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v4.17
   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/sched/task_stack.h>
  10#include <linux/mm.h>
  11#include <linux/smp.h>
  12#include <linux/errno.h>
  13#include <linux/slab.h>
  14#include <linux/ptrace.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 <linux/uaccess.h>
  29#include <asm/pgtable.h>
  30#include <asm/processor.h>
  31#include <asm/fpu/internal.h>
  32#include <asm/fpu/signal.h>
  33#include <asm/fpu/regset.h>
  34#include <asm/debugreg.h>
  35#include <asm/ldt.h>
  36#include <asm/desc.h>
  37#include <asm/prctl.h>
  38#include <asm/proto.h>
  39#include <asm/hw_breakpoint.h>
  40#include <asm/traps.h>
  41#include <asm/syscall.h>
  42
  43#include "tls.h"
  44
  45enum 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
  55struct 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
  63static 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 */
 103int 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 */
 119const 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/*
 129 * does not yet catch signals sent when the child dies.
 130 * in exit.c or in signal.c.
 131 */
 132
 133/*
 134 * Determines which flags the user has access to [1 = access, 0 = no access].
 135 */
 136#define FLAG_MASK_32		((unsigned long)			\
 137				 (X86_EFLAGS_CF | X86_EFLAGS_PF |	\
 138				  X86_EFLAGS_AF | X86_EFLAGS_ZF |	\
 139				  X86_EFLAGS_SF | X86_EFLAGS_TF |	\
 140				  X86_EFLAGS_DF | X86_EFLAGS_OF |	\
 141				  X86_EFLAGS_RF | X86_EFLAGS_AC))
 142
 143/*
 144 * Determines whether a value may be installed in a segment register.
 145 */
 146static inline bool invalid_selector(u16 value)
 147{
 148	return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
 149}
 150
 151#ifdef CONFIG_X86_32
 152
 153#define FLAG_MASK		FLAG_MASK_32
 154
 155/*
 156 * X86_32 CPUs don't save ss and esp if the CPU is already in kernel mode
 157 * when it traps.  The previous stack will be directly underneath the saved
 158 * registers, and 'sp/ss' won't even have been saved. Thus the '&regs->sp'.
 159 *
 160 * Now, if the stack is empty, '&regs->sp' is out of range. In this
 161 * case we try to take the previous stack. To always return a non-null
 162 * stack pointer we fall back to regs as stack if no previous stack
 163 * exists.
 164 *
 165 * This is valid only for kernel mode traps.
 166 */
 167unsigned long kernel_stack_pointer(struct pt_regs *regs)
 168{
 169	unsigned long context = (unsigned long)regs & ~(THREAD_SIZE - 1);
 170	unsigned long sp = (unsigned long)&regs->sp;
 171	u32 *prev_esp;
 172
 173	if (context == (sp & ~(THREAD_SIZE - 1)))
 174		return sp;
 175
 176	prev_esp = (u32 *)(context);
 177	if (*prev_esp)
 178		return (unsigned long)*prev_esp;
 179
 180	return (unsigned long)regs;
 181}
 182EXPORT_SYMBOL_GPL(kernel_stack_pointer);
 183
 184static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
 185{
 186	BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
 187	return &regs->bx + (regno >> 2);
 188}
 189
 190static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 191{
 192	/*
 193	 * Returning the value truncates it to 16 bits.
 194	 */
 195	unsigned int retval;
 196	if (offset != offsetof(struct user_regs_struct, gs))
 197		retval = *pt_regs_access(task_pt_regs(task), offset);
 198	else {
 199		if (task == current)
 200			retval = get_user_gs(task_pt_regs(task));
 201		else
 202			retval = task_user_gs(task);
 203	}
 204	return retval;
 205}
 206
 207static int set_segment_reg(struct task_struct *task,
 208			   unsigned long offset, u16 value)
 209{
 210	/*
 211	 * The value argument was already truncated to 16 bits.
 212	 */
 213	if (invalid_selector(value))
 214		return -EIO;
 215
 216	/*
 217	 * For %cs and %ss we cannot permit a null selector.
 218	 * We can permit a bogus selector as long as it has USER_RPL.
 219	 * Null selectors are fine for other segment registers, but
 220	 * we will never get back to user mode with invalid %cs or %ss
 221	 * and will take the trap in iret instead.  Much code relies
 222	 * on user_mode() to distinguish a user trap frame (which can
 223	 * safely use invalid selectors) from a kernel trap frame.
 224	 */
 225	switch (offset) {
 226	case offsetof(struct user_regs_struct, cs):
 227	case offsetof(struct user_regs_struct, ss):
 228		if (unlikely(value == 0))
 229			return -EIO;
 230
 231	default:
 232		*pt_regs_access(task_pt_regs(task), offset) = value;
 233		break;
 234
 235	case offsetof(struct user_regs_struct, gs):
 236		if (task == current)
 237			set_user_gs(task_pt_regs(task), value);
 238		else
 239			task_user_gs(task) = value;
 240	}
 241
 242	return 0;
 243}
 244
 245#else  /* CONFIG_X86_64 */
 246
 247#define FLAG_MASK		(FLAG_MASK_32 | X86_EFLAGS_NT)
 248
 249static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
 250{
 251	BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
 252	return &regs->r15 + (offset / sizeof(regs->r15));
 253}
 254
 255static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 256{
 257	/*
 258	 * Returning the value truncates it to 16 bits.
 259	 */
 260	unsigned int seg;
 261
 262	switch (offset) {
 263	case offsetof(struct user_regs_struct, fs):
 264		if (task == current) {
 265			/* Older gas can't assemble movq %?s,%r?? */
 266			asm("movl %%fs,%0" : "=r" (seg));
 267			return seg;
 268		}
 269		return task->thread.fsindex;
 270	case offsetof(struct user_regs_struct, gs):
 271		if (task == current) {
 272			asm("movl %%gs,%0" : "=r" (seg));
 273			return seg;
 274		}
 275		return task->thread.gsindex;
 276	case offsetof(struct user_regs_struct, ds):
 277		if (task == current) {
 278			asm("movl %%ds,%0" : "=r" (seg));
 279			return seg;
 280		}
 281		return task->thread.ds;
 282	case offsetof(struct user_regs_struct, es):
 283		if (task == current) {
 284			asm("movl %%es,%0" : "=r" (seg));
 285			return seg;
 286		}
 287		return task->thread.es;
 288
 289	case offsetof(struct user_regs_struct, cs):
 290	case offsetof(struct user_regs_struct, ss):
 291		break;
 292	}
 293	return *pt_regs_access(task_pt_regs(task), offset);
 294}
 295
 296static int set_segment_reg(struct task_struct *task,
 297			   unsigned long offset, u16 value)
 298{
 299	/*
 300	 * The value argument was already truncated to 16 bits.
 301	 */
 302	if (invalid_selector(value))
 303		return -EIO;
 304
 305	switch (offset) {
 306	case offsetof(struct user_regs_struct,fs):
 307		task->thread.fsindex = value;
 308		if (task == current)
 309			loadsegment(fs, task->thread.fsindex);
 310		break;
 311	case offsetof(struct user_regs_struct,gs):
 312		task->thread.gsindex = value;
 313		if (task == current)
 314			load_gs_index(task->thread.gsindex);
 315		break;
 316	case offsetof(struct user_regs_struct,ds):
 317		task->thread.ds = value;
 318		if (task == current)
 319			loadsegment(ds, task->thread.ds);
 320		break;
 321	case offsetof(struct user_regs_struct,es):
 322		task->thread.es = value;
 323		if (task == current)
 324			loadsegment(es, task->thread.es);
 325		break;
 326
 327		/*
 328		 * Can't actually change these in 64-bit mode.
 329		 */
 330	case offsetof(struct user_regs_struct,cs):
 331		if (unlikely(value == 0))
 332			return -EIO;
 333		task_pt_regs(task)->cs = value;
 334		break;
 335	case offsetof(struct user_regs_struct,ss):
 336		if (unlikely(value == 0))
 337			return -EIO;
 338		task_pt_regs(task)->ss = value;
 339		break;
 340	}
 341
 342	return 0;
 343}
 344
 345#endif	/* CONFIG_X86_32 */
 346
 347static unsigned long get_flags(struct task_struct *task)
 348{
 349	unsigned long retval = task_pt_regs(task)->flags;
 350
 351	/*
 352	 * If the debugger set TF, hide it from the readout.
 353	 */
 354	if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 355		retval &= ~X86_EFLAGS_TF;
 356
 357	return retval;
 358}
 359
 360static int set_flags(struct task_struct *task, unsigned long value)
 361{
 362	struct pt_regs *regs = task_pt_regs(task);
 363
 364	/*
 365	 * If the user value contains TF, mark that
 366	 * it was not "us" (the debugger) that set it.
 367	 * If not, make sure it stays set if we had.
 368	 */
 369	if (value & X86_EFLAGS_TF)
 370		clear_tsk_thread_flag(task, TIF_FORCED_TF);
 371	else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 372		value |= X86_EFLAGS_TF;
 373
 374	regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
 375
 376	return 0;
 377}
 378
 379static int putreg(struct task_struct *child,
 380		  unsigned long offset, unsigned long value)
 381{
 382	switch (offset) {
 383	case offsetof(struct user_regs_struct, cs):
 384	case offsetof(struct user_regs_struct, ds):
 385	case offsetof(struct user_regs_struct, es):
 386	case offsetof(struct user_regs_struct, fs):
 387	case offsetof(struct user_regs_struct, gs):
 388	case offsetof(struct user_regs_struct, ss):
 389		return set_segment_reg(child, offset, value);
 390
 391	case offsetof(struct user_regs_struct, flags):
 392		return set_flags(child, value);
 393
 394#ifdef CONFIG_X86_64
 395	case offsetof(struct user_regs_struct,fs_base):
 396		if (value >= TASK_SIZE_MAX)
 397			return -EIO;
 398		/*
 399		 * When changing the segment base, use do_arch_prctl_64
 400		 * to set either thread.fs or thread.fsindex and the
 401		 * corresponding GDT slot.
 402		 */
 403		if (child->thread.fsbase != value)
 404			return do_arch_prctl_64(child, ARCH_SET_FS, value);
 405		return 0;
 406	case offsetof(struct user_regs_struct,gs_base):
 407		/*
 408		 * Exactly the same here as the %fs handling above.
 409		 */
 410		if (value >= TASK_SIZE_MAX)
 411			return -EIO;
 412		if (child->thread.gsbase != value)
 413			return do_arch_prctl_64(child, ARCH_SET_GS, value);
 414		return 0;
 415#endif
 416	}
 417
 418	*pt_regs_access(task_pt_regs(child), offset) = value;
 419	return 0;
 420}
 421
 422static unsigned long getreg(struct task_struct *task, unsigned long offset)
 423{
 424	switch (offset) {
 425	case offsetof(struct user_regs_struct, cs):
 426	case offsetof(struct user_regs_struct, ds):
 427	case offsetof(struct user_regs_struct, es):
 428	case offsetof(struct user_regs_struct, fs):
 429	case offsetof(struct user_regs_struct, gs):
 430	case offsetof(struct user_regs_struct, ss):
 431		return get_segment_reg(task, offset);
 432
 433	case offsetof(struct user_regs_struct, flags):
 434		return get_flags(task);
 435
 436#ifdef CONFIG_X86_64
 437	case offsetof(struct user_regs_struct, fs_base): {
 438		/*
 439		 * XXX: This will not behave as expected if called on
 440		 * current or if fsindex != 0.
