1 /* 2 * Ptrace user space interface. 3 * 4 * Copyright IBM Corp. 1999, 2010 5 * Author(s): Denis Joseph Barrow 6 * Martin Schwidefsky (schwidefsky@de.ibm.com) 7 */ 8 9 #include <linux/kernel.h> 10 #include <linux/sched.h> 11 #include <linux/mm.h> 12 #include <linux/smp.h> 13 #include <linux/errno.h> 14 #include <linux/ptrace.h> 15 #include <linux/user.h> 16 #include <linux/security.h> 17 #include <linux/audit.h> 18 #include <linux/signal.h> 19 #include <linux/elf.h> 20 #include <linux/regset.h> 21 #include <linux/tracehook.h> 22 #include <linux/seccomp.h> 23 #include <linux/compat.h> 24 #include <trace/syscall.h> 25 #include <asm/segment.h> 26 #include <asm/page.h> 27 #include <asm/pgtable.h> 28 #include <asm/pgalloc.h> 29 #include <asm/uaccess.h> 30 #include <asm/unistd.h> 31 #include <asm/switch_to.h> 32 #include "entry.h" 33 34 #ifdef CONFIG_COMPAT 35 #include "compat_ptrace.h" 36 #endif 37 38 #define CREATE_TRACE_POINTS 39 #include <trace/events/syscalls.h> 40 41 enum s390_regset { 42 REGSET_GENERAL, 43 REGSET_FP, 44 REGSET_LAST_BREAK, 45 REGSET_TDB, 46 REGSET_SYSTEM_CALL, 47 REGSET_GENERAL_EXTENDED, 48 }; 49 50 void update_cr_regs(struct task_struct *task) 51 { 52 struct pt_regs *regs = task_pt_regs(task); 53 struct thread_struct *thread = &task->thread; 54 struct per_regs old, new; 55 56 #ifdef CONFIG_64BIT 57 /* Take care of the enable/disable of transactional execution. */ 58 if (MACHINE_HAS_TE) { 59 unsigned long cr, cr_new; 60 61 __ctl_store(cr, 0, 0); 62 /* Set or clear transaction execution TXC bit 8. */ 63 cr_new = cr | (1UL << 55); 64 if (task->thread.per_flags & PER_FLAG_NO_TE) 65 cr_new &= ~(1UL << 55); 66 if (cr_new != cr) 67 __ctl_load(cr_new, 0, 0); 68 /* Set or clear transaction execution TDC bits 62 and 63. */ 69 __ctl_store(cr, 2, 2); 70 cr_new = cr & ~3UL; 71 if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) { 72 if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND_TEND) 73 cr_new |= 1UL; 74 else 75 cr_new |= 2UL; 76 } 77 if (cr_new != cr) 78 __ctl_load(cr_new, 2, 2); 79 } 80 #endif 81 /* Copy user specified PER registers */ 82 new.control = thread->per_user.control; 83 new.start = thread->per_user.start; 84 new.end = thread->per_user.end; 85 86 /* merge TIF_SINGLE_STEP into user specified PER registers. */ 87 if (test_tsk_thread_flag(task, TIF_SINGLE_STEP)) { 88 if (test_tsk_thread_flag(task, TIF_BLOCK_STEP)) 89 new.control |= PER_EVENT_BRANCH; 90 else 91 new.control |= PER_EVENT_IFETCH; 92 #ifdef CONFIG_64BIT 93 new.control |= PER_CONTROL_SUSPENSION; 94 new.control |= PER_EVENT_TRANSACTION_END; 95 #endif 96 new.start = 0; 97 new.end = PSW_ADDR_INSN; 98 } 99 100 /* Take care of the PER enablement bit in the PSW. */ 101 if (!(new.control & PER_EVENT_MASK)) { 102 regs->psw.mask &= ~PSW_MASK_PER; 103 return; 104 } 105 regs->psw.mask |= PSW_MASK_PER; 106 __ctl_store(old, 9, 11); 107 if (memcmp(&new, &old, sizeof(struct per_regs)) != 0) 108 __ctl_load(new, 9, 11); 109 } 110 111 void user_enable_single_step(struct task_struct *task) 112 { 113 clear_tsk_thread_flag(task, TIF_BLOCK_STEP); 114 set_tsk_thread_flag(task, TIF_SINGLE_STEP); 115 } 116 117 void user_disable_single_step(struct task_struct *task) 118 { 119 clear_tsk_thread_flag(task, TIF_BLOCK_STEP); 120 clear_tsk_thread_flag(task, TIF_SINGLE_STEP); 121 } 122 123 void user_enable_block_step(struct task_struct *task) 124 { 125 set_tsk_thread_flag(task, TIF_SINGLE_STEP); 126 set_tsk_thread_flag(task, TIF_BLOCK_STEP); 127 } 128 129 /* 130 * Called by kernel/ptrace.c when detaching.. 131 * 132 * Clear all debugging related fields. 133 */ 134 void ptrace_disable(struct task_struct *task) 135 { 136 memset(&task->thread.per_user, 0, sizeof(task->thread.per_user)); 137 memset(&task->thread.per_event, 0, sizeof(task->thread.per_event)); 138 clear_tsk_thread_flag(task, TIF_SINGLE_STEP); 139 clear_tsk_thread_flag(task, TIF_PER_TRAP); 140 task->thread.per_flags = 0; 141 } 142 143 #ifndef CONFIG_64BIT 144 # define __ADDR_MASK 3 145 #else 146 # define __ADDR_MASK 7 147 #endif 148 149 static inline unsigned long __peek_user_per(struct task_struct *child, 150 addr_t addr) 151 { 152 struct per_struct_kernel *dummy = NULL; 153 154 if (addr == (addr_t) &dummy->cr9) 155 /* Control bits of the active per set. */ 156 return test_thread_flag(TIF_SINGLE_STEP) ? 157 PER_EVENT_IFETCH : child->thread.per_user.control; 158 else if (addr == (addr_t) &dummy->cr10) 159 /* Start address of the active per set. */ 160 return test_thread_flag(TIF_SINGLE_STEP) ? 161 0 : child->thread.per_user.start; 162 else if (addr == (addr_t) &dummy->cr11) 163 /* End address of the active per set. */ 164 return test_thread_flag(TIF_SINGLE_STEP) ? 165 PSW_ADDR_INSN : child->thread.per_user.end; 166 else if (addr == (addr_t) &dummy->bits) 167 /* Single-step bit. */ 168 return test_thread_flag(TIF_SINGLE_STEP) ? 