Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* ptrace.c */ |
| 2 | /* By Ross Biro 1/23/92 */ |
| 3 | /* |
| 4 | * Pentium III FXSR, SSE support |
| 5 | * Gareth Hughes <gareth@valinux.com>, May 2000 |
| 6 | */ |
| 7 | |
| 8 | #include <linux/kernel.h> |
| 9 | #include <linux/sched.h> |
| 10 | #include <linux/mm.h> |
| 11 | #include <linux/smp.h> |
| 12 | #include <linux/smp_lock.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/seccomp.h> |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 19 | #include <linux/signal.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 20 | |
| 21 | #include <asm/uaccess.h> |
| 22 | #include <asm/pgtable.h> |
| 23 | #include <asm/system.h> |
| 24 | #include <asm/processor.h> |
| 25 | #include <asm/i387.h> |
| 26 | #include <asm/debugreg.h> |
| 27 | #include <asm/ldt.h> |
| 28 | #include <asm/desc.h> |
| 29 | |
| 30 | /* |
| 31 | * does not yet catch signals sent when the child dies. |
| 32 | * in exit.c or in signal.c. |
| 33 | */ |
| 34 | |
| 35 | /* determines which flags the user has access to. */ |
| 36 | /* 1 = access 0 = no access */ |
| 37 | #define FLAG_MASK 0x00044dd5 |
| 38 | |
| 39 | /* set's the trap flag. */ |
| 40 | #define TRAP_FLAG 0x100 |
| 41 | |
| 42 | /* |
| 43 | * Offset of eflags on child stack.. |
| 44 | */ |
| 45 | #define EFL_OFFSET ((EFL-2)*4-sizeof(struct pt_regs)) |
| 46 | |
| 47 | static inline struct pt_regs *get_child_regs(struct task_struct *task) |
| 48 | { |
| 49 | void *stack_top = (void *)task->thread.esp0; |
| 50 | return stack_top - sizeof(struct pt_regs); |
| 51 | } |
| 52 | |
| 53 | /* |
| 54 | * this routine will get a word off of the processes privileged stack. |
| 55 | * the offset is how far from the base addr as stored in the TSS. |
| 56 | * this routine assumes that all the privileged stacks are in our |
| 57 | * data space. |
| 58 | */ |
| 59 | static inline int get_stack_long(struct task_struct *task, int offset) |
| 60 | { |
| 61 | unsigned char *stack; |
| 62 | |
| 63 | stack = (unsigned char *)task->thread.esp0; |
| 64 | stack += offset; |
| 65 | return (*((int *)stack)); |
| 66 | } |
| 67 | |
| 68 | /* |
| 69 | * this routine will put a word on the processes privileged stack. |
| 70 | * the offset is how far from the base addr as stored in the TSS. |
| 71 | * this routine assumes that all the privileged stacks are in our |
| 72 | * data space. |
| 73 | */ |
| 74 | static inline int put_stack_long(struct task_struct *task, int offset, |
| 75 | unsigned long data) |
| 76 | { |
| 77 | unsigned char * stack; |
| 78 | |
| 79 | stack = (unsigned char *) task->thread.esp0; |
| 80 | stack += offset; |
| 81 | *(unsigned long *) stack = data; |
| 82 | return 0; |
| 83 | } |
| 84 | |
| 85 | static int putreg(struct task_struct *child, |
| 86 | unsigned long regno, unsigned long value) |
| 87 | { |
| 88 | switch (regno >> 2) { |
| 89 | case FS: |
| 90 | if (value && (value & 3) != 3) |
| 91 | return -EIO; |
| 92 | child->thread.fs = value; |
| 93 | return 0; |