 441		 */
 442		return task->thread.fsbase;
 443	}
 444	case offsetof(struct user_regs_struct, gs_base): {
 445		/*
 446		 * XXX: This will not behave as expected if called on
 447		 * current or if fsindex != 0.
 448		 */
 449		return task->thread.gsbase;
 450	}
 451#endif
 452	}
 453
 454	return *pt_regs_access(task_pt_regs(task), offset);
 455}
 456
 457static int genregs_get(struct task_struct *target,
 458		       const struct user_regset *regset,
 459		       unsigned int pos, unsigned int count,
 460		       void *kbuf, void __user *ubuf)
 461{
 462	if (kbuf) {
 463		unsigned long *k = kbuf;
 464		while (count >= sizeof(*k)) {
 465			*k++ = getreg(target, pos);
 466			count -= sizeof(*k);
 467			pos += sizeof(*k);
 468		}
 469	} else {
 470		unsigned long __user *u = ubuf;
 471		while (count >= sizeof(*u)) {
 472			if (__put_user(getreg(target, pos), u++))
 473				return -EFAULT;
 474			count -= sizeof(*u);
 475			pos += sizeof(*u);
 476		}
 477	}
 478
 479	return 0;
 480}
 481
 482static int genregs_set(struct task_struct *target,
 483		       const struct user_regset *regset,
 484		       unsigned int pos, unsigned int count,
 485		       const void *kbuf, const void __user *ubuf)
 486{
 487	int ret = 0;
 488	if (kbuf) {
 489		const unsigned long *k = kbuf;
 490		while (count >= sizeof(*k) && !ret) {
 491			ret = putreg(target, pos, *k++);
 492			count -= sizeof(*k);
 493			pos += sizeof(*k);
 494		}
 495	} else {
 496		const unsigned long  __user *u = ubuf;
 497		while (count >= sizeof(*u) && !ret) {
 498			unsigned long word;
 499			ret = __get_user(word, u++);
 500			if (ret)
 501				break;
 502			ret = putreg(target, pos, word);
 503			count -= sizeof(*u);
 504			pos += sizeof(*u);
 505		}
 506	}
 507	return ret;
 508}
 509
 510static void ptrace_triggered(struct perf_event *bp,
 511			     struct perf_sample_data *data,
 512			     struct pt_regs *regs)
 513{
 514	int i;
 515	struct thread_struct *thread = &(current->thread);
 516
 517	/*
 518	 * Store in the virtual DR6 register the fact that the breakpoint
 519	 * was hit so the thread's debugger will see it.
 520	 */
 521	for (i = 0; i < HBP_NUM; i++) {
 522		if (thread->ptrace_bps[i] == bp)
 523			break;
 524	}
 525
 526	thread->debugreg6 |= (DR_TRAP0 << i);
 527}
 528
 529/*
 530 * Walk through every ptrace breakpoints for this thread and
 531 * build the dr7 value on top of their attributes.
 532 *
 533 */
 534static unsigned long ptrace_get_dr7(struct perf_event *bp[])
 535{
 536	int i;
 537	int dr7 = 0;
 538	struct arch_hw_breakpoint *info;
 539
 540	for (i = 0; i < HBP_NUM; i++) {
 541		if (bp[i] && !bp[i]->attr.disabled) {
 542			info = counter_arch_bp(bp[i]);
 543			dr7 |= encode_dr7(i, info->len, info->type);
 544		}
 545	}
 546
 547	return dr7;
 548}
 549
 550static int ptrace_fill_bp_fields(struct perf_event_attr *attr,
 551					int len, int type, bool disabled)
 552{
 553	int err, bp_len, bp_type;
 554
 555	err = arch_bp_generic_fields(len, type, &bp_len, &bp_type);
 556	if (!err) {
 557		attr->bp_len = bp_len;
 558		attr->bp_type = bp_type;
 559		attr->disabled = disabled;
 560	}
 561
 562	return err;
 563}
 564
 565static struct perf_event *
 566ptrace_register_breakpoint(struct task_struct *tsk, int len, int type,
 567				unsigned long addr, bool disabled)
 568{
 569	struct perf_event_attr attr;
 570	int err;
 571
 572	ptrace_breakpoint_init(&attr);
 573	attr.bp_addr = addr;
 574
 575	err = ptrace_fill_bp_fields(&attr, len, type, disabled);
 576	if (err)
 577		return ERR_PTR(err);
 578
 579	return register_user_hw_breakpoint(&attr, ptrace_triggered,
 580						 NULL, tsk);
 581}
 582
 583static int ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
 584					int disabled)
 585{
 586	struct perf_event_attr attr = bp->attr;
 587	int err;
 588
 589	err = ptrace_fill_bp_fields(&attr, len, type, disabled);
 590	if (err)
 591		return err;
 592
 593	return modify_user_hw_breakpoint(bp, &attr);
 594}
 595
 596/*
 597 * Handle ptrace writes to debug register 7.
 598 */
 599static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
 600{
 601	struct thread_struct *thread = &tsk->thread;
 602	unsigned long old_dr7;
 603	bool second_pass = false;
 604	int i, rc, ret = 0;
 605
 606	data &= ~DR_CONTROL_RESERVED;
 607	old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
 608
 609restore:
 610	rc = 0;
 611	for (i = 0; i < HBP_NUM; i++) {
 612		unsigned len, type;
 613		bool disabled = !decode_dr7(data, i, &len, &type);
 614		struct perf_event *bp = thread->ptrace_bps[i];
 615
 616		if (!bp) {
 617			if (disabled)
 618				continue;
 619
 620			bp = ptrace_register_breakpoint(tsk,
 621					len, type, 0, disabled);
 622			if (IS_ERR(bp)) {
 623				rc = PTR_ERR(bp);
 624				break;
 625			}
 626
 627			thread->ptrace_bps[i] = bp;
 628			continue;
 629		}
 630
 631		rc = ptrace_modify_breakpoint(bp, len, type, disabled);
 632		if (rc)
 633			break;
 634	}
 635
 636	/* Restore if the first pass failed, second_pass shouldn't fail. */
 637	if (rc && !WARN_ON(second_pass)) {
 638		ret = rc;
 639		data = old_dr7;
 640		second_pass = true;
 641		goto restore;
 642	}
 643
 644	return ret;
 645}
 646
 647/*
 648 * Handle PTRACE_PEEKUSR calls for the debug register area.
 649 */
 650static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
 651{
 652	struct thread_struct *thread = &tsk->thread;
 653	unsigned long val = 0;
 654
 655	if (n < HBP_NUM) {
 656		struct perf_event *bp = thread->ptrace_bps[n];
 657
 658		if (bp)
 659			val = bp->hw.info.address;
 660	} else if (n == 6) {
 661		val = thread->debugreg6;
 662	} else if (n == 7) {
 663		val = thread->ptrace_dr7;
 664	}
 665	return val;
 666}
 667
 668static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
 669				      unsigned long addr)
 670{
 671	struct thread_struct *t = &tsk->thread;
 672	struct perf_event *bp = t->ptrace_bps[nr];
 673	int err = 0;
 674
 675	if (!bp) {
 676		/*
 677		 * Put stub len and type to create an inactive but correct bp.
 678		 *
 679		 * CHECKME: the previous code returned -EIO if the addr wasn't
 680		 * a valid task virtual addr. The new one will return -EINVAL in
 681		 *  this case.
 682		 * -EINVAL may be what we want for in-kernel breakpoints users,
 683		 * but -EIO looks better for ptrace, since we refuse a register
 684		 * writing for the user. And anyway this is the previous
 685		 * behaviour.
 686		 */
 687		bp = ptrace_register_breakpoint(tsk,
 688				X86_BREAKPOINT_LEN_1, X86_BREAKPOINT_WRITE,
 689				addr, true);
 690		if (IS_ERR(bp))
 691			err = PTR_ERR(bp);
 692		else
 693			t->ptrace_bps[nr] = bp;
 694	} else {
 695		struct perf_event_attr attr = bp->attr;
 696
 697		attr.bp_addr = addr;
 698		err = modify_user_hw_breakpoint(bp, &attr);
 699	}
 700
 701	return err;
 702}
 703
 704/*
 705 * Handle PTRACE_POKEUSR calls for the debug register area.
 706 */
 707static int ptrace_set_debugreg(struct task_struct *tsk, int n,
 708			       unsigned long val)
 709{
 710	struct thread_struct *thread = &tsk->thread;
 711	/* There are no DR4 or DR5 registers */
 712	int rc = -EIO;
 713
 714	if (n < HBP_NUM) {
 715		rc = ptrace_set_breakpoint_addr(tsk, n, val);
 716	} else if (n == 6) {
 717		thread->debugreg6 = val;
 718		rc = 0;
 719	} else if (n == 7) {
 720		rc = ptrace_write_dr7(tsk, val);
 721		if (!rc)
 722			thread->ptrace_dr7 = val;
 723	}
 724	return rc;
 725}
 726
 727/*
 728 * These access the current or another (stopped) task's io permission
 729 * bitmap for debugging or core dump.
 730 */
 731static int ioperm_active(struct task_struct *target,
 732			 const struct user_regset *regset)
 733{
 734	return target->thread.io_bitmap_max / regset->size;
 735}
 736
 737static int ioperm_get(struct task_struct *target,
 738		      const struct user_regset *regset,
 739		      unsigned int pos, unsigned int count,
 740		      void *kbuf, void __user *ubuf)
 741{
 742	if (!target->thread.io_bitmap_ptr)
 743		return -ENXIO;
 744
 745	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 746				   target->thread.io_bitmap_ptr,
 747				   0, IO_BITMAP_BYTES);
 748}
 749
 750/*
 751 * Called by kernel/ptrace.c when detaching..
 752 *
 753 * Make sure the single step bit is not set.
