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v6.2
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 *  Ptrace user space interface.
   4 *
   5 *    Copyright IBM Corp. 1999, 2010
   6 *    Author(s): Denis Joseph Barrow
   7 *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   8 */
   9
  10#include "asm/ptrace.h"
  11#include <linux/kernel.h>
  12#include <linux/sched.h>
  13#include <linux/sched/task_stack.h>
  14#include <linux/mm.h>
  15#include <linux/smp.h>
  16#include <linux/errno.h>
  17#include <linux/ptrace.h>
  18#include <linux/user.h>
  19#include <linux/security.h>
  20#include <linux/audit.h>
  21#include <linux/signal.h>
  22#include <linux/elf.h>
  23#include <linux/regset.h>
  24#include <linux/seccomp.h>
  25#include <linux/compat.h>
  26#include <trace/syscall.h>
  27#include <asm/page.h>
  28#include <linux/uaccess.h>
  29#include <asm/unistd.h>
  30#include <asm/switch_to.h>
  31#include <asm/runtime_instr.h>
  32#include <asm/facility.h>
 
  33
  34#include "entry.h"
  35
  36#ifdef CONFIG_COMPAT
  37#include "compat_ptrace.h"
  38#endif
  39
  40void update_cr_regs(struct task_struct *task)
  41{
  42	struct pt_regs *regs = task_pt_regs(task);
  43	struct thread_struct *thread = &task->thread;
  44	struct per_regs old, new;
  45	union ctlreg0 cr0_old, cr0_new;
  46	union ctlreg2 cr2_old, cr2_new;
  47	int cr0_changed, cr2_changed;
 
 
 
 
 
 
 
 
  48
  49	__ctl_store(cr0_old.val, 0, 0);
  50	__ctl_store(cr2_old.val, 2, 2);
  51	cr0_new = cr0_old;
  52	cr2_new = cr2_old;
  53	/* Take care of the enable/disable of transactional execution. */
  54	if (MACHINE_HAS_TE) {
  55		/* Set or clear transaction execution TXC bit 8. */
  56		cr0_new.tcx = 1;
  57		if (task->thread.per_flags & PER_FLAG_NO_TE)
  58			cr0_new.tcx = 0;
  59		/* Set or clear transaction execution TDC bits 62 and 63. */
  60		cr2_new.tdc = 0;
  61		if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
  62			if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND_TEND)
  63				cr2_new.tdc = 1;
  64			else
  65				cr2_new.tdc = 2;
  66		}
  67	}
  68	/* Take care of enable/disable of guarded storage. */
  69	if (MACHINE_HAS_GS) {
  70		cr2_new.gse = 0;
  71		if (task->thread.gs_cb)
  72			cr2_new.gse = 1;
  73	}
  74	/* Load control register 0/2 iff changed */
  75	cr0_changed = cr0_new.val != cr0_old.val;
  76	cr2_changed = cr2_new.val != cr2_old.val;
  77	if (cr0_changed)
  78		__ctl_load(cr0_new.val, 0, 0);
  79	if (cr2_changed)
  80		__ctl_load(cr2_new.val, 2, 2);
  81	/* Copy user specified PER registers */
  82	new.control = thread->per_user.control;
  83	new.start = thread->per_user.start;
  84	new.end = thread->per_user.end;
  85
  86	/* merge TIF_SINGLE_STEP into user specified PER registers. */
  87	if (test_tsk_thread_flag(task, TIF_SINGLE_STEP) ||
  88	    test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP)) {
  89		if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))
  90			new.control |= PER_EVENT_BRANCH;
  91		else
  92			new.control |= PER_EVENT_IFETCH;
  93		new.control |= PER_CONTROL_SUSPENSION;
  94		new.control |= PER_EVENT_TRANSACTION_END;
  95		if (test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP))
  96			new.control |= PER_EVENT_IFETCH;
  97		new.start = 0;
  98		new.end = -1UL;
  99	}
 100
 101	/* Take care of the PER enablement bit in the PSW. */
 102	if (!(new.control & PER_EVENT_MASK)) {
 103		regs->psw.mask &= ~PSW_MASK_PER;
 104		return;
 105	}
 106	regs->psw.mask |= PSW_MASK_PER;
 107	__ctl_store(old, 9, 11);
 108	if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
 109		__ctl_load(new, 9, 11);
 110}
 111
 112void user_enable_single_step(struct task_struct *task)
 113{
 114	clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
 115	set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 116}
 117
 118void user_disable_single_step(struct task_struct *task)
 119{
 120	clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
 121	clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 122}
 123
 124void user_enable_block_step(struct task_struct *task)
 125{
 126	set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 127	set_tsk_thread_flag(task, TIF_BLOCK_STEP);
 128}
 129
 130/*
 131 * Called by kernel/ptrace.c when detaching..
 132 *
 133 * Clear all debugging related fields.
 134 */
 135void ptrace_disable(struct task_struct *task)
 136{
 137	memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
 138	memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
 139	clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 140	clear_tsk_thread_flag(task, TIF_PER_TRAP);
 141	task->thread.per_flags = 0;
 142}
 143
 144#define __ADDR_MASK 7
 145
 146static inline unsigned long __peek_user_per(struct task_struct *child,
 147					    addr_t addr)
 148{
 149	if (addr == offsetof(struct per_struct_kernel, cr9))
 150		/* Control bits of the active per set. */
 151		return test_thread_flag(TIF_SINGLE_STEP) ?
 152			PER_EVENT_IFETCH : child->thread.per_user.control;
 153	else if (addr == offsetof(struct per_struct_kernel, cr10))
 154		/* Start address of the active per set. */
 155		return test_thread_flag(TIF_SINGLE_STEP) ?
 156			0 : child->thread.per_user.start;
 157	else if (addr == offsetof(struct per_struct_kernel, cr11))
 158		/* End address of the active per set. */
 159		return test_thread_flag(TIF_SINGLE_STEP) ?
 160			-1UL : child->thread.per_user.end;
 161	else if (addr == offsetof(struct per_struct_kernel, bits))
 162		/* Single-step bit. */
 163		return test_thread_flag(TIF_SINGLE_STEP) ?
 164			(1UL << (BITS_PER_LONG - 1)) : 0;
 165	else if (addr == offsetof(struct per_struct_kernel, starting_addr))
 166		/* Start address of the user specified per set. */
 167		return child->thread.per_user.start;
 168	else if (addr == offsetof(struct per_struct_kernel, ending_addr))
 169		/* End address of the user specified per set. */
 170		return child->thread.per_user.end;
 171	else if (addr == offsetof(struct per_struct_kernel, perc_atmid))
 172		/* PER code, ATMID and AI of the last PER trap */
 173		return (unsigned long)
 174			child->thread.per_event.cause << (BITS_PER_LONG - 16);
 175	else if (addr == offsetof(struct per_struct_kernel, address))
 176		/* Address of the last PER trap */
 177		return child->thread.per_event.address;
 178	else if (addr == offsetof(struct per_struct_kernel, access_id))
 179		/* Access id of the last PER trap */
 180		return (unsigned long)
 181			child->thread.per_event.paid << (BITS_PER_LONG - 8);
 182	return 0;
 183}
 184
 185/*
 186 * Read the word at offset addr from the user area of a process. The
 187 * trouble here is that the information is littered over different
 188 * locations. The process registers are found on the kernel stack,
 189 * the floating point stuff and the trace settings are stored in
 190 * the task structure. In addition the different structures in
 191 * struct user contain pad bytes that should be read as zeroes.
 192 * Lovely...
 193 */
 194static unsigned long __peek_user(struct task_struct *child, addr_t addr)
 195{
 196	addr_t offset, tmp;
 197
 198	if (addr < offsetof(struct user, regs.acrs)) {
 199		/*
 200		 * psw and gprs are stored on the stack
 201		 */
 202		tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
 203		if (addr == offsetof(struct user, regs.psw.mask)) {
 204			/* Return a clean psw mask. */
 205			tmp &= PSW_MASK_USER | PSW_MASK_RI;
 206			tmp |= PSW_USER_BITS;
 207		}
 208
 209	} else if (addr < offsetof(struct user, regs.orig_gpr2)) {
 210		/*
 211		 * access registers are stored in the thread structure
 212		 */
 213		offset = addr - offsetof(struct user, regs.acrs);
 214		/*
 215		 * Very special case: old & broken 64 bit gdb reading
 216		 * from acrs[15]. Result is a 64 bit value. Read the
 217		 * 32 bit acrs[15] value and shift it by 32. Sick...
 218		 */
 219		if (addr == offsetof(struct user, regs.acrs[15]))
 220			tmp = ((unsigned long) child->thread.acrs[15]) << 32;
 221		else
 222			tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
 223
 224	} else if (addr == offsetof(struct user, regs.orig_gpr2)) {
 225		/*
 226		 * orig_gpr2 is stored on the kernel stack
 227		 */
 228		tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
 229
 230	} else if (addr < offsetof(struct user, regs.fp_regs)) {
 231		/*
 232		 * prevent reads of padding hole between
 233		 * orig_gpr2 and fp_regs on s390.
 234		 */
 235		tmp = 0;
 236
 237	} else if (addr == offsetof(struct user, regs.fp_regs.fpc)) {
 238		/*
 239		 * floating point control reg. is in the thread structure
 240		 */
 241		tmp = child->thread.fpu.fpc;
 242		tmp <<= BITS_PER_LONG - 32;
 243
 244	} else if (addr < offsetof(struct user, regs.fp_regs) + sizeof(s390_fp_regs)) {
 245		/*
 246		 * floating point regs. are either in child->thread.fpu
 247		 * or the child->thread.fpu.vxrs array
 248		 */
 249		offset = addr - offsetof(struct user, regs.fp_regs.fprs);
 250		if (MACHINE_HAS_VX)
 251			tmp = *(addr_t *)
 252			       ((addr_t) child->thread.fpu.vxrs + 2*offset);
 253		else
 254			tmp = *(addr_t *)
 255			       ((addr_t) child->thread.fpu.fprs + offset);
 256
 257	} else if (addr < offsetof(struct user, regs.per_info) + sizeof(per_struct)) {
 258		/*
 259		 * Handle access to the per_info structure.
 260		 */
 261		addr -= offsetof(struct user, regs.per_info);
 262		tmp = __peek_user_per(child, addr);
 263
 264	} else
 265		tmp = 0;
 266
 267	return tmp;
 268}
 269
 270static int
 271peek_user(struct task_struct *child, addr_t addr, addr_t data)
 272{
 273	addr_t tmp, mask;
 274
 275	/*
 276	 * Stupid gdb peeks/pokes the access registers in 64 bit with
 277	 * an alignment of 4. Programmers from hell...
 278	 */
 279	mask = __ADDR_MASK;
 280	if (addr >= offsetof(struct user, regs.acrs) &&
 281	    addr < offsetof(struct user, regs.orig_gpr2))
 282		mask = 3;
 283	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 284		return -EIO;
 285
 286	tmp = __peek_user(child, addr);
 287	return put_user(tmp, (addr_t __user *) data);
 288}
 289
 290static inline void __poke_user_per(struct task_struct *child,
 291				   addr_t addr, addr_t data)
 292{
 293	/*
 294	 * There are only three fields in the per_info struct that the
 295	 * debugger user can write to.
 296	 * 1) cr9: the debugger wants to set a new PER event mask
 297	 * 2) starting_addr: the debugger wants to set a new starting
 298	 *    address to use with the PER event mask.
 299	 * 3) ending_addr: the debugger wants to set a new ending
 300	 *    address to use with the PER event mask.
 301	 * The user specified PER event mask and the start and end
 302	 * addresses are used only if single stepping is not in effect.
 303	 * Writes to any other field in per_info are ignored.
 304	 */
 305	if (addr == offsetof(struct per_struct_kernel, cr9))
 306		/* PER event mask of the user specified per set. */
 307		child->thread.per_user.control =
 308			data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 309	else if (addr == offsetof(struct per_struct_kernel, starting_addr))
 310		/* Starting address of the user specified per set. */
 311		child->thread.per_user.start = data;
 312	else if (addr == offsetof(struct per_struct_kernel, ending_addr))
 313		/* Ending address of the user specified per set. */
 314		child->thread.per_user.end = data;
 315}
 316
 317/*
 318 * Write a word to the user area of a process at location addr. This
 319 * operation does have an additional problem compared to peek_user.
 320 * Stores to the program status word and on the floating point
 321 * control register needs to get checked for validity.
 322 */
 323static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 324{
 325	addr_t offset;
 326
 327
 328	if (addr < offsetof(struct user, regs.acrs)) {
 329		struct pt_regs *regs = task_pt_regs(child);
 330		/*
 331		 * psw and gprs are stored on the stack
 332		 */
 333		if (addr == offsetof(struct user, regs.psw.mask)) {
 334			unsigned long mask = PSW_MASK_USER;
 335
 336			mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
 337			if ((data ^ PSW_USER_BITS) & ~mask)
 338				/* Invalid psw mask. */
 339				return -EINVAL;
 340			if ((data & PSW_MASK_ASC) == PSW_ASC_HOME)
 341				/* Invalid address-space-control bits */
 342				return -EINVAL;
 343			if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
 344				/* Invalid addressing mode bits */
 345				return -EINVAL;
 346		}
 347
 348		if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
 349			addr == offsetof(struct user, regs.gprs[2])) {
 350			struct pt_regs *regs = task_pt_regs(child);
 351
 352			regs->int_code = 0x20000 | (data & 0xffff);
 353		}
 354		*(addr_t *)((addr_t) &regs->psw + addr) = data;
 355	} else if (addr < offsetof(struct user, regs.orig_gpr2)) {
 356		/*
 357		 * access registers are stored in the thread structure
 358		 */
 359		offset = addr - offsetof(struct user, regs.acrs);
 360		/*
 361		 * Very special case: old & broken 64 bit gdb writing
 362		 * to acrs[15] with a 64 bit value. Ignore the lower
 363		 * half of the value and write the upper 32 bit to
 364		 * acrs[15]. Sick...
 365		 */
 366		if (addr == offsetof(struct user, regs.acrs[15]))
 367			child->thread.acrs[15] = (unsigned int) (data >> 32);
 368		else
 369			*(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 370
 371	} else if (addr == offsetof(struct user, regs.orig_gpr2)) {
 372		/*
 373		 * orig_gpr2 is stored on the kernel stack
 374		 */
 375		task_pt_regs(child)->orig_gpr2 = data;
 376
 377	} else if (addr < offsetof(struct user, regs.fp_regs)) {
 378		/*
 379		 * prevent writes of padding hole between
 380		 * orig_gpr2 and fp_regs on s390.
