1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Kernel support for the ptrace() and syscall tracing interfaces. 4 * 5 * Copyright (C) 2000 Hewlett-Packard Co, Linuxcare Inc. 6 * Copyright (C) 2000 Matthew Wilcox <matthew@wil.cx> 7 * Copyright (C) 2000 David Huggins-Daines <dhd@debian.org> 8 * Copyright (C) 2008-2016 Helge Deller <deller@gmx.de> 9 */ 10 11 #include <linux/kernel.h> 12 #include <linux/sched.h> 13 #include <linux/mm.h> 14 #include <linux/smp.h> 15 #include <linux/elf.h> 16 #include <linux/errno.h> 17 #include <linux/ptrace.h> 18 #include <linux/user.h> 19 #include <linux/personality.h> 20 #include <linux/regset.h> 21 #include <linux/security.h> 22 #include <linux/seccomp.h> 23 #include <linux/compat.h> 24 #include <linux/signal.h> 25 #include <linux/audit.h> 26 27 #include <linux/uaccess.h> 28 #include <asm/processor.h> 29 #include <asm/asm-offsets.h> 30 31 /* PSW bits we allow the debugger to modify */ 32 #define USER_PSW_BITS (PSW_N | PSW_B | PSW_V | PSW_CB) 33 34 #define CREATE_TRACE_POINTS 35 #include <trace/events/syscalls.h> 36 37 /* 38 * These are our native regset flavors. 39 */ 40 enum parisc_regset { 41 REGSET_GENERAL, 42 REGSET_FP 43 }; 44 45 /* 46 * Called by kernel/ptrace.c when detaching.. 47 * 48 * Make sure single step bits etc are not set. 49 */ 50 void ptrace_disable(struct task_struct *task) 51 { 52 clear_tsk_thread_flag(task, TIF_SINGLESTEP); 53 clear_tsk_thread_flag(task, TIF_BLOCKSTEP); 54 55 /* make sure the trap bits are not set */ 56 pa_psw(task)->r = 0; 57 pa_psw(task)->t = 0; 58 pa_psw(task)->h = 0; 59 pa_psw(task)->l = 0; 60 } 61 62 /* 63 * The following functions are called by ptrace_resume() when 64 * enabling or disabling single/block tracing. 65 */ 66 void user_disable_single_step(struct task_struct *task) 67 { 68 ptrace_disable(task); 69 } 70 71 void user_enable_single_step(struct task_struct *task) 72 { 73 clear_tsk_thread_flag(task, TIF_BLOCKSTEP); 74 set_tsk_thread_flag(task, TIF_SINGLESTEP); 75 76 if (pa_psw(task)->n) { 77 /* Nullified, just crank over the queue. */ 78 task_regs(task)->iaoq[0] = task_regs(task)->iaoq[1]; 79 task_regs(task)->iasq[0] = task_regs(task)->iasq[1]; 80 task_regs(task)->iaoq[1] = task_regs(task)->iaoq[0] + 4; 81 pa_psw(task)->n = 0; 82 pa_psw(task)->x = 0; 83 pa_psw(task)->y = 0; 84 pa_psw(task)->z = 0; 85 pa_psw(task)->b = 0; 86 ptrace_disable(task); 87 /* Don't wake up the task, but let the 88 parent know something happened. */ 89 force_sig_fault_to_task(SIGTRAP, TRAP_TRACE, 90 (void __user *) (task_regs(task)->iaoq[0] & ~3), 91 task); 92 /* notify_parent(task, SIGCHLD); */ 93 return; 94 } 95 96 /* Enable recovery counter traps. The recovery counter 97 * itself will be set to zero on a task switch. If the 98 * task is suspended on a syscall then the syscall return 99 * path will overwrite the recovery counter with a suitable 100 * value such that it traps once back in user space. We 101 * disable interrupts in the tasks PSW here also, to avoid 102 * interrupts while the recovery counter is decrementing. 