 754 */
 755void ptrace_disable(struct task_struct *child)
 756{
 757	user_disable_single_step(child);
 758#ifdef TIF_SYSCALL_EMU
 759	clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
 760#endif
 761}
 762
 763#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 764static const struct user_regset_view user_x86_32_view; /* Initialized below. */
 765#endif
 766
 767long arch_ptrace(struct task_struct *child, long request,
 768		 unsigned long addr, unsigned long data)
 769{
 770	int ret;
 771	unsigned long __user *datap = (unsigned long __user *)data;
 772
 773	switch (request) {
 774	/* read the word at location addr in the USER area. */
 775	case PTRACE_PEEKUSR: {
 776		unsigned long tmp;
 777
 778		ret = -EIO;
 779		if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 780			break;
 781
 782		tmp = 0;  /* Default return condition */
 783		if (addr < sizeof(struct user_regs_struct))
 784			tmp = getreg(child, addr);
 785		else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 786			 addr <= offsetof(struct user, u_debugreg[7])) {
 787			addr -= offsetof(struct user, u_debugreg[0]);
 788			tmp = ptrace_get_debugreg(child, addr / sizeof(data));
 789		}
 790		ret = put_user(tmp, datap);
 791		break;
 792	}
 793
 794	case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
 795		ret = -EIO;
 796		if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 797			break;
 798
 799		if (addr < sizeof(struct user_regs_struct))
 800			ret = putreg(child, addr, data);
 801		else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 802			 addr <= offsetof(struct user, u_debugreg[7])) {
 803			addr -= offsetof(struct user, u_debugreg[0]);
 804			ret = ptrace_set_debugreg(child,
 805						  addr / sizeof(data), data);
 806		}
 807		break;
 808
 809	case PTRACE_GETREGS:	/* Get all gp regs from the child. */
 810		return copy_regset_to_user(child,
 811					   task_user_regset_view(current),
 812					   REGSET_GENERAL,
 813					   0, sizeof(struct user_regs_struct),
 814					   datap);
 815
 816	case PTRACE_SETREGS:	/* Set all gp regs in the child. */
 817		return copy_regset_from_user(child,
 818					     task_user_regset_view(current),
 819					     REGSET_GENERAL,
 820					     0, sizeof(struct user_regs_struct),
 821					     datap);
 822
 823	case PTRACE_GETFPREGS:	/* Get the child FPU state. */
 824		return copy_regset_to_user(child,
 825					   task_user_regset_view(current),
 826					   REGSET_FP,
 827					   0, sizeof(struct user_i387_struct),
 828					   datap);
 829
 830	case PTRACE_SETFPREGS:	/* Set the child FPU state. */
 831		return copy_regset_from_user(child,
 832					     task_user_regset_view(current),
 833					     REGSET_FP,
 834					     0, sizeof(struct user_i387_struct),
 835					     datap);
 836
 837#ifdef CONFIG_X86_32
 838	case PTRACE_GETFPXREGS:	/* Get the child extended FPU state. */
 839		return copy_regset_to_user(child, &user_x86_32_view,
 840					   REGSET_XFP,
 841					   0, sizeof(struct user_fxsr_struct),
 842					   datap) ? -EIO : 0;
 843
 844	case PTRACE_SETFPXREGS:	/* Set the child extended FPU state. */
 845		return copy_regset_from_user(child, &user_x86_32_view,
 846					     REGSET_XFP,
 847					     0, sizeof(struct user_fxsr_struct),
 848					     datap) ? -EIO : 0;
 849#endif
 850
 851#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 852	case PTRACE_GET_THREAD_AREA:
 853		if ((int) addr < 0)
 854			return -EIO;
 855		ret = do_get_thread_area(child, addr,
 856					(struct user_desc __user *)data);
 857		break;
 858
 859	case PTRACE_SET_THREAD_AREA:
 860		if ((int) addr < 0)
 861			return -EIO;
 862		ret = do_set_thread_area(child, addr,
 863					(struct user_desc __user *)data, 0);
 864		break;
 865#endif
 866
 867#ifdef CONFIG_X86_64
 868		/* normal 64bit interface to access TLS data.
 869		   Works just like arch_prctl, except that the arguments
 870		   are reversed. */
 871	case PTRACE_ARCH_PRCTL:
 872		ret = do_arch_prctl_64(child, data, addr);
 873		break;
 874#endif
 875
 876	default:
 877		ret = ptrace_request(child, request, addr, data);
 878		break;
 879	}
 880
 881	return ret;
 882}
 883
 884#ifdef CONFIG_IA32_EMULATION
 885
 886#include <linux/compat.h>
 887#include <linux/syscalls.h>
 888#include <asm/ia32.h>
 889#include <asm/user32.h>
 890
 891#define R32(l,q)							\
 892	case offsetof(struct user32, regs.l):				\
 893		regs->q = value; break
 894
 895#define SEG32(rs)							\
 896	case offsetof(struct user32, regs.rs):				\
 897		return set_segment_reg(child,				\
 898				       offsetof(struct user_regs_struct, rs), \
 899				       value);				\
 900		break
 901
 902static int putreg32(struct task_struct *child, unsigned regno, u32 value)
 903{
 904	struct pt_regs *regs = task_pt_regs(child);
 905
 906	switch (regno) {
 907
 908	SEG32(cs);
 909	SEG32(ds);
 910	SEG32(es);
 911	SEG32(fs);
 912	SEG32(gs);
 913	SEG32(ss);
 914
 915	R32(ebx, bx);
 916	R32(ecx, cx);
 917	R32(edx, dx);
 918	R32(edi, di);
 919	R32(esi, si);
 920	R32(ebp, bp);
 921	R32(eax, ax);
 922	R32(eip, ip);
 923	R32(esp, sp);
 924
 925	case offsetof(struct user32, regs.orig_eax):
 926		/*
 927		 * Warning: bizarre corner case fixup here.  A 32-bit
 928		 * debugger setting orig_eax to -1 wants to disable
 929		 * syscall restart.  Make sure that the syscall
 930		 * restart code sign-extends orig_ax.  Also make sure
 931		 * we interpret the -ERESTART* codes correctly if
 932		 * loaded into regs->ax in case the task is not
 933		 * actually still sitting at the exit from a 32-bit
 934		 * syscall with TS_COMPAT still set.
 935		 */
 936		regs->orig_ax = value;
 937		if (syscall_get_nr(child, regs) >= 0)
 938			child->thread_info.status |= TS_I386_REGS_POKED;
 939		break;
 940
 941	case offsetof(struct user32, regs.eflags):
 942		return set_flags(child, value);
 943
 944	case offsetof(struct user32, u_debugreg[0]) ...
 945		offsetof(struct user32, u_debugreg[7]):
 946		regno -= offsetof(struct user32, u_debugreg[0]);
 947		return ptrace_set_debugreg(child, regno / 4, value);
 948
 949	default:
 950		if (regno > sizeof(struct user32) || (regno & 3))
 951			return -EIO;
 952
 953		/*
 954		 * Other dummy fields in the virtual user structure
 955		 * are ignored
 956		 */
 957		break;
 958	}
 959	return 0;
 960}
 961
 962#undef R32
 963#undef SEG32
 964
 965#define R32(l,q)							\
 966	case offsetof(struct user32, regs.l):				\
 967		*val = regs->q; break
 968
 969#define SEG32(rs)							\
 970	case offsetof(struct user32, regs.rs):				\
 971		*val = get_segment_reg(child,				\
 972				       offsetof(struct user_regs_struct, rs)); \
 973		break
 974
 975static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
 976{
 977	struct pt_regs *regs = task_pt_regs(child);
 978
 979	switch (regno) {
 980
 981	SEG32(ds);
 982	SEG32(es);
 983	SEG32(fs);
 984	SEG32(gs);
 985
 986	R32(cs, cs);
 987	R32(ss, ss);
 988	R32(ebx, bx);
 989	R32(ecx, cx);
 990	R32(edx, dx);
 991	R32(edi, di);
 992	R32(esi, si);
 993	R32(ebp, bp);
 994	R32(eax, ax);
 995	R32(orig_eax, orig_ax);
 996	R32(eip, ip);
 997	R32(esp, sp);
 998
 999	case offsetof(struct user32, regs.eflags):
1000		*val = get_flags(child);
1001		break;
1002
1003	case offsetof(struct user32, u_debugreg[0]) ...
1004		offsetof(struct user32, u_debugreg[7]):
1005		regno -= offsetof(struct user32, u_debugreg[0]);
1006		*val = ptrace_get_debugreg(child, regno / 4);
1007		break;
1008
1009	default:
1010		if (regno > sizeof(struct user32) || (regno & 3))
1011			return -EIO;
1012
1013		/*
1014		 * Other dummy fields in the virtual user structure
1015		 * are ignored
1016		 */
1017		*val = 0;
1018		break;
1019	}
1020	return 0;
1021}
1022
1023#undef R32
1024#undef SEG32
1025
1026static int genregs32_get(struct task_struct *target,
1027			 const struct user_regset *regset,
1028			 unsigned int pos, unsigned int count,
1029			 void *kbuf, void __user *ubuf)
1030{
1031	if (kbuf) {
1032		compat_ulong_t *k = kbuf;
1033		while (count >= sizeof(*k)) {
1034			getreg32(target, pos, k++);
1035			count -= sizeof(*k);
1036			pos += sizeof(*k);
1037		}
1038	} else {
1039		compat_ulong_t __user *u = ubuf;
1040		while (count >= sizeof(*u)) {
1041			compat_ulong_t word;
1042			getreg32(target, pos, &word);
1043			if (__put_user(word, u++))
1044				return -EFAULT;
1045			count -= sizeof(*u);
1046			pos += sizeof(*u);
1047		}
1048	}
1049
1050	return 0;
1051}
1052
1053static int genregs32_set(struct task_struct *target,
1054			 const struct user_regset *regset,
1055			 unsigned int pos, unsigned int count,
1056			 const void *kbuf, const void __user *ubuf)
1057{
1058	int ret = 0;
1059	if (kbuf) {
1060		const compat_ulong_t *k = kbuf;
1061		while (count >= sizeof(*k) && !ret) {
1062			ret = putreg32(target, pos, *k++);
1063			count -= sizeof(*k);
1064			pos += sizeof(*k);
1065		}
1066	} else {
1067		const compat_ulong_t __user *u = ubuf;
1068		while (count >= sizeof(*u) && !ret) {
1069			compat_ulong_t word;
1070			ret = __get_user(word, u++);
1071			if (ret)
1072				break;
1073			ret = putreg32(target, pos, word);
1074			count -= sizeof(*u);
1075			pos += sizeof(*u);
1076		}
1077	}
1078	return ret;
1079}
1080
1081static long ia32_arch_ptrace(struct task_struct *child, compat_long_t request,
1082			     compat_ulong_t caddr, compat_ulong_t cdata)
1083{
1084	unsigned long addr = caddr;
1085	unsigned long data = cdata;
1086	void __user *datap = compat_ptr(data);
1087	int ret;
1088	__u32 val;
1089
1090	switch (request) {
1091	case PTRACE_PEEKUSR:
1092		ret = getreg32(child, addr, &val);
1093		if (ret == 0)
1094			ret = put_user(val, (__u32 __user *)datap);
1095		break;
1096
1097	case PTRACE_POKEUSR:
1098		ret = putreg32(child, addr, data);
1099		break;
1100
1101	case PTRACE_GETREGS:	/* Get all gp regs from the child. */
1102		return copy_regset_to_user(child, &user_x86_32_view,
1103					   REGSET_GENERAL,
1104					   0, sizeof(struct user_regs_struct32),
1105					   datap);
1106
1107	case PTRACE_SETREGS:	/* Set all gp regs in the child. */
1108		return copy_regset_from_user(child, &user_x86_32_view,
1109					     REGSET_GENERAL, 0,
1110					     sizeof(struct user_regs_struct32),
1111					     datap);
1112
1113	case PTRACE_GETFPREGS:	/* Get the child FPU state. */
1114		return copy_regset_to_user(child, &user_x86_32_view,
1115					   REGSET_FP, 0,
1116					   sizeof(struct user_i387_ia32_struct),
1117					   datap);
1118
1119	case PTRACE_SETFPREGS:	/* Set the child FPU state. */
1120		return copy_regset_from_user(
1121			child, &user_x86_32_view, REGSET_FP,
1122			0, sizeof(struct user_i387_ia32_struct), datap);
1123
1124	case PTRACE_GETFPXREGS:	/* Get the child extended FPU state. */
1125		return copy_regset_to_user(child, &user_x86_32_view,
1126					   REGSET_XFP, 0,
1127					   sizeof(struct user32_fxsr_struct),
1128					   datap);
1129
1130	case PTRACE_SETFPXREGS:	/* Set the child extended FPU state. */
1131		return copy_regset_from_user(child, &user_x86_32_view,
1132					     REGSET_XFP, 0,
1133					     sizeof(struct user32_fxsr_struct),
1134					     datap);
1135
1136	case PTRACE_GET_THREAD_AREA:
1137	case PTRACE_SET_THREAD_AREA:
1138		return arch_ptrace(child, request, addr, data);
1139
1140	default:
1141		return compat_ptrace_request(child, request, addr, data);
