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v5.4
   1// SPDX-License-Identifier: GPL-2.0-only
   2/* By Ross Biro 1/23/92 */
   3/*
   4 * Pentium III FXSR, SSE support
   5 *	Gareth Hughes <gareth@valinux.com>, May 2000
   6 */
   7
   8#include <linux/kernel.h>
   9#include <linux/sched.h>
  10#include <linux/sched/task_stack.h>
  11#include <linux/mm.h>
  12#include <linux/smp.h>
  13#include <linux/errno.h>
  14#include <linux/slab.h>
  15#include <linux/ptrace.h>
 
  16#include <linux/tracehook.h>
  17#include <linux/user.h>
  18#include <linux/elf.h>
  19#include <linux/security.h>
  20#include <linux/audit.h>
  21#include <linux/seccomp.h>
  22#include <linux/signal.h>
  23#include <linux/perf_event.h>
  24#include <linux/hw_breakpoint.h>
  25#include <linux/rcupdate.h>
  26#include <linux/export.h>
  27#include <linux/context_tracking.h>
  28#include <linux/nospec.h>
  29
  30#include <linux/uaccess.h>
  31#include <asm/pgtable.h>
 
  32#include <asm/processor.h>
  33#include <asm/fpu/internal.h>
  34#include <asm/fpu/signal.h>
  35#include <asm/fpu/regset.h>
  36#include <asm/debugreg.h>
  37#include <asm/ldt.h>
  38#include <asm/desc.h>
  39#include <asm/prctl.h>
  40#include <asm/proto.h>
  41#include <asm/hw_breakpoint.h>
  42#include <asm/traps.h>
  43#include <asm/syscall.h>
  44#include <asm/fsgsbase.h>
  45
  46#include "tls.h"
  47
 
 
 
  48enum x86_regset {
  49	REGSET_GENERAL,
  50	REGSET_FP,
  51	REGSET_XFP,
  52	REGSET_IOPERM64 = REGSET_XFP,
  53	REGSET_XSTATE,
  54	REGSET_TLS,
  55	REGSET_IOPERM32,
  56};
  57
  58struct pt_regs_offset {
  59	const char *name;
  60	int offset;
  61};
  62
  63#define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
  64#define REG_OFFSET_END {.name = NULL, .offset = 0}
  65
  66static const struct pt_regs_offset regoffset_table[] = {
  67#ifdef CONFIG_X86_64
  68	REG_OFFSET_NAME(r15),
  69	REG_OFFSET_NAME(r14),
  70	REG_OFFSET_NAME(r13),
  71	REG_OFFSET_NAME(r12),
  72	REG_OFFSET_NAME(r11),
  73	REG_OFFSET_NAME(r10),
  74	REG_OFFSET_NAME(r9),
  75	REG_OFFSET_NAME(r8),
  76#endif
  77	REG_OFFSET_NAME(bx),
  78	REG_OFFSET_NAME(cx),
  79	REG_OFFSET_NAME(dx),
  80	REG_OFFSET_NAME(si),
  81	REG_OFFSET_NAME(di),
  82	REG_OFFSET_NAME(bp),
  83	REG_OFFSET_NAME(ax),
  84#ifdef CONFIG_X86_32
  85	REG_OFFSET_NAME(ds),
  86	REG_OFFSET_NAME(es),
  87	REG_OFFSET_NAME(fs),
  88	REG_OFFSET_NAME(gs),
  89#endif
  90	REG_OFFSET_NAME(orig_ax),
  91	REG_OFFSET_NAME(ip),
  92	REG_OFFSET_NAME(cs),
  93	REG_OFFSET_NAME(flags),
  94	REG_OFFSET_NAME(sp),
  95	REG_OFFSET_NAME(ss),
  96	REG_OFFSET_END,
  97};
  98
  99/**
 100 * regs_query_register_offset() - query register offset from its name
 101 * @name:	the name of a register
 102 *
 103 * regs_query_register_offset() returns the offset of a register in struct
 104 * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 105 */
 106int regs_query_register_offset(const char *name)
 107{
 108	const struct pt_regs_offset *roff;
 109	for (roff = regoffset_table; roff->name != NULL; roff++)
 110		if (!strcmp(roff->name, name))
 111			return roff->offset;
 112	return -EINVAL;
 113}
 114
 115/**
 116 * regs_query_register_name() - query register name from its offset
 117 * @offset:	the offset of a register in struct pt_regs.
 118 *
 119 * regs_query_register_name() returns the name of a register from its
 120 * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
 121 */
 122const char *regs_query_register_name(unsigned int offset)
 123{
 124	const struct pt_regs_offset *roff;
 125	for (roff = regoffset_table; roff->name != NULL; roff++)
 126		if (roff->offset == offset)
 127			return roff->name;
 128	return NULL;
 129}
 130
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 131/*
 132 * does not yet catch signals sent when the child dies.
 133 * in exit.c or in signal.c.
 134 */
 135
 136/*
 137 * Determines which flags the user has access to [1 = access, 0 = no access].
 138 */
 139#define FLAG_MASK_32		((unsigned long)			\
 140				 (X86_EFLAGS_CF | X86_EFLAGS_PF |	\
 141				  X86_EFLAGS_AF | X86_EFLAGS_ZF |	\
 142				  X86_EFLAGS_SF | X86_EFLAGS_TF |	\
 143				  X86_EFLAGS_DF | X86_EFLAGS_OF |	\
 144				  X86_EFLAGS_RF | X86_EFLAGS_AC))
 145
 146/*
 147 * Determines whether a value may be installed in a segment register.
 148 */
 149static inline bool invalid_selector(u16 value)
 150{
 151	return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
 152}
 153
 154#ifdef CONFIG_X86_32
 155
 156#define FLAG_MASK		FLAG_MASK_32
 157
 158static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
 159{
 160	BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
 161	return &regs->bx + (regno >> 2);
 162}
 163
 164static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 165{
 166	/*
 167	 * Returning the value truncates it to 16 bits.
 168	 */
 169	unsigned int retval;
 170	if (offset != offsetof(struct user_regs_struct, gs))
 171		retval = *pt_regs_access(task_pt_regs(task), offset);
 172	else {
 173		if (task == current)
 174			retval = get_user_gs(task_pt_regs(task));
 175		else
 176			retval = task_user_gs(task);
 177	}
 178	return retval;
 179}
 180
 181static int set_segment_reg(struct task_struct *task,
 182			   unsigned long offset, u16 value)
 183{
 184	/*
 185	 * The value argument was already truncated to 16 bits.
 186	 */
 187	if (invalid_selector(value))
 188		return -EIO;
 189
 190	/*
 191	 * For %cs and %ss we cannot permit a null selector.
 192	 * We can permit a bogus selector as long as it has USER_RPL.
 193	 * Null selectors are fine for other segment registers, but
 194	 * we will never get back to user mode with invalid %cs or %ss
 195	 * and will take the trap in iret instead.  Much code relies
 196	 * on user_mode() to distinguish a user trap frame (which can
 197	 * safely use invalid selectors) from a kernel trap frame.
 198	 */
 199	switch (offset) {
 200	case offsetof(struct user_regs_struct, cs):
 201	case offsetof(struct user_regs_struct, ss):
 202		if (unlikely(value == 0))
 203			return -EIO;
 204		/* Else, fall through */
 205
 206	default:
 207		*pt_regs_access(task_pt_regs(task), offset) = value;
 208		break;
 209
 210	case offsetof(struct user_regs_struct, gs):
 211		if (task == current)
 212			set_user_gs(task_pt_regs(task), value);
 213		else
 214			task_user_gs(task) = value;
 215	}
 216
 217	return 0;
 218}
 219
 220#else  /* CONFIG_X86_64 */
 221
 222#define FLAG_MASK		(FLAG_MASK_32 | X86_EFLAGS_NT)
 223
 224static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
 225{
 226	BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
 227	return &regs->r15 + (offset / sizeof(regs->r15));
 228}
 229
 230static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 231{
 232	/*
 233	 * Returning the value truncates it to 16 bits.
 234	 */
 235	unsigned int seg;
 236
 237	switch (offset) {
 238	case offsetof(struct user_regs_struct, fs):
 239		if (task == current) {
 240			/* Older gas can't assemble movq %?s,%r?? */
 241			asm("movl %%fs,%0" : "=r" (seg));
 242			return seg;
 243		}
 244		return task->thread.fsindex;
 245	case offsetof(struct user_regs_struct, gs):
 246		if (task == current) {
 247			asm("movl %%gs,%0" : "=r" (seg));
 248			return seg;
 249		}
 250		return task->thread.gsindex;
 251	case offsetof(struct user_regs_struct, ds):
 252		if (task == current) {
 253			asm("movl %%ds,%0" : "=r" (seg));
 254			return seg;
 255		}
 256		return task->thread.ds;
 257	case offsetof(struct user_regs_struct, es):
 258		if (task == current) {
 259			asm("movl %%es,%0" : "=r" (seg));
 260			return seg;
 261		}
 262		return task->thread.es;
 263
 264	case offsetof(struct user_regs_struct, cs):
 265	case offsetof(struct user_regs_struct, ss):
 266		break;
 267	}
 268	return *pt_regs_access(task_pt_regs(task), offset);
 269}
 270
 271static int set_segment_reg(struct task_struct *task,
 272			   unsigned long offset, u16 value)
 273{
 274	/*
 275	 * The value argument was already truncated to 16 bits.
 276	 */
 277	if (invalid_selector(value))
 278		return -EIO;
 279
 280	switch (offset) {
 281	case offsetof(struct user_regs_struct,fs):
 
 
 
 
 
 
 
 
 
 282		task->thread.fsindex = value;
 283		if (task == current)
 284			loadsegment(fs, task->thread.fsindex);
 285		break;
 286	case offsetof(struct user_regs_struct,gs):
 
 
 
 
 
 
 
 
 
 287		task->thread.gsindex = value;
 288		if (task == current)
 289			load_gs_index(task->thread.gsindex);
 290		break;
 291	case offsetof(struct user_regs_struct,ds):
 292		task->thread.ds = value;
 293		if (task == current)
 294			loadsegment(ds, task->thread.ds);
 295		break;
 296	case offsetof(struct user_regs_struct,es):
 297		task->thread.es = value;
 298		if (task == current)
 299			loadsegment(es, task->thread.es);
 300		break;
 301
 302		/*
 303		 * Can't actually change these in 64-bit mode.
 304		 */
 305	case offsetof(struct user_regs_struct,cs):
 306		if (unlikely(value == 0))
 307			return -EIO;
 308		task_pt_regs(task)->cs = value;
 
 
 
 309		break;
 310	case offsetof(struct user_regs_struct,ss):
 311		if (unlikely(value == 0))
 312			return -EIO;
 313		task_pt_regs(task)->ss = value;
 
 
 