103 */ 104 pa_psw(task)->r = 1; 105 pa_psw(task)->t = 0; 106 pa_psw(task)->h = 0; 107 pa_psw(task)->l = 0; 108 } 109 110 void user_enable_block_step(struct task_struct *task) 111 { 112 clear_tsk_thread_flag(task, TIF_SINGLESTEP); 113 set_tsk_thread_flag(task, TIF_BLOCKSTEP); 114 115 /* Enable taken branch trap. */ 116 pa_psw(task)->r = 0; 117 pa_psw(task)->t = 1; 118 pa_psw(task)->h = 0; 119 pa_psw(task)->l = 0; 120 } 121 122 long arch_ptrace(struct task_struct *child, long request, 123 unsigned long addr, unsigned long data) 124 { 125 unsigned long __user *datap = (unsigned long __user *)data; 126 unsigned long tmp; 127 long ret = -EIO; 128 129 unsigned long user_regs_struct_size = sizeof(struct user_regs_struct); 130 #ifdef CONFIG_64BIT 131 if (is_compat_task()) 132 user_regs_struct_size /= 2; 133 #endif 134 135 switch (request) { 136 137 /* Read the word at location addr in the USER area. For ptraced 138 processes, the kernel saves all regs on a syscall. */ 139 case PTRACE_PEEKUSR: 140 if ((addr & (sizeof(unsigned long)-1)) || 141 addr >= sizeof(struct pt_regs)) 142 break; 143 tmp = *(unsigned long *) ((char *) task_regs(child) + addr); 144 ret = put_user(tmp, datap); 145 break; 146 147 /* Write the word at location addr in the USER area. This will need 148 to change when the kernel no longer saves all regs on a syscall. 149 FIXME. There is a problem at the moment in that r3-r18 are only 150 saved if the process is ptraced on syscall entry, and even then 151 those values are overwritten by actual register values on syscall 152 exit. */ 153 case PTRACE_POKEUSR: 154 /* Some register values written here may be ignored in 155 * entry.S:syscall_restore_rfi; e.g. iaoq is written with 156 * r31/r31+4, and not with the values in pt_regs. 157 */ 158 if (addr == PT_PSW) { 159 /* Allow writing to Nullify, Divide-step-correction, 160 * and carry/borrow bits. 161 * BEWARE, if you set N, and then single step, it won't 162 * stop on the nullified instruction. 163 */ 164 data &= USER_PSW_BITS; 165 task_regs(child)->gr[0] &= ~USER_PSW_BITS; 166 task_regs(child)->gr[0] |= data; 167 ret = 0; 168 break; 169 } 170 171 if ((addr & (sizeof(unsigned long)-1)) || 172 addr >= sizeof(struct pt_regs)) 173 break; 174 if (addr == PT_IAOQ0 || addr == PT_IAOQ1) { 175 data |= PRIV_USER; /* ensure userspace privilege */ 176 } 177 if ((addr >= PT_GR1 && addr <= PT_GR31) || 178 addr == PT_IAOQ0 || addr == PT_IAOQ1 || 179 (addr >= PT_FR0 && addr <= PT_FR31 + 4) || 180 addr == PT_SAR) { 181 *(unsigned long *) ((char *) task_regs(child) + addr) = data; 182 ret = 0; 183 } 184 break; 185 186 case PTRACE_GETREGS: /* Get all gp regs from the child. */ 187 return copy_regset_to_user(child, 188 task_user_regset_view(current), 189 REGSET_GENERAL, 190 0, user_regs_struct_size, 191 datap); 192 193 case PTRACE_SETREGS: /* Set all gp regs in the child. */ 194 return copy_regset_from_user(child, 195 task_user_regset_view(current), 196 REGSET_GENERAL, 197 0, user_regs_struct_size, 198 datap); 199 200 case PTRACE_GETFPREGS: /* Get the child FPU state. */ 201 return copy_regset_to_user(child, 202 task_user_regset_view(current), 203 REGSET_FP, 204 0, sizeof(struct user_fp_struct), 205 datap); 206 207 case PTRACE_SETFPREGS: /* Set the child FPU state. */ 208 return copy_regset_from_user(child, 209 task_user_regset_view(current), 210 REGSET_FP, 211 0, sizeof(struct user_fp_struct), 212 datap); 213 214 default: 215 ret = ptrace_request(child, request, addr, data); 216 break; 217 } 218 219 return ret; 220 } 221 222 223 #ifdef CONFIG_COMPAT 224 225 /* This function is needed to translate 32 bit pt_regs offsets in to 226 * 64 bit pt_regs offsets. For example, a 32 bit gdb under a 64 bit kernel 227 * will request offset 12 if it wants gr3, but the lower 32 bits of 228 * the 64 bit kernels view of gr3 will be at offset 28 (3*8 + 4). 