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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 | // SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright 2008 Michael Ellerman, IBM Corporation. */ #include <linux/kernel.h> #include <linux/kprobes.h> #include <linux/vmalloc.h> #include <linux/init.h> #include <linux/mm.h> #include <linux/cpuhotplug.h> #include <linux/slab.h> #include <linux/uaccess.h> #include <asm/tlbflush.h> #include <asm/page.h> #include <asm/code-patching.h> #include <asm/setup.h> #include <asm/inst.h> static int __patch_instruction(struct ppc_inst *exec_addr, struct ppc_inst instr, struct ppc_inst *patch_addr) { if (!ppc_inst_prefixed(instr)) __put_user_asm_goto(ppc_inst_val(instr), patch_addr, failed, "stw"); else __put_user_asm_goto(ppc_inst_as_u64(instr), patch_addr, failed, "std"); asm ("dcbst 0, %0; sync; icbi 0,%1; sync; isync" :: "r" (patch_addr), "r" (exec_addr)); return 0; failed: return -EFAULT; } int raw_patch_instruction(struct ppc_inst *addr, struct ppc_inst instr) { return __patch_instruction(addr, instr, addr); } #ifdef CONFIG_STRICT_KERNEL_RWX static DEFINE_PER_CPU(struct vm_struct *, text_poke_area); static int text_area_cpu_up(unsigned int cpu) { struct vm_struct *area; area = get_vm_area(PAGE_SIZE, VM_ALLOC); if (!area) { WARN_ONCE(1, "Failed to create text area for cpu %d\n", cpu); return -1; } this_cpu_write(text_poke_area, area); return 0; } static int text_area_cpu_down(unsigned int cpu) { free_vm_area(this_cpu_read(text_poke_area)); return 0; } /* * Run as a late init call. This allows all the boot time patching to be done * simply by patching the code, and then we're called here prior to * mark_rodata_ro(), which happens after all init calls are run. Although * BUG_ON() is rude, in this case it should only happen if ENOMEM, and we judge * it as being preferable to a kernel that will crash later when someone tries * to use patch_instruction(). */ static int __init setup_text_poke_area(void) { BUG_ON(!cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "powerpc/text_poke:online", text_area_cpu_up, text_area_cpu_down)); return 0; } late_initcall(setup_text_poke_area); /* * This can be called for kernel text or a module. */ static int map_patch_area(void *addr, unsigned long text_poke_addr) { unsigned long pfn; int err; if (is_vmalloc_or_module_addr(addr)) pfn = vmalloc_to_pfn(addr); else pfn = __pa_symbol(addr) >> PAGE_SHIFT; err = map_kernel_page(text_poke_addr, (pfn << PAGE_SHIFT), PAGE_KERNEL); pr_devel("Mapped addr %lx with pfn %lx:%d\n", text_poke_addr, pfn, err); if (err) return -1; return 0; } static inline int unmap_patch_area(unsigned long addr) { pte_t *ptep; pmd_t *pmdp; pud_t *pudp; p4d_t *p4dp; pgd_t *pgdp; pgdp = pgd_offset_k(addr); if (unlikely(!pgdp)) return -EINVAL; p4dp = p4d_offset(pgdp, addr); if (unlikely(!p4dp)) return -EINVAL; pudp = pud_offset(p4dp, addr); if (unlikely(!pudp)) return -EINVAL; pmdp = pmd_offset(pudp, addr); if (unlikely(!pmdp)) return -EINVAL; ptep = pte_offset_kernel(pmdp, addr); if (unlikely(!ptep)) return -EINVAL; pr_devel("clearing mm %p, pte %p, addr %lx\n", &init_mm, ptep, addr); /* * In hash, pte_clear flushes the tlb, in radix, we have to */ pte_clear(&init_mm, addr, ptep); flush_tlb_kernel_range(addr, addr + PAGE_SIZE); return 0; } static int do_patch_instruction(struct