Initial import

1 files changed, 1533 insertions, 0 deletions

diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
new file mode 100644
index 000000000..d363c9c32
--- /dev/null
+++ b/arch/s390/kernel/ptrace.c
@@ -0,0 +1,1533 @@
+/*
+ *  Ptrace user space interface.
+ *
+ *    Copyright IBM Corp. 1999, 2010
+ *    Author(s): Denis Joseph Barrow
+ *               Martin Schwidefsky (schwidefsky@de.ibm.com)
+ */
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/errno.h>
+#include <linux/ptrace.h>
+#include <linux/user.h>
+#include <linux/security.h>
+#include <linux/audit.h>
+#include <linux/signal.h>
+#include <linux/elf.h>
+#include <linux/regset.h>
+#include <linux/tracehook.h>
+#include <linux/seccomp.h>
+#include <linux/compat.h>
+#include <trace/syscall.h>
+#include <asm/segment.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/uaccess.h>
+#include <asm/unistd.h>
+#include <asm/switch_to.h>
+#include "entry.h"
+
+#ifdef CONFIG_COMPAT
+#include "compat_ptrace.h"
+#endif
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/syscalls.h>
+
+void update_cr_regs(struct task_struct *task)
+{
+	struct pt_regs *regs = task_pt_regs(task);
+	struct thread_struct *thread = &task->thread;
+	struct per_regs old, new;
+
+	/* Take care of the enable/disable of transactional execution. */
+	if (MACHINE_HAS_TE || MACHINE_HAS_VX) {
+		unsigned long cr, cr_new;
+
+		__ctl_store(cr, 0, 0);
+		cr_new = cr;
+		if (MACHINE_HAS_TE) {
+			/* Set or clear transaction execution TXC bit 8. */
+			cr_new |= (1UL << 55);
+			if (task->thread.per_flags & PER_FLAG_NO_TE)
+				cr_new &= ~(1UL << 55);
+		}
+		if (MACHINE_HAS_VX) {
+			/* Enable/disable of vector extension */
+			cr_new &= ~(1UL << 17);
+			if (task->thread.vxrs)
+				cr_new |= (1UL << 17);
+		}
+		if (cr_new != cr)
+			__ctl_load(cr_new, 0, 0);
+		if (MACHINE_HAS_TE) {
+			/* Set/clear transaction execution TDC bits 62/63. */
+			__ctl_store(cr, 2, 2);
+			cr_new = cr & ~3UL;
+			if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
+				if (task->thread.per_flags &
+				    PER_FLAG_TE_ABORT_RAND_TEND)
+					cr_new |= 1UL;
+				else
+					cr_new |= 2UL;
+			}
+			if (cr_new != cr)
+				__ctl_load(cr_new, 2, 2);
+		}
+	}
+	/* Copy user specified PER registers */
+	new.control = thread->per_user.control;
+	new.start = thread->per_user.start;
+	new.end = thread->per_user.end;
+
+	/* merge TIF_SINGLE_STEP into user specified PER registers. */
+	if (test_tsk_thread_flag(task, TIF_SINGLE_STEP) ||
+	    test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP)) {
+		if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))
+			new.control |= PER_EVENT_BRANCH;
+		else
+			new.control |= PER_EVENT_IFETCH;
+		new.control |= PER_CONTROL_SUSPENSION;
+		new.control |= PER_EVENT_TRANSACTION_END;
+		if (test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP))
+			new.control |= PER_EVENT_IFETCH;
+		new.start = 0;
+		new.end = PSW_ADDR_INSN;
+	}
+
+	/* Take care of the PER enablement bit in the PSW. */
+	if (!(new.control & PER_EVENT_MASK)) {
+		regs->psw.mask &= ~PSW_MASK_PER;
+		return;
+	}
+	regs->psw.mask |= PSW_MASK_PER;
+	__ctl_store(old, 9, 11);
+	if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
+		__ctl_load(new, 9, 11);
+}
+
+void user_enable_single_step(struct task_struct *task)
+{
+	clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
+	set_tsk_thread_flag(task, TIF_SINGLE_STEP);
+}
+
+void user_disable_single_step(struct task_struct *task)
+{
+	clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
+	clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
+}
+
+void user_enable_block_step(struct task_struct *task)
+{
+	set_tsk_thread_flag(task, TIF_SINGLE_STEP);
+	set_tsk_thread_flag(task, TIF_BLOCK_STEP);
+}
+
+/*
+ * Called by kernel/ptrace.c when detaching..
