| 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/slab.h> |
| 13 | #include <linux/ptrace.h> |
| 14 | #include <linux/regset.h> |
| 15 | #include <linux/tracehook.h> |
| 16 | #include <linux/user.h> |
| 17 | #include <linux/elf.h> |
| 18 | #include <linux/security.h> |
| 19 | #include <linux/audit.h> |
| 20 | #include <linux/seccomp.h> |
| 21 | #include <linux/signal.h> |
| 22 | #include <linux/perf_event.h> |
| 23 | #include <linux/hw_breakpoint.h> |
| 24 | #include <linux/rcupdate.h> |
| 25 | #include <linux/export.h> |
| 26 | #include <linux/context_tracking.h> |
| 27 | |
| 28 | #include <asm/uaccess.h> |
| 29 | #include <asm/pgtable.h> |
| 30 | #include <asm/processor.h> |
| 31 | #include <asm/fpu/internal.h> |
| 32 | #include <asm/debugreg.h> |
| 33 | #include <asm/ldt.h> |
| 34 | #include <asm/desc.h> |
| 35 | #include <asm/prctl.h> |
| 36 | #include <asm/proto.h> |
| 37 | #include <asm/hw_breakpoint.h> |
| 38 | #include <asm/traps.h> |
| 39 | |
| 40 | #include "tls.h" |
| 41 | |
| 42 | #define CREATE_TRACE_POINTS |
| 43 | #include <trace/events/syscalls.h> |
| 44 | |
| 45 | enum x86_regset { |
| 46 | REGSET_GENERAL, |
| 47 | REGSET_FP, |
| 48 | REGSET_XFP, |
| 49 | REGSET_IOPERM64 = REGSET_XFP, |
| 50 | REGSET_XSTATE, |
| 51 | REGSET_TLS, |
| 52 | REGSET_IOPERM32, |
| 53 | }; |
| 54 | |
| 55 | struct pt_regs_offset { |
| 56 | const char *name; |
| 57 | int offset; |
| 58 | }; |
| 59 | |
| 60 | #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)} |
| 61 | #define REG_OFFSET_END {.name = NULL, .offset = 0} |
| 62 | |
| 63 | static const struct pt_regs_offset regoffset_table[] = { |
| 64 | #ifdef CONFIG_X86_64 |
| 65 | REG_OFFSET_NAME(r15), |
| 66 | REG_OFFSET_NAME(r14), |
| 67 | REG_OFFSET_NAME(r13), |
| 68 | REG_OFFSET_NAME(r12), |
| 69 | REG_OFFSET_NAME(r11), |
| 70 | REG_OFFSET_NAME(r10), |
| 71 | REG_OFFSET_NAME(r9), |
| 72 | REG_OFFSET_NAME(r8), |
| 73 | #endif |
| 74 | REG_OFFSET_NAME(bx), |
| 75 | REG_OFFSET_NAME(cx), |
| 76 | REG_OFFSET_NAME(dx), |
| 77 | REG_OFFSET_NAME(si), |
| 78 | REG_OFFSET_NAME(di), |
| 79 | REG_OFFSET_NAME(bp), |
| 80 | REG_OFFSET_NAME(ax), |
| 81 | #ifdef CONFIG_X86_32 |
| 82 | REG_OFFSET_NAME(ds), |
| 83 | REG_OFFSET_NAME(es), |
| 84 | REG_OFFSET_NAME(fs), |
| 85 | REG_OFFSET_NAME(gs), |
| 86 | #endif |
| 87 | REG_OFFSET_NAME(orig_ax), |
| 88 | REG_OFFSET_NAME(ip), |
| 89 | REG_OFFSET_NAME(cs), |
| 90 | REG_OFFSET_NAME(flags), |
| 91 | REG_OFFSET_NAME(sp), |
| 92 | REG_OFFSET_NAME(ss), |
| 93 | REG_OFFSET_END, |
| 94 | }; |
| 95 | |
| 96 | /** |
| 97 | * regs_query_register_offset() - query register offset from its name |
| 98 | * @name: the name of a register |
| 99 | * |
| 100 | * regs_query_register_offset() returns the offset of a register in struct |
| 101 | * pt_regs from its name. If the name is invalid, this returns -EINVAL; |
| 102 | */ |
| 103 | int regs_query_register_offset(const char *name) |
| 104 | { |
| 105 | const struct pt_regs_offset *roff; |
| 106 | for (roff = regoffset_table; roff->name != NULL; roff++) |
| 107 | if (!strcmp(roff->name, name)) |
| 108 | return roff->offset; |
| 109 | return -EINVAL; |
| 110 | } |
| 111 | |
| 112 | /** |
| 113 | * regs_query_register_name() - query register name from its offset |
| 114 | * @offset: the offset of a register in struct pt_regs. |
| 115 | * |
| 116 | * regs_query_register_name() returns the name of a register from its |
| 117 | * offset in struct pt_regs. If the @offset is invalid, this returns NULL; |
| 118 | */ |
| 119 | const char *regs_query_register_name(unsigned int offset) |
| 120 | { |
| 121 | const struct pt_regs_offset *roff; |
| 122 | for (roff = regoffset_table; roff->name != NULL; roff++) |
| 123 | if (roff->offset == offset) |
| 124 | return roff->name; |
| 125 | return NULL; |
| 126 | } |
| 127 | |
| 128 | static const int arg_offs_table[] = { |
| 129 | #ifdef CONFIG_X86_32 |
| 130 | [0] = offsetof(struct pt_regs, ax), |
| 131 | [1] = offsetof(struct pt_regs, dx), |
| 132 | [2] = offsetof(struct pt_regs, cx) |
| 133 | #else /* CONFIG_X86_64 */ |
| 134 | [0] = offsetof(struct pt_regs, di), |
| 135 | [1] = offsetof(struct pt_regs, si), |
| 136 | [2] = offsetof(struct pt_regs, dx), |
| 137 | [3] = offsetof(struct pt_regs, cx), |
| 138 | [4] = offsetof(struct pt_regs, r8), |
| 139 | [5] = offsetof(struct pt_regs, r9) |
| 140 | #endif |
| 141 | }; |
| 142 | |
| 143 | /* |
| 144 | * does not yet catch signals sent when the child dies. |
| 145 | * in exit.c or in signal.c. |
| 146 | */ |
| 147 | |
| 148 | /* |
| 149 | * Determines which flags the user has access to [1 = access, 0 = no access]. |
| 150 | */ |
| 151 | #define FLAG_MASK_32 ((unsigned long) \ |
| 152 | (X86_EFLAGS_CF | X86_EFLAGS_PF | \ |
| 153 | X86_EFLAGS_AF | X86_EFLAGS_ZF | \ |
| 154 | X86_EFLAGS_SF | X86_EFLAGS_TF | \ |
| 155 | X86_EFLAGS_DF | X86_EFLAGS_OF | \ |
| 156 | X86_EFLAGS_RF | X86_EFLAGS_AC)) |
| 157 | |
| 158 | /* |
| 159 | * Determines whether a value may be installed in a segment register. |
| 160 | */ |
| 161 | static inline bool invalid_selector(u16 value) |
| 162 | { |
| 163 | return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL); |
| 164 | } |
| 165 | |
| 166 | #ifdef CONFIG_X86_32 |
| 167 | |
| 168 | #define FLAG_MASK FLAG_MASK_32 |
| 169 | |
| 170 | /* |
| 171 | * X86_32 CPUs don't save ss and esp if the CPU is already in kernel mode |
| 172 | * when it traps. The previous stack will be directly underneath the saved |
| 173 | * registers, and 'sp/ss' won't even have been saved. Thus the '®s->sp'. |
| 174 | * |
| 175 | * Now, if the stack is empty, '®s->sp' is out of range. In this |
| 176 | * case we try to take the previous stack. To always return a non-null |
| 177 | * stack pointer we fall back to regs as stack if no previous stack |
| 178 | * exists. |
| 179 | * |
| 180 | * This is valid only for kernel mode traps. |
| 181 | */ |
| 182 | unsigned long kernel_stack_pointer(struct pt_regs *regs) |
| 183 | { |
| 184 | unsigned long context = (unsigned long)regs & ~(THREAD_SIZE - 1); |
| 185 | unsigned long sp = (unsigned long)®s->sp; |
| 186 | u32 *prev_esp; |
| 187 | |
| 188 | if (context == (sp & ~(THREAD_SIZE - 1))) |
| 189 | return sp; |
| 190 | |
| 191 | prev_esp = (u32 *)(context); |
| 192 | if (prev_esp) |
| 193 | return (unsigned long)prev_esp; |
| 194 | |
| 195 | return (unsigned long)regs; |
| 196 | } |
| 197 | EXPORT_SYMBOL_GPL(kernel_stack_pointer); |
| 198 | |
| 199 | static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno) |
| 200 | { |
| 201 | BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0); |
| 202 | return ®s->bx + (regno >> 2); |
| 203 | } |
| 204 | |
| 205 | static u16 get_segment_reg(struct task_struct *task, unsigned long offset) |
| 206 | { |
| 207 | /* |
| 208 | * Returning the value truncates it to 16 bits. |
| 209 | */ |
| 210 | unsigned int retval; |
| 211 | if (offset != offsetof(struct user_regs_struct, gs)) |