ppc_inst *addr, struct ppc_inst instr) { int err; struct ppc_inst *patch_addr = NULL; unsigned long flags; unsigned long text_poke_addr; unsigned long kaddr = (unsigned long)addr; /* * During early early boot patch_instruction is called * when text_poke_area is not ready, but we still need * to allow patching. We just do the plain old patching */ if (!this_cpu_read(text_poke_area)) return raw_patch_instruction(addr, instr); local_irq_save(flags); text_poke_addr = (unsigned long)__this_cpu_read(text_poke_area)->addr; if (map_patch_area(addr, text_poke_addr)) { err = -1; goto out; } patch_addr = (struct ppc_inst *)(text_poke_addr + (kaddr & ~PAGE_MASK)); __patch_instruction(addr, instr, patch_addr); err = unmap_patch_area(text_poke_addr); if (err) pr_warn("failed to unmap %lx\n", text_poke_addr); out: local_irq_restore(flags); return err; } #else /* !CONFIG_STRICT_KERNEL_RWX */ static int do_patch_instruction(struct ppc_inst *addr, struct ppc_inst instr) { return raw_patch_instruction(addr, instr); } #endif /* CONFIG_STRICT_KERNEL_RWX */ int patch_instruction(struct ppc_inst *addr, struct ppc_inst instr) { /* Make sure we aren't patching a freed init section */ if (init_mem_is_free && init_section_contains(addr, 4)) { pr_debug("Skipping init section patching addr: 0x%px\n", addr); return 0; } return do_patch_instruction(addr, instr); } NOKPROBE_SYMBOL(patch_instruction); int patch_branch(struct ppc_inst *addr, unsigned long target, int flags) { struct ppc_inst instr; create_branch(&instr, addr, target, flags); return patch_instruction(addr, instr); } bool is_offset_in_branch_range(long offset) { /* * Powerpc branch instruction is : * * 0 6 30 31 * +---------+----------------+---+---+ * | opcode | LI |AA |LK | * +---------+----------------+---+---+ * Where AA = 0 and LK = 0 * * LI is a signed 24 bits integer. The real branch offset is computed * by: imm32 = SignExtend(LI:'0b00', 32); * * So the maximum forward branch should be: * (0x007fffff << 2) = 0x01fffffc = 0x1fffffc * The maximum backward branch should be: * (0xff800000 << 2) = 0xfe000000 = -0x2000000 */ return (offset >= -0x2000000 && offset <= 0x1fffffc && !(offset & 0x3)); } bool is_offset_in_cond_branch_range(long offset) { return offset >= -0x8000 && offset <= 0x7fff && !(offset & 0x3); } /* * Helper to check if a given instruction is a conditional branch * Derived from the conditional checks in analyse_instr() */ bool is_conditional_branch(struct ppc_inst instr) { unsigned int opcode = ppc_inst_primary_opcode(instr); if (opcode == 16) /* bc, bca, bcl, bcla */ return true; if (opcode == 19) { switch ((ppc_inst_val(instr) >> 1) & 0x3ff) { case 16: /* bclr, bclrl */ case 528: /* bcctr, bcctrl */ case 560: /* bctar, bctarl */ return true; } } return false; } NOKPROBE_SYMBOL(is_conditional_branch); int create_branch(struct ppc_inst *instr, const struct ppc_inst *addr, unsigned long target, int flags) { long offset; *instr = ppc_inst(0); offset = target; if (! (flags & BRANCH_ABSOLUTE)) offset = offset - (unsigned long)addr; /* Check we can represent the target in the instruction format */ if (!is_offset_in_branch_range(offset)) return 1; /* Mask out the flags and target, so they don't step on each other. */ *instr = ppc_inst(0x48000000 | (flags & 0x3) | (offset & 0x03FFFFFC)); return 0; } int create_cond_branch(struct