 314		break;
 315	}
 316
 317	return 0;
 318}
 319
 320#endif	/* CONFIG_X86_32 */
 321
 322static unsigned long get_flags(struct task_struct *task)
 323{
 324	unsigned long retval = task_pt_regs(task)->flags;
 325
 326	/*
 327	 * If the debugger set TF, hide it from the readout.
 328	 */
 329	if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 330		retval &= ~X86_EFLAGS_TF;
 331
 332	return retval;
 333}
 334
 335static int set_flags(struct task_struct *task, unsigned long value)
 336{
 337	struct pt_regs *regs = task_pt_regs(task);
 338
 339	/*
 340	 * If the user value contains TF, mark that
 341	 * it was not "us" (the debugger) that set it.
 342	 * If not, make sure it stays set if we had.
 343	 */
 344	if (value & X86_EFLAGS_TF)
 345		clear_tsk_thread_flag(task, TIF_FORCED_TF);
 346	else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 347		value |= X86_EFLAGS_TF;
 348
 349	regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
 350
 351	return 0;
 352}
 353
 354static int putreg(struct task_struct *child,
 355		  unsigned long offset, unsigned long value)
 356{
 357	switch (offset) {
 358	case offsetof(struct user_regs_struct, cs):
 359	case offsetof(struct user_regs_struct, ds):
 360	case offsetof(struct user_regs_struct, es):
 361	case offsetof(struct user_regs_struct, fs):
 362	case offsetof(struct user_regs_struct, gs):
 363	case offsetof(struct user_regs_struct, ss):
 364		return set_segment_reg(child, offset, value);
 365
 366	case offsetof(struct user_regs_struct, flags):
 367		return set_flags(child, value);
 368
 369#ifdef CONFIG_X86_64
 370	case offsetof(struct user_regs_struct,fs_base):
 371		if (value >= TASK_SIZE_MAX)
 372			return -EIO;
 373		/*
 374		 * When changing the FS base, use do_arch_prctl_64()
 375		 * to set the index to zero and to set the base
 376		 * as requested.
 377		 */
 378		if (child->thread.fsbase != value)
 379			return do_arch_prctl_64(child, ARCH_SET_FS, value);
 380		return 0;
 381	case offsetof(struct user_regs_struct,gs_base):
 382		/*
 383		 * Exactly the same here as the %fs handling above.
 384		 */
 385		if (value >= TASK_SIZE_MAX)
 386			return -EIO;
 387		if (child->thread.gsbase != value)
 388			return do_arch_prctl_64(child, ARCH_SET_GS, value);
 389		return 0;
 390#endif
 391	}
 392
 393	*pt_regs_access(task_pt_regs(child), offset) = value;
 394	return 0;
 395}
 396
 397static unsigned long getreg(struct task_struct *task, unsigned long offset)
 398{
 399	switch (offset) {
 400	case offsetof(struct user_regs_struct, cs):
 401	case offsetof(struct user_regs_struct, ds):
 402	case offsetof(struct user_regs_struct, es):
 403	case offsetof(struct user_regs_struct, fs):
 404	case offsetof(struct user_regs_struct, gs):
 405	case offsetof(struct user_regs_struct, ss):
 406		return get_segment_reg(task, offset);
 407
 408	case offsetof(struct user_regs_struct, flags):
 409		return get_flags(task);
 410
 411#ifdef CONFIG_X86_64
 412	case offsetof(struct user_regs_struct, fs_base):
 413		return x86_fsbase_read_task(task);
 414	case offsetof(struct user_regs_struct, gs_base):
 415		return x86_gsbase_read_task(task);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 416#endif
 417	}
 418
 419	return *pt_regs_access(task_pt_regs(task), offset);
 420}
 421
 422static int genregs_get(struct task_struct *target,
 423		       const struct user_regset *regset,
 424		       unsigned int pos, unsigned int count,
 425		       void *kbuf, void __user *ubuf)
 426{
 427	if (kbuf) {
 428		unsigned long *k = kbuf;
 429		while (count >= sizeof(*k)) {
 430			*k++ = getreg(target, pos);
 431			count -= sizeof(*k);
 432			pos += sizeof(*k);
 433		}
 434	} else {
 435		unsigned long __user *u = ubuf;
 436		while (count >= sizeof(*u)) {
 437			if (__put_user(getreg(target, pos), u++))
 438				return -EFAULT;
 439			count -= sizeof(*u);
 440			pos += sizeof(*u);
 441		}
 442	}
 443
 444	return 0;
 445}
 446
 447static int genregs_set(struct task_struct *target,
 448		       const struct user_regset *regset,
 449		       unsigned int pos, unsigned int count,
 450		       const void *kbuf, const void __user *ubuf)
 451{
 452	int ret = 0;
 453	if (kbuf) {
 454		const unsigned long *k = kbuf;
 455		while (count >= sizeof(*k) && !ret) {
 456			ret = putreg(target, pos, *k++);
 457			count -= sizeof(*k);
 458			pos += sizeof(*k);
 459		}
 460	} else {
 461		const unsigned long  __user *u = ubuf;
 462		while (count >= sizeof(*u) && !ret) {
 463			unsigned long word;
 464			ret = __get_user(word, u++);
 465			if (ret)
 466				break;
 467			ret = putreg(target, pos, word);
 468			count -= sizeof(*u);
 469			pos += sizeof(*u);
 470		}
 471	}
 472	return ret;
 473}
 474
 475static void ptrace_triggered(struct perf_event *bp,
 476			     struct perf_sample_data *data,
 477			     struct pt_regs *regs)
 478{
 479	int i;
 480	struct thread_struct *thread = &(current->thread);
 481
 482	/*
 483	 * Store in the virtual DR6 register the fact that the breakpoint
 484	 * was hit so the thread's debugger will see it.
 485	 */
 486	for (i = 0; i < HBP_NUM; i++) {
 487		if (thread->ptrace_bps[i] == bp)
 488			break;
 489	}
 490
 491	thread->debugreg6 |= (DR_TRAP0 << i);
 492}
 493
 494/*
 495 * Walk through every ptrace breakpoints for this thread and
 496 * build the dr7 value on top of their attributes.
 497 *
 498 */
 499static unsigned long ptrace_get_dr7(struct perf_event *bp[])
 500{
 501	int i;
 502	int dr7 = 0;
 503	struct arch_hw_breakpoint *info;
 504
 505	for (i = 0; i < HBP_NUM; i++) {
 506		if (bp[i] && !bp[i]->attr.disabled) {
 507			info = counter_arch_bp(bp[i]);
 508			dr7 |= encode_dr7(i, info->len, info->type);
 509		}
 510	}
 511
 512	return dr7;
 513}
 514
 515static int ptrace_fill_bp_fields(struct perf_event_attr *attr,
 516					int len, int type, bool disabled)
 
 517{
 518	int err, bp_len, bp_type;
 519
 520	err = arch_bp_generic_fields(len, type, &bp_len, &bp_type);
 521	if (!err) {
 522		attr->bp_len = bp_len;
 523		attr->bp_type = bp_type;
 524		attr->disabled = disabled;
 525	}
 526
 527	return err;
 528}
 529
 530static struct perf_event *
 531ptrace_register_breakpoint(struct task_struct *tsk, int len, int type,
 532				unsigned long addr, bool disabled)
 533{
 534	struct perf_event_attr attr;
 535	int err;
 
 
 536
 537	ptrace_breakpoint_init(&attr);
 538	attr.bp_addr = addr;
 539
 540	err = ptrace_fill_bp_fields(&attr, len, type, disabled);
 541	if (err)
 542		return ERR_PTR(err);
 543
 544	return register_user_hw_breakpoint(&attr, ptrace_triggered,
 545						 NULL, tsk);
 546}
 547
 548static int ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
 549					int disabled)
 550{
 551	struct perf_event_attr attr = bp->attr;
 552	int err;
 553
 554	err = ptrace_fill_bp_fields(&attr, len, type, disabled);
 555	if (err)
 556		return err;
 557
 
 
 
 
 
 558	return modify_user_hw_breakpoint(bp, &attr);
 559}
 560
 561/*
 562 * Handle ptrace writes to debug register 7.
 563 */
 564static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
 565{
 566	struct thread_struct *thread = &tsk->thread;
 567	unsigned long old_dr7;
 568	bool second_pass = false;
 569	int i, rc, ret = 0;
 
 
 
 
 
 570
 571	data &= ~DR_CONTROL_RESERVED;
 572	old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
 573
 574restore:
 575	rc = 0;
 
 
 
 576	for (i = 0; i < HBP_NUM; i++) {
 577		unsigned len, type;
 578		bool disabled = !decode_dr7(data, i, &len, &type);
 579		struct perf_event *bp = thread->ptrace_bps[i];
 580
 581		if (!bp) {
 582			if (disabled)
 583				continue;
 584
 585			bp = ptrace_register_breakpoint(tsk,
 586					len, type, 0, disabled);
 587			if (IS_ERR(bp)) {
 588				rc = PTR_ERR(bp);
 589				break;
 590			}
 591
 592			thread->ptrace_bps[i] = bp;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 593			continue;
 594		}
 595
 596		rc = ptrace_modify_breakpoint(bp, len, type, disabled);
 597		if (rc)
 598			break;
 599	}
 600
 601	/* Restore if the first pass failed, second_pass shouldn't fail. */
 602	if (rc && !WARN_ON(second_pass)) {
 603		ret = rc;
 604		data = old_dr7;
 605		second_pass = true;
 
 
 
 
 606		goto restore;
 607	}
 608
 609	return ret;
 
 
 610}
 611
 612/*
 613 * Handle PTRACE_PEEKUSR calls for the debug register area.
 614 */
 615static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
 616{
 617	struct thread_struct *thread = &tsk->thread;
 618	unsigned long val = 0;
 619
 620	if (n < HBP_NUM) {
 621		int index = array_index_nospec(n, HBP_NUM);
 622		struct perf_event *bp = thread->ptrace_bps[index];
 
 
 623
 624		if (bp)
 
 
 
 625			val = bp->hw.info.address;
 
 
 626	} else if (n == 6) {
 627		val = thread->debugreg6;
 628	} else if (n == 7) {
 629		val = thread->ptrace_dr7;
 630	}
 631	return val;
 632}
 633
 634static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
 635				      unsigned long addr)
 636{
 
 637	struct thread_struct *t = &tsk->thread;
 638	struct perf_event *bp = t->ptrace_bps[nr];
 639	int err = 0;
 640
 641	if (!bp) {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 642		/*
 643		 * Put stub len and type to create an inactive but correct bp.
 644		 *
 645		 * CHECKME: the previous code returned -EIO if the addr wasn't
 646		 * a valid task virtual addr. The new one will return -EINVAL in
 647		 *  this case.
 648		 * -EINVAL may be what we want for in-kernel breakpoints users,
 649		 * but -EIO looks better for ptrace, since we refuse a register
 650		 * writing for the user. And anyway this is the previous
 651		 * behaviour.
 652		 */
 653		bp = ptrace_register_breakpoint(tsk,
 654				X86_BREAKPOINT_LEN_1, X86_BREAKPOINT_WRITE,
 655				addr, true);
 656		if (IS_ERR(bp))
 657			err = PTR_ERR(bp);
 658		else
 659			t->ptrace_bps[nr] = bp;
 
 
 660	} else {
 661		struct perf_event_attr attr = bp->attr;
 662
 
 663		attr.bp_addr = addr;
 664		err = modify_user_hw_breakpoint(bp, &attr);
 665	}
 666
 
 
 667	return err;
 668}
 669
 670/*
 671 * Handle PTRACE_POKEUSR calls for the debug register area.
 672 */
 673static int ptrace_set_debugreg(struct task_struct *tsk, int n,
 674			       unsigned long val)
 675{
 676	struct thread_struct *thread = &tsk->thread;
 
 
 677	/* There are no DR4 or DR5 registers */
 678	int rc = -EIO;
 
 679
 
 
 
 
 680	if (n < HBP_NUM) {
 681		rc = ptrace_set_breakpoint_addr(tsk, n, val);
 682	} else if (n == 6) {
 683		thread->debugreg6 = val;
 684		rc = 0;
 685	} else if (n == 7) {
 
 686		rc = ptrace_write_dr7(tsk, val);
 687		if (!rc)
 688			thread->ptrace_dr7 = val;
 689	}
 
 
 690	return rc;
 691}
 692
 693/*
 694 * These access the current or another (stopped) task's io permission
 695 * bitmap for debugging or core dump.
 696 */
 697static int ioperm_active(struct task_struct *target,
 698			 const struct user_regset *regset)
 699{
 700	return target->thread.io_bitmap_max / regset->size;
 701}
 702
 703static int ioperm_get(struct task_struct *target,
 704		      const struct user_regset *regset,
 705		      unsigned int pos, unsigned int count,
 706		      void *kbuf, void __user *ubuf)
 707{
 708	if (!target->thread.io_bitmap_ptr)
 709		return -ENXIO;
 710
 711	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 712				   target->thread.io_bitmap_ptr,
 713				   0, IO_BITMAP_BYTES);
 714}
 715
 716/*
 717 * Called by kernel/ptrace.c when detaching..
 718 *
 719 * Make sure the single step bit is not set.
 720 */
 721void ptrace_disable(struct task_struct *child)
 722{
 723	user_disable_single_step(child);
 