169 (1UL << (BITS_PER_LONG - 1)) : 0; 170 else if (addr == (addr_t) &dummy->starting_addr) 171 /* Start address of the user specified per set. */ 172 return child->thread.per_user.start; 173 else if (addr == (addr_t) &dummy->ending_addr) 174 /* End address of the user specified per set. */ 175 return child->thread.per_user.end; 176 else if (addr == (addr_t) &dummy->perc_atmid) 177 /* PER code, ATMID and AI of the last PER trap */ 178 return (unsigned long) 179 child->thread.per_event.cause << (BITS_PER_LONG - 16); 180 else if (addr == (addr_t) &dummy->address) 181 /* Address of the last PER trap */ 182 return child->thread.per_event.address; 183 else if (addr == (addr_t) &dummy->access_id) 184 /* Access id of the last PER trap */ 185 return (unsigned long) 186 child->thread.per_event.paid << (BITS_PER_LONG - 8); 187 return 0; 188 } 189 190 /* 191 * Read the word at offset addr from the user area of a process. The 192 * trouble here is that the information is littered over different 193 * locations. The process registers are found on the kernel stack, 194 * the floating point stuff and the trace settings are stored in 195 * the task structure. In addition the different structures in 196 * struct user contain pad bytes that should be read as zeroes. 197 * Lovely... 198 */ 199 static unsigned long __peek_user(struct task_struct *child, addr_t addr) 200 { 201 struct user *dummy = NULL; 202 addr_t offset, tmp; 203 204 if (addr < (addr_t) &dummy->regs.acrs) { 205 /* 206 * psw and gprs are stored on the stack 207 */ 208 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr); 209 if (addr == (addr_t) &dummy->regs.psw.mask) { 210 /* Return a clean psw mask. */ 211 tmp &= PSW_MASK_USER | PSW_MASK_RI; 212 tmp |= PSW_USER_BITS; 213 } 214 215 } else if (addr < (addr_t) &dummy->regs.orig_gpr2) { 216 /* 217 * access registers are stored in the thread structure 218 */ 219 offset = addr - (addr_t) &dummy->regs.acrs; 220 #ifdef CONFIG_64BIT 221 /* 222 * Very special case: old & broken 64 bit gdb reading 223 * from acrs[15]. Result is a 64 bit value. Read the 224 * 32 bit acrs[15] value and shift it by 32. Sick... 225 */ 226 if (addr == (addr_t) &dummy->regs.acrs[15]) 227 tmp = ((unsigned long) child->thread.acrs[15]) << 32; 228 else 229 #endif 230 tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset); 231 232 } else if (addr == (addr_t) &dummy->regs.orig_gpr2) { 233 /* 234 * orig_gpr2 is stored on the kernel stack 235 */ 236 tmp = (addr_t) task_pt_regs(child)->orig_gpr2; 237 238 } else if (addr < (addr_t) &dummy->regs.fp_regs) { 239 /* 240 * prevent reads of padding hole between 241 * orig_gpr2 and fp_regs on s390. 242 */ 243 tmp = 0; 244 245 } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) { 246 /* 247 * floating point regs. are stored in the thread structure 248 */ 249 offset = addr - (addr_t) &dummy->regs.fp_regs; 250 tmp = *(addr_t *)((addr_t) &child->thread.fp_regs + offset); 251 if (addr == (addr_t) &dummy->regs.fp_regs.fpc) 252 tmp <<= BITS_PER_LONG - 32; 253 254 } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) { 255 /* 256 * Handle access to the per_info structure. 257 */ 258 addr -= (addr_t) &dummy->regs.per_info; 259 tmp = __peek_user_per(child, addr); 260 261 } else 262 tmp = 0; 263 264 return tmp; 265 } 266 267 static int 268 peek_user(struct task_struct *child, addr_t addr, addr_t data) 269 { 270 addr_t tmp, mask; 271 272 /* 273 * Stupid gdb peeks/pokes the access registers in 64 bit with 274 * an alignment of 4. Programmers from hell... 275 */ 276 mask = __ADDR_MASK; 277 #ifdef CONFIG_64BIT 278 if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs && 279 addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2) 280 mask = 3; 281 #endif 282 if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK) 283 return -EIO; 284 285 tmp = __peek_user(child, addr); 286 return put_user(tmp, (addr_t __user *) data); 287 } 288 289 static inline void __poke_user_per(struct task_struct *child, 290 addr_t addr, addr_t data) 291 { 292 struct per_struct_kernel *dummy = NULL; 293 294 /* 295 * There are only three fields in the per_info struct that the 296 * debugger user can write to. 297 * 1) cr9: the debugger wants to set a new PER event mask 298 * 2) starting_addr: the debugger wants to set a new starting 299 * address to use with the PER event mask. 300 * 3) ending_addr: the debugger wants to set a new ending 301 * address to use with the PER event mask. 302 * The user specified PER event mask and the start and end 303 * addresses are used only if single stepping is not in effect. 304 * Writes to any other field in per_info are ignored. 305 */ 306 if (addr == (addr_t) &dummy->cr9) 307 /* PER event mask of the user specified per set. */ 308 child->thread.per_user.control = 309 data & (PER_EVENT_MASK | PER_CONTROL_MASK); 310 else if (addr == (addr_t) &dummy->starting_addr) 311 /* Starting address of the user specified per set. */ 312 child->thread.per_user.start = data; 313 else if (addr == (addr_t) &dummy->ending_addr) 314 /* Ending address of the user specified per set. */ 315 child->thread.per_user.end = data; 316 } 317 318 /* 319 * Write a word to the user area of a process at location addr. This 320 * operation does have an additional problem compared to peek_user. 321 * Stores to the program status word and on the floating point 322 * control register needs to get checked for validity. 