1 /* 2 * This file is subject to the terms and conditions of the GNU General Public 3 * License. See the file "COPYING" in the main directory of this archive 4 * for more details. 5 * 6 * Copyright (C) 1992 Ross Biro 7 * Copyright (C) Linus Torvalds 8 * Copyright (C) 1994, 95, 96, 97, 98, 2000 Ralf Baechle 9 * Copyright (C) 1996 David S. Miller 10 * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com 11 * Copyright (C) 1999 MIPS Technologies, Inc. 12 * Copyright (C) 2000 Ulf Carlsson 13 * 14 * At this time Linux/MIPS64 only supports syscall tracing, even for 32-bit 15 * binaries. 16 */ 17 #include <linux/compiler.h> 18 #include <linux/kernel.h> 19 #include <linux/sched.h> 20 #include <linux/mm.h> 21 #include <linux/errno.h> 22 #include <linux/ptrace.h> 23 #include <linux/smp.h> 24 #include <linux/user.h> 25 #include <linux/security.h> 26 #include <linux/audit.h> 27 #include <linux/seccomp.h> 28 29 #include <asm/byteorder.h> 30 #include <asm/cpu.h> 31 #include <asm/dsp.h> 32 #include <asm/fpu.h> 33 #include <asm/mipsregs.h> 34 #include <asm/mipsmtregs.h> 35 #include <asm/pgtable.h> 36 #include <asm/page.h> 37 #include <asm/system.h> 38 #include <asm/uaccess.h> 39 #include <asm/bootinfo.h> 40 #include <asm/reg.h> 41 42 /* 43 * Called by kernel/ptrace.c when detaching.. 44 * 45 * Make sure single step bits etc are not set. 46 */ 47 void ptrace_disable(struct task_struct *child) 48 { 49 /* Don't load the watchpoint registers for the ex-child. */ 50 clear_tsk_thread_flag(child, TIF_LOAD_WATCH); 51 } 52 53 /* 54 * Read a general register set. We always use the 64-bit format, even 55 * for 32-bit kernels and for 32-bit processes on a 64-bit kernel. 56 * Registers are sign extended to fill the available space. 57 */ 58 int ptrace_getregs(struct task_struct *child, __s64 __user *data) 59 { 60 struct pt_regs *regs; 61 int i; 62 63 if (!access_ok(VERIFY_WRITE, data, 38 * 8)) 64 return -EIO; 65 66 regs = task_pt_regs(child); 67 68 for (i = 0; i < 32; i++) 69 __put_user((long)regs->regs[i], data + i); 70 __put_user((long)regs->lo, data + EF_LO - EF_R0); 71 __put_user((long)regs->hi, data + EF_HI - EF_R0); 72 __put_user((long)regs->cp0_epc, data + EF_CP0_EPC - EF_R0); 73 __put_user((long)regs->cp0_badvaddr, data + EF_CP0_BADVADDR - EF_R0); 74 __put_user((long)regs->cp0_status, data + EF_CP0_STATUS - EF_R0); 75 __put_user((long)regs->cp0_cause, data + EF_CP0_CAUSE - EF_R0); 76 77 return 0; 78 } 79 80 /* 81 * Write a general register set. As for PTRACE_GETREGS, we always use 82 * the 64-bit format. On a 32-bit kernel only the lower order half 83 * (according to endianness) will be used. 84 */ 85 int ptrace_setregs(struct task_struct *child, __s64 __user *data) 86 { 87 struct pt_regs *regs; 88 int i; 89 90 if (!access_ok(VERIFY_READ, data, 38 * 8)) 91 return -EIO; 92 93 regs = task_pt_regs(child); 94 95 for (i = 0; i < 32; i++) 96 __get_user(regs->regs[i], data + i); 97 __get_user(regs->lo, data + EF_LO - EF_R0); 98 __get_user(regs->hi, data + EF_HI - EF_R0); 99 __get_user(regs->cp0_epc, data + EF_CP0_EPC - EF_R0); 100 101 /* badvaddr, status, and