| 1 | /* By Ross Biro 1/23/92 */ |
| 2 | /* |
| 3 | * Pentium III FXSR, SSE support |
| 4 | * Gareth Hughes <gareth@valinux.com>, May 2000 |
| 5 | */ |
| 6 | |
| 7 | #include <linux/kernel.h> |
| 8 | #include <linux/sched.h> |
| 9 | #include <linux/mm.h> |
| 10 | #include <linux/smp.h> |
| 11 | #include <linux/errno.h> |
| 12 | #include <linux/ptrace.h> |
| 13 | #include <linux/user.h> |
| 14 | #include <linux/security.h> |
| 15 | #include <linux/audit.h> |
| 16 | #include <linux/seccomp.h> |
| 17 | #include <linux/signal.h> |
| 18 | |
| 19 | #include <asm/uaccess.h> |
| 20 | #include <asm/pgtable.h> |
| 21 | #include <asm/system.h> |
| 22 | #include <asm/processor.h> |
| 23 | #include <asm/i387.h> |
| 24 | #include <asm/debugreg.h> |
| 25 | #include <asm/ldt.h> |
| 26 | #include <asm/desc.h> |
| 27 | #include <asm/prctl.h> |
| 28 | #include <asm/proto.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 | /* |
| 36 | * Determines which flags the user has access to [1 = access, 0 = no access]. |
| 37 | */ |
| 38 | #define FLAG_MASK_32 ((unsigned long) \ |
| 39 | (X86_EFLAGS_CF | X86_EFLAGS_PF | \ |
| 40 | X86_EFLAGS_AF | X86_EFLAGS_ZF | \ |
| 41 | X86_EFLAGS_SF | X86_EFLAGS_TF | \ |
| 42 | X86_EFLAGS_DF | X86_EFLAGS_OF | \ |
| 43 | X86_EFLAGS_RF | X86_EFLAGS_AC)) |
| 44 | |
| 45 | /* |
| 46 | * Determines whether a value may be installed in a segment register. |
| 47 | */ |
| 48 | static inline bool invalid_selector(u16 value) |
| 49 | { |
| 50 | return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL); |
| 51 | } |
| 52 | |
| 53 | #ifdef CONFIG_X86_32 |
| 54 | |
| 55 | #define FLAG_MASK FLAG_MASK_32 |
| 56 | |
| 57 | static long *pt_regs_access(struct pt_regs *regs, unsigned long regno) |
| 58 | { |
| 59 | BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0); |
| 60 | regno >>= 2; |
| 61 | if (regno > FS) |
| 62 | --regno; |
| 63 | return ®s->bx + regno; |
| 64 | } |
| 65 | |
| 66 | static u16 get_segment_reg(struct task_struct *task, unsigned long offset) |
| 67 | { |
| 68 | /* |
| 69 | * Returning the value truncates it to 16 bits. |
| 70 | */ |
| 71 | unsigned int retval; |
| 72 | if (offset != offsetof(struct user_regs_struct, gs)) |
| 73 | retval = *pt_regs_access(task_pt_regs(task), offset); |
| 74 | else { |
| 75 | retval = task->thread.gs; |
| 76 | if (task == current) |
| 77 | savesegment(gs, retval); |
| 78 | } |
| 79 | return retval; |
| 80 | } |
| 81 | |
| 82 | static int set_segment_reg(struct task_struct *task, |
| 83 | unsigned long offset, u16 value) |
| 84 | { |
| 85 | /* |
| 86 | * The value argument was already truncated to 16 bits. |
| 87 | */ |
| 88 | if (invalid_selector(value)) |
| 89 | return -EIO; |
| 90 | |
| 91 | if (offset != offsetof(struct user_regs_struct, gs)) |
| 92 | *pt_regs_access(task_pt_regs(task), offset) = value; |
| 93 | else { |
| 94 | task->thread.gs = value; |
| 95 | if (task == current) |
| 96 | /* |
| 97 | * The user-mode %gs is not affected by |
| 98 | * kernel entry, so we must update the CPU. |
| 99 | */ |
| 100 | loadsegment(gs, value); |
| 101 | } |
| 102 | |
| 103 | return 0; |
| 104 | } |
| 105 | |
| 106 | static unsigned long debugreg_addr_limit(struct task_struct *task) |
| 107 | { |
| 108 | return TASK_SIZE - 3; |
| 109 | } |
| 110 | |
| 111 | #else /* CONFIG_X86_64 */ |
| 112 | |
| 113 | #define FLAG_MASK (FLAG_MASK_32 | X86_EFLAGS_NT) |
| 114 | |
| 115 | static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset) |
| 116 | { |
| 117 | BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0); |
| 118 | return ®s->r15 + (offset / sizeof(regs->r15)); |
| 119 | } |
| 120 | |
| 121 | static u16 get_segment_reg(struct task_struct *task, unsigned long offset) |
| 122 | { |
| 123 | /* |
| 124 | * Returning the value truncates it to 16 bits. |
| 125 | */ |
| 126 | unsigned int seg; |
| 127 | |
| 128 | switch (offset) { |
