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