 495 instr = create_branch(&instr, addr, 0xFFFFFFFC); 496 check(instr_is_branch_to_addr(&instr, addr)); 497 check(instr == 0x48000000); 498 } 499 500 static void __init test_create_function_call(void) 501 { 502 unsigned int *iptr; 503 unsigned long dest; 504 505 /* Check we can create a function call */ 506 iptr = (unsigned int *)ppc_function_entry(test_trampoline); 507 dest = ppc_function_entry(test_create_function_call); 508 patch_instruction(iptr, create_branch(iptr, dest, BRANCH_SET_LINK)); 509 check(instr_is_branch_to_addr(iptr, dest)); 510 } 511 512 static void __init test_branch_bform(void) 513 { 514 unsigned long addr; 515 unsigned int *iptr, instr, flags; 516 517 iptr = &instr; 518 addr = (unsigned long)iptr; 519 520 /* The simplest case, branch to self, no flags */ 521 check(instr_is_branch_bform(0x40000000)); 522 /* All bits of target set, and flags */ 523 check(instr_is_branch_bform(0x43ffffff)); 524 /* High bit of opcode set, which is wrong */ 525 check(!instr_is_branch_bform(0xc3ffffff)); 526 /* Middle bits of opcode set, which is wrong */ 527 check(!instr_is_branch_bform(0x7bffffff)); 528 529 /* Absolute conditional branch to 0x100 */ 530 instr = 0x43ff0103; 531 check(instr_is_branch_to_addr(&instr, 0x100)); 532 /* Absolute conditional branch to 0x20fc */ 533 instr = 0x43ff20ff; 534 check(instr_is_branch_to_addr(&instr, 0x20fc)); 535 /* Maximum positive relative conditional branch, + 32 KB - 4B */ 536 instr = 0x43ff7ffc; 537 check(instr_is_branch_to_addr(&instr, addr + 0x7FFC)); 538 /* Smallest negative relative conditional branch, - 4B */ 539 instr = 0x43fffffc; 540 check(instr_is_branch_to_addr(&instr, addr - 4)); 541 /* Largest negative relative conditional branch, - 32 KB */ 542 instr = 0x43ff8000; 543 check(instr_is_branch_to_addr(&instr, addr - 0x8000)); 544 545 /* All condition code bits set & link */ 546 flags = 0x3ff000 | BRANCH_SET_LINK; 547 548 /* Branch to self */ 549 instr = create_cond_branch(iptr, addr, flags); 550 check(instr_is_branch_to_addr(&instr, addr)); 551 552 /* Branch to self - 0x100 */ 553 instr = create_cond_branch(iptr, addr - 0x100, flags); 554 check(instr_is_branch_to_addr(&instr, addr - 0x100)); 555 556 /* Branch to self + 0x100 */ 557 instr = create_cond_branch(iptr, addr + 0x100, flags); 558 check(instr_is_branch_to_addr(&instr, addr + 0x100)); 559 560 /* Maximum relative negative offset, - 32 KB */ 561 instr = create_cond_branch(iptr, addr - 0x8000, flags); 562 check(instr_is_branch_to_addr(&instr, addr - 0x8000)); 563 564 /* Out of range relative negative offset, - 32 KB + 4*/ 565 instr = create_cond_branch(iptr, addr - 0x8004, flags); 566 check(instr == 0); 567 568 /* Out of range relative positive offset, + 32 KB */ 569 instr = create_cond_branch(iptr, addr + 0x8000, flags); 570 check(instr == 0); 571 572 /* Unaligned target */ 573 instr = create_cond_branch(iptr, addr + 3, flags); 574 check(instr == 0); 575 576 /* Check flags are masked correctly */ 577 instr = create_cond_branch(iptr, addr, 0xFFFFFFFC); 578 check(instr_is_branch_to_addr(&instr, addr)); 579 check(instr == 0x43FF0000); 580 } 581 582 static void __init test_translate_branch(void) 583 { 584 unsigned long addr; 585 unsigned int *p, *q; 586 void *buf; 587 588 buf = vmalloc(PAGE_ALIGN(0x2000000 + 1)); 589 check(buf); 590 if (!buf) 591 return; 592 593 /* Simple case, branch to self moved a little */ 594 p = buf; 595 addr = (unsigned long)p; 596 patch_branch(p, addr, 