| 212 | retval = *pt_regs_access(task_pt_regs(task), offset); |
| 213 | else { |
| 214 | if (task == current) |
| 215 | retval = get_user_gs(task_pt_regs(task)); |
| 216 | else |
| 217 | retval = task_user_gs(task); |
| 218 | } |
| 219 | return retval; |
| 220 | } |
| 221 | |
| 222 | static int set_segment_reg(struct task_struct *task, |
| 223 | unsigned long offset, u16 value) |
| 224 | { |
| 225 | /* |
| 226 | * The value argument was already truncated to 16 bits. |
| 227 | */ |
| 228 | if (invalid_selector(value)) |
| 229 | return -EIO; |
| 230 | |
| 231 | /* |
| 232 | * For %cs and %ss we cannot permit a null selector. |
| 233 | * We can permit a bogus selector as long as it has USER_RPL. |
| 234 | * Null selectors are fine for other segment registers, but |
| 235 | * we will never get back to user mode with invalid %cs or %ss |
| 236 | * and will take the trap in iret instead. Much code relies |
| 237 | * on user_mode() to distinguish a user trap frame (which can |
| 238 | * safely use invalid selectors) from a kernel trap frame. |
| 239 | */ |
| 240 | switch (offset) { |
| 241 | case offsetof(struct user_regs_struct, cs): |
| 242 | case offsetof(struct user_regs_struct, ss): |
| 243 | if (unlikely(value == 0)) |
| 244 | return -EIO; |
| 245 | |
| 246 | default: |
| 247 | *pt_regs_access(task_pt_regs(task), offset) = value; |
| 248 | break; |
| 249 | |
| 250 | case offsetof(struct user_regs_struct, gs): |
| 251 | if (task == current) |
| 252 | set_user_gs(task_pt_regs(task), value); |
| 253 | else |
| 254 | task_user_gs(task) = value; |
| 255 | } |
| 256 | |
| 257 | return 0; |
| 258 | } |
| 259 | |
| 260 | #else /* CONFIG_X86_64 */ |
| 261 | |
| 262 | #define FLAG_MASK (FLAG_MASK_32 | X86_EFLAGS_NT) |
| 263 | |
| 264 | static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset) |
| 265 | { |
| 266 | BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0); |
| 267 | return ®s->r15 + (offset / sizeof(regs->r15)); |
| 268 | } |
| 269 | |
| 270 | static u16 get_segment_reg(struct task_struct *task, unsigned long offset) |
| 271 | { |
| 272 | /* |
| 273 | * Returning the value truncates it to 16 bits. |
| 274 | */ |
| 275 | unsigned int seg; |
| 276 | |
| 277 | switch (offset) { |
| 278 | case offsetof(struct user_regs_struct, fs): |
| 279 | if (task == current) { |
| 280 | /* Older gas can't assemble movq %?s,%r?? */ |
| 281 | asm("movl %%fs,%0" : "=r" (seg)); |
| 282 | return seg; |
| 283 | } |
| 284 | return task->thread.fsindex; |
| 285 | case offsetof(struct user_regs_struct, gs): |
| 286 | if (task == current) { |
| 287 | asm("movl %%gs,%0" : "=r" (seg)); |
| 288 | return seg; |
| 289 | } |
| 290 | return task->thread.gsindex; |
| 291 | case offsetof(struct user_regs_struct, ds): |
| 292 | if (task == current) { |
| 293 | asm("movl %%ds,%0" : "=r" (seg)); |
| 294 | return seg; |
| 295 | } |
| 296 | return task->thread.ds; |
| 297 | case offsetof(struct user_regs_struct, es): |
| 298 | if (task == current) { |
| 299 | asm("movl %%es,%0" : "=r" (seg)); |
| 300 | return seg; |
| 301 | } |
| 302 | return task->thread.es; |
| 303 | |
| 304 | case offsetof(struct user_regs_struct, cs): |
| 305 | case offsetof(struct user_regs_struct, ss): |
| 306 | break; |
| 307 | } |
| 308 | return *pt_regs_access(task_pt_regs(task), offset); |
| 309 | } |
| 310 | |
| 311 | static int set_segment_reg(struct task_struct *task, |
| 312 | unsigned long offset, u16 value) |
| 313 | { |
| 314 | /* |
| 315 | * The value argument was already truncated to 16 bits. |
| 316 | */ |
| 317 | if (invalid_selector(value)) |
| 318 | return -EIO; |
| 319 | |
| 320 | switch (offset) { |
| 321 | case offsetof(struct user_regs_struct,fs): |
| 322 | /* |
| 323 | * If this is setting fs as for normal 64-bit use but |
| 324 | * setting fs_base has implicitly changed it, leave it. |
| 325 | */ |
| 326 | if ((value == FS_TLS_SEL && task->thread.fsindex == 0 && |
| 327 | task->thread.fs != 0) || |
| 328 | (value == 0 && task->thread.fsindex == FS_TLS_SEL && |
| 329 | task->thread.fs == 0)) |
| 330 | break; |
| 331 | task->thread.fsindex = value; |
| 332 | if (task == current) |
| 333 | loadsegment(fs, task->thread.fsindex); |
| 334 | break; |
| 335 | case offsetof(struct user_regs_struct,gs): |
| 336 | /* |
| 337 | * If this is setting gs as for normal 64-bit use but |
| 338 | * setting gs_base has implicitly changed it, leave it. |
| 339 | */ |
| 340 | if ((value == GS_TLS_SEL && task->thread.gsindex == 0 && |
| 341 | task->thread.gs != 0) || |
| 342 | (value == 0 && task->thread.gsindex == GS_TLS_SEL && |
| 343 | task->thread.gs == 0)) |
| 344 | break; |
| 345 | task->thread.gsindex = value; |
| 346 | if (task == current) |
| 347 | load_gs_index(task->thread.gsindex); |
| 348 | break; |
| 349 | case offsetof(struct user_regs_struct,ds): |
| 350 | task->thread.ds = value; |
| 351 | if (task == current) |
| 352 | loadsegment(ds, task->thread.ds); |
| 353 | break; |
| 354 | case offsetof(struct user_regs_struct,es): |
| 355 | task->thread.es = value; |
| 356 | if (task == current) |
| 357 | loadsegment(es, task->thread.es); |
| 358 | break; |
| 359 | |
| 360 | /* |
| 361 | * Can't actually change these in 64-bit mode. |
| 362 | */ |
| 363 | case offsetof(struct user_regs_struct,cs): |
| 364 | if (unlikely(value == 0)) |
| 365 | return -EIO; |
| 366 | task_pt_regs(task)->cs = value; |
| 367 | break; |
| 368 | case offsetof(struct user_regs_struct,ss): |
| 369 | if (unlikely(value == 0)) |
| 370 | return -EIO; |
| 371 | task_pt_regs(task)->ss = value; |
| 372 | break; |
| 373 | } |
| 374 | |
| 375 | return 0; |
| 376 | } |
| 377 | |
| 378 | #endif /* CONFIG_X86_32 */ |
| 379 | |
| 380 | static unsigned long get_flags(struct task_struct *task) |
| 381 | { |
| 382 | unsigned long retval = task_pt_regs(task)->flags; |
| 383 | |
| 384 | /* |
| 385 | * If the debugger set TF, hide it from the readout. |
| 386 | */ |
| 387 | if (test_tsk_thread_flag(task, TIF_FORCED_TF)) |
| 388 | retval &= ~X86_EFLAGS_TF; |
| 389 | |
| 390 | return retval; |
| 391 | } |
| 392 | |
| 393 | static int set_flags(struct task_struct *task, unsigned long value) |
| 394 | { |
| 395 | struct pt_regs *regs = task_pt_regs(task); |
| 396 | |
| 397 | /* |
| 398 | * If the user value contains TF, mark that |
| 399 | * it was not "us" (the debugger) that set it. |
| 400 | * If not, make sure it stays set if we had. |
| 401 | */ |
| 402 | if (value & X86_EFLAGS_TF) |
| 403 | clear_tsk_thread_flag(task, TIF_FORCED_TF); |
| 404 | else if (test_tsk_thread_flag(task, TIF_FORCED_TF)) |
| 405 | value |= X86_EFLAGS_TF; |
| 406 | |
| 407 | regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK); |
| 408 | |
| 409 | return 0; |
| 410 | } |
| 411 | |
| 412 | static int putreg(struct task_struct *child, |
| 413 | unsigned long offset, unsigned long value) |
| 414 | { |
| 415 | switch (offset) { |
| 416 | case offsetof(struct user_regs_struct, cs): |
