1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright 2008 Michael Ellerman, IBM Corporation. 4 */ 5 6 #include <linux/kernel.h> 7 #include <linux/kprobes.h> 8 #include <linux/vmalloc.h> 9 #include <linux/init.h> 10 #include <linux/mm.h> 11 #include <linux/cpuhotplug.h> 12 #include <linux/slab.h> 13 #include <linux/uaccess.h> 14 15 #include <asm/tlbflush.h> 16 #include <asm/page.h> 17 #include <asm/code-patching.h> 18 #include <asm/setup.h> 19 #include <asm/inst.h> 20 21 static int __patch_instruction(struct ppc_inst *exec_addr, struct ppc_inst instr, 22 struct ppc_inst *patch_addr) 23 { 24 if (!ppc_inst_prefixed(instr)) 25 __put_user_asm_goto(ppc_inst_val(instr), patch_addr, failed, "stw"); 26 else 27 __put_user_asm_goto(ppc_inst_as_u64(instr), patch_addr, failed, "std"); 28 29 asm ("dcbst 0, %0; sync; icbi 0,%1; sync; isync" :: "r" (patch_addr), 30 "r" (exec_addr)); 31 32 return 0; 33 34 failed: 35 return -EFAULT; 36 } 37 38 int raw_patch_instruction(struct ppc_inst *addr, struct ppc_inst instr) 39 { 40 return __patch_instruction(addr, instr, addr); 41 } 42 43 #ifdef CONFIG_STRICT_KERNEL_RWX 44 static DEFINE_PER_CPU(struct vm_struct *, text_poke_area); 45 46 static int text_area_cpu_up(unsigned int cpu) 47 { 48 struct vm_struct *area; 49 50 area = get_vm_area(PAGE_SIZE, VM_ALLOC); 51 if (!area) { 52 WARN_ONCE(1, "Failed to create text area for cpu %d\n", 53 cpu); 54 return -1; 55 } 56 this_cpu_write(text_poke_area, area); 57 58 return 0; 59 } 60 61 static int text_area_cpu_down(unsigned int cpu) 62 { 63 free_vm_area(this_cpu_read(text_poke_area)); 64 return 0; 65 } 66 67 /* 68 * Run as a late init call. This allows all the boot time patching to be done 69 * simply by patching the code, and then we're called here prior to 70 * mark_rodata_ro(), which happens after all init calls are run. Although 71 * BUG_ON() is rude, in this case it should only happen if ENOMEM, and we judge 72 * it as being preferable to a kernel that will crash later when someone tries 73 * to use patch_instruction(). 74 */ 75 static int __init setup_text_poke_area(void) 76 { 77 BUG_ON(!cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, 78 "powerpc/text_poke:online", text_area_cpu_up, 79 text_area_cpu_down)); 80 81 return 0; 82 } 83 late_initcall(setup_text_poke_area); 84 85 /* 86 * This can be called for kernel text or a module. 87 */ 88 static int map_patch_area(void *addr, unsigned long text_poke_addr) 89 { 90 unsigned long pfn; 91 int err; 92 93 if (is_vmalloc_or_module_addr(addr)) 94 pfn = vmalloc_to_pfn(addr); 95 else 96 pfn = __pa_symbol(addr) >> PAGE_SHIFT; 97 98 err = map_kernel_page(text_poke_addr, (pfn << PAGE_SHIFT), PAGE_KERNEL); 99 100 pr_devel("Mapped addr %lx with pfn %lx:%d\n", text_poke_addr, pfn, err); 101 if (err) 102 return -1; 103 104 return 0; 105 } 106 107 static inline int unmap_patch_area(unsigned long addr) 108 { 109 pte_t *ptep; 110 pmd_t *pmdp; 111 pud_t *pudp; 112 p4d_t *p4dp; 113 pgd_t *pgdp; 114 115 pgdp = pgd_offset_k(addr); 116 if (unlikely(!pgdp)) 117 return -EINVAL; 118 119 p4dp = p4d_offset(pgdp, addr); 120 if (unlikely(!p4dp)) 121 return -EINVAL; 122 123 pudp = pud_offset(p4dp, addr); 124 if (unlikely(!pudp)) 125 return -EINVAL; 126 127 pmdp = pmd_offset(pudp, addr); 128 if (unlikely(!pmdp)) 129 return -EINVAL; 130 131 ptep = pte_offset_kernel(pmdp, addr); 132 if (unlikely(!ptep)) 133 return -EINVAL; 134 135 pr_devel("clearing mm %p, pte %p, addr %lx\n", &init_mm, ptep, addr); 136 137 /* 138 * In hash, pte_clear flushes the tlb, in radix, we have to 139 */ 140 pte_clear(&init_mm, addr, ptep); 141 