 
 
 724}
 725
 726#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 727static const struct user_regset_view user_x86_32_view; /* Initialized below. */
 728#endif
 729
 730long arch_ptrace(struct task_struct *child, long request,
 731		 unsigned long addr, unsigned long data)
 732{
 733	int ret;
 734	unsigned long __user *datap = (unsigned long __user *)data;
 735
 736	switch (request) {
 737	/* read the word at location addr in the USER area. */
 738	case PTRACE_PEEKUSR: {
 739		unsigned long tmp;
 740
 741		ret = -EIO;
 742		if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 743			break;
 744
 745		tmp = 0;  /* Default return condition */
 746		if (addr < sizeof(struct user_regs_struct))
 747			tmp = getreg(child, addr);
 748		else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 749			 addr <= offsetof(struct user, u_debugreg[7])) {
 750			addr -= offsetof(struct user, u_debugreg[0]);
 751			tmp = ptrace_get_debugreg(child, addr / sizeof(data));
 752		}
 753		ret = put_user(tmp, datap);
 754		break;
 755	}
 756
 757	case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
 758		ret = -EIO;
 759		if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 760			break;
 761
 762		if (addr < sizeof(struct user_regs_struct))
 763			ret = putreg(child, addr, data);
 764		else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 765			 addr <= offsetof(struct user, u_debugreg[7])) {
 766			addr -= offsetof(struct user, u_debugreg[0]);
 767			ret = ptrace_set_debugreg(child,
 768						  addr / sizeof(data), data);
 769		}
 770		break;
 771
 772	case PTRACE_GETREGS:	/* Get all gp regs from the child. */
 773		return copy_regset_to_user(child,
 774					   task_user_regset_view(current),
 775					   REGSET_GENERAL,
 776					   0, sizeof(struct user_regs_struct),
 777					   datap);
 778
 779	case PTRACE_SETREGS:	/* Set all gp regs in the child. */
 780		return copy_regset_from_user(child,
 781					     task_user_regset_view(current),
 782					     REGSET_GENERAL,
 783					     0, sizeof(struct user_regs_struct),
 784					     datap);
 785
 786	case PTRACE_GETFPREGS:	/* Get the child FPU state. */
 787		return copy_regset_to_user(child,
 788					   task_user_regset_view(current),
 789					   REGSET_FP,
 790					   0, sizeof(struct user_i387_struct),
 791					   datap);
 792
 793	case PTRACE_SETFPREGS:	/* Set the child FPU state. */
 794		return copy_regset_from_user(child,
 795					     task_user_regset_view(current),
 796					     REGSET_FP,
 797					     0, sizeof(struct user_i387_struct),
 798					     datap);
 799
 800#ifdef CONFIG_X86_32
 801	case PTRACE_GETFPXREGS:	/* Get the child extended FPU state. */
 802		return copy_regset_to_user(child, &user_x86_32_view,
 803					   REGSET_XFP,
 804					   0, sizeof(struct user_fxsr_struct),
 805					   datap) ? -EIO : 0;
 806
 807	case PTRACE_SETFPXREGS:	/* Set the child extended FPU state. */
 808		return copy_regset_from_user(child, &user_x86_32_view,
 809					     REGSET_XFP,
 810					     0, sizeof(struct user_fxsr_struct),
 811					     datap) ? -EIO : 0;
 812#endif
 813
 814#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 815	case PTRACE_GET_THREAD_AREA:
 816		if ((int) addr < 0)
 817			return -EIO;
 818		ret = do_get_thread_area(child, addr,
 819					(struct user_desc __user *)data);
 820		break;
 821
 822	case PTRACE_SET_THREAD_AREA:
 823		if ((int) addr < 0)
 824			return -EIO;
 825		ret = do_set_thread_area(child, addr,
 826					(struct user_desc __user *)data, 0);
 827		break;
 828#endif
 829
 830#ifdef CONFIG_X86_64
 831		/* normal 64bit interface to access TLS data.
 832		   Works just like arch_prctl, except that the arguments
 833		   are reversed. */
 834	case PTRACE_ARCH_PRCTL:
 835		ret = do_arch_prctl_64(child, data, addr);
 836		break;
 837#endif
 838
 839	default:
 840		ret = ptrace_request(child, request, addr, data);
 841		break;
 842	}
 843
 844	return ret;
 845}
 846
 847#ifdef CONFIG_IA32_EMULATION
 848
 849#include <linux/compat.h>
 850#include <linux/syscalls.h>
 851#include <asm/ia32.h>
 852#include <asm/user32.h>
 853
 854#define R32(l,q)							\
 855	case offsetof(struct user32, regs.l):				\
 856		regs->q = value; break
 857
 858#define SEG32(rs)							\
 859	case offsetof(struct user32, regs.rs):				\
 860		return set_segment_reg(child,				\
 861				       offsetof(struct user_regs_struct, rs), \
 862				       value);				\
 863		break
 864
 865static int putreg32(struct task_struct *child, unsigned regno, u32 value)
 866{
 867	struct pt_regs *regs = task_pt_regs(child);
 868
 869	switch (regno) {
 870
 871	SEG32(cs);
 872	SEG32(ds);
 873	SEG32(es);
 874	SEG32(fs);
 875	SEG32(gs);
 876	SEG32(ss);
 877
 878	R32(ebx, bx);
 879	R32(ecx, cx);
 880	R32(edx, dx);
 881	R32(edi, di);
 882	R32(esi, si);
 883	R32(ebp, bp);
 884	R32(eax, ax);
 885	R32(eip, ip);
 886	R32(esp, sp);
 887
 888	case offsetof(struct user32, regs.orig_eax):
 889		/*
 890		 * Warning: bizarre corner case fixup here.  A 32-bit
 891		 * debugger setting orig_eax to -1 wants to disable
 892		 * syscall restart.  Make sure that the syscall
 893		 * restart code sign-extends orig_ax.  Also make sure
 894		 * we interpret the -ERESTART* codes correctly if
 895		 * loaded into regs->ax in case the task is not
 896		 * actually still sitting at the exit from a 32-bit
 897		 * syscall with TS_COMPAT still set.
 898		 */
 899		regs->orig_ax = value;
 900		if (syscall_get_nr(child, regs) >= 0)
 901			child->thread_info.status |= TS_I386_REGS_POKED;
 902		break;
 903
 904	case offsetof(struct user32, regs.eflags):
 905		return set_flags(child, value);
 906
 907	case offsetof(struct user32, u_debugreg[0]) ...
 908		offsetof(struct user32, u_debugreg[7]):
 909		regno -= offsetof(struct user32, u_debugreg[0]);
 910		return ptrace_set_debugreg(child, regno / 4, value);
 911
 912	default:
 913		if (regno > sizeof(struct user32) || (regno & 3))
 914			return -EIO;
 915
 916		/*
 917		 * Other dummy fields in the virtual user structure
 918		 * are ignored
 919		 */
 920		break;
 921	}
 922	return 0;
 923}
 924
 925#undef R32
 926#undef SEG32
 927
 928#define R32(l,q)							\
 929	case offsetof(struct user32, regs.l):				\
 930		*val = regs->q; break
 931
 932#define SEG32(rs)							\
 933	case offsetof(struct user32, regs.rs):				\
 934		*val = get_segment_reg(child,				\
 935				       offsetof(struct user_regs_struct, rs)); \
 936		break
 937
 938static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
 939{
 940	struct pt_regs *regs = task_pt_regs(child);
 941
 942	switch (regno) {
 943
 944	SEG32(ds);
 945	SEG32(es);
 946	SEG32(fs);
 947	SEG32(gs);
 948
 949	R32(cs, cs);
 950	R32(ss, ss);
 951	R32(ebx, bx);
 952	R32(ecx, cx);
 953	R32(edx, dx);
 954	R32(edi, di);
 955	R32(esi, si);
 956	R32(ebp, bp);
 957	R32(eax, ax);
 958	R32(orig_eax, orig_ax);
 959	R32(eip, ip);
 960	R32(esp, sp);
 961
 962	case offsetof(struct user32, regs.eflags):
 963		*val = get_flags(child);
 964		break;
 965
 966	case offsetof(struct user32, u_debugreg[0]) ...
 967		offsetof(struct user32, u_debugreg[7]):
 968		regno -= offsetof(struct user32, u_debugreg[0]);
 969		*val = ptrace_get_debugreg(child, regno / 4);
 970		break;
 971
 972	default:
 973		if (regno > sizeof(struct user32) || (regno & 3))
 974			return -EIO;
 975
 976		/*
 977		 * Other dummy fields in the virtual user structure
 978		 * are ignored
 979		 */
 980		*val = 0;
 981		break;
 982	}
 983	return 0;
 984}
 985
 986#undef R32
 987#undef SEG32
 988
 989static int genregs32_get(struct task_struct *target,
 990			 const struct user_regset *regset,
 991			 unsigned int pos, unsigned int count,
 992			 void *kbuf, void __user *ubuf)
 993{
 994	if (kbuf) {
 995		compat_ulong_t *k = kbuf;
 996		while (count >= sizeof(*k)) {
 997			getreg32(target, pos, k++);
 998			count -= sizeof(*k);
 999			pos += sizeof(*k);
1000		}
1001	} else {
1002		compat_ulong_t __user *u = ubuf;
1003		while (count >= sizeof(*u)) {
1004			compat_ulong_t word;
1005			getreg32(target, pos, &word);
1006			if (__put_user(word, u++))
1007				return -EFAULT;
1008			count -= sizeof(*u);
1009			pos += sizeof(*u);
1010		}
1011	}
1012
1013	return 0;
1014}
1015
1016static int genregs32_set(struct task_struct *target,
1017			 const struct user_regset *regset,
1018			 unsigned int pos, unsigned int count,
1019			 const void *kbuf, const void __user *ubuf)
1020{
1021	int ret = 0;
1022	if (kbuf) {
1023		const compat_ulong_t *k = kbuf;
1024		while (count >= sizeof(*k) && !ret) {
1025			ret = putreg32(target, pos, *k++);
1026			count -= sizeof(*k);
1027			pos += sizeof(*k);
1028		}
1029	} else {
1030		const compat_ulong_t __user *u = ubuf;
1031		while (count >= sizeof(*u) && !ret) {
1032			compat_ulong_t word;
1033			ret = __get_user(word, u++);
1034			if (ret)
1035				break;
1036			ret = putreg32(target, pos, word);
1037			count -= sizeof(*u);
1038			pos += sizeof(*u);
1039		}
1040	}
1041	return ret;
1042}
1043
1044static long ia32_arch_ptrace(struct task_struct *child, compat_long_t request,
1045			     compat_ulong_t caddr, compat_ulong_t cdata)
1046{
1047	unsigned long addr = caddr;
1048	unsigned long data = cdata;
1049	void __user *datap = compat_ptr(data);
1050	int ret;
1051	__u32 val;
1052
1053	switch (request) {
1054	case PTRACE_PEEKUSR:
1055		ret = getreg32(child, addr, &val);
1056		if (ret == 0)
1057			ret = put_user(val, (__u32 __user *)datap);
1058		break;
1059
1060	case PTRACE_POKEUSR:
1061		ret = putreg32(child, addr, data);
1062		break;
1063
1064	case PTRACE_GETREGS:	/* Get all gp regs from the child. */
1065		return copy_regset_to_user(child, &user_x86_32_view,
1066					   REGSET_GENERAL,
1067					   0, sizeof(struct user_regs_struct32),
1068					   datap);
1069
1070	case PTRACE_SETREGS:	/* Set all gp regs in the child. */
1071		return copy_regset_from_user(child, &user_x86_32_view,
1072					     REGSET_GENERAL, 0,
1073					     sizeof(struct user_regs_struct32),
1074					     datap);
1075
1076	case PTRACE_GETFPREGS:	/* Get the child FPU state. */
1077		return copy_regset_to_user(child, &user_x86_32_view,
1078					   REGSET_FP, 0,
1079					   sizeof(struct user_i387_ia32_struct),
1080					   datap);
1081
1082	case PTRACE_SETFPREGS:	/* Set the child FPU state. */
1083		return copy_regset_from_user(
1084			child, &user_x86_32_view, REGSET_FP,
1085			0, sizeof(struct user_i387_ia32_struct), datap);
1086
1087	case PTRACE_GETFPXREGS:	/* Get the child extended FPU state. */
1088		return copy_regset_to_user(child, &user_x86_32_view,
1089					   REGSET_XFP, 0,
1090					   sizeof(struct user32_fxsr_struct),
1091					   datap);
1092
1093	case PTRACE_SETFPXREGS:	/* Set the child extended FPU state. */
1094		return copy_regset_from_user(child, &user_x86_32_view,
1095					     REGSET_XFP, 0,
1096					     sizeof(struct user32_fxsr_struct),
1097					     datap);
1098
1099	case PTRACE_GET_THREAD_AREA:
1100	case PTRACE_SET_THREAD_AREA:
1101		return arch_ptrace(child, request, addr, data);
1102
1103	default:
1104		return compat_ptrace_request(child, request, addr, data);
1105	}
1106
1107	return ret;
1108}
1109#endif /* CONFIG_IA32_EMULATION */
1110
1111#ifdef CONFIG_X86_X32_ABI
1112static long x32_arch_ptrace(struct task_struct *child,
1113			    compat_long_t request, compat_ulong_t caddr,
1114			    compat_ulong_t cdata)
1115{
1116	unsigned long addr = caddr;
1117	unsigned long data = cdata;
1118	void __user *datap = compat_ptr(data);
1119	int ret;
1120
1121	switch (request) {
1122	/* Read 32bits at location addr in the USER area.  Only allow
1123	   to return the lower 32bits of segment and debug registers.  */
1124	case PTRACE_PEEKUSR: {
1125		u32 tmp;
1126
1127		ret = -EIO;
1128		if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1129		    addr < offsetof(struct user_regs_struct, cs))
1130			break;
1131
1132		tmp = 0;  /* Default return condition */
1133		if (addr < sizeof(struct user_regs_struct))
1134			tmp = getreg(child, addr);
1135		else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1136			 addr <= offsetof(struct user, u_debugreg[7])) {
1137			addr -= offsetof(struct user, u_debugreg[0]);
1138			tmp = ptrace_get_debugreg(child, addr / sizeof(data));
1139		}
1140		ret = put_user(tmp, (__u32 __user *)datap);
1141		break;
1142	}
1143
1144	/* Write the word at location addr in the USER area.  Only allow
1145	   to update segment and debug registers with the upper 32bits
1146	   zero-extended. */
1147	case PTRACE_POKEUSR:
1148		ret = -EIO;
1149		if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1150		    addr < offsetof(struct user_regs_struct, cs))
1151			break;
1152
1153		if (addr < sizeof(struct user_regs_struct))
1154			ret = putreg(child, addr, data);
1155		else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1156			 addr <= offsetof(struct user, u_debugreg[7])) {
1157			addr -= offsetof(struct user, u_debugreg[0]);
1158			ret = ptrace_set_debugreg(child,
1159						  addr / sizeof(data), data);
1160		}
1161		break;
1162
1163	case PTRACE_GETREGS:	/* Get all gp regs from the child. */
1164		return copy_regset_to_user(child,
1165					   task_user_regset_view(current),
1166					   REGSET_GENERAL,
1167					   0, sizeof(struct user_regs_struct),
1168					   datap);
1169
1170	case PTRACE_SETREGS:	/* Set all gp regs in the child. */
1171		return copy_regset_from_user(child,
1172					     task_user_regset_view(current),
1173					     REGSET_GENERAL,
1174					     0, sizeof(struct user_regs_struct),
1175					     datap);
1176
1177	case PTRACE_GETFPREGS:	/* Get the child FPU state. */
1178		return copy_regset_to_user(child,
1179					   task_user_regset_view(current),
1180					   REGSET_FP,
1181					   0, sizeof(struct user_i387_struct),
1182					   datap);
1183
1184	case PTRACE_SETFPREGS:	/* Set the child FPU state. */
1185		return copy_regset_from_user(child,
1186					     task_user_regset_view(current),
1187					     REGSET_FP,
1188					     0, sizeof(struct user_i387_struct),
1189					     datap);
1190
1191	default:
1192		return compat_ptrace_request(child, request, addr, data);
1193	}
1194
1195	return ret;
1196}
1197#endif
1198
1199#ifdef CONFIG_COMPAT
1200long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1201			compat_ulong_t caddr, compat_ulong_t cdata)
1202{
1203#ifdef CONFIG_X86_X32_ABI
1204	if (!in_ia32_syscall())
1205		return x32_arch_ptrace(child, request, caddr, cdata);
1206#endif
1207#ifdef CONFIG_IA32_EMULATION
1208	return ia32_arch_ptrace(child, request, caddr, cdata);
1209#else
1210	return 0;
1211#endif
1212}
1213#endif	/* CONFIG_COMPAT */
1214
1215#ifdef CONFIG_X86_64
1216
1217static struct user_regset x86_64_regsets[] __ro_after_init = {
1218	[REGSET_GENERAL] = {
1219		.core_note_type = NT_PRSTATUS,
1220		.n = sizeof(struct user_regs_struct) / sizeof(long),
1221		.size = sizeof(long), .align = sizeof(long),
1222		.get = genregs_get, .set = genregs_set
1223	},
1224	[REGSET_FP] = {
1225		.core_note_type = NT_PRFPREG,
1226		.n = sizeof(struct user_i387_struct) / sizeof(long),
1227		.size = sizeof(long), .align = sizeof(long),
1228		.active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1229	},
1230	[REGSET_XSTATE] = {
1231		.core_note_type = NT_X86_XSTATE,
1232		.size = sizeof(u64), .align = sizeof(u64),
1233		.active = xstateregs_active, .get = xstateregs_get,
1234		.set = xstateregs_set
1235	},
1236	[REGSET_IOPERM64] = {
1237		.core_note_type = NT_386_IOPERM,
1238		.n = IO_BITMAP_LONGS,
1239		.size = sizeof(long), .align = sizeof(long),
1240		.active = ioperm_active, .get = ioperm_get
1241	},
1242};
1243
1244static const struct user_regset_view user_x86_64_view = {
1245	.name = "x86_64", .e_machine = EM_X86_64,
1246	.regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1247};
1248
1249#else  /* CONFIG_X86_32 */
1250
1251#define user_regs_struct32	user_regs_struct
1252#define genregs32_get		genregs_get
1253#define genregs32_set		genregs_set
1254
 