| 417 | case offsetof(struct user_regs_struct, ds): |
| 418 | case offsetof(struct user_regs_struct, es): |
| 419 | case offsetof(struct user_regs_struct, fs): |
| 420 | case offsetof(struct user_regs_struct, gs): |
| 421 | case offsetof(struct user_regs_struct, ss): |
| 422 | return set_segment_reg(child, offset, value); |
| 423 | |
| 424 | case offsetof(struct user_regs_struct, flags): |
| 425 | return set_flags(child, value); |
| 426 | |
| 427 | #ifdef CONFIG_X86_64 |
| 428 | case offsetof(struct user_regs_struct,fs_base): |
| 429 | if (value >= TASK_SIZE_OF(child)) |
| 430 | return -EIO; |
| 431 | /* |
| 432 | * When changing the segment base, use do_arch_prctl |
| 433 | * to set either thread.fs or thread.fsindex and the |
| 434 | * corresponding GDT slot. |
| 435 | */ |
| 436 | if (child->thread.fs != value) |
| 437 | return do_arch_prctl(child, ARCH_SET_FS, value); |
| 438 | return 0; |
| 439 | case offsetof(struct user_regs_struct,gs_base): |
| 440 | /* |
| 441 | * Exactly the same here as the %fs handling above. |
| 442 | */ |
| 443 | if (value >= TASK_SIZE_OF(child)) |
| 444 | return -EIO; |
| 445 | if (child->thread.gs != value) |
| 446 | return do_arch_prctl(child, ARCH_SET_GS, value); |
| 447 | return 0; |
| 448 | #endif |
| 449 | } |
| 450 | |
| 451 | *pt_regs_access(task_pt_regs(child), offset) = value; |
| 452 | return 0; |
| 453 | } |
| 454 | |
| 455 | static unsigned long getreg(struct task_struct *task, unsigned long offset) |
| 456 | { |
| 457 | switch (offset) { |
| 458 | case offsetof(struct user_regs_struct, cs): |
| 459 | case offsetof(struct user_regs_struct, ds): |
| 460 | case offsetof(struct user_regs_struct, es): |
| 461 | case offsetof(struct user_regs_struct, fs): |
| 462 | case offsetof(struct user_regs_struct, gs): |
| 463 | case offsetof(struct user_regs_struct, ss): |
| 464 | return get_segment_reg(task, offset); |
| 465 | |
| 466 | case offsetof(struct user_regs_struct, flags): |
| 467 | return get_flags(task); |
| 468 | |
| 469 | #ifdef CONFIG_X86_64 |
| 470 | case offsetof(struct user_regs_struct, fs_base): { |
| 471 | /* |
| 472 | * do_arch_prctl may have used a GDT slot instead of |
| 473 | * the MSR. To userland, it appears the same either |
| 474 | * way, except the %fs segment selector might not be 0. |
| 475 | */ |
| 476 | unsigned int seg = task->thread.fsindex; |
| 477 | if (task->thread.fs != 0) |
| 478 | return task->thread.fs; |
| 479 | if (task == current) |
| 480 | asm("movl %%fs,%0" : "=r" (seg)); |
| 481 | if (seg != FS_TLS_SEL) |
| 482 | return 0; |
| 483 | return get_desc_base(&task->thread.tls_array[FS_TLS]); |
| 484 | } |
| 485 | case offsetof(struct user_regs_struct, gs_base): { |
| 486 | /* |
| 487 | * Exactly the same here as the %fs handling above. |
| 488 | */ |
| 489 | unsigned int seg = task->thread.gsindex; |
| 490 | if (task->thread.gs != 0) |
| 491 | return task->thread.gs; |
| 492 | if (task == current) |
| 493 | asm("movl %%gs,%0" : "=r" (seg)); |
| 494 | if (seg != GS_TLS_SEL) |
| 495 | return 0; |
| 496 | return get_desc_base(&task->thread.tls_array[GS_TLS]); |
| 497 | } |
| 498 | #endif |
| 499 | } |
| 500 | |
| 501 | return *pt_regs_access(task_pt_regs(task), offset); |
| 502 | } |
| 503 | |
| 504 | static int genregs_get(struct task_struct *target, |
| 505 | const struct user_regset *regset, |
| 506 | unsigned int pos, unsigned int count, |
| 507 | void *kbuf, void __user *ubuf) |
| 508 | { |
| 509 | if (kbuf) { |
| 510 | unsigned long *k = kbuf; |
| 511 | while (count >= sizeof(*k)) { |
| 512 | *k++ = getreg(target, pos); |
| 513 | count -= sizeof(*k); |
| 514 | pos += sizeof(*k); |
| 515 | } |
| 516 | } else { |
| 517 | unsigned long __user *u = ubuf; |
| 518 | while (count >= sizeof(*u)) { |
| 519 | if (__put_user(getreg(target, pos), u++)) |
| 520 | return -EFAULT; |
| 521 | count -= sizeof(*u); |
| 522 | pos += sizeof(*u); |
| 523 | } |
| 524 | } |
| 525 | |
| 526 | return 0; |
| 527 | } |
| 528 | |
| 529 | static int genregs_set(struct task_struct *target, |
| 530 | const struct user_regset *regset, |
| 531 | unsigned int pos, unsigned int count, |
| 532 | const void *kbuf, const void __user *ubuf) |
| 533 | { |
| 534 | int ret = 0; |
| 535 | if (kbuf) { |
| 536 | const unsigned long *k = kbuf; |
| 537 | while (count >= sizeof(*k) && !ret) { |
| 538 | ret = putreg(target, pos, *k++); |
| 539 | count -= sizeof(*k); |
| 540 | pos += sizeof(*k); |
| 541 | } |
| 542 | } else { |
| 543 | const unsigned long __user *u = ubuf; |
| 544 | while (count >= sizeof(*u) && !ret) { |
| 545 | unsigned long word; |
| 546 | ret = __get_user(word, u++); |
| 547 | if (ret) |
| 548 | break; |
| 549 | ret = putreg(target, pos, word); |
| 550 | count -= sizeof(*u); |
| 551 | pos += sizeof(*u); |
| 552 | } |
| 553 | } |
| 554 | return ret; |
| 555 | } |
| 556 | |
| 557 | static void ptrace_triggered(struct perf_event *bp, |
| 558 | struct perf_sample_data *data, |
| 559 | struct pt_regs *regs) |
| 560 | { |
| 561 | int i; |
| 562 | struct thread_struct *thread = &(current->thread); |
| 563 | |
| 564 | /* |
| 565 | * Store in the virtual DR6 register the fact that the breakpoint |
| 566 | * was hit so the thread's debugger will see it. |
| 567 | */ |
| 568 | for (i = 0; i < HBP_NUM; i++) { |
| 569 | if (thread->ptrace_bps[i] == bp) |
| 570 | break; |
| 571 | } |
| 572 | |
| 573 | thread->debugreg6 |= (DR_TRAP0 << i); |
| 574 | } |
| 575 | |
| 576 | /* |
| 577 | * Walk through every ptrace breakpoints for this thread and |
| 578 | * build the dr7 value on top of their attributes. |
| 579 | * |
| 580 | */ |
| 581 | static unsigned long ptrace_get_dr7(struct perf_event *bp[]) |
| 582 | { |
| 583 | int i; |
| 584 | int dr7 = 0; |
| 585 | struct arch_hw_breakpoint *info; |
| 586 | |
| 587 | for (i = 0; i < HBP_NUM; i++) { |
| 588 | if (bp[i] && !bp[i]->attr.disabled) { |
| 589 | info = counter_arch_bp(bp[i]); |
| 590 | dr7 |= encode_dr7(i, info->len, info->type); |
| 591 | } |
| 592 | } |
| 593 | |
| 594 | return dr7; |
| 595 | } |
| 596 | |
| 597 | static int ptrace_fill_bp_fields(struct perf_event_attr *attr, |
| 598 | int len, int type, bool disabled) |
| 599 | { |
| 600 | int err, bp_len, bp_type; |
| 601 | |
| 602 | err = arch_bp_generic_fields(len, type, &bp_len, &bp_type); |
| 603 | if (!err) { |
| 604 | attr->bp_len = bp_len; |
| 605 | attr->bp_type = bp_type; |
| 606 | attr->disabled = disabled; |
| 607 | } |
| 608 | |
| 609 | return err; |
| 610 | } |
| 611 | |
| 612 | static struct perf_event * |
| 613 | ptrace_register_breakpoint(struct task_struct *tsk, int len, int type, |
| 614 | unsigned long addr, bool disabled) |
| 615 | { |
| 616 | struct perf_event_attr attr; |
| 617 | int err; |
| 618 | |
| 619 | ptrace_breakpoint_init(&attr); |
| 620 | attr.bp_addr = addr; |
| 621 | |
| 622 | err = ptrace_fill_bp_fields(&attr, len, type, disabled); |
| 623 | if (err) |
| 624 | return ERR_PTR(err); |
| 625 | |
