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v6.13.7
   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/guarded_storage.h>
  28#include <asm/access-regs.h>
  29#include <asm/page.h>
  30#include <linux/uaccess.h>
  31#include <asm/unistd.h>
 
  32#include <asm/runtime_instr.h>
  33#include <asm/facility.h>
  34#include <asm/fpu.h>
  35
  36#include "entry.h"
  37
  38#ifdef CONFIG_COMPAT
  39#include "compat_ptrace.h"
  40#endif
  41
  42void update_cr_regs(struct task_struct *task)
  43{
  44	struct pt_regs *regs = task_pt_regs(task);
  45	struct thread_struct *thread = &task->thread;
 
  46	union ctlreg0 cr0_old, cr0_new;
  47	union ctlreg2 cr2_old, cr2_new;
  48	int cr0_changed, cr2_changed;
  49	union {
  50		struct ctlreg regs[3];
  51		struct {
  52			struct ctlreg control;
  53			struct ctlreg start;
  54			struct ctlreg end;
  55		};
  56	} old, new;
  57
  58	local_ctl_store(0, &cr0_old.reg);
  59	local_ctl_store(2, &cr2_old.reg);
  60	cr0_new = cr0_old;
  61	cr2_new = cr2_old;
  62	/* Take care of the enable/disable of transactional execution. */
  63	if (MACHINE_HAS_TE) {
  64		/* Set or clear transaction execution TXC bit 8. */
  65		cr0_new.tcx = 1;
  66		if (task->thread.per_flags & PER_FLAG_NO_TE)
  67			cr0_new.tcx = 0;
  68		/* Set or clear transaction execution TDC bits 62 and 63. */
  69		cr2_new.tdc = 0;
  70		if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
  71			if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND_TEND)
  72				cr2_new.tdc = 1;
  73			else
  74				cr2_new.tdc = 2;
  75		}
  76	}
  77	/* Take care of enable/disable of guarded storage. */
  78	if (MACHINE_HAS_GS) {
  79		cr2_new.gse = 0;
  80		if (task->thread.gs_cb)
  81			cr2_new.gse = 1;
  82	}
  83	/* Load control register 0/2 iff changed */
  84	cr0_changed = cr0_new.val != cr0_old.val;
  85	cr2_changed = cr2_new.val != cr2_old.val;
  86	if (cr0_changed)
  87		local_ctl_load(0, &cr0_new.reg);
  88	if (cr2_changed)
  89		local_ctl_load(2, &cr2_new.reg);
  90	/* Copy user specified PER registers */
  91	new.control.val = thread->per_user.control;
  92	new.start.val = thread->per_user.start;
  93	new.end.val = thread->per_user.end;
  94
  95	/* merge TIF_SINGLE_STEP into user specified PER registers. */
  96	if (test_tsk_thread_flag(task, TIF_SINGLE_STEP) ||
  97	    test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP)) {
  98		if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))
  99			new.control.val |= PER_EVENT_BRANCH;
 100		else
 101			new.control.val |= PER_EVENT_IFETCH;
 102		new.control.val |= PER_CONTROL_SUSPENSION;
 103		new.control.val |= PER_EVENT_TRANSACTION_END;
 104		if (test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP))
 105			new.control.val |= PER_EVENT_IFETCH;
 106		new.start.val = 0;
 107		new.end.val = -1UL;
 108	}
 109
 110	/* Take care of the PER enablement bit in the PSW. */
 111	if (!(new.control.val & PER_EVENT_MASK)) {
 112		regs->psw.mask &= ~PSW_MASK_PER;
 113		return;
 114	}
 115	regs->psw.mask |= PSW_MASK_PER;
 116	__local_ctl_store(9, 11, old.regs);
 117	if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
 118		__local_ctl_load(9, 11, new.regs);
 119}
 120
 121void user_enable_single_step(struct task_struct *task)
 122{
 123	clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
 124	set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 125}
 126
 127void user_disable_single_step(struct task_struct *task)
 128{
 129	clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
 130	clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 131}
 132
 133void user_enable_block_step(struct task_struct *task)
 134{
 135	set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 136	set_tsk_thread_flag(task, TIF_BLOCK_STEP);
 137}
 138
 139/*
 140 * Called by kernel/ptrace.c when detaching..
 141 *
 142 * Clear all debugging related fields.
 143 */
 144void ptrace_disable(struct task_struct *task)
 145{
 146	memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
 147	memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
 148	clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 149	clear_tsk_thread_flag(task, TIF_PER_TRAP);
 150	task->thread.per_flags = 0;
 151}
 152
 153#define __ADDR_MASK 7
 154
 155static inline unsigned long __peek_user_per(struct task_struct *child,
 156					    addr_t addr)
 157{
 158	if (addr == offsetof(struct per_struct_kernel, cr9))
 
 
 159		/* Control bits of the active per set. */
 160		return test_thread_flag(TIF_SINGLE_STEP) ?
 161			PER_EVENT_IFETCH : child->thread.per_user.control;
 162	else if (addr == offsetof(struct per_struct_kernel, cr10))
 163		/* Start address of the active per set. */
 164		return test_thread_flag(TIF_SINGLE_STEP) ?
 165			0 : child->thread.per_user.start;
 166	else if (addr == offsetof(struct per_struct_kernel, cr11))
 167		/* End address of the active per set. */
 168		return test_thread_flag(TIF_SINGLE_STEP) ?
 169			-1UL : child->thread.per_user.end;
 170	else if (addr == offsetof(struct per_struct_kernel, bits))
 171		/* Single-step bit. */
 172		return test_thread_flag(TIF_SINGLE_STEP) ?
 173			(1UL << (BITS_PER_LONG - 1)) : 0;
 174	else if (addr == offsetof(struct per_struct_kernel, starting_addr))
 175		/* Start address of the user specified per set. */
 176		return child->thread.per_user.start;
 177	else if (addr == offsetof(struct per_struct_kernel, ending_addr))
 178		/* End address of the user specified per set. */
 179		return child->thread.per_user.end;
 180	else if (addr == offsetof(struct per_struct_kernel, perc_atmid))
 181		/* PER code, ATMID and AI of the last PER trap */
 182		return (unsigned long)
 183			child->thread.per_event.cause << (BITS_PER_LONG - 16);
 184	else if (addr == offsetof(struct per_struct_kernel, address))
 185		/* Address of the last PER trap */
 186		return child->thread.per_event.address;
 187	else if (addr == offsetof(struct per_struct_kernel, access_id))
 188		/* Access id of the last PER trap */
 189		return (unsigned long)
 190			child->thread.per_event.paid << (BITS_PER_LONG - 8);
 191	return 0;
 192}
 193
 194/*
 195 * Read the word at offset addr from the user area of a process. The
 196 * trouble here is that the information is littered over different
 197 * locations. The process registers are found on the kernel stack,
 198 * the floating point stuff and the trace settings are stored in
 199 * the task structure. In addition the different structures in
 200 * struct user contain pad bytes that should be read as zeroes.
 201 * Lovely...
 202 */
 203static unsigned long __peek_user(struct task_struct *child, addr_t addr)
 204{
 
 205	addr_t offset, tmp;
 206
 207	if (addr < offsetof(struct user, regs.acrs)) {
 208		/*
 209		 * psw and gprs are stored on the stack
 210		 */
 211		tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
 212		if (addr == offsetof(struct user, regs.psw.mask)) {
 213			/* Return a clean psw mask. */
 214			tmp &= PSW_MASK_USER | PSW_MASK_RI;
 215			tmp |= PSW_USER_BITS;
 216		}
 217
 218	} else if (addr < offsetof(struct user, regs.orig_gpr2)) {
 219		/*
 220		 * access registers are stored in the thread structure
 221		 */
 222		offset = addr - offsetof(struct user, regs.acrs);
 223		/*
 224		 * Very special case: old & broken 64 bit gdb reading
 225		 * from acrs[15]. Result is a 64 bit value. Read the
 226		 * 32 bit acrs[15] value and shift it by 32. Sick...
 227		 */
 228		if (addr == offsetof(struct user, regs.acrs[15]))
 229			tmp = ((unsigned long) child->thread.acrs[15]) << 32;
 230		else
 231			tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
 232
 233	} else if (addr == offsetof(struct user, regs.orig_gpr2)) {
 234		/*
 235		 * orig_gpr2 is stored on the kernel stack
 236		 */
 237		tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
 238
 239	} else if (addr < offsetof(struct user, regs.fp_regs)) {
 240		/*
 241		 * prevent reads of padding hole between
 242		 * orig_gpr2 and fp_regs on s390.
 243		 */
 244		tmp = 0;
 245
 246	} else if (addr == offsetof(struct user, regs.fp_regs.fpc)) {
 247		/*
 248		 * floating point control reg. is in the thread structure
 249		 */
 250		tmp = child->thread.ufpu.fpc;
 251		tmp <<= BITS_PER_LONG - 32;
 252
 253	} else if (addr < offsetof(struct user, regs.fp_regs) + sizeof(s390_fp_regs)) {
 254		/*
 255		 * floating point regs. are in the child->thread.ufpu.vxrs array
 
 256		 */
 257		offset = addr - offsetof(struct user, regs.fp_regs.fprs);
 258		tmp = *(addr_t *)((addr_t)child->thread.ufpu.vxrs + 2 * offset);
 259	} else if (addr < offsetof(struct user, regs.per_info) + sizeof(per_struct)) {
 
 
 
 
 
 
 260		/*
 261		 * Handle access to the per_info structure.
 262		 */
 263		addr -= offsetof(struct user, regs.per_info);
 264		tmp = __peek_user_per(child, addr);
 265
 266	} else
 267		tmp = 0;
 268
 269	return tmp;
 270}
 271
 272static int
 273peek_user(struct task_struct *child, addr_t addr, addr_t data)
 274{
 275	addr_t tmp, mask;
 276
 277	/*
 278	 * Stupid gdb peeks/pokes the access registers in 64 bit with
 279	 * an alignment of 4. Programmers from hell...
 280	 */
 281	mask = __ADDR_MASK;
 282	if (addr >= offsetof(struct user, regs.acrs) &&
 283	    addr < offsetof(struct user, regs.orig_gpr2))
 284		mask = 3;
 285	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 286		return -EIO;
 287
 288	tmp = __peek_user(child, addr);
 289	return put_user(tmp, (addr_t __user *) data);
 290}
 291
 292static inline void __poke_user_per(struct task_struct *child,
 293				   addr_t addr, addr_t data)
 294{
 
 
 295	/*
 296	 * There are only three fields in the per_info struct that the
 297	 * debugger user can write to.
 298	 * 1) cr9: the debugger wants to set a new PER event mask
 299	 * 2) starting_addr: the debugger wants to set a new starting
 300	 *    address to use with the PER event mask.
 301	 * 3) ending_addr: the debugger wants to set a new ending
 302	 *    address to use with the PER event mask.
 303	 * The user specified PER event mask and the start and end
 304	 * addresses are used only if single stepping is not in effect.
 305	 * Writes to any other field in per_info are ignored.
 306	 */
 307	if (addr == offsetof(struct per_struct_kernel, cr9))
 308		/* PER event mask of the user specified per set. */
 309		child->thread.per_user.control =
 310			data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 311	else if (addr == offsetof(struct per_struct_kernel, starting_addr))
 312		/* Starting address of the user specified per set. */
 313		child->thread.per_user.start = data;
 314	else if (addr == offsetof(struct per_struct_kernel, ending_addr))
 315		/* Ending address of the user specified per set. */
 316		child->thread.per_user.end = data;
 317}
 318
 319/*
 320 * Write a word to the user area of a process at location addr. This
 321 * operation does have an additional problem compared to peek_user.
 322 * Stores to the program status word and on the floating point
 323 * control register needs to get checked for validity.
 324 */
 325static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 326{
 
 327	addr_t offset;
 328
 329
 330	if (addr < offsetof(struct user, regs.acrs)) {
 331		struct pt_regs *regs = task_pt_regs(child);
 332		/*
 333		 * psw and gprs are stored on the stack
 334		 */
 335		if (addr == offsetof(struct user, regs.psw.mask)) {
 336			unsigned long mask = PSW_MASK_USER;
 337
 338			mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
 339			if ((data ^ PSW_USER_BITS) & ~mask)
 340				/* Invalid psw mask. */
 341				return -EINVAL;
 342			if ((data & PSW_MASK_ASC) == PSW_ASC_HOME)
 343				/* Invalid address-space-control bits */
 344				return -EINVAL;
 345			if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
 346				/* Invalid addressing mode bits */
 347				return -EINVAL;
 348		}
 349
 350		if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
 351			addr == offsetof(struct user, regs.gprs[2])) {
 352			struct pt_regs *regs = task_pt_regs(child);
 353
 354			regs->int_code = 0x20000 | (data & 0xffff);
 355		}
 356		*(addr_t *)((addr_t) &regs->psw + addr) = data;
 357	} else if (addr < offsetof(struct user, regs.orig_gpr2)) {
 358		/*
 359		 * access registers are stored in the thread structure
 360		 */
 361		offset = addr - offsetof(struct user, regs.acrs);
 362		/*
 363		 * Very special case: old & broken 64 bit gdb writing
 364		 * to acrs[15] with a 64 bit value. Ignore the lower
 365		 * half of the value and write the upper 32 bit to
 366		 * acrs[15]. Sick...
 367		 */
 368		if (addr == offsetof(struct user, regs.acrs[15]))
 369			child->thread.acrs[15] = (unsigned int) (data >> 32);
 370		else
 371			*(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 372
 373	} else if (addr == offsetof(struct user, regs.orig_gpr2)) {
 374		/*
 375		 * orig_gpr2 is stored on the kernel stack
 376		 */
 377		task_pt_regs(child)->orig_gpr2 = data;
 378
 379	} else if (addr < offsetof(struct user, regs.fp_regs)) {
 380		/*
 381		 * prevent writes of padding hole between
 382		 * orig_gpr2 and fp_regs on s390.
 383		 */
 384		return 0;
 385
 386	} else if (addr == offsetof(struct user, regs.fp_regs.fpc)) {
 387		/*
 388		 * floating point control reg. is in the thread structure
 389		 */
 390		if ((unsigned int)data != 0)
 