0); 597 check(instr_is_branch_to_addr(p, addr)); 598 q = p + 1; 599 patch_instruction(q, translate_branch(q, p)); 600 check(instr_is_branch_to_addr(q, addr)); 601 602 /* Maximum negative case, move b . to addr + 32 MB */ 603 p = buf; 604 addr = (unsigned long)p; 605 patch_branch(p, addr, 0); 606 q = buf + 0x2000000; 607 patch_instruction(q, translate_branch(q, p)); 608 check(instr_is_branch_to_addr(p, addr)); 609 check(instr_is_branch_to_addr(q, addr)); 610 check(*q == 0x4a000000); 611 612 /* Maximum positive case, move x to x - 32 MB + 4 */ 613 p = buf + 0x2000000; 614 addr = (unsigned long)p; 615 patch_branch(p, addr, 0); 616 q = buf + 4; 617 patch_instruction(q, translate_branch(q, p)); 618 check(instr_is_branch_to_addr(p, addr)); 619 check(instr_is_branch_to_addr(q, addr)); 620 check(*q == 0x49fffffc); 621 622 /* Jump to x + 16 MB moved to x + 20 MB */ 623 p = buf; 624 addr = 0x1000000 + (unsigned long)buf; 625 patch_branch(p, addr, BRANCH_SET_LINK); 626 q = buf + 0x1400000; 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 /* Jump to x + 16 MB moved to x - 16 MB + 4 */ 632 p = buf + 0x1000000; 633 addr = 0x2000000 + (unsigned long)buf; 634 patch_branch(p, addr, 0); 635 q = buf + 4; 636 patch_instruction(q, translate_branch(q, p)); 637 check(instr_is_branch_to_addr(p, addr)); 638 check(instr_is_branch_to_addr(q, addr)); 639 640 641 /* Conditional branch tests */ 642 643 /* Simple case, branch to self moved a little */ 644 p = buf; 645 addr = (unsigned long)p; 646 patch_instruction(p, create_cond_branch(p, addr, 0)); 647 check(instr_is_branch_to_addr(p, addr)); 648 q = p + 1; 649 patch_instruction(q, translate_branch(q, p)); 650 check(instr_is_branch_to_addr(q, addr)); 651 652 /* Maximum negative case, move b . to addr + 32 KB */ 653 p = buf; 654 addr = (unsigned long)p; 655 patch_instruction(p, create_cond_branch(p, addr, 0xFFFFFFFC)); 656 q = buf + 0x8000; 657 patch_instruction(q, translate_branch(q, p)); 658 check(instr_is_branch_to_addr(p, addr)); 659 check(instr_is_branch_to_addr(q, addr)); 660 check(*q == 0x43ff8000); 661 662 /* Maximum positive case, move x to x - 32 KB + 4 */ 663 p = buf + 0x8000; 664 addr = (unsigned long)p; 665 patch_instruction(p, create_cond_branch(p, addr, 0xFFFFFFFC)); 666 q = buf + 4; 667 patch_instruction(q, translate_branch(q, p)); 668 check(instr_is_branch_to_addr(p, addr)); 669 check(instr_is_branch_to_addr(q, addr)); 670 check(*q == 0x43ff7ffc); 671 672 /* Jump to x + 12 KB moved to x + 20 KB */ 673 p = buf; 674 addr = 0x3000 + (unsigned long)buf; 675 patch_instruction(p, create_cond_branch(p, addr, BRANCH_SET_LINK)); 676 q = buf + 0x5000; 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 /* Jump to x + 8 KB moved to x - 8 KB + 4 */ 682 p = buf + 0x2000; 683 addr = 0x4000 + (unsigned long)buf; 684 patch_instruction(p, create_cond_branch(p, addr, 0)); 685 q = buf + 4; 686 patch_instruction(q, translate_branch(q, p)); 687 check(instr_is_branch_to_addr(p, addr)); 688 check(instr_is_branch_to_addr(q, addr)); 689 690 /* Free the buffer we were using */ 691 vfree(buf); 692 } 693 694 static int __init test_code_patching(void) 695 { 696 printk(KERN_DEBUG "Running code patching self-tests ...\n"); 697 698 test_branch_iform(); 699 test_branch_bform(); 700 test_create_function_call(); 701 test_translate_branch(); 702 703 return 0; 704 } 705 late_initcall(test_code_patching); 706 707 #endif /* CONFIG_CODE_PATCHING_SELFTEST */ 708