 
 
1255#endif	/* CONFIG_X86_64 */
1256
1257#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1258static struct user_regset x86_32_regsets[] __ro_after_init = {
1259	[REGSET_GENERAL] = {
1260		.core_note_type = NT_PRSTATUS,
1261		.n = sizeof(struct user_regs_struct32) / sizeof(u32),
1262		.size = sizeof(u32), .align = sizeof(u32),
1263		.get = genregs32_get, .set = genregs32_set
1264	},
1265	[REGSET_FP] = {
1266		.core_note_type = NT_PRFPREG,
1267		.n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1268		.size = sizeof(u32), .align = sizeof(u32),
1269		.active = regset_fpregs_active, .get = fpregs_get, .set = fpregs_set
1270	},
1271	[REGSET_XFP] = {
1272		.core_note_type = NT_PRXFPREG,
1273		.n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1274		.size = sizeof(u32), .align = sizeof(u32),
1275		.active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1276	},
1277	[REGSET_XSTATE] = {
1278		.core_note_type = NT_X86_XSTATE,
1279		.size = sizeof(u64), .align = sizeof(u64),
1280		.active = xstateregs_active, .get = xstateregs_get,
1281		.set = xstateregs_set
1282	},
1283	[REGSET_TLS] = {
1284		.core_note_type = NT_386_TLS,
1285		.n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1286		.size = sizeof(struct user_desc),
1287		.align = sizeof(struct user_desc),
1288		.active = regset_tls_active,
1289		.get = regset_tls_get, .set = regset_tls_set
1290	},
1291	[REGSET_IOPERM32] = {
1292		.core_note_type = NT_386_IOPERM,
1293		.n = IO_BITMAP_BYTES / sizeof(u32),
1294		.size = sizeof(u32), .align = sizeof(u32),
1295		.active = ioperm_active, .get = ioperm_get
1296	},
1297};
1298
1299static const struct user_regset_view user_x86_32_view = {
1300	.name = "i386", .e_machine = EM_386,
1301	.regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1302};
1303#endif
1304
1305/*
1306 * This represents bytes 464..511 in the memory layout exported through
1307 * the REGSET_XSTATE interface.
1308 */
1309u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1310
1311void __init update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1312{
1313#ifdef CONFIG_X86_64
1314	x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1315#endif
1316#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1317	x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1318#endif
1319	xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1320}
1321
1322const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1323{
1324#ifdef CONFIG_IA32_EMULATION
1325	if (!user_64bit_mode(task_pt_regs(task)))
1326#endif
1327#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1328		return &user_x86_32_view;
1329#endif
1330#ifdef CONFIG_X86_64
1331	return &user_x86_64_view;
1332#endif
1333}
1334
1335void send_sigtrap(struct pt_regs *regs, int error_code, int si_code)
 
 
 
1336{
1337	struct task_struct *tsk = current;
1338
1339	tsk->thread.trap_nr = X86_TRAP_DB;
1340	tsk->thread.error_code = error_code;
1341
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1342	/* Send us the fake SIGTRAP */
1343	force_sig_fault(SIGTRAP, si_code,
1344			user_mode(regs) ? (void __user *)regs->ip : NULL);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1345}
1346
1347void user_single_step_report(struct pt_regs *regs)
1348{
1349	send_sigtrap(regs, 0, TRAP_BRKPT);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1350}
v3.1
 
   1/* By Ross Biro 1/23/92 */
   2/*
   3 * Pentium III FXSR, SSE support
   4 *	Gareth Hughes <gareth@valinux.com>, May 2000
   5 */
   6
   7#include <linux/kernel.h>
   8#include <linux/sched.h>
 
   9#include <linux/mm.h>
  10#include <linux/smp.h>
  11#include <linux/errno.h>
  12#include <linux/slab.h>
  13#include <linux/ptrace.h>
  14#include <linux/regset.h>
  15#include <linux/tracehook.h>
  16#include <linux/user.h>
  17#include <linux/elf.h>
  18#include <linux/security.h>
  19#include <linux/audit.h>
  20#include <linux/seccomp.h>
  21#include <linux/signal.h>
  22#include <linux/perf_event.h>
  23#include <linux/hw_breakpoint.h>
 
 
 
 
  24
  25#include <asm/uaccess.h>
  26#include <asm/pgtable.h>
  27#include <asm/system.h>
  28#include <asm/processor.h>
  29#include <asm/i387.h>
 
 
  30#include <asm/debugreg.h>
  31#include <asm/ldt.h>
  32#include <asm/desc.h>
  33#include <asm/prctl.h>
  34#include <asm/proto.h>
  35#include <asm/hw_breakpoint.h>
 
 
 