| 129 | case offsetof(struct user_regs_struct, fs): |
| 130 | if (task == current) { |
| 131 | /* Older gas can't assemble movq %?s,%r?? */ |
| 132 | asm("movl %%fs,%0" : "=r" (seg)); |
| 133 | return seg; |
| 134 | } |
| 135 | return task->thread.fsindex; |
| 136 | case offsetof(struct user_regs_struct, gs): |
| 137 | if (task == current) { |
| 138 | asm("movl %%gs,%0" : "=r" (seg)); |
| 139 | return seg; |
| 140 | } |
| 141 | return task->thread.gsindex; |
| 142 | case offsetof(struct user_regs_struct, ds): |
| 143 | if (task == current) { |
| 144 | asm("movl %%ds,%0" : "=r" (seg)); |
| 145 | return seg; |
| 146 | } |
| 147 | return task->thread.ds; |
| 148 | case offsetof(struct user_regs_struct, es): |
| 149 | if (task == current) { |
| 150 | asm("movl %%es,%0" : "=r" (seg)); |
| 151 | return seg; |
| 152 | } |
| 153 | return task->thread.es; |
| 154 | |
| 155 | case offsetof(struct user_regs_struct, cs): |
| 156 | case offsetof(struct user_regs_struct, ss): |
| 157 | break; |
| 158 | } |
| 159 | return *pt_regs_access(task_pt_regs(task), offset); |
| 160 | } |
| 161 | |
| 162 | static int set_segment_reg(struct task_struct *task, |
| 163 | unsigned long offset, u16 value) |
| 164 | { |
| 165 | /* |
| 166 | * The value argument was already truncated to 16 bits. |
| 167 | */ |
| 168 | if (invalid_selector(value)) |
| 169 | return -EIO; |
| 170 | |
| 171 | switch (offset) { |
| 172 | case offsetof(struct user_regs_struct,fs): |
| 173 | /* |
| 174 | * If this is setting fs as for normal 64-bit use but |
| 175 | * setting fs_base has implicitly changed it, leave it. |
| 176 | */ |
| 177 | if ((value == FS_TLS_SEL && task->thread.fsindex == 0 && |
| 178 | task->thread.fs != 0) || |
| 179 | (value == 0 && task->thread.fsindex == FS_TLS_SEL && |
| 180 | task->thread.fs == 0)) |
| 181 | break; |
| 182 | task->thread.fsindex = value; |
| 183 | if (task == current) |
| 184 | loadsegment(fs, task->thread.fsindex); |
| 185 | break; |
| 186 | case offsetof(struct user_regs_struct,gs): |
| 187 | /* |
| 188 | * If this is setting gs as for normal 64-bit use but |
| 189 | * setting gs_base has implicitly changed it, leave it. |
| 190 | */ |
| 191 | if ((value == GS_TLS_SEL && task->thread.gsindex == 0 && |
| 192 | task->thread.gs != 0) || |
| 193 | (value == 0 && task->thread.gsindex == GS_TLS_SEL && |
| 194 | task->thread.gs == 0)) |
| 195 | break; |
| 196 | task->thread.gsindex = value; |
| 197 | if (task == current) |
| 198 | load_gs_index(task->thread.gsindex); |
| 199 | break; |
| 200 | case offsetof(struct user_regs_struct,ds): |
| 201 | task->thread.ds = value; |
| 202 | if (task == current) |
| 203 | loadsegment(ds, task->thread.ds); |
| 204 | break; |
| 205 | case offsetof(struct user_regs_struct,es): |
| 206 | task->thread.es = value; |
| 207 | if (task == current) |
| 208 | loadsegment(es, task->thread.es); |
| 209 | break; |
| 210 | |
| 211 | /* |
| 212 | * Can't actually change these in 64-bit mode. |
| 213 | */ |
| 214 | case offsetof(struct user_regs_struct,cs): |
| 215 | #ifdef CONFIG_IA32_EMULATION |
| 216 | if (test_tsk_thread_flag(task, TIF_IA32)) |
| 217 | task_pt_regs(task)->cs = value; |
| 218 | #endif |
| 219 | break; |
| 220 | case offsetof(struct user_regs_struct,ss): |
| 221 | #ifdef CONFIG_IA32_EMULATION |
| 222 | if (test_tsk_thread_flag(task, TIF_IA32)) |
| 223 | task_pt_regs(task)->ss = value; |
| 224 | #endif |
| 225 | break; |
| 226 | } |
| 227 | |
| 228 | return 0; |
| 229 | } |
| 230 | |
| 231 | static unsigned long debugreg_addr_limit(struct task_struct *task) |
| 232 | { |
| 233 | #ifdef CONFIG_IA32_EMULATION |
| 234 | if (test_tsk_thread_flag(task, TIF_IA32)) |
| 235 | return IA32_PAGE_OFFSET - 3; |
| 236 | #endif |
| 237 | return TASK_SIZE64 - 7; |
| 238 | } |
| 239 | |
| 240 | #endif /* CONFIG_X86_32 */ |
| 241 | |