 381		 */
 382		return 0;
 383
 384	} else if (addr == offsetof(struct user, regs.fp_regs.fpc)) {
 385		/*
 386		 * floating point control reg. is in the thread structure
 387		 */
 388		if ((unsigned int) data != 0 ||
 389		    test_fp_ctl(data >> (BITS_PER_LONG - 32)))
 390			return -EINVAL;
 391		child->thread.fpu.fpc = data >> (BITS_PER_LONG - 32);
 392
 393	} else if (addr < offsetof(struct user, regs.fp_regs) + sizeof(s390_fp_regs)) {
 394		/*
 395		 * floating point regs. are either in child->thread.fpu
 396		 * or the child->thread.fpu.vxrs array
 397		 */
 398		offset = addr - offsetof(struct user, regs.fp_regs.fprs);
 399		if (MACHINE_HAS_VX)
 400			*(addr_t *)((addr_t)
 401				child->thread.fpu.vxrs + 2*offset) = data;
 402		else
 403			*(addr_t *)((addr_t)
 404				child->thread.fpu.fprs + offset) = data;
 405
 406	} else if (addr < offsetof(struct user, regs.per_info) + sizeof(per_struct)) {
 407		/*
 408		 * Handle access to the per_info structure.
 409		 */
 410		addr -= offsetof(struct user, regs.per_info);
 411		__poke_user_per(child, addr, data);
 412
 413	}
 414
 415	return 0;
 416}
 417
 418static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
 419{
 420	addr_t mask;
 421
 422	/*
 423	 * Stupid gdb peeks/pokes the access registers in 64 bit with
 424	 * an alignment of 4. Programmers from hell indeed...
 425	 */
 426	mask = __ADDR_MASK;
 427	if (addr >= offsetof(struct user, regs.acrs) &&
 428	    addr < offsetof(struct user, regs.orig_gpr2))
 429		mask = 3;
 430	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 431		return -EIO;
 432
 433	return __poke_user(child, addr, data);
 434}
 435
 436long arch_ptrace(struct task_struct *child, long request,
 437		 unsigned long addr, unsigned long data)
 438{
 439	ptrace_area parea; 
 440	int copied, ret;
 441
 442	switch (request) {
 443	case PTRACE_PEEKUSR:
 444		/* read the word at location addr in the USER area. */
 445		return peek_user(child, addr, data);
 446
 447	case PTRACE_POKEUSR:
 448		/* write the word at location addr in the USER area */
 449		return poke_user(child, addr, data);
 450
 451	case PTRACE_PEEKUSR_AREA:
 452	case PTRACE_POKEUSR_AREA:
 453		if (copy_from_user(&parea, (void __force __user *) addr,
 454							sizeof(parea)))
 455			return -EFAULT;
 456		addr = parea.kernel_addr;
 457		data = parea.process_addr;
 458		copied = 0;
 459		while (copied < parea.len) {
 460			if (request == PTRACE_PEEKUSR_AREA)
 461				ret = peek_user(child, addr, data);
 462			else {
 463				addr_t utmp;
 464				if (get_user(utmp,
 465					     (addr_t __force __user *) data))
 466					return -EFAULT;
 467				ret = poke_user(child, addr, utmp);
 468			}
 469			if (ret)
 470				return ret;
 471			addr += sizeof(unsigned long);
 472			data += sizeof(unsigned long);
 473			copied += sizeof(unsigned long);
 474		}
 475		return 0;
 476	case PTRACE_GET_LAST_BREAK:
 477		put_user(child->thread.last_break,
 478			 (unsigned long __user *) data);
 479		return 0;
 480	case PTRACE_ENABLE_TE:
 481		if (!MACHINE_HAS_TE)
 482			return -EIO;
 483		child->thread.per_flags &= ~PER_FLAG_NO_TE;
 484		return 0;
 485	case PTRACE_DISABLE_TE:
 486		if (!MACHINE_HAS_TE)
 487			return -EIO;
 488		child->thread.per_flags |= PER_FLAG_NO_TE;
 489		child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 490		return 0;
 491	case PTRACE_TE_ABORT_RAND:
 492		if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
 493			return -EIO;
 494		switch (data) {
 495		case 0UL:
 496			child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 497			break;
 498		case 1UL:
 499			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 500			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
 501			break;
 502		case 2UL:
 503			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 504			child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
 505			break;
 506		default:
 507			return -EINVAL;
 508		}
 509		return 0;
 510	default:
 511		return ptrace_request(child, request, addr, data);
 512	}
 513}
 514
 515#ifdef CONFIG_COMPAT
 516/*
 517 * Now the fun part starts... a 31 bit program running in the
 518 * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 519 * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 520 * to handle, the difference to the 64 bit versions of the requests
 521 * is that the access is done in multiples of 4 byte instead of
 522 * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 523 * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 524 * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 525 * is a 31 bit program too, the content of struct user can be
 526 * emulated. A 31 bit program peeking into the struct user of
 527 * a 64 bit program is a no-no.
 528 */
 529
 530/*
 531 * Same as peek_user_per but for a 31 bit program.
 532 */
 533static inline __u32 __peek_user_per_compat(struct task_struct *child,
 534					   addr_t addr)
 535{
 536	if (addr == offsetof(struct compat_per_struct_kernel, cr9))
 537		/* Control bits of the active per set. */
 538		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 539			PER_EVENT_IFETCH : child->thread.per_user.control;
 540	else if (addr == offsetof(struct compat_per_struct_kernel, cr10))
 541		/* Start address of the active per set. */
 542		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 543			0 : child->thread.per_user.start;
 544	else if (addr == offsetof(struct compat_per_struct_kernel, cr11))
 545		/* End address of the active per set. */
 546		return test_thread_flag(TIF_SINGLE_STEP) ?
 547			PSW32_ADDR_INSN : child->thread.per_user.end;
 548	else if (addr == offsetof(struct compat_per_struct_kernel, bits))
 549		/* Single-step bit. */
 550		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 551			0x80000000 : 0;
 552	else if (addr == offsetof(struct compat_per_struct_kernel, starting_addr))
 553		/* Start address of the user specified per set. */
 554		return (__u32) child->thread.per_user.start;
 555	else if (addr == offsetof(struct compat_per_struct_kernel, ending_addr))
 556		/* End address of the user specified per set. */
 557		return (__u32) child->thread.per_user.end;
 558	else if (addr == offsetof(struct compat_per_struct_kernel, perc_atmid))
 559		/* PER code, ATMID and AI of the last PER trap */
 560		return (__u32) child->thread.per_event.cause << 16;
 561	else if (addr == offsetof(struct compat_per_struct_kernel, address))
 562		/* Address of the last PER trap */
 563		return (__u32) child->thread.per_event.address;
 564	else if (addr == offsetof(struct compat_per_struct_kernel, access_id))
 565		/* Access id of the last PER trap */
 566		return (__u32) child->thread.per_event.paid << 24;
 567	return 0;
 568}
 569
 570/*
 571 * Same as peek_user but for a 31 bit program.
 572 */
 573static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 574{
 575	addr_t offset;
 576	__u32 tmp;
 577
 578	if (addr < offsetof(struct compat_user, regs.acrs)) {
 579		struct pt_regs *regs = task_pt_regs(child);
 580		/*
 581		 * psw and gprs are stored on the stack
 582		 */
 583		if (addr == offsetof(struct compat_user, regs.psw.mask)) {
 584			/* Fake a 31 bit psw mask. */
 585			tmp = (__u32)(regs->psw.mask >> 32);
 586			tmp &= PSW32_MASK_USER | PSW32_MASK_RI;
 587			tmp |= PSW32_USER_BITS;
 588		} else if (addr == offsetof(struct compat_user, regs.psw.addr)) {
 589			/* Fake a 31 bit psw address. */
 590			tmp = (__u32) regs->psw.addr |
 591				(__u32)(regs->psw.mask & PSW_MASK_BA);
 592		} else {
 593			/* gpr 0-15 */
 594			tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
 595		}
 596	} else if (addr < offsetof(struct compat_user, regs.orig_gpr2)) {
 597		/*
 598		 * access registers are stored in the thread structure
 599		 */
 600		offset = addr - offsetof(struct compat_user, regs.acrs);
 601		tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 602
 603	} else if (addr == offsetof(struct compat_user, regs.orig_gpr2)) {
 604		/*
 605		 * orig_gpr2 is stored on the kernel stack
 606		 */
 607		tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 608
 609	} else if (addr < offsetof(struct compat_user, regs.fp_regs)) {
 610		/*
 611		 * prevent reads of padding hole between
 612		 * orig_gpr2 and fp_regs on s390.
 613		 */
 614		tmp = 0;
 615
 616	} else if (addr == offsetof(struct compat_user, regs.fp_regs.fpc)) {
 617		/*
 618		 * floating point control reg. is in the thread structure
 619		 */
 620		tmp = child->thread.fpu.fpc;
 621
 622	} else if (addr < offsetof(struct compat_user, regs.fp_regs) + sizeof(s390_fp_regs)) {
 623		/*
 624		 * floating point regs. are either in child->thread.fpu
 625		 * or the child->thread.fpu.vxrs array
 626		 */
 627		offset = addr - offsetof(struct compat_user, regs.fp_regs.fprs);
 628		if (MACHINE_HAS_VX)
 629			tmp = *(__u32 *)
 630			       ((addr_t) child->thread.fpu.vxrs + 2*offset);
 631		else
 632			tmp = *(__u32 *)
 633			       ((addr_t) child->thread.fpu.fprs + offset);
 634
 635	} else if (addr < offsetof(struct compat_user, regs.per_info) + sizeof(struct compat_per_struct_kernel)) {
 636		/*
 637		 * Handle access to the per_info structure.
 638		 */
 639		addr -= offsetof(struct compat_user, regs.per_info);
 640		tmp = __peek_user_per_compat(child, addr);
 641
 642	} else
 643		tmp = 0;
 644
 645	return tmp;
 646}
 647
 648static int peek_user_compat(struct task_struct *child,
 649			    addr_t addr, addr_t data)
 650{
 651	__u32 tmp;
 652
 653	if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
 654		return -EIO;
 655
 656	tmp = __peek_user_compat(child, addr);
 657	return put_user(tmp, (__u32 __user *) data);
 658}
 659
 660/*
 661 * Same as poke_user_per but for a 31 bit program.
 662 */
 663static inline void __poke_user_per_compat(struct task_struct *child,
 664					  addr_t addr, __u32 data)
 665{
 666	if (addr == offsetof(struct compat_per_struct_kernel, cr9))
 667		/* PER event mask of the user specified per set. */
 668		child->thread.per_user.control =
 669			data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 670	else if (addr == offsetof(struct compat_per_struct_kernel, starting_addr))
 671		/* Starting address of the user specified per set. */
 672		child->thread.per_user.start = data;
 673	else if (addr == offsetof(struct compat_per_struct_kernel, ending_addr))
 674		/* Ending address of the user specified per set. */
 675		child->thread.per_user.end = data;
 676}
 677
 678/*
 679 * Same as poke_user but for a 31 bit program.
 680 */
 681static int __poke_user_compat(struct task_struct *child,
 682			      addr_t addr, addr_t data)
 683{
 684	__u32 tmp = (__u32) data;
 685	addr_t offset;
 686
 687	if (addr < offsetof(struct compat_user, regs.acrs)) {
 688		struct pt_regs *regs = task_pt_regs(child);
 689		/*
 690		 * psw, gprs, acrs and orig_gpr2 are stored on the stack
 691		 */
 692		if (addr == offsetof(struct compat_user, regs.psw.mask)) {
 693			__u32 mask = PSW32_MASK_USER;
 694
 695			mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
 696			/* Build a 64 bit psw mask from 31 bit mask. */
 697			if ((tmp ^ PSW32_USER_BITS) & ~mask)
 698				/* Invalid psw mask. */
 699				return -EINVAL;
 700			if ((data & PSW32_MASK_ASC) == PSW32_ASC_HOME)
 701				/* Invalid address-space-control bits */
 702				return -EINVAL;
 703			regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
 704				(regs->psw.mask & PSW_MASK_BA) |
 705				(__u64)(tmp & mask) << 32;
 706		} else if (addr == offsetof(struct compat_user, regs.psw.addr)) {
 707			/* Build a 64 bit psw address from 31 bit address. */
 708			regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
 709			/* Transfer 31 bit amode bit to psw mask. */
 710			regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
 711				(__u64)(tmp & PSW32_ADDR_AMODE);
 712		} else {
 713			if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
 714				addr == offsetof(struct compat_user, regs.gprs[2])) {
 715				struct pt_regs *regs = task_pt_regs(child);
 716
 717				regs->int_code = 0x20000 | (data & 0xffff);
 718			}
 719			/* gpr 0-15 */
 720			*(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
 721		}
 722	} else if (addr < offsetof(struct compat_user, regs.orig_gpr2)) {
 723		/*
 724		 * access registers are stored in the thread structure
 725		 */
 726		offset = addr - offsetof(struct compat_user, regs.acrs);
 727		*(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 728
 729	} else if (addr == offsetof(struct compat_user, regs.orig_gpr2)) {
 730		/*
 731		 * orig_gpr2 is stored on the kernel stack
 732		 */
 733		*(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 734
 735	} else if (addr < offsetof(struct compat_user, regs.fp_regs)) {
 736		/*
 737		 * prevent writess of padding hole between
 738		 * orig_gpr2 and fp_regs on s390.
 739		 */
 740		return 0;
 741
 742	} else if (addr == offsetof(struct compat_user, regs.fp_regs.fpc)) {
 743		/*
 744		 * floating point control reg. is in the thread structure
 745		 */
 746		if (test_fp_ctl(tmp))
 747			return -EINVAL;
 748		child->thread.fpu.fpc = data;
 749
 750	} else if (addr < offsetof(struct compat_user, regs.fp_regs) + sizeof(s390_fp_regs)) {
 751		/*
 752		 * floating point regs. are either in child->thread.fpu
 753		 * or the child->thread.fpu.vxrs array
 754		 */
 755		offset = addr - offsetof(struct compat_user, regs.fp_regs.fprs);
 756		if (MACHINE_HAS_VX)
 757			*(__u32 *)((addr_t)
 758				child->thread.fpu.vxrs + 2*offset) = tmp;
 759		else
 760			*(__u32 *)((addr_t)
 761				child->thread.fpu.fprs + offset) = tmp;
 762
 763	} else if (addr < offsetof(struct compat_user, regs.per_info) + sizeof(struct compat_per_struct_kernel)) {
 764		/*
 765		 * Handle access to the per_info structure.