323 */ 324 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data) 325 { 326 struct user *dummy = NULL; 327 addr_t offset; 328 329 if (addr < (addr_t) &dummy->regs.acrs) { 330 /* 331 * psw and gprs are stored on the stack 332 */ 333 if (addr == (addr_t) &dummy->regs.psw.mask) { 334 unsigned long mask = PSW_MASK_USER; 335 336 mask |= is_ri_task(child) ? PSW_MASK_RI : 0; 337 if ((data & ~mask) != PSW_USER_BITS) 338 return -EINVAL; 339 if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA)) 340 return -EINVAL; 341 } 342 *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data; 343 344 } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) { 345 /* 346 * access registers are stored in the thread structure 347 */ 348 offset = addr - (addr_t) &dummy->regs.acrs; 349 #ifdef CONFIG_64BIT 350 /* 351 * Very special case: old & broken 64 bit gdb writing 352 * to acrs[15] with a 64 bit value. Ignore the lower 353 * half of the value and write the upper 32 bit to 354 * acrs[15]. Sick... 355 */ 356 if (addr == (addr_t) &dummy->regs.acrs[15]) 357 child->thread.acrs[15] = (unsigned int) (data >> 32); 358 else 359 #endif 360 *(addr_t *)((addr_t) &child->thread.acrs + offset) = data; 361 362 } else if (addr == (addr_t) &dummy->regs.orig_gpr2) { 363 /* 364 * orig_gpr2 is stored on the kernel stack 365 */ 366 task_pt_regs(child)->orig_gpr2 = data; 367 368 } else if (addr < (addr_t) &dummy->regs.fp_regs) { 369 /* 370 * prevent writes of padding hole between 371 * orig_gpr2 and fp_regs on s390. 372 */ 373 return 0; 374 375 } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) { 376 /* 377 * floating point regs. are stored in the thread structure 378 */ 379 if (addr == (addr_t) &dummy->regs.fp_regs.fpc) 380 if ((unsigned int) data != 0 || 381 test_fp_ctl(data >> (BITS_PER_LONG - 32))) 382 return -EINVAL; 383 offset = addr - (addr_t) &dummy->regs.fp_regs; 384 *(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data; 385 386 } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) { 387 /* 388 * Handle access to the per_info structure. 389 */ 390 addr -= (addr_t) &dummy->regs.per_info; 391 __poke_user_per(child, addr, data); 392 393 } 394 395 return 0; 396 } 397 398 static int poke_user(struct task_struct *child, addr_t addr, addr_t data) 399 { 400 addr_t mask; 401 402 /* 403 * Stupid gdb peeks/pokes the access registers in 64 bit with 404 * an alignment of 4. Programmers from hell indeed... 405 */ 406 mask = __ADDR_MASK; 407 #ifdef CONFIG_64BIT 408 if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs && 409 addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2) 410 mask = 3; 411 #endif 412 if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK) 413 return -EIO; 414 415 return __poke_user(child, addr, data); 416 } 417 418 long arch_ptrace(struct task_struct *child, long request, 419 unsigned long addr, unsigned long data) 420 { 421 ptrace_area parea; 422 int copied, ret; 423 424 switch (request) { 425 case PTRACE_PEEKUSR: 426 /* read the word at location addr in the USER area. */ 427 return peek_user(child, addr, data); 428 429 case PTRACE_POKEUSR: 430 /* write the word at location addr in the USER area */ 431 return poke_user(child, addr, data); 432 433 case PTRACE_PEEKUSR_AREA: 434 case PTRACE_POKEUSR_AREA: 435 if (copy_from_user(&parea, (void __force __user *) addr, 436 sizeof(parea))) 437 return -EFAULT; 438 addr = parea.kernel_addr; 439 data = parea.process_addr; 440 copied = 0; 441 while (copied < parea.len) { 442 if (request == PTRACE_PEEKUSR_AREA) 443 ret = peek_user(child, addr, data); 444 else { 445 addr_t utmp; 446 if (get_user(utmp, 447 (addr_t __force __user *) data)) 448 return -EFAULT; 449 ret = poke_user(child, addr, utmp); 450 } 451 if (ret) 452 return ret; 453 addr += sizeof(unsigned long); 454 data += sizeof(unsigned long); 455 copied += sizeof(unsigned long); 456 } 457 return 0; 458 case PTRACE_GET_LAST_BREAK: 459 put_user(task_thread_info(child)->last_break, 460 (unsigned long __user *) data); 461 return 0; 462 case PTRACE_ENABLE_TE: 463 if (!MACHINE_HAS_TE) 464 return -EIO; 465 child->thread.per_flags &= ~PER_FLAG_NO_TE; 466 return 0; 467 case PTRACE_DISABLE_TE: 468 if (!MACHINE_HAS_TE) 469 return -EIO; 470 child->thread.per_flags |= PER_FLAG_NO_TE; 471 child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND; 472 return 0; 473 case PTRACE_TE_ABORT_RAND: 474 if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE)) 475 return -EIO; 476 switch (data) { 477 case 0UL: 478 child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND; 479 break; 480 case 1UL: 481 child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND; 482 child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND; 483 break; 484 case 2UL: 485 child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND; 486 child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND; 487 break; 488 default: 489 return -EINVAL; 490 } 491 return 0; 492 default: 493 /* Removing high order bit from addr (only for 31 bit). */ 494 addr &= PSW_ADDR_INSN; 495 return ptrace_request(child, request, addr, data); 496 } 497 } 498 499 #ifdef CONFIG_COMPAT 500 /* 501 * Now the fun part starts... a 31 bit program running in the 502 * 31 bit emulation tracing another program. PTRACE_PEEKTEXT, 503 * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy 504 * to handle, the difference to the 64 bit versions of the requests 505 * is that the access is done in multiples of 4 byte instead of 506 * 8 bytes (sizeof(unsigned long) on 31/64 bit). 