+ *
+ * Clear all debugging related fields.
+ */
+void ptrace_disable(struct task_struct *task)
+{
+	memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
+	memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
+	clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
+	clear_pt_regs_flag(task_pt_regs(task), PIF_PER_TRAP);
+	task->thread.per_flags = 0;
+}
+
+#define __ADDR_MASK 7
+
+static inline unsigned long __peek_user_per(struct task_struct *child,
+					    addr_t addr)
+{
+	struct per_struct_kernel *dummy = NULL;
+
+	if (addr == (addr_t) &dummy->cr9)
+		/* Control bits of the active per set. */
+		return test_thread_flag(TIF_SINGLE_STEP) ?
+			PER_EVENT_IFETCH : child->thread.per_user.control;
+	else if (addr == (addr_t) &dummy->cr10)
+		/* Start address of the active per set. */
+		return test_thread_flag(TIF_SINGLE_STEP) ?
+			0 : child->thread.per_user.start;
+	else if (addr == (addr_t) &dummy->cr11)
+		/* End address of the active per set. */
+		return test_thread_flag(TIF_SINGLE_STEP) ?
+			PSW_ADDR_INSN : child->thread.per_user.end;
+	else if (addr == (addr_t) &dummy->bits)
+		/* Single-step bit. */
+		return test_thread_flag(TIF_SINGLE_STEP) ?
+			(1UL << (BITS_PER_LONG - 1)) : 0;
+	else if (addr == (addr_t) &dummy->starting_addr)
+		/* Start address of the user specified per set. */
+		return child->thread.per_user.start;
+	else if (addr == (addr_t) &dummy->ending_addr)
+		/* End address of the user specified per set. */
+		return child->thread.per_user.end;
+	else if (addr == (addr_t) &dummy->perc_atmid)
+		/* PER code, ATMID and AI of the last PER trap */
+		return (unsigned long)
+			child->thread.per_event.cause << (BITS_PER_LONG - 16);
+	else if (addr == (addr_t) &dummy->address)
+		/* Address of the last PER trap */
+		return child->thread.per_event.address;
+	else if (addr == (addr_t) &dummy->access_id)
+		/* Access id of the last PER trap */
+		return (unsigned long)
+			child->thread.per_event.paid << (BITS_PER_LONG - 8);
+	return 0;
+}
+
+/*
+ * Read the word at offset addr from the user area of a process. The
+ * trouble here is that the information is littered over different
+ * locations. The process registers are found on the kernel stack,
+ * the floating point stuff and the trace settings are stored in
+ * the task structure. In addition the different structures in
+ * struct user contain pad bytes that should be read as zeroes.
+ * Lovely...
+ */
+static unsigned long __peek_user(struct task_struct *child, addr_t addr)
+{
+	struct user *dummy = NULL;
+	addr_t offset, tmp;
+
+	if (addr < (addr_t) &dummy->regs.acrs) {
+		/*
+		 * psw and gprs are stored on the stack
+		 */
+		tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
+		if (addr == (addr_t) &dummy->regs.psw.mask) {
+			/* Return a clean psw mask. */
+			tmp &= PSW_MASK_USER | PSW_MASK_RI;
+			tmp |= PSW_USER_BITS;
+		}
+
+	} else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
+		/*
+		 * access registers are stored in the thread structure
+		 */
+		offset = addr - (addr_t) &dummy->regs.acrs;
+		/*
+		 * Very special case: old & broken 64 bit gdb reading
+		 * from acrs[15]. Result is a 64 bit value. Read the
+		 * 32 bit acrs[15] value and shift it by 32. Sick...
+		 */
+		if (addr == (addr_t) &dummy->regs.acrs[15])
+			tmp = ((unsigned long) child->thread.acrs[15]) << 32;
+		else
+			tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
+
+	} else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
+		/*
+		 * orig_gpr2 is stored on the kernel stack
+		 */
+		tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
+
+	} else if (addr < (addr_t) &dummy->regs.fp_regs) {
+		/*
+		 * prevent reads of padding hole between
+		 * orig_gpr2 and fp_regs on s390.