ppc_inst *instr, const struct ppc_inst *addr, unsigned long target, int flags) { long offset; offset = target; if (! (flags & BRANCH_ABSOLUTE)) offset = offset - (unsigned long)addr; /* Check we can represent the target in the instruction format */ if (!is_offset_in_cond_branch_range(offset)) return 1; /* Mask out the flags and target, so they don't step on each other. */ *instr = ppc_inst(0x40000000 | (flags & 0x3FF0003) | (offset & 0xFFFC)); return 0; } static unsigned int branch_opcode(struct ppc_inst instr) { return ppc_inst_primary_opcode(instr) & 0x3F; } static int instr_is_branch_iform(struct ppc_inst instr) { return branch_opcode(instr) == 18; } static int instr_is_branch_bform(struct ppc_inst instr) { return branch_opcode(instr) == 16; } int instr_is_relative_branch(struct ppc_inst instr) { if (ppc_inst_val(instr) & BRANCH_ABSOLUTE) return 0; return instr_is_branch_iform(instr) || instr_is_branch_bform(instr); } int instr_is_relative_link_branch(struct ppc_inst instr) { return instr_is_relative_branch(instr) && (ppc_inst_val(instr) & BRANCH_SET_LINK); } static unsigned long branch_iform_target(const struct ppc_inst *instr) { signed long imm; imm = ppc_inst_val(*instr) & 0x3FFFFFC; /* If the top bit of the immediate value is set this is negative */ if (imm & 0x2000000) imm -= 0x4000000; if ((ppc_inst_val(*instr) & BRANCH_ABSOLUTE) == 0) imm += (unsigned long)instr; return (unsigned long)imm; } static unsigned long branch_bform_target(const struct ppc_inst *instr) { signed long imm; imm = ppc_inst_val(*instr) & 0xFFFC; /* If the top bit of the immediate value is set this is negative */ if (imm & 0x8000) imm -= 0x10000; if ((ppc_inst_val(*instr) & BRANCH_ABSOLUTE) == 0) imm += (unsigned long)instr; return (unsigned long)imm; } unsigned long branch_target(const struct ppc_inst *instr) { if (instr_is_branch_iform(ppc_inst_read(instr))) return branch_iform_target(instr); else if (instr_is_branch_bform(ppc_inst_read(instr))) return branch_bform_target(instr); return 0; } int instr_is_branch_to_addr(const struct ppc_inst *instr, unsigned long addr) { if (instr_is_branch_iform(ppc_inst_read(instr)) || instr_is_branch_bform(ppc_inst_read(instr))) return branch_target(instr) == addr; return 0; } int translate_branch(struct ppc_inst *instr, const struct ppc_inst *dest, const struct ppc_inst *src) { unsigned long target; target = branch_target(src); if (instr_is_branch_iform(ppc_inst_read(src))) return create_branch(instr, dest, target, ppc_inst_val(ppc_inst_read(src))); else if (instr_is_branch_bform(ppc_inst_read(src))) return create_cond_branch(instr, dest, target, ppc_inst_val(ppc_inst_read(src))); return 1; } #ifdef CONFIG_PPC_BOOK3E_64 void __patch_exception(int exc, unsigned long addr) { extern unsigned int interrupt_base_book3e; unsigned int *ibase = &interrupt_base_book3e; /* Our exceptions vectors start with a NOP and -then- a branch * to deal with single stepping from userspace which stops on * the second instruction. Thus we need to patch the second * instruction of the exception, not the first one */ patch_branch((struct ppc_inst *)(ibase + (exc / 4) + 1), addr, 0); } #endif #ifdef CONFIG_CODE_PATCHING_SELFTEST static void __init test_trampoline(void) { asm ("nop;\n"); } #define check(x) \ if (!