229 * This code relies on a 32 bit pt_regs being comprised of 32 bit values 230 * except for the fp registers which (a) are 64 bits, and (b) follow 231 * the gr registers at the start of pt_regs. The 32 bit pt_regs should 232 * be half the size of the 64 bit pt_regs, plus 32*4 to allow for fr[] 233 * being 64 bit in both cases. 234 */ 235 236 static compat_ulong_t translate_usr_offset(compat_ulong_t offset) 237 { 238 compat_ulong_t pos; 239 240 if (offset < 32*4) /* gr[0..31] */ 241 pos = offset * 2 + 4; 242 else if (offset < 32*4+32*8) /* fr[0] ... fr[31] */ 243 pos = (offset - 32*4) + PT_FR0; 244 else if (offset < sizeof(struct pt_regs)/2 + 32*4) /* sr[0] ... ipsw */ 245 pos = (offset - 32*4 - 32*8) * 2 + PT_SR0 + 4; 246 else 247 pos = sizeof(struct pt_regs); 248 249 return pos; 250 } 251 252 long compat_arch_ptrace(struct task_struct *child, compat_long_t request, 253 compat_ulong_t addr, compat_ulong_t data) 254 { 255 compat_uint_t tmp; 256 long ret = -EIO; 257 258 switch (request) { 259 260 case PTRACE_PEEKUSR: 261 if (addr & (sizeof(compat_uint_t)-1)) 262 break; 263 addr = translate_usr_offset(addr); 264 if (addr >= sizeof(struct pt_regs)) 265 break; 266 267 tmp = *(compat_uint_t *) ((char *) task_regs(child) + addr); 268 ret = put_user(tmp, (compat_uint_t *) (unsigned long) data); 269 break; 270 271 /* Write the word at location addr in the USER area. This will need 272 to change when the kernel no longer saves all regs on a syscall. 273 FIXME. There is a problem at the moment in that r3-r18 are only 274 saved if the process is ptraced on syscall entry, and even then 275 those values are overwritten by actual register values on syscall 276 exit. */ 277 case PTRACE_POKEUSR: 278 /* Some register values written here may be ignored in 279 * entry.S:syscall_restore_rfi; e.g. iaoq is written with 280 * r31/r31+4, and not with the values in pt_regs. 281 */ 282 if (addr == PT_PSW) { 283 /* Since PT_PSW==0, it is valid for 32 bit processes 284 * under 64 bit kernels as well. 285 */ 286 ret = arch_ptrace(child, request, addr, data); 287 } else { 288 if (addr & (sizeof(compat_uint_t)-1)) 289 break; 290 addr = translate_usr_offset(addr); 291 if (addr >= sizeof(struct pt_regs)) 292 break; 293 if (addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4) { 294 data |= PRIV_USER; /* ensure userspace privilege */ 295 } 296 if (addr >= PT_FR0 && addr <= PT_FR31 + 4) { 297 /* Special case, fp regs are 64 bits anyway */ 298 *(__u32 *) ((char *) task_regs(child) + addr) = data; 299 ret = 0; 300 } 301 else if ((addr >= PT_GR1+4 && addr <= PT_GR31+4) || 302 addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4 || 303 addr == PT_SAR+4) { 304 /* Zero the top 32 bits */ 305 *(__u32 *) ((char *) task_regs(child) + addr - 4) = 0; 306 *(__u32 *) ((char *) task_regs(child) + addr) = data; 307 ret = 0; 308 } 309 } 310 break; 311 case PTRACE_GETREGS: 312 case PTRACE_SETREGS: 313 case PTRACE_GETFPREGS: 314 case PTRACE_SETFPREGS: 315 return arch_ptrace(child, request, addr, data); 316 317 default: 318 ret = compat_ptrace_request(child, request, addr, data); 319 break; 320 } 321 322 return ret; 323 } 324 #endif 325 326 long do_syscall_trace_enter(struct pt_regs *regs) 327 { 328 if (test_thread_flag(TIF_SYSCALL_TRACE)) { 329 int rc = ptrace_report_syscall_entry(regs); 330 331 /* 332 * As tracesys_next does not set %r28 to -ENOSYS 333 * when %r20 is set to -1, initialize it here. 334 */ 335 regs->gr[28] = -ENOSYS; 336 337 if (rc) { 338 /* 339 * A nonzero return code from 340 * ptrace_report_syscall_entry() tells us 341 * to prevent the syscall execution. Skip 342 * the syscall call and the syscall restart handling. 