 391			return -EINVAL;
 392		child->thread.ufpu.fpc = data >> (BITS_PER_LONG - 32);
 393
 394	} else if (addr < offsetof(struct user, regs.fp_regs) + sizeof(s390_fp_regs)) {
 395		/*
 396		 * floating point regs. are in the child->thread.ufpu.vxrs array
 
 397		 */
 398		offset = addr - offsetof(struct user, regs.fp_regs.fprs);
 399		*(addr_t *)((addr_t)child->thread.ufpu.vxrs + 2 * offset) = data;
 400	} else if (addr < offsetof(struct user, regs.per_info) + sizeof(per_struct)) {
 
 
 
 
 
 
 401		/*
 402		 * Handle access to the per_info structure.
 403		 */
 404		addr -= offsetof(struct user, regs.per_info);
 405		__poke_user_per(child, addr, data);
 406
 407	}
 408
 409	return 0;
 410}
 411
 412static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
 413{
 414	addr_t mask;
 415
 416	/*
 417	 * Stupid gdb peeks/pokes the access registers in 64 bit with
 418	 * an alignment of 4. Programmers from hell indeed...
 419	 */
 420	mask = __ADDR_MASK;
 421	if (addr >= offsetof(struct user, regs.acrs) &&
 422	    addr < offsetof(struct user, regs.orig_gpr2))
 423		mask = 3;
 424	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 425		return -EIO;
 426
 427	return __poke_user(child, addr, data);
 428}
 429
 430long arch_ptrace(struct task_struct *child, long request,
 431		 unsigned long addr, unsigned long data)
 432{
 433	ptrace_area parea; 
 434	int copied, ret;
 435
 436	switch (request) {
 437	case PTRACE_PEEKUSR:
 438		/* read the word at location addr in the USER area. */
 439		return peek_user(child, addr, data);
 440
 441	case PTRACE_POKEUSR:
 442		/* write the word at location addr in the USER area */
 443		return poke_user(child, addr, data);
 444
 445	case PTRACE_PEEKUSR_AREA:
 446	case PTRACE_POKEUSR_AREA:
 447		if (copy_from_user(&parea, (void __force __user *) addr,
 448							sizeof(parea)))
 449			return -EFAULT;
 450		addr = parea.kernel_addr;
 451		data = parea.process_addr;
 452		copied = 0;
 453		while (copied < parea.len) {
 454			if (request == PTRACE_PEEKUSR_AREA)
 455				ret = peek_user(child, addr, data);
 456			else {
 457				addr_t utmp;
 458				if (get_user(utmp,
 459					     (addr_t __force __user *) data))
 460					return -EFAULT;
 461				ret = poke_user(child, addr, utmp);
 462			}
 463			if (ret)
 464				return ret;
 465			addr += sizeof(unsigned long);
 466			data += sizeof(unsigned long);
 467			copied += sizeof(unsigned long);
 468		}
 469		return 0;
 470	case PTRACE_GET_LAST_BREAK:
 471		return put_user(child->thread.last_break, (unsigned long __user *)data);
 
 
 472	case PTRACE_ENABLE_TE:
 473		if (!MACHINE_HAS_TE)
 474			return -EIO;
 475		child->thread.per_flags &= ~PER_FLAG_NO_TE;
 476		return 0;
 477	case PTRACE_DISABLE_TE:
 478		if (!MACHINE_HAS_TE)
 479			return -EIO;
 480		child->thread.per_flags |= PER_FLAG_NO_TE;
 481		child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 482		return 0;
 483	case PTRACE_TE_ABORT_RAND:
 484		if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
 485			return -EIO;
 486		switch (data) {
 487		case 0UL:
 488			child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 489			break;
 490		case 1UL:
 491			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 492			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
 493			break;
 494		case 2UL:
 495			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 496			child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
 497			break;
 498		default:
 499			return -EINVAL;
 500		}
 501		return 0;
 502	default:
 503		return ptrace_request(child, request, addr, data);
 504	}
 505}
 506
 507#ifdef CONFIG_COMPAT
 508/*
 509 * Now the fun part starts... a 31 bit program running in the
 510 * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 511 * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 512 * to handle, the difference to the 64 bit versions of the requests
 513 * is that the access is done in multiples of 4 byte instead of
 514 * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 515 * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 516 * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 517 * is a 31 bit program too, the content of struct user can be
 518 * emulated. A 31 bit program peeking into the struct user of
 519 * a 64 bit program is a no-no.
 520 */
 521
 522/*
 523 * Same as peek_user_per but for a 31 bit program.
 524 */
 525static inline __u32 __peek_user_per_compat(struct task_struct *child,
 526					   addr_t addr)
 527{
 528	if (addr == offsetof(struct compat_per_struct_kernel, cr9))
 
 
 529		/* Control bits of the active per set. */
 530		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 531			PER_EVENT_IFETCH : child->thread.per_user.control;
 532	else if (addr == offsetof(struct compat_per_struct_kernel, cr10))
 533		/* Start address of the active per set. */
 534		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 535			0 : child->thread.per_user.start;
 536	else if (addr == offsetof(struct compat_per_struct_kernel, cr11))
 537		/* End address of the active per set. */
 538		return test_thread_flag(TIF_SINGLE_STEP) ?
 539			PSW32_ADDR_INSN : child->thread.per_user.end;
 540	else if (addr == offsetof(struct compat_per_struct_kernel, bits))
 541		/* Single-step bit. */
 542		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 543			0x80000000 : 0;
 544	else if (addr == offsetof(struct compat_per_struct_kernel, starting_addr))
 545		/* Start address of the user specified per set. */
 546		return (__u32) child->thread.per_user.start;
 547	else if (addr == offsetof(struct compat_per_struct_kernel, ending_addr))
 548		/* End address of the user specified per set. */
 549		return (__u32) child->thread.per_user.end;
 550	else if (addr == offsetof(struct compat_per_struct_kernel, perc_atmid))
 551		/* PER code, ATMID and AI of the last PER trap */
 552		return (__u32) child->thread.per_event.cause << 16;
 553	else if (addr == offsetof(struct compat_per_struct_kernel, address))
 554		/* Address of the last PER trap */
 555		return (__u32) child->thread.per_event.address;
 556	else if (addr == offsetof(struct compat_per_struct_kernel, access_id))
 557		/* Access id of the last PER trap */
 558		return (__u32) child->thread.per_event.paid << 24;
 559	return 0;
 560}
 561
 562/*
 563 * Same as peek_user but for a 31 bit program.
 564 */
 565static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 566{
 
 567	addr_t offset;
 568	__u32 tmp;
 569
 570	if (addr < offsetof(struct compat_user, regs.acrs)) {
 571		struct pt_regs *regs = task_pt_regs(child);
 572		/*
 573		 * psw and gprs are stored on the stack
 574		 */
 575		if (addr == offsetof(struct compat_user, regs.psw.mask)) {
 576			/* Fake a 31 bit psw mask. */
 577			tmp = (__u32)(regs->psw.mask >> 32);
 578			tmp &= PSW32_MASK_USER | PSW32_MASK_RI;
 579			tmp |= PSW32_USER_BITS;
 580		} else if (addr == offsetof(struct compat_user, regs.psw.addr)) {
 581			/* Fake a 31 bit psw address. */
 582			tmp = (__u32) regs->psw.addr |
 583				(__u32)(regs->psw.mask & PSW_MASK_BA);
 584		} else {
 585			/* gpr 0-15 */
 586			tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
 587		}
 588	} else if (addr < offsetof(struct compat_user, regs.orig_gpr2)) {
 589		/*
 590		 * access registers are stored in the thread structure
 591		 */
 592		offset = addr - offsetof(struct compat_user, regs.acrs);
 593		tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 594
 595	} else if (addr == offsetof(struct compat_user, regs.orig_gpr2)) {
 596		/*
 597		 * orig_gpr2 is stored on the kernel stack
 598		 */
 599		tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 600
 601	} else if (addr < offsetof(struct compat_user, regs.fp_regs)) {
 602		/*
 603		 * prevent reads of padding hole between
 604		 * orig_gpr2 and fp_regs on s390.
 605		 */
 606		tmp = 0;
 607
 608	} else if (addr == offsetof(struct compat_user, regs.fp_regs.fpc)) {
 609		/*
 610		 * floating point control reg. is in the thread structure
 611		 */
 612		tmp = child->thread.ufpu.fpc;
 613
 614	} else if (addr < offsetof(struct compat_user, regs.fp_regs) + sizeof(s390_fp_regs)) {
 615		/*
 616		 * floating point regs. are in the child->thread.ufpu.vxrs array
 
 617		 */
 618		offset = addr - offsetof(struct compat_user, regs.fp_regs.fprs);
 619		tmp = *(__u32 *)((addr_t)child->thread.ufpu.vxrs + 2 * offset);
 620	} else if (addr < offsetof(struct compat_user, regs.per_info) + sizeof(struct compat_per_struct_kernel)) {
 
 
 
 
 
 
 621		/*
 622		 * Handle access to the per_info structure.
 623		 */
 624		addr -= offsetof(struct compat_user, regs.per_info);
 625		tmp = __peek_user_per_compat(child, addr);
 626
 627	} else
 628		tmp = 0;
 629
 630	return tmp;
 631}
 632
 633static int peek_user_compat(struct task_struct *child,
 634			    addr_t addr, addr_t data)
 635{
 636	__u32 tmp;
 637
 638	if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
 639		return -EIO;
 640
 641	tmp = __peek_user_compat(child, addr);
 642	return put_user(tmp, (__u32 __user *) data);
 643}
 644
 645/*
 646 * Same as poke_user_per but for a 31 bit program.
 647 */
 648static inline void __poke_user_per_compat(struct task_struct *child,
 649					  addr_t addr, __u32 data)
 650{
 651	if (addr == offsetof(struct compat_per_struct_kernel, cr9))
 
 
 652		/* PER event mask of the user specified per set. */
 653		child->thread.per_user.control =
 654			data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 655	else if (addr == offsetof(struct compat_per_struct_kernel, starting_addr))
 656		/* Starting address of the user specified per set. */
 657		child->thread.per_user.start = data;
 658	else if (addr == offsetof(struct compat_per_struct_kernel, ending_addr))
 659		/* Ending address of the user specified per set. */
 660		child->thread.per_user.end = data;
 661}
 662
 663/*
 664 * Same as poke_user but for a 31 bit program.
 665 */
 666static int __poke_user_compat(struct task_struct *child,
 667			      addr_t addr, addr_t data)
 668{
 
 669	__u32 tmp = (__u32) data;
 670	addr_t offset;
 671
 672	if (addr < offsetof(struct compat_user, regs.acrs)) {
 673		struct pt_regs *regs = task_pt_regs(child);
 674		/*
 675		 * psw, gprs, acrs and orig_gpr2 are stored on the stack
 676		 */
 677		if (addr == offsetof(struct compat_user, regs.psw.mask)) {
 678			__u32 mask = PSW32_MASK_USER;
 679
 680			mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
 681			/* Build a 64 bit psw mask from 31 bit mask. */
 682			if ((tmp ^ PSW32_USER_BITS) & ~mask)
 683				/* Invalid psw mask. */
 684				return -EINVAL;
 685			if ((data & PSW32_MASK_ASC) == PSW32_ASC_HOME)
 686				/* Invalid address-space-control bits */
 687				return -EINVAL;
 688			regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
 689				(regs->psw.mask & PSW_MASK_BA) |
 690				(__u64)(tmp & mask) << 32;
 691		} else if (addr == offsetof(struct compat_user, regs.psw.addr)) {
 692			/* Build a 64 bit psw address from 31 bit address. */
 693			regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
 694			/* Transfer 31 bit amode bit to psw mask. */
 695			regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
 696				(__u64)(tmp & PSW32_ADDR_AMODE);
 697		} else {
 698			if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
 699				addr == offsetof(struct compat_user, regs.gprs[2])) {
 700				struct pt_regs *regs = task_pt_regs(child);
 701
 702				regs->int_code = 0x20000 | (data & 0xffff);
 703			}
 704			/* gpr 0-15 */
 705			*(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
 706		}
 707	} else if (addr < offsetof(struct compat_user, regs.orig_gpr2)) {
 708		/*
 709		 * access registers are stored in the thread structure
 710		 */
 711		offset = addr - offsetof(struct compat_user, regs.acrs);
 712		*(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 713
 714	} else if (addr == offsetof(struct compat_user, regs.orig_gpr2)) {
 715		/*
 716		 * orig_gpr2 is stored on the kernel stack
 717		 */
 718		*(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 719
 720	} else if (addr < offsetof(struct compat_user, regs.fp_regs)) {
 721		/*
 722		 * prevent writess of padding hole between
 723		 * orig_gpr2 and fp_regs on s390.
 724		 */
 725		return 0;
 726
 727	} else if (addr == offsetof(struct compat_user, regs.fp_regs.fpc)) {
 728		/*
 729		 * floating point control reg. is in the thread structure
 730		 */
 731		child->thread.ufpu.fpc = data;
 