cause may not be written. */ 102 103 return 0; 104 } 105 106 int ptrace_getfpregs(struct task_struct *child, __u32 __user *data) 107 { 108 int i; 109 unsigned int tmp; 110 111 if (!access_ok(VERIFY_WRITE, data, 33 * 8)) 112 return -EIO; 113 114 if (tsk_used_math(child)) { 115 fpureg_t *fregs = get_fpu_regs(child); 116 for (i = 0; i < 32; i++) 117 __put_user(fregs[i], i + (__u64 __user *) data); 118 } else { 119 for (i = 0; i < 32; i++) 120 __put_user((__u64) -1, i + (__u64 __user *) data); 121 } 122 123 __put_user(child->thread.fpu.fcr31, data + 64); 124 125 preempt_disable(); 126 if (cpu_has_fpu) { 127 unsigned int flags; 128 129 if (cpu_has_mipsmt) { 130 unsigned int vpflags = dvpe(); 131 flags = read_c0_status(); 132 __enable_fpu(); 133 __asm__ __volatile__("cfc1\t%0,$0" : "=r" (tmp)); 134 write_c0_status(flags); 135 evpe(vpflags); 136 } else { 137 flags = read_c0_status(); 138 __enable_fpu(); 139 __asm__ __volatile__("cfc1\t%0,$0" : "=r" (tmp)); 140 write_c0_status(flags); 141 } 142 } else { 143 tmp = 0; 144 } 145 preempt_enable(); 146 __put_user(tmp, data + 65); 147 148 return 0; 149 } 150 151 int ptrace_setfpregs(struct task_struct *child, __u32 __user *data) 152 { 153 fpureg_t *fregs; 154 int i; 155 156 if (!access_ok(VERIFY_READ, data, 33 * 8)) 157 return -EIO; 158 159 fregs = get_fpu_regs(child); 160 161 for (i = 0; i < 32; i++) 162 __get_user(fregs[i], i + (__u64 __user *) data); 163 164 __get_user(child->thread.fpu.fcr31, data + 64); 165 166 /* FIR may not be written. */ 167 168 return 0; 169 } 170 171 int ptrace_get_watch_regs(struct task_struct *child, 172 struct pt_watch_regs __user *addr) 173 { 174 enum pt_watch_style style; 175 int i; 176 177 if (!cpu_has_watch || current_cpu_data.watch_reg_use_cnt == 0) 178 return -EIO; 179 if (!access_ok(VERIFY_WRITE, addr, sizeof(struct pt_watch_regs))) 180 return -EIO; 181 182 #ifdef CONFIG_32BIT 183 style = pt_watch_style_mips32; 184 #define WATCH_STYLE mips32 185 #else 186 style = pt_watch_style_mips64; 187 #define WATCH_STYLE mips64 188 #endif 189 190 __put_user(style, &addr->style); 191 __put_user(current_cpu_data.watch_reg_use_cnt, 192 &addr->WATCH_STYLE.num_valid); 193 for (i = 0; i < current_cpu_data.watch_reg_use_cnt; i++) { 194 __put_user(child->thread.watch.mips3264.watchlo[i], 195 &addr->WATCH_STYLE.watchlo[i]); 196 __put_user(child->thread.watch.mips3264.watchhi[i] & 0xfff, 197 &addr->WATCH_STYLE.watchhi[i]); 198 __put_user(current_cpu_data.watch_reg_masks[i], 199 &addr->WATCH_STYLE.watch_masks[i]); 200 } 201 for (; i < 8; i++) { 202 __put_user(0, &addr->WATCH_STYLE.watchlo[i]); 203 __put_user(0, &addr->WATCH_STYLE.watchhi[i]); 204 __put_user(0, &addr->WATCH_STYLE.watch_masks[i]); 205 } 206 207 return 0; 208 } 209 210 int ptrace_set_watch_regs(struct task_struct *child, 211 struct pt_watch_regs __user *addr) 212 { 213 int i; 214 int watch_active = 0; 215 unsigned long lt[NUM_WATCH_REGS]; 216 u16 ht[NUM_WATCH_REGS]; 217 218 if (!cpu_has_watch || current_cpu_data.watch_reg_use_cnt == 0) 219 return -EIO; 220 if (!access_ok(VERIFY_READ, addr, sizeof(struct pt_watch_regs))) 221 