| 242 | static unsigned long get_flags(struct task_struct *task) |
| 243 | { |
| 244 | unsigned long retval = task_pt_regs(task)->flags; |
| 245 | |
| 246 | /* |
| 247 | * If the debugger set TF, hide it from the readout. |
| 248 | */ |
| 249 | if (test_tsk_thread_flag(task, TIF_FORCED_TF)) |
| 250 | retval &= ~X86_EFLAGS_TF; |
| 251 | |
| 252 | return retval; |
| 253 | } |
| 254 | |
| 255 | static int set_flags(struct task_struct *task, unsigned long value) |
| 256 | { |
| 257 | struct pt_regs *regs = task_pt_regs(task); |
| 258 | |
| 259 | /* |
| 260 | * If the user value contains TF, mark that |
| 261 | * it was not "us" (the debugger) that set it. |
| 262 | * If not, make sure it stays set if we had. |
| 263 | */ |
| 264 | if (value & X86_EFLAGS_TF) |
| 265 | clear_tsk_thread_flag(task, TIF_FORCED_TF); |
| 266 | else if (test_tsk_thread_flag(task, TIF_FORCED_TF)) |
| 267 | value |= X86_EFLAGS_TF; |
| 268 | |
| 269 | regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK); |
| 270 | |
| 271 | return 0; |
| 272 | } |
| 273 | |
| 274 | static int putreg(struct task_struct *child, |
| 275 | unsigned long offset, unsigned long value) |
| 276 | { |
| 277 | switch (offset) { |
| 278 | case offsetof(struct user_regs_struct, cs): |
| 279 | case offsetof(struct user_regs_struct, ds): |
| 280 | case offsetof(struct user_regs_struct, es): |
| 281 | case offsetof(struct user_regs_struct, fs): |
| 282 | case offsetof(struct user_regs_struct, gs): |
| 283 | case offsetof(struct user_regs_struct, ss): |
| 284 | return set_segment_reg(child, offset, value); |
| 285 | |
| 286 | case offsetof(struct user_regs_struct, flags): |
| 287 | return set_flags(child, value); |
| 288 | |
| 289 | #ifdef CONFIG_X86_64 |
| 290 | case offsetof(struct user_regs_struct,fs_base): |
| 291 | if (value >= TASK_SIZE_OF(child)) |
| 292 | return -EIO; |
| 293 | /* |
| 294 | * When changing the segment base, use do_arch_prctl |
| 295 | * to set either thread.fs or thread.fsindex and the |
| 296 | * corresponding GDT slot. |
| 297 | */ |
| 298 | if (child->thread.fs != value) |
| 299 | return do_arch_prctl(child, ARCH_SET_FS, value); |
| 300 | return 0; |
| 301 | case offsetof(struct user_regs_struct,gs_base): |
| 302 | /* |
| 303 | * Exactly the same here as the %fs handling above. |
| 304 | */ |
| 305 | if (value >= TASK_SIZE_OF(child)) |
| 306 | return -EIO; |
| 307 | if (child->thread.gs != value) |
| 308 | return do_arch_prctl(child, ARCH_SET_GS, value); |
| 309 | return 0; |
| 310 | #endif |
| 311 | } |
| 312 | |
| 313 | *pt_regs_access(task_pt_regs(child), offset) = value; |
| 314 | return 0; |
| 315 | } |
| 316 | |
| 317 | static unsigned long getreg(struct task_struct *task, unsigned long offset) |
| 318 | { |
| 319 | switch (offset) { |
| 320 | case offsetof(struct user_regs_struct, cs): |
| 321 | case offsetof(struct user_regs_struct, ds): |
| 322 | case offsetof(struct user_regs_struct, es): |
| 323 | case offsetof(struct user_regs_struct, fs): |
| 324 | case offsetof(struct user_regs_struct, gs): |
| 325 | case offsetof(struct user_regs_struct, ss): |
| 326 | return get_segment_reg(task, offset); |
| 327 | |
| 328 | case offsetof(struct user_regs_struct, flags): |
| 329 | return get_flags(task); |
| 330 | |
| 331 | #ifdef CONFIG_X86_64 |
| 332 | case offsetof(struct user_regs_struct, fs_base): { |
| 333 | /* |
| 334 | * do_arch_prctl may have used a GDT slot instead of |
| 335 | * the MSR. To userland, it appears the same either |
| 336 | * way, except the %fs segment selector might not be 0. |
| 337 | */ |
| 338 | unsigned int seg = task->thread.fsindex; |
| 339 | if (task->thread.fs != 0) |
| 340 | return task->thread.fs; |
| 341 | if (task == current) |
| 342 | asm("movl %%fs,%0" : "=r" (seg)); |
| 343 | if (seg != FS_TLS_SEL) |
| 344 | return 0; |
| 345 | return get_desc_base(&task->thread.tls_array[FS_TLS]); |