 766		 */
 767		addr -= offsetof(struct compat_user, regs.per_info);
 768		__poke_user_per_compat(child, addr, data);
 769	}
 770
 771	return 0;
 772}
 773
 774static int poke_user_compat(struct task_struct *child,
 775			    addr_t addr, addr_t data)
 776{
 777	if (!is_compat_task() || (addr & 3) ||
 778	    addr > sizeof(struct compat_user) - 3)
 779		return -EIO;
 780
 781	return __poke_user_compat(child, addr, data);
 782}
 783
 784long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 785			compat_ulong_t caddr, compat_ulong_t cdata)
 786{
 787	unsigned long addr = caddr;
 788	unsigned long data = cdata;
 789	compat_ptrace_area parea;
 790	int copied, ret;
 791
 792	switch (request) {
 793	case PTRACE_PEEKUSR:
 794		/* read the word at location addr in the USER area. */
 795		return peek_user_compat(child, addr, data);
 796
 797	case PTRACE_POKEUSR:
 798		/* write the word at location addr in the USER area */
 799		return poke_user_compat(child, addr, data);
 800
 801	case PTRACE_PEEKUSR_AREA:
 802	case PTRACE_POKEUSR_AREA:
 803		if (copy_from_user(&parea, (void __force __user *) addr,
 804							sizeof(parea)))
 805			return -EFAULT;
 806		addr = parea.kernel_addr;
 807		data = parea.process_addr;
 808		copied = 0;
 809		while (copied < parea.len) {
 810			if (request == PTRACE_PEEKUSR_AREA)
 811				ret = peek_user_compat(child, addr, data);
 812			else {
 813				__u32 utmp;
 814				if (get_user(utmp,
 815					     (__u32 __force __user *) data))
 816					return -EFAULT;
 817				ret = poke_user_compat(child, addr, utmp);
 818			}
 819			if (ret)
 820				return ret;
 821			addr += sizeof(unsigned int);
 822			data += sizeof(unsigned int);
 823			copied += sizeof(unsigned int);
 824		}
 825		return 0;
 826	case PTRACE_GET_LAST_BREAK:
 827		put_user(child->thread.last_break,
 828			 (unsigned int __user *) data);
 829		return 0;
 830	}
 831	return compat_ptrace_request(child, request, addr, data);
 832}
 833#endif
 834
 835/*
 836 * user_regset definitions.
 837 */
 838
 839static int s390_regs_get(struct task_struct *target,
 840			 const struct user_regset *regset,
 841			 struct membuf to)
 842{
 843	unsigned pos;
 844	if (target == current)
 845		save_access_regs(target->thread.acrs);
 846
 847	for (pos = 0; pos < sizeof(s390_regs); pos += sizeof(long))
 848		membuf_store(&to, __peek_user(target, pos));
 849	return 0;
 850}
 851
 852static int s390_regs_set(struct task_struct *target,
 853			 const struct user_regset *regset,
 854			 unsigned int pos, unsigned int count,
 855			 const void *kbuf, const void __user *ubuf)
 856{
 857	int rc = 0;
 858
 859	if (target == current)
 860		save_access_regs(target->thread.acrs);
 861
 862	if (kbuf) {
 863		const unsigned long *k = kbuf;
 864		while (count > 0 && !rc) {
 865			rc = __poke_user(target, pos, *k++);
 866			count -= sizeof(*k);
 867			pos += sizeof(*k);
 868		}
 869	} else {
 870		const unsigned long  __user *u = ubuf;
 871		while (count > 0 && !rc) {
 872			unsigned long word;
 873			rc = __get_user(word, u++);
 874			if (rc)
 875				break;
 876			rc = __poke_user(target, pos, word);
 877			count -= sizeof(*u);
 878			pos += sizeof(*u);
 879		}
 880	}
 881
 882	if (rc == 0 && target == current)
 883		restore_access_regs(target->thread.acrs);
 884
 885	return rc;
 886}
 887
 888static int s390_fpregs_get(struct task_struct *target,
 889			   const struct user_regset *regset,
 890			   struct membuf to)
 891{
 892	_s390_fp_regs fp_regs;
 893
 894	if (target == current)
 895		save_fpu_regs();
 896
 897	fp_regs.fpc = target->thread.fpu.fpc;
 898	fpregs_store(&fp_regs, &target->thread.fpu);
 899
 900	return membuf_write(&to, &fp_regs, sizeof(fp_regs));
 901}
 902
 903static int s390_fpregs_set(struct task_struct *target,
 904			   const struct user_regset *regset, unsigned int pos,
 905			   unsigned int count, const void *kbuf,
 906			   const void __user *ubuf)
 907{
 908	int rc = 0;
 909	freg_t fprs[__NUM_FPRS];
 910
 911	if (target == current)
 912		save_fpu_regs();
 913
 914	if (MACHINE_HAS_VX)
 915		convert_vx_to_fp(fprs, target->thread.fpu.vxrs);
 916	else
 917		memcpy(&fprs, target->thread.fpu.fprs, sizeof(fprs));
 918
 919	/* If setting FPC, must validate it first. */
 920	if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 921		u32 ufpc[2] = { target->thread.fpu.fpc, 0 };
 922		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
 923					0, offsetof(s390_fp_regs, fprs));
 924		if (rc)
 925			return rc;
 926		if (ufpc[1] != 0 || test_fp_ctl(ufpc[0]))
 927			return -EINVAL;
 928		target->thread.fpu.fpc = ufpc[0];
 929	}
 930
 931	if (rc == 0 && count > 0)
 932		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 933					fprs, offsetof(s390_fp_regs, fprs), -1);
 934	if (rc)
 935		return rc;
 936
 937	if (MACHINE_HAS_VX)
 938		convert_fp_to_vx(target->thread.fpu.vxrs, fprs);
 939	else
 940		memcpy(target->thread.fpu.fprs, &fprs, sizeof(fprs));
 941
 942	return rc;
 943}
 944
 945static int s390_last_break_get(struct task_struct *target,
 946			       const struct user_regset *regset,
 947			       struct membuf to)
 948{
 949	return membuf_store(&to, target->thread.last_break);
 950}
 951
 952static int s390_last_break_set(struct task_struct *target,
 953			       const struct user_regset *regset,
 954			       unsigned int pos, unsigned int count,
 955			       const void *kbuf, const void __user *ubuf)
 956{
 957	return 0;
 958}
 959
 960static int s390_tdb_get(struct task_struct *target,
 961			const struct user_regset *regset,
 962			struct membuf to)
 963{
 964	struct pt_regs *regs = task_pt_regs(target);
 965	size_t size;
 966
 967	if (!(regs->int_code & 0x200))
 968		return -ENODATA;
 969	size = sizeof(target->thread.trap_tdb.data);
 970	return membuf_write(&to, target->thread.trap_tdb.data, size);
 971}
 972
 973static int s390_tdb_set(struct task_struct *target,
 974			const struct user_regset *regset,
 975			unsigned int pos, unsigned int count,
 976			const void *kbuf, const void __user *ubuf)
 977{
 978	return 0;
 979}
 980
 981static int s390_vxrs_low_get(struct task_struct *target,
 982			     const struct user_regset *regset,
 983			     struct membuf to)
 984{
 985	__u64 vxrs[__NUM_VXRS_LOW];
 986	int i;
 987
 988	if (!MACHINE_HAS_VX)
 989		return -ENODEV;
 990	if (target == current)
 991		save_fpu_regs();
 992	for (i = 0; i < __NUM_VXRS_LOW; i++)
 993		vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
 994	return membuf_write(&to, vxrs, sizeof(vxrs));
 995}
 996
 997static int s390_vxrs_low_set(struct task_struct *target,
 998			     const struct user_regset *regset,
 999			     unsigned int pos, unsigned int count,
1000			     const void *kbuf, const void __user *ubuf)
1001{
1002	__u64 vxrs[__NUM_VXRS_LOW];
1003	int i, rc;
1004
1005	if (!MACHINE_HAS_VX)
1006		return -ENODEV;
1007	if (target == current)
1008		save_fpu_regs();
1009
1010	for (i = 0; i < __NUM_VXRS_LOW; i++)
1011		vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1012
1013	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1014	if (rc == 0)
1015		for (i = 0; i < __NUM_VXRS_LOW; i++)
1016			*((__u64 *)(target->thread.fpu.vxrs + i) + 1) = vxrs[i];
1017
1018	return rc;
1019}
1020
1021static int s390_vxrs_high_get(struct task_struct *target,
1022			      const struct user_regset *regset,
1023			      struct membuf to)
1024{
1025	if (!MACHINE_HAS_VX)
1026		return -ENODEV;
1027	if (target == current)
1028		save_fpu_regs();
1029	return membuf_write(&to, target->thread.fpu.vxrs + __NUM_VXRS_LOW,
1030			    __NUM_VXRS_HIGH * sizeof(__vector128));
1031}
1032
1033static int s390_vxrs_high_set(struct task_struct *target,
1034			      const struct user_regset *regset,
1035			      unsigned int pos, unsigned int count,
1036			      const void *kbuf, const void __user *ubuf)
1037{
1038	int rc;
1039
1040	if (!MACHINE_HAS_VX)
1041		return -ENODEV;
1042	if (target == current)
1043		save_fpu_regs();
1044
1045	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1046				target->thread.fpu.vxrs + __NUM_VXRS_LOW, 0, -1);
1047	return rc;
1048}
1049
1050static int s390_system_call_get(struct task_struct *target,
1051				const struct user_regset *regset,
1052				struct membuf to)
1053{
1054	return membuf_store(&to, target->thread.system_call);
1055}
1056
1057static int s390_system_call_set(struct task_struct *target,
1058				const struct user_regset *regset,
1059				unsigned int pos, unsigned int count,
1060				const void *kbuf, const void __user *ubuf)
1061{
1062	unsigned int *data = &target->thread.system_call;
1063	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1064				  data, 0, sizeof(unsigned int));
1065}
1066
1067static int s390_gs_cb_get(struct task_struct *target,
1068			  const struct user_regset *regset,
1069			  struct membuf to)
1070{
1071	struct gs_cb *data = target->thread.gs_cb;
1072
1073	if (!MACHINE_HAS_GS)
1074		return -ENODEV;
1075	if (!data)
1076		return -ENODATA;
1077	if (target == current)
1078		save_gs_cb(data);
1079	return membuf_write(&to, data, sizeof(struct gs_cb));
1080}
1081
1082static int s390_gs_cb_set(struct task_struct *target,
1083			  const struct user_regset *regset,
1084			  unsigned int pos, unsigned int count,
1085			  const void *kbuf, const void __user *ubuf)
1086{
1087	struct gs_cb gs_cb = { }, *data = NULL;
1088	int rc;
1089
1090	if (!MACHINE_HAS_GS)
1091		return -ENODEV;
1092	if (!target->thread.gs_cb) {
1093		data = kzalloc(sizeof(*data), GFP_KERNEL);
1094		if (!data)
1095			return -ENOMEM;
1096	}
1097	if (!target->thread.gs_cb)
1098		gs_cb.gsd = 25;
1099	else if (target == current)
1100		save_gs_cb(&gs_cb);
1101	else
1102		gs_cb = *target->thread.gs_cb;
1103	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1104				&gs_cb, 0, sizeof(gs_cb));
1105	if (rc) {
1106		kfree(data);
1107		return -EFAULT;
1108	}
1109	preempt_disable();
1110	if (!target->thread.gs_cb)
1111		target->thread.gs_cb = data;
1112	*target->thread.gs_cb = gs_cb;
1113	if (target == current) {
1114		__ctl_set_bit(2, 4);
1115		restore_gs_cb(target->thread.gs_cb);
1116	}
1117	preempt_enable();
1118	return rc;
1119}
1120
1121static int s390_gs_bc_get(struct task_struct *target,
1122			  const struct user_regset *regset,
1123			  struct membuf to)
1124{
1125	struct gs_cb *data = target->thread.gs_bc_cb;
1126
1127	if (!MACHINE_HAS_GS)
1128		return -ENODEV;
1129	if (!data)
1130		return -ENODATA;
1131	return membuf_write(&to, data, sizeof(struct gs_cb));
1132}
1133
1134static int s390_gs_bc_set(struct task_struct *target,
1135			  const struct user_regset *regset,
1136			  unsigned int pos, unsigned int count,
1137			  const void *kbuf, const void __user *ubuf)
1138{
1139	struct gs_cb *data = target->thread.gs_bc_cb;
1140
1141	if (!MACHINE_HAS_GS)
1142		return -ENODEV;
1143	if (!data) {
1144		data = kzalloc(sizeof(*data), GFP_KERNEL);
1145		if (!data)
1146			return -ENOMEM;
1147		target->thread.gs_bc_cb = data;
1148	}
1149	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1150				  data, 0, sizeof(struct gs_cb));
1151}
1152
1153static bool is_ri_cb_valid(struct runtime_instr_cb *cb)
1154{
1155	return (cb->rca & 0x1f) == 0 &&
1156		(cb->roa & 0xfff) == 0 &&
1157		(cb->rla & 0xfff) == 0xfff &&
1158		cb->s == 1 &&
1159		cb->k == 1 &&
1160		cb->h == 0 &&
1161		cb->reserved1 == 0 &&
1162		cb->ps == 1 &&
1163		cb->qs == 0 &&
1164		cb->pc == 1 &&
1165		cb->qc == 0 &&
1166		cb->reserved2 == 0 &&
1167		cb->reserved3 == 0 &&
1168		cb->reserved4 == 0 &&
1169		cb->reserved5 == 0 &&
1170		cb->reserved6 == 0 &&
1171		cb->reserved7 == 0 &&
1172		cb->reserved8 == 0 &&
1173		cb->rla >= cb->roa &&
1174		cb->rca >= cb->roa &&
1175		cb->rca <= cb->rla+1 &&
1176		cb->m < 3;
1177}
1178
1179static int s390_runtime_instr_get(struct task_struct *target,
1180				const struct user_regset *regset,
1181				struct membuf to)
1182{
1183	struct runtime_instr_cb *data = target->thread.ri_cb;
1184
1185	if (!test_facility(64))
1186		return -ENODEV;
1187	if (!data)
1188		return -ENODATA;
1189
1190	return membuf_write(&to, data, sizeof(struct runtime_instr_cb));
1191}
1192
1193static int s390_runtime_instr_set(struct task_struct *target,
1194				  const struct user_regset *regset,
1195				  unsigned int pos, unsigned int count,
1196				  const void *kbuf, const void __user *ubuf)
1197{
1198	struct runtime_instr_cb ri_cb = { }, *data = NULL;
1199	int rc;
1200
1201	if (!test_facility(64))
1202		return -ENODEV;
1203
1204	if (!target->thread.ri_cb) {
1205		data = kzalloc(sizeof(*data), GFP_KERNEL);
1206		if (!data)
1207			return -ENOMEM;
1208	}
1209
1210	if (target->thread.ri_cb) {
1211		if (target == current)
1212			store_runtime_instr_cb(&ri_cb);
1213		else
1214			ri_cb = *target->thread.ri_cb;
1215	}
1216
1217	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1218				&ri_cb, 0, sizeof(struct runtime_instr_cb));
1219	if (rc) {
1220		kfree(data);
1221		return -EFAULT;
1222	}
1223
1224	if (!is_ri_cb_valid(&ri_cb)) {
1225		kfree(data);
1226		return -EINVAL;
1227	}
1228	/*
1229	 * Override access key in any case, since user space should
1230	 * not be able to set it, nor should it care about it.