flush_tlb_kernel_range(addr, addr + PAGE_SIZE); 142 143 return 0; 144 } 145 146 static int do_patch_instruction(struct ppc_inst *addr, struct ppc_inst instr) 147 { 148 int err; 149 struct ppc_inst *patch_addr = NULL; 150 unsigned long flags; 151 unsigned long text_poke_addr; 152 unsigned long kaddr = (unsigned long)addr; 153 154 /* 155 * During early early boot patch_instruction is called 156 * when text_poke_area is not ready, but we still need 157 * to allow patching. We just do the plain old patching 158 */ 159 if (!this_cpu_read(text_poke_area)) 160 return raw_patch_instruction(addr, instr); 161 162 local_irq_save(flags); 163 164 text_poke_addr = (unsigned long)__this_cpu_read(text_poke_area)->addr; 165 if (map_patch_area(addr, text_poke_addr)) { 166 err = -1; 167 goto out; 168 } 169 170 patch_addr = (struct ppc_inst *)(text_poke_addr + (kaddr & ~PAGE_MASK)); 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 static int do_patch_instruction(struct ppc_inst *addr, struct ppc_inst instr) 186 { 187 return raw_patch_instruction(addr, instr); 188 } 189 190 #endif /* CONFIG_STRICT_KERNEL_RWX */ 191 192 int patch_instruction(struct ppc_inst *addr, struct ppc_inst instr) 193 { 194 /* Make sure we aren't patching a freed init section */ 195 if (init_mem_is_free && init_section_contains(addr, 4)) { 196 pr_debug("Skipping init section patching addr: 0x%px\n", addr); 197 return 0; 198 } 199 return do_patch_instruction(addr, instr); 200 } 201 NOKPROBE_SYMBOL(patch_instruction); 202 203 int patch_branch(struct ppc_inst *addr, unsigned long target, int flags) 204 { 205 struct ppc_inst instr; 206 207 create_branch(&instr, addr, target, flags); 208 return patch_instruction(addr, instr); 209 } 210 211 bool is_offset_in_branch_range(long offset) 212 { 213 /* 214 * Powerpc branch instruction is : 215 * 216 * 0 6 30 31 217 * +---------+----------------+---+---+ 218 * | opcode | LI |AA |LK | 219 * +---------+----------------+---+---+ 220 * Where AA = 0 and LK = 0 221 * 222 * LI is a signed 24 bits integer. The real branch offset is computed 223 * by: imm32 = SignExtend(LI:'0b00', 32); 224 * 225 * So the maximum forward branch should be: 226 * (0x007fffff << 2) = 0x01fffffc = 0x1fffffc 227 * The maximum backward branch should be: 228 * (0xff800000 << 2) = 0xfe000000 = -0x2000000 229 */ 230 return (offset >= -0x2000000 && offset <= 0x1fffffc && !(offset & 0x3)); 231 } 232 233 /* 234 * Helper to check if a given instruction is a conditional branch 235 * Derived from the conditional checks in analyse_instr() 236 */ 237 bool is_conditional_branch(struct ppc_inst instr) 238 { 239 unsigned int opcode = ppc_inst_primary_opcode(instr); 240 241 if (opcode == 16) /* bc, bca, bcl, bcla */ 242 return true; 243 if (opcode == 19) { 244 switch ((ppc_inst_val(instr) >> 1) & 0x3ff) { 245 case 16: /* bclr, bclrl */ 246 case 528: /* bcctr, bcctrl */ 247 case 560: /* bctar, bctarl */ 248 return true; 249 } 250 } 251 return false; 252 } 253 NOKPROBE_SYMBOL(is_conditional_branch); 254 255 int create_branch(struct ppc_inst *instr, 256 const struct ppc_inst *addr, 257 unsigned long target, int flags) 258 { 259 long offset; 260 261 *instr = ppc_inst(0); 262 offset = target; 263 if (! (flags & BRANCH_ABSOLUTE)) 264 offset = offset - (unsigned long)addr; 265 266 /* Check we can represent the target in the instruction format */ 267 if (!is_offset_in_branch_range(offset)) 268 return 1; 269 270 /* Mask out the flags and target, so they don't step on each other. */ 271 *instr = ppc_inst(0x48000000 | (flags & 0x3) | (offset & 0x03FFFFFC)); 272 273 return 0; 274 } 275 276 int