343 * 344 * Note that the tracer may also just change 345 * regs->gr[20] to an invalid syscall number, 346 * that is handled by tracesys_next. 347 */ 348 regs->gr[20] = -1UL; 349 return -1; 350 } 351 } 352 353 /* Do the secure computing check after ptrace. */ 354 if (secure_computing() == -1) 355 return -1; 356 357 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS 358 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) 359 trace_sys_enter(regs, regs->gr[20]); 360 #endif 361 362 #ifdef CONFIG_64BIT 363 if (!is_compat_task()) 364 audit_syscall_entry(regs->gr[20], regs->gr[26], regs->gr[25], 365 regs->gr[24], regs->gr[23]); 366 else 367 #endif 368 audit_syscall_entry(regs->gr[20] & 0xffffffff, 369 regs->gr[26] & 0xffffffff, 370 regs->gr[25] & 0xffffffff, 371 regs->gr[24] & 0xffffffff, 372 regs->gr[23] & 0xffffffff); 373 374 /* 375 * Sign extend the syscall number to 64bit since it may have been 376 * modified by a compat ptrace call 377 */ 378 return (int) ((u32) regs->gr[20]); 379 } 380 381 void do_syscall_trace_exit(struct pt_regs *regs) 382 { 383 int stepping = test_thread_flag(TIF_SINGLESTEP) || 384 test_thread_flag(TIF_BLOCKSTEP); 385 386 audit_syscall_exit(regs); 387 388 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS 389 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) 390 trace_sys_exit(regs, regs->gr[20]); 391 #endif 392 393 if (stepping || test_thread_flag(TIF_SYSCALL_TRACE)) 394 ptrace_report_syscall_exit(regs, stepping); 395 } 396 397 398 /* 399 * regset functions. 400 */ 401 402 static int fpr_get(struct task_struct *target, 403 const struct user_regset *regset, 404 struct membuf to) 405 { 406 struct pt_regs *regs = task_regs(target); 407 408 return membuf_write(&to, regs->fr, ELF_NFPREG * sizeof(__u64)); 409 } 410 411 static int fpr_set(struct task_struct *target, 412 const struct user_regset *regset, 413 unsigned int pos, unsigned int count, 414 const void *kbuf, const void __user *ubuf) 415 { 416 struct pt_regs *regs = task_regs(target); 417 const __u64 *k = kbuf; 418 const __u64 __user *u = ubuf; 419 __u64 reg; 420 421 pos /= sizeof(reg); 422 count /= sizeof(reg); 423 424 if (kbuf) 425 for (; count > 0 && pos < ELF_NFPREG; --count) 426 regs->fr[pos++] = *k++; 427 else 428 for (; count > 0 && pos < ELF_NFPREG; --count) { 429 if (__get_user(reg, u++)) 430 return -EFAULT; 431 regs->fr[pos++] = reg; 432 } 433 434 kbuf = k; 435 ubuf = u; 436 pos *= sizeof(reg); 437 count *= sizeof(reg); 438 user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 439 ELF_NFPREG * sizeof(reg), -1); 440 return 0; 441 } 442 443 #define RI(reg) (offsetof(struct user_regs_struct,reg) / sizeof(long)) 444 445 static unsigned long get_reg(struct pt_regs *regs, int num) 446 { 447 switch (num) { 448 case RI(gr[0]) ... RI(gr[31]): return regs->gr[num - RI(gr[0])]; 449 case RI(sr[0]) ... RI(sr[7]): return regs->sr[num - RI(sr[0])]; 450 case RI(iasq[0]): return regs->iasq[0]; 451 case RI(iasq[1]): return regs->iasq[1]; 452 case RI(iaoq[0]): return regs->iaoq[0]; 453 case RI(iaoq[1]): return regs->iaoq[1]; 454 case RI(sar): return regs->sar; 