(x)) printk("code-patching: test failed at line %d\n", __LINE__); static void __init test_branch_iform(void) { int err; struct ppc_inst instr; unsigned long addr; addr = (unsigned long)&instr; /* The simplest case, branch to self, no flags */ check(instr_is_branch_iform(ppc_inst(0x48000000))); /* All bits of target set, and flags */ check(instr_is_branch_iform(ppc_inst(0x4bffffff))); /* High bit of opcode set, which is wrong */ check(!instr_is_branch_iform(ppc_inst(0xcbffffff))); /* Middle bits of opcode set, which is wrong */ check(!instr_is_branch_iform(ppc_inst(0x7bffffff))); /* Simplest case, branch to self with link */ check(instr_is_branch_iform(ppc_inst(0x48000001))); /* All bits of targets set */ check(instr_is_branch_iform(ppc_inst(0x4bfffffd))); /* Some bits of targets set */ check(instr_is_branch_iform(ppc_inst(0x4bff00fd))); /* Must be a valid branch to start with */ check(!instr_is_branch_iform(ppc_inst(0x7bfffffd))); /* Absolute branch to 0x100 */ instr = ppc_inst(0x48000103); check(instr_is_branch_to_addr(&instr, 0x100)); /* Absolute branch to 0x420fc */ instr = ppc_inst(0x480420ff); check(instr_is_branch_to_addr(&instr, 0x420fc)); /* Maximum positive relative branch, + 20MB - 4B */ instr = ppc_inst(0x49fffffc); check(instr_is_branch_to_addr(&instr, addr + 0x1FFFFFC)); /* Smallest negative relative branch, - 4B */ instr = ppc_inst(0x4bfffffc); check(instr_is_branch_to_addr(&instr, addr - 4)); /* Largest negative relative branch, - 32 MB */ instr = ppc_inst(0x4a000000); check(instr_is_branch_to_addr(&instr, addr - 0x2000000)); /* Branch to self, with link */ err = create_branch(&instr, &instr, addr, BRANCH_SET_LINK); check(instr_is_branch_to_addr(&instr, addr)); /* Branch to self - 0x100, with link */ err = create_branch(&instr, &instr, addr - 0x100, BRANCH_SET_LINK); check(instr_is_branch_to_addr(&instr, addr - 0x100)); /* Branch to self + 0x100, no link */ err = create_branch(&instr, &instr, addr + 0x100, 0); check(instr_is_branch_to_addr(&instr, addr + 0x100)); /* Maximum relative negative offset, - 32 MB */ err = create_branch(&instr, &instr, addr - 0x2000000, BRANCH_SET_LINK); check(instr_is_branch_to_addr(&instr, addr - 0x2000000)); /* Out of range relative negative offset, - 32 MB + 4*/ err = create_branch(&instr, &instr, addr - 0x2000004, BRANCH_SET_LINK); check(err); /* Out of range relative positive offset, + 32 MB */ err = create_branch(&instr, &instr, addr + 0x2000000, BRANCH_SET_LINK); check(err); /* Unaligned target */ err = create_branch(&instr, &instr, addr + 3, BRANCH_SET_LINK); check(err); /* Check flags are masked correctly */ err = create_branch(&instr, &instr, addr, 0xFFFFFFFC); check(instr_is_branch_to_addr(&instr, addr)); check(ppc_inst_equal(instr, ppc_inst(0x48000000))); } static void __init test_create_function_call(void) { struct ppc_inst *iptr; unsigned long dest; struct ppc_inst instr; /* Check we can create a function call */ iptr = (struct ppc_inst *)ppc_function_entry(test_trampoline); dest = ppc_function_entry(test_create_function_call); create_branch(&instr, iptr, dest, BRANCH_SET_LINK); patch_instruction(iptr, instr); check(instr_is_branch_to_addr(iptr, dest)); } static void __init test_branch_bform(void) { int err; unsigned long addr; struct ppc_inst *iptr, instr; unsigned int flags; iptr = &instr; addr = (unsigned long)iptr; /* The simplest case, branch to self, no flags */ check(instr_is_branch_bform(ppc_inst(0x40000000))); /* All bits of target set, and flags */ check(instr_is_branch_bform(ppc_inst(0x43ffffff))); /* High bit of opcode set, which is wrong */ check(!instr_is_branch_bform(ppc_inst(0xc3ffffff))); /* Middle bits of opcode set, which is wrong */ check(!instr_is_branch_bform(ppc_inst(0x7bffffff))); /* Absolute conditional branch to 0x100 */ instr = ppc_inst(0x43ff0103); check(instr_is_branch_to_addr(&instr, 0x100)); /* Absolute conditional branch to 0x20fc */ instr = ppc_inst(0x43ff20ff); check(instr_is_branch_to_addr(&instr, 0x20fc)); /* Maximum positive relative conditional branch, + 32 KB - 4B */ instr = ppc_inst(0x43ff7ffc); check(instr_is_branch_to_addr(&instr, addr + 0x7FFC)); /* Smallest negative relative conditional branch, - 4B */ instr = ppc_inst(0x43fffffc); check(instr_is_branch_to_addr(&instr, addr - 4)); /* Largest negative relative conditional branch, - 32 KB */ instr = ppc_inst(0x43ff8000); check(instr_is_branch_to_addr(&instr, addr - 0x8000)); /* All condition code bits set & link */ flags = 0x3ff000 | BRANCH_SET_LINK; /* Branch to self */ err = create_cond_branch(&instr, iptr, addr, flags); check(instr_is_branch_to_addr(&instr, addr)); /* Branch to self - 0x100 */ err = create_cond_branch(&instr, iptr, addr - 0x100, flags); check(instr_is_branch_to_addr(&instr, addr - 0x100)); /* Branch to self + 0x100 */ err = create_cond_branch(&instr, iptr, addr + 0x100, flags); check(instr_is_branch_to_addr(&instr, addr + 0x100)); /* Maximum relative negative offset, - 32 KB */ err = create_cond_branch(&instr, iptr, addr - 0x8000, flags); check(instr_is_branch_to_addr(&instr, addr - 0x8000)); /* Out of range relative negative offset, - 32 KB + 4*/ err = create_cond_branch(&instr, iptr, addr - 0x8004, flags); check(err); /* Out of range relative positive offset, + 32 KB */ err = create_cond_branch(&instr, iptr, addr + 0x8000, flags); check(err); /* Unaligned target */ err = create_cond_branch(&instr, iptr, addr + 3, flags); check(err); /* Check flags are masked correctly */ err = create_cond_branch(&instr, iptr, addr, 0xFFFFFFFC); check(instr_is_branch_to_addr(&instr, addr)); check(ppc_inst_equal(instr, ppc_inst(0x43FF0000))); } static void __init test_translate_branch(void) { unsigned long addr; void *p, *q; struct ppc_inst instr; void *buf; buf = vmalloc(PAGE_ALIGN(0x2000000 + 1)); check(buf); if (!buf) return; /* Simple case, branch to self moved a little */ p = buf; addr = (unsigned long)p; patch_branch(p, addr, 0); check(instr_is_branch_to_addr(p, addr)); q = p + 4; translate_branch(&instr, q, p); patch_instruction(q, instr); check(instr_is_branch_to_addr(q, addr)); /* Maximum negative case, move b . to addr + 32 MB */ p = buf; addr = (unsigned long)p; patch_branch(p, addr, 0); q = buf + 0x2000000; translate_branch(&instr, q, p); patch_instruction(q, instr); check(instr_is_branch_to_addr(p, addr)); check(instr_is_branch_to_addr(q, addr)); check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x4a000000))); /* Maximum positive case, move x to x - 32 MB + 4 */ p = buf + 0x2000000; addr = (unsigned long)p; patch_branch(p, addr, 0); q = buf + 4; translate_branch(&instr, q, p); patch_instruction(q, instr); check(instr_is_branch_to_addr(p, addr)); check(instr_is_branch_to_addr(q, addr)); check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x49fffffc))); /* Jump