| 346 | } |
| 347 | case offsetof(struct user_regs_struct, gs_base): { |
| 348 | /* |
| 349 | * Exactly the same here as the %fs handling above. |
| 350 | */ |
| 351 | unsigned int seg = task->thread.gsindex; |
| 352 | if (task->thread.gs != 0) |
| 353 | return task->thread.gs; |
| 354 | if (task == current) |
| 355 | asm("movl %%gs,%0" : "=r" (seg)); |
| 356 | if (seg != GS_TLS_SEL) |
| 357 | return 0; |
| 358 | return get_desc_base(&task->thread.tls_array[GS_TLS]); |
| 359 | } |
| 360 | #endif |
| 361 | } |
| 362 | |
| 363 | return *pt_regs_access(task_pt_regs(task), offset); |
| 364 | } |
| 365 | |
| 366 | /* |
| 367 | * This function is trivial and will be inlined by the compiler. |
| 368 | * Having it separates the implementation details of debug |
| 369 | * registers from the interface details of ptrace. |
| 370 | */ |
| 371 | static unsigned long ptrace_get_debugreg(struct task_struct *child, int n) |
| 372 | { |
| 373 | switch (n) { |
| 374 | case 0: return child->thread.debugreg0; |
| 375 | case 1: return child->thread.debugreg1; |
| 376 | case 2: return child->thread.debugreg2; |
| 377 | case 3: return child->thread.debugreg3; |
| 378 | case 6: return child->thread.debugreg6; |
| 379 | case 7: return child->thread.debugreg7; |
| 380 | } |
| 381 | return 0; |
| 382 | } |
| 383 | |
| 384 | static int ptrace_set_debugreg(struct task_struct *child, |
| 385 | int n, unsigned long data) |
| 386 | { |
| 387 | int i; |
| 388 | |
| 389 | if (unlikely(n == 4 || n == 5)) |
| 390 | return -EIO; |
| 391 | |
| 392 | if (n < 4 && unlikely(data >= debugreg_addr_limit(child))) |
| 393 | return -EIO; |
| 394 | |
| 395 | switch (n) { |
| 396 | case 0: child->thread.debugreg0 = data; break; |
| 397 | case 1: child->thread.debugreg1 = data; break; |
| 398 | case 2: child->thread.debugreg2 = data; break; |
| 399 | case 3: child->thread.debugreg3 = data; break; |
| 400 | |
| 401 | case 6: |
| 402 | if ((data & ~0xffffffffUL) != 0) |
| 403 | return -EIO; |
| 404 | child->thread.debugreg6 = data; |
| 405 | break; |
| 406 | |
| 407 | case 7: |
| 408 | /* |
| 409 | * Sanity-check data. Take one half-byte at once with |
| 410 | * check = (val >> (16 + 4*i)) & 0xf. It contains the |
| 411 | * R/Wi and LENi bits; bits 0 and 1 are R/Wi, and bits |
| 412 | * 2 and 3 are LENi. Given a list of invalid values, |
| 413 | * we do mask |= 1 << invalid_value, so that |
| 414 | * (mask >> check) & 1 is a correct test for invalid |
| 415 | * values. |
| 416 | * |
| 417 | * R/Wi contains the type of the breakpoint / |
| 418 | * watchpoint, LENi contains the length of the watched |
| 419 | * data in the watchpoint case. |
| 420 | * |
| 421 | * The invalid values are: |
| 422 | * - LENi == 0x10 (undefined), so mask |= 0x0f00. [32-bit] |
| 423 | * - R/Wi == 0x10 (break on I/O reads or writes), so |
| 424 | * mask |= 0x4444. |
| 425 | * - R/Wi == 0x00 && LENi != 0x00, so we have mask |= |
| 426 | * 0x1110. |
| 427 | * |
| 428 | * Finally, mask = 0x0f00 | 0x4444 | 0x1110 == 0x5f54. |
| 429 | * |
| 430 | * See the Intel Manual "System Programming Guide", |
| 431 | * 15.2.4 |
| 432 | * |
| 433 | * Note that LENi == 0x10 is defined on x86_64 in long |
| 434 | * mode (i.e. even for 32-bit userspace software, but |
| 435 | * 64-bit kernel), so the x86_64 mask value is 0x5454. |
| 436 | * See the AMD manual no. 24593 (AMD64 System Programming) |
| 437 | */ |
| 438 | #ifdef CONFIG_X86_32 |
| 439 | #define DR7_MASK 0x5f54 |
| 440 | #else |
| 441 | #define DR7_MASK 0x5554 |
| 442 | #endif |
| 443 | data &= ~DR_CONTROL_RESERVED; |
| 444 | for (i = 0; i < 4; i++) |
| 445 | if ((DR7_MASK >> ((data >> (16 + 4*i)) & 0xf)) & 1) |
| 446 | return -EIO; |
| 447 | child->thread.debugreg7 = data; |
| 448 | if (data) |
| 449 | set_tsk_thread_flag(child, TIF_DEBUG); |
| 450 | else |
| 451 | clear_tsk_thread_flag(child, TIF_DEBUG); |