| 626 | return register_user_hw_breakpoint(&attr, ptrace_triggered, |
| 627 | NULL, tsk); |
| 628 | } |
| 629 | |
| 630 | static int ptrace_modify_breakpoint(struct perf_event *bp, int len, int type, |
| 631 | int disabled) |
| 632 | { |
| 633 | struct perf_event_attr attr = bp->attr; |
| 634 | int err; |
| 635 | |
| 636 | err = ptrace_fill_bp_fields(&attr, len, type, disabled); |
| 637 | if (err) |
| 638 | return err; |
| 639 | |
| 640 | return modify_user_hw_breakpoint(bp, &attr); |
| 641 | } |
| 642 | |
| 643 | /* |
| 644 | * Handle ptrace writes to debug register 7. |
| 645 | */ |
| 646 | static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data) |
| 647 | { |
| 648 | struct thread_struct *thread = &tsk->thread; |
| 649 | unsigned long old_dr7; |
| 650 | bool second_pass = false; |
| 651 | int i, rc, ret = 0; |
| 652 | |
| 653 | data &= ~DR_CONTROL_RESERVED; |
| 654 | old_dr7 = ptrace_get_dr7(thread->ptrace_bps); |
| 655 | |
| 656 | restore: |
| 657 | rc = 0; |
| 658 | for (i = 0; i < HBP_NUM; i++) { |
| 659 | unsigned len, type; |
| 660 | bool disabled = !decode_dr7(data, i, &len, &type); |
| 661 | struct perf_event *bp = thread->ptrace_bps[i]; |
| 662 | |
| 663 | if (!bp) { |
| 664 | if (disabled) |
| 665 | continue; |
| 666 | |
| 667 | bp = ptrace_register_breakpoint(tsk, |
| 668 | len, type, 0, disabled); |
| 669 | if (IS_ERR(bp)) { |
| 670 | rc = PTR_ERR(bp); |
| 671 | break; |
| 672 | } |
| 673 | |
| 674 | thread->ptrace_bps[i] = bp; |
| 675 | continue; |
| 676 | } |
| 677 | |
| 678 | rc = ptrace_modify_breakpoint(bp, len, type, disabled); |
| 679 | if (rc) |
| 680 | break; |
| 681 | } |
| 682 | |
| 683 | /* Restore if the first pass failed, second_pass shouldn't fail. */ |
| 684 | if (rc && !WARN_ON(second_pass)) { |
| 685 | ret = rc; |
| 686 | data = old_dr7; |
| 687 | second_pass = true; |
| 688 | goto restore; |
| 689 | } |
| 690 | |
| 691 | return ret; |
| 692 | } |
| 693 | |
| 694 | /* |
| 695 | * Handle PTRACE_PEEKUSR calls for the debug register area. |
| 696 | */ |
| 697 | static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n) |
| 698 | { |
| 699 | struct thread_struct *thread = &tsk->thread; |
| 700 | unsigned long val = 0; |
| 701 | |
| 702 | if (n < HBP_NUM) { |
| 703 | struct perf_event *bp = thread->ptrace_bps[n]; |
| 704 | |
| 705 | if (bp) |
| 706 | val = bp->hw.info.address; |
| 707 | } else if (n == 6) { |
| 708 | val = thread->debugreg6; |
| 709 | } else if (n == 7) { |
| 710 | val = thread->ptrace_dr7; |
| 711 | } |
| 712 | return val; |
| 713 | } |
| 714 | |
| 715 | static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr, |
| 716 | unsigned long addr) |
| 717 | { |
| 718 | struct thread_struct *t = &tsk->thread; |
| 719 | struct perf_event *bp = t->ptrace_bps[nr]; |
| 720 | int err = 0; |
| 721 | |
| 722 | if (!bp) { |
| 723 | /* |
| 724 | * Put stub len and type to create an inactive but correct bp. |
| 725 | * |
| 726 | * CHECKME: the previous code returned -EIO if the addr wasn't |
| 727 | * a valid task virtual addr. The new one will return -EINVAL in |
| 728 | * this case. |
| 729 | * -EINVAL may be what we want for in-kernel breakpoints users, |
| 730 | * but -EIO looks better for ptrace, since we refuse a register |
| 731 | * writing for the user. And anyway this is the previous |
| 732 | * behaviour. |
| 733 | */ |
| 734 | bp = ptrace_register_breakpoint(tsk, |
| 735 | X86_BREAKPOINT_LEN_1, X86_BREAKPOINT_WRITE, |
| 736 | addr, true); |
| 737 | if (IS_ERR(bp)) |
| 738 | err = PTR_ERR(bp); |
| 739 | else |
| 740 | t->ptrace_bps[nr] = bp; |
| 741 | } else { |
| 742 | struct perf_event_attr attr = bp->attr; |
| 743 | |
| 744 | attr.bp_addr = addr; |
| 745 | err = modify_user_hw_breakpoint(bp, &attr); |
| 746 | } |
| 747 | |
| 748 | return err; |
| 749 | } |
| 750 | |
| 751 | /* |
| 752 | * Handle PTRACE_POKEUSR calls for the debug register area. |
| 753 | */ |
| 754 | static int ptrace_set_debugreg(struct task_struct *tsk, int n, |
| 755 | unsigned long val) |
| 756 | { |
| 757 | struct thread_struct *thread = &tsk->thread; |
| 758 | /* There are no DR4 or DR5 registers */ |
| 759 | int rc = -EIO; |
| 760 | |
| 761 | if (n < HBP_NUM) { |
| 762 | rc = ptrace_set_breakpoint_addr(tsk, n, val); |
| 763 | } else if (n == 6) { |
| 764 | thread->debugreg6 = val; |
| 765 | rc = 0; |
| 766 | } else if (n == 7) { |
| 767 | rc = ptrace_write_dr7(tsk, val); |
| 768 | if (!rc) |
| 769 | thread->ptrace_dr7 = val; |
| 770 | } |
| 771 | return rc; |
| 772 | } |
| 773 | |
| 774 | /* |
| 775 | * These access the current or another (stopped) task's io permission |
| 776 | * bitmap for debugging or core dump. |
| 777 | */ |
| 778 | static int ioperm_active(struct task_struct *target, |
| 779 | const struct user_regset *regset) |
| 780 | { |
| 781 | return target->thread.io_bitmap_max / regset->size; |
| 782 | } |
| 783 | |
| 784 | static int ioperm_get(struct task_struct *target, |
| 785 | const struct user_regset *regset, |
| 786 | unsigned int pos, unsigned int count, |
| 787 | void *kbuf, void __user *ubuf) |
| 788 | { |
| 789 | if (!target->thread.io_bitmap_ptr) |
| 790 | return -ENXIO; |
| 791 | |
| 792 | return user_regset_copyout(&pos, &count, &kbuf, &ubuf, |
| 793 | target->thread.io_bitmap_ptr, |
| 794 | 0, IO_BITMAP_BYTES); |
| 795 | } |
| 796 | |
| 797 | /* |
| 798 | * Called by kernel/ptrace.c when detaching.. |
| 799 | * |
| 800 | * Make sure the single step bit is not set. |
| 801 | */ |
| 802 | void ptrace_disable(struct task_struct *child) |
| 803 | { |
| 804 | user_disable_single_step(child); |
| 805 | #ifdef TIF_SYSCALL_EMU |
| 806 | clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); |
| 807 | #endif |
| 808 | } |
| 809 | |
| 810 | #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION |
| 811 | static const struct user_regset_view user_x86_32_view; /* Initialized below. */ |
| 812 | #endif |
| 813 | |
| 814 | long arch_ptrace(struct task_struct *child, long request, |
| 815 | unsigned long addr, unsigned long data) |
| 816 | { |
| 817 | int ret; |
| 818 | unsigned long __user *datap = (unsigned long __user *)data; |
| 819 | |
| 820 | switch (request) { |
| 821 | /* read the word at location addr in the USER area. */ |
| 822 | case PTRACE_PEEKUSR: { |
| 823 | unsigned long tmp; |
| 824 | |
| 825 | ret = -EIO; |
| 826 | if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user)) |
| 827 | break; |
| 828 | |
| 829 | tmp = 0; /* Default return condition */ |
| 830 | if (addr < sizeof(struct user_regs_struct)) |
| 831 | tmp = getreg(child, addr); |
| 832 | else if (addr >= offsetof(struct user, u_debugreg[0]) && |
| 833 | addr <= offsetof(struct user, u_debugreg[7])) { |
| 834 | addr -= offsetof(struct user, u_debugreg[0]); |
| 835 | tmp = ptrace_get_debugreg(child, addr / sizeof(data)); |
| 836 | } |
| 837 | ret = put_user(tmp, datap); |
| 838 | break; |
| 839 | } |
| 840 | |
| 841 | case PTRACE_POKEUSR: /* write the word at location addr in the USER area */ |