to x + 16 MB moved to x + 20 MB */ p = buf; addr = 0x1000000 + (unsigned long)buf; patch_branch(p, addr, BRANCH_SET_LINK); q = buf + 0x1400000; translate_branch(&instr, q, p); patch_instruction(q, instr); check(instr_is_branch_to_addr(p, addr)); check(instr_is_branch_to_addr(q, addr)); /* Jump to x + 16 MB moved to x - 16 MB + 4 */ p = buf + 0x1000000; addr = 0x2000000 + (unsigned long)buf; patch_branch(p, addr, 0); q = buf + 4; translate_branch(&instr, q, p); patch_instruction(q, instr); check(instr_is_branch_to_addr(p, addr)); check(instr_is_branch_to_addr(q, addr)); /* Conditional branch tests */ /* Simple case, branch to self moved a little */ p = buf; addr = (unsigned long)p; create_cond_branch(&instr, p, addr, 0); patch_instruction(p, instr); check(instr_is_branch_to_addr(p, addr)); q = buf + 4; translate_branch(&instr, q, p); patch_instruction(q, instr); check(instr_is_branch_to_addr(q, addr)); /* Maximum negative case, move b . to addr + 32 KB */ p = buf; addr = (unsigned long)p; create_cond_branch(&instr, p, addr, 0xFFFFFFFC); patch_instruction(p, instr); q = buf + 0x8000; translate_branch(&instr, q, p); patch_instruction(q, instr); check(instr_is_branch_to_addr(p, addr)); check(instr_is_branch_to_addr(q, addr)); check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x43ff8000))); /* Maximum positive case, move x to x - 32 KB + 4 */ p = buf + 0x8000; addr = (unsigned long)p; create_cond_branch(&instr, p, addr, 0xFFFFFFFC); patch_instruction(p, instr); q = buf + 4; translate_branch(&instr, q, p); patch_instruction(q, instr); check(instr_is_branch_to_addr(p, addr)); check(instr_is_branch_to_addr(q, addr)); check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x43ff7ffc))); /* Jump to x + 12 KB moved to x + 20 KB */ p = buf; addr = 0x3000 + (unsigned long)buf; create_cond_branch(&instr, p, addr, BRANCH_SET_LINK); patch_instruction(p, instr); q = buf + 0x5000; translate_branch(&instr, q, p); patch_instruction(q, instr); check(instr_is_branch_to_addr(p, addr)); check(instr_is_branch_to_addr(q, addr)); /* Jump to x + 8 KB moved to x - 8 KB + 4 */ p = buf + 0x2000; addr = 0x4000 + (unsigned long)buf; create_cond_branch(&instr, p, addr, 0); patch_instruction(p, instr); q = buf + 4; translate_branch(&instr, q, p); patch_instruction(q, instr); check(instr_is_branch_to_addr(p, addr)); check(instr_is_branch_to_addr(q, addr)); /* Free the buffer we were using */ vfree(buf); } #ifdef CONFIG_PPC64 static void __init test_prefixed_patching(void) { extern unsigned int code_patching_test1[]; extern unsigned int code_patching_test1_expected[]; extern unsigned int end_code_patching_test1[]; __patch_instruction((struct ppc_inst *)code_patching_test1, ppc_inst_prefix(OP_PREFIX << 26, 0x00000000), (struct ppc_inst *)code_patching_test1); check(!memcmp(code_patching_test1, code_patching_test1_expected, sizeof(unsigned int) * (end_code_patching_test1 - code_patching_test1))); } #else static inline void test_prefixed_patching(void) {} #endif static int __init test_code_patching(void) { printk(KERN_DEBUG "Running code patching self-tests ...\n"); test_branch_iform(); test_branch_bform(); test_create_function_call(); test_translate_branch(); test_prefixed_patching(); return 0; } late_initcall(test_code_patching); #endif /* CONFIG_CODE_PATCHING_SELFTEST */ |