create_cond_branch(struct ppc_inst *instr, const struct ppc_inst *addr, 277 unsigned long target, int flags) 278 { 279 long offset; 280 281 offset = target; 282 if (! (flags & BRANCH_ABSOLUTE)) 283 offset = offset - (unsigned long)addr; 284 285 /* Check we can represent the target in the instruction format */ 286 if (offset < -0x8000 || offset > 0x7FFF || offset & 0x3) 287 return 1; 288 289 /* Mask out the flags and target, so they don't step on each other. */ 290 *instr = ppc_inst(0x40000000 | (flags & 0x3FF0003) | (offset & 0xFFFC)); 291 292 return 0; 293 } 294 295 static unsigned int branch_opcode(struct ppc_inst instr) 296 { 297 return ppc_inst_primary_opcode(instr) & 0x3F; 298 } 299 300 static int instr_is_branch_iform(struct ppc_inst instr) 301 { 302 return branch_opcode(instr) == 18; 303 } 304 305 static int instr_is_branch_bform(struct ppc_inst instr) 306 { 307 return branch_opcode(instr) == 16; 308 } 309 310 int instr_is_relative_branch(struct ppc_inst instr) 311 { 312 if (ppc_inst_val(instr) & BRANCH_ABSOLUTE) 313 return 0; 314 315 return instr_is_branch_iform(instr) || instr_is_branch_bform(instr); 316 } 317 318 int instr_is_relative_link_branch(struct ppc_inst instr) 319 { 320 return instr_is_relative_branch(instr) && (ppc_inst_val(instr) & BRANCH_SET_LINK); 321 } 322 323 static unsigned long branch_iform_target(const struct ppc_inst *instr) 324 { 325 signed long imm; 326 327 imm = ppc_inst_val(*instr) & 0x3FFFFFC; 328 329 /* If the top bit of the immediate value is set this is negative */ 330 if (imm & 0x2000000) 331 imm -= 0x4000000; 332 333 if ((ppc_inst_val(*instr) & BRANCH_ABSOLUTE) == 0) 334 imm += (unsigned long)instr; 335 336 return (unsigned long)imm; 337 } 338 339 static unsigned long branch_bform_target(const struct ppc_inst *instr) 340 { 341 signed long imm; 342 343 imm = ppc_inst_val(*instr) & 0xFFFC; 344 345 /* If the top bit of the immediate value is set this is negative */ 346 if (imm & 0x8000) 347 imm -= 0x10000; 348 349 if ((ppc_inst_val(*instr) & BRANCH_ABSOLUTE) == 0) 350 imm += (unsigned long)instr; 351 352 return (unsigned long)imm; 353 } 354 355 unsigned long branch_target(const struct ppc_inst *instr) 356 { 357 if (instr_is_branch_iform(ppc_inst_read(instr))) 358 return branch_iform_target(instr); 359 else if (instr_is_branch_bform(ppc_inst_read(instr))) 360 return branch_bform_target(instr); 361 362 return 0; 363 } 364 365 int instr_is_branch_to_addr(const struct ppc_inst *instr, unsigned long addr) 366 { 367 if (instr_is_branch_iform(ppc_inst_read(instr)) || 368 instr_is_branch_bform(ppc_inst_read(instr))) 369 return branch_target(instr) == addr; 370 371 return 0; 372 } 373 374 int translate_branch(struct ppc_inst *instr, const struct ppc_inst *dest, 375 const struct ppc_inst *src) 376 { 377 unsigned long target; 378 target = branch_target(src); 379 380 if (instr_is_branch_iform(ppc_inst_read(src))) 381 return create_branch(instr, dest, target, 382 ppc_inst_val(ppc_inst_read(src))); 383 else if (instr_is_branch_bform(ppc_inst_read(src))) 384 return create_cond_branch(instr, dest, target, 385 ppc_inst_val(ppc_inst_read(src))); 386 387 return 1; 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((struct ppc_inst *)(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 int err; 419 struct ppc_inst instr; 420 unsigned long addr; 421 422 addr = (unsigned long)&instr; 423 424 /* The simplest case, branch to self, no flags */ 425 check(instr_is_branch_iform(ppc_inst(0x48000000))); 426 /* All bits of target set, and flags */ 427 check(instr_is_branch_iform(ppc_inst(0x4bffffff))); 428 /* High bit of