| 452 | break; |
| 453 | } |
| 454 | |
| 455 | return 0; |
| 456 | } |
| 457 | |
| 458 | /* |
| 459 | * Called by kernel/ptrace.c when detaching.. |
| 460 | * |
| 461 | * Make sure the single step bit is not set. |
| 462 | */ |
| 463 | void ptrace_disable(struct task_struct *child) |
| 464 | { |
| 465 | user_disable_single_step(child); |
| 466 | #ifdef TIF_SYSCALL_EMU |
| 467 | clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); |
| 468 | #endif |
| 469 | } |
| 470 | |
| 471 | long arch_ptrace(struct task_struct *child, long request, long addr, long data) |
| 472 | { |
| 473 | int i, ret; |
| 474 | unsigned long __user *datap = (unsigned long __user *)data; |
| 475 | |
| 476 | switch (request) { |
| 477 | /* when I and D space are separate, these will need to be fixed. */ |
| 478 | case PTRACE_PEEKTEXT: /* read word at location addr. */ |
| 479 | case PTRACE_PEEKDATA: |
| 480 | ret = generic_ptrace_peekdata(child, addr, data); |
| 481 | break; |
| 482 | |
| 483 | /* read the word at location addr in the USER area. */ |
| 484 | case PTRACE_PEEKUSR: { |
| 485 | unsigned long tmp; |
| 486 | |
| 487 | ret = -EIO; |
| 488 | if ((addr & (sizeof(data) - 1)) || addr < 0 || |
| 489 | addr >= sizeof(struct user)) |
| 490 | break; |
| 491 | |
| 492 | tmp = 0; /* Default return condition */ |
| 493 | if (addr < sizeof(struct user_regs_struct)) |
| 494 | tmp = getreg(child, addr); |
| 495 | else if (addr >= offsetof(struct user, u_debugreg[0]) && |
| 496 | addr <= offsetof(struct user, u_debugreg[7])) { |
| 497 | addr -= offsetof(struct user, u_debugreg[0]); |
| 498 | tmp = ptrace_get_debugreg(child, addr / sizeof(data)); |
| 499 | } |
| 500 | ret = put_user(tmp, datap); |
| 501 | break; |
| 502 | } |
| 503 | |
| 504 | /* when I and D space are separate, this will have to be fixed. */ |
| 505 | case PTRACE_POKETEXT: /* write the word at location addr. */ |
| 506 | case PTRACE_POKEDATA: |
| 507 | ret = generic_ptrace_pokedata(child, addr, data); |
| 508 | break; |
| 509 | |
| 510 | case PTRACE_POKEUSR: /* write the word at location addr in the USER area */ |
| 511 | ret = -EIO; |
| 512 | if ((addr & (sizeof(data) - 1)) || addr < 0 || |
| 513 | addr >= sizeof(struct user)) |
| 514 | break; |
| 515 | |
| 516 | if (addr < sizeof(struct user_regs_struct)) |
| 517 | ret = putreg(child, addr, data); |
| 518 | else if (addr >= offsetof(struct user, u_debugreg[0]) && |
| 519 | addr <= offsetof(struct user, u_debugreg[7])) { |
| 520 | addr -= offsetof(struct user, u_debugreg[0]); |
| 521 | ret = ptrace_set_debugreg(child, |
| 522 | addr / sizeof(data), data); |
| 523 | } |
| 524 | break; |
| 525 | |
| 526 | case PTRACE_GETREGS: { /* Get all gp regs from the child. */ |
| 527 | if (!access_ok(VERIFY_WRITE, datap, sizeof(struct user_regs_struct))) { |
| 528 | ret = -EIO; |
| 529 | break; |
| 530 | } |
| 531 | for (i = 0; i < sizeof(struct user_regs_struct); i += sizeof(long)) { |
| 532 | __put_user(getreg(child, i), datap); |
| 533 | datap++; |
| 534 | } |
| 535 | ret = 0; |
| 536 | break; |
| 537 | } |
| 538 | |
| 539 | case PTRACE_SETREGS: { /* Set all gp regs in the child. */ |
| 540 | unsigned long tmp; |
| 541 | if (!access_ok(VERIFY_READ, datap, sizeof(struct user_regs_struct))) { |
| 542 | ret = -EIO; |
| 543 | break; |
| 544 | } |
| 545 | for (i = 0; i < sizeof(struct user_regs_struct); i += sizeof(long)) { |
| 546 | __get_user(tmp, datap); |
| 547 | putreg(child, i, tmp); |
| 548 | datap++; |
| 549 | } |
| 550 | ret = 0; |
| 551 | break; |
| 552 | } |
| 553 | |
| 554 | case PTRACE_GETFPREGS: { /* Get the child FPU state. */ |
| 555 | if (!access_ok(VERIFY_WRITE, datap, |
| 556 | sizeof(struct user_i387_struct))) { |
| 557 | ret = -EIO; |
| 558 | break; |
| 559 | } |
| 560 | ret = 0; |
| 561 | if (!tsk_used_math(child)) |
| 562 | init_fpu(child); |