| 842 | ret = -EIO; |
| 843 | if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user)) |
| 844 | break; |
| 845 | |
| 846 | if (addr < sizeof(struct user_regs_struct)) |
| 847 | ret = putreg(child, addr, data); |
| 848 | else if (addr >= offsetof(struct user, u_debugreg[0]) && |
| 849 | addr <= offsetof(struct user, u_debugreg[7])) { |
| 850 | addr -= offsetof(struct user, u_debugreg[0]); |
| 851 | ret = ptrace_set_debugreg(child, |
| 852 | addr / sizeof(data), data); |
| 853 | } |
| 854 | break; |
| 855 | |
| 856 | case PTRACE_GETREGS: /* Get all gp regs from the child. */ |
| 857 | return copy_regset_to_user(child, |
| 858 | task_user_regset_view(current), |
| 859 | REGSET_GENERAL, |
| 860 | 0, sizeof(struct user_regs_struct), |
| 861 | datap); |
| 862 | |
| 863 | case PTRACE_SETREGS: /* Set all gp regs in the child. */ |
| 864 | return copy_regset_from_user(child, |
| 865 | task_user_regset_view(current), |
| 866 | REGSET_GENERAL, |
| 867 | 0, sizeof(struct user_regs_struct), |
| 868 | datap); |
| 869 | |
| 870 | case PTRACE_GETFPREGS: /* Get the child FPU state. */ |
| 871 | return copy_regset_to_user(child, |
| 872 | task_user_regset_view(current), |
| 873 | REGSET_FP, |
| 874 | 0, sizeof(struct user_i387_struct), |
| 875 | datap); |
| 876 | |
| 877 | case PTRACE_SETFPREGS: /* Set the child FPU state. */ |
| 878 | return copy_regset_from_user(child, |
| 879 | task_user_regset_view(current), |
| 880 | REGSET_FP, |
| 881 | 0, sizeof(struct user_i387_struct), |
| 882 | datap); |
| 883 | |
| 884 | #ifdef CONFIG_X86_32 |
| 885 | case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */ |
| 886 | return copy_regset_to_user(child, &user_x86_32_view, |
| 887 | REGSET_XFP, |
| 888 | 0, sizeof(struct user_fxsr_struct), |
| 889 | datap) ? -EIO : 0; |
| 890 | |
| 891 | case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */ |
| 892 | return copy_regset_from_user(child, &user_x86_32_view, |
| 893 | REGSET_XFP, |
| 894 | 0, sizeof(struct user_fxsr_struct), |
| 895 | datap) ? -EIO : 0; |
| 896 | #endif |
| 897 | |
| 898 | #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION |
| 899 | case PTRACE_GET_THREAD_AREA: |
| 900 | if ((int) addr < 0) |
| 901 | return -EIO; |
| 902 | ret = do_get_thread_area(child, addr, |
| 903 | (struct user_desc __user *)data); |
| 904 | break; |
| 905 | |
| 906 | case PTRACE_SET_THREAD_AREA: |
| 907 | if ((int) addr < 0) |
| 908 | return -EIO; |
| 909 | ret = do_set_thread_area(child, addr, |
| 910 | (struct user_desc __user *)data, 0); |
| 911 | break; |
| 912 | #endif |
| 913 | |
| 914 | #ifdef CONFIG_X86_64 |
| 915 | /* normal 64bit interface to access TLS data. |
| 916 | Works just like arch_prctl, except that the arguments |
| 917 | are reversed. */ |
| 918 | case PTRACE_ARCH_PRCTL: |
| 919 | ret = do_arch_prctl(child, data, addr); |
| 920 | break; |
| 921 | #endif |
| 922 | |
| 923 | default: |
| 924 | ret = ptrace_request(child, request, addr, data); |
| 925 | break; |
| 926 | } |
| 927 | |
| 928 | return ret; |
| 929 | } |
| 930 | |
| 931 | #ifdef CONFIG_IA32_EMULATION |
| 932 | |
| 933 | #include <linux/compat.h> |
| 934 | #include <linux/syscalls.h> |
| 935 | #include <asm/ia32.h> |
| 936 | #include <asm/user32.h> |
| 937 | |
| 938 | #define R32(l,q) \ |
| 939 | case offsetof(struct user32, regs.l): \ |
| 940 | regs->q = value; break |
| 941 | |
| 942 | #define SEG32(rs) \ |
| 943 | case offsetof(struct user32, regs.rs): \ |
| 944 | return set_segment_reg(child, \ |
| 945 | offsetof(struct user_regs_struct, rs), \ |
| 946 | value); \ |
| 947 | break |
| 948 | |
| 949 | static int putreg32(struct task_struct *child, unsigned regno, u32 value) |
| 950 | { |
| 951 | struct pt_regs *regs = task_pt_regs(child); |
| 952 | |
| 953 | switch (regno) { |
| 954 | |
| 955 | SEG32(cs); |
| 956 | SEG32(ds); |
| 957 | SEG32(es); |
| 958 | SEG32(fs); |
| 959 | SEG32(gs); |
| 960 | SEG32(ss); |
| 961 | |
| 962 | R32(ebx, bx); |
| 963 | R32(ecx, cx); |
| 964 | R32(edx, dx); |
| 965 | R32(edi, di); |
| 966 | R32(esi, si); |
| 967 | R32(ebp, bp); |
| 968 | R32(eax, ax); |
| 969 | R32(eip, ip); |
| 970 | R32(esp, sp); |
| 971 | |
| 972 | case offsetof(struct user32, regs.orig_eax): |
| 973 | /* |
| 974 | * A 32-bit debugger setting orig_eax means to restore |
| 975 | * the state of the task restarting a 32-bit syscall. |
| 976 | * Make sure we interpret the -ERESTART* codes correctly |
| 977 | * in case the task is not actually still sitting at the |
| 978 | * exit from a 32-bit syscall with TS_COMPAT still set. |
| 979 | */ |
| 980 | regs->orig_ax = value; |
| 981 | if (syscall_get_nr(child, regs) >= 0) |
| 982 | task_thread_info(child)->status |= TS_COMPAT; |
| 983 | break; |
| 984 | |
| 985 | case offsetof(struct user32, regs.eflags): |
| 986 | return set_flags(child, value); |
| 987 | |
| 988 | case offsetof(struct user32, u_debugreg[0]) ... |
| 989 | offsetof(struct user32, u_debugreg[7]): |
| 990 | regno -= offsetof(struct user32, u_debugreg[0]); |
| 991 | return ptrace_set_debugreg(child, regno / 4, value); |
| 992 | |
| 993 | default: |
| 994 | if (regno > sizeof(struct user32) || (regno & 3)) |
| 995 | return -EIO; |
| 996 | |
| 997 | /* |
| 998 | * Other dummy fields in the virtual user structure |
| 999 | * are ignored |
| 1000 | */ |
| 1001 | break; |
| 1002 | } |
| 1003 | return 0; |
| 1004 | } |
| 1005 | |
| 1006 | #undef R32 |
| 1007 | #undef SEG32 |
| 1008 | |
| 1009 | #define R32(l,q) \ |
| 1010 | case offsetof(struct user32, regs.l): \ |
| 1011 | *val = regs->q; break |
| 1012 | |
| 1013 | #define SEG32(rs) \ |
| 1014 | case offsetof(struct user32, regs.rs): \ |
| 1015 | *val = get_segment_reg(child, \ |
| 1016 | offsetof(struct user_regs_struct, rs)); \ |
| 1017 | break |
| 1018 | |
| 1019 | static int getreg32(struct task_struct *child, unsigned regno, u32 *val) |
| 1020 | { |
| 1021 | struct pt_regs *regs = task_pt_regs(child); |
| 1022 | |
| 1023 | switch (regno) { |
| 1024 | |
| 1025 | SEG32(ds); |
| 1026 | SEG32(es); |
| 1027 | SEG32(fs); |
| 1028 | SEG32(gs); |
| 1029 | |
| 1030 | R32(cs, cs); |
| 1031 | R32(ss, ss); |
| 1032 | R32(ebx, bx); |
| 1033 | R32(ecx, cx); |
| 1034 | R32(edx, dx); |
| 1035 | R32(edi, di); |
| 1036 | R32(esi, si); |
| 1037 | R32(ebp, bp); |
| 1038 | R32(eax, ax); |
| 1039 | R32(orig_eax, orig_ax); |
| 1040 | R32(eip, ip); |
| 1041 | R32(esp, sp); |
| 1042 | |
| 1043 | case offsetof(struct user32, regs.eflags): |
| 1044 | *val = get_flags(child); |
| 1045 | break; |
| 1046 | |
| 1047 | case offsetof(struct user32, u_debugreg[0]) ... |
| 1048 | offsetof(struct user32, u_debugreg[7]): |
| 1049 | regno -= offsetof(struct user32, u_debugreg[0]); |
| 1050 | *val = ptrace_get_debugreg(child, regno / 4); |
| 1051 | break; |
| 1052 | |
| 1053 | default: |
| 1054 | if (regno > sizeof(struct user32) || (regno & 3)) |
| 1055 | return -EIO; |
| 1056 | |
| 1057 | /* |