507 * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA, 508 * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program 509 * is a 31 bit program too, the content of struct user can be 510 * emulated. A 31 bit program peeking into the struct user of 511 * a 64 bit program is a no-no. 512 */ 513 514 /* 515 * Same as peek_user_per but for a 31 bit program. 516 */ 517 static inline __u32 __peek_user_per_compat(struct task_struct *child, 518 addr_t addr) 519 { 520 struct compat_per_struct_kernel *dummy32 = NULL; 521 522 if (addr == (addr_t) &dummy32->cr9) 523 /* Control bits of the active per set. */ 524 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ? 525 PER_EVENT_IFETCH : child->thread.per_user.control; 526 else if (addr == (addr_t) &dummy32->cr10) 527 /* Start address of the active per set. */ 528 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ? 529 0 : child->thread.per_user.start; 530 else if (addr == (addr_t) &dummy32->cr11) 531 /* End address of the active per set. */ 532 return test_thread_flag(TIF_SINGLE_STEP) ? 533 PSW32_ADDR_INSN : child->thread.per_user.end; 534 else if (addr == (addr_t) &dummy32->bits) 535 /* Single-step bit. */ 536 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ? 537 0x80000000 : 0; 538 else if (addr == (addr_t) &dummy32->starting_addr) 539 /* Start address of the user specified per set. */ 540 return (__u32) child->thread.per_user.start; 541 else if (addr == (addr_t) &dummy32->ending_addr) 542 /* End address of the user specified per set. */ 543 return (__u32) child->thread.per_user.end; 544 else if (addr == (addr_t) &dummy32->perc_atmid) 545 /* PER code, ATMID and AI of the last PER trap */ 546 return (__u32) child->thread.per_event.cause << 16; 547 else if (addr == (addr_t) &dummy32->address) 548 /* Address of the last PER trap */ 549 return (__u32) child->thread.per_event.address; 550 else if (addr == (addr_t) &dummy32->access_id) 551 /* Access id of the last PER trap */ 552 return (__u32) child->thread.per_event.paid << 24; 553 return 0; 554 } 555 556 /* 557 * Same as peek_user but for a 31 bit program. 558 */ 559 static u32 __peek_user_compat(struct task_struct *child, addr_t addr) 560 { 561 struct compat_user *dummy32 = NULL; 562 addr_t offset; 563 __u32 tmp; 564 565 if (addr < (addr_t) &dummy32->regs.acrs) { 566 struct pt_regs *regs = task_pt_regs(child); 567 /* 568 * psw and gprs are stored on the stack 569 */ 570 if (addr == (addr_t) &dummy32->regs.psw.mask) { 571 /* Fake a 31 bit psw mask. */ 572 tmp = (__u32)(regs->psw.mask >> 32); 573 tmp &= PSW32_MASK_USER | PSW32_MASK_RI; 574 tmp |= PSW32_USER_BITS; 575 } else if (addr == (addr_t) &dummy32->regs.psw.addr) { 576 /* Fake a 31 bit psw address. */ 577 tmp = (__u32) regs->psw.addr | 578 (__u32)(regs->psw.mask & PSW_MASK_BA); 579 } else { 580 /* gpr 0-15 */ 581 tmp = *(__u32 *)((addr_t) ®s->psw + addr*2 + 4); 582 } 583 } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) { 584 /* 585 * access registers are stored in the thread structure 586 */ 587 offset = addr - (addr_t) &dummy32->regs.acrs; 588 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset); 589 590 } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) { 591 /* 592 * orig_gpr2 is stored on the kernel stack 593 */ 594 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4); 595 596 } else if (addr < (addr_t) &dummy32->regs.fp_regs) { 597 /* 598 * prevent reads of padding hole between 599 * orig_gpr2 and fp_regs on s390. 600 */ 601 tmp = 0; 602 603 } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) { 604 /* 605 * floating point regs. are stored in the thread structure 606 */ 607 offset = addr - (addr_t) &dummy32->regs.fp_regs; 608 tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset); 609 610 } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) { 611 /* 612 * Handle access to the per_info structure. 613 */ 614 addr -= (addr_t) &dummy32->regs.per_info; 615 tmp = __peek_user_per_compat(child, addr); 616 617 } else 618 tmp = 0; 619 620 return tmp; 621 } 622 623 static int peek_user_compat(struct task_struct *child, 624 addr_t addr, addr_t data) 625 { 626 __u32 tmp; 627 628 if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3) 629 return -EIO; 630 631 tmp = __peek_user_compat(child, addr); 632 return put_user(tmp, (__u32 __user *) data); 633 } 634 635 /* 636 * Same as poke_user_per but for a 31 bit program. 