| 563 | get_fpregs((struct user_i387_struct __user *)data, child); |
| 564 | break; |
| 565 | } |
| 566 | |
| 567 | case PTRACE_SETFPREGS: { /* Set the child FPU state. */ |
| 568 | if (!access_ok(VERIFY_READ, datap, |
| 569 | sizeof(struct user_i387_struct))) { |
| 570 | ret = -EIO; |
| 571 | break; |
| 572 | } |
| 573 | set_stopped_child_used_math(child); |
| 574 | set_fpregs(child, (struct user_i387_struct __user *)data); |
| 575 | ret = 0; |
| 576 | break; |
| 577 | } |
| 578 | |
| 579 | #ifdef CONFIG_X86_32 |
| 580 | case PTRACE_GETFPXREGS: { /* Get the child extended FPU state. */ |
| 581 | if (!access_ok(VERIFY_WRITE, datap, |
| 582 | sizeof(struct user_fxsr_struct))) { |
| 583 | ret = -EIO; |
| 584 | break; |
| 585 | } |
| 586 | if (!tsk_used_math(child)) |
| 587 | init_fpu(child); |
| 588 | ret = get_fpxregs((struct user_fxsr_struct __user *)data, child); |
| 589 | break; |
| 590 | } |
| 591 | |
| 592 | case PTRACE_SETFPXREGS: { /* Set the child extended FPU state. */ |
| 593 | if (!access_ok(VERIFY_READ, datap, |
| 594 | sizeof(struct user_fxsr_struct))) { |
| 595 | ret = -EIO; |
| 596 | break; |
| 597 | } |
| 598 | set_stopped_child_used_math(child); |
| 599 | ret = set_fpxregs(child, (struct user_fxsr_struct __user *)data); |
| 600 | break; |
| 601 | } |
| 602 | #endif |
| 603 | |
| 604 | #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION |
| 605 | case PTRACE_GET_THREAD_AREA: |
| 606 | if (addr < 0) |
| 607 | return -EIO; |
| 608 | ret = do_get_thread_area(child, addr, |
| 609 | (struct user_desc __user *) data); |
| 610 | break; |
| 611 | |
| 612 | case PTRACE_SET_THREAD_AREA: |
| 613 | if (addr < 0) |
| 614 | return -EIO; |
| 615 | ret = do_set_thread_area(child, addr, |
| 616 | (struct user_desc __user *) data, 0); |
| 617 | break; |
| 618 | #endif |
| 619 | |
| 620 | #ifdef CONFIG_X86_64 |
| 621 | /* normal 64bit interface to access TLS data. |
| 622 | Works just like arch_prctl, except that the arguments |
| 623 | are reversed. */ |
| 624 | case PTRACE_ARCH_PRCTL: |
| 625 | ret = do_arch_prctl(child, data, addr); |
| 626 | break; |
| 627 | #endif |
| 628 | |
| 629 | default: |
| 630 | ret = ptrace_request(child, request, addr, data); |
| 631 | break; |
| 632 | } |
| 633 | |
| 634 | return ret; |
| 635 | } |
| 636 | |
| 637 | #ifdef CONFIG_IA32_EMULATION |
| 638 | |
| 639 | #include <asm/user32.h> |
| 640 | |
| 641 | #define R32(l,q) \ |
| 642 | case offsetof(struct user32, regs.l): \ |
| 643 | regs->q = value; break |
| 644 | |
| 645 | #define SEG32(rs) \ |
| 646 | case offsetof(struct user32, regs.rs): \ |
| 647 | return set_segment_reg(child, \ |
| 648 | offsetof(struct user_regs_struct, rs), \ |
| 649 | value); \ |
| 650 | break |
| 651 | |
| 652 | static int putreg32(struct task_struct *child, unsigned regno, u32 value) |
| 653 | { |
| 654 | struct pt_regs *regs = task_pt_regs(child); |
| 655 | |
| 656 | switch (regno) { |
| 657 | |
| 658 | SEG32(cs); |
| 659 | SEG32(ds); |
| 660 | SEG32(es); |
| 661 | SEG32(fs); |
| 662 | SEG32(gs); |
| 663 | SEG32(ss); |
| 664 | |
| 665 | R32(ebx, bx); |
| 666 | R32(ecx, cx); |
| 667 | R32(edx, dx); |
| 668 | R32(edi, di); |
| 669 | R32(esi, si); |
| 670 | R32(ebp, bp); |
| 671 | R32(eax, ax); |
| 672 | R32(orig_eax, orig_ax); |
| 673 | R32(eip, ip); |
| 674 | R32(esp, sp); |
| 675 | |
| 676 | case offsetof(struct user32, regs.eflags): |
| 677 | return set_flags(child, value); |
| 678 | |
| 679 | case offsetof(struct user32, u_debugreg[0]) ... |
| 680 | offsetof(struct user32, u_debugreg[7]): |
| 681 | regno -= offsetof(struct user32, u_debugreg[0]); |
| 682 | return ptrace_set_debugreg(child, regno / 4, value); |
| 683 | |
| 684 | default: |
| 685 | if (regno > sizeof(struct user32) || (regno & 3)) |
| 686 | return -EIO; |
| 687 | |
| 688 | /* |
| 689 | * Other dummy fields in the virtual user structure |
| 690 | * are ignored |