| 94 | case GS: |
| 95 | if (value && (value & 3) != 3) |
| 96 | return -EIO; |
| 97 | child->thread.gs = value; |
| 98 | return 0; |
| 99 | case DS: |
| 100 | case ES: |
| 101 | if (value && (value & 3) != 3) |
| 102 | return -EIO; |
| 103 | value &= 0xffff; |
| 104 | break; |
| 105 | case SS: |
| 106 | case CS: |
| 107 | if ((value & 3) != 3) |
| 108 | return -EIO; |
| 109 | value &= 0xffff; |
| 110 | break; |
| 111 | case EFL: |
| 112 | value &= FLAG_MASK; |
| 113 | value |= get_stack_long(child, EFL_OFFSET) & ~FLAG_MASK; |
| 114 | break; |
| 115 | } |
| 116 | if (regno > GS*4) |
| 117 | regno -= 2*4; |
| 118 | put_stack_long(child, regno - sizeof(struct pt_regs), value); |
| 119 | return 0; |
| 120 | } |
| 121 | |
| 122 | static unsigned long getreg(struct task_struct *child, |
| 123 | unsigned long regno) |
| 124 | { |
| 125 | unsigned long retval = ~0UL; |
| 126 | |
| 127 | switch (regno >> 2) { |
| 128 | case FS: |
| 129 | retval = child->thread.fs; |
| 130 | break; |
| 131 | case GS: |
| 132 | retval = child->thread.gs; |
| 133 | break; |
| 134 | case DS: |
| 135 | case ES: |
| 136 | case SS: |
| 137 | case CS: |
| 138 | retval = 0xffff; |
| 139 | /* fall through */ |
| 140 | default: |
| 141 | if (regno > GS*4) |
| 142 | regno -= 2*4; |
| 143 | regno = regno - sizeof(struct pt_regs); |
| 144 | retval &= get_stack_long(child, regno); |
| 145 | } |
| 146 | return retval; |
| 147 | } |
| 148 | |
| 149 | #define LDT_SEGMENT 4 |
| 150 | |
| 151 | static unsigned long convert_eip_to_linear(struct task_struct *child, struct pt_regs *regs) |
| 152 | { |
| 153 | unsigned long addr, seg; |
| 154 | |
| 155 | addr = regs->eip; |
| 156 | seg = regs->xcs & 0xffff; |
| 157 | if (regs->eflags & VM_MASK) { |
| 158 | addr = (addr & 0xffff) + (seg << 4); |
| 159 | return addr; |
| 160 | } |
| 161 | |
| 162 | /* |
| 163 | * We'll assume that the code segments in the GDT |
| 164 | * are all zero-based. That is largely true: the |
| 165 | * TLS segments are used for data, and the PNPBIOS |
| 166 | * and APM bios ones we just ignore here. |
| 167 | */ |
| 168 | if (seg & LDT_SEGMENT) { |
| 169 | u32 *desc; |
| 170 | unsigned long base; |
| 171 | |
| 172 | down(&child->mm->context.sem); |
| 173 | desc = child->mm->context.ldt + (seg & ~7); |
| 174 | base = (desc[0] >> 16) | ((desc[1] & 0xff) << 16) | (desc[1] & 0xff000000); |
| 175 | |
| 176 | /* 16-bit code segment? */ |
| 177 | if (!((desc[1] >> 22) & 1)) |
| 178 | addr &= 0xffff; |
| 179 | addr += base; |
| 180 | up(&child->mm->context.sem); |
| 181 | } |
| 182 | return addr; |
| 183 | } |
| 184 | |
| 185 | static inline int is_at_popf(struct task_struct *child, struct pt_regs *regs) |
| 186 | { |
| 187 | int i, copied; |
| 188 | unsigned char opcode[16]; |
| 189 | unsigned long addr = convert_eip_to_linear(child, regs); |
| 190 | |
| 191 | copied = access_process_vm(child, addr, opcode, sizeof(opcode), 0); |
| 192 | for (i = 0; i < copied; i++) { |
| 193 | switch (opcode[i]) { |
| 194 | /* popf */ |
| 195 | case 0x9d: |