 
 732
 733	} else if (addr < offsetof(struct compat_user, regs.fp_regs) + sizeof(s390_fp_regs)) {
 734		/*
 735		 * floating point regs. are in the child->thread.ufpu.vxrs array
 
 736		 */
 737		offset = addr - offsetof(struct compat_user, regs.fp_regs.fprs);
 738		*(__u32 *)((addr_t)child->thread.ufpu.vxrs + 2 * offset) = tmp;
 739	} else if (addr < offsetof(struct compat_user, regs.per_info) + sizeof(struct compat_per_struct_kernel)) {
 
 
 
 
 
 
 740		/*
 741		 * Handle access to the per_info structure.
 742		 */
 743		addr -= offsetof(struct compat_user, regs.per_info);
 744		__poke_user_per_compat(child, addr, data);
 745	}
 746
 747	return 0;
 748}
 749
 750static int poke_user_compat(struct task_struct *child,
 751			    addr_t addr, addr_t data)
 752{
 753	if (!is_compat_task() || (addr & 3) ||
 754	    addr > sizeof(struct compat_user) - 3)
 755		return -EIO;
 756
 757	return __poke_user_compat(child, addr, data);
 758}
 759
 760long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 761			compat_ulong_t caddr, compat_ulong_t cdata)
 762{
 763	unsigned long addr = caddr;
 764	unsigned long data = cdata;
 765	compat_ptrace_area parea;
 766	int copied, ret;
 767
 768	switch (request) {
 769	case PTRACE_PEEKUSR:
 770		/* read the word at location addr in the USER area. */
 771		return peek_user_compat(child, addr, data);
 772
 773	case PTRACE_POKEUSR:
 774		/* write the word at location addr in the USER area */
 775		return poke_user_compat(child, addr, data);
 776
 777	case PTRACE_PEEKUSR_AREA:
 778	case PTRACE_POKEUSR_AREA:
 779		if (copy_from_user(&parea, (void __force __user *) addr,
 780							sizeof(parea)))
 781			return -EFAULT;
 782		addr = parea.kernel_addr;
 783		data = parea.process_addr;
 784		copied = 0;
 785		while (copied < parea.len) {
 786			if (request == PTRACE_PEEKUSR_AREA)
 787				ret = peek_user_compat(child, addr, data);
 788			else {
 789				__u32 utmp;
 790				if (get_user(utmp,
 791					     (__u32 __force __user *) data))
 792					return -EFAULT;
 793				ret = poke_user_compat(child, addr, utmp);
 794			}
 795			if (ret)
 796				return ret;
 797			addr += sizeof(unsigned int);
 798			data += sizeof(unsigned int);
 799			copied += sizeof(unsigned int);
 800		}
 801		return 0;
 802	case PTRACE_GET_LAST_BREAK:
 803		return put_user(child->thread.last_break, (unsigned int __user *)data);
 
 
 804	}
 805	return compat_ptrace_request(child, request, addr, data);
 806}
 807#endif
 808
 809/*
 810 * user_regset definitions.
 811 */
 812
 813static int s390_regs_get(struct task_struct *target,
 814			 const struct user_regset *regset,
 815			 struct membuf to)
 816{
 817	unsigned pos;
 818	if (target == current)
 819		save_access_regs(target->thread.acrs);
 820
 821	for (pos = 0; pos < sizeof(s390_regs); pos += sizeof(long))
 822		membuf_store(&to, __peek_user(target, pos));
 823	return 0;
 824}
 825
 826static int s390_regs_set(struct task_struct *target,
 827			 const struct user_regset *regset,
 828			 unsigned int pos, unsigned int count,
 829			 const void *kbuf, const void __user *ubuf)
 830{
 831	int rc = 0;
 832
 833	if (target == current)
 834		save_access_regs(target->thread.acrs);
 835
 836	if (kbuf) {
 837		const unsigned long *k = kbuf;
 838		while (count > 0 && !rc) {
 839			rc = __poke_user(target, pos, *k++);
 840			count -= sizeof(*k);
 841			pos += sizeof(*k);
 842		}
 843	} else {
 844		const unsigned long  __user *u = ubuf;
 845		while (count > 0 && !rc) {
 846			unsigned long word;
 847			rc = __get_user(word, u++);
 848			if (rc)
 849				break;
 850			rc = __poke_user(target, pos, word);
 851			count -= sizeof(*u);
 852			pos += sizeof(*u);
 853		}
 854	}
 855
 856	if (rc == 0 && target == current)
 857		restore_access_regs(target->thread.acrs);
 858
 859	return rc;
 860}
 861
 862static int s390_fpregs_get(struct task_struct *target,
 863			   const struct user_regset *regset,
 864			   struct membuf to)
 865{
 866	_s390_fp_regs fp_regs;
 867
 868	if (target == current)
 869		save_user_fpu_regs();
 870
 871	fp_regs.fpc = target->thread.ufpu.fpc;
 872	fpregs_store(&fp_regs, &target->thread.ufpu);
 873
 874	return membuf_write(&to, &fp_regs, sizeof(fp_regs));
 875}
 876
 877static int s390_fpregs_set(struct task_struct *target,
 878			   const struct user_regset *regset, unsigned int pos,
 879			   unsigned int count, const void *kbuf,
 880			   const void __user *ubuf)
 881{
 882	int rc = 0;
 883	freg_t fprs[__NUM_FPRS];
 884
 885	if (target == current)
 886		save_user_fpu_regs();
 887	convert_vx_to_fp(fprs, target->thread.ufpu.vxrs);
 
 
 
 
 
 
 888	if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 889		u32 ufpc[2] = { target->thread.ufpu.fpc, 0 };
 890		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
 891					0, offsetof(s390_fp_regs, fprs));
 892		if (rc)
 893			return rc;
 894		if (ufpc[1] != 0)
 895			return -EINVAL;
 896		target->thread.ufpu.fpc = ufpc[0];
 897	}
 898
 899	if (rc == 0 && count > 0)
 900		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 901					fprs, offsetof(s390_fp_regs, fprs), -1);
 902	if (rc)
 903		return rc;
 904	convert_fp_to_vx(target->thread.ufpu.vxrs, fprs);
 
 
 
 
 