  36
  37#include "tls.h"
  38
  39#define CREATE_TRACE_POINTS
  40#include <trace/events/syscalls.h>
  41
  42enum x86_regset {
  43	REGSET_GENERAL,
  44	REGSET_FP,
  45	REGSET_XFP,
  46	REGSET_IOPERM64 = REGSET_XFP,
  47	REGSET_XSTATE,
  48	REGSET_TLS,
  49	REGSET_IOPERM32,
  50};
  51
  52struct pt_regs_offset {
  53	const char *name;
  54	int offset;
  55};
  56
  57#define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
  58#define REG_OFFSET_END {.name = NULL, .offset = 0}
  59
  60static const struct pt_regs_offset regoffset_table[] = {
  61#ifdef CONFIG_X86_64
  62	REG_OFFSET_NAME(r15),
  63	REG_OFFSET_NAME(r14),
  64	REG_OFFSET_NAME(r13),
  65	REG_OFFSET_NAME(r12),
  66	REG_OFFSET_NAME(r11),
  67	REG_OFFSET_NAME(r10),
  68	REG_OFFSET_NAME(r9),
  69	REG_OFFSET_NAME(r8),
  70#endif
  71	REG_OFFSET_NAME(bx),
  72	REG_OFFSET_NAME(cx),
  73	REG_OFFSET_NAME(dx),
  74	REG_OFFSET_NAME(si),
  75	REG_OFFSET_NAME(di),
  76	REG_OFFSET_NAME(bp),
  77	REG_OFFSET_NAME(ax),
  78#ifdef CONFIG_X86_32
  79	REG_OFFSET_NAME(ds),
  80	REG_OFFSET_NAME(es),
  81	REG_OFFSET_NAME(fs),
  82	REG_OFFSET_NAME(gs),
  83#endif
  84	REG_OFFSET_NAME(orig_ax),
  85	REG_OFFSET_NAME(ip),
  86	REG_OFFSET_NAME(cs),
  87	REG_OFFSET_NAME(flags),
  88	REG_OFFSET_NAME(sp),
  89	REG_OFFSET_NAME(ss),
  90	REG_OFFSET_END,
  91};
  92
  93/**
  94 * regs_query_register_offset() - query register offset from its name
  95 * @name:	the name of a register
  96 *
  97 * regs_query_register_offset() returns the offset of a register in struct
  98 * pt_regs from its name. If the name is invalid, this returns -EINVAL;
  99 */
 100int regs_query_register_offset(const char *name)
 101{
 102	const struct pt_regs_offset *roff;
 103	for (roff = regoffset_table; roff->name != NULL; roff++)
 104		if (!strcmp(roff->name, name))
 105			return roff->offset;
 106	return -EINVAL;
 107}
 108
 109/**
 110 * regs_query_register_name() - query register name from its offset
 111 * @offset:	the offset of a register in struct pt_regs.
 112 *
 113 * regs_query_register_name() returns the name of a register from its
 114 * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
 115 */
 116const char *regs_query_register_name(unsigned int offset)
 117{
 118	const struct pt_regs_offset *roff;
 119	for (roff = regoffset_table; roff->name != NULL; roff++)
 120		if (roff->offset == offset)
 121			return roff->name;
 122	return NULL;
 123}
 124
 125static const int arg_offs_table[] = {
 126#ifdef CONFIG_X86_32
 127	[0] = offsetof(struct pt_regs, ax),
 128	[1] = offsetof(struct pt_regs, dx),
 129	[2] = offsetof(struct pt_regs, cx)
 130#else /* CONFIG_X86_64 */
 131	[0] = offsetof(struct pt_regs, di),
 132	[1] = offsetof(struct pt_regs, si),
 133	[2] = offsetof(struct pt_regs, dx),
 134	[3] = offsetof(struct pt_regs, cx),
 135	[4] = offsetof(struct pt_regs, r8),
 136	[5] = offsetof(struct pt_regs, r9)
 137#endif
 138};
 139
 140/*
 141 * does not yet catch signals sent when the child dies.
 142 * in exit.c or in signal.c.
 143 */
 144
 145/*
 146 * Determines which flags the user has access to [1 = access, 0 = no access].
 147 */
 148#define FLAG_MASK_32		((unsigned long)			\
 149				 (X86_EFLAGS_CF | X86_EFLAGS_PF |	\
 150				  X86_EFLAGS_AF | X86_EFLAGS_ZF |	\
 151				  X86_EFLAGS_SF | X86_EFLAGS_TF |	\
 152				  X86_EFLAGS_DF | X86_EFLAGS_OF |	\
 153				  X86_EFLAGS_RF | X86_EFLAGS_AC))
 154
 155/*
 156 * Determines whether a value may be installed in a segment register.
 157 */
 158static inline bool invalid_selector(u16 value)
 159{
 160	return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
 161}
 162
 163#ifdef CONFIG_X86_32
 164
 165#define FLAG_MASK		FLAG_MASK_32
 166
 167static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
 168{
 169	BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
 170	return &regs->bx + (regno >> 2);
 171}
 172
 173static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 174{
 175	/*
 176	 * Returning the value truncates it to 16 bits.
 177	 */
 178	unsigned int retval;
 179	if (offset != offsetof(struct user_regs_struct, gs))
 180		retval = *pt_regs_access(task_pt_regs(task), offset);
 181	else {
 182		if (task == current)
 183			retval = get_user_gs(task_pt_regs(task));
 184		else
 185			retval = task_user_gs(task);
 186	}
 187	return retval;
 188}
 189
 190static int set_segment_reg(struct task_struct *task,
 191			   unsigned long offset, u16 value)
 192{
 193	/*
 194	 * The value argument was already truncated to 16 bits.
 195	 */
 196	if (invalid_selector(value))
 197		return -EIO;
 198
 199	/*
 200	 * For %cs and %ss we cannot permit a null selector.
 201	 * We can permit a bogus selector as long as it has USER_RPL.
 202	 * Null selectors are fine for other segment registers, but
 203	 * we will never get back to user mode with invalid %cs or %ss
 204	 * and will take the trap in iret instead.  Much code relies
 205	 * on user_mode() to distinguish a user trap frame (which can
 206	 * safely use invalid selectors) from a kernel trap frame.
 207	 */
 208	switch (offset) {
 209	case offsetof(struct user_regs_struct, cs):
 210	case offsetof(struct user_regs_struct, ss):
 211		if (unlikely(value == 0))
 212			return -EIO;
 