| 196 | return 1; |
| 197 | /* opcode and address size prefixes */ |
| 198 | case 0x66: case 0x67: |
| 199 | continue; |
| 200 | /* irrelevant prefixes (segment overrides and repeats) */ |
| 201 | case 0x26: case 0x2e: |
| 202 | case 0x36: case 0x3e: |
| 203 | case 0x64: case 0x65: |
| 204 | case 0xf0: case 0xf2: case 0xf3: |
| 205 | continue; |
| 206 | |
| 207 | /* |
| 208 | * pushf: NOTE! We should probably not let |
| 209 | * the user see the TF bit being set. But |
| 210 | * it's more pain than it's worth to avoid |
| 211 | * it, and a debugger could emulate this |
| 212 | * all in user space if it _really_ cares. |
| 213 | */ |
| 214 | case 0x9c: |
| 215 | default: |
| 216 | return 0; |
| 217 | } |
| 218 | } |
| 219 | return 0; |
| 220 | } |
| 221 | |
| 222 | static void set_singlestep(struct task_struct *child) |
| 223 | { |
| 224 | struct pt_regs *regs = get_child_regs(child); |
| 225 | |
| 226 | /* |
| 227 | * Always set TIF_SINGLESTEP - this guarantees that |
| 228 | * we single-step system calls etc.. This will also |
| 229 | * cause us to set TF when returning to user mode. |
| 230 | */ |
| 231 | set_tsk_thread_flag(child, TIF_SINGLESTEP); |
| 232 | |
| 233 | /* |
| 234 | * If TF was already set, don't do anything else |
| 235 | */ |
| 236 | if (regs->eflags & TRAP_FLAG) |
| 237 | return; |
| 238 | |
| 239 | /* Set TF on the kernel stack.. */ |
| 240 | regs->eflags |= TRAP_FLAG; |
| 241 | |
| 242 | /* |
| 243 | * ..but if TF is changed by the instruction we will trace, |
| 244 | * don't mark it as being "us" that set it, so that we |
| 245 | * won't clear it by hand later. |
| 246 | */ |
| 247 | if (is_at_popf(child, regs)) |
| 248 | return; |
| 249 | |
| 250 | child->ptrace |= PT_DTRACE; |
| 251 | } |
| 252 | |
| 253 | static void clear_singlestep(struct task_struct *child) |
| 254 | { |
| 255 | /* Always clear TIF_SINGLESTEP... */ |
| 256 | clear_tsk_thread_flag(child, TIF_SINGLESTEP); |
| 257 | |
| 258 | /* But touch TF only if it was set by us.. */ |
| 259 | if (child->ptrace & PT_DTRACE) { |
| 260 | struct pt_regs *regs = get_child_regs(child); |
| 261 | regs->eflags &= ~TRAP_FLAG; |
| 262 | child->ptrace &= ~PT_DTRACE; |
| 263 | } |
| 264 | } |
| 265 | |
| 266 | /* |
| 267 | * Called by kernel/ptrace.c when detaching.. |
| 268 | * |
| 269 | * Make sure the single step bit is not set. |
| 270 | */ |
| 271 | void ptrace_disable(struct task_struct *child) |
| 272 | { |
| 273 | clear_singlestep(child); |
| 274 | } |
| 275 | |
| 276 | /* |
| 277 | * Perform get_thread_area on behalf of the traced child. |
| 278 | */ |
| 279 | static int |
| 280 | ptrace_get_thread_area(struct task_struct *child, |
| 281 | int idx, struct user_desc __user *user_desc) |
| 282 | { |
| 283 | struct user_desc info; |
| 284 | struct desc_struct *desc; |
| 285 | |
| 286 | /* |
| 287 | * Get the current Thread-Local Storage area: |
| 288 | */ |
| 289 | |
| 290 | #define GET_BASE(desc) ( \ |
| 291 | (((desc)->a >> 16) & 0x0000ffff) | \ |
| 292 | (((desc)->b << 16) & 0x00ff0000) | \ |