| 691 | */ |
| 692 | break; |
| 693 | } |
| 694 | return 0; |
| 695 | } |
| 696 | |
| 697 | #undef R32 |
| 698 | #undef SEG32 |
| 699 | |
| 700 | #define R32(l,q) \ |
| 701 | case offsetof(struct user32, regs.l): \ |
| 702 | *val = regs->q; break |
| 703 | |
| 704 | #define SEG32(rs) \ |
| 705 | case offsetof(struct user32, regs.rs): \ |
| 706 | *val = get_segment_reg(child, \ |
| 707 | offsetof(struct user_regs_struct, rs)); \ |
| 708 | break |
| 709 | |
| 710 | static int getreg32(struct task_struct *child, unsigned regno, u32 *val) |
| 711 | { |
| 712 | struct pt_regs *regs = task_pt_regs(child); |
| 713 | |
| 714 | switch (regno) { |
| 715 | |
| 716 | SEG32(ds); |
| 717 | SEG32(es); |
| 718 | SEG32(fs); |
| 719 | SEG32(gs); |
| 720 | |
| 721 | R32(cs, cs); |
| 722 | R32(ss, ss); |
| 723 | R32(ebx, bx); |
| 724 | R32(ecx, cx); |
| 725 | R32(edx, dx); |
| 726 | R32(edi, di); |
| 727 | R32(esi, si); |
| 728 | R32(ebp, bp); |
| 729 | R32(eax, ax); |
| 730 | R32(orig_eax, orig_ax); |
| 731 | R32(eip, ip); |
| 732 | R32(esp, sp); |
| 733 | |
| 734 | case offsetof(struct user32, regs.eflags): |
| 735 | *val = get_flags(child); |
| 736 | break; |
| 737 | |
| 738 | case offsetof(struct user32, u_debugreg[0]) ... |
| 739 | offsetof(struct user32, u_debugreg[7]): |
| 740 | regno -= offsetof(struct user32, u_debugreg[0]); |
| 741 | *val = ptrace_get_debugreg(child, regno / 4); |
| 742 | break; |
| 743 | |
| 744 | default: |
| 745 | if (regno > sizeof(struct user32) || (regno & 3)) |
| 746 | return -EIO; |
| 747 | |
| 748 | /* |
| 749 | * Other dummy fields in the virtual user structure |
| 750 | * are ignored |
| 751 | */ |
| 752 | *val = 0; |
| 753 | break; |
| 754 | } |
| 755 | return 0; |
| 756 | } |
| 757 | |
| 758 | #undef R32 |
| 759 | #undef SEG32 |
| 760 | |
| 761 | #endif /* CONFIG_IA32_EMULATION */ |
| 762 | |
| 763 | #ifdef CONFIG_X86_32 |
| 764 | |
| 765 | void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code) |
| 766 | { |
| 767 | struct siginfo info; |
| 768 | |
| 769 | tsk->thread.trap_no = 1; |
| 770 | tsk->thread.error_code = error_code; |
| 771 | |
| 772 | memset(&info, 0, sizeof(info)); |
| 773 | info.si_signo = SIGTRAP; |
| 774 | info.si_code = TRAP_BRKPT; |
| 775 | |
| 776 | /* User-mode ip? */ |
| 777 | info.si_addr = user_mode_vm(regs) ? (void __user *) regs->ip : NULL; |
| 778 | |
| 779 | /* Send us the fake SIGTRAP */ |
| 780 | force_sig_info(SIGTRAP, &info, tsk); |
| 781 | } |
| 782 | |
| 783 | /* notification of system call entry/exit |
| 784 | * - triggered by current->work.syscall_trace |
| 785 | */ |
| 786 | __attribute__((regparm(3))) |
| 787 | int do_syscall_trace(struct pt_regs *regs, int entryexit) |
| 788 | { |
| 789 | int is_sysemu = test_thread_flag(TIF_SYSCALL_EMU); |
| 790 | /* |
| 791 | * With TIF_SYSCALL_EMU set we want to ignore TIF_SINGLESTEP for syscall |
| 792 | * interception |
| 793 | */ |
| 794 | int is_singlestep = !is_sysemu && test_thread_flag(TIF_SINGLESTEP); |
| 795 | int ret = 0; |
| 796 | |
| 797 | /* do the secure computing check first */ |
| 798 | if (!entryexit) |
| 799 | secure_computing(regs->orig_ax); |
| 800 | |
| 801 | if (unlikely(current->audit_context)) { |
| 802 | if (entryexit) |
| 803 | audit_syscall_exit(AUDITSC_RESULT(regs->ax), |
| 804 | regs->ax); |
| 805 | /* Debug traps, when using PTRACE_SINGLESTEP, must be sent only |
| 806 | * on the syscall exit path. Normally, when TIF_SYSCALL_AUDIT is |
| 807 | * not used, entry.S will call us only on syscall exit, not |
| 808 | * entry; so when TIF_SYSCALL_AUDIT is used we must avoid |
| 809 | * calling send_sigtrap() on syscall entry. |
| 810 | * |
| 811 | * Note that when PTRACE_SYSEMU_SINGLESTEP is used, |
| 812 | * is_singlestep is false, despite his name, so we will still do |
| 813 | * the correct thing. |
| 814 | */ |
| 815 | else if (is_singlestep) |