+		 */
+		tmp = 0;
+
+	} else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
+		/*
+		 * floating point control reg. is in the thread structure
+		 */
+		tmp = child->thread.fp_regs.fpc;
+		tmp <<= BITS_PER_LONG - 32;
+
+	} else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
+		/*
+		 * floating point regs. are either in child->thread.fp_regs
+		 * or the child->thread.vxrs array
+		 */
+		offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
+		if (child->thread.vxrs)
+			tmp = *(addr_t *)
+			       ((addr_t) child->thread.vxrs + 2*offset);
+		else
+			tmp = *(addr_t *)
+			       ((addr_t) &child->thread.fp_regs.fprs + offset);
+
+	} else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
+		/*
+		 * Handle access to the per_info structure.
+		 */
+		addr -= (addr_t) &dummy->regs.per_info;
+		tmp = __peek_user_per(child, addr);
+
+	} else
+		tmp = 0;
+
+	return tmp;
+}
+
+static int
+peek_user(struct task_struct *child, addr_t addr, addr_t data)
+{
+	addr_t tmp, mask;
+
+	/*
+	 * Stupid gdb peeks/pokes the access registers in 64 bit with
+	 * an alignment of 4. Programmers from hell...
+	 */
+	mask = __ADDR_MASK;
+	if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
+	    addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
+		mask = 3;
+	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
+		return -EIO;
+
+	tmp = __peek_user(child, addr);
+	return put_user(tmp, (addr_t __user *) data);
+}
+
+static inline void __poke_user_per(struct task_struct *child,
+				   addr_t addr, addr_t data)
+{
+	struct per_struct_kernel *dummy = NULL;
+
+	/*
+	 * There are only three fields in the per_info struct that the
+	 * debugger user can write to.
+	 * 1) cr9: the debugger wants to set a new PER event mask
+	 * 2) starting_addr: the debugger wants to set a new starting
+	 *    address to use with the PER event mask.
+	 * 3) ending_addr: the debugger wants to set a new ending
+	 *    address to use with the PER event mask.
+	 * The user specified PER event mask and the start and end
+	 * addresses are used only if single stepping is not in effect.
+	 * Writes to any other field in per_info are ignored.
+	 */
+	if (addr == (addr_t) &dummy->cr9)
+		/* PER event mask of the user specified per set. */
+		child->thread.per_user.control =
+			data & (PER_EVENT_MASK | PER_CONTROL_MASK);
+	else if (addr == (addr_t) &dummy->starting_addr)
+		/* Starting address of the user specified per set. */
+		child->thread.per_user.start = data;
+	else if (addr == (addr_t) &dummy->ending_addr)
+		/* Ending address of the user specified per set. */
+		child->thread.per_user.end = data;
+}
+
+/*
+ * Write a word to the user area of a process at location addr. This
+ * operation does have an additional problem compared to peek_user.
+ * Stores to the program status word and on the floating point
+ * control register needs to get checked for validity.
+ */
+static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
+{
+	struct user *dummy = NULL;
+	addr_t offset;
+
+	if (addr < (addr_t) &dummy->regs.acrs) {
+		/*
+		 * psw and gprs are stored on the stack
+		 */
+		if (addr == (addr_t) &dummy->regs.psw.mask) {
+			unsigned long mask = PSW_MASK_USER;
+
+			mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
+			if ((data ^ PSW_USER_BITS) & ~mask)
+				/* Invalid psw mask. */
+				return -EINVAL;
+			if ((data & PSW_MASK_ASC) == PSW_ASC_HOME)
+				/* Invalid address-space-control bits */
+				return -EINVAL;
+			if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
+				/* Invalid addressing mode bits */
+				return -EINVAL;
+		}
+		*(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
+
+	} else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
+		/*
+		 * access registers are stored in the thread structure
+		 */
+		offset = addr - (addr_t) &dummy->regs.acrs;
+		/*
+		 * Very special case: old & broken 64 bit gdb writing
+		 * to acrs[15] with a 64 bit value. Ignore the lower
+		 * half of the value and write the upper 32 bit to
+		 * acrs[15]. Sick...
+		 */
+		if (addr == (addr_t) &dummy->regs.acrs[15])
+			child->thread.acrs[15] = (unsigned int) (data >> 32);
+		else
+			*(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
+
+	} else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
+		/*
+		 * orig_gpr2 is stored on the kernel stack
+		 */
+		task_pt_regs(child)->orig_gpr2 = data;
+
+	} else if (addr < (addr_t) &dummy->regs.fp_regs) {
+		/*
+		 * prevent writes of padding hole between
+		 * orig_gpr2 and fp_regs on s390.