1231	 */
1232	ri_cb.key = PAGE_DEFAULT_KEY >> 4;
1233	preempt_disable();
1234	if (!target->thread.ri_cb)
1235		target->thread.ri_cb = data;
1236	*target->thread.ri_cb = ri_cb;
1237	if (target == current)
1238		load_runtime_instr_cb(target->thread.ri_cb);
1239	preempt_enable();
1240
1241	return 0;
1242}
1243
1244static const struct user_regset s390_regsets[] = {
1245	{
1246		.core_note_type = NT_PRSTATUS,
1247		.n = sizeof(s390_regs) / sizeof(long),
1248		.size = sizeof(long),
1249		.align = sizeof(long),
1250		.regset_get = s390_regs_get,
1251		.set = s390_regs_set,
1252	},
1253	{
1254		.core_note_type = NT_PRFPREG,
1255		.n = sizeof(s390_fp_regs) / sizeof(long),
1256		.size = sizeof(long),
1257		.align = sizeof(long),
1258		.regset_get = s390_fpregs_get,
1259		.set = s390_fpregs_set,
1260	},
1261	{
1262		.core_note_type = NT_S390_SYSTEM_CALL,
1263		.n = 1,
1264		.size = sizeof(unsigned int),
1265		.align = sizeof(unsigned int),
1266		.regset_get = s390_system_call_get,
1267		.set = s390_system_call_set,
1268	},
1269	{
1270		.core_note_type = NT_S390_LAST_BREAK,
1271		.n = 1,
1272		.size = sizeof(long),
1273		.align = sizeof(long),
1274		.regset_get = s390_last_break_get,
1275		.set = s390_last_break_set,
1276	},
1277	{
1278		.core_note_type = NT_S390_TDB,
1279		.n = 1,
1280		.size = 256,
1281		.align = 1,
1282		.regset_get = s390_tdb_get,
1283		.set = s390_tdb_set,
1284	},
1285	{
1286		.core_note_type = NT_S390_VXRS_LOW,
1287		.n = __NUM_VXRS_LOW,
1288		.size = sizeof(__u64),
1289		.align = sizeof(__u64),
1290		.regset_get = s390_vxrs_low_get,
1291		.set = s390_vxrs_low_set,
1292	},
1293	{
1294		.core_note_type = NT_S390_VXRS_HIGH,
1295		.n = __NUM_VXRS_HIGH,
1296		.size = sizeof(__vector128),
1297		.align = sizeof(__vector128),
1298		.regset_get = s390_vxrs_high_get,
1299		.set = s390_vxrs_high_set,
1300	},
1301	{
1302		.core_note_type = NT_S390_GS_CB,
1303		.n = sizeof(struct gs_cb) / sizeof(__u64),
1304		.size = sizeof(__u64),
1305		.align = sizeof(__u64),
1306		.regset_get = s390_gs_cb_get,
1307		.set = s390_gs_cb_set,
1308	},
1309	{
1310		.core_note_type = NT_S390_GS_BC,
1311		.n = sizeof(struct gs_cb) / sizeof(__u64),
1312		.size = sizeof(__u64),
1313		.align = sizeof(__u64),
1314		.regset_get = s390_gs_bc_get,
1315		.set = s390_gs_bc_set,
1316	},
1317	{
1318		.core_note_type = NT_S390_RI_CB,
1319		.n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1320		.size = sizeof(__u64),
1321		.align = sizeof(__u64),
1322		.regset_get = s390_runtime_instr_get,
1323		.set = s390_runtime_instr_set,
1324	},
1325};
1326
1327static const struct user_regset_view user_s390_view = {
1328	.name = "s390x",
1329	.e_machine = EM_S390,
1330	.regsets = s390_regsets,
1331	.n = ARRAY_SIZE(s390_regsets)
1332};
1333
1334#ifdef CONFIG_COMPAT
1335static int s390_compat_regs_get(struct task_struct *target,
1336				const struct user_regset *regset,
1337				struct membuf to)
1338{
1339	unsigned n;
1340
1341	if (target == current)
1342		save_access_regs(target->thread.acrs);
1343
1344	for (n = 0; n < sizeof(s390_compat_regs); n += sizeof(compat_ulong_t))
1345		membuf_store(&to, __peek_user_compat(target, n));
1346	return 0;
1347}
1348
1349static int s390_compat_regs_set(struct task_struct *target,
1350				const struct user_regset *regset,
1351				unsigned int pos, unsigned int count,
1352				const void *kbuf, const void __user *ubuf)
1353{
1354	int rc = 0;
1355
1356	if (target == current)
1357		save_access_regs(target->thread.acrs);
1358
1359	if (kbuf) {
1360		const compat_ulong_t *k = kbuf;
1361		while (count > 0 && !rc) {
1362			rc = __poke_user_compat(target, pos, *k++);
1363			count -= sizeof(*k);
1364			pos += sizeof(*k);
1365		}
1366	} else {
1367		const compat_ulong_t  __user *u = ubuf;
1368		while (count > 0 && !rc) {
1369			compat_ulong_t word;
1370			rc = __get_user(word, u++);
1371			if (rc)
1372				break;
1373			rc = __poke_user_compat(target, pos, word);
1374			count -= sizeof(*u);
1375			pos += sizeof(*u);
1376		}
1377	}
1378
1379	if (rc == 0 && target == current)
1380		restore_access_regs(target->thread.acrs);
1381
1382	return rc;
1383}
1384
1385static int s390_compat_regs_high_get(struct task_struct *target,
1386				     const struct user_regset *regset,
1387				     struct membuf to)
1388{
1389	compat_ulong_t *gprs_high;
1390	int i;
1391
1392	gprs_high = (compat_ulong_t *)task_pt_regs(target)->gprs;
1393	for (i = 0; i < NUM_GPRS; i++, gprs_high += 2)
1394		membuf_store(&to, *gprs_high);
1395	return 0;
1396}
1397
1398static int s390_compat_regs_high_set(struct task_struct *target,
1399				     const struct user_regset *regset,
1400				     unsigned int pos, unsigned int count,
1401				     const void *kbuf, const void __user *ubuf)
1402{
1403	compat_ulong_t *gprs_high;
1404	int rc = 0;
1405
1406	gprs_high = (compat_ulong_t *)
1407		&task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1408	if (kbuf) {
1409		const compat_ulong_t *k = kbuf;
1410		while (count > 0) {
1411			*gprs_high = *k++;
1412			*gprs_high += 2;
1413			count -= sizeof(*k);
1414		}
1415	} else {
1416		const compat_ulong_t  __user *u = ubuf;
1417		while (count > 0 && !rc) {
1418			unsigned long word;
1419			rc = __get_user(word, u++);
1420			if (rc)
1421				break;
1422			*gprs_high = word;
1423			*gprs_high += 2;
1424			count -= sizeof(*u);
1425		}
1426	}
1427
1428	return rc;
1429}
1430
1431static int s390_compat_last_break_get(struct task_struct *target,
1432				      const struct user_regset *regset,
1433				      struct membuf to)
1434{
1435	compat_ulong_t last_break = target->thread.last_break;
1436
1437	return membuf_store(&to, (unsigned long)last_break);
1438}
1439
1440static int s390_compat_last_break_set(struct task_struct *target,
1441				      const struct user_regset *regset,
1442				      unsigned int pos, unsigned int count,
1443				      const void *kbuf, const void __user *ubuf)
1444{
1445	return 0;
1446}
1447
1448static const struct user_regset s390_compat_regsets[] = {
1449	{
1450		.core_note_type = NT_PRSTATUS,
1451		.n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1452		.size = sizeof(compat_long_t),
1453		.align = sizeof(compat_long_t),
1454		.regset_get = s390_compat_regs_get,
1455		.set = s390_compat_regs_set,
1456	},
1457	{
1458		.core_note_type = NT_PRFPREG,
1459		.n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1460		.size = sizeof(compat_long_t),
1461		.align = sizeof(compat_long_t),
1462		.regset_get = s390_fpregs_get,
1463		.set = s390_fpregs_set,
1464	},
1465	{
1466		.core_note_type = NT_S390_SYSTEM_CALL,
1467		.n = 1,
1468		.size = sizeof(compat_uint_t),
1469		.align = sizeof(compat_uint_t),
1470		.regset_get = s390_system_call_get,
1471		.set = s390_system_call_set,
1472	},
1473	{
1474		.core_note_type = NT_S390_LAST_BREAK,
1475		.n = 1,
1476		.size = sizeof(long),
1477		.align = sizeof(long),
1478		.regset_get = s390_compat_last_break_get,
1479		.set = s390_compat_last_break_set,
1480	},
1481	{
1482		.core_note_type = NT_S390_TDB,
1483		.n = 1,
1484		.size = 256,
1485		.align = 1,
1486		.regset_get = s390_tdb_get,
1487		.set = s390_tdb_set,
1488	},
1489	{
1490		.core_note_type = NT_S390_VXRS_LOW,
1491		.n = __NUM_VXRS_LOW,
1492		.size = sizeof(__u64),
1493		.align = sizeof(__u64),
1494		.regset_get = s390_vxrs_low_get,
1495		.set = s390_vxrs_low_set,
1496	},
1497	{
1498		.core_note_type = NT_S390_VXRS_HIGH,
1499		.n = __NUM_VXRS_HIGH,
1500		.size = sizeof(__vector128),
1501		.align = sizeof(__vector128),
1502		.regset_get = s390_vxrs_high_get,
1503		.set = s390_vxrs_high_set,
1504	},
1505	{
1506		.core_note_type = NT_S390_HIGH_GPRS,
1507		.n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1508		.size = sizeof(compat_long_t),
1509		.align = sizeof(compat_long_t),
1510		.regset_get = s390_compat_regs_high_get,
1511		.set = s390_compat_regs_high_set,
1512	},
1513	{
1514		.core_note_type = NT_S390_GS_CB,
1515		.n = sizeof(struct gs_cb) / sizeof(__u64),
1516		.size = sizeof(__u64),
1517		.align = sizeof(__u64),
1518		.regset_get = s390_gs_cb_get,
1519		.set = s390_gs_cb_set,
1520	},
1521	{
1522		.core_note_type = NT_S390_GS_BC,
1523		.n = sizeof(struct gs_cb) / sizeof(__u64),
1524		.size = sizeof(__u64),
1525		.align = sizeof(__u64),
1526		.regset_get = s390_gs_bc_get,
1527		.set = s390_gs_bc_set,
1528	},
1529	{
1530		.core_note_type = NT_S390_RI_CB,
1531		.n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1532		.size = sizeof(__u64),
1533		.align = sizeof(__u64),
1534		.regset_get = s390_runtime_instr_get,
1535		.set = s390_runtime_instr_set,
1536	},
1537};
1538
1539static const struct user_regset_view user_s390_compat_view = {
1540	.name = "s390",
1541	.e_machine = EM_S390,
1542	.regsets = s390_compat_regsets,
1543	.n = ARRAY_SIZE(s390_compat_regsets)
1544};
1545#endif
1546
1547const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1548{
1549#ifdef CONFIG_COMPAT
1550	if (test_tsk_thread_flag(task, TIF_31BIT))
1551		return &user_s390_compat_view;
1552#endif
1553	return &user_s390_view;
1554}
1555
1556static const char *gpr_names[NUM_GPRS] = {
1557	"r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1558	"r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1559};
1560
1561unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1562{
1563	if (offset >= NUM_GPRS)
1564		return 0;
1565	return regs->gprs[offset];
1566}
1567
1568int regs_query_register_offset(const char *name)
1569{
1570	unsigned long offset;
1571
1572	if (!name || *name != 'r')
1573		return -EINVAL;
1574	if (kstrtoul(name + 1, 10, &offset))
1575		return -EINVAL;
1576	if (offset >= NUM_GPRS)
1577		return -EINVAL;
1578	return offset;
1579}
1580
1581const char *regs_query_register_name(unsigned int offset)
1582{
1583	if (offset >= NUM_GPRS)
1584		return NULL;
1585	return gpr_names[offset];
1586}
1587
1588static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1589{
1590	unsigned long ksp = kernel_stack_pointer(regs);
1591
1592	return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1593}
1594
1595/**
1596 * regs_get_kernel_stack_nth() - get Nth entry of the stack
1597 * @regs:pt_regs which contains kernel stack pointer.
1598 * @n:stack entry number.
1599 *
1600 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1601 * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1602 * this returns 0.
1603 */
1604unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1605{
1606	unsigned long addr;
1607
1608	addr = kernel_stack_pointer(regs) + n * sizeof(long);
1609	if (!regs_within_kernel_stack(regs, addr))
1610		return 0;
1611	return *(unsigned long *)addr;
1612}
v6.8
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 *  Ptrace user space interface.