1142	}
1143
1144	return ret;
1145}
1146#endif /* CONFIG_IA32_EMULATION */
1147
1148#ifdef CONFIG_X86_X32_ABI
1149static long x32_arch_ptrace(struct task_struct *child,
1150			    compat_long_t request, compat_ulong_t caddr,
1151			    compat_ulong_t cdata)
1152{
1153	unsigned long addr = caddr;
1154	unsigned long data = cdata;
1155	void __user *datap = compat_ptr(data);
1156	int ret;
1157
1158	switch (request) {
1159	/* Read 32bits at location addr in the USER area.  Only allow
1160	   to return the lower 32bits of segment and debug registers.  */
1161	case PTRACE_PEEKUSR: {
1162		u32 tmp;
1163
1164		ret = -EIO;
1165		if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1166		    addr < offsetof(struct user_regs_struct, cs))
1167			break;
1168
1169		tmp = 0;  /* Default return condition */
1170		if (addr < sizeof(struct user_regs_struct))
1171			tmp = getreg(child, addr);
1172		else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1173			 addr <= offsetof(struct user, u_debugreg[7])) {
1174			addr -= offsetof(struct user, u_debugreg[0]);
1175			tmp = ptrace_get_debugreg(child, addr / sizeof(data));
1176		}
1177		ret = put_user(tmp, (__u32 __user *)datap);
1178		break;
1179	}
1180
1181	/* Write the word at location addr in the USER area.  Only allow
1182	   to update segment and debug registers with the upper 32bits
1183	   zero-extended. */
1184	case PTRACE_POKEUSR:
1185		ret = -EIO;
1186		if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1187		    addr < offsetof(struct user_regs_struct, cs))
1188			break;
1189
1190		if (addr < sizeof(struct user_regs_struct))
1191			ret = putreg(child, addr, data);
1192		else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1193			 addr <= offsetof(struct user, u_debugreg[7])) {
1194			addr -= offsetof(struct user, u_debugreg[0]);
1195			ret = ptrace_set_debugreg(child,
1196						  addr / sizeof(data), data);
1197		}
1198		break;
1199
1200	case PTRACE_GETREGS:	/* Get all gp regs from the child. */
1201		return copy_regset_to_user(child,
1202					   task_user_regset_view(current),
1203					   REGSET_GENERAL,
1204					   0, sizeof(struct user_regs_struct),
1205					   datap);
1206
1207	case PTRACE_SETREGS:	/* Set all gp regs in the child. */
1208		return copy_regset_from_user(child,
1209					     task_user_regset_view(current),
1210					     REGSET_GENERAL,
1211					     0, sizeof(struct user_regs_struct),
1212					     datap);
1213
1214	case PTRACE_GETFPREGS:	/* Get the child FPU state. */
1215		return copy_regset_to_user(child,
1216					   task_user_regset_view(current),
1217					   REGSET_FP,
1218					   0, sizeof(struct user_i387_struct),
1219					   datap);
1220
1221	case PTRACE_SETFPREGS:	/* Set the child FPU state. */
1222		return copy_regset_from_user(child,
1223					     task_user_regset_view(current),
1224					     REGSET_FP,
1225					     0, sizeof(struct user_i387_struct),
1226					     datap);
1227
1228	default:
1229		return compat_ptrace_request(child, request, addr, data);
1230	}
1231
1232	return ret;
1233}
1234#endif
1235
1236#ifdef CONFIG_COMPAT
1237long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1238			compat_ulong_t caddr, compat_ulong_t cdata)
1239{
1240#ifdef CONFIG_X86_X32_ABI
1241	if (!in_ia32_syscall())
1242		return x32_arch_ptrace(child, request, caddr, cdata);
1243#endif
1244#ifdef CONFIG_IA32_EMULATION
1245	return ia32_arch_ptrace(child, request, caddr, cdata);
1246#else
1247	return 0;
1248#endif
1249}
1250#endif	/* CONFIG_COMPAT */
1251
1252#ifdef CONFIG_X86_64
1253
1254static struct user_regset x86_64_regsets[] __ro_after_init = {
1255	[REGSET_GENERAL] = {
1256		.core_note_type = NT_PRSTATUS,
1257		.n = sizeof(struct user_regs_struct) / sizeof(long),
1258		.size = sizeof(long), .align = sizeof(long),
1259		.get = genregs_get, .set = genregs_set
1260	},
1261	[REGSET_FP] = {
1262		.core_note_type = NT_PRFPREG,
1263		.n = sizeof(struct user_i387_struct) / sizeof(long),
1264		.size = sizeof(long), .align = sizeof(long),
1265		.active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1266	},
1267	[REGSET_XSTATE] = {
1268		.core_note_type = NT_X86_XSTATE,
1269		.size = sizeof(u64), .align = sizeof(u64),
1270		.active = xstateregs_active, .get = xstateregs_get,
1271		.set = xstateregs_set
1272	},
1273	[REGSET_IOPERM64] = {
1274		.core_note_type = NT_386_IOPERM,
1275		.n = IO_BITMAP_LONGS,
1276		.size = sizeof(long), .align = sizeof(long),
1277		.active = ioperm_active, .get = ioperm_get
1278	},
1279};
1280
1281static const struct user_regset_view user_x86_64_view = {
1282	.name = "x86_64", .e_machine = EM_X86_64,
1283	.regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1284};
1285
1286#else  /* CONFIG_X86_32 */
1287
1288#define user_regs_struct32	user_regs_struct
1289#define genregs32_get		genregs_get
1290#define genregs32_set		genregs_set
1291
1292#endif	/* CONFIG_X86_64 */
1293
1294#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1295static struct user_regset x86_32_regsets[] __ro_after_init = {
1296	[REGSET_GENERAL] = {
1297		.core_note_type = NT_PRSTATUS,
1298		.n = sizeof(struct user_regs_struct32) / sizeof(u32),
1299		.size = sizeof(u32), .align = sizeof(u32),
1300		.get = genregs32_get, .set = genregs32_set
1301	},
1302	[REGSET_FP] = {
1303		.core_note_type = NT_PRFPREG,
1304		.n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1305		.size = sizeof(u32), .align = sizeof(u32),
1306		.active = regset_fpregs_active, .get = fpregs_get, .set = fpregs_set
1307	},
1308	[REGSET_XFP] = {
1309		.core_note_type = NT_PRXFPREG,
1310		.n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1311		.size = sizeof(u32), .align = sizeof(u32),
1312		.active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1313	},
1314	[REGSET_XSTATE] = {
1315		.core_note_type = NT_X86_XSTATE,
1316		.size = sizeof(u64), .align = sizeof(u64),
1317		.active = xstateregs_active, .get = xstateregs_get,
1318		.set = xstateregs_set
1319	},
1320	[REGSET_TLS] = {
1321		.core_note_type = NT_386_TLS,
1322		.n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1323		.size = sizeof(struct user_desc),
1324		.align = sizeof(struct user_desc),
1325		.active = regset_tls_active,
1326		.get = regset_tls_get, .set = regset_tls_set
1327	},
1328	[REGSET_IOPERM32] = {
1329		.core_note_type = NT_386_IOPERM,
1330		.n = IO_BITMAP_BYTES / sizeof(u32),
1331		.size = sizeof(u32), .align = sizeof(u32),
1332		.active = ioperm_active, .get = ioperm_get
1333	},
1334};
1335
1336static const struct user_regset_view user_x86_32_view = {
1337	.name = "i386", .e_machine = EM_386,
1338	.regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1339};
1340#endif
1341
1342/*
1343 * This represents bytes 464..511 in the memory layout exported through
1344 * the REGSET_XSTATE interface.
1345 */
1346u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1347
1348void __init update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1349{
1350#ifdef CONFIG_X86_64
1351	x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1352#endif
1353#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1354	x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1355#endif
1356	xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1357}
1358
1359const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1360{
1361#ifdef CONFIG_IA32_EMULATION
1362	if (!user_64bit_mode(task_pt_regs(task)))
1363#endif
1364#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1365		return &user_x86_32_view;
1366#endif
1367#ifdef CONFIG_X86_64
1368	return &user_x86_64_view;
1369#endif
1370}
1371
1372static void fill_sigtrap_info(struct task_struct *tsk,
1373				struct pt_regs *regs,
1374				int error_code, int si_code,
1375				struct siginfo *info)
1376{
1377	tsk->thread.trap_nr = X86_TRAP_DB;
1378	tsk->thread.error_code = error_code;
1379
1380	memset(info, 0, sizeof(*info));
1381	info->si_signo = SIGTRAP;
1382	info->si_code = si_code;
1383	info->si_addr = user_mode(regs) ? (void __user *)regs->ip : NULL;
1384}
1385
1386void user_single_step_siginfo(struct task_struct *tsk,
1387				struct pt_regs *regs,
1388				struct siginfo *info)
1389{
1390	fill_sigtrap_info(tsk, regs, 0, TRAP_BRKPT, info);
1391}
1392
1393void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
1394					 int error_code, int si_code)
1395{
1396	struct siginfo info;
1397
1398	fill_sigtrap_info(tsk, regs, error_code, si_code, &info);
1399	/* Send us the fake SIGTRAP */
1400	force_sig_info(SIGTRAP, &info, tsk);
1401}
v4.10.11
   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/tracehook.h>
  15#include <linux/user.h>
  16#include <linux/elf.h>
  17#include <linux/security.h>
  18#include <linux/audit.h>
  19#include <linux/seccomp.h>
  20#include <linux/signal.h>
  21#include <linux/perf_event.h>
  22#include <linux/hw_breakpoint.h>
  23#include <linux/rcupdate.h>
  24#include <linux/export.h>
  25#include <linux/context_tracking.h>
  26
  27#include <linux/uaccess.h>
  28#include <asm/pgtable.h>
  29#include <asm/processor.h>
  30#include <asm/fpu/internal.h>
  31#include <asm/fpu/signal.h>
  32#include <asm/fpu/regset.h>
  33#include <asm/debugreg.h>
  34#include <asm/ldt.h>
  35#include <asm/desc.h>
  36#include <asm/prctl.h>
  37#include <asm/proto.h>
  38#include <asm/hw_breakpoint.h>
  39#include <asm/traps.h>
  40#include <asm/syscall.h>
  41
  42#include "tls.h"
  43
  44enum x86_regset {
  45	REGSET_GENERAL,
  46	REGSET_FP,
  47	REGSET_XFP,
  48	REGSET_IOPERM64 = REGSET_XFP,
  49	REGSET_XSTATE,
  50	REGSET_TLS,
  51	REGSET_IOPERM32,
  52};
  53
  54struct pt_regs_offset {
  55	const char *name;
  56	int offset;
  57};
  58
  59#define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
  60#define REG_OFFSET_END {.name = NULL, .offset = 0}
  61
  62static const struct pt_regs_offset regoffset_table[] = {
  63#ifdef CONFIG_X86_64
  64	REG_OFFSET_NAME(r15),
  65	REG_OFFSET_NAME(r14),
  66	REG_OFFSET_NAME(r13),
  67	REG_OFFSET_NAME(r12),
  68	REG_OFFSET_NAME(r11),
  69	REG_OFFSET_NAME(r10),
  70	REG_OFFSET_NAME(r9),
  71	REG_OFFSET_NAME(r8),
  72#endif
  73	REG_OFFSET_NAME(bx),
  74	REG_OFFSET_NAME(cx),
  75	REG_OFFSET_NAME(dx),
  76	REG_OFFSET_NAME(si),
  77	REG_OFFSET_NAME(di),
  78	REG_OFFSET_NAME(bp),
  79	REG_OFFSET_NAME(ax),
  80#ifdef CONFIG_X86_32
  81	REG_OFFSET_NAME(ds),
  82	REG_OFFSET_NAME(es),
  83	REG_OFFSET_NAME(fs),
  84	REG_OFFSET_NAME(gs),
  85#endif
  86	REG_OFFSET_NAME(orig_ax),
  87	REG_OFFSET_NAME(ip),
  88	REG_OFFSET_NAME(cs),
  89	REG_OFFSET_NAME(flags),
  90	REG_OFFSET_NAME(sp),
  91	REG_OFFSET_NAME(ss),
  92	REG_OFFSET_END,
  93};
  94
  95/**
  96 * regs_query_register_offset() - query register offset from its name
  97 * @name:	the name of a register
  98 *
  99 * regs_query_register_offset() returns the offset of a register in struct
 100 * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 101 */
 102int regs_query_register_offset(const char *name)
 103{
 104	const struct pt_regs_offset *roff;
 105	for (roff = regoffset_table; roff->name != NULL; roff++)
 106		if (!strcmp(roff->name, name))
 107			return roff->offset;
 108	return -EINVAL;
 109}
 110
 111/**
 112 * regs_query_register_name() - query register name from its offset
 113 * @offset:	the offset of a register in struct pt_regs.