opcode set, which is wrong */ 429 check(!instr_is_branch_iform(ppc_inst(0xcbffffff))); 430 /* Middle bits of opcode set, which is wrong */ 431 check(!instr_is_branch_iform(ppc_inst(0x7bffffff))); 432 433 /* Simplest case, branch to self with link */ 434 check(instr_is_branch_iform(ppc_inst(0x48000001))); 435 /* All bits of targets set */ 436 check(instr_is_branch_iform(ppc_inst(0x4bfffffd))); 437 /* Some bits of targets set */ 438 check(instr_is_branch_iform(ppc_inst(0x4bff00fd))); 439 /* Must be a valid branch to start with */ 440 check(!instr_is_branch_iform(ppc_inst(0x7bfffffd))); 441 442 /* Absolute branch to 0x100 */ 443 instr = ppc_inst(0x48000103); 444 check(instr_is_branch_to_addr(&instr, 0x100)); 445 /* Absolute branch to 0x420fc */ 446 instr = ppc_inst(0x480420ff); 447 check(instr_is_branch_to_addr(&instr, 0x420fc)); 448 /* Maximum positive relative branch, + 20MB - 4B */ 449 instr = ppc_inst(0x49fffffc); 450 check(instr_is_branch_to_addr(&instr, addr + 0x1FFFFFC)); 451 /* Smallest negative relative branch, - 4B */ 452 instr = ppc_inst(0x4bfffffc); 453 check(instr_is_branch_to_addr(&instr, addr - 4)); 454 /* Largest negative relative branch, - 32 MB */ 455 instr = ppc_inst(0x4a000000); 456 check(instr_is_branch_to_addr(&instr, addr - 0x2000000)); 457 458 /* Branch to self, with link */ 459 err = create_branch(&instr, &instr, addr, BRANCH_SET_LINK); 460 check(instr_is_branch_to_addr(&instr, addr)); 461 462 /* Branch to self - 0x100, with link */ 463 err = create_branch(&instr, &instr, addr - 0x100, BRANCH_SET_LINK); 464 check(instr_is_branch_to_addr(&instr, addr - 0x100)); 465 466 /* Branch to self + 0x100, no link */ 467 err = create_branch(&instr, &instr, addr + 0x100, 0); 468 check(instr_is_branch_to_addr(&instr, addr + 0x100)); 469 470 /* Maximum relative negative offset, - 32 MB */ 471 err = create_branch(&instr, &instr, addr - 0x2000000, BRANCH_SET_LINK); 472 check(instr_is_branch_to_addr(&instr, addr - 0x2000000)); 473 474 /* Out of range relative negative offset, - 32 MB + 4*/ 475 err = create_branch(&instr, &instr, addr - 0x2000004, BRANCH_SET_LINK); 476 check(err); 477 478 /* Out of range relative positive offset, + 32 MB */ 479 err = create_branch(&instr, &instr, addr + 0x2000000, BRANCH_SET_LINK); 480 check(err); 481 482 /* Unaligned target */ 483 err = create_branch(&instr, &instr, addr + 3, BRANCH_SET_LINK); 484 check(err); 485 486 /* Check flags are masked correctly */ 487 err = create_branch(&instr, &instr, addr, 0xFFFFFFFC); 488 check(instr_is_branch_to_addr(&instr, addr)); 489 check(ppc_inst_equal(instr, ppc_inst(0x48000000))); 490 } 491 492 static void __init test_create_function_call(void) 493 { 494 struct ppc_inst *iptr; 495 unsigned long dest; 496 struct ppc_inst instr; 497 498 /* Check we can create a function call */ 499 iptr = (struct ppc_inst *)ppc_function_entry(test_trampoline); 500 dest = ppc_function_entry(test_create_function_call); 501 create_branch(&instr, iptr, dest, BRANCH_SET_LINK); 502 patch_instruction(iptr, instr); 503 check(instr_is_branch_to_addr(iptr, dest)); 504 } 505 506 static void __init test_branch_bform(void) 507 { 508 int err; 509 unsigned long addr; 510 struct ppc_inst *iptr, instr; 511 unsigned int flags; 512 513 iptr = &instr; 514 addr = (unsigned long)iptr; 515 516 /* The simplest case, branch to self, no flags */ 517 check(instr_is_branch_bform(ppc_inst(0x40000000))); 518 /* All bits of target set, and flags */ 519 check(instr_is_branch_bform(ppc_inst(0x43ffffff))); 520 /* High bit of opcode set, which is wrong */ 521 check(!instr_is_branch_bform(ppc_inst(0xc3ffffff))); 