   4 *
   5 *    Copyright IBM Corp. 1999, 2010
   6 *    Author(s): Denis Joseph Barrow
   7 *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   8 */
   9
  10#include "asm/ptrace.h"
  11#include <linux/kernel.h>
  12#include <linux/sched.h>
  13#include <linux/sched/task_stack.h>
  14#include <linux/mm.h>
  15#include <linux/smp.h>
  16#include <linux/errno.h>
  17#include <linux/ptrace.h>
  18#include <linux/user.h>
  19#include <linux/security.h>
  20#include <linux/audit.h>
  21#include <linux/signal.h>
  22#include <linux/elf.h>
  23#include <linux/regset.h>
  24#include <linux/seccomp.h>
  25#include <linux/compat.h>
  26#include <trace/syscall.h>
  27#include <asm/page.h>
  28#include <linux/uaccess.h>
  29#include <asm/unistd.h>
  30#include <asm/switch_to.h>
  31#include <asm/runtime_instr.h>
  32#include <asm/facility.h>
  33#include <asm/fpu/api.h>
  34
  35#include "entry.h"
  36
  37#ifdef CONFIG_COMPAT
  38#include "compat_ptrace.h"
  39#endif
  40
  41void update_cr_regs(struct task_struct *task)
  42{
  43	struct pt_regs *regs = task_pt_regs(task);
  44	struct thread_struct *thread = &task->thread;
 
  45	union ctlreg0 cr0_old, cr0_new;
  46	union ctlreg2 cr2_old, cr2_new;
  47	int cr0_changed, cr2_changed;
  48	union {
  49		struct ctlreg regs[3];
  50		struct {
  51			struct ctlreg control;
  52			struct ctlreg start;
  53			struct ctlreg end;
  54		};
  55	} old, new;
  56
  57	local_ctl_store(0, &cr0_old.reg);
  58	local_ctl_store(2, &cr2_old.reg);
  59	cr0_new = cr0_old;
  60	cr2_new = cr2_old;
  61	/* Take care of the enable/disable of transactional execution. */
  62	if (MACHINE_HAS_TE) {
  63		/* Set or clear transaction execution TXC bit 8. */
  64		cr0_new.tcx = 1;
  65		if (task->thread.per_flags & PER_FLAG_NO_TE)
  66			cr0_new.tcx = 0;
  67		/* Set or clear transaction execution TDC bits 62 and 63. */
  68		cr2_new.tdc = 0;
  69		if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
  70			if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND_TEND)
  71				cr2_new.tdc = 1;
  72			else
  73				cr2_new.tdc = 2;
  74		}
  75	}
  76	/* Take care of enable/disable of guarded storage. */
  77	if (MACHINE_HAS_GS) {
  78		cr2_new.gse = 0;
  79		if (task->thread.gs_cb)
  80			cr2_new.gse = 1;
  81	}
  82	/* Load control register 0/2 iff changed */
  83	cr0_changed = cr0_new.val != cr0_old.val;
  84	cr2_changed = cr2_new.val != cr2_old.val;
  85	if (cr0_changed)
  86		local_ctl_load(0, &cr0_new.reg);
  87	if (cr2_changed)
  88		local_ctl_load(2, &cr2_new.reg);
  89	/* Copy user specified PER registers */
  90	new.control.val = thread->per_user.control;
  91	new.start.val = thread->per_user.start;
  92	new.end.val = thread->per_user.end;
  93
  94	/* merge TIF_SINGLE_STEP into user specified PER registers. */
  95	if (test_tsk_thread_flag(task, TIF_SINGLE_STEP) ||
  96	    test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP)) {
  97		if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))
  98			new.control.val |= PER_EVENT_BRANCH;
  99		else
 100			new.control.val |= PER_EVENT_IFETCH;
 101		new.control.val |= PER_CONTROL_SUSPENSION;
 102		new.control.val |= PER_EVENT_TRANSACTION_END;
 103		if (test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP))
 104			new.control.val |= PER_EVENT_IFETCH;
 105		new.start.val = 0;
 106		new.end.val = -1UL;
 107	}
 108
 109	/* Take care of the PER enablement bit in the PSW. */
 110	if (!(new.control.val & PER_EVENT_MASK)) {
 111		regs->psw.mask &= ~PSW_MASK_PER;
 112		return;
 113	}
 114	regs->psw.mask |= PSW_MASK_PER;
 115	__local_ctl_store(9, 11, old.regs);
 116	if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
 117		__local_ctl_load(9, 11, new.regs);
 118}
 119
 120void user_enable_single_step(struct task_struct *task)
 121{
 122	clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
 123	set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 124}
 125
 126void user_disable_single_step(struct task_struct *task)
 127{
 128	clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
 129	clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 130}
 131
 132void user_enable_block_step(struct task_struct *task)
 133{
 134	set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 135	set_tsk_thread_flag(task, TIF_BLOCK_STEP);
 136}
 137
 138/*
 139 * Called by kernel/ptrace.c when detaching..
 140 *
 141 * Clear all debugging related fields.
 142 */
 143void ptrace_disable(struct task_struct *task)
 144{
 145	memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
 146	memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
 147	clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 148	clear_tsk_thread_flag(task, TIF_PER_TRAP);
 149	task->thread.per_flags = 0;
 150}
 151
 152#define __ADDR_MASK 7
 153
 154static inline unsigned long __peek_user_per(struct task_struct *child,
 155					    addr_t addr)
 156{
 157	if (addr == offsetof(struct per_struct_kernel, cr9))
 158		/* Control bits of the active per set. */
 159		return test_thread_flag(TIF_SINGLE_STEP) ?
 160			PER_EVENT_IFETCH : child->thread.per_user.control;
 161	else if (addr == offsetof(struct per_struct_kernel, cr10))
 162		/* Start address of the active per set. */
 163		return test_thread_flag(TIF_SINGLE_STEP) ?
 164			0 : child->thread.per_user.start;
 165	else if (addr == offsetof(struct per_struct_kernel, cr11))
 166		/* End address of the active per set. */
 167		return test_thread_flag(TIF_SINGLE_STEP) ?
 168			-1UL : child->thread.per_user.end;
 169	else if (addr == offsetof(struct per_struct_kernel, bits))
 170		/* Single-step bit. */
 171		return test_thread_flag(TIF_SINGLE_STEP) ?
 172			(1UL << (BITS_PER_LONG - 1)) : 0;
 173	else if (addr == offsetof(struct per_struct_kernel, starting_addr))
 174		/* Start address of the user specified per set. */
 175		return child->thread.per_user.start;
 176	else if (addr == offsetof(struct per_struct_kernel, ending_addr))
 177		/* End address of the user specified per set. */
 178		return child->thread.per_user.end;
 179	else if (addr == offsetof(struct per_struct_kernel, perc_atmid))
 180		/* PER code, ATMID and AI of the last PER trap */
 181		return (unsigned long)
 182			child->thread.per_event.cause << (BITS_PER_LONG - 16);
 183	else if (addr == offsetof(struct per_struct_kernel, address))
 184		/* Address of the last PER trap */
 185		return child->thread.per_event.address;
 186	else if (addr == offsetof(struct per_struct_kernel, access_id))
 187		/* Access id of the last PER trap */
 188		return (unsigned long)
 189			child->thread.per_event.paid << (BITS_PER_LONG - 8);
 190	return 0;
 191}
 192
 193/*
 194 * Read the word at offset addr from the user area of a process. The
 195 * trouble here is that the information is littered over different
 196 * locations. The process registers are found on the kernel stack,
 197 * the floating point stuff and the trace settings are stored in
 198 * the task structure. In addition the different structures in
 199 * struct user contain pad bytes that should be read as zeroes.
 200 * Lovely...
 201 */
 202static unsigned long __peek_user(struct task_struct *child, addr_t addr)
 203{
 204	addr_t offset, tmp;
 205
 206	if (addr < offsetof(struct user, regs.acrs)) {
 207		/*
 208		 * psw and gprs are stored on the stack
 209		 */
 210		tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
 211		if (addr == offsetof(struct user, regs.psw.mask)) {
 212			/* Return a clean psw mask. */
 213			tmp &= PSW_MASK_USER | PSW_MASK_RI;
 214			tmp |= PSW_USER_BITS;
 215		}
 216
 217	} else if (addr < offsetof(struct user, regs.orig_gpr2)) {
 218		/*
 219		 * access registers are stored in the thread structure
 220		 */
 221		offset = addr - offsetof(struct user, regs.acrs);
 222		/*
 223		 * Very special case: old & broken 64 bit gdb reading
 224		 * from acrs[15]. Result is a 64 bit value. Read the
 225		 * 32 bit acrs[15] value and shift it by 32. Sick...
 226		 */
 227		if (addr == offsetof(struct user, regs.acrs[15]))
 228			tmp = ((unsigned long) child->thread.acrs[15]) << 32;
 229		else
 230			tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
 231
 232	} else if (addr == offsetof(struct user, regs.orig_gpr2)) {
 233		/*
 234		 * orig_gpr2 is stored on the kernel stack
 235		 */
 236		tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
 237
 238	} else if (addr < offsetof(struct user, regs.fp_regs)) {
 239		/*
 240		 * prevent reads of padding hole between
 241		 * orig_gpr2 and fp_regs on s390.
 242		 */
 243		tmp = 0;
 244
 245	} else if (addr == offsetof(struct user, regs.fp_regs.fpc)) {
 246		/*
 247		 * floating point control reg. is in the thread structure
 248		 */
 249		tmp = child->thread.fpu.fpc;
 250		tmp <<= BITS_PER_LONG - 32;
 251
 252	} else if (addr < offsetof(struct user, regs.fp_regs) + sizeof(s390_fp_regs)) {
 253		/*
 254		 * floating point regs. are either in child->thread.fpu
 255		 * or the child->thread.fpu.vxrs array
 256		 */
 257		offset = addr - offsetof(struct user, regs.fp_regs.fprs);
 258		if (cpu_has_vx())
 259			tmp = *(addr_t *)
 260			       ((addr_t) child->thread.fpu.vxrs + 2*offset);
 261		else
 262			tmp = *(addr_t *)
 263			       ((addr_t) child->thread.fpu.fprs + offset);
 264
 265	} else if (addr < offsetof(struct user, regs.per_info) + sizeof(per_struct)) {
 266		/*
 267		 * Handle access to the per_info structure.
 268		 */
 269		addr -= offsetof(struct user, regs.per_info);
 270		tmp = __peek_user_per(child, addr);
 271
 272	} else
 273		tmp = 0;
 274
 275	return tmp;
 276}
 277
 278static int
 279peek_user(struct task_struct *child, addr_t addr, addr_t data)
 280{
 281	addr_t tmp, mask;
 282
 283	/*
 284	 * Stupid gdb peeks/pokes the access registers in 64 bit with
 285	 * an alignment of 4. Programmers from hell...
 286	 */
 287	mask = __ADDR_MASK;
 288	if (addr >= offsetof(struct user, regs.acrs) &&
 289	    addr < offsetof(struct user, regs.orig_gpr2))
 290		mask = 3;
 291	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 292		return -EIO;
 293
 294	tmp = __peek_user(child, addr);
 295	return put_user(tmp, (addr_t __user *) data);
 296}
 297
 298static inline void __poke_user_per(struct task_struct *child,
 299				   addr_t addr, addr_t data)
 300{
 301	/*
 302	 * There are only three fields in the per_info struct that the
 303	 * debugger user can write to.
 304	 * 1) cr9: the debugger wants to set a new PER event mask
 305	 * 2) starting_addr: the debugger wants to set a new starting
 306	 *    address to use with the PER event mask.
 307	 * 3) ending_addr: the debugger wants to set a new ending
 308	 *    address to use with the PER event mask.
 309	 * The user specified PER event mask and the start and end
 310	 * addresses are used only if single stepping is not in effect.
 311	 * Writes to any other field in per_info are ignored.
 312	 */
 313	if (addr == offsetof(struct per_struct_kernel, cr9))
 314		/* PER event mask of the user specified per set. */
 315		child->thread.per_user.control =
 316			data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 317	else if (addr == offsetof(struct per_struct_kernel, starting_addr))
 318		/* Starting address of the user specified per set. */
 319		child->thread.per_user.start = data;
 320	else if (addr == offsetof(struct per_struct_kernel, ending_addr))
 321		/* Ending address of the user specified per set. */
 322		child->thread.per_user.end = data;
 323}
 324
 325/*
 326 * Write a word to the user area of a process at location addr. This
 327 * operation does have an additional problem compared to peek_user.
 328 * Stores to the program status word and on the floating point
 329 * control register needs to get checked for validity.
 330 */
 331static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 332{
 333	addr_t offset;
 334
 335
 336	if (addr < offsetof(struct user, regs.acrs)) {
 337		struct pt_regs *regs = task_pt_regs(child);
 338		/*
 339		 * psw and gprs are stored on the stack
 340		 */
 341		if (addr == offsetof(struct user, regs.psw.mask)) {
 342			unsigned long mask = PSW_MASK_USER;
 343
 344			mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
 345			if ((data ^ PSW_USER_BITS) & ~mask)
 346				/* Invalid psw mask. */
 347				return -EINVAL;
 348			if ((data & PSW_MASK_ASC) == PSW_ASC_HOME)
 349				/* Invalid address-space-control bits */
 350				return -EINVAL;
 351			if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
 352				/* Invalid addressing mode bits */
 353				return -EINVAL;
 354		}
 355
 356		if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
 357			addr == offsetof(struct user, regs.gprs[2])) {
 358			struct pt_regs *regs = task_pt_regs(child);
 359
 360			regs->int_code = 0x20000 | (data & 0xffff);
 361		}
 362		*(addr_t *)((addr_t) &regs->psw + addr) = data;
 363	} else if (addr < offsetof(struct user, regs.orig_gpr2)) {
 364		/*
 365		 * access registers are stored in the thread structure
 366		 */
 367		offset = addr - offsetof(struct user, regs.acrs);
 368		/*
 369		 * Very special case: old & broken 64 bit gdb writing
 370		 * to acrs[15] with a 64 bit value. Ignore the lower
 371		 * half of the value and write the upper 32 bit to
 372		 * acrs[15]. Sick...