 114 *
 115 * regs_query_register_name() returns the name of a register from its
 116 * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
 117 */
 118const char *regs_query_register_name(unsigned int offset)
 119{
 120	const struct pt_regs_offset *roff;
 121	for (roff = regoffset_table; roff->name != NULL; roff++)
 122		if (roff->offset == offset)
 123			return roff->name;
 124	return NULL;
 125}
 126
 127/*
 128 * does not yet catch signals sent when the child dies.
 129 * in exit.c or in signal.c.
 130 */
 131
 132/*
 133 * Determines which flags the user has access to [1 = access, 0 = no access].
 134 */
 135#define FLAG_MASK_32		((unsigned long)			\
 136				 (X86_EFLAGS_CF | X86_EFLAGS_PF |	\
 137				  X86_EFLAGS_AF | X86_EFLAGS_ZF |	\
 138				  X86_EFLAGS_SF | X86_EFLAGS_TF |	\
 139				  X86_EFLAGS_DF | X86_EFLAGS_OF |	\
 140				  X86_EFLAGS_RF | X86_EFLAGS_AC))
 141
 142/*
 143 * Determines whether a value may be installed in a segment register.
 144 */
 145static inline bool invalid_selector(u16 value)
 146{
 147	return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
 148}
 149
 150#ifdef CONFIG_X86_32
 151
 152#define FLAG_MASK		FLAG_MASK_32
 153
 154/*
 155 * X86_32 CPUs don't save ss and esp if the CPU is already in kernel mode
 156 * when it traps.  The previous stack will be directly underneath the saved
 157 * registers, and 'sp/ss' won't even have been saved. Thus the '&regs->sp'.
 158 *
 159 * Now, if the stack is empty, '&regs->sp' is out of range. In this
 160 * case we try to take the previous stack. To always return a non-null
 161 * stack pointer we fall back to regs as stack if no previous stack
 162 * exists.
 163 *
 164 * This is valid only for kernel mode traps.
 165 */
 166unsigned long kernel_stack_pointer(struct pt_regs *regs)
 167{
 168	unsigned long context = (unsigned long)regs & ~(THREAD_SIZE - 1);
 169	unsigned long sp = (unsigned long)&regs->sp;
 170	u32 *prev_esp;
 171
 172	if (context == (sp & ~(THREAD_SIZE - 1)))
 173		return sp;
 174
 175	prev_esp = (u32 *)(context);
 176	if (*prev_esp)
 177		return (unsigned long)*prev_esp;
 178
 179	return (unsigned long)regs;
 180}
 181EXPORT_SYMBOL_GPL(kernel_stack_pointer);
 182
 183static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
 184{
 185	BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
 186	return &regs->bx + (regno >> 2);
 187}
 188
 189static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 190{
 191	/*
 192	 * Returning the value truncates it to 16 bits.
 193	 */
 194	unsigned int retval;
 195	if (offset != offsetof(struct user_regs_struct, gs))
 196		retval = *pt_regs_access(task_pt_regs(task), offset);
 197	else {
 198		if (task == current)
 199			retval = get_user_gs(task_pt_regs(task));
 200		else
 201			retval = task_user_gs(task);
 202	}
 203	return retval;
 204}
 205
 206static int set_segment_reg(struct task_struct *task,
 207			   unsigned long offset, u16 value)
 208{
 209	/*
 210	 * The value argument was already truncated to 16 bits.
 211	 */
 212	if (invalid_selector(value))
 213		return -EIO;
 214
 215	/*
 216	 * For %cs and %ss we cannot permit a null selector.
 217	 * We can permit a bogus selector as long as it has USER_RPL.
 218	 * Null selectors are fine for other segment registers, but
 219	 * we will never get back to user mode with invalid %cs or %ss
 220	 * and will take the trap in iret instead.  Much code relies
 221	 * on user_mode() to distinguish a user trap frame (which can
 222	 * safely use invalid selectors) from a kernel trap frame.
 223	 */
 224	switch (offset) {
 225	case offsetof(struct user_regs_struct, cs):
 226	case offsetof(struct user_regs_struct, ss):
 227		if (unlikely(value == 0))
 228			return -EIO;
 229
 230	default:
 231		*pt_regs_access(task_pt_regs(task), offset) = value;
 232		break;
 233
 234	case offsetof(struct user_regs_struct, gs):
 235		if (task == current)
 236			set_user_gs(task_pt_regs(task), value);
 237		else
 238			task_user_gs(task) = value;
 239	}
 240
 241	return 0;
 242}
 243
 244#else  /* CONFIG_X86_64 */
 245
 246#define FLAG_MASK		(FLAG_MASK_32 | X86_EFLAGS_NT)
 247
 248static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
 249{
 250	BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
 251	return &regs->r15 + (offset / sizeof(regs->r15));
 252}
 253
 254static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 255{
 256	/*
 257	 * Returning the value truncates it to 16 bits.
 258	 */
 259	unsigned int seg;
 260
 261	switch (offset) {
 262	case offsetof(struct user_regs_struct, fs):
 263		if (task == current) {
 264			/* Older gas can't assemble movq %?s,%r?? */
 265			asm("movl %%fs,%0" : "=r" (seg));
 266			return seg;
 267		}
 268		return task->thread.fsindex;
 269	case offsetof(struct user_regs_struct, gs):
 270		if (task == current) {
 271			asm("movl %%gs,%0" : "=r" (seg));
 272			return seg;
 273		}
 274		return task->thread.gsindex;
 275	case offsetof(struct user_regs_struct, ds):
 276		if (task == current) {
 277			asm("movl %%ds,%0" : "=r" (seg));
 278			return seg;
 279		}
 280		return task->thread.ds;
 281	case offsetof(struct user_regs_struct, es):
 282		if (task == current) {
 283			asm("movl %%es,%0" : "=r" (seg));
 284			return seg;
 285		}
 286		return task->thread.es;
 287
 288	case offsetof(struct user_regs_struct, cs):
 289	case offsetof(struct user_regs_struct, ss):
 290		break;
 291	}
 292	return *pt_regs_access(task_pt_regs(task), offset);
 293}
 294
 295static int set_segment_reg(struct task_struct *task,
 296			   unsigned long offset, u16 value)
 297{
 298	/*
 299	 * The value argument was already truncated to 16 bits.
 300	 */
 301	if (invalid_selector(value))
 302		return -EIO;
 303
 304	switch (offset) {
 305	case offsetof(struct user_regs_struct,fs):
 306		task->thread.fsindex = value;
 307		if (task == current)
 308			loadsegment(fs, task->thread.fsindex);
 309		break;
 310	case offsetof(struct user_regs_struct,gs):
 311		task->thread.gsindex = value;
 312		if (task == current)
 313			load_gs_index(task->thread.gsindex);
 314		break;
 315	case offsetof(struct user_regs_struct,ds):
 316		task->thread.ds = value;
 317		if (task == current)
 318			loadsegment(ds, task->thread.ds);
 319		break;
 320	case offsetof(struct user_regs_struct,es):
 321		task->thread.es = value;
 322		if (task == current)
 323			loadsegment(es, task->thread.es);
 324		break;
 325
 326		/*
 327		 * Can't actually change these in 64-bit mode.
 328		 */
 329	case offsetof(struct user_regs_struct,cs):
 330		if (unlikely(value == 0))
 331			return -EIO;
 332		task_pt_regs(task)->cs = value;
 333		break;
 334	case offsetof(struct user_regs_struct,ss):
 335		if (unlikely(value == 0))
 336			return -EIO;
 337		task_pt_regs(task)->ss = value;
 338		break;
 339	}
 340
 341	return 0;
 342}
 343
 344#endif	/* CONFIG_X86_32 */
 345
 346static unsigned long get_flags(struct task_struct *task)
 347{
 348	unsigned long retval = task_pt_regs(task)->flags;
 349
 350	/*
 351	 * If the debugger set TF, hide it from the readout.
 352	 */
 353	if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 354		retval &= ~X86_EFLAGS_TF;
 355
 356	return retval;
 357}
 358
 359static int set_flags(struct task_struct *task, unsigned long value)
 360{
 361	struct pt_regs *regs = task_pt_regs(task);
 362
 363	/*
 364	 * If the user value contains TF, mark that
 365	 * it was not "us" (the debugger) that set it.
 366	 * If not, make sure it stays set if we had.
 367	 */
 368	if (value & X86_EFLAGS_TF)
 369		clear_tsk_thread_flag(task, TIF_FORCED_TF);
 370	else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 371		value |= X86_EFLAGS_TF;
 372
 373	regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
 374
 375	return 0;
 376}
 377
 378static int putreg(struct task_struct *child,
 379		  unsigned long offset, unsigned long value)
 380{
 381	switch (offset) {
 382	case offsetof(struct user_regs_struct, cs):
 383	case offsetof(struct user_regs_struct, ds):
 384	case offsetof(struct user_regs_struct, es):
 385	case offsetof(struct user_regs_struct, fs):
 386	case offsetof(struct user_regs_struct, gs):
 387	case offsetof(struct user_regs_struct, ss):
 388		return set_segment_reg(child, offset, value);
 389
 390	case offsetof(struct user_regs_struct, flags):
 391		return set_flags(child, value);
 392
 393#ifdef CONFIG_X86_64
 394	case offsetof(struct user_regs_struct,fs_base):
 395		if (value >= TASK_SIZE_MAX)
 396			return -EIO;
 397		/*
 398		 * When changing the segment base, use do_arch_prctl
 399		 * to set either thread.fs or thread.fsindex and the
 400		 * corresponding GDT slot.