return -EIO; 222 /* Check the values. */ 223 for (i = 0; i < current_cpu_data.watch_reg_use_cnt; i++) { 224 __get_user(lt[i], &addr->WATCH_STYLE.watchlo[i]); 225 #ifdef CONFIG_32BIT 226 if (lt[i] & __UA_LIMIT) 227 return -EINVAL; 228 #else 229 if (test_tsk_thread_flag(child, TIF_32BIT_ADDR)) { 230 if (lt[i] & 0xffffffff80000000UL) 231 return -EINVAL; 232 } else { 233 if (lt[i] & __UA_LIMIT) 234 return -EINVAL; 235 } 236 #endif 237 __get_user(ht[i], &addr->WATCH_STYLE.watchhi[i]); 238 if (ht[i] & ~0xff8) 239 return -EINVAL; 240 } 241 /* Install them. */ 242 for (i = 0; i < current_cpu_data.watch_reg_use_cnt; i++) { 243 if (lt[i] & 7) 244 watch_active = 1; 245 child->thread.watch.mips3264.watchlo[i] = lt[i]; 246 /* Set the G bit. */ 247 child->thread.watch.mips3264.watchhi[i] = ht[i]; 248 } 249 250 if (watch_active) 251 set_tsk_thread_flag(child, TIF_LOAD_WATCH); 252 else 253 clear_tsk_thread_flag(child, TIF_LOAD_WATCH); 254 255 return 0; 256 } 257 258 long arch_ptrace(struct task_struct *child, long request, long addr, long data) 259 { 260 int ret; 261 262 switch (request) { 263 /* when I and D space are separate, these will need to be fixed. */ 264 case PTRACE_PEEKTEXT: /* read word at location addr. */ 265 case PTRACE_PEEKDATA: 266 ret = generic_ptrace_peekdata(child, addr, data); 267 break; 268 269 /* Read the word at location addr in the USER area. */ 270 case PTRACE_PEEKUSR: { 271 struct pt_regs *regs; 272 unsigned long tmp = 0; 273 274 regs = task_pt_regs(child); 275 ret = 0; /* Default return value. */ 276 277 switch (addr) { 278 case 0 ... 31: 279 tmp = regs->regs[addr]; 280 break; 281 case FPR_BASE ... FPR_BASE + 31: 282 if (tsk_used_math(child)) { 283 fpureg_t *fregs = get_fpu_regs(child); 284 285 #ifdef CONFIG_32BIT 286 /* 287 * The odd registers are actually the high 288 * order bits of the values stored in the even 289 * registers - unless we're using r2k_switch.S. 290 */ 291 if (addr & 1) 292 tmp = (unsigned long) (fregs[((addr & ~1) - 32)] >> 32); 293 else 294 tmp = (unsigned long) (fregs[(addr - 32)] & 0xffffffff); 295 #endif 296 #ifdef CONFIG_64BIT 297 tmp = fregs[addr - FPR_BASE]; 298 #endif 299 } else { 300 tmp = -1; /* FP not yet used */ 301 } 302 break; 303 case PC: 304 tmp = regs->cp0_epc; 305 break; 306 case CAUSE: 307 tmp = regs->cp0_cause; 308 break; 309 case BADVADDR: 310 tmp = regs->cp0_badvaddr; 311 break; 312 case MMHI: 313 tmp = regs->hi; 314 break; 315 case MMLO: 316 tmp = regs->lo; 317 break; 318 #ifdef CONFIG_CPU_HAS_SMARTMIPS 319 case ACX: 320 tmp = regs->acx; 321 break; 322 #endif 323 case FPC_CSR: 324 tmp = child->thread.fpu.fcr31; 325 break; 326 case FPC_EIR: { /* implementation / version register */ 327 unsigned int flags; 328 #ifdef CONFIG_MIPS_MT_SMTC 329 unsigned long irqflags; 330 unsigned int mtflags; 331 #endif /* CONFIG_MIPS_MT_SMTC */ 332 333 preempt_disable(); 334 if (!cpu_has_fpu) { 335 preempt_enable(); 336 break; 337 } 338 339 #ifdef CONFIG_MIPS_MT_SMTC 340 /* Read-modify-write of Status must be atomic */ 341 local_irq_save(irqflags); 342 mtflags = dmt(); 343 #endif /* CONFIG_MIPS_MT_SMTC */ 344 if (cpu_has_mipsmt) { 345 unsigned int vpflags = dvpe(); 346 flags = read_c0_status(); 347 __enable_fpu(); 348 __asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp)); 349 write_c0_status(flags); 350 evpe(vpflags); 351 } else { 352 flags = read_c0_status(); 353 __enable_fpu(); 354 __asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp)); 355 write_c0_status(flags); 356 } 357 #ifdef CONFIG_MIPS_MT_SMTC 358 emt(mtflags); 359 local_irq_restore(irqflags); 360 #endif /* CONFIG_MIPS_MT_SMTC */ 361 preempt_enable(); 362 break; 363 } 364 case DSP_BASE ... DSP_BASE + 5: { 365 dspreg_t *dregs; 366 367 if (!cpu_has_dsp) { 368 tmp = 0; 369 ret = -EIO; 370 goto out; 371 } 372 dregs = __get_dsp_regs(child); 373 tmp = (unsigned long) (dregs[addr - DSP_BASE]); 374 break; 375 } 376 case DSP_CONTROL: 377 if (!cpu_has_dsp) { 378 tmp = 0; 379 ret = -EIO; 380 goto out; 381 } 382 tmp = child->thread.dsp.dspcontrol; 383 break; 384 default: 385 tmp = 0; 386 ret = -EIO; 387 goto out; 388 } 389 ret = put_user(tmp, (unsigned long __user *) data); 390 break; 391 } 392 393 /* when I and D space are separate, this will have to be fixed. */ 394 case PTRACE_POKETEXT: /* write the word at location addr. */ 395 case PTRACE_POKEDATA: 396 ret = generic_ptrace_pokedata(child, addr, data); 397 break; 398 399 case PTRACE_POKEUSR: { 400 struct pt_regs *regs; 401 ret = 0; 402 regs = task_pt_regs(child); 403 404 switch (addr) { 405 case 0 ... 31: 406 regs->regs[addr] = data; 407 break; 408 case FPR_BASE ... FPR_BASE + 31: { 409 fpureg_t *fregs = get_fpu_regs(child); 410 411 if (!tsk_used_math(child)) { 412 /* FP not yet used */ 413 memset(&child->thread.fpu, ~0, 414 sizeof(child->thread.fpu)); 415 child->thread.fpu.fcr31 = 0; 416 } 417 #ifdef CONFIG_32BIT 418 /* 419 * The odd registers are actually the high order bits 420 * of the values stored in the even registers - unless 421 * we're using r2k_switch.S. 422 */ 423 if (addr & 1) { 424 fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff; 425 fregs[(addr & ~1) - FPR_BASE] |= ((unsigned long long) data) << 32; 426 } else { 427 fregs[addr - FPR_BASE] &= ~0xffffffffLL; 428 fregs[addr - FPR_BASE] |= data; 429 } 430 #endif 431 #ifdef CONFIG_64BIT 432 fregs[addr - FPR_BASE] = data; 433 #endif 434 break; 435 } 436 case PC: 437 regs->cp0_epc = data; 438 break; 439 case MMHI: 440 regs->hi = data; 441 break; 442 case MMLO: 443 regs->lo = data; 444 break; 445 #ifdef CONFIG_CPU_HAS_SMARTMIPS 446 case ACX: 447 regs->acx = data; 448 break; 449 #endif 450 case FPC_CSR: 451 child->thread.fpu.fcr31 = data; 452 break; 453 case DSP_BASE ... DSP_BASE + 5: { 454 dspreg_t *dregs; 455 456 if (!cpu_has_dsp) { 457 ret = -EIO; 458 break; 459 } 460 461 dregs = __get_dsp_regs(child); 462 dregs[addr - DSP_BASE] = data; 463 break; 464 } 465 case DSP_CONTROL: 466 if (!cpu_has_dsp) { 467 ret = -EIO; 468 break; 469 } 470 child->thread.dsp.dspcontrol = data; 471 break; 472 default: 473 /* The rest are not allowed. */ 474 ret = -EIO; 475 break; 476 } 477 break; 478 } 479 480 case PTRACE_GETREGS: 481 ret = ptrace_getregs(child, (__s64 __user *) data); 482 break; 483 484 case PTRACE_SETREGS: 485 ret = ptrace_setregs(child, (__s64 __user *) data); 486 break; 487 488 case PTRACE_GETFPREGS: 489 ret = ptrace_getfpregs(child, (__u32 __user *) data); 490 break; 491 492 case PTRACE_SETFPREGS: 493 ret = ptrace_setfpregs(child, (__u32 __user *) data); 494 break; 495 496 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ 497 case PTRACE_CONT: { /* restart after signal. */ 498 ret = -EIO; 499 if (!valid_signal(data)) 500 break; 501 if (request == PTRACE_SYSCALL) { 502 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 503 } 504 else { 505 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 506 } 507 child->exit_code = data; 508 wake_up_process(child); 509 ret = 0; 510 break; 511 } 512 513 /* 514 * make the child exit. Best I can do is send it a sigkill. 515 * perhaps it should be put in the status that it wants to 516 * exit. 517 */ 518 case PTRACE_KILL: 519 ret = 0; 520 if (child->exit_state == EXIT_ZOMBIE) /* already dead */ 521 break; 522 child->exit_code = SIGKILL; 523 wake_up_process(child); 524 break; 525 526 case PTRACE_GET_THREAD_AREA: 527 ret = put_user(task_thread_info(child)->tp_value, 528 (unsigned long __user *) data); 529 break; 530 531 case PTRACE_GET_WATCH_REGS: 532 ret = ptrace_get_watch_regs(child, 533 (struct pt_watch_regs __user *) addr); 534 break; 535 536 case PTRACE_SET_WATCH_REGS: 537 ret = ptrace_set_watch_regs(child, 538 (struct pt_watch_regs __user *) addr); 539 break; 540 541 default: 542 ret = ptrace_request(child, request, addr, data); 543 break; 544 } 545 out: 546 return ret; 547 } 548 549 static inline int audit_arch(void) 550 { 551 int arch = EM_MIPS; 552 #ifdef CONFIG_64BIT 553 arch |= __AUDIT_ARCH_64BIT; 554 #endif 555 #if defined(__LITTLE_ENDIAN) 556 arch |= __AUDIT_ARCH_LE; 557 #endif 558 return arch; 559 } 560 561 /* 562 * Notification of system call entry/exit 563 * - triggered by current->work.syscall_trace 564 */ 565 asmlinkage void do_syscall_trace(struct pt_regs *regs, int entryexit) 566 { 567 /* do the secure computing check first */ 568 if (!entryexit) 569 secure_computing(regs->regs[0]); 570 571 if (unlikely(current->audit_context) && entryexit) 572 audit_syscall_exit(AUDITSC_RESULT(regs->regs[2]), 573 regs->regs[2]); 574 575 if (!(current->ptrace & PT_PTRACED)) 576 goto out; 577 578 if (!test_thread_flag(TIF_SYSCALL_TRACE)) 579 goto out; 580 581 /* The 0x80 provides a way for the tracing parent to distinguish 582 between a syscall stop and SIGTRAP delivery */ 583 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) ? 584 0x80 : 0)); 585 586 /* 587 * this isn't the same as continuing with a signal, but it will do 588 * for normal use. strace only continues with a signal if the 589 * stopping signal is not SIGTRAP. -brl 590 */ 591 if (current->exit_code) { 592 send_sig(current->exit_code, current, 1); 593 current->exit_code = 0; 594 } 595 596 out: 597 if (unlikely(current->audit_context) && !entryexit) 598 audit_syscall_entry(audit_arch(), regs->regs[0], 599 regs->regs[4], regs->regs[5], 600 regs->regs[6], regs->regs[7]); 601 } 602