 905	return rc;
 906}
 907
 908static int s390_last_break_get(struct task_struct *target,
 909			       const struct user_regset *regset,
 910			       struct membuf to)
 911{
 912	return membuf_store(&to, target->thread.last_break);
 913}
 914
 915static int s390_last_break_set(struct task_struct *target,
 916			       const struct user_regset *regset,
 917			       unsigned int pos, unsigned int count,
 918			       const void *kbuf, const void __user *ubuf)
 919{
 920	return 0;
 921}
 922
 923static int s390_tdb_get(struct task_struct *target,
 924			const struct user_regset *regset,
 925			struct membuf to)
 926{
 927	struct pt_regs *regs = task_pt_regs(target);
 928	size_t size;
 929
 930	if (!(regs->int_code & 0x200))
 931		return -ENODATA;
 932	size = sizeof(target->thread.trap_tdb.data);
 933	return membuf_write(&to, target->thread.trap_tdb.data, size);
 934}
 935
 936static int s390_tdb_set(struct task_struct *target,
 937			const struct user_regset *regset,
 938			unsigned int pos, unsigned int count,
 939			const void *kbuf, const void __user *ubuf)
 940{
 941	return 0;
 942}
 943
 944static int s390_vxrs_low_get(struct task_struct *target,
 945			     const struct user_regset *regset,
 946			     struct membuf to)
 947{
 948	__u64 vxrs[__NUM_VXRS_LOW];
 949	int i;
 950
 951	if (!cpu_has_vx())
 952		return -ENODEV;
 953	if (target == current)
 954		save_user_fpu_regs();
 955	for (i = 0; i < __NUM_VXRS_LOW; i++)
 956		vxrs[i] = target->thread.ufpu.vxrs[i].low;
 957	return membuf_write(&to, vxrs, sizeof(vxrs));
 958}
 959
 960static int s390_vxrs_low_set(struct task_struct *target,
 961			     const struct user_regset *regset,
 962			     unsigned int pos, unsigned int count,
 963			     const void *kbuf, const void __user *ubuf)
 964{
 965	__u64 vxrs[__NUM_VXRS_LOW];
 966	int i, rc;
 967
 968	if (!cpu_has_vx())
 969		return -ENODEV;
 970	if (target == current)
 971		save_user_fpu_regs();
 972
 973	for (i = 0; i < __NUM_VXRS_LOW; i++)
 974		vxrs[i] = target->thread.ufpu.vxrs[i].low;
 975
 976	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
 977	if (rc == 0)
 978		for (i = 0; i < __NUM_VXRS_LOW; i++)
 979			target->thread.ufpu.vxrs[i].low = vxrs[i];
 980
 981	return rc;
 982}
 983
 984static int s390_vxrs_high_get(struct task_struct *target,
 985			      const struct user_regset *regset,
 986			      struct membuf to)
 987{
 988	if (!cpu_has_vx())
 989		return -ENODEV;
 990	if (target == current)
 991		save_user_fpu_regs();
 992	return membuf_write(&to, target->thread.ufpu.vxrs + __NUM_VXRS_LOW,
 993			    __NUM_VXRS_HIGH * sizeof(__vector128));
 994}
 995
 996static int s390_vxrs_high_set(struct task_struct *target,
 997			      const struct user_regset *regset,
 998			      unsigned int pos, unsigned int count,
 999			      const void *kbuf, const void __user *ubuf)
1000{
1001	int rc;
1002
1003	if (!cpu_has_vx())
1004		return -ENODEV;
1005	if (target == current)
1006		save_user_fpu_regs();
1007
1008	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1009				target->thread.ufpu.vxrs + __NUM_VXRS_LOW, 0, -1);
1010	return rc;
1011}
1012
1013static int s390_system_call_get(struct task_struct *target,
1014				const struct user_regset *regset,
1015				struct membuf to)
1016{
1017	return membuf_store(&to, target->thread.system_call);
1018}
1019
1020static int s390_system_call_set(struct task_struct *target,
1021				const struct user_regset *regset,
1022				unsigned int pos, unsigned int count,
1023				const void *kbuf, const void __user *ubuf)
1024{
1025	unsigned int *data = &target->thread.system_call;
1026	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1027				  data, 0, sizeof(unsigned int));
1028}
1029
1030static int s390_gs_cb_get(struct task_struct *target,
1031			  const struct user_regset *regset,
1032			  struct membuf to)
1033{
1034	struct gs_cb *data = target->thread.gs_cb;
1035
1036	if (!MACHINE_HAS_GS)
1037		return -ENODEV;
1038	if (!data)
1039		return -ENODATA;
1040	if (target == current)
1041		save_gs_cb(data);
1042	return membuf_write(&to, data, sizeof(struct gs_cb));
1043}
1044
1045static int s390_gs_cb_set(struct task_struct *target,
1046			  const struct user_regset *regset,
1047			  unsigned int pos, unsigned int count,
1048			  const void *kbuf, const void __user *ubuf)
1049{
1050	struct gs_cb gs_cb = { }, *data = NULL;
1051	int rc;
1052
1053	if (!MACHINE_HAS_GS)
1054		return -ENODEV;
1055	if (!target->thread.gs_cb) {
1056		data = kzalloc(sizeof(*data), GFP_KERNEL);
1057		if (!data)
1058			return -ENOMEM;
1059	}
1060	if (!target->thread.gs_cb)
1061		gs_cb.gsd = 25;
1062	else if (target == current)
1063		save_gs_cb(&gs_cb);
1064	else
1065		gs_cb = *target->thread.gs_cb;
1066	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1067				&gs_cb, 0, sizeof(gs_cb));
1068	if (rc) {
1069		kfree(data);
1070		return -EFAULT;
1071	}
1072	preempt_disable();
1073	if (!target->thread.gs_cb)
1074		target->thread.gs_cb = data;
1075	*target->thread.gs_cb = gs_cb;
1076	if (target == current) {
1077		local_ctl_set_bit(2, CR2_GUARDED_STORAGE_BIT);
1078		restore_gs_cb(target->thread.gs_cb);
1079	}
1080	preempt_enable();
1081	return rc;
1082}
1083
1084static int s390_gs_bc_get(struct task_struct *target,
1085			  const struct user_regset *regset,
1086			  struct membuf to)
1087{
1088	struct gs_cb *data = target->thread.gs_bc_cb;
1089
1090	if (!MACHINE_HAS_GS)
1091		return -ENODEV;
1092	if (!data)
1093		return -ENODATA;
1094	return membuf_write(&to, data, sizeof(struct gs_cb));
1095}
1096
1097static int s390_gs_bc_set(struct task_struct *target,
1098			  const struct user_regset *regset,
1099			  unsigned int pos, unsigned int count,
1100			  const void *kbuf, const void __user *ubuf)
1101{
1102	struct gs_cb *data = target->thread.gs_bc_cb;
1103
1104	if (!MACHINE_HAS_GS)
1105		return -ENODEV;
1106	if (!data) {
1107		data = kzalloc(sizeof(*data), GFP_KERNEL);
1108		if (!data)
1109			return -ENOMEM;
1110		target->thread.gs_bc_cb = data;
1111	}
1112	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1113				  data, 0, sizeof(struct gs_cb));
1114}
1115
1116static bool is_ri_cb_valid(struct runtime_instr_cb *cb)
1117{
1118	return (cb->rca & 0x1f) == 0 &&
1119		(cb->roa & 0xfff) == 0 &&
1120		(cb->rla & 0xfff) == 0xfff &&
1121		cb->s == 1 &&
1122		cb->k == 1 &&
1123		cb->h == 0 &&
1124		cb->reserved1 == 0 &&
1125		cb->ps == 1 &&
1126		cb->qs == 0 &&
1127		cb->pc == 1 &&
1128		cb->qc == 0 &&
1129		cb->reserved2 == 0 &&
1130		cb->reserved3 == 0 &&
1131		cb->reserved4 == 0 &&
1132		cb->reserved5 == 0 &&
1133		cb->reserved6 == 0 &&
1134		cb->reserved7 == 0 &&
1135		cb->reserved8 == 0 &&
1136		cb->rla >= cb->roa &&
1137		cb->rca >= cb->roa &&
1138		cb->rca <= cb->rla+1 &&
1139		cb->m < 3;
1140}
1141
1142static int s390_runtime_instr_get(struct task_struct *target,
1143				const struct user_regset *regset,
1144				struct membuf to)
1145{
1146	struct runtime_instr_cb *data = target->thread.ri_cb;
1147
1148	if (!test_facility(64))
1149		return -ENODEV;
1150	if (!data)
1151		return -ENODATA;
1152
1153	return membuf_write(&to, data, sizeof(struct runtime_instr_cb));
1154}
1155
1156static int s390_runtime_instr_set(struct task_struct *target,
1157				  const struct user_regset *regset,
1158				  unsigned int pos, unsigned int count,
1159				  const void *kbuf, const void __user *ubuf)
1160{
1161	struct runtime_instr_cb ri_cb = { }, *data = NULL;
1162	int rc;
1163
1164	if (!test_facility(64))
1165		return -ENODEV;
1166
1167	if (!target->thread.ri_cb) {
1168		data = kzalloc(sizeof(*data), GFP_KERNEL);
1169		if (!data)
1170			return -ENOMEM;
1171	}
1172
1173	if (target->thread.ri_cb) {
1174		if (target == current)
1175			store_runtime_instr_cb(&ri_cb);
1176		else
1177			ri_cb = *target->thread.ri_cb;
1178	}
1179
1180	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1181				&ri_cb, 0, sizeof(struct runtime_instr_cb));
1182	if (rc) {
1183		kfree(data);
1184		return -EFAULT;
1185	}
1186
1187	if (!is_ri_cb_valid(&ri_cb)) {
1188		kfree(data);
1189		return -EINVAL;
1190	}
1191	/*
1192	 * Override access key in any case, since user space should
1193	 * not be able to set it, nor should it care about it.
1194	 */
1195	ri_cb.key = PAGE_DEFAULT_KEY >> 4;
1196	preempt_disable();
1197	if (!target->thread.ri_cb)
1198		target->thread.ri_cb = data;
1199	*target->thread.ri_cb = ri_cb;
1200	if (target == current)
1201		load_runtime_instr_cb(target->thread.ri_cb);
1202	preempt_enable();
1203
1204	return 0;
1205}
1206
1207static const struct user_regset s390_regsets[] = {
1208	{
1209		.core_note_type = NT_PRSTATUS,
1210		.n = sizeof(s390_regs) / sizeof(long),
1211		.size = sizeof(long),
1212		.align = sizeof(long),
1213		.regset_get = s390_regs_get,
1214		.set = s390_regs_set,
1215	},
1216	{
1217		.core_note_type = NT_PRFPREG,
1218		.n = sizeof(s390_fp_regs) / sizeof(long),
1219		.size = sizeof(long),
1220		.align = sizeof(long),
1221		.regset_get = s390_fpregs_get,
1222		.set = s390_fpregs_set,
1223	},
1224	{
1225		.core_note_type = NT_S390_SYSTEM_CALL,
1226		.n = 1,
1227		.size = sizeof(unsigned int),
1228		.align = sizeof(unsigned int),
1229		.regset_get = s390_system_call_get,
1230		.set = s390_system_call_set,
1231	},
1232	{
1233		.core_note_type = NT_S390_LAST_BREAK,
1234		.n = 1,
1235		.size = sizeof(long),
1236		.align = sizeof(long),
1237		.regset_get = s390_last_break_get,
1238		.set = s390_last_break_set,
1239	},
1240	{
1241		.core_note_type = NT_S390_TDB,
1242		.n = 1,
1243		.size = 256,
1244		.align = 1,
1245		.regset_get = s390_tdb_get,
1246		.set = s390_tdb_set,
1247	},
1248	{
1249		.core_note_type = NT_S390_VXRS_LOW,
1250		.n = __NUM_VXRS_LOW,
1251		.size = sizeof(__u64),
1252		.align = sizeof(__u64),
1253		.regset_get = s390_vxrs_low_get,
1254		.set = s390_vxrs_low_set,
1255	},
1256	{
1257		.core_note_type = NT_S390_VXRS_HIGH,
1258		.n = __NUM_VXRS_HIGH,
1259		.size = sizeof(__vector128),
1260		.align = sizeof(__vector128),
1261		.regset_get = s390_vxrs_high_get,
1262		.set = s390_vxrs_high_set,
1263	},
1264	{
1265		.core_note_type = NT_S390_GS_CB,
1266		.n = sizeof(struct gs_cb) / sizeof(__u64),
1267		.size = sizeof(__u64),
1268		.align = sizeof(__u64),
1269		.regset_get = s390_gs_cb_get,
1270		.set = s390_gs_cb_set,
1271	},
1272	{
1273		.core_note_type = NT_S390_GS_BC,
1274		.n = sizeof(struct gs_cb) / sizeof(__u64),
1275		.size = sizeof(__u64),
1276		.align = sizeof(__u64),
1277		.regset_get = s390_gs_bc_get,
1278		.set = s390_gs_bc_set,
1279	},
1280	{
1281		.core_note_type = NT_S390_RI_CB,
1282		.n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1283		.size = sizeof(__u64),
1284		.align = sizeof(__u64),
1285		.regset_get = s390_runtime_instr_get,
1286		.set = s390_runtime_instr_set,
1287	},
1288};
1289
1290static const struct user_regset_view user_s390_view = {
1291	.name = "s390x",
1292	.e_machine = EM_S390,
1293	.regsets = s390_regsets,
1294	.n = ARRAY_SIZE(s390_regsets)
1295};
1296
1297#ifdef CONFIG_COMPAT
1298static int s390_compat_regs_get(struct task_struct *target,
1299				const struct user_regset *regset,
1300				struct membuf to)
1301{
1302	unsigned n;
1303
1304	if (target == current)
1305		save_access_regs(target->thread.acrs);
1306
1307	for (n = 0; n < sizeof(s390_compat_regs); n += sizeof(compat_ulong_t))
1308		membuf_store(&to, __peek_user_compat(target, n));
1309	return 0;
1310}
1311
1312static int s390_compat_regs_set(struct task_struct *target,
1313				const struct user_regset *regset,
1314				unsigned int pos, unsigned int count,
1315				const void *kbuf, const void __user *ubuf)
1316{
1317	int rc = 0;
1318
1319	if (target == current)
1320		save_access_regs(target->thread.acrs);
1321
1322	if (kbuf) {
1323		const compat_ulong_t *k = kbuf;
1324		while (count > 0 && !rc) {
1325			rc = __poke_user_compat(target, pos, *k++);
1326			count -= sizeof(*k);
1327			pos += sizeof(*k);
1328		}
1329	} else {
1330		const compat_ulong_t  __user *u = ubuf;
1331		while (count > 0 && !rc) {
1332			compat_ulong_t word;
1333			rc = __get_user(word, u++);
1334			if (rc)
1335				break;
1336			rc = __poke_user_compat(target, pos, word);
1337			count -= sizeof(*u);
1338			pos += sizeof(*u);
1339		}
1340	}
1341
1342	if (rc == 0 && target == current)
1343		restore_access_regs(target->thread.acrs);
1344
1345	return rc;
1346}
1347
1348static int s390_compat_regs_high_get(struct task_struct *target,
1349				     const struct user_regset *regset,
1350				     struct membuf to)
1351{
1352	compat_ulong_t *gprs_high;
1353	int i;
1354
1355	gprs_high = (compat_ulong_t *)task_pt_regs(target)->gprs;
1356	for (i = 0; i < NUM_GPRS; i++, gprs_high += 2)
1357		membuf_store(&to, *gprs_high);
1358	return 0;
1359}
1360
1361static int s390_compat_regs_high_set(struct task_struct *target,
1362				     const struct user_regset *regset,
1363				     unsigned int pos, unsigned int count,
1364				     const void *kbuf, const void __user *ubuf)
1365{
1366	compat_ulong_t *gprs_high;
1367	int rc = 0;
1368
1369	gprs_high = (compat_ulong_t *)
1370		&task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1371	if (kbuf) {
1372		const compat_ulong_t *k = kbuf;
1373		while (count > 0) {
1374			*gprs_high = *k++;
1375			*gprs_high += 2;
1376			count -= sizeof(*k);
1377		}
1378	} else {
1379		const compat_ulong_t  __user *u = ubuf;
1380		while (count > 0 && !rc) {
1381			unsigned long word;
1382			rc = __get_user(word, u++);
1383			if (rc)
1384				break;
1385			*gprs_high = word;
1386			*gprs_high += 2;
1387			count -= sizeof(*u);
1388		}
1389	}
1390
1391	return rc;
1392}
1393
1394static int s390_compat_last_break_get(struct task_struct *target,
1395				      const struct user_regset *regset,
1396				      struct membuf to)
1397{
1398	compat_ulong_t last_break = target->thread.last_break;
1399
1400	return membuf_store(&to, (unsigned long)last_break);
1401}
1402
1403static int s390_compat_last_break_set(struct task_struct *target,
1404				      const struct user_regset *regset,
1405				      unsigned int pos, unsigned int count,
1406				      const void *kbuf, const void __user *ubuf)
1407{
1408	return 0;
1409}
1410
1411static const struct user_regset s390_compat_regsets[] = {
1412	{
1413		.core_note_type = NT_PRSTATUS,
1414		.n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1415		.size = sizeof(compat_long_t),
1416		.align = sizeof(compat_long_t),
1417		.regset_get = s390_compat_regs_get,
1418		.set = s390_compat_regs_set,
1419	},
1420	{
1421		.core_note_type = NT_PRFPREG,
1422		.n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1423		.size = sizeof(compat_long_t),
1424		.align = sizeof(compat_long_t),
1425		.regset_get = s390_fpregs_get,
1426		.set = s390_fpregs_set,
1427	},
1428	{
1429		.core_note_type = NT_S390_SYSTEM_CALL,
1430		.n = 1,
1431		.size = sizeof(compat_uint_t),
1432		.align = sizeof(compat_uint_t),
1433		.regset_get = s390_system_call_get,
1434		.set = s390_system_call_set,
1435	},
1436	{
1437		.core_note_type = NT_S390_LAST_BREAK,
1438		.n = 1,
1439		.size = sizeof(long),
1440		.align = sizeof(long),
1441		.regset_get = s390_compat_last_break_get,
1442		.set = s390_compat_last_break_set,
1443	},
1444	{
1445		.core_note_type = NT_S390_TDB,
1446		.n = 1,
1447		.size = 256,
1448		.align = 1,
1449		.regset_get = s390_tdb_get,
1450		.set = s390_tdb_set,
1451	},
1452	{
1453		.core_note_type = NT_S390_VXRS_LOW,
1454		.n = __NUM_VXRS_LOW,
1455		.size = sizeof(__u64),
1456		.align = sizeof(__u64),
1457		.regset_get = s390_vxrs_low_get,
1458		.set = s390_vxrs_low_set,
1459	},
1460	{
1461		.core_note_type = NT_S390_VXRS_HIGH,
1462		.n = __NUM_VXRS_HIGH,
1463		.size = sizeof(__vector128),
1464		.align = sizeof(__vector128),
1465		.regset_get = s390_vxrs_high_get,
1466		.set = s390_vxrs_high_set,
1467	},
1468	{
1469		.core_note_type = NT_S390_HIGH_GPRS,
1470		.n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1471		.size = sizeof(compat_long_t),
1472		.align = sizeof(compat_long_t),
1473		.regset_get = s390_compat_regs_high_get,
1474		.set = s390_compat_regs_high_set,
1475	},
1476	{
1477		.core_note_type = NT_S390_GS_CB,
1478		.n = sizeof(struct gs_cb) / sizeof(__u64),
1479		.size = sizeof(__u64),
1480		.align = sizeof(__u64),
1481		.regset_get = s390_gs_cb_get,
1482		.set = s390_gs_cb_set,
1483	},
1484	{
1485		.core_note_type = NT_S390_GS_BC,
1486		.n = sizeof(struct gs_cb) / sizeof(__u64),
1487		.size = sizeof(__u64),
1488		.align = sizeof(__u64),
1489		.regset_get = s390_gs_bc_get,
1490		.set = s390_gs_bc_set,
1491	},
1492	{
1493		.core_note_type = NT_S390_RI_CB,
1494		.n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1495		.size = sizeof(__u64),
1496		.align = sizeof(__u64),
1497		.regset_get = s390_runtime_instr_get,
1498		.set = s390_runtime_instr_set,
1499	},
1500};
1501
1502static const struct user_regset_view user_s390_compat_view = {
1503	.name = "s390",
1504	.e_machine = EM_S390,
1505	.regsets = s390_compat_regsets,
1506	.n = ARRAY_SIZE(s390_compat_regsets)
1507};
1508#endif
1509
1510const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1511{
1512#ifdef CONFIG_COMPAT
1513	if (test_tsk_thread_flag(task, TIF_31BIT))
1514		return &user_s390_compat_view;
1515#endif
1516	return &user_s390_view;
1517}
1518
1519static const char *gpr_names[NUM_GPRS] = {
1520	"r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1521	"r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1522};
1523
1524unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1525{
1526	if (offset >= NUM_GPRS)
1527		return 0;
1528	return regs->gprs[offset];
1529}
1530
1531int regs_query_register_offset(const char *name)
1532{
1533	unsigned long offset;
1534
1535	if (!name || *name != 'r')
1536		return -EINVAL;
1537	if (kstrtoul(name + 1, 10, &offset))
1538		return -EINVAL;
1539	if (offset >= NUM_GPRS)
1540		return -EINVAL;
1541	return offset;
1542}
1543
1544const char *regs_query_register_name(unsigned int offset)
1545{
1546	if (offset >= NUM_GPRS)
1547		return NULL;
1548	return gpr_names[offset];
1549}
1550
1551static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1552{
1553	unsigned long ksp = kernel_stack_pointer(regs);
1554
1555	return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1556}
1557
1558/**
1559 * regs_get_kernel_stack_nth() - get Nth entry of the stack
1560 * @regs:pt_regs which contains kernel stack pointer.
1561 * @n:stack entry number.
1562 *
1563 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1564 * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1565 * this returns 0.
1566 */
1567unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1568{
1569	unsigned long addr;
1570
1571	addr = kernel_stack_pointer(regs) + n * sizeof(long);
1572	if (!regs_within_kernel_stack(regs, addr))
1573		return 0;
1574	return *(unsigned long *)addr;
1575}
v5.14.15
   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/tracehook.h>
  25#include <linux/seccomp.h>
  26#include <linux/compat.h>
  27#include <trace/syscall.h>
 