 213
 214	default:
 215		*pt_regs_access(task_pt_regs(task), offset) = value;
 216		break;
 217
 218	case offsetof(struct user_regs_struct, gs):
 219		if (task == current)
 220			set_user_gs(task_pt_regs(task), value);
 221		else
 222			task_user_gs(task) = value;
 223	}
 224
 225	return 0;
 226}
 227
 228#else  /* CONFIG_X86_64 */
 229
 230#define FLAG_MASK		(FLAG_MASK_32 | X86_EFLAGS_NT)
 231
 232static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
 233{
 234	BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
 235	return &regs->r15 + (offset / sizeof(regs->r15));
 236}
 237
 238static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 239{
 240	/*
 241	 * Returning the value truncates it to 16 bits.
 242	 */
 243	unsigned int seg;
 244
 245	switch (offset) {
 246	case offsetof(struct user_regs_struct, fs):
 247		if (task == current) {
 248			/* Older gas can't assemble movq %?s,%r?? */
 249			asm("movl %%fs,%0" : "=r" (seg));
 250			return seg;
 251		}
 252		return task->thread.fsindex;
 253	case offsetof(struct user_regs_struct, gs):
 254		if (task == current) {
 255			asm("movl %%gs,%0" : "=r" (seg));
 256			return seg;
 257		}
 258		return task->thread.gsindex;
 259	case offsetof(struct user_regs_struct, ds):
 260		if (task == current) {
 261			asm("movl %%ds,%0" : "=r" (seg));
 262			return seg;
 263		}
 264		return task->thread.ds;
 265	case offsetof(struct user_regs_struct, es):
 266		if (task == current) {
 267			asm("movl %%es,%0" : "=r" (seg));
 268			return seg;
 269		}
 270		return task->thread.es;
 271
 272	case offsetof(struct user_regs_struct, cs):
 273	case offsetof(struct user_regs_struct, ss):
 274		break;
 275	}
 276	return *pt_regs_access(task_pt_regs(task), offset);
 277}
 278
 279static int set_segment_reg(struct task_struct *task,
 280			   unsigned long offset, u16 value)
 281{
 282	/*
 283	 * The value argument was already truncated to 16 bits.
 284	 */
 285	if (invalid_selector(value))
 286		return -EIO;
 287
 288	switch (offset) {
 289	case offsetof(struct user_regs_struct,fs):
 290		/*
 291		 * If this is setting fs as for normal 64-bit use but
 292		 * setting fs_base has implicitly changed it, leave it.
 293		 */
 294		if ((value == FS_TLS_SEL && task->thread.fsindex == 0 &&
 295		     task->thread.fs != 0) ||
 296		    (value == 0 && task->thread.fsindex == FS_TLS_SEL &&
 297		     task->thread.fs == 0))
 298			break;
 299		task->thread.fsindex = value;
 300		if (task == current)
 301			loadsegment(fs, task->thread.fsindex);
 302		break;
 303	case offsetof(struct user_regs_struct,gs):
 304		/*
 305		 * If this is setting gs as for normal 64-bit use but
 306		 * setting gs_base has implicitly changed it, leave it.
 307		 */
 308		if ((value == GS_TLS_SEL && task->thread.gsindex == 0 &&
 309		     task->thread.gs != 0) ||
 310		    (value == 0 && task->thread.gsindex == GS_TLS_SEL &&
 311		     task->thread.gs == 0))
 312			break;
 313		task->thread.gsindex = value;
 314		if (task == current)
 315			load_gs_index(task->thread.gsindex);
 316		break;
 317	case offsetof(struct user_regs_struct,ds):
 318		task->thread.ds = value;
 319		if (task == current)
 320			loadsegment(ds, task->thread.ds);
 321		break;
 322	case offsetof(struct user_regs_struct,es):
 323		task->thread.es = value;
 324		if (task == current)
 325			loadsegment(es, task->thread.es);
 326		break;
 327
 328		/*
 329		 * Can't actually change these in 64-bit mode.
 330		 */
 331	case offsetof(struct user_regs_struct,cs):
 332		if (unlikely(value == 0))
 333			return -EIO;
 334#ifdef CONFIG_IA32_EMULATION
 335		if (test_tsk_thread_flag(task, TIF_IA32))
 336			task_pt_regs(task)->cs = value;
 337#endif
 338		break;
 339	case offsetof(struct user_regs_struct,ss):
 340		if (unlikely(value == 0))
 341			return -EIO;
 342#ifdef CONFIG_IA32_EMULATION
 343		if (test_tsk_thread_flag(task, TIF_IA32))
 344			task_pt_regs(task)->ss = value;
 345#endif
 346		break;
 347	}
 348
 349	return 0;
 350}
 351
 352#endif	/* CONFIG_X86_32 */
 353
 354static unsigned long get_flags(struct task_struct *task)
 355{
 356	unsigned long retval = task_pt_regs(task)->flags;
 357
 358	/*
 359	 * If the debugger set TF, hide it from the readout.
 360	 */
 361	if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 362		retval &= ~X86_EFLAGS_TF;
 363
 364	return retval;
 365}
 366
 367static int set_flags(struct task_struct *task, unsigned long value)
 368{
 369	struct pt_regs *regs = task_pt_regs(task);
 370
 371	/*
 372	 * If the user value contains TF, mark that
 373	 * it was not "us" (the debugger) that set it.
 374	 * If not, make sure it stays set if we had.
 375	 */
 376	if (value & X86_EFLAGS_TF)
 377		clear_tsk_thread_flag(task, TIF_FORCED_TF);
 378	else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 379		value |= X86_EFLAGS_TF;
 380
 381	regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
 382
 383	return 0;
 384}
 385
 386static int putreg(struct task_struct *child,
 387		  unsigned long offset, unsigned long value)
 388{
 389	switch (offset) {
 390	case offsetof(struct user_regs_struct, cs):
 391	case offsetof(struct user_regs_struct, ds):
 392	case offsetof(struct user_regs_struct, es):
 393	case offsetof(struct user_regs_struct, fs):
 394	case offsetof(struct user_regs_struct, gs):
 395	case offsetof(struct user_regs_struct, ss):
 396		return set_segment_reg(child, offset, value);
 397
 398	case offsetof(struct user_regs_struct, flags):
 399		return set_flags(child, value);
 400
 401#ifdef CONFIG_X86_64
 402	case offsetof(struct user_regs_struct,fs_base):
 403		if (value >= TASK_SIZE_OF(child))
 404			return -EIO;
 405		/*
 406		 * When changing the segment base, use do_arch_prctl
 407		 * to set either thread.fs or thread.fsindex and the
 408		 * corresponding GDT slot.
 409		 */
 410		if (child->thread.fs != value)
 411			return do_arch_prctl(child, ARCH_SET_FS, value);
 412		return 0;
 413	case offsetof(struct user_regs_struct,gs_base):
 414		/*
 415		 * Exactly the same here as the %fs handling above.
 416		 */
 417		if (value >= TASK_SIZE_OF(child))
 418			return -EIO;
 419		if (child->thread.gs != value)
 420			return do_arch_prctl(child, ARCH_SET_GS, value);
 421		return 0;
 422#endif
 423	}
 424
 425	*pt_regs_access(task_pt_regs(child), offset) = value;
 426	return 0;
 427}
 428
 429static unsigned long getreg(struct task_struct *task, unsigned long offset)
 430{
 431	switch (offset) {
 432	case offsetof(struct user_regs_struct, cs):
 433	case offsetof(struct user_regs_struct, ds):
 434	case offsetof(struct user_regs_struct, es):
 435	case offsetof(struct user_regs_struct, fs):
 436	case offsetof(struct user_regs_struct, gs):
 437	case offsetof(struct user_regs_struct, ss):
 438		return get_segment_reg(task, offset);
 439
 440	case offsetof(struct user_regs_struct, flags):
 441		return get_flags(task);
 442
 443#ifdef CONFIG_X86_64
 444	case offsetof(struct user_regs_struct, fs_base): {
 445		/*
 446		 * do_arch_prctl may have used a GDT slot instead of
 447		 * the MSR.  To userland, it appears the same either
 448		 * way, except the %fs segment selector might not be 0.
 449		 */
 450		unsigned int seg = task->thread.fsindex;
 451		if (task->thread.fs != 0)
 452			return task->thread.fs;
 453		if (task == current)
 454			asm("movl %%fs,%0" : "=r" (seg));
 455		if (seg != FS_TLS_SEL)
 456			return 0;
 457		return get_desc_base(&task->thread.tls_array[FS_TLS]);
 458	}
 459	case offsetof(struct user_regs_struct, gs_base): {
 460		/*
 461		 * Exactly the same here as the %fs handling above.
 462		 */
 463		unsigned int seg = task->thread.gsindex;
 464		if (task->thread.gs != 0)
 465			return task->thread.gs;
 466		if (task == current)
 467			asm("movl %%gs,%0" : "=r" (seg));
 468		if (seg != GS_TLS_SEL)
 469			return 0;
 470		return get_desc_base(&task->thread.tls_array[GS_TLS]);
 471	}
 472#endif
 473	}
 474
 475	return *pt_regs_access(task_pt_regs(task), offset);
 476}
 477
 478static int genregs_get(struct task_struct *target,
 479		       const struct user_regset *regset,
 480		       unsigned int pos, unsigned int count,
 481		       void *kbuf, void __user *ubuf)
 482{
 483	if (kbuf) {
 484		unsigned long *k = kbuf;
 485		while (count >= sizeof(*k)) {
 486			*k++ = getreg(target, pos);
 487			count -= sizeof(*k);
 488			pos += sizeof(*k);
 489		}
 490	} else {
 491		unsigned long __user *u = ubuf;
 492		while (count >= sizeof(*u)) {
 493			if (__put_user(getreg(target, pos), u++))
 494				return -EFAULT;
 495			count -= sizeof(*u);
 496			pos += sizeof(*u);
 497		}
 498	}
 499
 500	return 0;
 501}
 502
 503static int genregs_set(struct task_struct *target,
 504		       const struct user_regset *regset,
 505		       unsigned int pos, unsigned int count,
 506		       const void *kbuf, const void __user *ubuf)
 507{
 508	int ret = 0;
 509	if (kbuf) {
 510		const unsigned long *k = kbuf;
 511		while (count >= sizeof(*k) && !ret) {
 512			ret = putreg(target, pos, *k++);
 513			count -= sizeof(*k);
 514			pos += sizeof(*k);
 515		}
 516	} else {
 517		const unsigned long  __user *u = ubuf;
 518		while (count >= sizeof(*u) && !ret) {
 519			unsigned long word;
 520			ret = __get_user(word, u++);
 521			if (ret)
 522				break;
 523			ret = putreg(target, pos, word);
 524			count -= sizeof(*u);
 525			pos += sizeof(*u);
 526		}
 527	}
 528	return ret;
 529}
 530
 531static void ptrace_triggered(struct perf_event *bp,
 532			     struct perf_sample_data *data,
 533			     struct pt_regs *regs)
 534{
 535	int i;
 536	struct thread_struct *thread = &(current->thread);
 537
 538	/*
 539	 * Store in the virtual DR6 register the fact that the breakpoint
 540	 * was hit so the thread's debugger will see it.
 541	 */
 542	for (i = 0; i < HBP_NUM; i++) {
 543		if (thread->ptrace_bps[i] == bp)
 544			break;
 545	}
 546
 547	thread->debugreg6 |= (DR_TRAP0 << i);
 548}
 549
 550/*
 551 * Walk through every ptrace breakpoints for this thread and
 552 * build the dr7 value on top of their attributes.
 553 *
 554 */
 555static unsigned long ptrace_get_dr7(struct perf_event *bp[])
 556{
 557	int i;
 558	int dr7 = 0;
 559	struct arch_hw_breakpoint *info;
 560
 561	for (i = 0; i < HBP_NUM; i++) {
 562		if (bp[i] && !bp[i]->attr.disabled) {
 563			info = counter_arch_bp(bp[i]);
 564			dr7 |= encode_dr7(i, info->len, info->type);
 565		}
 566	}
 567
 568	return dr7;
 569}
 570
 571static int
 572ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
 573			 struct task_struct *tsk, int disabled)
 574{
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 575	int err;
 576	int gen_len, gen_type;
 577	struct perf_event_attr attr;
 578
 579	/*
 580	 * We should have at least an inactive breakpoint at this
 581	 * slot. It means the user is writing dr7 without having
 582	 * written the address register first
 583	 */
 584	if (!bp)
 585		return -EINVAL;
 
 
 
 
 
 
 
 
 
 586
 587	err = arch_bp_generic_fields(len, type, &gen_len, &gen_type);
 588	if (err)
 589		return err;
 590
 591	attr = bp->attr;
 592	attr.bp_len = gen_len;
 593	attr.bp_type = gen_type;
 594	attr.disabled = disabled;
 595
 596	return modify_user_hw_breakpoint(bp, &attr);
 597}
 598
 599/*
 600 * Handle ptrace writes to debug register 7.
 601 */
 602static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
 603{
 604	struct thread_struct *thread = &(tsk->thread);
 605	unsigned long old_dr7;
 606	int i, orig_ret = 0, rc = 0;
 607	int enabled, second_pass = 0;
 608	unsigned len, type;
 609	struct perf_event *bp;
 610
 611	if (ptrace_get_breakpoints(tsk) < 0)
 612		return -ESRCH;
 613
 614	data &= ~DR_CONTROL_RESERVED;
 615	old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
 
 616restore:
 617	/*
 618	 * Loop through all the hardware breakpoints, making the
 619	 * appropriate changes to each.
 620	 */
 621	for (i = 0; i < HBP_NUM; i++) {
 622		enabled = decode_dr7(data, i, &len, &type);
 623		bp = thread->ptrace_bps[i];
 
 
 
 
 
 
 
 
 
 
 
 
 624
 625		if (!enabled) {
 626			if (bp) {
 627				/*
 628				 * Don't unregister the breakpoints right-away,
 629				 * unless all register_user_hw_breakpoint()
 630				 * requests have succeeded. This prevents
 631				 * any window of opportunity for debug
 632				 * register grabbing by other users.
 633				 */
 634				if (!second_pass)
 635					continue;
 636
 637				rc = ptrace_modify_breakpoint(bp, len, type,
 638							      tsk, 1);
 639				if (rc)
 640					break;
 641			}
 642			continue;
 643		}
 644
 645		rc = ptrace_modify_breakpoint(bp, len, type, tsk, 0);
 646		if (rc)
 647			break;
 648	}
 649	/*
 650	 * Make a second pass to free the remaining unused breakpoints
 651	 * or to restore the original breakpoints if an error occurred.
 652	 */
 653	if (!second_pass) {
 654		second_pass = 1;
 655		if (rc < 0) {
 656			orig_ret = rc;
 657			data = old_dr7;
 658		}
 659		goto restore;
 660	}
 661
 662	ptrace_put_breakpoints(tsk);
 663
 664	return ((orig_ret < 0) ? orig_ret : rc);
 665}
 666
 667/*
 668 * Handle PTRACE_PEEKUSR calls for the debug register area.
 669 */
 670static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
 671{
 672	struct thread_struct *thread = &(tsk->thread);
 673	unsigned long val = 0;
 674
 675	if (n < HBP_NUM) {
 676		struct perf_event *bp;
 677
 678		if (ptrace_get_breakpoints(tsk) < 0)
 679			return -ESRCH;
 680
 681		bp = thread->ptrace_bps[n];
 682		if (!bp)
 683			val = 0;
 684		else
 685			val = bp->hw.info.address;
 686
 687		ptrace_put_breakpoints(tsk);
 688	} else if (n == 6) {
 689		val = thread->debugreg6;
 690	 } else if (n == 7) {
 691		val = thread->ptrace_dr7;
 692	}
 693	return val;
 694}
 695
 696static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
 697				      unsigned long addr)
 698{
 699	struct perf_event *bp;
 700	struct thread_struct *t = &tsk->thread;
 701	struct perf_event_attr attr;
 702	int err = 0;
 703
 704	if (ptrace_get_breakpoints(tsk) < 0)
 705		return -ESRCH;
 706
 707	if (!t->ptrace_bps[nr]) {
 708		ptrace_breakpoint_init(&attr);
 709		/*
 710		 * Put stub len and type to register (reserve) an inactive but
 711		 * correct bp
 712		 */
 713		attr.bp_addr = addr;
 714		attr.bp_len = HW_BREAKPOINT_LEN_1;
 715		attr.bp_type = HW_BREAKPOINT_W;
 716		attr.disabled = 1;
 717
 718		bp = register_user_hw_breakpoint(&attr, ptrace_triggered,
 719						 NULL, tsk);
 720
 721		/*
 
 
 722		 * CHECKME: the previous code returned -EIO if the addr wasn't
 723		 * a valid task virtual addr. The new one will return -EINVAL in
 724		 *  this case.
 725		 * -EINVAL may be what we want for in-kernel breakpoints users,
 726		 * but -EIO looks better for ptrace, since we refuse a register
 727		 * writing for the user. And anyway this is the previous
 728		 * behaviour.
 729		 */
 730		if (IS_ERR(bp)) {
 
 
 