| 1058 | * Other dummy fields in the virtual user structure |
| 1059 | * are ignored |
| 1060 | */ |
| 1061 | *val = 0; |
| 1062 | break; |
| 1063 | } |
| 1064 | return 0; |
| 1065 | } |
| 1066 | |
| 1067 | #undef R32 |
| 1068 | #undef SEG32 |
| 1069 | |
| 1070 | static int genregs32_get(struct task_struct *target, |
| 1071 | const struct user_regset *regset, |
| 1072 | unsigned int pos, unsigned int count, |
| 1073 | void *kbuf, void __user *ubuf) |
| 1074 | { |
| 1075 | if (kbuf) { |
| 1076 | compat_ulong_t *k = kbuf; |
| 1077 | while (count >= sizeof(*k)) { |
| 1078 | getreg32(target, pos, k++); |
| 1079 | count -= sizeof(*k); |
| 1080 | pos += sizeof(*k); |
| 1081 | } |
| 1082 | } else { |
| 1083 | compat_ulong_t __user *u = ubuf; |
| 1084 | while (count >= sizeof(*u)) { |
| 1085 | compat_ulong_t word; |
| 1086 | getreg32(target, pos, &word); |
| 1087 | if (__put_user(word, u++)) |
| 1088 | return -EFAULT; |
| 1089 | count -= sizeof(*u); |
| 1090 | pos += sizeof(*u); |
| 1091 | } |
| 1092 | } |
| 1093 | |
| 1094 | return 0; |
| 1095 | } |
| 1096 | |
| 1097 | static int genregs32_set(struct task_struct *target, |
| 1098 | const struct user_regset *regset, |
| 1099 | unsigned int pos, unsigned int count, |
| 1100 | const void *kbuf, const void __user *ubuf) |
| 1101 | { |
| 1102 | int ret = 0; |
| 1103 | if (kbuf) { |
| 1104 | const compat_ulong_t *k = kbuf; |
| 1105 | while (count >= sizeof(*k) && !ret) { |
| 1106 | ret = putreg32(target, pos, *k++); |
| 1107 | count -= sizeof(*k); |
| 1108 | pos += sizeof(*k); |
| 1109 | } |
| 1110 | } else { |
| 1111 | const compat_ulong_t __user *u = ubuf; |
| 1112 | while (count >= sizeof(*u) && !ret) { |
| 1113 | compat_ulong_t word; |
| 1114 | ret = __get_user(word, u++); |
| 1115 | if (ret) |
| 1116 | break; |
| 1117 | ret = putreg32(target, pos, word); |
| 1118 | count -= sizeof(*u); |
| 1119 | pos += sizeof(*u); |
| 1120 | } |
| 1121 | } |
| 1122 | return ret; |
| 1123 | } |
| 1124 | |
| 1125 | #ifdef CONFIG_X86_X32_ABI |
| 1126 | static long x32_arch_ptrace(struct task_struct *child, |
| 1127 | compat_long_t request, compat_ulong_t caddr, |
| 1128 | compat_ulong_t cdata) |
| 1129 | { |
| 1130 | unsigned long addr = caddr; |
| 1131 | unsigned long data = cdata; |
| 1132 | void __user *datap = compat_ptr(data); |
| 1133 | int ret; |
| 1134 | |
| 1135 | switch (request) { |
| 1136 | /* Read 32bits at location addr in the USER area. Only allow |
| 1137 | to return the lower 32bits of segment and debug registers. */ |
| 1138 | case PTRACE_PEEKUSR: { |
| 1139 | u32 tmp; |
| 1140 | |
| 1141 | ret = -EIO; |
| 1142 | if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) || |
| 1143 | addr < offsetof(struct user_regs_struct, cs)) |
| 1144 | break; |
| 1145 | |
| 1146 | tmp = 0; /* Default return condition */ |
| 1147 | if (addr < sizeof(struct user_regs_struct)) |
| 1148 | tmp = getreg(child, addr); |
| 1149 | else if (addr >= offsetof(struct user, u_debugreg[0]) && |
| 1150 | addr <= offsetof(struct user, u_debugreg[7])) { |
| 1151 | addr -= offsetof(struct user, u_debugreg[0]); |
| 1152 | tmp = ptrace_get_debugreg(child, addr / sizeof(data)); |
| 1153 | } |
| 1154 | ret = put_user(tmp, (__u32 __user *)datap); |
| 1155 | break; |
| 1156 | } |
| 1157 | |
| 1158 | /* Write the word at location addr in the USER area. Only allow |
| 1159 | to update segment and debug registers with the upper 32bits |
| 1160 | zero-extended. */ |
| 1161 | case PTRACE_POKEUSR: |
| 1162 | ret = -EIO; |
| 1163 | if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) || |
| 1164 | addr < offsetof(struct user_regs_struct, cs)) |
| 1165 | break; |
| 1166 | |
| 1167 | if (addr < sizeof(struct user_regs_struct)) |
| 1168 | ret = putreg(child, addr, data); |
| 1169 | else if (addr >= offsetof(struct user, u_debugreg[0]) && |
| 1170 | addr <= offsetof(struct user, u_debugreg[7])) { |
| 1171 | addr -= offsetof(struct user, u_debugreg[0]); |
| 1172 | ret = ptrace_set_debugreg(child, |
| 1173 | addr / sizeof(data), data); |
| 1174 | } |
| 1175 | break; |
| 1176 | |
| 1177 | case PTRACE_GETREGS: /* Get all gp regs from the child. */ |
| 1178 | return copy_regset_to_user(child, |
| 1179 | task_user_regset_view(current), |
| 1180 | REGSET_GENERAL, |
| 1181 | 0, sizeof(struct user_regs_struct), |
| 1182 | datap); |
| 1183 | |
| 1184 | case PTRACE_SETREGS: /* Set all gp regs in the child. */ |
| 1185 | return copy_regset_from_user(child, |
| 1186 | task_user_regset_view(current), |
| 1187 | REGSET_GENERAL, |
| 1188 | 0, sizeof(struct user_regs_struct), |
| 1189 | datap); |
| 1190 | |
| 1191 | case PTRACE_GETFPREGS: /* Get the child FPU state. */ |
| 1192 | return copy_regset_to_user(child, |
| 1193 | task_user_regset_view(current), |
| 1194 | REGSET_FP, |
| 1195 | 0, sizeof(struct user_i387_struct), |
| 1196 | datap); |
| 1197 | |
| 1198 | case PTRACE_SETFPREGS: /* Set the child FPU state. */ |
| 1199 | return copy_regset_from_user(child, |
| 1200 | task_user_regset_view(current), |
| 1201 | REGSET_FP, |
| 1202 | 0, sizeof(struct user_i387_struct), |
| 1203 | datap); |
| 1204 | |
| 1205 | default: |
| 1206 | return compat_ptrace_request(child, request, addr, data); |
| 1207 | } |
| 1208 | |
| 1209 | return ret; |
| 1210 | } |
| 1211 | #endif |
| 1212 | |
| 1213 | long compat_arch_ptrace(struct task_struct *child, compat_long_t request, |
| 1214 | compat_ulong_t caddr, compat_ulong_t cdata) |
| 1215 | { |
| 1216 | unsigned long addr = caddr; |
| 1217 | unsigned long data = cdata; |
| 1218 | void __user *datap = compat_ptr(data); |
| 1219 | int ret; |
| 1220 | __u32 val; |
| 1221 | |
| 1222 | #ifdef CONFIG_X86_X32_ABI |
| 1223 | if (!is_ia32_task()) |
| 1224 | return x32_arch_ptrace(child, request, caddr, cdata); |
| 1225 | #endif |
| 1226 | |
| 1227 | switch (request) { |
| 1228 | case PTRACE_PEEKUSR: |
| 1229 | ret = getreg32(child, addr, &val); |
| 1230 | if (ret == 0) |
| 1231 | ret = put_user(val, (__u32 __user *)datap); |
| 1232 | break; |
| 1233 | |
| 1234 | case PTRACE_POKEUSR: |
| 1235 | ret = putreg32(child, addr, data); |
| 1236 | break; |
| 1237 | |
| 1238 | case PTRACE_GETREGS: /* Get all gp regs from the child. */ |
| 1239 | return copy_regset_to_user(child, &user_x86_32_view, |
| 1240 | REGSET_GENERAL, |
| 1241 | 0, sizeof(struct user_regs_struct32), |
| 1242 | datap); |
| 1243 | |
| 1244 | case PTRACE_SETREGS: /* Set all gp regs in the child. */ |
| 1245 | return copy_regset_from_user(child, &user_x86_32_view, |
| 1246 | REGSET_GENERAL, 0, |
| 1247 | sizeof(struct user_regs_struct32), |
| 1248 | datap); |
| 1249 | |
| 1250 | case PTRACE_GETFPREGS: /* Get the child FPU state. */ |
| 1251 | return copy_regset_to_user(child, &user_x86_32_view, |
| 1252 | REGSET_FP, 0, |
| 1253 | sizeof(struct user_i387_ia32_struct), |
| 1254 | datap); |
| 1255 | |
| 1256 | case PTRACE_SETFPREGS: /* Set the child FPU state. */ |
| 1257 | return copy_regset_from_user( |