 
  28#include <asm/page.h>
  29#include <linux/uaccess.h>
  30#include <asm/unistd.h>
  31#include <asm/switch_to.h>
  32#include <asm/runtime_instr.h>
  33#include <asm/facility.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	struct per_regs old, new;
  46	union ctlreg0 cr0_old, cr0_new;
  47	union ctlreg2 cr2_old, cr2_new;
  48	int cr0_changed, cr2_changed;
 
 
 
 
 
 
 
 
  49
  50	__ctl_store(cr0_old.val, 0, 0);
  51	__ctl_store(cr2_old.val, 2, 2);
  52	cr0_new = cr0_old;
  53	cr2_new = cr2_old;
  54	/* Take care of the enable/disable of transactional execution. */
  55	if (MACHINE_HAS_TE) {
  56		/* Set or clear transaction execution TXC bit 8. */
  57		cr0_new.tcx = 1;
  58		if (task->thread.per_flags & PER_FLAG_NO_TE)
  59			cr0_new.tcx = 0;
  60		/* Set or clear transaction execution TDC bits 62 and 63. */
  61		cr2_new.tdc = 0;
  62		if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
  63			if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND_TEND)
  64				cr2_new.tdc = 1;
  65			else
  66				cr2_new.tdc = 2;
  67		}
  68	}
  69	/* Take care of enable/disable of guarded storage. */
  70	if (MACHINE_HAS_GS) {
  71		cr2_new.gse = 0;
  72		if (task->thread.gs_cb)
  73			cr2_new.gse = 1;
  74	}
  75	/* Load control register 0/2 iff changed */
  76	cr0_changed = cr0_new.val != cr0_old.val;
  77	cr2_changed = cr2_new.val != cr2_old.val;
  78	if (cr0_changed)
  79		__ctl_load(cr0_new.val, 0, 0);
  80	if (cr2_changed)
  81		__ctl_load(cr2_new.val, 2, 2);
  82	/* Copy user specified PER registers */
  83	new.control = thread->per_user.control;
  84	new.start = thread->per_user.start;
  85	new.end = thread->per_user.end;
  86
  87	/* merge TIF_SINGLE_STEP into user specified PER registers. */
  88	if (test_tsk_thread_flag(task, TIF_SINGLE_STEP) ||
  89	    test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP)) {
  90		if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))
  91			new.control |= PER_EVENT_BRANCH;
  92		else
  93			new.control |= PER_EVENT_IFETCH;
  94		new.control |= PER_CONTROL_SUSPENSION;
  95		new.control |= PER_EVENT_TRANSACTION_END;
  96		if (test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP))
  97			new.control |= PER_EVENT_IFETCH;
  98		new.start = 0;
  99		new.end = -1UL;
 100	}
 101
 102	/* Take care of the PER enablement bit in the PSW. */
 103	if (!(new.control & PER_EVENT_MASK)) {
 104		regs->psw.mask &= ~PSW_MASK_PER;
 105		return;
 106	}
 107	regs->psw.mask |= PSW_MASK_PER;
 108	__ctl_store(old, 9, 11);
 109	if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
 110		__ctl_load(new, 9, 11);
 111}
 112
 113void user_enable_single_step(struct task_struct *task)
 114{
 115	clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
 116	set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 117}
 118
 119void user_disable_single_step(struct task_struct *task)
 120{
 121	clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
 122	clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 123}
 124
 125void user_enable_block_step(struct task_struct *task)
 126{
 127	set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 128	set_tsk_thread_flag(task, TIF_BLOCK_STEP);
 129}
 130
 131/*
 132 * Called by kernel/ptrace.c when detaching..
 133 *
 134 * Clear all debugging related fields.
 135 */
 136void ptrace_disable(struct task_struct *task)
 137{
 138	memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
 139	memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
 140	clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 141	clear_tsk_thread_flag(task, TIF_PER_TRAP);
 142	task->thread.per_flags = 0;
 143}
 144
 145#define __ADDR_MASK 7
 146
 147static inline unsigned long __peek_user_per(struct task_struct *child,
 148					    addr_t addr)
 149{
 150	struct per_struct_kernel *dummy = NULL;
 151
 152	if (addr == (addr_t) &dummy->cr9)
 153		/* Control bits of the active per set. */
 154		return test_thread_flag(TIF_SINGLE_STEP) ?
 155			PER_EVENT_IFETCH : child->thread.per_user.control;
 156	else if (addr == (addr_t) &dummy->cr10)
 157		/* Start address of the active per set. */
 158		return test_thread_flag(TIF_SINGLE_STEP) ?
 159			0 : child->thread.per_user.start;
 160	else if (addr == (addr_t) &dummy->cr11)
 161		/* End address of the active per set. */
 162		return test_thread_flag(TIF_SINGLE_STEP) ?
 163			-1UL : child->thread.per_user.end;
 164	else if (addr == (addr_t) &dummy->bits)
 165		/* Single-step bit. */
 166		return test_thread_flag(TIF_SINGLE_STEP) ?
 167			(1UL << (BITS_PER_LONG - 1)) : 0;
 168	else if (addr == (addr_t) &dummy->starting_addr)
 169		/* Start address of the user specified per set. */
 170		return child->thread.per_user.start;
 171	else if (addr == (addr_t) &dummy->ending_addr)
 172		/* End address of the user specified per set. */
 173		return child->thread.per_user.end;
 174	else if (addr == (addr_t) &dummy->perc_atmid)
 175		/* PER code, ATMID and AI of the last PER trap */
 176		return (unsigned long)
 177			child->thread.per_event.cause << (BITS_PER_LONG - 16);
 178	else if (addr == (addr_t) &dummy->address)
 179		/* Address of the last PER trap */
 180		return child->thread.per_event.address;
 181	else if (addr == (addr_t) &dummy->access_id)
 182		/* Access id of the last PER trap */
 183		return (unsigned long)
 184			child->thread.per_event.paid << (BITS_PER_LONG - 8);
 185	return 0;
 186}
 187
 188/*
 189 * Read the word at offset addr from the user area of a process. The
 190 * trouble here is that the information is littered over different
 191 * locations. The process registers are found on the kernel stack,
 192 * the floating point stuff and the trace settings are stored in
 193 * the task structure. In addition the different structures in
 194 * struct user contain pad bytes that should be read as zeroes.
 195 * Lovely...
 196 */
 197static unsigned long __peek_user(struct task_struct *child, addr_t addr)
 198{
 199	struct user *dummy = NULL;
 200	addr_t offset, tmp;
 201
 202	if (addr < (addr_t) &dummy->regs.acrs) {
 203		/*
 204		 * psw and gprs are stored on the stack
 205		 */
 206		tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
 207		if (addr == (addr_t) &dummy->regs.psw.mask) {
 208			/* Return a clean psw mask. */
 209			tmp &= PSW_MASK_USER | PSW_MASK_RI;
 210			tmp |= PSW_USER_BITS;
 211		}
 212
 213	} else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
 214		/*
 215		 * access registers are stored in the thread structure
 216		 */
 217		offset = addr - (addr_t) &dummy->regs.acrs;
 218		/*
 219		 * Very special case: old & broken 64 bit gdb reading
 220		 * from acrs[15]. Result is a 64 bit value. Read the
 221		 * 32 bit acrs[15] value and shift it by 32. Sick...
 222		 */
 223		if (addr == (addr_t) &dummy->regs.acrs[15])
 224			tmp = ((unsigned long) child->thread.acrs[15]) << 32;
 225		else
 226			tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
 227
 228	} else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 229		/*
 230		 * orig_gpr2 is stored on the kernel stack
 231		 */
 232		tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
 233
 234	} else if (addr < (addr_t) &dummy->regs.fp_regs) {
 235		/*
 236		 * prevent reads of padding hole between
 237		 * orig_gpr2 and fp_regs on s390.
 238		 */
 239		tmp = 0;
 240
 241	} else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
 242		/*
 243		 * floating point control reg. is in the thread structure
 244		 */
 245		tmp = child->thread.fpu.fpc;
 246		tmp <<= BITS_PER_LONG - 32;
 247
 248	} else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 249		/*
 250		 * floating point regs. are either in child->thread.fpu
 251		 * or the child->thread.fpu.vxrs array
 252		 */
 253		offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
 254		if (MACHINE_HAS_VX)
 255			tmp = *(addr_t *)
 256			       ((addr_t) child->thread.fpu.vxrs + 2*offset);
 257		else
 258			tmp = *(addr_t *)
 259			       ((addr_t) child->thread.fpu.fprs + offset);
 260
 261	} else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 262		/*
 263		 * Handle access to the per_info structure.
 264		 */
 265		addr -= (addr_t) &dummy->regs.per_info;
 266		tmp = __peek_user_per(child, addr);
 267
 268	} else
 269		tmp = 0;
 270
 271	return tmp;
 272}
 273
 274static int
 275peek_user(struct task_struct *child, addr_t addr, addr_t data)
 276{
 277	addr_t tmp, mask;
 278
 279	/*
 280	 * Stupid gdb peeks/pokes the access registers in 64 bit with
 281	 * an alignment of 4. Programmers from hell...
 282	 */
 283	mask = __ADDR_MASK;
 284	if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 285	    addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 286		mask = 3;
 287	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 288		return -EIO;
 289
 290	tmp = __peek_user(child, addr);
 291	return put_user(tmp, (addr_t __user *) data);
 292}
 293
 294static inline void __poke_user_per(struct task_struct *child,
 295				   addr_t addr, addr_t data)
 296{
 297	struct per_struct_kernel *dummy = NULL;
 298
 299	/*
 300	 * There are only three fields in the per_info struct that the
 301	 * debugger user can write to.
 302	 * 1) cr9: the debugger wants to set a new PER event mask
 303	 * 2) starting_addr: the debugger wants to set a new starting
 304	 *    address to use with the PER event mask.
 305	 * 3) ending_addr: the debugger wants to set a new ending
 306	 *    address to use with the PER event mask.
 307	 * The user specified PER event mask and the start and end
 308	 * addresses are used only if single stepping is not in effect.
 309	 * Writes to any other field in per_info are ignored.
 310	 */
 311	if (addr == (addr_t) &dummy->cr9)
 312		/* PER event mask of the user specified per set. */
 313		child->thread.per_user.control =
 314			data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 315	else if (addr == (addr_t) &dummy->starting_addr)
 316		/* Starting address of the user specified per set. */
 317		child->thread.per_user.start = data;
 318	else if (addr == (addr_t) &dummy->ending_addr)
 319		/* Ending address of the user specified per set. */
 320		child->thread.per_user.end = data;
 321}
 322
 323/*
 324 * Write a word to the user area of a process at location addr. This
 325 * operation does have an additional problem compared to peek_user.
 326 * Stores to the program status word and on the floating point
 327 * control register needs to get checked for validity.
 328 */
 329static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 330{
 331	struct user *dummy = NULL;
 332	addr_t offset;
 333
 334
 335	if (addr < (addr_t) &dummy->regs.acrs) {
 336		struct pt_regs *regs = task_pt_regs(child);
 337		/*
 338		 * psw and gprs are stored on the stack
 339		 */
 340		if (addr == (addr_t) &dummy->regs.psw.mask) {
 341			unsigned long mask = PSW_MASK_USER;
 342
 343			mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
 344			if ((data ^ PSW_USER_BITS) & ~mask)
 345				/* Invalid psw mask. */
 346				return -EINVAL;
 347			if ((data & PSW_MASK_ASC) == PSW_ASC_HOME)
 348				/* Invalid address-space-control bits */
 349				return -EINVAL;
 350			if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
 351				/* Invalid addressing mode bits */
 352				return -EINVAL;
 353		}
 354
 355		if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
 356			addr == offsetof(struct user, regs.gprs[2])) {
 357			struct pt_regs *regs = task_pt_regs(child);
 358
 359			regs->int_code = 0x20000 | (data & 0xffff);
 360		}
 361		*(addr_t *)((addr_t) &regs->psw + addr) = data;
 362	} else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
 363		/*
 364		 * access registers are stored in the thread structure
 365		 */
 366		offset = addr - (addr_t) &dummy->regs.acrs;
 367		/*
 368		 * Very special case: old & broken 64 bit gdb writing
 369		 * to acrs[15] with a 64 bit value. Ignore the lower