 731			err = PTR_ERR(bp);
 732			goto put;
 733		}
 734
 735		t->ptrace_bps[nr] = bp;
 736	} else {
 737		bp = t->ptrace_bps[nr];
 738
 739		attr = bp->attr;
 740		attr.bp_addr = addr;
 741		err = modify_user_hw_breakpoint(bp, &attr);
 742	}
 743
 744put:
 745	ptrace_put_breakpoints(tsk);
 746	return err;
 747}
 748
 749/*
 750 * Handle PTRACE_POKEUSR calls for the debug register area.
 751 */
 752int ptrace_set_debugreg(struct task_struct *tsk, int n, unsigned long val)
 
 753{
 754	struct thread_struct *thread = &(tsk->thread);
 755	int rc = 0;
 756
 757	/* There are no DR4 or DR5 registers */
 758	if (n == 4 || n == 5)
 759		return -EIO;
 760
 761	if (n == 6) {
 762		thread->debugreg6 = val;
 763		goto ret_path;
 764	}
 765	if (n < HBP_NUM) {
 766		rc = ptrace_set_breakpoint_addr(tsk, n, val);
 767		if (rc)
 768			return rc;
 769	}
 770	/* All that's left is DR7 */
 771	if (n == 7) {
 772		rc = ptrace_write_dr7(tsk, val);
 773		if (!rc)
 774			thread->ptrace_dr7 = val;
 775	}
 776
 777ret_path:
 778	return rc;
 779}
 780
 781/*
 782 * These access the current or another (stopped) task's io permission
 783 * bitmap for debugging or core dump.
 784 */
 785static int ioperm_active(struct task_struct *target,
 786			 const struct user_regset *regset)
 787{
 788	return target->thread.io_bitmap_max / regset->size;
 789}
 790
 791static int ioperm_get(struct task_struct *target,
 792		      const struct user_regset *regset,
 793		      unsigned int pos, unsigned int count,
 794		      void *kbuf, void __user *ubuf)
 795{
 796	if (!target->thread.io_bitmap_ptr)
 797		return -ENXIO;
 798
 799	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 800				   target->thread.io_bitmap_ptr,
 801				   0, IO_BITMAP_BYTES);
 802}
 803
 804/*
 805 * Called by kernel/ptrace.c when detaching..
 806 *
 807 * Make sure the single step bit is not set.
 808 */
 809void ptrace_disable(struct task_struct *child)
 810{
 811	user_disable_single_step(child);
 812#ifdef TIF_SYSCALL_EMU
 813	clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
 814#endif
 815}
 816
 817#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 818static const struct user_regset_view user_x86_32_view; /* Initialized below. */
 819#endif
 820
 821long arch_ptrace(struct task_struct *child, long request,
 822		 unsigned long addr, unsigned long data)
 823{
 824	int ret;
 825	unsigned long __user *datap = (unsigned long __user *)data;
 826
 827	switch (request) {
 828	/* read the word at location addr in the USER area. */
 829	case PTRACE_PEEKUSR: {
 830		unsigned long tmp;
 831
 832		ret = -EIO;
 833		if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 834			break;
 835
 836		tmp = 0;  /* Default return condition */
 837		if (addr < sizeof(struct user_regs_struct))
 838			tmp = getreg(child, addr);
 839		else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 840			 addr <= offsetof(struct user, u_debugreg[7])) {
 841			addr -= offsetof(struct user, u_debugreg[0]);
 842			tmp = ptrace_get_debugreg(child, addr / sizeof(data));
 843		}
 844		ret = put_user(tmp, datap);
 845		break;
 846	}
 847
 848	case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
 849		ret = -EIO;
 850		if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 851			break;
 852
 853		if (addr < sizeof(struct user_regs_struct))
 854			ret = putreg(child, addr, data);
 855		else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 856			 addr <= offsetof(struct user, u_debugreg[7])) {
 857			addr -= offsetof(struct user, u_debugreg[0]);
 858			ret = ptrace_set_debugreg(child,
 859						  addr / sizeof(data), data);
 860		}
 861		break;
 862
 863	case PTRACE_GETREGS:	/* Get all gp regs from the child. */
 864		return copy_regset_to_user(child,
 865					   task_user_regset_view(current),
 866					   REGSET_GENERAL,
 867					   0, sizeof(struct user_regs_struct),
 868					   datap);
 869
 870	case PTRACE_SETREGS:	/* Set all gp regs in the child. */
 871		return copy_regset_from_user(child,
 872					     task_user_regset_view(current),
 873					     REGSET_GENERAL,
 874					     0, sizeof(struct user_regs_struct),
 875					     datap);
 876
 877	case PTRACE_GETFPREGS:	/* Get the child FPU state. */
 878		return copy_regset_to_user(child,
 879					   task_user_regset_view(current),
 880					   REGSET_FP,
 881					   0, sizeof(struct user_i387_struct),
 882					   datap);
 883
 884	case PTRACE_SETFPREGS:	/* Set the child FPU state. */
 885		return copy_regset_from_user(child,
 886					     task_user_regset_view(current),
 887					     REGSET_FP,
 888					     0, sizeof(struct user_i387_struct),
 889					     datap);
 890
 891#ifdef CONFIG_X86_32
 892	case PTRACE_GETFPXREGS:	/* Get the child extended FPU state. */
 893		return copy_regset_to_user(child, &user_x86_32_view,
 894					   REGSET_XFP,
 895					   0, sizeof(struct user_fxsr_struct),
 896					   datap) ? -EIO : 0;
 897
 898	case PTRACE_SETFPXREGS:	/* Set the child extended FPU state. */
 899		return copy_regset_from_user(child, &user_x86_32_view,
 900					     REGSET_XFP,
 901					     0, sizeof(struct user_fxsr_struct),
 902					     datap) ? -EIO : 0;
 903#endif
 904
 905#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 906	case PTRACE_GET_THREAD_AREA:
 907		if ((int) addr < 0)
 908			return -EIO;
 909		ret = do_get_thread_area(child, addr,
 910					(struct user_desc __user *)data);
 911		break;
 912
 913	case PTRACE_SET_THREAD_AREA:
 914		if ((int) addr < 0)
 915			return -EIO;
 916		ret = do_set_thread_area(child, addr,
 917					(struct user_desc __user *)data, 0);
 918		break;
 919#endif
 920
 921#ifdef CONFIG_X86_64
 922		/* normal 64bit interface to access TLS data.
 923		   Works just like arch_prctl, except that the arguments
 924		   are reversed. */
 925	case PTRACE_ARCH_PRCTL:
 926		ret = do_arch_prctl(child, data, addr);
 927		break;
 928#endif
 929
 930	default:
 931		ret = ptrace_request(child, request, addr, data);
 932		break;
 933	}
 934
 935	return ret;
 936}
 937
 938#ifdef CONFIG_IA32_EMULATION
 939
 940#include <linux/compat.h>
 941#include <linux/syscalls.h>
 942#include <asm/ia32.h>
 943#include <asm/user32.h>
 944
 945#define R32(l,q)							\
 946	case offsetof(struct user32, regs.l):				\
 947		regs->q = value; break
 948
 949#define SEG32(rs)							\
 950	case offsetof(struct user32, regs.rs):				\
 951		return set_segment_reg(child,				\
 952				       offsetof(struct user_regs_struct, rs), \
 953				       value);				\
 954		break
 955
 956static int putreg32(struct task_struct *child, unsigned regno, u32 value)
 957{
 958	struct pt_regs *regs = task_pt_regs(child);
 959
 960	switch (regno) {
 961
 962	SEG32(cs);
 963	SEG32(ds);
 964	SEG32(es);
 965	SEG32(fs);
 966	SEG32(gs);
 967	SEG32(ss);
 968
 969	R32(ebx, bx);
 970	R32(ecx, cx);
 971	R32(edx, dx);
 972	R32(edi, di);
 973	R32(esi, si);
 974	R32(ebp, bp);
 975	R32(eax, ax);
 976	R32(eip, ip);
 977	R32(esp, sp);
 978
 979	case offsetof(struct user32, regs.orig_eax):
 980		/*
 981		 * A 32-bit debugger setting orig_eax means to restore
 982		 * the state of the task restarting a 32-bit syscall.
 983		 * Make sure we interpret the -ERESTART* codes correctly
 984		 * in case the task is not actually still sitting at the
 985		 * exit from a 32-bit syscall with TS_COMPAT still set.
 
 
 