637 */ 638 static inline void __poke_user_per_compat(struct task_struct *child, 639 addr_t addr, __u32 data) 640 { 641 struct compat_per_struct_kernel *dummy32 = NULL; 642 643 if (addr == (addr_t) &dummy32->cr9) 644 /* PER event mask of the user specified per set. */ 645 child->thread.per_user.control = 646 data & (PER_EVENT_MASK | PER_CONTROL_MASK); 647 else if (addr == (addr_t) &dummy32->starting_addr) 648 /* Starting address of the user specified per set. */ 649 child->thread.per_user.start = data; 650 else if (addr == (addr_t) &dummy32->ending_addr) 651 /* Ending address of the user specified per set. */ 652 child->thread.per_user.end = data; 653 } 654 655 /* 656 * Same as poke_user but for a 31 bit program. 657 */ 658 static int __poke_user_compat(struct task_struct *child, 659 addr_t addr, addr_t data) 660 { 661 struct compat_user *dummy32 = NULL; 662 __u32 tmp = (__u32) data; 663 addr_t offset; 664 665 if (addr < (addr_t) &dummy32->regs.acrs) { 666 struct pt_regs *regs = task_pt_regs(child); 667 /* 668 * psw, gprs, acrs and orig_gpr2 are stored on the stack 669 */ 670 if (addr == (addr_t) &dummy32->regs.psw.mask) { 671 __u32 mask = PSW32_MASK_USER; 672 673 mask |= is_ri_task(child) ? PSW32_MASK_RI : 0; 674 /* Build a 64 bit psw mask from 31 bit mask. */ 675 if ((tmp & ~mask) != PSW32_USER_BITS) 676 /* Invalid psw mask. */ 677 return -EINVAL; 678 regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) | 679 (regs->psw.mask & PSW_MASK_BA) | 680 (__u64)(tmp & mask) << 32; 681 } else if (addr == (addr_t) &dummy32->regs.psw.addr) { 682 /* Build a 64 bit psw address from 31 bit address. */ 683 regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN; 684 /* Transfer 31 bit amode bit to psw mask. */ 685 regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) | 686 (__u64)(tmp & PSW32_ADDR_AMODE); 687 } else { 688 /* gpr 0-15 */ 689 *(__u32*)((addr_t) ®s->psw + addr*2 + 4) = tmp; 690 } 691 } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) { 692 /* 693 * access registers are stored in the thread structure 694 */ 695 offset = addr - (addr_t) &dummy32->regs.acrs; 696 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp; 697 698 } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) { 699 /* 700 * orig_gpr2 is stored on the kernel stack 701 */ 702 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp; 703 704 } else if (addr < (addr_t) &dummy32->regs.fp_regs) { 705 /* 706 * prevent writess of padding hole between 707 * orig_gpr2 and fp_regs on s390. 708 */ 709 return 0; 710 711 } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) { 712 /* 713 * floating point regs. are stored in the thread structure 714 */ 715 if (addr == (addr_t) &dummy32->regs.fp_regs.fpc && 716 test_fp_ctl(tmp)) 717 return -EINVAL; 718 offset = addr - (addr_t) &dummy32->regs.fp_regs; 719 *(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp; 720 721 } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) { 722 /* 723 * Handle access to the per_info structure. 724 */ 725 addr -= (addr_t) &dummy32->regs.per_info; 726 __poke_user_per_compat(child, addr, data); 727 } 728 729 return 0; 730 } 731 732 static int poke_user_compat(struct task_struct *child, 733 addr_t addr, addr_t data) 734 { 735 if (!is_compat_task() || (addr & 3) || 736 addr > sizeof(struct compat_user) - 3) 737 return -EIO; 738 739 return __poke_user_compat(child, addr, data); 740 } 741 742 long compat_arch_ptrace(struct task_struct *child, compat_long_t request, 743 compat_ulong_t caddr, compat_ulong_t cdata) 744 { 745 unsigned long addr = caddr; 746 unsigned long data = cdata; 747 compat_ptrace_area parea; 748 int copied, ret; 749 750 switch (request) { 751 case PTRACE_PEEKUSR: 752 /* read the word at location addr in the USER area. */ 753 return peek_user_compat(child, addr, data); 754 755 case PTRACE_POKEUSR: 756 /* write the word at location addr in the USER area */ 757 return poke_user_compat(child, addr, data); 758 759 case PTRACE_PEEKUSR_AREA: 760 case PTRACE_POKEUSR_AREA: 761 if (copy_from_user(&parea, (void __force __user *) addr, 762 sizeof(parea))) 763 return -EFAULT; 764 addr = parea.kernel_addr; 765 data = parea.process_addr; 766 copied = 0; 767 while (copied < parea.len) { 768 if (request == PTRACE_PEEKUSR_AREA) 769 ret = peek_user_compat(child, addr, data); 770 else { 771 __u32 utmp; 772 if (get_user(utmp, 773 (__u32 __force __user *) data)) 774 return -EFAULT; 775 ret = poke_user_compat(child, addr, utmp); 776 } 777 if (ret) 778 return ret; 779 addr += sizeof(unsigned int); 780 data += sizeof(unsigned int); 781 copied += sizeof(unsigned int); 782 } 783 return 0; 784 case PTRACE_GET_LAST_BREAK: 785 put_user(task_thread_info(child)->last_break, 786 (unsigned int __user *) data); 787 return 0; 788 } 789 return compat_ptrace_request(child, request, addr, data); 790 } 791 #endif 792 793 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs) 794 { 795 long ret = 0; 796 797 /* Do the secure computing check first. */ 798 if (secure_computing(regs->gprs[2])) { 799 /* seccomp failures shouldn't expose any additional code. */ 800 ret = -1; 801 goto out; 802 } 803 804 /* 805 * The sysc_tracesys code in entry.S stored the system 806 * call number to gprs[2]. 