 373		 */
 374		if (addr == offsetof(struct user, regs.acrs[15]))
 375			child->thread.acrs[15] = (unsigned int) (data >> 32);
 376		else
 377			*(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 378
 379	} else if (addr == offsetof(struct user, regs.orig_gpr2)) {
 380		/*
 381		 * orig_gpr2 is stored on the kernel stack
 382		 */
 383		task_pt_regs(child)->orig_gpr2 = data;
 384
 385	} else if (addr < offsetof(struct user, regs.fp_regs)) {
 386		/*
 387		 * prevent writes of padding hole between
 388		 * orig_gpr2 and fp_regs on s390.
 389		 */
 390		return 0;
 391
 392	} else if (addr == offsetof(struct user, regs.fp_regs.fpc)) {
 393		/*
 394		 * floating point control reg. is in the thread structure
 395		 */
 396		if ((unsigned int)data != 0)
 
 397			return -EINVAL;
 398		child->thread.fpu.fpc = data >> (BITS_PER_LONG - 32);
 399
 400	} else if (addr < offsetof(struct user, regs.fp_regs) + sizeof(s390_fp_regs)) {
 401		/*
 402		 * floating point regs. are either in child->thread.fpu
 403		 * or the child->thread.fpu.vxrs array
 404		 */
 405		offset = addr - offsetof(struct user, regs.fp_regs.fprs);
 406		if (cpu_has_vx())
 407			*(addr_t *)((addr_t)
 408				child->thread.fpu.vxrs + 2*offset) = data;
 409		else
 410			*(addr_t *)((addr_t)
 411				child->thread.fpu.fprs + offset) = data;
 412
 413	} else if (addr < offsetof(struct user, regs.per_info) + sizeof(per_struct)) {
 414		/*
 415		 * Handle access to the per_info structure.
 416		 */
 417		addr -= offsetof(struct user, regs.per_info);
 418		__poke_user_per(child, addr, data);
 419
 420	}
 421
 422	return 0;
 423}
 424
 425static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
 426{
 427	addr_t mask;
 428
 429	/*
 430	 * Stupid gdb peeks/pokes the access registers in 64 bit with
 431	 * an alignment of 4. Programmers from hell indeed...
 432	 */
 433	mask = __ADDR_MASK;
 434	if (addr >= offsetof(struct user, regs.acrs) &&
 435	    addr < offsetof(struct user, regs.orig_gpr2))
 436		mask = 3;
 437	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 438		return -EIO;
 439
 440	return __poke_user(child, addr, data);
 441}
 442
 443long arch_ptrace(struct task_struct *child, long request,
 444		 unsigned long addr, unsigned long data)
 445{
 446	ptrace_area parea; 
 447	int copied, ret;
 448
 449	switch (request) {
 450	case PTRACE_PEEKUSR:
 451		/* read the word at location addr in the USER area. */
 452		return peek_user(child, addr, data);
 453
 454	case PTRACE_POKEUSR:
 455		/* write the word at location addr in the USER area */
 456		return poke_user(child, addr, data);
 457
 458	case PTRACE_PEEKUSR_AREA:
 459	case PTRACE_POKEUSR_AREA:
 460		if (copy_from_user(&parea, (void __force __user *) addr,
 461							sizeof(parea)))
 462			return -EFAULT;
 463		addr = parea.kernel_addr;
 464		data = parea.process_addr;
 465		copied = 0;
 466		while (copied < parea.len) {
 467			if (request == PTRACE_PEEKUSR_AREA)
 468				ret = peek_user(child, addr, data);
 469			else {
 470				addr_t utmp;
 471				if (get_user(utmp,
 472					     (addr_t __force __user *) data))
 473					return -EFAULT;
 474				ret = poke_user(child, addr, utmp);
 475			}
 476			if (ret)
 477				return ret;
 478			addr += sizeof(unsigned long);
 479			data += sizeof(unsigned long);
 480			copied += sizeof(unsigned long);
 481		}
 482		return 0;
 483	case PTRACE_GET_LAST_BREAK:
 484		return put_user(child->thread.last_break, (unsigned long __user *)data);
 
 
 485	case PTRACE_ENABLE_TE:
 486		if (!MACHINE_HAS_TE)
 487			return -EIO;
 488		child->thread.per_flags &= ~PER_FLAG_NO_TE;
 489		return 0;
 490	case PTRACE_DISABLE_TE:
 491		if (!MACHINE_HAS_TE)
 492			return -EIO;
 493		child->thread.per_flags |= PER_FLAG_NO_TE;
 494		child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 495		return 0;
 496	case PTRACE_TE_ABORT_RAND:
 497		if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
 498			return -EIO;
 499		switch (data) {
 500		case 0UL:
 501			child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 502			break;
 503		case 1UL:
 504			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 505			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
 506			break;
 507		case 2UL:
 508			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 509			child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
 510			break;
 511		default:
 512			return -EINVAL;
 513		}
 514		return 0;
 515	default:
 516		return ptrace_request(child, request, addr, data);
 517	}
 518}
 519
 520#ifdef CONFIG_COMPAT
 521/*
 522 * Now the fun part starts... a 31 bit program running in the
 523 * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 524 * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 525 * to handle, the difference to the 64 bit versions of the requests
 526 * is that the access is done in multiples of 4 byte instead of
 527 * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 528 * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 529 * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 530 * is a 31 bit program too, the content of struct user can be
 531 * emulated. A 31 bit program peeking into the struct user of
 532 * a 64 bit program is a no-no.
 533 */
 534
 535/*
 536 * Same as peek_user_per but for a 31 bit program.
 537 */
 538static inline __u32 __peek_user_per_compat(struct task_struct *child,
 539					   addr_t addr)
 540{
 541	if (addr == offsetof(struct compat_per_struct_kernel, cr9))
 542		/* Control bits of the active per set. */
 543		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 544			PER_EVENT_IFETCH : child->thread.per_user.control;
 545	else if (addr == offsetof(struct compat_per_struct_kernel, cr10))
 546		/* Start address of the active per set. */
 547		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 548			0 : child->thread.per_user.start;
 549	else if (addr == offsetof(struct compat_per_struct_kernel, cr11))
 550		/* End address of the active per set. */
 551		return test_thread_flag(TIF_SINGLE_STEP) ?
 552			PSW32_ADDR_INSN : child->thread.per_user.end;
 553	else if (addr == offsetof(struct compat_per_struct_kernel, bits))
 554		/* Single-step bit. */
 555		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 556			0x80000000 : 0;
 557	else if (addr == offsetof(struct compat_per_struct_kernel, starting_addr))
 558		/* Start address of the user specified per set. */
 559		return (__u32) child->thread.per_user.start;
 560	else if (addr == offsetof(struct compat_per_struct_kernel, ending_addr))
 561		/* End address of the user specified per set. */
 562		return (__u32) child->thread.per_user.end;
 563	else if (addr == offsetof(struct compat_per_struct_kernel, perc_atmid))
 564		/* PER code, ATMID and AI of the last PER trap */
 565		return (__u32) child->thread.per_event.cause << 16;
 566	else if (addr == offsetof(struct compat_per_struct_kernel, address))
 567		/* Address of the last PER trap */
 568		return (__u32) child->thread.per_event.address;
 569	else if (addr == offsetof(struct compat_per_struct_kernel, access_id))
 570		/* Access id of the last PER trap */
 571		return (__u32) child->thread.per_event.paid << 24;
 572	return 0;
 573}
 574
 575/*
 576 * Same as peek_user but for a 31 bit program.
 577 */
 578static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 579{
 580	addr_t offset;
 581	__u32 tmp;
 582
 583	if (addr < offsetof(struct compat_user, regs.acrs)) {
 584		struct pt_regs *regs = task_pt_regs(child);
 585		/*
 586		 * psw and gprs are stored on the stack
 587		 */
 588		if (addr == offsetof(struct compat_user, regs.psw.mask)) {
 589			/* Fake a 31 bit psw mask. */
 590			tmp = (__u32)(regs->psw.mask >> 32);
 591			tmp &= PSW32_MASK_USER | PSW32_MASK_RI;
 592			tmp |= PSW32_USER_BITS;
 593		} else if (addr == offsetof(struct compat_user, regs.psw.addr)) {
 594			/* Fake a 31 bit psw address. */
 595			tmp = (__u32) regs->psw.addr |
 596				(__u32)(regs->psw.mask & PSW_MASK_BA);
 597		} else {
 598			/* gpr 0-15 */
 599			tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
 600		}
 601	} else if (addr < offsetof(struct compat_user, regs.orig_gpr2)) {
 602		/*
 603		 * access registers are stored in the thread structure
 604		 */
 605		offset = addr - offsetof(struct compat_user, regs.acrs);
 606		tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 607
 608	} else if (addr == offsetof(struct compat_user, regs.orig_gpr2)) {
 609		/*
 610		 * orig_gpr2 is stored on the kernel stack
 611		 */
 612		tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 613
 614	} else if (addr < offsetof(struct compat_user, regs.fp_regs)) {
 615		/*
 616		 * prevent reads of padding hole between
 617		 * orig_gpr2 and fp_regs on s390.
 618		 */
 619		tmp = 0;
 620
 621	} else if (addr == offsetof(struct compat_user, regs.fp_regs.fpc)) {
 622		/*
 623		 * floating point control reg. is in the thread structure
 624		 */
 625		tmp = child->thread.fpu.fpc;
 626
 627	} else if (addr < offsetof(struct compat_user, regs.fp_regs) + sizeof(s390_fp_regs)) {
 628		/*
 629		 * floating point regs. are either in child->thread.fpu
 630		 * or the child->thread.fpu.vxrs array
 631		 */
 632		offset = addr - offsetof(struct compat_user, regs.fp_regs.fprs);
 633		if (cpu_has_vx())
 634			tmp = *(__u32 *)
 635			       ((addr_t) child->thread.fpu.vxrs + 2*offset);
 636		else
 637			tmp = *(__u32 *)
 638			       ((addr_t) child->thread.fpu.fprs + offset);
 639
 640	} else if (addr < offsetof(struct compat_user, regs.per_info) + sizeof(struct compat_per_struct_kernel)) {
 641		/*
 642		 * Handle access to the per_info structure.
 643		 */
 644		addr -= offsetof(struct compat_user, regs.per_info);
 645		tmp = __peek_user_per_compat(child, addr);
 646
 647	} else
 648		tmp = 0;
 649
 650	return tmp;
 651}
 652
 653static int peek_user_compat(struct task_struct *child,
 654			    addr_t addr, addr_t data)
 655{
 656	__u32 tmp;
 657
 658	if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
 659		return -EIO;
 660
 661	tmp = __peek_user_compat(child, addr);
 662	return put_user(tmp, (__u32 __user *) data);
 663}
 664
 665/*
 666 * Same as poke_user_per but for a 31 bit program.
 667 */
 668static inline void __poke_user_per_compat(struct task_struct *child,
 669					  addr_t addr, __u32 data)
 670{
 671	if (addr == offsetof(struct compat_per_struct_kernel, cr9))
 672		/* PER event mask of the user specified per set. */
 673		child->thread.per_user.control =
 674			data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 675	else if (addr == offsetof(struct compat_per_struct_kernel, starting_addr))
 676		/* Starting address of the user specified per set. */
 677		child->thread.per_user.start = data;
 678	else if (addr == offsetof(struct compat_per_struct_kernel, ending_addr))
 679		/* Ending address of the user specified per set. */
 680		child->thread.per_user.end = data;
 681}
 682
 683/*
 684 * Same as poke_user but for a 31 bit program.
 685 */
 686static int __poke_user_compat(struct task_struct *child,
 687			      addr_t addr, addr_t data)
 688{
 689	__u32 tmp = (__u32) data;
 690	addr_t offset;
 691
 692	if (addr < offsetof(struct compat_user, regs.acrs)) {
 693		struct pt_regs *regs = task_pt_regs(child);
 694		/*
 695		 * psw, gprs, acrs and orig_gpr2 are stored on the stack
 696		 */
 697		if (addr == offsetof(struct compat_user, regs.psw.mask)) {
 698			__u32 mask = PSW32_MASK_USER;
 699
 700			mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
 701			/* Build a 64 bit psw mask from 31 bit mask. */
 702			if ((tmp ^ PSW32_USER_BITS) & ~mask)
 703				/* Invalid psw mask. */
 704				return -EINVAL;
 705			if ((data & PSW32_MASK_ASC) == PSW32_ASC_HOME)
 706				/* Invalid address-space-control bits */
 707				return -EINVAL;
 708			regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
 709				(regs->psw.mask & PSW_MASK_BA) |
 710				(__u64)(tmp & mask) << 32;
 711		} else if (addr == offsetof(struct compat_user, regs.psw.addr)) {
 712			/* Build a 64 bit psw address from 31 bit address. */
 713			regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
 714			/* Transfer 31 bit amode bit to psw mask. */
 715			regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
 716				(__u64)(tmp & PSW32_ADDR_AMODE);
 717		} else {
 718			if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
 719				addr == offsetof(struct compat_user, regs.gprs[2])) {
 720				struct pt_regs *regs = task_pt_regs(child);
 721
 722				regs->int_code = 0x20000 | (data & 0xffff);
 723			}
 724			/* gpr 0-15 */
 725			*(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
 726		}
 727	} else if (addr < offsetof(struct compat_user, regs.orig_gpr2)) {
 728		/*
 729		 * access registers are stored in the thread structure
 730		 */
 731		offset = addr - offsetof(struct compat_user, regs.acrs);
 732		*(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 733
 734	} else if (addr == offsetof(struct compat_user, regs.orig_gpr2)) {
 735		/*
 736		 * orig_gpr2 is stored on the kernel stack
 737		 */
 738		*(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 739
 740	} else if (addr < offsetof(struct compat_user, regs.fp_regs)) {
 741		/*
 742		 * prevent writess of padding hole between
 743		 * orig_gpr2 and fp_regs on s390.