| 293 | ( (desc)->b & 0xff000000) ) |
| 294 | |
| 295 | #define GET_LIMIT(desc) ( \ |
| 296 | ((desc)->a & 0x0ffff) | \ |
| 297 | ((desc)->b & 0xf0000) ) |
| 298 | |
| 299 | #define GET_32BIT(desc) (((desc)->b >> 22) & 1) |
| 300 | #define GET_CONTENTS(desc) (((desc)->b >> 10) & 3) |
| 301 | #define GET_WRITABLE(desc) (((desc)->b >> 9) & 1) |
| 302 | #define GET_LIMIT_PAGES(desc) (((desc)->b >> 23) & 1) |
| 303 | #define GET_PRESENT(desc) (((desc)->b >> 15) & 1) |
| 304 | #define GET_USEABLE(desc) (((desc)->b >> 20) & 1) |
| 305 | |
| 306 | if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX) |
| 307 | return -EINVAL; |
| 308 | |
| 309 | desc = child->thread.tls_array + idx - GDT_ENTRY_TLS_MIN; |
| 310 | |
| 311 | info.entry_number = idx; |
| 312 | info.base_addr = GET_BASE(desc); |
| 313 | info.limit = GET_LIMIT(desc); |
| 314 | info.seg_32bit = GET_32BIT(desc); |
| 315 | info.contents = GET_CONTENTS(desc); |
| 316 | info.read_exec_only = !GET_WRITABLE(desc); |
| 317 | info.limit_in_pages = GET_LIMIT_PAGES(desc); |
| 318 | info.seg_not_present = !GET_PRESENT(desc); |
| 319 | info.useable = GET_USEABLE(desc); |
| 320 | |
| 321 | if (copy_to_user(user_desc, &info, sizeof(info))) |
| 322 | return -EFAULT; |
| 323 | |
| 324 | return 0; |
| 325 | } |
| 326 | |
| 327 | /* |
| 328 | * Perform set_thread_area on behalf of the traced child. |
| 329 | */ |
| 330 | static int |
| 331 | ptrace_set_thread_area(struct task_struct *child, |
| 332 | int idx, struct user_desc __user *user_desc) |
| 333 | { |
| 334 | struct user_desc info; |
| 335 | struct desc_struct *desc; |
| 336 | |
| 337 | if (copy_from_user(&info, user_desc, sizeof(info))) |
| 338 | return -EFAULT; |
| 339 | |
| 340 | if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX) |
| 341 | return -EINVAL; |
| 342 | |
| 343 | desc = child->thread.tls_array + idx - GDT_ENTRY_TLS_MIN; |
| 344 | if (LDT_empty(&info)) { |
| 345 | desc->a = 0; |
| 346 | desc->b = 0; |
| 347 | } else { |
| 348 | desc->a = LDT_entry_a(&info); |
| 349 | desc->b = LDT_entry_b(&info); |
| 350 | } |
| 351 | |
| 352 | return 0; |
| 353 | } |
| 354 | |
| 355 | asmlinkage int sys_ptrace(long request, long pid, long addr, long data) |
| 356 | { |
| 357 | struct task_struct *child; |
| 358 | struct user * dummy = NULL; |
| 359 | int i, ret; |
| 360 | unsigned long __user *datap = (unsigned long __user *)data; |
| 361 | |
| 362 | lock_kernel(); |
| 363 | ret = -EPERM; |
| 364 | if (request == PTRACE_TRACEME) { |
| 365 | /* are we already being traced? */ |
| 366 | if (current->ptrace & PT_PTRACED) |
| 367 | goto out; |
| 368 | ret = security_ptrace(current->parent, current); |
| 369 | if (ret) |
| 370 | goto out; |
| 371 | /* set the ptrace bit in the process flags. */ |
| 372 | current->ptrace |= PT_PTRACED; |
| 373 | ret = 0; |
| 374 | goto out; |
| 375 | } |
| 376 | ret = -ESRCH; |
| 377 | read_lock(&tasklist_lock); |
| 378 | child = find_task_by_pid(pid); |
| 379 | if (child) |
| 380 | get_task_struct(child); |