522 /* Middle bits of opcode set, which is wrong */ 523 check(!instr_is_branch_bform(ppc_inst(0x7bffffff))); 524 525 /* Absolute conditional branch to 0x100 */ 526 instr = ppc_inst(0x43ff0103); 527 check(instr_is_branch_to_addr(&instr, 0x100)); 528 /* Absolute conditional branch to 0x20fc */ 529 instr = ppc_inst(0x43ff20ff); 530 check(instr_is_branch_to_addr(&instr, 0x20fc)); 531 /* Maximum positive relative conditional branch, + 32 KB - 4B */ 532 instr = ppc_inst(0x43ff7ffc); 533 check(instr_is_branch_to_addr(&instr, addr + 0x7FFC)); 534 /* Smallest negative relative conditional branch, - 4B */ 535 instr = ppc_inst(0x43fffffc); 536 check(instr_is_branch_to_addr(&instr, addr - 4)); 537 /* Largest negative relative conditional branch, - 32 KB */ 538 instr = ppc_inst(0x43ff8000); 539 check(instr_is_branch_to_addr(&instr, addr - 0x8000)); 540 541 /* All condition code bits set & link */ 542 flags = 0x3ff000 | BRANCH_SET_LINK; 543 544 /* Branch to self */ 545 err = create_cond_branch(&instr, iptr, addr, flags); 546 check(instr_is_branch_to_addr(&instr, addr)); 547 548 /* Branch to self - 0x100 */ 549 err = create_cond_branch(&instr, iptr, addr - 0x100, flags); 550 check(instr_is_branch_to_addr(&instr, addr - 0x100)); 551 552 /* Branch to self + 0x100 */ 553 err = create_cond_branch(&instr, iptr, addr + 0x100, flags); 554 check(instr_is_branch_to_addr(&instr, addr + 0x100)); 555 556 /* Maximum relative negative offset, - 32 KB */ 557 err = create_cond_branch(&instr, iptr, addr - 0x8000, flags); 558 check(instr_is_branch_to_addr(&instr, addr - 0x8000)); 559 560 /* Out of range relative negative offset, - 32 KB + 4*/ 561 err = create_cond_branch(&instr, iptr, addr - 0x8004, flags); 562 check(err); 563 564 /* Out of range relative positive offset, + 32 KB */ 565 err = create_cond_branch(&instr, iptr, addr + 0x8000, flags); 566 check(err); 567 568 /* Unaligned target */ 569 err = create_cond_branch(&instr, iptr, addr + 3, flags); 570 check(err); 571 572 /* Check flags are masked correctly */ 573 err = create_cond_branch(&instr, iptr, addr, 0xFFFFFFFC); 574 check(instr_is_branch_to_addr(&instr, addr)); 575 check(ppc_inst_equal(instr, ppc_inst(0x43FF0000))); 576 } 577 578 static void __init test_translate_branch(void) 579 { 580 unsigned long addr; 581 void *p, *q; 582 struct ppc_inst instr; 583 void *buf; 584 585 buf = vmalloc(PAGE_ALIGN(0x2000000 + 1)); 586 check(buf); 587 if (!buf) 588 return; 589 590 /* Simple case, branch to self moved a little */ 591 p = buf; 592 addr = (unsigned long)p; 593 patch_branch(p, addr, 0); 594 check(instr_is_branch_to_addr(p, addr)); 595 q = p + 4; 596 translate_branch(&instr, q, p); 597 patch_instruction(q, instr); 598 check(instr_is_branch_to_addr(q, addr)); 599 600 /* Maximum negative case, move b . to addr + 32 MB */ 601 p = buf; 602 addr = (unsigned long)p; 603 patch_branch(p, addr, 0); 604 q = buf + 0x2000000; 605 translate_branch(&instr, q, p); 606 patch_instruction(q, instr); 607 check(instr_is_branch_to_addr(p, addr)); 608 check(instr_is_branch_to_addr(q, addr)); 609 check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x4a000000))); 610 611 /* Maximum positive case, move x to x - 32 MB + 4 */ 612 p = buf + 0x2000000; 613 addr = (unsigned long)p; 614 patch_branch(p, addr, 0); 615 q = buf + 4; 616 translate_branch(&instr, q, p); 617 patch_instruction(q, instr); 618 check(instr_is_branch_to_addr(p, addr)); 619 check(instr_is_branch_to_addr(q, addr)); 620 check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(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 translate_branch(&instr, q, p); 