455 case RI(iir): return regs->iir; 456 case RI(isr): return regs->isr; 457 case RI(ior): return regs->ior; 458 case RI(ipsw): return regs->ipsw; 459 case RI(cr27): return regs->cr27; 460 case RI(cr0): return mfctl(0); 461 case RI(cr24): return mfctl(24); 462 case RI(cr25): return mfctl(25); 463 case RI(cr26): return mfctl(26); 464 case RI(cr28): return mfctl(28); 465 case RI(cr29): return mfctl(29); 466 case RI(cr30): return mfctl(30); 467 case RI(cr31): return mfctl(31); 468 case RI(cr8): return mfctl(8); 469 case RI(cr9): return mfctl(9); 470 case RI(cr12): return mfctl(12); 471 case RI(cr13): return mfctl(13); 472 case RI(cr10): return mfctl(10); 473 case RI(cr15): return mfctl(15); 474 default: return 0; 475 } 476 } 477 478 static void set_reg(struct pt_regs *regs, int num, unsigned long val) 479 { 480 switch (num) { 481 case RI(gr[0]): /* 482 * PSW is in gr[0]. 483 * Allow writing to Nullify, Divide-step-correction, 484 * and carry/borrow bits. 485 * BEWARE, if you set N, and then single step, it won't 486 * stop on the nullified instruction. 487 */ 488 val &= USER_PSW_BITS; 489 regs->gr[0] &= ~USER_PSW_BITS; 490 regs->gr[0] |= val; 491 return; 492 case RI(gr[1]) ... RI(gr[31]): 493 regs->gr[num - RI(gr[0])] = val; 494 return; 495 case RI(iaoq[0]): 496 case RI(iaoq[1]): 497 /* set 2 lowest bits to ensure userspace privilege: */ 498 regs->iaoq[num - RI(iaoq[0])] = val | PRIV_USER; 499 return; 500 case RI(sar): regs->sar = val; 501 return; 502 default: return; 503 #if 0 504 /* do not allow to change any of the following registers (yet) */ 505 case RI(sr[0]) ... RI(sr[7]): return regs->sr[num - RI(sr[0])]; 506 case RI(iasq[0]): return regs->iasq[0]; 507 case RI(iasq[1]): return regs->iasq[1]; 508 case RI(iir): return regs->iir; 509 case RI(isr): return regs->isr; 510 case RI(ior): return regs->ior; 511 case RI(ipsw): return regs->ipsw; 512 case RI(cr27): return regs->cr27; 513 case cr0, cr24, cr25, cr26, cr27, cr28, cr29, cr30, cr31; 514 case cr8, cr9, cr12, cr13, cr10, cr15; 515 #endif 516 } 517 } 518 519 static int gpr_get(struct task_struct *target, 520 const struct user_regset *regset, 521 struct membuf to) 522 { 523 struct pt_regs *regs = task_regs(target); 524 unsigned int pos; 525 526 for (pos = 0; pos < ELF_NGREG; pos++) 527 membuf_store(&to, get_reg(regs, pos)); 528 return 0; 529 } 530 531 static int gpr_set(struct task_struct *target, 532 const struct user_regset *regset, 533 unsigned int pos, unsigned int count, 534 const void *kbuf, const void __user *ubuf) 535 { 536 struct pt_regs *regs = task_regs(target); 537 const unsigned long *k = kbuf; 538 const unsigned long __user *u = ubuf; 539 unsigned long reg; 540 541 pos /= sizeof(reg); 542 count /= sizeof(reg); 543 544 if (kbuf) 545 for (; count > 0 && pos < ELF_NGREG; --count) 546 set_reg(regs, pos++, *k++); 547 else 548 for (; count > 0 && pos < ELF_NGREG; --count) { 549 if (__get_user(reg, u++)) 550 return -EFAULT; 551 set_reg(regs, pos++, reg); 552 } 553 554 kbuf = k; 555 ubuf = u; 556 pos *= sizeof(reg); 557 count *= sizeof(reg); 558 user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 559 ELF_NGREG * sizeof(reg), -1); 560 return 0; 561 } 562 563 static const struct user_regset native_regsets[] = { 564 [REGSET_GENERAL] = { 565 .core_note_type = NT_PRSTATUS, .n = ELF_NGREG, 566 .size = sizeof(long), .align = sizeof(long), 567 .regset_get = gpr_get, .set = gpr_set 568 }, 569 [REGSET_FP] = { 570 .core_note_type = NT_PRFPREG, .n = ELF_NFPREG, 571 .size = sizeof(__u64), .align = sizeof(__u64), 572 .regset_get = fpr_get, .set = fpr_set 573 } 574 }; 575 576 static const struct user_regset_view user_parisc_native_view = { 577 .name = "parisc", .e_machine = ELF_ARCH, .ei_osabi = ELFOSABI_LINUX, 578 .regsets = native_regsets, .n = ARRAY_SIZE(native_regsets) 579 }; 580 581 #ifdef CONFIG_64BIT 582 static int gpr32_get(struct task_struct *target, 583 const struct user_regset *regset, 584 struct membuf to) 585 { 586 struct pt_regs *regs = task_regs(target); 587 unsigned int pos; 588 589 for (pos = 0; pos < ELF_NGREG; pos++) 590 membuf_store(&to, (compat_ulong_t)get_reg(regs, pos)); 591 592 return 0; 593 } 594 595 static int gpr32_set(struct task_struct *target, 596 const struct user_regset *regset, 597 unsigned int pos, unsigned int count, 598 const void *kbuf, const void __user *ubuf) 599 { 600 struct pt_regs *regs = task_regs(target); 601 const compat_ulong_t *k = kbuf; 602 const compat_ulong_t __user *u = ubuf; 603 compat_ulong_t reg; 604 605 pos /= sizeof(reg); 606 count /= sizeof(reg); 607 608 if (kbuf) 609 for (; count > 0 && pos < ELF_NGREG; --count) 610 set_reg(regs, pos++, *k++); 611 else 612 for (; count > 0 && pos < ELF_NGREG; --count) { 613 if (__get_user(reg, u++)) 614 return -EFAULT; 615 set_reg(regs, pos++, reg); 616 } 617 618 kbuf = k; 619 ubuf = u; 620 pos *= sizeof(reg); 621 count *= sizeof(reg); 622 user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 623 ELF_NGREG * sizeof(reg), -1); 624 return 0; 625 } 626 627 /* 628 * These are the regset flavors matching the 32bit native set. 629 */ 630 static const struct user_regset compat_regsets[] = { 631 [REGSET_GENERAL] = { 632 .core_note_type = NT_PRSTATUS, .n = ELF_NGREG, 633 .size = sizeof(compat_long_t), .align = sizeof(compat_long_t), 634 .regset_get = gpr32_get, .set = gpr32_set 635 }, 636 [REGSET_FP] = { 637 .core_note_type = NT_PRFPREG, .n = ELF_NFPREG, 638 .size = sizeof(__u64), .align = sizeof(__u64), 639 .regset_get = fpr_get, .set = fpr_set 640 } 641 }; 642 643 static const struct user_regset_view user_parisc_compat_view = { 644 .name = "parisc", .e_machine = EM_PARISC, .ei_osabi = ELFOSABI_LINUX, 645 .regsets = compat_regsets, .n = ARRAY_SIZE(compat_regsets) 646 }; 647 #endif /* CONFIG_64BIT */ 648 649 const struct user_regset_view *task_user_regset_view(struct task_struct *task) 650 { 651 BUILD_BUG_ON(sizeof(struct user_regs_struct)/sizeof(long) != ELF_NGREG); 652 BUILD_BUG_ON(sizeof(struct user_fp_struct)/sizeof(__u64) != ELF_NFPREG); 653 #ifdef CONFIG_64BIT 654 if (is_compat_task()) 655 return &user_parisc_compat_view; 656 #endif 657 return &user_parisc_native_view; 658 } 659 660 661 /* HAVE_REGS_AND_STACK_ACCESS_API feature */ 662 663 struct pt_regs_offset { 664 const char *name; 665 int offset; 666 }; 667 668 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)} 669 #define REG_OFFSET_INDEX(r,i) {.name = #r#i, .offset = offsetof(struct pt_regs, r[i])} 670 #define REG_OFFSET_END {.name = NULL, .offset = 0} 671 672 static const struct pt_regs_offset regoffset_table[] = { 673 REG_OFFSET_INDEX(gr,0), 674 REG_OFFSET_INDEX(gr,1), 675 REG_OFFSET_INDEX(gr,2), 676 REG_OFFSET_INDEX(gr,3), 677 REG_OFFSET_INDEX(gr,4), 678 REG_OFFSET_INDEX(gr,5), 679 REG_OFFSET_INDEX(gr,6), 680 REG_OFFSET_INDEX(gr,7), 681 REG_OFFSET_INDEX(gr,8), 682 REG_OFFSET_INDEX(gr,9), 