| 381 | read_unlock(&tasklist_lock); |
| 382 | if (!child) |
| 383 | goto out; |
| 384 | |
| 385 | ret = -EPERM; |
| 386 | if (pid == 1) /* you may not mess with init */ |
| 387 | goto out_tsk; |
| 388 | |
| 389 | if (request == PTRACE_ATTACH) { |
| 390 | ret = ptrace_attach(child); |
| 391 | goto out_tsk; |
| 392 | } |
| 393 | |
| 394 | ret = ptrace_check_attach(child, request == PTRACE_KILL); |
| 395 | if (ret < 0) |
| 396 | goto out_tsk; |
| 397 | |
| 398 | switch (request) { |
| 399 | /* when I and D space are separate, these will need to be fixed. */ |
| 400 | case PTRACE_PEEKTEXT: /* read word at location addr. */ |
| 401 | case PTRACE_PEEKDATA: { |
| 402 | unsigned long tmp; |
| 403 | int copied; |
| 404 | |
| 405 | copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0); |
| 406 | ret = -EIO; |
| 407 | if (copied != sizeof(tmp)) |
| 408 | break; |
| 409 | ret = put_user(tmp, datap); |
| 410 | break; |
| 411 | } |
| 412 | |
| 413 | /* read the word at location addr in the USER area. */ |
| 414 | case PTRACE_PEEKUSR: { |
| 415 | unsigned long tmp; |
| 416 | |
| 417 | ret = -EIO; |
| 418 | if ((addr & 3) || addr < 0 || |
| 419 | addr > sizeof(struct user) - 3) |
| 420 | break; |
| 421 | |
| 422 | tmp = 0; /* Default return condition */ |
| 423 | if(addr < FRAME_SIZE*sizeof(long)) |
| 424 | tmp = getreg(child, addr); |
| 425 | if(addr >= (long) &dummy->u_debugreg[0] && |
| 426 | addr <= (long) &dummy->u_debugreg[7]){ |
| 427 | addr -= (long) &dummy->u_debugreg[0]; |
| 428 | addr = addr >> 2; |
| 429 | tmp = child->thread.debugreg[addr]; |
| 430 | } |
| 431 | ret = put_user(tmp, datap); |
| 432 | break; |
| 433 | } |
| 434 | |
| 435 | /* when I and D space are separate, this will have to be fixed. */ |
| 436 | case PTRACE_POKETEXT: /* write the word at location addr. */ |
| 437 | case PTRACE_POKEDATA: |
| 438 | ret = 0; |
| 439 | if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data)) |
| 440 | break; |
| 441 | ret = -EIO; |
| 442 | break; |
| 443 | |
| 444 | case PTRACE_POKEUSR: /* write the word at location addr in the USER area */ |
| 445 | ret = -EIO; |
| 446 | if ((addr & 3) || addr < 0 || |
| 447 | addr > sizeof(struct user) - 3) |
| 448 | break; |
| 449 | |
| 450 | if (addr < FRAME_SIZE*sizeof(long)) { |
| 451 | ret = putreg(child, addr, data); |
| 452 | break; |
| 453 | } |
| 454 | /* We need to be very careful here. We implicitly |
| 455 | want to modify a portion of the task_struct, and we |
| 456 | have to be selective about what portions we allow someone |
| 457 | to modify. */ |
| 458 | |
| 459 | ret = -EIO; |
| 460 | if(addr >= (long) &dummy->u_debugreg[0] && |
| 461 | addr <= (long) &dummy->u_debugreg[7]){ |
| 462 | |
| 463 | if(addr == (long) &dummy->u_debugreg[4]) break; |
| 464 | if(addr == (long) &dummy->u_debugreg[5]) break; |
| 465 | if(addr < (long) &dummy->u_debugreg[4] && |
| 466 | ((unsigned long) data) >= TASK_SIZE-3) break; |
| 467 | |
| 468 | /* Sanity-check data. Take one half-byte at once with |