 370		 * half of the value and write the upper 32 bit to
 371		 * acrs[15]. Sick...
 372		 */
 373		if (addr == (addr_t) &dummy->regs.acrs[15])
 374			child->thread.acrs[15] = (unsigned int) (data >> 32);
 375		else
 376			*(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 377
 378	} else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 379		/*
 380		 * orig_gpr2 is stored on the kernel stack
 381		 */
 382		task_pt_regs(child)->orig_gpr2 = data;
 383
 384	} else if (addr < (addr_t) &dummy->regs.fp_regs) {
 385		/*
 386		 * prevent writes of padding hole between
 387		 * orig_gpr2 and fp_regs on s390.
 388		 */
 389		return 0;
 390
 391	} else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
 392		/*
 393		 * floating point control reg. is in the thread structure
 394		 */
 395		if ((unsigned int) data != 0 ||
 396		    test_fp_ctl(data >> (BITS_PER_LONG - 32)))
 397			return -EINVAL;
 398		child->thread.fpu.fpc = data >> (BITS_PER_LONG - 32);
 399
 400	} else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 401		/*
 402		 * floating point regs. are either in child->thread.fpu
 403		 * or the child->thread.fpu.vxrs array
 404		 */
 405		offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
 406		if (MACHINE_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 < (addr_t) (&dummy->regs.per_info + 1)) {
 414		/*
 415		 * Handle access to the per_info structure.
 416		 */
 417		addr -= (addr_t) &dummy->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 >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 435	    addr < (addr_t) &((struct user *) NULL)->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		put_user(child->thread.last_break,
 485			 (unsigned long __user *) data);
 486		return 0;
 487	case PTRACE_ENABLE_TE:
 488		if (!MACHINE_HAS_TE)
 489			return -EIO;
 490		child->thread.per_flags &= ~PER_FLAG_NO_TE;
 491		return 0;
 492	case PTRACE_DISABLE_TE:
 493		if (!MACHINE_HAS_TE)
 494			return -EIO;
 495		child->thread.per_flags |= PER_FLAG_NO_TE;
 496		child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 497		return 0;
 498	case PTRACE_TE_ABORT_RAND:
 499		if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
 500			return -EIO;
 501		switch (data) {
 502		case 0UL:
 503			child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 504			break;
 505		case 1UL:
 506			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 507			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
 508			break;
 509		case 2UL:
 510			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 511			child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
 512			break;
 513		default:
 514			return -EINVAL;
 515		}
 516		return 0;
 517	default:
 518		return ptrace_request(child, request, addr, data);
 519	}
 520}
 521
 522#ifdef CONFIG_COMPAT
 523/*
 524 * Now the fun part starts... a 31 bit program running in the
 525 * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 526 * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 527 * to handle, the difference to the 64 bit versions of the requests
 528 * is that the access is done in multiples of 4 byte instead of
 529 * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 530 * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 531 * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 532 * is a 31 bit program too, the content of struct user can be
 533 * emulated. A 31 bit program peeking into the struct user of
 534 * a 64 bit program is a no-no.
 535 */
 536
 537/*
 538 * Same as peek_user_per but for a 31 bit program.
 539 */
 540static inline __u32 __peek_user_per_compat(struct task_struct *child,
 541					   addr_t addr)
 542{
 543	struct compat_per_struct_kernel *dummy32 = NULL;
 544
 545	if (addr == (addr_t) &dummy32->cr9)
 546		/* Control bits of the active per set. */
 547		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 548			PER_EVENT_IFETCH : child->thread.per_user.control;
 549	else if (addr == (addr_t) &dummy32->cr10)
 550		/* Start address of the active per set. */
 551		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 552			0 : child->thread.per_user.start;
 553	else if (addr == (addr_t) &dummy32->cr11)
 554		/* End address of the active per set. */
 555		return test_thread_flag(TIF_SINGLE_STEP) ?
 556			PSW32_ADDR_INSN : child->thread.per_user.end;
 557	else if (addr == (addr_t) &dummy32->bits)
 558		/* Single-step bit. */
 559		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 560			0x80000000 : 0;
 561	else if (addr == (addr_t) &dummy32->starting_addr)
 562		/* Start address of the user specified per set. */
 563		return (__u32) child->thread.per_user.start;
 564	else if (addr == (addr_t) &dummy32->ending_addr)
 565		/* End address of the user specified per set. */
 566		return (__u32) child->thread.per_user.end;
 567	else if (addr == (addr_t) &dummy32->perc_atmid)
 568		/* PER code, ATMID and AI of the last PER trap */
 569		return (__u32) child->thread.per_event.cause << 16;
 570	else if (addr == (addr_t) &dummy32->address)
 571		/* Address of the last PER trap */
 572		return (__u32) child->thread.per_event.address;
 573	else if (addr == (addr_t) &dummy32->access_id)
 574		/* Access id of the last PER trap */
 575		return (__u32) child->thread.per_event.paid << 24;
 576	return 0;
 577}
 578
 579/*
 580 * Same as peek_user but for a 31 bit program.
 581 */
 582static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 583{
 584	struct compat_user *dummy32 = NULL;
 585	addr_t offset;
 586	__u32 tmp;
 587
 588	if (addr < (addr_t) &dummy32->regs.acrs) {
 589		struct pt_regs *regs = task_pt_regs(child);
 590		/*
 591		 * psw and gprs are stored on the stack
 592		 */
 593		if (addr == (addr_t) &dummy32->regs.psw.mask) {
 594			/* Fake a 31 bit psw mask. */
 595			tmp = (__u32)(regs->psw.mask >> 32);
 596			tmp &= PSW32_MASK_USER | PSW32_MASK_RI;
 597			tmp |= PSW32_USER_BITS;
 598		} else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 599			/* Fake a 31 bit psw address. */
 600			tmp = (__u32) regs->psw.addr |
 601				(__u32)(regs->psw.mask & PSW_MASK_BA);
 602		} else {
 603			/* gpr 0-15 */
 604			tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
 605		}
 606	} else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 607		/*
 608		 * access registers are stored in the thread structure
 609		 */
 610		offset = addr - (addr_t) &dummy32->regs.acrs;
 611		tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 612
 613	} else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 614		/*
 615		 * orig_gpr2 is stored on the kernel stack
 616		 */
 617		tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 618
 619	} else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 620		/*
 621		 * prevent reads of padding hole between
 622		 * orig_gpr2 and fp_regs on s390.
 623		 */
 624		tmp = 0;
 625
 626	} else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
 627		/*
 628		 * floating point control reg. is in the thread structure
 629		 */
 630		tmp = child->thread.fpu.fpc;
 631
 632	} else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 633		/*
 634		 * floating point regs. are either in child->thread.fpu
 635		 * or the child->thread.fpu.vxrs array
 636		 */
 637		offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
 638		if (MACHINE_HAS_VX)
 639			tmp = *(__u32 *)
 640			       ((addr_t) child->thread.fpu.vxrs + 2*offset);
 641		else
 642			tmp = *(__u32 *)
 643			       ((addr_t) child->thread.fpu.fprs + offset);
 644
 645	} else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 646		/*
 647		 * Handle access to the per_info structure.
 648		 */
 649		addr -= (addr_t) &dummy32->regs.per_info;
 650		tmp = __peek_user_per_compat(child, addr);
 651
 652	} else
 653		tmp = 0;
 654
 655	return tmp;
 656}
 657
 658static int peek_user_compat(struct task_struct *child,
 659			    addr_t addr, addr_t data)
 660{
 661	__u32 tmp;
 662
 663	if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
 664		return -EIO;
 665
 666	tmp = __peek_user_compat(child, addr);
 667	return put_user(tmp, (__u32 __user *) data);
 668}
 669
 670/*
 671 * Same as poke_user_per but for a 31 bit program.
 672 */
 673static inline void __poke_user_per_compat(struct task_struct *child,
 674					  addr_t addr, __u32 data)
 675{
 676	struct compat_per_struct_kernel *dummy32 = NULL;
 677
 678	if (addr == (addr_t) &dummy32->cr9)
 679		/* PER event mask of the user specified per set. */
 680		child->thread.per_user.control =
 681			data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 682	else if (addr == (addr_t) &dummy32->starting_addr)
 683		/* Starting address of the user specified per set. */
 684		child->thread.per_user.start = data;
 685	else if (addr == (addr_t) &dummy32->ending_addr)
 686		/* Ending address of the user specified per set. */
 687		child->thread.per_user.end = data;
 688}
 689
 690/*
 691 * Same as poke_user but for a 31 bit program.
 692 */
 693static int __poke_user_compat(struct task_struct *child,
 694			      addr_t addr, addr_t data)
 695{
 696	struct compat_user *dummy32 = NULL;
 697	__u32 tmp = (__u32) data;
 698	addr_t offset;
 699
 700	if (addr < (addr_t) &dummy32->regs.acrs) {
 701		struct pt_regs *regs = task_pt_regs(child);
 702		/*
 703		 * psw, gprs, acrs and orig_gpr2 are stored on the stack
 704		 */
 705		if (addr == (addr_t) &dummy32->regs.psw.mask) {
 706			__u32 mask = PSW32_MASK_USER;
 707
 708			mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
 709			/* Build a 64 bit psw mask from 31 bit mask. */
 710			if ((tmp ^ PSW32_USER_BITS) & ~mask)
 711				/* Invalid psw mask. */
 712				return -EINVAL;
 713			if ((data & PSW32_MASK_ASC) == PSW32_ASC_HOME)
 714				/* Invalid address-space-control bits */
 715				return -EINVAL;
 716			regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
 717				(regs->psw.mask & PSW_MASK_BA) |
 718				(__u64)(tmp & mask) << 32;
 719		} else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 720			/* Build a 64 bit psw address from 31 bit address. */
 721			regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
 722			/* Transfer 31 bit amode bit to psw mask. */
 723			regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
 724				(__u64)(tmp & PSW32_ADDR_AMODE);
 725		} else {
 726			if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
 727				addr == offsetof(struct compat_user, regs.gprs[2])) {
 728				struct pt_regs *regs = task_pt_regs(child);
 729
 730				regs->int_code = 0x20000 | (data & 0xffff);
 731			}
 732			/* gpr 0-15 */
 733			*(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
 734		}
 735	} else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 736		/*
 737		 * access registers are stored in the thread structure
 738		 */
 739		offset = addr - (addr_t) &dummy32->regs.acrs;
 740		*(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 741
 742	} else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 743		/*
 744		 * orig_gpr2 is stored on the kernel stack
 745		 */
 746		*(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 747
 748	} else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 749		/*
 750		 * prevent writess of padding hole between
 751		 * orig_gpr2 and fp_regs on s390.
 752		 */
 753		return 0;
 754
 755	} else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
 756		/*
 757		 * floating point control reg. is in the thread structure
 758		 */
 759		if (test_fp_ctl(tmp))
 760			return -EINVAL;
 761		child->thread.fpu.fpc = data;
 762
 763	} else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 764		/*
 765		 * floating point regs. are either in child->thread.fpu
 766		 * or the child->thread.fpu.vxrs array
 767		 */
 768		offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
 769		if (MACHINE_HAS_VX)
 770			*(__u32 *)((addr_t)
 771				child->thread.fpu.vxrs + 2*offset) = tmp;
 772		else
 773			*(__u32 *)((addr_t)