807 */ 808 if (test_thread_flag(TIF_SYSCALL_TRACE) && 809 (tracehook_report_syscall_entry(regs) || 810 regs->gprs[2] >= NR_syscalls)) { 811 /* 812 * Tracing decided this syscall should not happen or the 813 * debugger stored an invalid system call number. Skip 814 * the system call and the system call restart handling. 815 */ 816 clear_thread_flag(TIF_SYSCALL); 817 ret = -1; 818 } 819 820 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) 821 trace_sys_enter(regs, regs->gprs[2]); 822 823 audit_syscall_entry(is_compat_task() ? 824 AUDIT_ARCH_S390 : AUDIT_ARCH_S390X, 825 regs->gprs[2], regs->orig_gpr2, 826 regs->gprs[3], regs->gprs[4], 827 regs->gprs[5]); 828 out: 829 return ret ?: regs->gprs[2]; 830 } 831 832 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs) 833 { 834 audit_syscall_exit(regs); 835 836 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) 837 trace_sys_exit(regs, regs->gprs[2]); 838 839 if (test_thread_flag(TIF_SYSCALL_TRACE)) 840 tracehook_report_syscall_exit(regs, 0); 841 } 842 843 /* 844 * user_regset definitions. 845 */ 846 847 static int s390_regs_get(struct task_struct *target, 848 const struct user_regset *regset, 849 unsigned int pos, unsigned int count, 850 void *kbuf, void __user *ubuf) 851 { 852 if (target == current) 853 save_access_regs(target->thread.acrs); 854 855 if (kbuf) { 856 unsigned long *k = kbuf; 857 while (count > 0) { 858 *k++ = __peek_user(target, pos); 859 count -= sizeof(*k); 860 pos += sizeof(*k); 861 } 862 } else { 863 unsigned long __user *u = ubuf; 864 while (count > 0) { 865 if (__put_user(__peek_user(target, pos), u++)) 866 return -EFAULT; 867 count -= sizeof(*u); 868 pos += sizeof(*u); 869 } 870 } 871 return 0; 872 } 873 874 static int s390_regs_set(struct task_struct *target, 875 const struct user_regset *regset, 876 unsigned int pos, unsigned int count, 877 const void *kbuf, const void __user *ubuf) 878 { 879 int rc = 0; 880 881 if (target == current) 882 save_access_regs(target->thread.acrs); 883 884 if (kbuf) { 885 const unsigned long *k = kbuf; 886 while (count > 0 && !rc) { 887 rc = __poke_user(target, pos, *k++); 888 count -= sizeof(*k); 889 pos += sizeof(*k); 890 } 891 } else { 892 const unsigned long __user *u = ubuf; 893 while (count > 0 && !rc) { 894 unsigned long word; 895 rc = __get_user(word, u++); 896 if (rc) 897 break; 898 rc = __poke_user(target, pos, word); 899 count -= sizeof(*u); 900 pos += sizeof(*u); 901 } 902 } 903 904 if (rc == 0 && target == current) 905 restore_access_regs(target->thread.acrs); 906 907 return rc; 908 } 909 910 static int s390_fpregs_get(struct task_struct *target, 911 const struct user_regset *regset, unsigned int pos, 912 unsigned int count, void *kbuf, void __user *ubuf) 913 { 914 if (target == current) { 915 save_fp_ctl(&target->thread.fp_regs.fpc); 916 save_fp_regs(target->thread.fp_regs.fprs); 917 } 918 919 return user_regset_copyout(&pos, &count, &kbuf, &ubuf, 920 &target->thread.fp_regs, 0, -1); 921 } 922 923 static int s390_fpregs_set(struct task_struct *target, 924 const struct user_regset *regset, unsigned int pos, 925 unsigned int count, const void *kbuf, 926 const void __user *ubuf) 927 { 928 int rc = 0; 929 930 if (target == current) { 931 save_fp_ctl(&target->thread.fp_regs.fpc); 932 save_fp_regs(target->thread.fp_regs.fprs); 933 } 934 935 /* If setting FPC, must validate it first. */ 936 if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) { 937 u32 ufpc[2] = { target->thread.fp_regs.fpc, 0 }; 938 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc, 939 0, offsetof(s390_fp_regs, fprs)); 940 if (rc) 941 return rc; 942 if (ufpc[1] != 0 || test_fp_ctl(ufpc[0])) 943 return -EINVAL; 944 target->thread.fp_regs.fpc = ufpc[0]; 945 } 946 947 if (rc == 0 && count > 0) 948 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, 949 target->thread.fp_regs.fprs, 950 offsetof(s390_fp_regs, fprs), -1); 951 952 if (rc == 0 && target == current) { 953 restore_fp_ctl(&target->thread.fp_regs.fpc); 954 restore_fp_regs(target->thread.fp_regs.fprs); 955 } 956 957 return rc; 958 } 959 960 #ifdef CONFIG_64BIT 961 962 static int s390_last_break_get(struct task_struct *target, 963 const struct user_regset *regset, 964 unsigned int pos, unsigned int count, 965 void *kbuf, void __user *ubuf) 966 { 967 if (count > 0) { 968 if (kbuf) { 969 unsigned long *k = kbuf; 970 *k = task_thread_info(target)->last_break; 971 } else { 972 unsigned long __user *u = ubuf; 973 if (__put_user(task_thread_info(target)->last_break, u)) 974 return -EFAULT; 975 } 976 } 977 return 0; 978 } 979 980 static int s390_last_break_set(struct task_struct *target, 981 const struct user_regset *regset, 982 unsigned int pos, unsigned int count, 983 const void *kbuf, const void __user *ubuf) 984 { 985 return 0; 986 } 987 988 static int s390_tdb_get(struct task_struct *target, 989 const struct user_regset *regset, 990 unsigned int pos, unsigned int count, 991 void *kbuf, void __user *ubuf) 992 { 993 struct pt_regs *regs = task_pt_regs(target); 994 unsigned char *data; 995 996 if (!