| 469 | * check = (val >> (16 + 4*i)) & 0xf. It contains the |
| 470 | * R/Wi and LENi bits; bits 0 and 1 are R/Wi, and bits |
| 471 | * 2 and 3 are LENi. Given a list of invalid values, |
| 472 | * we do mask |= 1 << invalid_value, so that |
| 473 | * (mask >> check) & 1 is a correct test for invalid |
| 474 | * values. |
| 475 | * |
| 476 | * R/Wi contains the type of the breakpoint / |
| 477 | * watchpoint, LENi contains the length of the watched |
| 478 | * data in the watchpoint case. |
| 479 | * |
| 480 | * The invalid values are: |
| 481 | * - LENi == 0x10 (undefined), so mask |= 0x0f00. |
| 482 | * - R/Wi == 0x10 (break on I/O reads or writes), so |
| 483 | * mask |= 0x4444. |
| 484 | * - R/Wi == 0x00 && LENi != 0x00, so we have mask |= |
| 485 | * 0x1110. |
| 486 | * |
| 487 | * Finally, mask = 0x0f00 | 0x4444 | 0x1110 == 0x5f54. |
| 488 | * |
| 489 | * See the Intel Manual "System Programming Guide", |
| 490 | * 15.2.4 |
| 491 | * |
| 492 | * Note that LENi == 0x10 is defined on x86_64 in long |
| 493 | * mode (i.e. even for 32-bit userspace software, but |
| 494 | * 64-bit kernel), so the x86_64 mask value is 0x5454. |
| 495 | * See the AMD manual no. 24593 (AMD64 System |
| 496 | * Programming)*/ |
| 497 | |
| 498 | if(addr == (long) &dummy->u_debugreg[7]) { |
| 499 | data &= ~DR_CONTROL_RESERVED; |
| 500 | for(i=0; i<4; i++) |
| 501 | if ((0x5f54 >> ((data >> (16 + 4*i)) & 0xf)) & 1) |
| 502 | goto out_tsk; |
| 503 | } |
| 504 | |
| 505 | addr -= (long) &dummy->u_debugreg; |
| 506 | addr = addr >> 2; |
| 507 | child->thread.debugreg[addr] = data; |
| 508 | ret = 0; |
| 509 | } |
| 510 | break; |
| 511 | |
| 512 | case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ |
| 513 | case PTRACE_CONT: /* restart after signal. */ |
| 514 | ret = -EIO; |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 515 | if (!valid_signal(data)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 516 | break; |
| 517 | if (request == PTRACE_SYSCALL) { |
| 518 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
| 519 | } |
| 520 | else { |
| 521 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
| 522 | } |
| 523 | child->exit_code = data; |
| 524 | /* make sure the single step bit is not set. */ |
| 525 | clear_singlestep(child); |
| 526 | wake_up_process(child); |
| 527 | ret = 0; |
| 528 | break; |
| 529 | |
| 530 | /* |
| 531 | * make the child exit. Best I can do is send it a sigkill. |
| 532 | * perhaps it should be put in the status that it wants to |
| 533 | * exit. |
| 534 | */ |
| 535 | case PTRACE_KILL: |
| 536 | ret = 0; |
| 537 | if (child->exit_state == EXIT_ZOMBIE) /* already dead */ |
| 538 | break; |
| 539 | child->exit_code = SIGKILL; |
| 540 | /* make sure the single step bit is not set. */ |
| 541 | clear_singlestep(child); |
| 542 | wake_up_process(child); |
| 543 | break; |
| 544 | |
| 545 | case PTRACE_SINGLESTEP: /* set the trap flag. */ |
| 546 | ret = -EIO; |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 547 | if (!valid_signal(data)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 548 | break; |