 401		 */
 402		if (child->thread.fsbase != value)
 403			return do_arch_prctl(child, ARCH_SET_FS, value);
 404		return 0;
 405	case offsetof(struct user_regs_struct,gs_base):
 406		/*
 407		 * Exactly the same here as the %fs handling above.
 408		 */
 409		if (value >= TASK_SIZE_MAX)
 410			return -EIO;
 411		if (child->thread.gsbase != value)
 412			return do_arch_prctl(child, ARCH_SET_GS, value);
 413		return 0;
 414#endif
 415	}
 416
 417	*pt_regs_access(task_pt_regs(child), offset) = value;
 418	return 0;
 419}
 420
 421static unsigned long getreg(struct task_struct *task, unsigned long offset)
 422{
 423	switch (offset) {
 424	case offsetof(struct user_regs_struct, cs):
 425	case offsetof(struct user_regs_struct, ds):
 426	case offsetof(struct user_regs_struct, es):
 427	case offsetof(struct user_regs_struct, fs):
 428	case offsetof(struct user_regs_struct, gs):
 429	case offsetof(struct user_regs_struct, ss):
 430		return get_segment_reg(task, offset);
 431
 432	case offsetof(struct user_regs_struct, flags):
 433		return get_flags(task);
 434
 435#ifdef CONFIG_X86_64
 436	case offsetof(struct user_regs_struct, fs_base): {
 437		/*
 438		 * XXX: This will not behave as expected if called on
 439		 * current or if fsindex != 0.
 440		 */
 441		return task->thread.fsbase;
 442	}
 443	case offsetof(struct user_regs_struct, gs_base): {
 444		/*
 445		 * XXX: This will not behave as expected if called on
 446		 * current or if fsindex != 0.
 447		 */
 448		return task->thread.gsbase;
 449	}
 450#endif
 451	}
 452
 453	return *pt_regs_access(task_pt_regs(task), offset);
 454}
 455
 456static int genregs_get(struct task_struct *target,
 457		       const struct user_regset *regset,
 458		       unsigned int pos, unsigned int count,
 459		       void *kbuf, void __user *ubuf)
 460{
 461	if (kbuf) {
 462		unsigned long *k = kbuf;
 463		while (count >= sizeof(*k)) {
 464			*k++ = getreg(target, pos);
 465			count -= sizeof(*k);
 466			pos += sizeof(*k);
 467		}
 468	} else {
 469		unsigned long __user *u = ubuf;
 470		while (count >= sizeof(*u)) {
 471			if (__put_user(getreg(target, pos), u++))
 472				return -EFAULT;
 473			count -= sizeof(*u);
 474			pos += sizeof(*u);
 475		}
 476	}
 477
 478	return 0;
 479}
 480
 481static int genregs_set(struct task_struct *target,
 482		       const struct user_regset *regset,
 483		       unsigned int pos, unsigned int count,
 484		       const void *kbuf, const void __user *ubuf)
 485{
 486	int ret = 0;
 487	if (kbuf) {
 488		const unsigned long *k = kbuf;
 489		while (count >= sizeof(*k) && !ret) {
 490			ret = putreg(target, pos, *k++);
 491			count -= sizeof(*k);
 492			pos += sizeof(*k);
 493		}
 494	} else {
 495		const unsigned long  __user *u = ubuf;
 496		while (count >= sizeof(*u) && !ret) {
 497			unsigned long word;
 498			ret = __get_user(word, u++);
 499			if (ret)
 500				break;
 501			ret = putreg(target, pos, word);
 502			count -= sizeof(*u);
 503			pos += sizeof(*u);
 504		}
 505	}
 506	return ret;
 507}
 508
 509static void ptrace_triggered(struct perf_event *bp,
 510			     struct perf_sample_data *data,
 511			     struct pt_regs *regs)
 512{
 513	int i;
 514	struct thread_struct *thread = &(current->thread);
 515
 516	/*
 517	 * Store in the virtual DR6 register the fact that the breakpoint
 518	 * was hit so the thread's debugger will see it.
 519	 */
 520	for (i = 0; i < HBP_NUM; i++) {
 521		if (thread->ptrace_bps[i] == bp)
 522			break;
 523	}
 524
 525	thread->debugreg6 |= (DR_TRAP0 << i);
 526}
 527
 528/*
 529 * Walk through every ptrace breakpoints for this thread and
 530 * build the dr7 value on top of their attributes.
 531 *
 532 */
 533static unsigned long ptrace_get_dr7(struct perf_event *bp[])
 534{
 535	int i;
 536	int dr7 = 0;
 537	struct arch_hw_breakpoint *info;
 538
 539	for (i = 0; i < HBP_NUM; i++) {
 540		if (bp[i] && !bp[i]->attr.disabled) {
 541			info = counter_arch_bp(bp[i]);
 542			dr7 |= encode_dr7(i, info->len, info->type);
 543		}
 544	}
 545
 546	return dr7;
 547}
 548
 549static int ptrace_fill_bp_fields(struct perf_event_attr *attr,
 550					int len, int type, bool disabled)
 551{
 552	int err, bp_len, bp_type;
 553
 554	err = arch_bp_generic_fields(len, type, &bp_len, &bp_type);
 555	if (!err) {
 556		attr->bp_len = bp_len;
 557		attr->bp_type = bp_type;
 558		attr->disabled = disabled;
 559	}
 560
 561	return err;
 562}
 563
 564static struct perf_event *
 565ptrace_register_breakpoint(struct task_struct *tsk, int len, int type,
 566				unsigned long addr, bool disabled)
 567{
 568	struct perf_event_attr attr;
 569	int err;
 570
 571	ptrace_breakpoint_init(&attr);
 572	attr.bp_addr = addr;
 573
 574	err = ptrace_fill_bp_fields(&attr, len, type, disabled);
 575	if (err)
 576		return ERR_PTR(err);
 577
 578	return register_user_hw_breakpoint(&attr, ptrace_triggered,
 579						 NULL, tsk);
 580}
 581
 582static int ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
 583					int disabled)
 584{
 585	struct perf_event_attr attr = bp->attr;
 586	int err;
 587
 588	err = ptrace_fill_bp_fields(&attr, len, type, disabled);
 589	if (err)
 590		return err;
 591
 592	return modify_user_hw_breakpoint(bp, &attr);
 593}
 594
 595/*
 596 * Handle ptrace writes to debug register 7.
 597 */
 598static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
 599{
 600	struct thread_struct *thread = &tsk->thread;
 601	unsigned long old_dr7;
 602	bool second_pass = false;
 603	int i, rc, ret = 0;
 604
 605	data &= ~DR_CONTROL_RESERVED;
 606	old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
 607
 608restore:
 609	rc = 0;
 610	for (i = 0; i < HBP_NUM; i++) {
 611		unsigned len, type;
 612		bool disabled = !decode_dr7(data, i, &len, &type);
 613		struct perf_event *bp = thread->ptrace_bps[i];
 614
 615		if (!bp) {
 616			if (disabled)
 617				continue;
 618
 619			bp = ptrace_register_breakpoint(tsk,
 620					len, type, 0, disabled);
 621			if (IS_ERR(bp)) {
 622				rc = PTR_ERR(bp);
 623				break;
 624			}
 625
 626			thread->ptrace_bps[i] = bp;
 627			continue;
 628		}
 629
 630		rc = ptrace_modify_breakpoint(bp, len, type, disabled);
 631		if (rc)
 632			break;
 633	}
 634
 635	/* Restore if the first pass failed, second_pass shouldn't fail. */
 636	if (rc && !WARN_ON(second_pass)) {
 637		ret = rc;
 638		data = old_dr7;
 639		second_pass = true;
 640		goto restore;
 641	}
 642
 643	return ret;
 644}
 645
 646/*
 647 * Handle PTRACE_PEEKUSR calls for the debug register area.
 648 */
 649static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
 650{
 651	struct thread_struct *thread = &tsk->thread;
 652	unsigned long val = 0;
 653
 654	if (n < HBP_NUM) {
 655		struct perf_event *bp = thread->ptrace_bps[n];
 656
 657		if (bp)
 658			val = bp->hw.info.address;
 659	} else if (n == 6) {
 660		val = thread->debugreg6;
 661	} else if (n == 7) {
 662		val = thread->ptrace_dr7;
 663	}
 664	return val;
 665}
 666
 667static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
 668				      unsigned long addr)
 669{
 670	struct thread_struct *t = &tsk->thread;
 671	struct perf_event *bp = t->ptrace_bps[nr];
 672	int err = 0;
 673
 674	if (!bp) {
 675		/*
 676		 * Put stub len and type to create an inactive but correct bp.
 677		 *
 678		 * CHECKME: the previous code returned -EIO if the addr wasn't
 679		 * a valid task virtual addr. The new one will return -EINVAL in
 680		 *  this case.
 681		 * -EINVAL may be what we want for in-kernel breakpoints users,
 682		 * but -EIO looks better for ptrace, since we refuse a register
 683		 * writing for the user. And anyway this is the previous
 684		 * behaviour.
 685		 */
 686		bp = ptrace_register_breakpoint(tsk,
 687				X86_BREAKPOINT_LEN_1, X86_BREAKPOINT_WRITE,
 688				addr, true);
 689		if (IS_ERR(bp))
 690			err = PTR_ERR(bp);
 691		else
 692			t->ptrace_bps[nr] = bp;
 693	} else {
 694		struct perf_event_attr attr = bp->attr;
 695
 696		attr.bp_addr = addr;
 697		err = modify_user_hw_breakpoint(bp, &attr);
 698	}
 699
 700	return err;
 701}
 702
 703/*
 704 * Handle PTRACE_POKEUSR calls for the debug register area.
 705 */
 706static int ptrace_set_debugreg(struct task_struct *tsk, int n,
 707			       unsigned long val)
 708{
 709	struct thread_struct *thread = &tsk->thread;
 710	/* There are no DR4 or DR5 registers */
 711	int rc = -EIO;
 712
 713	if (n < HBP_NUM) {
 714		rc = ptrace_set_breakpoint_addr(tsk, n, val);
 715	} else if (n == 6) {
 716		thread->debugreg6 = val;
 717		rc = 0;
 718	} else if (n == 7) {
 719		rc = ptrace_write_dr7(tsk, val);
 720		if (!rc)
 721			thread->ptrace_dr7 = val;
 722	}
 723	return rc;
 724}
 725
 726/*
 727 * These access the current or another (stopped) task's io permission
 728 * bitmap for debugging or core dump.
 729 */
 730static int ioperm_active(struct task_struct *target,
 731			 const struct user_regset *regset)
 732{
 733	return target->thread.io_bitmap_max / regset->size;
 734}
 735
 736static int ioperm_get(struct task_struct *target,
 737		      const struct user_regset *regset,
 738		      unsigned int pos, unsigned int count,
 739		      void *kbuf, void __user *ubuf)
 740{
 741	if (!target->thread.io_bitmap_ptr)
 742		return -ENXIO;
 743
 744	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 745				   target->thread.io_bitmap_ptr,
 746				   0, IO_BITMAP_BYTES);
 747}
 748
 749/*
 750 * Called by kernel/ptrace.c when detaching..