 774				child->thread.fpu.fprs + offset) = tmp;
 775
 776	} else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 777		/*
 778		 * Handle access to the per_info structure.
 779		 */
 780		addr -= (addr_t) &dummy32->regs.per_info;
 781		__poke_user_per_compat(child, addr, data);
 782	}
 783
 784	return 0;
 785}
 786
 787static int poke_user_compat(struct task_struct *child,
 788			    addr_t addr, addr_t data)
 789{
 790	if (!is_compat_task() || (addr & 3) ||
 791	    addr > sizeof(struct compat_user) - 3)
 792		return -EIO;
 793
 794	return __poke_user_compat(child, addr, data);
 795}
 796
 797long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 798			compat_ulong_t caddr, compat_ulong_t cdata)
 799{
 800	unsigned long addr = caddr;
 801	unsigned long data = cdata;
 802	compat_ptrace_area parea;
 803	int copied, ret;
 804
 805	switch (request) {
 806	case PTRACE_PEEKUSR:
 807		/* read the word at location addr in the USER area. */
 808		return peek_user_compat(child, addr, data);
 809
 810	case PTRACE_POKEUSR:
 811		/* write the word at location addr in the USER area */
 812		return poke_user_compat(child, addr, data);
 813
 814	case PTRACE_PEEKUSR_AREA:
 815	case PTRACE_POKEUSR_AREA:
 816		if (copy_from_user(&parea, (void __force __user *) addr,
 817							sizeof(parea)))
 818			return -EFAULT;
 819		addr = parea.kernel_addr;
 820		data = parea.process_addr;
 821		copied = 0;
 822		while (copied < parea.len) {
 823			if (request == PTRACE_PEEKUSR_AREA)
 824				ret = peek_user_compat(child, addr, data);
 825			else {
 826				__u32 utmp;
 827				if (get_user(utmp,
 828					     (__u32 __force __user *) data))
 829					return -EFAULT;
 830				ret = poke_user_compat(child, addr, utmp);
 831			}
 832			if (ret)
 833				return ret;
 834			addr += sizeof(unsigned int);
 835			data += sizeof(unsigned int);
 836			copied += sizeof(unsigned int);
 837		}
 838		return 0;
 839	case PTRACE_GET_LAST_BREAK:
 840		put_user(child->thread.last_break,
 841			 (unsigned int __user *) data);
 842		return 0;
 843	}
 844	return compat_ptrace_request(child, request, addr, data);
 845}
 846#endif
 847
 848/*
 849 * user_regset definitions.
 850 */
 851
 852static int s390_regs_get(struct task_struct *target,
 853			 const struct user_regset *regset,
 854			 struct membuf to)
 855{
 856	unsigned pos;
 857	if (target == current)
 858		save_access_regs(target->thread.acrs);
 859
 860	for (pos = 0; pos < sizeof(s390_regs); pos += sizeof(long))
 861		membuf_store(&to, __peek_user(target, pos));
 862	return 0;
 863}
 864
 865static int s390_regs_set(struct task_struct *target,
 866			 const struct user_regset *regset,
 867			 unsigned int pos, unsigned int count,
 868			 const void *kbuf, const void __user *ubuf)
 869{
 870	int rc = 0;
 871
 872	if (target == current)
 873		save_access_regs(target->thread.acrs);
 874
 875	if (kbuf) {
 876		const unsigned long *k = kbuf;
 877		while (count > 0 && !rc) {
 878			rc = __poke_user(target, pos, *k++);
 879			count -= sizeof(*k);
 880			pos += sizeof(*k);
 881		}
 882	} else {
 883		const unsigned long  __user *u = ubuf;
 884		while (count > 0 && !rc) {
 885			unsigned long word;
 886			rc = __get_user(word, u++);
 887			if (rc)
 888				break;
 889			rc = __poke_user(target, pos, word);
 890			count -= sizeof(*u);
 891			pos += sizeof(*u);
 892		}
 893	}
 894
 895	if (rc == 0 && target == current)
 896		restore_access_regs(target->thread.acrs);
 897
 898	return rc;
 899}
 900
 901static int s390_fpregs_get(struct task_struct *target,
 902			   const struct user_regset *regset,
 903			   struct membuf to)
 904{
 905	_s390_fp_regs fp_regs;
 906
 907	if (target == current)
 908		save_fpu_regs();
 909
 910	fp_regs.fpc = target->thread.fpu.fpc;
 911	fpregs_store(&fp_regs, &target->thread.fpu);
 912
 913	return membuf_write(&to, &fp_regs, sizeof(fp_regs));
 914}
 915
 916static int s390_fpregs_set(struct task_struct *target,
 917			   const struct user_regset *regset, unsigned int pos,
 918			   unsigned int count, const void *kbuf,
 919			   const void __user *ubuf)
 920{
 921	int rc = 0;
 922	freg_t fprs[__NUM_FPRS];
 923
 924	if (target == current)
 925		save_fpu_regs();
 926
 927	if (MACHINE_HAS_VX)
 928		convert_vx_to_fp(fprs, target->thread.fpu.vxrs);
 929	else
 930		memcpy(&fprs, target->thread.fpu.fprs, sizeof(fprs));
 931
 932	/* If setting FPC, must validate it first. */
 933	if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 934		u32 ufpc[2] = { target->thread.fpu.fpc, 0 };
 935		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
 936					0, offsetof(s390_fp_regs, fprs));
 937		if (rc)
 938			return rc;
 939		if (ufpc[1] != 0 || test_fp_ctl(ufpc[0]))
 940			return -EINVAL;
 941		target->thread.fpu.fpc = ufpc[0];
 942	}
 943
 944	if (rc == 0 && count > 0)
 945		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 946					fprs, offsetof(s390_fp_regs, fprs), -1);
 947	if (rc)
 948		return rc;
 949
 950	if (MACHINE_HAS_VX)
 951		convert_fp_to_vx(target->thread.fpu.vxrs, fprs);
 952	else
 953		memcpy(target->thread.fpu.fprs, &fprs, sizeof(fprs));
 954
 955	return rc;
 956}
 957
 958static int s390_last_break_get(struct task_struct *target,
 959			       const struct user_regset *regset,
 960			       struct membuf to)
 961{
 962	return membuf_store(&to, target->thread.last_break);
 963}
 964
 965static int s390_last_break_set(struct task_struct *target,
 966			       const struct user_regset *regset,
 967			       unsigned int pos, unsigned int count,
 968			       const void *kbuf, const void __user *ubuf)
 969{
 970	return 0;
 971}
 972
 973static int s390_tdb_get(struct task_struct *target,
 974			const struct user_regset *regset,
 975			struct membuf to)
 976{
 977	struct pt_regs *regs = task_pt_regs(target);
 978	size_t size;
 979
 980	if (!(regs->int_code & 0x200))
 981		return -ENODATA;
 982	size = sizeof(target->thread.trap_tdb.data);
 983	return membuf_write(&to, target->thread.trap_tdb.data, size);
 984}
 985
 986static int s390_tdb_set(struct task_struct *target,
 987			const struct user_regset *regset,
 988			unsigned int pos, unsigned int count,
 989			const void *kbuf, const void __user *ubuf)
 990{
 991	return 0;
 992}
 993
 994static int s390_vxrs_low_get(struct task_struct *target,
 995			     const struct user_regset *regset,
 996			     struct membuf to)
 997{
 998	__u64 vxrs[__NUM_VXRS_LOW];
 999	int i;
1000
1001	if (!MACHINE_HAS_VX)
1002		return -ENODEV;
1003	if (target == current)
1004		save_fpu_regs();
1005	for (i = 0; i < __NUM_VXRS_LOW; i++)
1006		vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1007	return membuf_write(&to, vxrs, sizeof(vxrs));
1008}
1009
1010static int s390_vxrs_low_set(struct task_struct *target,
1011			     const struct user_regset *regset,
1012			     unsigned int pos, unsigned int count,
1013			     const void *kbuf, const void __user *ubuf)
1014{
1015	__u64 vxrs[__NUM_VXRS_LOW];
1016	int i, rc;
1017
1018	if (!MACHINE_HAS_VX)
1019		return -ENODEV;
1020	if (target == current)
1021		save_fpu_regs();
1022
1023	for (i = 0; i < __NUM_VXRS_LOW; i++)
1024		vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1025
1026	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1027	if (rc == 0)
1028		for (i = 0; i < __NUM_VXRS_LOW; i++)
1029			*((__u64 *)(target->thread.fpu.vxrs + i) + 1) = vxrs[i];
1030
1031	return rc;
1032}
1033
1034static int s390_vxrs_high_get(struct task_struct *target,
1035			      const struct user_regset *regset,
1036			      struct membuf to)
1037{
1038	if (!MACHINE_HAS_VX)
1039		return -ENODEV;
1040	if (target == current)
1041		save_fpu_regs();
1042	return membuf_write(&to, target->thread.fpu.vxrs + __NUM_VXRS_LOW,
1043			    __NUM_VXRS_HIGH * sizeof(__vector128));
1044}
1045
1046static int s390_vxrs_high_set(struct task_struct *target,
1047			      const struct user_regset *regset,
1048			      unsigned int pos, unsigned int count,
1049			      const void *kbuf, const void __user *ubuf)
1050{
1051	int rc;
1052
1053	if (!MACHINE_HAS_VX)
1054		return -ENODEV;
1055	if (target == current)
1056		save_fpu_regs();
1057
1058	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1059				target->thread.fpu.vxrs + __NUM_VXRS_LOW, 0, -1);
1060	return rc;
1061}
1062
1063static int s390_system_call_get(struct task_struct *target,
1064				const struct user_regset *regset,
1065				struct membuf to)
1066{
1067	return membuf_store(&to, target->thread.system_call);
1068}
1069
1070static int s390_system_call_set(struct task_struct *target,
1071				const struct user_regset *regset,
1072				unsigned int pos, unsigned int count,
1073				const void *kbuf, const void __user *ubuf)
1074{
1075	unsigned int *data = &target->thread.system_call;
1076	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1077				  data, 0, sizeof(unsigned int));
1078}
1079
1080static int s390_gs_cb_get(struct task_struct *target,
1081			  const struct user_regset *regset,
1082			  struct membuf to)
1083{
1084	struct gs_cb *data = target->thread.gs_cb;
1085
1086	if (!MACHINE_HAS_GS)
1087		return -ENODEV;
1088	if (!data)
1089		return -ENODATA;
1090	if (target == current)
1091		save_gs_cb(data);
1092	return membuf_write(&to, data, sizeof(struct gs_cb));
1093}
1094
1095static int s390_gs_cb_set(struct task_struct *target,
1096			  const struct user_regset *regset,
1097			  unsigned int pos, unsigned int count,
1098			  const void *kbuf, const void __user *ubuf)
1099{
1100	struct gs_cb gs_cb = { }, *data = NULL;
1101	int rc;
1102
1103	if (!MACHINE_HAS_GS)
1104		return -ENODEV;
1105	if (!target->thread.gs_cb) {
1106		data = kzalloc(sizeof(*data), GFP_KERNEL);
1107		if (!data)
1108			return -ENOMEM;
1109	}
1110	if (!target->thread.gs_cb)
1111		gs_cb.gsd = 25;
1112	else if (target == current)
1113		save_gs_cb(&gs_cb);
1114	else
1115		gs_cb = *target->thread.gs_cb;
1116	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1117				&gs_cb, 0, sizeof(gs_cb));
1118	if (rc) {
1119		kfree(data);
1120		return -EFAULT;
1121	}
1122	preempt_disable();
1123	if (!target->thread.gs_cb)
1124		target->thread.gs_cb = data;
1125	*target->thread.gs_cb = gs_cb;
1126	if (target == current) {
1127		__ctl_set_bit(2, 4);
1128		restore_gs_cb(target->thread.gs_cb);
1129	}
1130	preempt_enable();
1131	return rc;
1132}
1133
1134static int s390_gs_bc_get(struct task_struct *target,
1135			  const struct user_regset *regset,
1136			  struct membuf to)
1137{
1138	struct gs_cb *data = target->thread.gs_bc_cb;
1139
1140	if (!MACHINE_HAS_GS)
1141		return -ENODEV;
1142	if (!data)
1143		return -ENODATA;
1144	return membuf_write(&to, data, sizeof(struct gs_cb));
1145}
1146
1147static int s390_gs_bc_set(struct task_struct *target,
1148			  const struct user_regset *regset,
1149			  unsigned int pos, unsigned int count,
1150			  const void *kbuf, const void __user *ubuf)
1151{
1152	struct gs_cb *data = target->thread.gs_bc_cb;
1153
1154	if (!MACHINE_HAS_GS)
1155		return -ENODEV;
1156	if (!data) {
1157		data = kzalloc(sizeof(*data), GFP_KERNEL);
1158		if (!data)
1159			return -ENOMEM;
1160		target->thread.gs_bc_cb = data;
1161	}
1162	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1163				  data, 0, sizeof(struct gs_cb));
1164}
1165
1166static bool is_ri_cb_valid(struct runtime_instr_cb *cb)
1167{
1168	return (cb->rca & 0x1f) == 0 &&
1169		(cb->roa & 0xfff) == 0 &&
1170		(cb->rla & 0xfff) == 0xfff &&
1171		cb->s == 1 &&
1172		cb->k == 1 &&
1173		cb->h == 0 &&
1174		cb->reserved1 == 0 &&
1175		cb->ps == 1 &&
1176		cb->qs == 0 &&
1177		cb->pc == 1 &&
1178		cb->qc == 0 &&
1179		cb->reserved2 == 0 &&
1180		cb->reserved3 == 0 &&
1181		cb->reserved4 == 0 &&
1182		cb->reserved5 == 0 &&
1183		cb->reserved6 == 0 &&
1184		cb->reserved7 == 0 &&
1185		cb->reserved8 == 0 &&
1186		cb->rla >= cb->roa &&
1187		cb->rca >= cb->roa &&
1188		cb->rca <= cb->rla+1 &&
1189		cb->m < 3;
1190}
1191
1192static int s390_runtime_instr_get(struct task_struct *target,