683 REG_OFFSET_INDEX(gr,10), 684 REG_OFFSET_INDEX(gr,11), 685 REG_OFFSET_INDEX(gr,12), 686 REG_OFFSET_INDEX(gr,13), 687 REG_OFFSET_INDEX(gr,14), 688 REG_OFFSET_INDEX(gr,15), 689 REG_OFFSET_INDEX(gr,16), 690 REG_OFFSET_INDEX(gr,17), 691 REG_OFFSET_INDEX(gr,18), 692 REG_OFFSET_INDEX(gr,19), 693 REG_OFFSET_INDEX(gr,20), 694 REG_OFFSET_INDEX(gr,21), 695 REG_OFFSET_INDEX(gr,22), 696 REG_OFFSET_INDEX(gr,23), 697 REG_OFFSET_INDEX(gr,24), 698 REG_OFFSET_INDEX(gr,25), 699 REG_OFFSET_INDEX(gr,26), 700 REG_OFFSET_INDEX(gr,27), 701 REG_OFFSET_INDEX(gr,28), 702 REG_OFFSET_INDEX(gr,29), 703 REG_OFFSET_INDEX(gr,30), 704 REG_OFFSET_INDEX(gr,31), 705 REG_OFFSET_INDEX(sr,0), 706 REG_OFFSET_INDEX(sr,1), 707 REG_OFFSET_INDEX(sr,2), 708 REG_OFFSET_INDEX(sr,3), 709 REG_OFFSET_INDEX(sr,4), 710 REG_OFFSET_INDEX(sr,5), 711 REG_OFFSET_INDEX(sr,6), 712 REG_OFFSET_INDEX(sr,7), 713 REG_OFFSET_INDEX(iasq,0), 714 REG_OFFSET_INDEX(iasq,1), 715 REG_OFFSET_INDEX(iaoq,0), 716 REG_OFFSET_INDEX(iaoq,1), 717 REG_OFFSET_NAME(cr27), 718 REG_OFFSET_NAME(ksp), 719 REG_OFFSET_NAME(kpc), 720 REG_OFFSET_NAME(sar), 721 REG_OFFSET_NAME(iir), 722 REG_OFFSET_NAME(isr), 723 REG_OFFSET_NAME(ior), 724 REG_OFFSET_NAME(ipsw), 725 REG_OFFSET_END, 726 }; 727 728 /** 729 * regs_query_register_offset() - query register offset from its name 730 * @name: the name of a register 731 * 732 * regs_query_register_offset() returns the offset of a register in struct 733 * pt_regs from its name. If the name is invalid, this returns -EINVAL; 734 */ 735 int regs_query_register_offset(const char *name) 736 { 737 const struct pt_regs_offset *roff; 738 for (roff = regoffset_table; roff->name != NULL; roff++) 739 if (!strcmp(roff->name, name)) 740 return roff->offset; 741 return -EINVAL; 742 } 743 744 /** 745 * regs_query_register_name() - query register name from its offset 746 * @offset: the offset of a register in struct pt_regs. 747 * 748 * regs_query_register_name() returns the name of a register from its 749 * offset in struct pt_regs. If the @offset is invalid, this returns NULL; 750 */ 751 const char *regs_query_register_name(unsigned int offset) 752 { 753 const struct pt_regs_offset *roff; 754 for (roff = regoffset_table; roff->name != NULL; roff++) 755 if (roff->offset == offset) 756 return roff->name; 757 return NULL; 758 } 759 760 /** 761 * regs_within_kernel_stack() - check the address in the stack 762 * @regs: pt_regs which contains kernel stack pointer. 763 * @addr: address which is checked. 764 * 765 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s). 766 * If @addr is within the kernel stack, it returns true. If not, returns false. 767 */ 768 int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr) 769 { 770 return ((addr & ~(THREAD_SIZE - 1)) == 771 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))); 772 } 773 774 /** 775 * regs_get_kernel_stack_nth() - get Nth entry of the stack 776 * @regs: pt_regs which contains kernel stack pointer. 777 * @n: stack entry number. 778 * 779 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which 780 * is specified by @regs. If the @n th entry is NOT in the kernel stack, 781 * this returns 0. 782 */ 783 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n) 784 { 785 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs); 786 787 addr -= n; 788 789 if (!regs_within_kernel_stack(regs, (unsigned long)addr)) 790 return 0; 791 792 return *addr; 793 } 794