+		 */
+		return 0;
+
+	} else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
+		/*
+		 * floating point control reg. is in the thread structure
+		 */
+		if ((unsigned int) data != 0 ||
+		    test_fp_ctl(data >> (BITS_PER_LONG - 32)))
+			return -EINVAL;
+		child->thread.fp_regs.fpc = data >> (BITS_PER_LONG - 32);
+
+	} else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
+		/*
+		 * floating point regs. are either in child->thread.fp_regs
+		 * or the child->thread.vxrs array
+		 */
+		offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
+		if (child->thread.vxrs)
+			*(addr_t *)((addr_t)
+				child->thread.vxrs + 2*offset) = data;
+		else
+			*(addr_t *)((addr_t)
+				&child->thread.fp_regs.fprs + offset) = data;
+
+	} else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
+		/*
+		 * Handle access to the per_info structure.
+		 */
+		addr -= (addr_t) &dummy->regs.per_info;
+		__poke_user_per(child, addr, data);
+
+	}
+
+	return 0;
+}
+
+static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
+{
+	addr_t mask;
+
+	/*
+	 * Stupid gdb peeks/pokes the access registers in 64 bit with
+	 * an alignment of 4. Programmers from hell indeed...
+	 */
+	mask = __ADDR_MASK;
+	if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
+	    addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
+		mask = 3;
+	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
+		return -EIO;
+
+	return __poke_user(child, addr, data);
+}
+
+long arch_ptrace(struct task_struct *child, long request,
+		 unsigned long addr, unsigned long data)
+{
+	ptrace_area parea; 
+	int copied, ret;
+
+	switch (request) {
+	case PTRACE_PEEKUSR:
+		/* read the word at location addr in the USER area. */
+		return peek_user(child, addr, data);
+
+	case PTRACE_POKEUSR:
+		/* write the word at location addr in the USER area */
+		return poke_user(child, addr, data);
+
+	case PTRACE_PEEKUSR_AREA:
+	case PTRACE_POKEUSR_AREA:
+		if (copy_from_user(&parea, (void __force __user *) addr,
+							sizeof(parea)))
+			return -EFAULT;
+		addr = parea.kernel_addr;
+		data = parea.process_addr;
+		copied = 0;
+		while (copied < parea.len) {
+			if (request == PTRACE_PEEKUSR_AREA)
+				ret = peek_user(child, addr, data);
+			else {
+				addr_t utmp;
+				if (get_user(utmp,
+					     (addr_t __force __user *) data))
+					return -EFAULT;
+				ret = poke_user(child, addr, utmp);
+			}
+			if (ret)
+				return ret;
+			addr += sizeof(unsigned long);
+			data += sizeof(unsigned long);
+			copied += sizeof(unsigned long);
+		}
+		return 0;
+	case PTRACE_GET_LAST_BREAK:
+		put_user(task_thread_info(child)->last_break,
+			 (unsigned long __user *) data);
+		return 0;
+	case PTRACE_ENABLE_TE:
+		if (!MACHINE_HAS_TE)
+			return -EIO;
+		child->thread.per_flags &= ~PER_FLAG_NO_TE;
+		return 0;
+	case PTRACE_DISABLE_TE:
+		if (!MACHINE_HAS_TE)
+			return -EIO;
+		child->thread.per_flags |= PER_FLAG_NO_TE;
+		child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
+		return 0;
+	case PTRACE_TE_ABORT_RAND:
+		if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
+			return -EIO;
+		switch (data) {
+		case 0UL:
+			child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
+			break;
+		case 1UL:
+			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
+			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
+			break;
+		case 2UL:
+			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
+			child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
+			break;
+		default:
+			return -EINVAL;
+		}
+		return 0;
+	default:
+		/* Removing high order bit from addr (only for 31 bit). */
+		addr &= PSW_ADDR_INSN;
+		return ptrace_request(child, request, addr, data);
+	}
+}
+
+#ifdef CONFIG_COMPAT
+/*
+ * Now the fun part starts... a 31 bit program running in the
+ * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
+ * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
+ * to handle, the difference to the 64 bit versions of the requests
+ * is that the access is done in multiples of 4 byte instead of
+ * 8 bytes (sizeof(unsigned long) on 31/64 bit).
+ * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
+ * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
+ * is a 31 bit program too, the content of struct user can be
+ * emulated. A 31 bit program peeking into the struct user of
+ * a 64 bit program is a no-no.