(regs->int_code & 0x200)) 997 return -ENODATA; 998 data = target->thread.trap_tdb; 999 return user_regset_copyout(&pos, &count, &kbuf, &ubuf, data, 0, 256); 1000 } 1001 1002 static int s390_tdb_set(struct task_struct *target, 1003 const struct user_regset *regset, 1004 unsigned int pos, unsigned int count, 1005 const void *kbuf, const void __user *ubuf) 1006 { 1007 return 0; 1008 } 1009 1010 #endif 1011 1012 static int s390_system_call_get(struct task_struct *target, 1013 const struct user_regset *regset, 1014 unsigned int pos, unsigned int count, 1015 void *kbuf, void __user *ubuf) 1016 { 1017 unsigned int *data = &task_thread_info(target)->system_call; 1018 return user_regset_copyout(&pos, &count, &kbuf, &ubuf, 1019 data, 0, sizeof(unsigned int)); 1020 } 1021 1022 static int s390_system_call_set(struct task_struct *target, 1023 const struct user_regset *regset, 1024 unsigned int pos, unsigned int count, 1025 const void *kbuf, const void __user *ubuf) 1026 { 1027 unsigned int *data = &task_thread_info(target)->system_call; 1028 return user_regset_copyin(&pos, &count, &kbuf, &ubuf, 1029 data, 0, sizeof(unsigned int)); 1030 } 1031 1032 static const struct user_regset s390_regsets[] = { 1033 [REGSET_GENERAL] = { 1034 .core_note_type = NT_PRSTATUS, 1035 .n = sizeof(s390_regs) / sizeof(long), 1036 .size = sizeof(long), 1037 .align = sizeof(long), 1038 .get = s390_regs_get, 1039 .set = s390_regs_set, 1040 }, 1041 [REGSET_FP] = { 1042 .core_note_type = NT_PRFPREG, 1043 .n = sizeof(s390_fp_regs) / sizeof(long), 1044 .size = sizeof(long), 1045 .align = sizeof(long), 1046 .get = s390_fpregs_get, 1047 .set = s390_fpregs_set, 1048 }, 1049 #ifdef CONFIG_64BIT 1050 [REGSET_LAST_BREAK] = { 1051 .core_note_type = NT_S390_LAST_BREAK, 1052 .n = 1, 1053 .size = sizeof(long), 1054 .align = sizeof(long), 1055 .get = s390_last_break_get, 1056 .set = s390_last_break_set, 1057 }, 1058 [REGSET_TDB] = { 1059 .core_note_type = NT_S390_TDB, 1060 .n = 1, 1061 .size = 256, 1062 .align = 1, 1063 .get = s390_tdb_get, 1064 .set = s390_tdb_set, 1065 }, 1066 #endif 1067 [REGSET_SYSTEM_CALL] = { 1068 .core_note_type = NT_S390_SYSTEM_CALL, 1069 .n = 1, 1070 .size = sizeof(unsigned int), 1071 .align = sizeof(unsigned int), 1072 .get = s390_system_call_get, 1073 .set = s390_system_call_set, 1074 }, 1075 }; 1076 1077 static const struct user_regset_view user_s390_view = { 1078 .name = UTS_MACHINE, 1079 .e_machine = EM_S390, 1080 .regsets = s390_regsets, 1081 .n = ARRAY_SIZE(s390_regsets) 1082 }; 1083 1084 #ifdef CONFIG_COMPAT 1085 static int s390_compat_regs_get(struct task_struct *target, 1086 const struct user_regset *regset, 1087 unsigned int pos, unsigned int count, 1088 void *kbuf, void __user *ubuf) 1089 { 1090 if (target == current) 1091 save_access_regs(target->thread.acrs); 1092 1093 if (kbuf) { 1094 compat_ulong_t *k = kbuf; 1095 while (count > 0) { 1096 *k++ = __peek_user_compat(target, pos); 1097 count -= sizeof(*k); 1098 pos += sizeof(*k); 1099 } 1100 } else { 1101 compat_ulong_t __user *u = ubuf; 1102 while (count > 0) { 1103 if (__put_user(__peek_user_compat(target, pos), u++)) 1104 return -EFAULT; 1105 count -= sizeof(*u); 1106 pos += sizeof(*u); 1107 } 1108 } 1109 return 0; 1110 } 1111 1112 static int s390_compat_regs_set(struct task_struct *target, 1113 const struct user_regset *regset, 1114 unsigned int pos, unsigned int count, 1115 const void *kbuf, const void __user *ubuf) 1116 { 1117 int rc = 0; 1118 1119 if (target == current) 1120 save_access_regs(target->thread.acrs); 1121 1122 if (kbuf) { 1123 const compat_ulong_t *k = kbuf; 1124 while (count > 0 && !rc) { 1125 rc = __poke_user_compat(target, pos, *k++); 1126 count -= sizeof(*k); 1127 pos += sizeof(*k); 1128 } 1129 } else { 1130 const compat_ulong_t __user *u = ubuf; 1131 while (count > 0 && !rc) { 1132 compat_ulong_t word; 1133 rc = __get_user(word, u++); 1134 if (rc) 1135 break; 1136 rc = __poke_user_compat(target, pos, word); 1137 count -= sizeof(*u); 1138 pos += sizeof(*u); 1139 } 1140 } 1141 1142 if (rc == 0 && target == current) 1143 restore_access_regs(target->thread.acrs); 1144 1145 return rc; 1146 } 1147 1148 static int s390_compat_regs_high_get(struct task_struct *target, 1149 const struct user_regset *regset, 1150 unsigned int pos, unsigned int count, 1151 void *kbuf, void __user *ubuf) 1152 { 1153 compat_ulong_t *gprs_high; 1154 1155 gprs_high = (compat_ulong_t *) 1156 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)]; 1157 if (kbuf) { 1158 compat_ulong_t *k = kbuf; 1159 while (count > 0) { 1160 *k++ = *gprs_high; 1161 gprs_high += 2; 1162 count -= sizeof(*k); 1163 } 1164 } else { 1165 compat_ulong_t __user *u = ubuf; 1166 while (count > 0) { 1167 if (__put_user(*gprs_high, u++)) 1168 return -EFAULT; 1169 gprs_high += 2; 1170 count -= sizeof(*u); 1171 } 1172 } 1173 return 0; 1174 } 1175 1176 static int s390_compat_regs_high_set(struct task_struct *target, 1177 const struct user_regset *regset, 1178 unsigned int pos, unsigned int