 751 *
 752 * Make sure the single step bit is not set.
 753 */
 754void ptrace_disable(struct task_struct *child)
 755{
 756	user_disable_single_step(child);
 757#ifdef TIF_SYSCALL_EMU
 758	clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
 759#endif
 760}
 761
 762#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 763static const struct user_regset_view user_x86_32_view; /* Initialized below. */
 764#endif
 765
 766long arch_ptrace(struct task_struct *child, long request,
 767		 unsigned long addr, unsigned long data)
 768{
 769	int ret;
 770	unsigned long __user *datap = (unsigned long __user *)data;
 771
 772	switch (request) {
 773	/* read the word at location addr in the USER area. */
 774	case PTRACE_PEEKUSR: {
 775		unsigned long tmp;
 776
 777		ret = -EIO;
 778		if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 779			break;
 780
 781		tmp = 0;  /* Default return condition */
 782		if (addr < sizeof(struct user_regs_struct))
 783			tmp = getreg(child, addr);
 784		else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 785			 addr <= offsetof(struct user, u_debugreg[7])) {
 786			addr -= offsetof(struct user, u_debugreg[0]);
 787			tmp = ptrace_get_debugreg(child, addr / sizeof(data));
 788		}
 789		ret = put_user(tmp, datap);
 790		break;
 791	}
 792
 793	case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
 794		ret = -EIO;
 795		if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 796			break;
 797
 798		if (addr < sizeof(struct user_regs_struct))
 799			ret = putreg(child, addr, data);
 800		else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 801			 addr <= offsetof(struct user, u_debugreg[7])) {
 802			addr -= offsetof(struct user, u_debugreg[0]);
 803			ret = ptrace_set_debugreg(child,
 804						  addr / sizeof(data), data);
 805		}
 806		break;
 807
 808	case PTRACE_GETREGS:	/* Get all gp regs from the child. */
 809		return copy_regset_to_user(child,
 810					   task_user_regset_view(current),
 811					   REGSET_GENERAL,
 812					   0, sizeof(struct user_regs_struct),
 813					   datap);
 814
 815	case PTRACE_SETREGS:	/* Set all gp regs in the child. */
 816		return copy_regset_from_user(child,
 817					     task_user_regset_view(current),
 818					     REGSET_GENERAL,
 819					     0, sizeof(struct user_regs_struct),
 820					     datap);
 821
 822	case PTRACE_GETFPREGS:	/* Get the child FPU state. */
 823		return copy_regset_to_user(child,
 824					   task_user_regset_view(current),
 825					   REGSET_FP,
 826					   0, sizeof(struct user_i387_struct),
 827					   datap);
 828
 829	case PTRACE_SETFPREGS:	/* Set the child FPU state. */
 830		return copy_regset_from_user(child,
 831					     task_user_regset_view(current),
 832					     REGSET_FP,
 833					     0, sizeof(struct user_i387_struct),
 834					     datap);
 835
 836#ifdef CONFIG_X86_32
 837	case PTRACE_GETFPXREGS:	/* Get the child extended FPU state. */
 838		return copy_regset_to_user(child, &user_x86_32_view,
 839					   REGSET_XFP,
 840					   0, sizeof(struct user_fxsr_struct),
 841					   datap) ? -EIO : 0;
 842
 843	case PTRACE_SETFPXREGS:	/* Set the child extended FPU state. */
 844		return copy_regset_from_user(child, &user_x86_32_view,
 845					     REGSET_XFP,
 846					     0, sizeof(struct user_fxsr_struct),
 847					     datap) ? -EIO : 0;
 848#endif
 849
 850#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 851	case PTRACE_GET_THREAD_AREA:
 852		if ((int) addr < 0)
 853			return -EIO;
 854		ret = do_get_thread_area(child, addr,
 855					(struct user_desc __user *)data);
 856		break;
 857
 858	case PTRACE_SET_THREAD_AREA:
 859		if ((int) addr < 0)
 860			return -EIO;
 861		ret = do_set_thread_area(child, addr,
 862					(struct user_desc __user *)data, 0);
 863		break;
 864#endif
 865
 866#ifdef CONFIG_X86_64
 867		/* normal 64bit interface to access TLS data.
 868		   Works just like arch_prctl, except that the arguments
 869		   are reversed. */
 870	case PTRACE_ARCH_PRCTL:
 871		ret = do_arch_prctl(child, data, addr);
 872		break;
 873#endif
 874
 875	default:
 876		ret = ptrace_request(child, request, addr, data);
 877		break;
 878	}
 879
 880	return ret;
 881}
 882
 883#ifdef CONFIG_IA32_EMULATION
 884
 885#include <linux/compat.h>
 886#include <linux/syscalls.h>
 887#include <asm/ia32.h>
 888#include <asm/user32.h>
 889
 890#define R32(l,q)							\
 891	case offsetof(struct user32, regs.l):				\
 892		regs->q = value; break
 893
 894#define SEG32(rs)							\
 895	case offsetof(struct user32, regs.rs):				\
 896		return set_segment_reg(child,				\
 897				       offsetof(struct user_regs_struct, rs), \
 898				       value);				\
 899		break
 900
 901static int putreg32(struct task_struct *child, unsigned regno, u32 value)
 902{
 903	struct pt_regs *regs = task_pt_regs(child);
 904
 905	switch (regno) {
 906
 907	SEG32(cs);
 908	SEG32(ds);
 909	SEG32(es);
 910	SEG32(fs);
 911	SEG32(gs);
 912	SEG32(ss);
 913
 914	R32(ebx, bx);
 915	R32(ecx, cx);
 916	R32(edx, dx);
 917	R32(edi, di);
 918	R32(esi, si);
 919	R32(ebp, bp);
 920	R32(eax, ax);
 921	R32(eip, ip);
 922	R32(esp, sp);
 923
 924	case offsetof(struct user32, regs.orig_eax):
 925		/*
 926		 * Warning: bizarre corner case fixup here.  A 32-bit
 927		 * debugger setting orig_eax to -1 wants to disable
 928		 * syscall restart.  Make sure that the syscall
 929		 * restart code sign-extends orig_ax.  Also make sure
 930		 * we interpret the -ERESTART* codes correctly if
 931		 * loaded into regs->ax in case the task is not
 932		 * actually still sitting at the exit from a 32-bit
 933		 * syscall with TS_COMPAT still set.
 934		 */
 935		regs->orig_ax = value;
 936		if (syscall_get_nr(child, regs) >= 0)
 937			child->thread.status |= TS_I386_REGS_POKED;
 938		break;
 939
 940	case offsetof(struct user32, regs.eflags):
 941		return set_flags(child, value);
 942
 943	case offsetof(struct user32, u_debugreg[0]) ...
 944		offsetof(struct user32, u_debugreg[7]):
 945		regno -= offsetof(struct user32, u_debugreg[0]);
 946		return ptrace_set_debugreg(child, regno / 4, value);
 947
 948	default:
 949		if (regno > sizeof(struct user32) || (regno & 3))
 950			return -EIO;
 951
 952		/*
 953		 * Other dummy fields in the virtual user structure
 954		 * are ignored
 955		 */
 956		break;
 957	}
 958	return 0;
 959}
 960
 961#undef R32
 962#undef SEG32
 963
 964#define R32(l,q)							\
 965	case offsetof(struct user32, regs.l):				\
 966		*val = regs->q; break
 967
 968#define SEG32(rs)							\
 969	case offsetof(struct user32, regs.rs):				\
 970		*val = get_segment_reg(child,				\
 971				       offsetof(struct user_regs_struct, rs)); \
 972		break
 973
 974static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
 975{
 976	struct pt_regs *regs = task_pt_regs(child);
 977
 978	switch (regno) {
 979
 980	SEG32(ds);
 981	SEG32(es);
 982	SEG32(fs);
 983	SEG32(gs);
 984
 985	R32(cs, cs);
 986	R32(ss, ss);
 987	R32(ebx, bx);
 988	R32(ecx, cx);
 989	R32(edx, dx);
 990	R32(edi, di);
 991	R32(esi, si);
 992	R32(ebp, bp);
 993	R32(eax, ax);
 994	R32(orig_eax, orig_ax);
 995	R32(eip, ip);
 996	R32(esp, sp);
 997
 998	case offsetof(struct user32, regs.eflags):
 999		*val = get_flags(child);
1000		break;
1001
1002	case offsetof(struct user32, u_debugreg[0]) ...