| 549 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
| 550 | set_singlestep(child); |
| 551 | child->exit_code = data; |
| 552 | /* give it a chance to run. */ |
| 553 | wake_up_process(child); |
| 554 | ret = 0; |
| 555 | break; |
| 556 | |
| 557 | case PTRACE_DETACH: |
| 558 | /* detach a process that was attached. */ |
| 559 | ret = ptrace_detach(child, data); |
| 560 | break; |
| 561 | |
| 562 | case PTRACE_GETREGS: { /* Get all gp regs from the child. */ |
| 563 | if (!access_ok(VERIFY_WRITE, datap, FRAME_SIZE*sizeof(long))) { |
| 564 | ret = -EIO; |
| 565 | break; |
| 566 | } |
| 567 | for ( i = 0; i < FRAME_SIZE*sizeof(long); i += sizeof(long) ) { |
| 568 | __put_user(getreg(child, i), datap); |
| 569 | datap++; |
| 570 | } |
| 571 | ret = 0; |
| 572 | break; |
| 573 | } |
| 574 | |
| 575 | case PTRACE_SETREGS: { /* Set all gp regs in the child. */ |
| 576 | unsigned long tmp; |
| 577 | if (!access_ok(VERIFY_READ, datap, FRAME_SIZE*sizeof(long))) { |
| 578 | ret = -EIO; |
| 579 | break; |
| 580 | } |
| 581 | for ( i = 0; i < FRAME_SIZE*sizeof(long); i += sizeof(long) ) { |
| 582 | __get_user(tmp, datap); |
| 583 | putreg(child, i, tmp); |
| 584 | datap++; |
| 585 | } |
| 586 | ret = 0; |
| 587 | break; |
| 588 | } |
| 589 | |
| 590 | case PTRACE_GETFPREGS: { /* Get the child FPU state. */ |
| 591 | if (!access_ok(VERIFY_WRITE, datap, |
| 592 | sizeof(struct user_i387_struct))) { |
| 593 | ret = -EIO; |
| 594 | break; |
| 595 | } |
| 596 | ret = 0; |
| 597 | if (!tsk_used_math(child)) |
| 598 | init_fpu(child); |
| 599 | get_fpregs((struct user_i387_struct __user *)data, child); |
| 600 | break; |
| 601 | } |
| 602 | |
| 603 | case PTRACE_SETFPREGS: { /* Set the child FPU state. */ |
| 604 | if (!access_ok(VERIFY_READ, datap, |
| 605 | sizeof(struct user_i387_struct))) { |
| 606 | ret = -EIO; |
| 607 | break; |
| 608 | } |
| 609 | set_stopped_child_used_math(child); |
| 610 | set_fpregs(child, (struct user_i387_struct __user *)data); |
| 611 | ret = 0; |
| 612 | break; |
| 613 | } |
| 614 | |
| 615 | case PTRACE_GETFPXREGS: { /* Get the child extended FPU state. */ |
| 616 | if (!access_ok(VERIFY_WRITE, datap, |
| 617 | sizeof(struct user_fxsr_struct))) { |
| 618 | ret = -EIO; |
| 619 | break; |
| 620 | } |
| 621 | if (!tsk_used_math(child)) |
| 622 | init_fpu(child); |
| 623 | ret = get_fpxregs((struct user_fxsr_struct __user *)data, child); |
| 624 | break; |
| 625 | } |
| 626 | |
| 627 | case PTRACE_SETFPXREGS: { /* Set the child extended FPU state. */ |
| 628 | if (!access_ok(VERIFY_READ, datap, |
| 629 | sizeof(struct user_fxsr_struct))) { |
| 630 | ret = -EIO; |
| 631 | break; |
| 632 | } |
| 633 | set_stopped_child_used_math(child); |
| 634 | ret = set_fpxregs(child, (struct user_fxsr_struct __user *)data); |
| 635 | break; |
| 636 | } |
| 637 | |
| 638 | case PTRACE_GET_THREAD_AREA: |
| 639 | ret = ptrace_get_thread_area(child, addr, |
| 640 | (struct user_desc __user *) data); |