 986		 */
 987		regs->orig_ax = value;
 988		if (syscall_get_nr(child, regs) >= 0)
 989			task_thread_info(child)->status |= TS_COMPAT;
 990		break;
 991
 992	case offsetof(struct user32, regs.eflags):
 993		return set_flags(child, value);
 994
 995	case offsetof(struct user32, u_debugreg[0]) ...
 996		offsetof(struct user32, u_debugreg[7]):
 997		regno -= offsetof(struct user32, u_debugreg[0]);
 998		return ptrace_set_debugreg(child, regno / 4, value);
 999
1000	default:
1001		if (regno > sizeof(struct user32) || (regno & 3))
1002			return -EIO;
1003
1004		/*
1005		 * Other dummy fields in the virtual user structure
1006		 * are ignored
1007		 */
1008		break;
1009	}
1010	return 0;
1011}
1012
1013#undef R32
1014#undef SEG32
1015
1016#define R32(l,q)							\
1017	case offsetof(struct user32, regs.l):				\
1018		*val = regs->q; break
1019
1020#define SEG32(rs)							\
1021	case offsetof(struct user32, regs.rs):				\
1022		*val = get_segment_reg(child,				\
1023				       offsetof(struct user_regs_struct, rs)); \
1024		break
1025
1026static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
1027{
1028	struct pt_regs *regs = task_pt_regs(child);
1029
1030	switch (regno) {
1031
1032	SEG32(ds);
1033	SEG32(es);
1034	SEG32(fs);
1035	SEG32(gs);
1036
1037	R32(cs, cs);
1038	R32(ss, ss);
1039	R32(ebx, bx);
1040	R32(ecx, cx);
1041	R32(edx, dx);
1042	R32(edi, di);
1043	R32(esi, si);
1044	R32(ebp, bp);
1045	R32(eax, ax);
1046	R32(orig_eax, orig_ax);
1047	R32(eip, ip);
1048	R32(esp, sp);
1049
1050	case offsetof(struct user32, regs.eflags):
1051		*val = get_flags(child);
1052		break;
1053
1054	case offsetof(struct user32, u_debugreg[0]) ...
1055		offsetof(struct user32, u_debugreg[7]):
1056		regno -= offsetof(struct user32, u_debugreg[0]);
1057		*val = ptrace_get_debugreg(child, regno / 4);
1058		break;
1059
1060	default:
1061		if (regno > sizeof(struct user32) || (regno & 3))
1062			return -EIO;
1063
1064		/*
1065		 * Other dummy fields in the virtual user structure
1066		 * are ignored
1067		 */
1068		*val = 0;
1069		break;
1070	}
1071	return 0;
1072}
1073
1074#undef R32
1075#undef SEG32
1076
1077static int genregs32_get(struct task_struct *target,
1078			 const struct user_regset *regset,
1079			 unsigned int pos, unsigned int count,
1080			 void *kbuf, void __user *ubuf)
1081{
1082	if (kbuf) {
1083		compat_ulong_t *k = kbuf;
1084		while (count >= sizeof(*k)) {
1085			getreg32(target, pos, k++);
1086			count -= sizeof(*k);
1087			pos += sizeof(*k);
1088		}
1089	} else {
1090		compat_ulong_t __user *u = ubuf;
1091		while (count >= sizeof(*u)) {
1092			compat_ulong_t word;
1093			getreg32(target, pos, &word);
1094			if (__put_user(word, u++))
1095				return -EFAULT;
1096			count -= sizeof(*u);
1097			pos += sizeof(*u);
1098		}
1099	}
1100
1101	return 0;
1102}
1103
1104static int genregs32_set(struct task_struct *target,
1105			 const struct user_regset *regset,
1106			 unsigned int pos, unsigned int count,
1107			 const void *kbuf, const void __user *ubuf)
1108{
1109	int ret = 0;
1110	if (kbuf) {
1111		const compat_ulong_t *k = kbuf;
1112		while (count >= sizeof(*k) && !ret) {
1113			ret = putreg32(target, pos, *k++);
1114			count -= sizeof(*k);
1115			pos += sizeof(*k);
1116		}
1117	} else {
1118		const compat_ulong_t __user *u = ubuf;
1119		while (count >= sizeof(*u) && !ret) {
1120			compat_ulong_t word;
1121			ret = __get_user(word, u++);
1122			if (ret)
1123				break;
1124			ret = putreg32(target, pos, word);
1125			count -= sizeof(*u);
1126			pos += sizeof(*u);
1127		}
1128	}
1129	return ret;
1130}
1131
1132long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1133			compat_ulong_t caddr, compat_ulong_t cdata)
1134{
1135	unsigned long addr = caddr;
1136	unsigned long data = cdata;
1137	void __user *datap = compat_ptr(data);
1138	int ret;
1139	__u32 val;
1140
1141	switch (request) {
1142	case PTRACE_PEEKUSR:
1143		ret = getreg32(child, addr, &val);
1144		if (ret == 0)
1145			ret = put_user(val, (__u32 __user *)datap);
1146		break;
1147
1148	case PTRACE_POKEUSR:
1149		ret = putreg32(child, addr, data);
1150		break;
1151
1152	case PTRACE_GETREGS:	/* Get all gp regs from the child. */
1153		return copy_regset_to_user(child, &user_x86_32_view,
1154					   REGSET_GENERAL,
1155					   0, sizeof(struct user_regs_struct32),
1156					   datap);
1157
1158	case PTRACE_SETREGS:	/* Set all gp regs in the child. */
1159		return copy_regset_from_user(child, &user_x86_32_view,
1160					     REGSET_GENERAL, 0,
1161					     sizeof(struct user_regs_struct32),
1162					     datap);
1163
1164	case PTRACE_GETFPREGS:	/* Get the child FPU state. */
1165		return copy_regset_to_user(child, &user_x86_32_view,
1166					   REGSET_FP, 0,
1167					   sizeof(struct user_i387_ia32_struct),
1168					   datap);
1169
1170	case PTRACE_SETFPREGS:	/* Set the child FPU state. */
1171		return copy_regset_from_user(
1172			child, &user_x86_32_view, REGSET_FP,
1173			0, sizeof(struct user_i387_ia32_struct), datap);
1174
1175	case PTRACE_GETFPXREGS:	/* Get the child extended FPU state. */
1176		return copy_regset_to_user(child, &user_x86_32_view,
1177					   REGSET_XFP, 0,
1178					   sizeof(struct user32_fxsr_struct),
1179					   datap);
1180
1181	case PTRACE_SETFPXREGS:	/* Set the child extended FPU state. */
1182		return copy_regset_from_user(child, &user_x86_32_view,
1183					     REGSET_XFP, 0,
1184					     sizeof(struct user32_fxsr_struct),
1185					     datap);
1186
1187	case PTRACE_GET_THREAD_AREA:
1188	case PTRACE_SET_THREAD_AREA:
1189		return arch_ptrace(child, request, addr, data);
1190
1191	default:
1192		return compat_ptrace_request(child, request, addr, data);
1193	}
1194
1195	return ret;
1196}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1197
1198#endif	/* CONFIG_IA32_EMULATION */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1199
1200#ifdef CONFIG_X86_64
1201
1202static struct user_regset x86_64_regsets[] __read_mostly = {
1203	[REGSET_GENERAL] = {
1204		.core_note_type = NT_PRSTATUS,
1205		.n = sizeof(struct user_regs_struct) / sizeof(long),
1206		.size = sizeof(long), .align = sizeof(long),
1207		.get = genregs_get, .set = genregs_set
1208	},
1209	[REGSET_FP] = {
1210		.core_note_type = NT_PRFPREG,
1211		.n = sizeof(struct user_i387_struct) / sizeof(long),
1212		.size = sizeof(long), .align = sizeof(long),
1213		.active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1214	},
1215	[REGSET_XSTATE] = {
1216		.core_note_type = NT_X86_XSTATE,
1217		.size = sizeof(u64), .align = sizeof(u64),
1218		.active = xstateregs_active, .get = xstateregs_get,
1219		.set = xstateregs_set
1220	},
1221	[REGSET_IOPERM64] = {
1222		.core_note_type = NT_386_IOPERM,
1223		.n = IO_BITMAP_LONGS,
1224		.size = sizeof(long), .align = sizeof(long),
1225		.active = ioperm_active, .get = ioperm_get
1226	},
1227};
1228
1229static const struct user_regset_view user_x86_64_view = {
1230	.name = "x86_64", .e_machine = EM_X86_64,
1231	.regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1232};
1233
1234#else  /* CONFIG_X86_32 */
1235
1236#define user_regs_struct32	user_regs_struct
1237#define genregs32_get		genregs_get
1238#define genregs32_set		genregs_set
1239
1240#define user_i387_ia32_struct	user_i387_struct
1241#define user32_fxsr_struct	user_fxsr_struct
1242
1243#endif	/* CONFIG_X86_64 */
1244
1245#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1246static struct user_regset x86_32_regsets[] __read_mostly = {
1247	[REGSET_GENERAL] = {
1248		.core_note_type = NT_PRSTATUS,
1249		.n = sizeof(struct user_regs_struct32) / sizeof(u32),
1250		.size = sizeof(u32), .align = sizeof(u32),
1251		.get = genregs32_get, .set = genregs32_set
1252	},
1253	[REGSET_FP] = {
1254		.core_note_type = NT_PRFPREG,
1255		.n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1256		.size = sizeof(u32), .align = sizeof(u32),
1257		.active = fpregs_active, .get = fpregs_get, .set = fpregs_set
1258	},
1259	[REGSET_XFP] = {
1260		.core_note_type = NT_PRXFPREG,
1261		.n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1262		.size = sizeof(u32), .align = sizeof(u32),
1263		.active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1264	},
1265	[REGSET_XSTATE] = {
1266		.core_note_type = NT_X86_XSTATE,
1267		.size = sizeof(u64), .align = sizeof(u64),
1268		.active = xstateregs_active, .get = xstateregs_get,
1269		.set = xstateregs_set
1270	},
1271	[REGSET_TLS] = {
1272		.core_note_type = NT_386_TLS,
1273		.n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1274		.size = sizeof(struct user_desc),
1275		.align = sizeof(struct user_desc),
1276		.active = regset_tls_active,
1277		.get = regset_tls_get, .set = regset_tls_set
1278	},
1279	[REGSET_IOPERM32] = {
1280		.core_note_type = NT_386_IOPERM,
1281		.n = IO_BITMAP_BYTES / sizeof(u32),
1282		.size = sizeof(u32), .align = sizeof(u32),
1283		.active = ioperm_active, .get = ioperm_get
1284	},
1285};
1286
1287static const struct user_regset_view user_x86_32_view = {
1288	.name = "i386", .e_machine = EM_386,
1289	.regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1290};
1291#endif
1292
1293/*
1294 * This represents bytes 464..511 in the memory layout exported through
1295 * the REGSET_XSTATE interface.
1296 */
1297u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1298
1299void update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1300{
1301#ifdef CONFIG_X86_64
1302	x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1303#endif
1304#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1305	x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1306#endif
1307	xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1308}
1309
1310const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1311{
1312#ifdef CONFIG_IA32_EMULATION
1313	if (test_tsk_thread_flag(task, TIF_IA32))
1314#endif
1315#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1316		return &user_x86_32_view;
1317#endif
1318#ifdef CONFIG_X86_64
1319	return &user_x86_64_view;
1320#endif
1321}
1322
1323static void fill_sigtrap_info(struct task_struct *tsk,
1324				struct pt_regs *regs,
1325				int error_code, int si_code,
1326				struct siginfo *info)
1327{
1328	tsk->thread.trap_no = 1;
 
 
1329	tsk->thread.error_code = error_code;
1330
1331	memset(info, 0, sizeof(*info));
1332	info->si_signo = SIGTRAP;
1333	info->si_code = si_code;
1334	info->si_addr = user_mode_vm(regs) ? (void __user *)regs->ip : NULL;
1335}
1336
1337void user_single_step_siginfo(struct task_struct *tsk,
1338				struct pt_regs *regs,
1339				struct siginfo *info)
1340{
1341	fill_sigtrap_info(tsk, regs, 0, TRAP_BRKPT, info);
1342}
1343
1344void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
1345					 int error_code, int si_code)
1346{
1347	struct siginfo info;
1348
1349	fill_sigtrap_info(tsk, regs, error_code, si_code, &info);
1350	/* Send us the fake SIGTRAP */
1351	force_sig_info(SIGTRAP, &info, tsk);
1352}
1353
1354
1355#ifdef CONFIG_X86_32
1356# define IS_IA32	1
1357#elif defined CONFIG_IA32_EMULATION
1358# define IS_IA32	is_compat_task()
1359#else
1360# define IS_IA32	0
1361#endif
1362
1363/*
1364 * We must return the syscall number to actually look up in the table.
1365 * This can be -1L to skip running any syscall at all.
1366 */
1367long syscall_trace_enter(struct pt_regs *regs)
1368{
1369	long ret = 0;
1370
1371	/*
1372	 * If we stepped into a sysenter/syscall insn, it trapped in
1373	 * kernel mode; do_debug() cleared TF and set TIF_SINGLESTEP.
1374	 * If user-mode had set TF itself, then it's still clear from
1375	 * do_debug() and we need to set it again to restore the user
1376	 * state.  If we entered on the slow path, TF was already set.
1377	 */
1378	if (test_thread_flag(TIF_SINGLESTEP))
1379		regs->flags |= X86_EFLAGS_TF;
1380
1381	/* do the secure computing check first */
1382	secure_computing(regs->orig_ax);
1383
1384	if (unlikely(test_thread_flag(TIF_SYSCALL_EMU)))
1385		ret = -1L;
1386
1387	if ((ret || test_thread_flag(TIF_SYSCALL_TRACE)) &&
1388	    tracehook_report_syscall_entry(regs))
1389		ret = -1L;
1390
1391	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1392		trace_sys_enter(regs, regs->orig_ax);
1393
1394	if (unlikely(current->audit_context)) {
1395		if (IS_IA32)
1396			audit_syscall_entry(AUDIT_ARCH_I386,
1397					    regs->orig_ax,
1398					    regs->bx, regs->cx,
1399					    regs->dx, regs->si);
1400#ifdef CONFIG_X86_64
1401		else
1402			audit_syscall_entry(AUDIT_ARCH_X86_64,
1403					    regs->orig_ax,
1404					    regs->di, regs->si,
1405					    regs->dx, regs->r10);
1406#endif
1407	}
1408
1409	return ret ?: regs->orig_ax;
1410}
1411
1412void syscall_trace_leave(struct pt_regs *regs)
1413{
1414	bool step;
1415
1416	if (unlikely(current->audit_context))
1417		audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax);
1418
1419	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1420		trace_sys_exit(regs, regs->ax);
1421
1422	/*
1423	 * If TIF_SYSCALL_EMU is set, we only get here because of
1424	 * TIF_SINGLESTEP (i.e. this is PTRACE_SYSEMU_SINGLESTEP).
1425	 * We already reported this syscall instruction in
1426	 * syscall_trace_enter().
1427	 */
1428	step = unlikely(test_thread_flag(TIF_SINGLESTEP)) &&
1429			!test_thread_flag(TIF_SYSCALL_EMU);
1430	if (step || test_thread_flag(TIF_SYSCALL_TRACE))
1431		tracehook_report_syscall_exit(regs, step);
1432}