| 1258 | child, &user_x86_32_view, REGSET_FP, |
| 1259 | 0, sizeof(struct user_i387_ia32_struct), datap); |
| 1260 | |
| 1261 | case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */ |
| 1262 | return copy_regset_to_user(child, &user_x86_32_view, |
| 1263 | REGSET_XFP, 0, |
| 1264 | sizeof(struct user32_fxsr_struct), |
| 1265 | datap); |
| 1266 | |
| 1267 | case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */ |
| 1268 | return copy_regset_from_user(child, &user_x86_32_view, |
| 1269 | REGSET_XFP, 0, |
| 1270 | sizeof(struct user32_fxsr_struct), |
| 1271 | datap); |
| 1272 | |
| 1273 | case PTRACE_GET_THREAD_AREA: |
| 1274 | case PTRACE_SET_THREAD_AREA: |
| 1275 | return arch_ptrace(child, request, addr, data); |
| 1276 | |
| 1277 | default: |
| 1278 | return compat_ptrace_request(child, request, addr, data); |
| 1279 | } |
| 1280 | |
| 1281 | return ret; |
| 1282 | } |
| 1283 | |
| 1284 | #endif /* CONFIG_IA32_EMULATION */ |
| 1285 | |
| 1286 | #ifdef CONFIG_X86_64 |
| 1287 | |
| 1288 | static struct user_regset x86_64_regsets[] __read_mostly = { |
| 1289 | [REGSET_GENERAL] = { |
| 1290 | .core_note_type = NT_PRSTATUS, |
| 1291 | .n = sizeof(struct user_regs_struct) / sizeof(long), |
| 1292 | .size = sizeof(long), .align = sizeof(long), |
| 1293 | .get = genregs_get, .set = genregs_set |
| 1294 | }, |
| 1295 | [REGSET_FP] = { |
| 1296 | .core_note_type = NT_PRFPREG, |
| 1297 | .n = sizeof(struct user_i387_struct) / sizeof(long), |
| 1298 | .size = sizeof(long), .align = sizeof(long), |
| 1299 | .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set |
| 1300 | }, |
| 1301 | [REGSET_XSTATE] = { |
| 1302 | .core_note_type = NT_X86_XSTATE, |
| 1303 | .size = sizeof(u64), .align = sizeof(u64), |
| 1304 | .active = xstateregs_active, .get = xstateregs_get, |
| 1305 | .set = xstateregs_set |
| 1306 | }, |
| 1307 | [REGSET_IOPERM64] = { |
| 1308 | .core_note_type = NT_386_IOPERM, |
| 1309 | .n = IO_BITMAP_LONGS, |
| 1310 | .size = sizeof(long), .align = sizeof(long), |
| 1311 | .active = ioperm_active, .get = ioperm_get |
| 1312 | }, |
| 1313 | }; |
| 1314 | |
| 1315 | static const struct user_regset_view user_x86_64_view = { |
| 1316 | .name = "x86_64", .e_machine = EM_X86_64, |
| 1317 | .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets) |
| 1318 | }; |
| 1319 | |
| 1320 | #else /* CONFIG_X86_32 */ |
| 1321 | |
| 1322 | #define user_regs_struct32 user_regs_struct |
| 1323 | #define genregs32_get genregs_get |
| 1324 | #define genregs32_set genregs_set |
| 1325 | |
| 1326 | #endif /* CONFIG_X86_64 */ |
| 1327 | |
| 1328 | #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION |
| 1329 | static struct user_regset x86_32_regsets[] __read_mostly = { |
| 1330 | [REGSET_GENERAL] = { |
| 1331 | .core_note_type = NT_PRSTATUS, |
| 1332 | .n = sizeof(struct user_regs_struct32) / sizeof(u32), |
| 1333 | .size = sizeof(u32), .align = sizeof(u32), |
| 1334 | .get = genregs32_get, .set = genregs32_set |
| 1335 | }, |
| 1336 | [REGSET_FP] = { |
| 1337 | .core_note_type = NT_PRFPREG, |
| 1338 | .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32), |
| 1339 | .size = sizeof(u32), .align = sizeof(u32), |
| 1340 | .active = fpregs_active, .get = fpregs_get, .set = fpregs_set |
| 1341 | }, |
| 1342 | [REGSET_XFP] = { |
| 1343 | .core_note_type = NT_PRXFPREG, |
| 1344 | .n = sizeof(struct user32_fxsr_struct) / sizeof(u32), |
| 1345 | .size = sizeof(u32), .align = sizeof(u32), |
| 1346 | .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set |
| 1347 | }, |
| 1348 | [REGSET_XSTATE] = { |
| 1349 | .core_note_type = NT_X86_XSTATE, |
| 1350 | .size = sizeof(u64), .align = sizeof(u64), |
| 1351 | .active = xstateregs_active, .get = xstateregs_get, |
| 1352 | .set = xstateregs_set |
| 1353 | }, |
| 1354 | [REGSET_TLS] = { |
| 1355 | .core_note_type = NT_386_TLS, |
| 1356 | .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN, |
| 1357 | .size = sizeof(struct user_desc), |
| 1358 | .align = sizeof(struct user_desc), |
| 1359 | .active = regset_tls_active, |
| 1360 | .get = regset_tls_get, .set = regset_tls_set |
| 1361 | }, |
| 1362 | [REGSET_IOPERM32] = { |
| 1363 | .core_note_type = NT_386_IOPERM, |
| 1364 | .n = IO_BITMAP_BYTES / sizeof(u32), |
| 1365 | .size = sizeof(u32), .align = sizeof(u32), |
| 1366 | .active = ioperm_active, .get = ioperm_get |
| 1367 | }, |
| 1368 | }; |
| 1369 | |
| 1370 | static const struct user_regset_view user_x86_32_view = { |
| 1371 | .name = "i386", .e_machine = EM_386, |
| 1372 | .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets) |
| 1373 | }; |
| 1374 | #endif |
| 1375 | |
| 1376 | /* |
| 1377 | * This represents bytes 464..511 in the memory layout exported through |
| 1378 | * the REGSET_XSTATE interface. |
| 1379 | */ |
| 1380 | u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS]; |
| 1381 | |
| 1382 | void update_regset_xstate_info(unsigned int size, u64 xstate_mask) |
| 1383 | { |
| 1384 | #ifdef CONFIG_X86_64 |
| 1385 | x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64); |
| 1386 | #endif |
| 1387 | #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION |
| 1388 | x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64); |
| 1389 | #endif |
| 1390 | xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask; |
| 1391 | } |
| 1392 | |
| 1393 | const struct user_regset_view *task_user_regset_view(struct task_struct *task) |
| 1394 | { |
| 1395 | #ifdef CONFIG_IA32_EMULATION |
| 1396 | if (test_tsk_thread_flag(task, TIF_IA32)) |
| 1397 | #endif |
| 1398 | #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION |
| 1399 | return &user_x86_32_view; |
| 1400 | #endif |
| 1401 | #ifdef CONFIG_X86_64 |
| 1402 | return &user_x86_64_view; |
| 1403 | #endif |
| 1404 | } |
| 1405 | |
| 1406 | static void fill_sigtrap_info(struct task_struct *tsk, |
| 1407 | struct pt_regs *regs, |
| 1408 | int error_code, int si_code, |
| 1409 | struct siginfo *info) |
| 1410 | { |
| 1411 | tsk->thread.trap_nr = X86_TRAP_DB; |
| 1412 | tsk->thread.error_code = error_code; |
| 1413 | |
| 1414 | memset(info, 0, sizeof(*info)); |
| 1415 | info->si_signo = SIGTRAP; |
| 1416 | info->si_code = si_code; |
| 1417 | info->si_addr = user_mode(regs) ? (void __user *)regs->ip : NULL; |
| 1418 | } |
| 1419 | |
| 1420 | void user_single_step_siginfo(struct task_struct *tsk, |
| 1421 | struct pt_regs *regs, |
| 1422 | struct siginfo *info) |
| 1423 | { |
| 1424 | fill_sigtrap_info(tsk, regs, 0, TRAP_BRKPT, info); |
| 1425 | } |
| 1426 | |
| 1427 | void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, |
| 1428 | int error_code, int si_code) |
| 1429 | { |
| 1430 | struct siginfo info; |
| 1431 | |
| 1432 | fill_sigtrap_info(tsk, regs, error_code, si_code, &info); |
| 1433 | /* Send us the fake SIGTRAP */ |
| 1434 | force_sig_info(SIGTRAP, &info, tsk); |
| 1435 | } |
| 1436 | |
| 1437 | static void do_audit_syscall_entry(struct pt_regs *regs, u32 arch) |
