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}