count, 1179 const void *kbuf, const void __user *ubuf) 1180 { 1181 compat_ulong_t *gprs_high; 1182 int rc = 0; 1183 1184 gprs_high = (compat_ulong_t *) 1185 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)]; 1186 if (kbuf) { 1187 const compat_ulong_t *k = kbuf; 1188 while (count > 0) { 1189 *gprs_high = *k++; 1190 *gprs_high += 2; 1191 count -= sizeof(*k); 1192 } 1193 } else { 1194 const compat_ulong_t __user *u = ubuf; 1195 while (count > 0 && !rc) { 1196 unsigned long word; 1197 rc = __get_user(word, u++); 1198 if (rc) 1199 break; 1200 *gprs_high = word; 1201 *gprs_high += 2; 1202 count -= sizeof(*u); 1203 } 1204 } 1205 1206 return rc; 1207 } 1208 1209 static int s390_compat_last_break_get(struct task_struct *target, 1210 const struct user_regset *regset, 1211 unsigned int pos, unsigned int count, 1212 void *kbuf, void __user *ubuf) 1213 { 1214 compat_ulong_t last_break; 1215 1216 if (count > 0) { 1217 last_break = task_thread_info(target)->last_break; 1218 if (kbuf) { 1219 unsigned long *k = kbuf; 1220 *k = last_break; 1221 } else { 1222 unsigned long __user *u = ubuf; 1223 if (__put_user(last_break, u)) 1224 return -EFAULT; 1225 } 1226 } 1227 return 0; 1228 } 1229 1230 static int s390_compat_last_break_set(struct task_struct *target, 1231 const struct user_regset *regset, 1232 unsigned int pos, unsigned int count, 1233 const void *kbuf, const void __user *ubuf) 1234 { 1235 return 0; 1236 } 1237 1238 static const struct user_regset s390_compat_regsets[] = { 1239 [REGSET_GENERAL] = { 1240 .core_note_type = NT_PRSTATUS, 1241 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t), 1242 .size = sizeof(compat_long_t), 1243 .align = sizeof(compat_long_t), 1244 .get = s390_compat_regs_get, 1245 .set = s390_compat_regs_set, 1246 }, 1247 [REGSET_FP] = { 1248 .core_note_type = NT_PRFPREG, 1249 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t), 1250 .size = sizeof(compat_long_t), 1251 .align = sizeof(compat_long_t), 1252 .get = s390_fpregs_get, 1253 .set = s390_fpregs_set, 1254 }, 1255 [REGSET_LAST_BREAK] = { 1256 .core_note_type = NT_S390_LAST_BREAK, 1257 .n = 1, 1258 .size = sizeof(long), 1259 .align = sizeof(long), 1260 .get = s390_compat_last_break_get, 1261 .set = s390_compat_last_break_set, 1262 }, 1263 [REGSET_TDB] = { 1264 .core_note_type = NT_S390_TDB, 1265 .n = 1, 1266 .size = 256, 1267 .align = 1, 1268 .get = s390_tdb_get, 1269 .set = s390_tdb_set, 1270 }, 1271 [REGSET_SYSTEM_CALL] = { 1272 .core_note_type = NT_S390_SYSTEM_CALL, 1273 .n = 1, 1274 .size = sizeof(compat_uint_t), 1275 .align = sizeof(compat_uint_t), 1276 .get = s390_system_call_get, 1277 .set = s390_system_call_set, 1278 }, 1279 [REGSET_GENERAL_EXTENDED] = { 1280 .core_note_type = NT_S390_HIGH_GPRS, 1281 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t), 1282 .size = sizeof(compat_long_t), 1283 .align = sizeof(compat_long_t), 1284 .get = s390_compat_regs_high_get, 1285 .set = s390_compat_regs_high_set, 1286 }, 1287 }; 1288 1289 static const struct user_regset_view user_s390_compat_view = { 1290 .name = "s390", 1291 .e_machine = EM_S390, 1292 .regsets = s390_compat_regsets, 1293 .n = ARRAY_SIZE(s390_compat_regsets) 1294 }; 1295 #endif 1296 1297 const struct user_regset_view *task_user_regset_view(struct task_struct *task) 1298 { 1299 #ifdef CONFIG_COMPAT 1300 if (test_tsk_thread_flag(task, TIF_31BIT)) 1301 return &user_s390_compat_view; 1302 #endif 1303 return &user_s390_view; 1304 } 1305 1306 static const char *gpr_names[NUM_GPRS] = { 1307 "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", 1308 "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15", 1309 }; 1310 1311 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset) 1312 { 1313 if (offset >= NUM_GPRS) 1314 return 0; 1315 return regs->gprs[offset]; 1316 } 1317 1318 int regs_query_register_offset(const char *name) 1319 { 1320 unsigned long offset; 1321 1322 if (!name || *name != 'r') 1323 return -EINVAL; 1324 if (kstrtoul(name + 1, 10, &offset)) 1325 return -EINVAL; 1326 if (offset >= NUM_GPRS) 1327 return -EINVAL; 1328 return offset; 1329 } 1330 1331 const char *regs_query_register_name(unsigned int offset) 1332 { 1333 if (offset >= NUM_GPRS) 1334 return NULL; 1335 return gpr_names[offset]; 1336 } 1337 1338 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr) 1339 { 1340 unsigned long ksp = kernel_stack_pointer(regs); 1341 1342 return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1)); 1343 } 1344 1345 /** 1346 * regs_get_kernel_stack_nth() - get Nth entry of the stack 1347 * @regs:pt_regs which contains kernel stack pointer. 1348 * @n:stack entry number. 1349 * 1350 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which 1351 * is specifined by @regs. If the @n th entry is NOT in the kernel stack, 1352 * this returns 0. 1353 */ 1354 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n) 1355 { 1356 unsigned long addr; 1357 1358 addr = kernel_stack_pointer(regs) + n * sizeof(long); 1359 if (!regs_within_kernel_stack(regs, addr)) 1360 return 0; 1361 return *(unsigned long *)addr; 1362 } 1363