| 1438 | { |
| 1439 | #ifdef CONFIG_X86_64 |
| 1440 | if (arch == AUDIT_ARCH_X86_64) { |
| 1441 | audit_syscall_entry(regs->orig_ax, regs->di, |
| 1442 | regs->si, regs->dx, regs->r10); |
| 1443 | } else |
| 1444 | #endif |
| 1445 | { |
| 1446 | audit_syscall_entry(regs->orig_ax, regs->bx, |
| 1447 | regs->cx, regs->dx, regs->si); |
| 1448 | } |
| 1449 | } |
| 1450 | |
| 1451 | /* |
| 1452 | * We can return 0 to resume the syscall or anything else to go to phase |
| 1453 | * 2. If we resume the syscall, we need to put something appropriate in |
| 1454 | * regs->orig_ax. |
| 1455 | * |
| 1456 | * NB: We don't have full pt_regs here, but regs->orig_ax and regs->ax |
| 1457 | * are fully functional. |
| 1458 | * |
| 1459 | * For phase 2's benefit, our return value is: |
| 1460 | * 0: resume the syscall |
| 1461 | * 1: go to phase 2; no seccomp phase 2 needed |
| 1462 | * anything else: go to phase 2; pass return value to seccomp |
| 1463 | */ |
| 1464 | unsigned long syscall_trace_enter_phase1(struct pt_regs *regs, u32 arch) |
| 1465 | { |
| 1466 | unsigned long ret = 0; |
| 1467 | u32 work; |
| 1468 | |
| 1469 | BUG_ON(regs != task_pt_regs(current)); |
| 1470 | |
| 1471 | work = ACCESS_ONCE(current_thread_info()->flags) & |
| 1472 | _TIF_WORK_SYSCALL_ENTRY; |
| 1473 | |
| 1474 | /* |
| 1475 | * If TIF_NOHZ is set, we are required to call user_exit() before |
| 1476 | * doing anything that could touch RCU. |
| 1477 | */ |
| 1478 | if (work & _TIF_NOHZ) { |
| 1479 | user_exit(); |
| 1480 | work &= ~_TIF_NOHZ; |
| 1481 | } |
| 1482 | |
| 1483 | #ifdef CONFIG_SECCOMP |
| 1484 | /* |
| 1485 | * Do seccomp first -- it should minimize exposure of other |
| 1486 | * code, and keeping seccomp fast is probably more valuable |
| 1487 | * than the rest of this. |
| 1488 | */ |
| 1489 | if (work & _TIF_SECCOMP) { |
| 1490 | struct seccomp_data sd; |
| 1491 | |
| 1492 | sd.arch = arch; |
| 1493 | sd.nr = regs->orig_ax; |
| 1494 | sd.instruction_pointer = regs->ip; |
| 1495 | #ifdef CONFIG_X86_64 |
| 1496 | if (arch == AUDIT_ARCH_X86_64) { |
| 1497 | sd.args[0] = regs->di; |
| 1498 | sd.args[1] = regs->si; |
| 1499 | sd.args[2] = regs->dx; |
| 1500 | sd.args[3] = regs->r10; |
| 1501 | sd.args[4] = regs->r8; |
| 1502 | sd.args[5] = regs->r9; |
| 1503 | } else |
| 1504 | #endif |
| 1505 | { |
| 1506 | sd.args[0] = regs->bx; |
| 1507 | sd.args[1] = regs->cx; |
| 1508 | sd.args[2] = regs->dx; |
| 1509 | sd.args[3] = regs->si; |
| 1510 | sd.args[4] = regs->di; |
| 1511 | sd.args[5] = regs->bp; |
| 1512 | } |
| 1513 | |
| 1514 | BUILD_BUG_ON(SECCOMP_PHASE1_OK != 0); |
| 1515 | BUILD_BUG_ON(SECCOMP_PHASE1_SKIP != 1); |
| 1516 | |
| 1517 | ret = seccomp_phase1(&sd); |
| 1518 | if (ret == SECCOMP_PHASE1_SKIP) { |
| 1519 | regs->orig_ax = -1; |
| 1520 | ret = 0; |
| 1521 | } else if (ret != SECCOMP_PHASE1_OK) { |
| 1522 | return ret; /* Go directly to phase 2 */ |
| 1523 | } |
| 1524 | |
| 1525 | work &= ~_TIF_SECCOMP; |
| 1526 | } |
| 1527 | #endif |
| 1528 | |
| 1529 | /* Do our best to finish without phase 2. */ |
| 1530 | if (work == 0) |
| 1531 | return ret; /* seccomp and/or nohz only (ret == 0 here) */ |
| 1532 | |
| 1533 | #ifdef CONFIG_AUDITSYSCALL |
| 1534 | if (work == _TIF_SYSCALL_AUDIT) { |
| 1535 | /* |
| 1536 | * If there is no more work to be done except auditing, |
| 1537 | * then audit in phase 1. Phase 2 always audits, so, if |
| 1538 | * we audit here, then we can't go on to phase 2. |
| 1539 | */ |
| 1540 | do_audit_syscall_entry(regs, arch); |
| 1541 | return 0; |
| 1542 | } |
| 1543 | #endif |
| 1544 | |
| 1545 | return 1; /* Something is enabled that we can't handle in phase 1 */ |
| 1546 | } |
| 1547 | |
| 1548 | /* Returns the syscall nr to run (which should match regs->orig_ax). */ |
| 1549 | long syscall_trace_enter_phase2(struct pt_regs *regs, u32 arch, |
| 1550 | unsigned long phase1_result) |
| 1551 | { |
| 1552 | long ret = 0; |
| 1553 | u32 work = ACCESS_ONCE(current_thread_info()->flags) & |
| 1554 | _TIF_WORK_SYSCALL_ENTRY; |
| 1555 | |
| 1556 | BUG_ON(regs != task_pt_regs(current)); |
| 1557 | |
| 1558 | /* |
| 1559 | * If we stepped into a sysenter/syscall insn, it trapped in |
| 1560 | * kernel mode; do_debug() cleared TF and set TIF_SINGLESTEP. |
| 1561 | * If user-mode had set TF itself, then it's still clear from |
| 1562 | * do_debug() and we need to set it again to restore the user |
| 1563 | * state. If we entered on the slow path, TF was already set. |
| 1564 | */ |
| 1565 | if (work & _TIF_SINGLESTEP) |
| 1566 | regs->flags |= X86_EFLAGS_TF; |
| 1567 | |
| 1568 | #ifdef CONFIG_SECCOMP |
| 1569 | /* |
| 1570 | * Call seccomp_phase2 before running the other hooks so that |
| 1571 | * they can see any changes made by a seccomp tracer. |
| 1572 | */ |
| 1573 | if (phase1_result > 1 && seccomp_phase2(phase1_result)) { |
| 1574 | /* seccomp failures shouldn't expose any additional code. */ |
| 1575 | return -1; |
| 1576 | } |
| 1577 | #endif |
| 1578 | |
| 1579 | if (unlikely(work & _TIF_SYSCALL_EMU)) |
| 1580 | ret = -1L; |
| 1581 | |
| 1582 | if ((ret || test_thread_flag(TIF_SYSCALL_TRACE)) && |
| 1583 | tracehook_report_syscall_entry(regs)) |
| 1584 | ret = -1L; |
| 1585 | |
| 1586 | if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) |
| 1587 | trace_sys_enter(regs, regs->orig_ax); |
| 1588 | |
| 1589 | do_audit_syscall_entry(regs, arch); |
| 1590 | |
| 1591 | return ret ?: regs->orig_ax; |
| 1592 | } |
| 1593 | |
| 1594 | long syscall_trace_enter(struct pt_regs *regs) |
| 1595 | { |
| 1596 | u32 arch = is_ia32_task() ? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64; |
| 1597 | unsigned long phase1_result = syscall_trace_enter_phase1(regs, arch); |
| 1598 | |
| 1599 | if (phase1_result == 0) |
| 1600 | return regs->orig_ax; |
| 1601 | else |
| 1602 | return syscall_trace_enter_phase2(regs, arch, phase1_result); |
| 1603 | } |
| 1604 | |
| 1605 | void syscall_trace_leave(struct pt_regs *regs) |
| 1606 | { |
| 1607 | bool step; |
| 1608 | |
| 1609 | /* |
| 1610 | * We may come here right after calling schedule_user() |
| 1611 | * or do_notify_resume(), in which case we can be in RCU |
| 1612 | * user mode. |
| 1613 | */ |
| 1614 | user_exit(); |
| 1615 | |
| 1616 | audit_syscall_exit(regs); |
| 1617 | |
| 1618 | if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) |
| 1619 | trace_sys_exit(regs, regs->ax); |
| 1620 | |
| 1621 | /* |
| 1622 | * If TIF_SYSCALL_EMU is set, we only get here because of |
| 1623 | * TIF_SINGLESTEP (i.e. this is PTRACE_SYSEMU_SINGLESTEP). |
| 1624 | * We already reported this syscall instruction in |
| 1625 | * syscall_trace_enter(). |
| 1626 | */ |
| 1627 | step = unlikely(test_thread_flag(TIF_SINGLESTEP)) && |
| 1628 | !test_thread_flag(TIF_SYSCALL_EMU); |
| 1629 | if (step || test_thread_flag(TIF_SYSCALL_TRACE)) |
| 1630 | tracehook_report_syscall_exit(regs, step); |
| 1631 | |
| 1632 | user_enter(); |
| 1633 | } |