| 641 | break; |
| 642 | |
| 643 | case PTRACE_SET_THREAD_AREA: |
| 644 | ret = ptrace_set_thread_area(child, addr, |
| 645 | (struct user_desc __user *) data); |
| 646 | break; |
| 647 | |
| 648 | default: |
| 649 | ret = ptrace_request(child, request, addr, data); |
| 650 | break; |
| 651 | } |
| 652 | out_tsk: |
| 653 | put_task_struct(child); |
| 654 | out: |
| 655 | unlock_kernel(); |
| 656 | return ret; |
| 657 | } |
| 658 | |
| 659 | void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code) |
| 660 | { |
| 661 | struct siginfo info; |
| 662 | |
| 663 | tsk->thread.trap_no = 1; |
| 664 | tsk->thread.error_code = error_code; |
| 665 | |
| 666 | memset(&info, 0, sizeof(info)); |
| 667 | info.si_signo = SIGTRAP; |
| 668 | info.si_code = TRAP_BRKPT; |
| 669 | |
| 670 | /* User-mode eip? */ |
| 671 | info.si_addr = user_mode(regs) ? (void __user *) regs->eip : NULL; |
| 672 | |
| 673 | /* Send us the fakey SIGTRAP */ |
| 674 | force_sig_info(SIGTRAP, &info, tsk); |
| 675 | } |
| 676 | |
| 677 | /* notification of system call entry/exit |
| 678 | * - triggered by current->work.syscall_trace |
| 679 | */ |
| 680 | __attribute__((regparm(3))) |
| 681 | void do_syscall_trace(struct pt_regs *regs, int entryexit) |
| 682 | { |
| 683 | /* do the secure computing check first */ |
| 684 | secure_computing(regs->orig_eax); |
| 685 | |
| 2fd6f58 | 2005-04-29 16:08:28 +0100 | [diff] [blame] | 686 | if (unlikely(current->audit_context) && entryexit) |
| 687 | audit_syscall_exit(current, AUDITSC_RESULT(regs->eax), regs->eax); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 688 | |
| 689 | if (!(current->ptrace & PT_PTRACED)) |
| 2fd6f58 | 2005-04-29 16:08:28 +0100 | [diff] [blame] | 690 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 691 | |
| 692 | /* Fake a debug trap */ |
| 693 | if (test_thread_flag(TIF_SINGLESTEP)) |
| 694 | send_sigtrap(current, regs, 0); |
| 695 | |
| 696 | if (!test_thread_flag(TIF_SYSCALL_TRACE)) |
| 2fd6f58 | 2005-04-29 16:08:28 +0100 | [diff] [blame] | 697 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 698 | |
| 699 | /* the 0x80 provides a way for the tracing parent to distinguish |
| 700 | between a syscall stop and SIGTRAP delivery */ |
| 701 | ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) ? 0x80 : 0)); |
| 702 | |
| 703 | /* |
| 704 | * this isn't the same as continuing with a signal, but it will do |
| 705 | * for normal use. strace only continues with a signal if the |
| 706 | * stopping signal is not SIGTRAP. -brl |
| 707 | */ |
| 708 | if (current->exit_code) { |
| 709 | send_sig(current->exit_code, current, 1); |
| 710 | current->exit_code = 0; |
| 711 | } |
| 2fd6f58 | 2005-04-29 16:08:28 +0100 | [diff] [blame] | 712 | out: |
| 713 | if (unlikely(current->audit_context) && !entryexit) |
| 714 | audit_syscall_entry(current, AUDIT_ARCH_I386, regs->orig_eax, |
| 715 | regs->ebx, regs->ecx, regs->edx, regs->esi); |
| 716 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 717 | } |