 744		 */
 745		return 0;
 746
 747	} else if (addr == offsetof(struct compat_user, regs.fp_regs.fpc)) {
 748		/*
 749		 * floating point control reg. is in the thread structure
 750		 */
 
 
 751		child->thread.fpu.fpc = data;
 752
 753	} else if (addr < offsetof(struct compat_user, regs.fp_regs) + sizeof(s390_fp_regs)) {
 754		/*
 755		 * floating point regs. are either in child->thread.fpu
 756		 * or the child->thread.fpu.vxrs array
 757		 */
 758		offset = addr - offsetof(struct compat_user, regs.fp_regs.fprs);
 759		if (cpu_has_vx())
 760			*(__u32 *)((addr_t)
 761				child->thread.fpu.vxrs + 2*offset) = tmp;
 762		else
 763			*(__u32 *)((addr_t)
 764				child->thread.fpu.fprs + offset) = tmp;
 765
 766	} else if (addr < offsetof(struct compat_user, regs.per_info) + sizeof(struct compat_per_struct_kernel)) {
 767		/*
 768		 * Handle access to the per_info structure.
 769		 */
 770		addr -= offsetof(struct compat_user, regs.per_info);
 771		__poke_user_per_compat(child, addr, data);
 772	}
 773
 774	return 0;
 775}
 776
 777static int poke_user_compat(struct task_struct *child,
 778			    addr_t addr, addr_t data)
 779{
 780	if (!is_compat_task() || (addr & 3) ||
 781	    addr > sizeof(struct compat_user) - 3)
 782		return -EIO;
 783
 784	return __poke_user_compat(child, addr, data);
 785}
 786
 787long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 788			compat_ulong_t caddr, compat_ulong_t cdata)
 789{
 790	unsigned long addr = caddr;
 791	unsigned long data = cdata;
 792	compat_ptrace_area parea;
 793	int copied, ret;
 794
 795	switch (request) {
 796	case PTRACE_PEEKUSR:
 797		/* read the word at location addr in the USER area. */
 798		return peek_user_compat(child, addr, data);
 799
 800	case PTRACE_POKEUSR:
 801		/* write the word at location addr in the USER area */
 802		return poke_user_compat(child, addr, data);
 803
 804	case PTRACE_PEEKUSR_AREA:
 805	case PTRACE_POKEUSR_AREA:
 806		if (copy_from_user(&parea, (void __force __user *) addr,
 807							sizeof(parea)))
 808			return -EFAULT;
 809		addr = parea.kernel_addr;
 810		data = parea.process_addr;
 811		copied = 0;
 812		while (copied < parea.len) {
 813			if (request == PTRACE_PEEKUSR_AREA)
 814				ret = peek_user_compat(child, addr, data);
 815			else {
 816				__u32 utmp;
 817				if (get_user(utmp,
 818					     (__u32 __force __user *) data))
 819					return -EFAULT;
 820				ret = poke_user_compat(child, addr, utmp);
 821			}
 822			if (ret)
 823				return ret;
 824			addr += sizeof(unsigned int);
 825			data += sizeof(unsigned int);
 826			copied += sizeof(unsigned int);
 827		}
 828		return 0;
 829	case PTRACE_GET_LAST_BREAK:
 830		return put_user(child->thread.last_break, (unsigned int __user *)data);
 
 
 831	}
 832	return compat_ptrace_request(child, request, addr, data);
 833}
 834#endif
 835
 836/*
 837 * user_regset definitions.
 838 */
 839
 840static int s390_regs_get(struct task_struct *target,
 841			 const struct user_regset *regset,
 842			 struct membuf to)
 843{
 844	unsigned pos;
 845	if (target == current)
 846		save_access_regs(target->thread.acrs);
 847
 848	for (pos = 0; pos < sizeof(s390_regs); pos += sizeof(long))
 849		membuf_store(&to, __peek_user(target, pos));
 850	return 0;
 851}
 852
 853static int s390_regs_set(struct task_struct *target,
 854			 const struct user_regset *regset,
 855			 unsigned int pos, unsigned int count,
 856			 const void *kbuf, const void __user *ubuf)
 857{
 858	int rc = 0;
 859
 860	if (target == current)
 861		save_access_regs(target->thread.acrs);
 862
 863	if (kbuf) {
 864		const unsigned long *k = kbuf;
 865		while (count > 0 && !rc) {
 866			rc = __poke_user(target, pos, *k++);
 867			count -= sizeof(*k);
 868			pos += sizeof(*k);
 869		}
 870	} else {
 871		const unsigned long  __user *u = ubuf;
 872		while (count > 0 && !rc) {
 873			unsigned long word;
 874			rc = __get_user(word, u++);
 875			if (rc)
 876				break;
 877			rc = __poke_user(target, pos, word);
 878			count -= sizeof(*u);
 879			pos += sizeof(*u);
 880		}
 881	}
 882
 883	if (rc == 0 && target == current)
 884		restore_access_regs(target->thread.acrs);
 885
 886	return rc;
 887}
 888
 889static int s390_fpregs_get(struct task_struct *target,
 890			   const struct user_regset *regset,
 891			   struct membuf to)
 892{
 893	_s390_fp_regs fp_regs;
 894
 895	if (target == current)
 896		save_fpu_regs();
 897
 898	fp_regs.fpc = target->thread.fpu.fpc;
 899	fpregs_store(&fp_regs, &target->thread.fpu);
 900
 901	return membuf_write(&to, &fp_regs, sizeof(fp_regs));
 902}
 903
 904static int s390_fpregs_set(struct task_struct *target,
 905			   const struct user_regset *regset, unsigned int pos,
 906			   unsigned int count, const void *kbuf,
 907			   const void __user *ubuf)
 908{
 909	int rc = 0;
 910	freg_t fprs[__NUM_FPRS];
 911
 912	if (target == current)
 913		save_fpu_regs();
 914
 915	if (cpu_has_vx())
 916		convert_vx_to_fp(fprs, target->thread.fpu.vxrs);
 917	else
 918		memcpy(&fprs, target->thread.fpu.fprs, sizeof(fprs));
 919
 
 920	if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 921		u32 ufpc[2] = { target->thread.fpu.fpc, 0 };
 922		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
 923					0, offsetof(s390_fp_regs, fprs));
 924		if (rc)
 925			return rc;
 926		if (ufpc[1] != 0)
 927			return -EINVAL;
 928		target->thread.fpu.fpc = ufpc[0];
 929	}
 930
 931	if (rc == 0 && count > 0)
 932		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 933					fprs, offsetof(s390_fp_regs, fprs), -1);
 934	if (rc)
 935		return rc;
 936
 937	if (cpu_has_vx())
 938		convert_fp_to_vx(target->thread.fpu.vxrs, fprs);
 939	else
 940		memcpy(target->thread.fpu.fprs, &fprs, sizeof(fprs));
 941
 942	return rc;
 943}
 944
 945static int s390_last_break_get(struct task_struct *target,
 946			       const struct user_regset *regset,
 947			       struct membuf to)
 948{
 949	return membuf_store(&to, target->thread.last_break);
 950}
 951
 952static int s390_last_break_set(struct task_struct *target,
 953			       const struct user_regset *regset,
 954			       unsigned int pos, unsigned int count,
 955			       const void *kbuf, const void __user *ubuf)
 956{
 957	return 0;
 958}
 959
 960static int s390_tdb_get(struct task_struct *target,
 961			const struct user_regset *regset,
 962			struct membuf to)
 963{
 964	struct pt_regs *regs = task_pt_regs(target);
 965	size_t size;
 966
 967	if (!(regs->int_code & 0x200))
 968		return -ENODATA;
 969	size = sizeof(target->thread.trap_tdb.data);
 970	return membuf_write(&to, target->thread.trap_tdb.data, size);
 971}
 972
 973static int s390_tdb_set(struct task_struct *target,
 974			const struct user_regset *regset,
 975			unsigned int pos, unsigned int count,
 976			const void *kbuf, const void __user *ubuf)
 977{
 978	return 0;
 979}
 980
 981static int s390_vxrs_low_get(struct task_struct *target,
 982			     const struct user_regset *regset,
 983			     struct membuf to)
 984{
 985	__u64 vxrs[__NUM_VXRS_LOW];
 986	int i;
 987
 988	if (!cpu_has_vx())
 989		return -ENODEV;
 990	if (target == current)
 991		save_fpu_regs();
 992	for (i = 0; i < __NUM_VXRS_LOW; i++)
 993		vxrs[i] = target->thread.fpu.vxrs[i].low;
 994	return membuf_write(&to, vxrs, sizeof(vxrs));
 995}
 996
 997static int s390_vxrs_low_set(struct task_struct *target,
 998			     const struct user_regset *regset,
 999			     unsigned int pos, unsigned int count,
1000			     const void *kbuf, const void __user *ubuf)
1001{
1002	__u64 vxrs[__NUM_VXRS_LOW];
1003	int i, rc;
1004
1005	if (!cpu_has_vx())
1006		return -ENODEV;
1007	if (target == current)
1008		save_fpu_regs();
1009
1010	for (i = 0; i < __NUM_VXRS_LOW; i++)
1011		vxrs[i] = target->thread.fpu.vxrs[i].low;
1012
1013	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1014	if (rc == 0)
1015		for (i = 0; i < __NUM_VXRS_LOW; i++)
1016			target->thread.fpu.vxrs[i].low = vxrs[i];
1017
1018	return rc;
1019}
1020
1021static int s390_vxrs_high_get(struct task_struct *target,
1022			      const struct user_regset *regset,
1023			      struct membuf to)
1024{
1025	if (!cpu_has_vx())
1026		return -ENODEV;
1027	if (target == current)
1028		save_fpu_regs();
1029	return membuf_write(&to, target->thread.fpu.vxrs + __NUM_VXRS_LOW,
1030			    __NUM_VXRS_HIGH * sizeof(__vector128));
1031}
1032
1033static int s390_vxrs_high_set(struct task_struct *target,
1034			      const struct user_regset *regset,
1035			      unsigned int pos, unsigned int count,
1036			      const void *kbuf, const void __user *ubuf)
1037{
1038	int rc;
1039
1040	if (!cpu_has_vx())
1041		return -ENODEV;
1042	if (target == current)
1043		save_fpu_regs();
1044
1045	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1046				target->thread.fpu.vxrs + __NUM_VXRS_LOW, 0, -1);
1047	return rc;
1048}
1049
1050static int s390_system_call_get(struct task_struct *target,
1051				const struct user_regset *regset,
1052				struct membuf to)
1053{
1054	return membuf_store(&to, target->thread.system_call);
1055}
1056
1057static int s390_system_call_set(struct task_struct *target,
1058				const struct user_regset *regset,
1059				unsigned int pos, unsigned int count,
1060				const void *kbuf, const void __user *ubuf)
1061{
1062	unsigned int *data = &target->thread.system_call;
1063	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1064				  data, 0, sizeof(unsigned int));
1065}
1066
1067static int s390_gs_cb_get(struct task_struct *target,
1068			  const struct user_regset *regset,
1069			  struct membuf to)
1070{
1071	struct gs_cb *data = target->thread.gs_cb;
1072
1073	if (!MACHINE_HAS_GS)
1074		return -ENODEV;
1075	if (!data)
1076		return -ENODATA;
1077	if (target == current)
1078		save_gs_cb(data);
1079	return membuf_write(&to, data, sizeof(struct gs_cb));
1080}
1081
1082static int s390_gs_cb_set(struct task_struct *target,
1083			  const struct user_regset *regset,
1084			  unsigned int pos, unsigned int count,
1085			  const void *kbuf, const void __user *ubuf)
1086{
1087	struct gs_cb gs_cb = { }, *data = NULL;
1088	int rc;
1089
1090	if (!MACHINE_HAS_GS)
1091		return -ENODEV;
1092	if (!target->thread.gs_cb) {
1093		data = kzalloc(sizeof(*data), GFP_KERNEL);
1094		if (!data)
1095			return -ENOMEM;
1096	}
1097	if (!target->thread.gs_cb)
1098		gs_cb.gsd = 25;
1099	else if (target == current)
1100		save_gs_cb(&gs_cb);
1101	else
1102		gs_cb = *target->thread.gs_cb;
1103	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1104				&gs_cb, 0, sizeof(gs_cb));
1105	if (rc) {
1106		kfree(data);
1107		return -EFAULT;
1108	}
1109	preempt_disable();
1110	if (!target->thread.gs_cb)
1111		target->thread.gs_cb = data;
1112	*target->thread.gs_cb = gs_cb;
1113	if (target == current) {
1114		local_ctl_set_bit(2, CR2_GUARDED_STORAGE_BIT);
1115		restore_gs_cb(target->thread.gs_cb);
1116	}
1117	preempt_enable();
1118	return rc;
1119}
1120
1121static int s390_gs_bc_get(struct task_struct *target,
1122			  const struct user_regset *regset,
1123			  struct membuf to)
1124{
1125	struct gs_cb *data = target->thread.gs_bc_cb;
1126
1127	if (!MACHINE_HAS_GS)
1128		return -ENODEV;
1129	if (!data)
1130		return -ENODATA;
1131	return membuf_write(&to, data, sizeof(struct gs_cb));
1132}
1133
1134static int s390_gs_bc_set(struct task_struct *target,
1135			  const struct user_regset *regset,
1136			  unsigned int pos, unsigned int count,
1137			  const void *kbuf, const void __user *ubuf)
1138{
1139	struct gs_cb *data = target->thread.gs_bc_cb;
1140
1141	if (!MACHINE_HAS_GS)
1142		return -ENODEV;
1143	if (!data) {
1144		data = kzalloc(sizeof(*data), GFP_KERNEL);
1145		if (!data)
1146			return -ENOMEM;
1147		target->thread.gs_bc_cb = data;
1148	}
1149	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1150				  data, 0, sizeof(struct gs_cb));
1151}
1152
1153static bool is_ri_cb_valid(struct runtime_instr_cb *cb)
1154{
1155	return (cb->rca & 0x1f) == 0 &&
1156		(cb->roa & 0xfff) == 0 &&
1157		(cb->rla & 0xfff) == 0xfff &&
1158		cb->s == 1 &&
1159		cb->k == 1 &&
1160		cb->h == 0 &&
1161		cb->reserved1 == 0 &&
1162		cb->ps == 1 &&
1163		cb->qs == 0 &&
1164		cb->pc == 1 &&
1165		cb->qc == 0 &&
1166		cb->reserved2 == 0 &&
1167		cb->reserved3 == 0 &&
1168		cb->reserved4 == 0 &&
1169		cb->reserved5 == 0 &&
1170		cb->reserved6 == 0 &&
1171		cb->reserved7 == 0 &&
1172		cb->reserved8 == 0 &&
1173		cb->rla >= cb->roa &&
1174		cb->rca >= cb->roa &&
1175		cb->rca <= cb->rla+1 &&
1176		cb->m < 3;
1177}
1178
1179static int s390_runtime_instr_get(struct task_struct *target,
1180				const struct user_regset *regset,
1181				struct membuf to)
1182{
1183	struct runtime_instr_cb *data = target->thread.ri_cb;
1184
1185	if (!test_facility(64))
1186		return -ENODEV;
1187	if (!data)
1188		return -ENODATA;
1189
1190	return membuf_write(&to, data, sizeof(struct runtime_instr_cb));
1191}
1192
1193static int s390_runtime_instr_set(struct task_struct *target,
1194				  const struct user_regset *regset,
1195				  unsigned int pos, unsigned int count,
1196				  const void *kbuf, const void __user *ubuf)
1197{
1198	struct runtime_instr_cb ri_cb = { }, *data = NULL;
1199	int rc;
1200
1201	if (!test_facility(64))
1202		return -ENODEV;
1203
1204	if (!target->thread.ri_cb) {
1205		data = kzalloc(sizeof(*data), GFP_KERNEL);
1206		if (!data)
1207			return -ENOMEM;
1208	}
1209
1210	if (target->thread.ri_cb) {
1211		if (target == current)
1212			store_runtime_instr_cb(&ri_cb);
1213		else
1214			ri_cb = *target->thread.ri_cb;
1215	}
1216
1217	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1218				&ri_cb, 0, sizeof(struct runtime_instr_cb));
1219	if (rc) {
1220		kfree(data);
1221		return -EFAULT;
1222	}
1223
1224	if (!is_ri_cb_valid(&ri_cb)) {
1225		kfree(data);
1226		return -EINVAL;
1227	}
1228	/*
1229	 * Override access key in any case, since user space should
1230	 * not be able to set it, nor should it care about it.