1193				const struct user_regset *regset,
1194				struct membuf to)
1195{
1196	struct runtime_instr_cb *data = target->thread.ri_cb;
1197
1198	if (!test_facility(64))
1199		return -ENODEV;
1200	if (!data)
1201		return -ENODATA;
1202
1203	return membuf_write(&to, data, sizeof(struct runtime_instr_cb));
1204}
1205
1206static int s390_runtime_instr_set(struct task_struct *target,
1207				  const struct user_regset *regset,
1208				  unsigned int pos, unsigned int count,
1209				  const void *kbuf, const void __user *ubuf)
1210{
1211	struct runtime_instr_cb ri_cb = { }, *data = NULL;
1212	int rc;
1213
1214	if (!test_facility(64))
1215		return -ENODEV;
1216
1217	if (!target->thread.ri_cb) {
1218		data = kzalloc(sizeof(*data), GFP_KERNEL);
1219		if (!data)
1220			return -ENOMEM;
1221	}
1222
1223	if (target->thread.ri_cb) {
1224		if (target == current)
1225			store_runtime_instr_cb(&ri_cb);
1226		else
1227			ri_cb = *target->thread.ri_cb;
1228	}
1229
1230	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1231				&ri_cb, 0, sizeof(struct runtime_instr_cb));
1232	if (rc) {
1233		kfree(data);
1234		return -EFAULT;
1235	}
1236
1237	if (!is_ri_cb_valid(&ri_cb)) {
1238		kfree(data);
1239		return -EINVAL;
1240	}
1241	/*
1242	 * Override access key in any case, since user space should
1243	 * not be able to set it, nor should it care about it.
1244	 */
1245	ri_cb.key = PAGE_DEFAULT_KEY >> 4;
1246	preempt_disable();
1247	if (!target->thread.ri_cb)
1248		target->thread.ri_cb = data;
1249	*target->thread.ri_cb = ri_cb;
1250	if (target == current)
1251		load_runtime_instr_cb(target->thread.ri_cb);
1252	preempt_enable();
1253
1254	return 0;
1255}
1256
1257static const struct user_regset s390_regsets[] = {
1258	{
1259		.core_note_type = NT_PRSTATUS,
1260		.n = sizeof(s390_regs) / sizeof(long),
1261		.size = sizeof(long),
1262		.align = sizeof(long),
1263		.regset_get = s390_regs_get,
1264		.set = s390_regs_set,
1265	},
1266	{
1267		.core_note_type = NT_PRFPREG,
1268		.n = sizeof(s390_fp_regs) / sizeof(long),
1269		.size = sizeof(long),
1270		.align = sizeof(long),
1271		.regset_get = s390_fpregs_get,
1272		.set = s390_fpregs_set,
1273	},
1274	{
1275		.core_note_type = NT_S390_SYSTEM_CALL,
1276		.n = 1,
1277		.size = sizeof(unsigned int),
1278		.align = sizeof(unsigned int),
1279		.regset_get = s390_system_call_get,
1280		.set = s390_system_call_set,
1281	},
1282	{
1283		.core_note_type = NT_S390_LAST_BREAK,
1284		.n = 1,
1285		.size = sizeof(long),
1286		.align = sizeof(long),
1287		.regset_get = s390_last_break_get,
1288		.set = s390_last_break_set,
1289	},
1290	{
1291		.core_note_type = NT_S390_TDB,
1292		.n = 1,
1293		.size = 256,
1294		.align = 1,
1295		.regset_get = s390_tdb_get,
1296		.set = s390_tdb_set,
1297	},
1298	{
1299		.core_note_type = NT_S390_VXRS_LOW,
1300		.n = __NUM_VXRS_LOW,
1301		.size = sizeof(__u64),
1302		.align = sizeof(__u64),
1303		.regset_get = s390_vxrs_low_get,
1304		.set = s390_vxrs_low_set,
1305	},
1306	{
1307		.core_note_type = NT_S390_VXRS_HIGH,
1308		.n = __NUM_VXRS_HIGH,
1309		.size = sizeof(__vector128),
1310		.align = sizeof(__vector128),
1311		.regset_get = s390_vxrs_high_get,
1312		.set = s390_vxrs_high_set,
1313	},
1314	{
1315		.core_note_type = NT_S390_GS_CB,
1316		.n = sizeof(struct gs_cb) / sizeof(__u64),
1317		.size = sizeof(__u64),
1318		.align = sizeof(__u64),
1319		.regset_get = s390_gs_cb_get,
1320		.set = s390_gs_cb_set,
1321	},
1322	{
1323		.core_note_type = NT_S390_GS_BC,
1324		.n = sizeof(struct gs_cb) / sizeof(__u64),
1325		.size = sizeof(__u64),
1326		.align = sizeof(__u64),
1327		.regset_get = s390_gs_bc_get,
1328		.set = s390_gs_bc_set,
1329	},
1330	{
1331		.core_note_type = NT_S390_RI_CB,
1332		.n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1333		.size = sizeof(__u64),
1334		.align = sizeof(__u64),
1335		.regset_get = s390_runtime_instr_get,
1336		.set = s390_runtime_instr_set,
1337	},
1338};
1339
1340static const struct user_regset_view user_s390_view = {
1341	.name = "s390x",
1342	.e_machine = EM_S390,
1343	.regsets = s390_regsets,
1344	.n = ARRAY_SIZE(s390_regsets)
1345};
1346
1347#ifdef CONFIG_COMPAT
1348static int s390_compat_regs_get(struct task_struct *target,
1349				const struct user_regset *regset,
1350				struct membuf to)
1351{
1352	unsigned n;
1353
1354	if (target == current)
1355		save_access_regs(target->thread.acrs);
1356
1357	for (n = 0; n < sizeof(s390_compat_regs); n += sizeof(compat_ulong_t))
1358		membuf_store(&to, __peek_user_compat(target, n));
1359	return 0;
1360}
1361
1362static int s390_compat_regs_set(struct task_struct *target,
1363				const struct user_regset *regset,
1364				unsigned int pos, unsigned int count,
1365				const void *kbuf, const void __user *ubuf)
1366{
1367	int rc = 0;
1368
1369	if (target == current)
1370		save_access_regs(target->thread.acrs);
1371
1372	if (kbuf) {
1373		const compat_ulong_t *k = kbuf;
1374		while (count > 0 && !rc) {
1375			rc = __poke_user_compat(target, pos, *k++);
1376			count -= sizeof(*k);
1377			pos += sizeof(*k);
1378		}
1379	} else {
1380		const compat_ulong_t  __user *u = ubuf;
1381		while (count > 0 && !rc) {
1382			compat_ulong_t word;
1383			rc = __get_user(word, u++);
1384			if (rc)
1385				break;
1386			rc = __poke_user_compat(target, pos, word);
1387			count -= sizeof(*u);
1388			pos += sizeof(*u);
1389		}
1390	}
1391
1392	if (rc == 0 && target == current)
1393		restore_access_regs(target->thread.acrs);
1394
1395	return rc;
1396}
1397
1398static int s390_compat_regs_high_get(struct task_struct *target,
1399				     const struct user_regset *regset,
1400				     struct membuf to)
1401{
1402	compat_ulong_t *gprs_high;
1403	int i;
1404
1405	gprs_high = (compat_ulong_t *)task_pt_regs(target)->gprs;
1406	for (i = 0; i < NUM_GPRS; i++, gprs_high += 2)
1407		membuf_store(&to, *gprs_high);
1408	return 0;
1409}
1410
1411static int s390_compat_regs_high_set(struct task_struct *target,
1412				     const struct user_regset *regset,
1413				     unsigned int pos, unsigned int count,
1414				     const void *kbuf, const void __user *ubuf)
1415{
1416	compat_ulong_t *gprs_high;
1417	int rc = 0;
1418
1419	gprs_high = (compat_ulong_t *)
1420		&task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1421	if (kbuf) {
1422		const compat_ulong_t *k = kbuf;
1423		while (count > 0) {
1424			*gprs_high = *k++;
1425			*gprs_high += 2;
1426			count -= sizeof(*k);
1427		}
1428	} else {
1429		const compat_ulong_t  __user *u = ubuf;
1430		while (count > 0 && !rc) {
1431			unsigned long word;
1432			rc = __get_user(word, u++);
1433			if (rc)
1434				break;
1435			*gprs_high = word;
1436			*gprs_high += 2;
1437			count -= sizeof(*u);
1438		}
1439	}
1440
1441	return rc;
1442}
1443
1444static int s390_compat_last_break_get(struct task_struct *target,
1445				      const struct user_regset *regset,
1446				      struct membuf to)
1447{
1448	compat_ulong_t last_break = target->thread.last_break;
1449
1450	return membuf_store(&to, (unsigned long)last_break);
1451}
1452
1453static int s390_compat_last_break_set(struct task_struct *target,
1454				      const struct user_regset *regset,
1455				      unsigned int pos, unsigned int count,
1456				      const void *kbuf, const void __user *ubuf)
1457{
1458	return 0;
1459}
1460
1461static const struct user_regset s390_compat_regsets[] = {
1462	{
1463		.core_note_type = NT_PRSTATUS,
1464		.n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1465		.size = sizeof(compat_long_t),
1466		.align = sizeof(compat_long_t),
1467		.regset_get = s390_compat_regs_get,
1468		.set = s390_compat_regs_set,
1469	},
1470	{
1471		.core_note_type = NT_PRFPREG,
1472		.n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1473		.size = sizeof(compat_long_t),
1474		.align = sizeof(compat_long_t),
1475		.regset_get = s390_fpregs_get,
1476		.set = s390_fpregs_set,
1477	},
1478	{
1479		.core_note_type = NT_S390_SYSTEM_CALL,
1480		.n = 1,
1481		.size = sizeof(compat_uint_t),
1482		.align = sizeof(compat_uint_t),
1483		.regset_get = s390_system_call_get,
1484		.set = s390_system_call_set,
1485	},
1486	{
1487		.core_note_type = NT_S390_LAST_BREAK,
1488		.n = 1,
1489		.size = sizeof(long),
1490		.align = sizeof(long),
1491		.regset_get = s390_compat_last_break_get,
1492		.set = s390_compat_last_break_set,
1493	},
1494	{
1495		.core_note_type = NT_S390_TDB,
1496		.n = 1,
1497		.size = 256,
1498		.align = 1,
1499		.regset_get = s390_tdb_get,
1500		.set = s390_tdb_set,
1501	},
1502	{
1503		.core_note_type = NT_S390_VXRS_LOW,
1504		.n = __NUM_VXRS_LOW,
1505		.size = sizeof(__u64),
1506		.align = sizeof(__u64),
1507		.regset_get = s390_vxrs_low_get,
1508		.set = s390_vxrs_low_set,
1509	},
1510	{
1511		.core_note_type = NT_S390_VXRS_HIGH,
1512		.n = __NUM_VXRS_HIGH,
1513		.size = sizeof(__vector128),
1514		.align = sizeof(__vector128),
1515		.regset_get = s390_vxrs_high_get,
1516		.set = s390_vxrs_high_set,
1517	},
1518	{
1519		.core_note_type = NT_S390_HIGH_GPRS,
1520		.n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1521		.size = sizeof(compat_long_t),
1522		.align = sizeof(compat_long_t),
1523		.regset_get = s390_compat_regs_high_get,
1524		.set = s390_compat_regs_high_set,
1525	},
1526	{
1527		.core_note_type = NT_S390_GS_CB,
1528		.n = sizeof(struct gs_cb) / sizeof(__u64),
1529		.size = sizeof(__u64),
1530		.align = sizeof(__u64),
1531		.regset_get = s390_gs_cb_get,
1532		.set = s390_gs_cb_set,
1533	},
1534	{
1535		.core_note_type = NT_S390_GS_BC,
1536		.n = sizeof(struct gs_cb) / sizeof(__u64),
1537		.size = sizeof(__u64),
1538		.align = sizeof(__u64),
1539		.regset_get = s390_gs_bc_get,
1540		.set = s390_gs_bc_set,
1541	},
1542	{
1543		.core_note_type = NT_S390_RI_CB,
1544		.n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1545		.size = sizeof(__u64),
1546		.align = sizeof(__u64),
1547		.regset_get = s390_runtime_instr_get,
1548		.set = s390_runtime_instr_set,
1549	},
1550};
1551
1552static const struct user_regset_view user_s390_compat_view = {
1553	.name = "s390",
1554	.e_machine = EM_S390,
1555	.regsets = s390_compat_regsets,
1556	.n = ARRAY_SIZE(s390_compat_regsets)
1557};
1558#endif
1559
1560const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1561{
1562#ifdef CONFIG_COMPAT
1563	if (test_tsk_thread_flag(task, TIF_31BIT))
1564		return &user_s390_compat_view;
1565#endif
1566	return &user_s390_view;
1567}
1568
1569static const char *gpr_names[NUM_GPRS] = {
1570	"r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1571	"r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1572};
1573
1574unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1575{
1576	if (offset >= NUM_GPRS)
1577		return 0;
1578	return regs->gprs[offset];
1579}
1580
1581int regs_query_register_offset(const char *name)
1582{
1583	unsigned long offset;
1584
1585	if (!name || *name != 'r')
1586		return -EINVAL;
1587	if (kstrtoul(name + 1, 10, &offset))
1588		return -EINVAL;
1589	if (offset >= NUM_GPRS)
1590		return -EINVAL;
1591	return offset;
1592}
1593
1594const char *regs_query_register_name(unsigned int offset)
1595{
1596	if (offset >= NUM_GPRS)
1597		return NULL;
1598	return gpr_names[offset];
1599}
1600
1601static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1602{
1603	unsigned long ksp = kernel_stack_pointer(regs);
1604
1605	return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1606}
1607
1608/**
1609 * regs_get_kernel_stack_nth() - get Nth entry of the stack
1610 * @regs:pt_regs which contains kernel stack pointer.
1611 * @n:stack entry number.
1612 *
1613 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1614 * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1615 * this returns 0.
1616 */
1617unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1618{
1619	unsigned long addr;
1620
1621	addr = kernel_stack_pointer(regs) + n * sizeof(long);
1622	if (!regs_within_kernel_stack(regs, addr))
1623		return 0;
1624	return *(unsigned long *)addr;
1625}