+ */
+
+/*
+ * Same as peek_user_per but for a 31 bit program.
+ */
+static inline __u32 __peek_user_per_compat(struct task_struct *child,
+					   addr_t addr)
+{
+	struct compat_per_struct_kernel *dummy32 = NULL;
+
+	if (addr == (addr_t) &dummy32->cr9)
+		/* Control bits of the active per set. */
+		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
+			PER_EVENT_IFETCH : child->thread.per_user.control;
+	else if (addr == (addr_t) &dummy32->cr10)
+		/* Start address of the active per set. */
+		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
+			0 : child->thread.per_user.start;
+	else if (addr == (addr_t) &dummy32->cr11)
+		/* End address of the active per set. */
+		return test_thread_flag(TIF_SINGLE_STEP) ?
+			PSW32_ADDR_INSN : child->thread.per_user.end;
+	else if (addr == (addr_t) &dummy32->bits)
+		/* Single-step bit. */
+		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
+			0x80000000 : 0;
+	else if (addr == (addr_t) &dummy32->starting_addr)
+		/* Start address of the user specified per set. */
+		return (__u32) child->thread.per_user.start;
+	else if (addr == (addr_t) &dummy32->ending_addr)
+		/* End address of the user specified per set. */
+		return (__u32) child->thread.per_user.end;
+	else if (addr == (addr_t) &dummy32->perc_atmid)
+		/* PER code, ATMID and AI of the last PER trap */
+		return (__u32) child->thread.per_event.cause << 16;
+	else if (addr == (addr_t) &dummy32->address)
+		/* Address of the last PER trap */
+		return (__u32) child->thread.per_event.address;
+	else if (addr == (addr_t) &dummy32->access_id)
+		/* Access id of the last PER trap */
+		return (__u32) child->thread.per_event.paid << 24;
+	return 0;
+}
+
+/*
+ * Same as peek_user but for a 31 bit program.
+ */
+static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
+{
+	struct compat_user *dummy32 = NULL;
+	addr_t offset;
+	__u32 tmp;
+
+	if (addr < (addr_t) &dummy32->regs.acrs) {
+		struct pt_regs *regs = task_pt_regs(child);
+		/*
+		 * psw and gprs are stored on the stack
+		 */
+		if (addr == (addr_t) &dummy32->regs.psw.mask) {
+			/* Fake a 31 bit psw mask. */
+			tmp = (__u32)(regs->psw.mask >> 32);
+			tmp &= PSW32_MASK_USER | PSW32_MASK_RI;
+			tmp |= PSW32_USER_BITS;
+		} else if (addr == (addr_t) &dummy32->regs.psw.addr) {
+			/* Fake a 31 bit psw address. */
+			tmp = (__u32) regs->psw.addr |
+				(__u32)(regs->psw.mask & PSW_MASK_BA);
+		} else {
+			/* gpr 0-15 */
+			tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
+		}
+	} else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
+		/*
+		 * access registers are stored in the thread structure
+		 */
+		offset = addr - (addr_t) &dummy32->regs.acrs;
+		tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
+
+	} else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
+		/*
+		 * orig_gpr2 is stored on the kernel stack
+		 */
+		tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
+
+	} else if (addr < (addr_t) &dummy32->regs.fp_regs) {
+		/*
+		 * prevent reads of padding hole between
+		 * orig_gpr2 and fp_regs on s390.
+		 */
+		tmp = 0;
+
+	} else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
+		/*
+		 * floating point control reg. is in the thread structure
+		 */
+		tmp = child->thread.fp_regs.fpc;
+
+	} else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
+		/*
+		 * floating point regs. are either in child->thread.fp_regs
+		 * or the child->thread.vxrs array
+		 */
+		offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
+		if (child->thread.vxrs)
+			tmp = *(__u32 *)
+			       ((addr_t) child->thread.vxrs + 2*offset);
+		else
+			tmp = *(__u32 *)
+			       ((addr_t) &child->thread.fp_regs.fprs + offset);
+
+	} else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
+		/*
+		 * Handle access to the per_info structure.
+		 */
+		addr -= (addr_t) &dummy32->regs.per_info;
+		tmp = __peek_user_per_compat(child, addr);
+
+	} else
+		tmp = 0;
+
+	return tmp;
+}
+
+static int peek_user_compat(struct task_struct *child,
+			    addr_t addr, addr_t data)
+{
+	__u32 tmp;
+
+	if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
+		return -EIO;
+
+	tmp = __peek_user_compat(child, addr);
+	return put_user(tmp, (__u32 __user *) data);
+}
+
+/*
+ * Same as poke_user_per but for a 31 bit program.