| 816 | goto out; |
| 817 | } |
| 818 | |
| 819 | if (!(current->ptrace & PT_PTRACED)) |
| 820 | goto out; |
| 821 | |
| 822 | /* If a process stops on the 1st tracepoint with SYSCALL_TRACE |
| 823 | * and then is resumed with SYSEMU_SINGLESTEP, it will come in |
| 824 | * here. We have to check this and return */ |
| 825 | if (is_sysemu && entryexit) |
| 826 | return 0; |
| 827 | |
| 828 | /* Fake a debug trap */ |
| 829 | if (is_singlestep) |
| 830 | send_sigtrap(current, regs, 0); |
| 831 | |
| 832 | if (!test_thread_flag(TIF_SYSCALL_TRACE) && !is_sysemu) |
| 833 | goto out; |
| 834 | |
| 835 | /* the 0x80 provides a way for the tracing parent to distinguish |
| 836 | between a syscall stop and SIGTRAP delivery */ |
| 837 | /* Note that the debugger could change the result of test_thread_flag!*/ |
| 838 | ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) ? 0x80:0)); |
| 839 | |
| 840 | /* |
| 841 | * this isn't the same as continuing with a signal, but it will do |
| 842 | * for normal use. strace only continues with a signal if the |
| 843 | * stopping signal is not SIGTRAP. -brl |
| 844 | */ |
| 845 | if (current->exit_code) { |
| 846 | send_sig(current->exit_code, current, 1); |
| 847 | current->exit_code = 0; |
| 848 | } |
| 849 | ret = is_sysemu; |
| 850 | out: |
| 851 | if (unlikely(current->audit_context) && !entryexit) |
| 852 | audit_syscall_entry(AUDIT_ARCH_I386, regs->orig_ax, |
| 853 | regs->bx, regs->cx, regs->dx, regs->si); |
| 854 | if (ret == 0) |
| 855 | return 0; |
| 856 | |
| 857 | regs->orig_ax = -1; /* force skip of syscall restarting */ |
| 858 | if (unlikely(current->audit_context)) |
| 859 | audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax); |
| 860 | return 1; |
| 861 | } |
| 862 | |
| 863 | #else /* CONFIG_X86_64 */ |
| 864 | |
| 865 | static void syscall_trace(struct pt_regs *regs) |
| 866 | { |
| 867 | |
| 868 | #if 0 |
| 869 | printk("trace %s ip %lx sp %lx ax %d origrax %d caller %lx tiflags %x ptrace %x\n", |
| 870 | current->comm, |
| 871 | regs->ip, regs->sp, regs->ax, regs->orig_ax, __builtin_return_address(0), |
| 872 | current_thread_info()->flags, current->ptrace); |
| 873 | #endif |
| 874 | |
| 875 | ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) |
| 876 | ? 0x80 : 0)); |
| 877 | /* |
| 878 | * this isn't the same as continuing with a signal, but it will do |
| 879 | * for normal use. strace only continues with a signal if the |
| 880 | * stopping signal is not SIGTRAP. -brl |
| 881 | */ |
| 882 | if (current->exit_code) { |
| 883 | send_sig(current->exit_code, current, 1); |
| 884 | current->exit_code = 0; |
| 885 | } |
| 886 | } |
| 887 | |
| 888 | asmlinkage void syscall_trace_enter(struct pt_regs *regs) |
| 889 | { |
| 890 | /* do the secure computing check first */ |
| 891 | secure_computing(regs->orig_ax); |
| 892 | |
| 893 | if (test_thread_flag(TIF_SYSCALL_TRACE) |
| 894 | && (current->ptrace & PT_PTRACED)) |
| 895 | syscall_trace(regs); |
| 896 | |
| 897 | if (unlikely(current->audit_context)) { |
| 898 | if (test_thread_flag(TIF_IA32)) { |
| 899 | audit_syscall_entry(AUDIT_ARCH_I386, |
| 900 | regs->orig_ax, |
| 901 | regs->bx, regs->cx, |
| 902 | regs->dx, regs->si); |
| 903 | } else { |
| 904 | audit_syscall_entry(AUDIT_ARCH_X86_64, |
| 905 | regs->orig_ax, |
| 906 | regs->di, regs->si, |
| 907 | regs->dx, regs->r10); |
| 908 | } |
| 909 | } |
| 910 | } |
| 911 | |
| 912 | asmlinkage void syscall_trace_leave(struct pt_regs *regs) |
| 913 | { |
| 914 | if (unlikely(current->audit_context)) |
| 915 | audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax); |
| 916 | |
| 917 | if ((test_thread_flag(TIF_SYSCALL_TRACE) |
| 918 | || test_thread_flag(TIF_SINGLESTEP)) |
| 919 | && (current->ptrace & PT_PTRACED)) |
| 920 | syscall_trace(regs); |
| 921 | } |
| 922 | |
| 923 | #endif /* CONFIG_X86_32 */ |