1003		offsetof(struct user32, u_debugreg[7]):
1004		regno -= offsetof(struct user32, u_debugreg[0]);
1005		*val = ptrace_get_debugreg(child, regno / 4);
1006		break;
1007
1008	default:
1009		if (regno > sizeof(struct user32) || (regno & 3))
1010			return -EIO;
1011
1012		/*
1013		 * Other dummy fields in the virtual user structure
1014		 * are ignored
1015		 */
1016		*val = 0;
1017		break;
1018	}
1019	return 0;
1020}
1021
1022#undef R32
1023#undef SEG32
1024
1025static int genregs32_get(struct task_struct *target,
1026			 const struct user_regset *regset,
1027			 unsigned int pos, unsigned int count,
1028			 void *kbuf, void __user *ubuf)
1029{
1030	if (kbuf) {
1031		compat_ulong_t *k = kbuf;
1032		while (count >= sizeof(*k)) {
1033			getreg32(target, pos, k++);
1034			count -= sizeof(*k);
1035			pos += sizeof(*k);
1036		}
1037	} else {
1038		compat_ulong_t __user *u = ubuf;
1039		while (count >= sizeof(*u)) {
1040			compat_ulong_t word;
1041			getreg32(target, pos, &word);
1042			if (__put_user(word, u++))
1043				return -EFAULT;
1044			count -= sizeof(*u);
1045			pos += sizeof(*u);
1046		}
1047	}
1048
1049	return 0;
1050}
1051
1052static int genregs32_set(struct task_struct *target,
1053			 const struct user_regset *regset,
1054			 unsigned int pos, unsigned int count,
1055			 const void *kbuf, const void __user *ubuf)
1056{
1057	int ret = 0;
1058	if (kbuf) {
1059		const compat_ulong_t *k = kbuf;
1060		while (count >= sizeof(*k) && !ret) {
1061			ret = putreg32(target, pos, *k++);
1062			count -= sizeof(*k);
1063			pos += sizeof(*k);
1064		}
1065	} else {
1066		const compat_ulong_t __user *u = ubuf;
1067		while (count >= sizeof(*u) && !ret) {
1068			compat_ulong_t word;
1069			ret = __get_user(word, u++);
1070			if (ret)
1071				break;
1072			ret = putreg32(target, pos, word);
1073			count -= sizeof(*u);
1074			pos += sizeof(*u);
1075		}
1076	}
1077	return ret;
1078}
1079
1080static long ia32_arch_ptrace(struct task_struct *child, compat_long_t request,
1081			     compat_ulong_t caddr, compat_ulong_t cdata)
1082{
1083	unsigned long addr = caddr;
1084	unsigned long data = cdata;
1085	void __user *datap = compat_ptr(data);
1086	int ret;
1087	__u32 val;
1088
1089	switch (request) {
1090	case PTRACE_PEEKUSR:
1091		ret = getreg32(child, addr, &val);
1092		if (ret == 0)
1093			ret = put_user(val, (__u32 __user *)datap);
1094		break;
1095
1096	case PTRACE_POKEUSR:
1097		ret = putreg32(child, addr, data);
1098		break;
1099
1100	case PTRACE_GETREGS:	/* Get all gp regs from the child. */
1101		return copy_regset_to_user(child, &user_x86_32_view,
1102					   REGSET_GENERAL,
1103					   0, sizeof(struct user_regs_struct32),
1104					   datap);
1105
1106	case PTRACE_SETREGS:	/* Set all gp regs in the child. */
1107		return copy_regset_from_user(child, &user_x86_32_view,
1108					     REGSET_GENERAL, 0,
1109					     sizeof(struct user_regs_struct32),
1110					     datap);
1111
1112	case PTRACE_GETFPREGS:	/* Get the child FPU state. */
1113		return copy_regset_to_user(child, &user_x86_32_view,
1114					   REGSET_FP, 0,
1115					   sizeof(struct user_i387_ia32_struct),
1116					   datap);
1117
1118	case PTRACE_SETFPREGS:	/* Set the child FPU state. */
1119		return copy_regset_from_user(
1120			child, &user_x86_32_view, REGSET_FP,
1121			0, sizeof(struct user_i387_ia32_struct), datap);
1122
1123	case PTRACE_GETFPXREGS:	/* Get the child extended FPU state. */
1124		return copy_regset_to_user(child, &user_x86_32_view,
1125					   REGSET_XFP, 0,
1126					   sizeof(struct user32_fxsr_struct),
1127					   datap);
1128
1129	case PTRACE_SETFPXREGS:	/* Set the child extended FPU state. */
1130		return copy_regset_from_user(child, &user_x86_32_view,
1131					     REGSET_XFP, 0,
1132					     sizeof(struct user32_fxsr_struct),
1133					     datap);
1134
1135	case PTRACE_GET_THREAD_AREA:
1136	case PTRACE_SET_THREAD_AREA:
1137		return arch_ptrace(child, request, addr, data);
1138
1139	default:
1140		return compat_ptrace_request(child, request, addr, data);
1141	}
1142
1143	return ret;
1144}
1145#endif /* CONFIG_IA32_EMULATION */
1146
1147#ifdef CONFIG_X86_X32_ABI
1148static long x32_arch_ptrace(struct task_struct *child,
1149			    compat_long_t request, compat_ulong_t caddr,
1150			    compat_ulong_t cdata)
1151{
1152	unsigned long addr = caddr;
1153	unsigned long data = cdata;
1154	void __user *datap = compat_ptr(data);
1155	int ret;
1156
1157	switch (request) {
1158	/* Read 32bits at location addr in the USER area.  Only allow
1159	   to return the lower 32bits of segment and debug registers.  */
1160	case PTRACE_PEEKUSR: {
1161		u32 tmp;
1162
1163		ret = -EIO;
1164		if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1165		    addr < offsetof(struct user_regs_struct, cs))
1166			break;
1167
1168		tmp = 0;  /* Default return condition */
1169		if (addr < sizeof(struct user_regs_struct))
1170			tmp = getreg(child, addr);
1171		else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1172			 addr <= offsetof(struct user, u_debugreg[7])) {
1173			addr -= offsetof(struct user, u_debugreg[0]);
1174			tmp = ptrace_get_debugreg(child, addr / sizeof(data));
1175		}
1176		ret = put_user(tmp, (__u32 __user *)datap);
1177		break;
1178	}
1179
1180	/* Write the word at location addr in the USER area.  Only allow
1181	   to update segment and debug registers with the upper 32bits
1182	   zero-extended. */
1183	case PTRACE_POKEUSR:
1184		ret = -EIO;
1185		if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1186		    addr < offsetof(struct user_regs_struct, cs))
1187			break;
1188
1189		if (addr < sizeof(struct user_regs_struct))
1190			ret = putreg(child, addr, data);
1191		else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1192			 addr <= offsetof(struct user, u_debugreg[7])) {
1193			addr -= offsetof(struct user, u_debugreg[0]);
1194			ret = ptrace_set_debugreg(child,
1195						  addr / sizeof(data), data);
1196		}
1197		break;
1198
1199	case PTRACE_GETREGS:	/* Get all gp regs from the child. */
1200		return copy_regset_to_user(child,
1201					   task_user_regset_view(current),
1202					   REGSET_GENERAL,
1203					   0, sizeof(struct user_regs_struct),
1204					   datap);
1205
1206	case PTRACE_SETREGS:	/* Set all gp regs in the child. */
1207		return copy_regset_from_user(child,
1208					     task_user_regset_view(current),
1209					     REGSET_GENERAL,
1210					     0, sizeof(struct user_regs_struct),
1211					     datap);
1212
1213	case PTRACE_GETFPREGS:	/* Get the child FPU state. */
1214		return copy_regset_to_user(child,
1215					   task_user_regset_view(current),
1216					   REGSET_FP,
1217					   0, sizeof(struct user_i387_struct),
1218					   datap);
1219
1220	case PTRACE_SETFPREGS:	/* Set the child FPU state. */
1221		return copy_regset_from_user(child,
1222					     task_user_regset_view(current),
1223					     REGSET_FP,
1224					     0, sizeof(struct user_i387_struct),
1225					     datap);
1226
1227	default:
1228		return compat_ptrace_request(child, request, addr, data);
1229	}
1230
1231	return ret;
1232}
1233#endif
1234
1235#ifdef CONFIG_COMPAT
1236long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1237			compat_ulong_t caddr, compat_ulong_t cdata)
1238{
1239#ifdef CONFIG_X86_X32_ABI
1240	if (!in_ia32_syscall())
1241		return x32_arch_ptrace(child, request, caddr, cdata);
1242#endif
1243#ifdef CONFIG_IA32_EMULATION
1244	return ia32_arch_ptrace(child, request, caddr, cdata);
1245#else
1246	return 0;
1247#endif
1248}
1249#endif	/* CONFIG_COMPAT */
1250
1251#ifdef CONFIG_X86_64
1252
1253static struct user_regset x86_64_regsets[] __ro_after_init = {
1254	[REGSET_GENERAL] = {
1255		.core_note_type = NT_PRSTATUS,
1256		.n = sizeof(struct user_regs_struct) / sizeof(long),
1257		.size = sizeof(long), .align = sizeof(long),
1258		.get = genregs_get, .set = genregs_set
1259	},
1260	[REGSET_FP] = {
1261		.core_note_type = NT_PRFPREG,
1262		.n = sizeof(struct user_i387_struct) / sizeof(long),
1263		.size = sizeof(long), .align = sizeof(long),
1264		.active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1265	},
1266	[REGSET_XSTATE] = {
1267		.core_note_type = NT_X86_XSTATE,
1268		.size = sizeof(u64), .align = sizeof(u64),
1269		.active = xstateregs_active, .get = xstateregs_get,
1270		.set = xstateregs_set
1271	},
1272	[REGSET_IOPERM64] = {
1273		.core_note_type = NT_386_IOPERM,
1274		.n = IO_BITMAP_LONGS,
1275		.size = sizeof(long), .align = sizeof(long),
1276		.active = ioperm_active, .get = ioperm_get
1277	},
1278};
1279
1280static const struct user_regset_view user_x86_64_view = {
1281	.name = "x86_64", .e_machine = EM_X86_64,
1282	.regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1283};
1284
1285#else  /* CONFIG_X86_32 */
1286
1287#define user_regs_struct32	user_regs_struct
1288#define genregs32_get		genregs_get
1289#define genregs32_set		genregs_set
1290
1291#endif	/* CONFIG_X86_64 */
1292
1293#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1294static struct user_regset x86_32_regsets[] __ro_after_init = {
1295	[REGSET_GENERAL] = {
1296		.core_note_type = NT_PRSTATUS,
1297		.n = sizeof(struct user_regs_struct32) / sizeof(u32),
1298		.size = sizeof(u32), .align = sizeof(u32),
1299		.get = genregs32_get, .set = genregs32_set
1300	},
1301	[REGSET_FP] = {
1302		.core_note_type = NT_PRFPREG,
1303		.n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1304		.size = sizeof(u32), .align = sizeof(u32),
1305		.active = regset_fpregs_active, .get = fpregs_get, .set = fpregs_set
1306	},
1307	[REGSET_XFP] = {
1308		.core_note_type = NT_PRXFPREG,
1309		.n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1310		.size = sizeof(u32), .align = sizeof(u32),
1311		.active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1312	},
1313	[REGSET_XSTATE] = {
1314		.core_note_type = NT_X86_XSTATE,
1315		.size = sizeof(u64), .align = sizeof(u64),
1316		.active = xstateregs_active, .get = xstateregs_get,
1317		.set = xstateregs_set
1318	},
1319	[REGSET_TLS] = {
1320		.core_note_type = NT_386_TLS,
1321		.n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1322		.size = sizeof(struct user_desc),
1323		.align = sizeof(struct user_desc),
1324		.active = regset_tls_active,
1325		.get = regset_tls_get, .set = regset_tls_set
1326	},
1327	[REGSET_IOPERM32] = {
1328		.core_note_type = NT_386_IOPERM,
1329		.n = IO_BITMAP_BYTES / sizeof(u32),
1330		.size = sizeof(u32), .align = sizeof(u32),
1331		.active = ioperm_active, .get = ioperm_get
1332	},
1333};
1334
1335static const struct user_regset_view user_x86_32_view = {
1336	.name = "i386", .e_machine = EM_386,
1337	.regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1338};
1339#endif
1340
1341/*
1342 * This represents bytes 464..511 in the memory layout exported through
1343 * the REGSET_XSTATE interface.
1344 */
1345u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1346
1347void __init update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1348{
1349#ifdef CONFIG_X86_64
1350	x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1351#endif
1352#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1353	x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1354#endif
1355	xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1356}
1357
1358const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1359{
1360#ifdef CONFIG_IA32_EMULATION
1361	if (!user_64bit_mode(task_pt_regs(task)))
1362#endif
1363#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1364		return &user_x86_32_view;
1365#endif
1366#ifdef CONFIG_X86_64
1367	return &user_x86_64_view;
1368#endif
1369}
1370
1371static void fill_sigtrap_info(struct task_struct *tsk,
1372				struct pt_regs *regs,
1373				int error_code, int si_code,
1374				struct siginfo *info)
1375{
1376	tsk->thread.trap_nr = X86_TRAP_DB;
1377	tsk->thread.error_code = error_code;
1378
1379	memset(info, 0, sizeof(*info));
1380	info->si_signo = SIGTRAP;
1381	info->si_code = si_code;
1382	info->si_addr = user_mode(regs) ? (void __user *)regs->ip : NULL;
1383}
1384
1385void user_single_step_siginfo(struct task_struct *tsk,
1386				struct pt_regs *regs,
1387				struct siginfo *info)
1388{
1389	fill_sigtrap_info(tsk, regs, 0, TRAP_BRKPT, info);
1390}
1391
1392void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
1393					 int error_code, int si_code)
1394{
1395	struct siginfo info;
1396
1397	fill_sigtrap_info(tsk, regs, error_code, si_code, &info);
1398	/* Send us the fake SIGTRAP */
1399	force_sig_info(SIGTRAP, &info, tsk);
1400}