628 patch_instruction(q, instr); 629 check(instr_is_branch_to_addr(p, addr)); 630 check(instr_is_branch_to_addr(q, addr)); 631 632 /* Jump to x + 16 MB moved to x - 16 MB + 4 */ 633 p = buf + 0x1000000; 634 addr = 0x2000000 + (unsigned long)buf; 635 patch_branch(p, addr, 0); 636 q = buf + 4; 637 translate_branch(&instr, q, p); 638 patch_instruction(q, instr); 639 check(instr_is_branch_to_addr(p, addr)); 640 check(instr_is_branch_to_addr(q, addr)); 641 642 643 /* Conditional branch tests */ 644 645 /* Simple case, branch to self moved a little */ 646 p = buf; 647 addr = (unsigned long)p; 648 create_cond_branch(&instr, p, addr, 0); 649 patch_instruction(p, instr); 650 check(instr_is_branch_to_addr(p, addr)); 651 q = buf + 4; 652 translate_branch(&instr, q, p); 653 patch_instruction(q, instr); 654 check(instr_is_branch_to_addr(q, addr)); 655 656 /* Maximum negative case, move b . to addr + 32 KB */ 657 p = buf; 658 addr = (unsigned long)p; 659 create_cond_branch(&instr, p, addr, 0xFFFFFFFC); 660 patch_instruction(p, instr); 661 q = buf + 0x8000; 662 translate_branch(&instr, q, p); 663 patch_instruction(q, instr); 664 check(instr_is_branch_to_addr(p, addr)); 665 check(instr_is_branch_to_addr(q, addr)); 666 check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x43ff8000))); 667 668 /* Maximum positive case, move x to x - 32 KB + 4 */ 669 p = buf + 0x8000; 670 addr = (unsigned long)p; 671 create_cond_branch(&instr, p, addr, 0xFFFFFFFC); 672 patch_instruction(p, instr); 673 q = buf + 4; 674 translate_branch(&instr, q, p); 675 patch_instruction(q, instr); 676 check(instr_is_branch_to_addr(p, addr)); 677 check(instr_is_branch_to_addr(q, addr)); 678 check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x43ff7ffc))); 679 680 /* Jump to x + 12 KB moved to x + 20 KB */ 681 p = buf; 682 addr = 0x3000 + (unsigned long)buf; 683 create_cond_branch(&instr, p, addr, BRANCH_SET_LINK); 684 patch_instruction(p, instr); 685 q = buf + 0x5000; 686 translate_branch(&instr, q, p); 687 patch_instruction(q, instr); 688 check(instr_is_branch_to_addr(p, addr)); 689 check(instr_is_branch_to_addr(q, addr)); 690 691 /* Jump to x + 8 KB moved to x - 8 KB + 4 */ 692 p = buf + 0x2000; 693 addr = 0x4000 + (unsigned long)buf; 694 create_cond_branch(&instr, p, addr, 0); 695 patch_instruction(p, instr); 696 q = buf + 4; 697 translate_branch(&instr, q, p); 698 patch_instruction(q, instr); 699 check(instr_is_branch_to_addr(p, addr)); 700 check(instr_is_branch_to_addr(q, addr)); 701 702 /* Free the buffer we were using */ 703 vfree(buf); 704 } 705 706 #ifdef CONFIG_PPC64 707 static void __init test_prefixed_patching(void) 708 { 709 extern unsigned int code_patching_test1[]; 710 extern unsigned int code_patching_test1_expected[]; 711 extern unsigned int end_code_patching_test1[]; 712 713 __patch_instruction((struct ppc_inst *)code_patching_test1, 714 ppc_inst_prefix(OP_PREFIX << 26, 0x00000000), 715 (struct ppc_inst *)code_patching_test1); 716 717 check(!memcmp(code_patching_test1, 718 code_patching_test1_expected, 719 sizeof(unsigned int) * 720 (end_code_patching_test1 - code_patching_test1))); 721 } 722 #else 723 static inline void test_prefixed_patching(void) {} 724 #endif 725 726 static int __init test_code_patching(void) 727 { 728 printk(KERN_DEBUG "Running code patching self-tests ...\n"); 729 730 test_branch_iform(); 731 test_branch_bform(); 732 test_create_function_call(); 733 test_translate_branch(); 734 test_prefixed_patching(); 735 736 return 0; 737 } 738 late_initcall(test_code_patching); 739 740 #endif /* CONFIG_CODE_PATCHING_SELFTEST */ 741