1231	 */
1232	ri_cb.key = PAGE_DEFAULT_KEY >> 4;
1233	preempt_disable();
1234	if (!target->thread.ri_cb)
1235		target->thread.ri_cb = data;
1236	*target->thread.ri_cb = ri_cb;
1237	if (target == current)
1238		load_runtime_instr_cb(target->thread.ri_cb);
1239	preempt_enable();
1240
1241	return 0;
1242}
1243
1244static const struct user_regset s390_regsets[] = {
1245	{
1246		.core_note_type = NT_PRSTATUS,
1247		.n = sizeof(s390_regs) / sizeof(long),
1248		.size = sizeof(long),
1249		.align = sizeof(long),
1250		.regset_get = s390_regs_get,
1251		.set = s390_regs_set,
1252	},
1253	{
1254		.core_note_type = NT_PRFPREG,
1255		.n = sizeof(s390_fp_regs) / sizeof(long),
1256		.size = sizeof(long),
1257		.align = sizeof(long),
1258		.regset_get = s390_fpregs_get,
1259		.set = s390_fpregs_set,
1260	},
1261	{
1262		.core_note_type = NT_S390_SYSTEM_CALL,
1263		.n = 1,
1264		.size = sizeof(unsigned int),
1265		.align = sizeof(unsigned int),
1266		.regset_get = s390_system_call_get,
1267		.set = s390_system_call_set,
1268	},
1269	{
1270		.core_note_type = NT_S390_LAST_BREAK,
1271		.n = 1,
1272		.size = sizeof(long),
1273		.align = sizeof(long),
1274		.regset_get = s390_last_break_get,
1275		.set = s390_last_break_set,
1276	},
1277	{
1278		.core_note_type = NT_S390_TDB,
1279		.n = 1,
1280		.size = 256,
1281		.align = 1,
1282		.regset_get = s390_tdb_get,
1283		.set = s390_tdb_set,
1284	},
1285	{
1286		.core_note_type = NT_S390_VXRS_LOW,
1287		.n = __NUM_VXRS_LOW,
1288		.size = sizeof(__u64),
1289		.align = sizeof(__u64),
1290		.regset_get = s390_vxrs_low_get,
1291		.set = s390_vxrs_low_set,
1292	},
1293	{
1294		.core_note_type = NT_S390_VXRS_HIGH,
1295		.n = __NUM_VXRS_HIGH,
1296		.size = sizeof(__vector128),
1297		.align = sizeof(__vector128),
1298		.regset_get = s390_vxrs_high_get,
1299		.set = s390_vxrs_high_set,
1300	},
1301	{
1302		.core_note_type = NT_S390_GS_CB,
1303		.n = sizeof(struct gs_cb) / sizeof(__u64),
1304		.size = sizeof(__u64),
1305		.align = sizeof(__u64),
1306		.regset_get = s390_gs_cb_get,
1307		.set = s390_gs_cb_set,
1308	},
1309	{
1310		.core_note_type = NT_S390_GS_BC,
1311		.n = sizeof(struct gs_cb) / sizeof(__u64),
1312		.size = sizeof(__u64),
1313		.align = sizeof(__u64),
1314		.regset_get = s390_gs_bc_get,
1315		.set = s390_gs_bc_set,
1316	},
1317	{
1318		.core_note_type = NT_S390_RI_CB,
1319		.n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1320		.size = sizeof(__u64),
1321		.align = sizeof(__u64),
1322		.regset_get = s390_runtime_instr_get,
1323		.set = s390_runtime_instr_set,
1324	},
1325};
1326
1327static const struct user_regset_view user_s390_view = {
1328	.name = "s390x",
1329	.e_machine = EM_S390,
1330	.regsets = s390_regsets,
1331	.n = ARRAY_SIZE(s390_regsets)
1332};
1333
1334#ifdef CONFIG_COMPAT
1335static int s390_compat_regs_get(struct task_struct *target,
1336				const struct user_regset *regset,
1337				struct membuf to)
1338{
1339	unsigned n;
1340
1341	if (target == current)
1342		save_access_regs(target->thread.acrs);
1343
1344	for (n = 0; n < sizeof(s390_compat_regs); n += sizeof(compat_ulong_t))
1345		membuf_store(&to, __peek_user_compat(target, n));
1346	return 0;
1347}
1348
1349static int s390_compat_regs_set(struct task_struct *target,
1350				const struct user_regset *regset,
1351				unsigned int pos, unsigned int count,
1352				const void *kbuf, const void __user *ubuf)
1353{
1354	int rc = 0;
1355
1356	if (target == current)
1357		save_access_regs(target->thread.acrs);
1358
1359	if (kbuf) {
1360		const compat_ulong_t *k = kbuf;
1361		while (count > 0 && !rc) {
1362			rc = __poke_user_compat(target, pos, *k++);
1363			count -= sizeof(*k);
1364			pos += sizeof(*k);
1365		}
1366	} else {
1367		const compat_ulong_t  __user *u = ubuf;
1368		while (count > 0 && !rc) {
1369			compat_ulong_t word;
1370			rc = __get_user(word, u++);
1371			if (rc)
1372				break;
1373			rc = __poke_user_compat(target, pos, word);
1374			count -= sizeof(*u);
1375			pos += sizeof(*u);
1376		}
1377	}
1378
1379	if (rc == 0 && target == current)
1380		restore_access_regs(target->thread.acrs);
1381
1382	return rc;
1383}
1384
1385static int s390_compat_regs_high_get(struct task_struct *target,
1386				     const struct user_regset *regset,
1387				     struct membuf to)
1388{
1389	compat_ulong_t *gprs_high;
1390	int i;
1391
1392	gprs_high = (compat_ulong_t *)task_pt_regs(target)->gprs;
1393	for (i = 0; i < NUM_GPRS; i++, gprs_high += 2)
1394		membuf_store(&to, *gprs_high);
1395	return 0;
1396}
1397
1398static int s390_compat_regs_high_set(struct task_struct *target,
1399				     const struct user_regset *regset,
1400				     unsigned int pos, unsigned int count,
1401				     const void *kbuf, const void __user *ubuf)
1402{
1403	compat_ulong_t *gprs_high;
1404	int rc = 0;
1405
1406	gprs_high = (compat_ulong_t *)
1407		&task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1408	if (kbuf) {
1409		const compat_ulong_t *k = kbuf;
1410		while (count > 0) {
1411			*gprs_high = *k++;
1412			*gprs_high += 2;
1413			count -= sizeof(*k);
1414		}
1415	} else {
1416		const compat_ulong_t  __user *u = ubuf;
1417		while (count > 0 && !rc) {
1418			unsigned long word;
1419			rc = __get_user(word, u++);
1420			if (rc)
1421				break;
1422			*gprs_high = word;
1423			*gprs_high += 2;
1424			count -= sizeof(*u);
1425		}
1426	}
1427
1428	return rc;
1429}
1430
1431static int s390_compat_last_break_get(struct task_struct *target,
1432				      const struct user_regset *regset,
1433				      struct membuf to)
1434{
1435	compat_ulong_t last_break = target->thread.last_break;
1436
1437	return membuf_store(&to, (unsigned long)last_break);
1438}
1439
1440static int s390_compat_last_break_set(struct task_struct *target,
1441				      const struct user_regset *regset,
1442				      unsigned int pos, unsigned int count,
1443				      const void *kbuf, const void __user *ubuf)
1444{
1445	return 0;
1446}
1447
1448static const struct user_regset s390_compat_regsets[] = {
1449	{
1450		.core_note_type = NT_PRSTATUS,
1451		.n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1452		.size = sizeof(compat_long_t),
1453		.align = sizeof(compat_long_t),
1454		.regset_get = s390_compat_regs_get,
1455		.set = s390_compat_regs_set,
1456	},
1457	{
1458		.core_note_type = NT_PRFPREG,
1459		.n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1460		.size = sizeof(compat_long_t),
1461		.align = sizeof(compat_long_t),
1462		.regset_get = s390_fpregs_get,
1463		.set = s390_fpregs_set,
1464	},
1465	{
1466		.core_note_type = NT_S390_SYSTEM_CALL,
1467		.n = 1,
1468		.size = sizeof(compat_uint_t),
1469		.align = sizeof(compat_uint_t),
1470		.regset_get = s390_system_call_get,
1471		.set = s390_system_call_set,
1472	},
1473	{
1474		.core_note_type = NT_S390_LAST_BREAK,
1475		.n = 1,
1476		.size = sizeof(long),
1477		.align = sizeof(long),
1478		.regset_get = s390_compat_last_break_get,
1479		.set = s390_compat_last_break_set,
1480	},
1481	{
1482		.core_note_type = NT_S390_TDB,
1483		.n = 1,
1484		.size = 256,
1485		.align = 1,
1486		.regset_get = s390_tdb_get,
1487		.set = s390_tdb_set,
1488	},
1489	{
1490		.core_note_type = NT_S390_VXRS_LOW,
1491		.n = __NUM_VXRS_LOW,
1492		.size = sizeof(__u64),
1493		.align = sizeof(__u64),
1494		.regset_get = s390_vxrs_low_get,
1495		.set = s390_vxrs_low_set,
1496	},
1497	{
1498		.core_note_type = NT_S390_VXRS_HIGH,
1499		.n = __NUM_VXRS_HIGH,
1500		.size = sizeof(__vector128),
1501		.align = sizeof(__vector128),
1502		.regset_get = s390_vxrs_high_get,
1503		.set = s390_vxrs_high_set,
1504	},
1505	{
1506		.core_note_type = NT_S390_HIGH_GPRS,
1507		.n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1508		.size = sizeof(compat_long_t),
1509		.align = sizeof(compat_long_t),
1510		.regset_get = s390_compat_regs_high_get,
1511		.set = s390_compat_regs_high_set,
1512	},
1513	{
1514		.core_note_type = NT_S390_GS_CB,
1515		.n = sizeof(struct gs_cb) / sizeof(__u64),
1516		.size = sizeof(__u64),
1517		.align = sizeof(__u64),
1518		.regset_get = s390_gs_cb_get,
1519		.set = s390_gs_cb_set,
1520	},
1521	{
1522		.core_note_type = NT_S390_GS_BC,
1523		.n = sizeof(struct gs_cb) / sizeof(__u64),
1524		.size = sizeof(__u64),
1525		.align = sizeof(__u64),
1526		.regset_get = s390_gs_bc_get,
1527		.set = s390_gs_bc_set,
1528	},
1529	{
1530		.core_note_type = NT_S390_RI_CB,
1531		.n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1532		.size = sizeof(__u64),
1533		.align = sizeof(__u64),
1534		.regset_get = s390_runtime_instr_get,
1535		.set = s390_runtime_instr_set,
1536	},
1537};
1538
1539static const struct user_regset_view user_s390_compat_view = {
1540	.name = "s390",
1541	.e_machine = EM_S390,
1542	.regsets = s390_compat_regsets,
1543	.n = ARRAY_SIZE(s390_compat_regsets)
1544};
1545#endif
1546
1547const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1548{
1549#ifdef CONFIG_COMPAT
1550	if (test_tsk_thread_flag(task, TIF_31BIT))
1551		return &user_s390_compat_view;
1552#endif
1553	return &user_s390_view;
1554}
1555
1556static const char *gpr_names[NUM_GPRS] = {
1557	"r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1558	"r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1559};
1560
1561unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1562{
1563	if (offset >= NUM_GPRS)
1564		return 0;
1565	return regs->gprs[offset];
1566}
1567
1568int regs_query_register_offset(const char *name)
1569{
1570	unsigned long offset;
1571
1572	if (!name || *name != 'r')
1573		return -EINVAL;
1574	if (kstrtoul(name + 1, 10, &offset))
1575		return -EINVAL;
1576	if (offset >= NUM_GPRS)
1577		return -EINVAL;
1578	return offset;
1579}
1580
1581const char *regs_query_register_name(unsigned int offset)
1582{
1583	if (offset >= NUM_GPRS)
1584		return NULL;
1585	return gpr_names[offset];
1586}
1587
1588static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1589{
1590	unsigned long ksp = kernel_stack_pointer(regs);
1591
1592	return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1593}
1594
1595/**
1596 * regs_get_kernel_stack_nth() - get Nth entry of the stack
1597 * @regs:pt_regs which contains kernel stack pointer.
1598 * @n:stack entry number.
1599 *
1600 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1601 * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1602 * this returns 0.
1603 */
1604unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1605{
1606	unsigned long addr;
1607
1608	addr = kernel_stack_pointer(regs) + n * sizeof(long);
1609	if (!regs_within_kernel_stack(regs, addr))
1610		return 0;
1611	return *(unsigned long *)addr;
1612}