+ */
+static inline void __poke_user_per_compat(struct task_struct *child,
+					  addr_t addr, __u32 data)
+{
+	struct compat_per_struct_kernel *dummy32 = NULL;
+
+	if (addr == (addr_t) &dummy32->cr9)
+		/* PER event mask of the user specified per set. */
+		child->thread.per_user.control =
+			data & (PER_EVENT_MASK | PER_CONTROL_MASK);
+	else if (addr == (addr_t) &dummy32->starting_addr)
+		/* Starting address of the user specified per set. */
+		child->thread.per_user.start = data;
+	else if (addr == (addr_t) &dummy32->ending_addr)
+		/* Ending address of the user specified per set. */
+		child->thread.per_user.end = data;
+}
+
+/*
+ * Same as poke_user but for a 31 bit program.
+ */
+static int __poke_user_compat(struct task_struct *child,
+			      addr_t addr, addr_t data)
+{
+	struct compat_user *dummy32 = NULL;
+	__u32 tmp = (__u32) data;
+	addr_t offset;
+
+	if (addr < (addr_t) &dummy32->regs.acrs) {
+		struct pt_regs *regs = task_pt_regs(child);
+		/*
+		 * psw, gprs, acrs and orig_gpr2 are stored on the stack
+		 */
+		if (addr == (addr_t) &dummy32->regs.psw.mask) {
+			__u32 mask = PSW32_MASK_USER;
+
+			mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
+			/* Build a 64 bit psw mask from 31 bit mask. */
+			if ((tmp ^ PSW32_USER_BITS) & ~mask)
+				/* Invalid psw mask. */
+				return -EINVAL;
+			if ((data & PSW32_MASK_ASC) == PSW32_ASC_HOME)
+				/* Invalid address-space-control bits */
+				return -EINVAL;
+			regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
+				(regs->psw.mask & PSW_MASK_BA) |
+				(__u64)(tmp & mask) << 32;
+		} else if (addr == (addr_t) &dummy32->regs.psw.addr) {
+			/* Build a 64 bit psw address from 31 bit address. */
+			regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
+			/* Transfer 31 bit amode bit to psw mask. */
+			regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
+				(__u64)(tmp & PSW32_ADDR_AMODE);
+		} else {
+			/* gpr 0-15 */
+			*(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
+		}
+	} else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
+		/*
+		 * access registers are stored in the thread structure
+		 */
+		offset = addr - (addr_t) &dummy32->regs.acrs;
+		*(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
+
+	} else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
+		/*
+		 * orig_gpr2 is stored on the kernel stack
+		 */
+		*(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
+
+	} else if (addr < (addr_t) &dummy32->regs.fp_regs) {
+		/*
+		 * prevent writess of padding hole between
+		 * orig_gpr2 and fp_regs on s390.
+		 */
+		return 0;
+
+	} else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
+		/*
+		 * floating point control reg. is in the thread structure
+		 */
+		if (test_fp_ctl(tmp))
+			return -EINVAL;
+		child->thread.fp_regs.fpc = data;
+
+	} else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
+		/*
+		 * floating point regs. are either in child->thread.fp_regs
+		 * or the child->thread.vxrs array
+		 */
+		offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
+		if (child->thread.vxrs)
+			*(__u32 *)((addr_t)
+				child->thread.vxrs + 2*offset) = tmp;
+		else
+			*(__u32 *)((addr_t)
+				&child->thread.fp_regs.fprs + offset) = tmp;
+
+	} else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
+		/*
+		 * Handle access to the per_info structure.
+		 */
+		addr -= (addr_t) &dummy32->regs.per_info;
+		__poke_user_per_compat(child, addr, data);
+	}
+
+	return 0;
+}
+
+static int poke_user_compat(struct task_struct *child,
+			    addr_t addr, addr_t data)
+{
+	if (!is_compat_task() || (addr & 3) ||
+	    addr > sizeof(struct compat_user) - 3)
+		return -EIO;
+
+	return __poke_user_compat(child, addr, data);
+}
+
+long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
+			compat_ulong_t caddr, compat_ulong_t cdata)
+{
+	unsigned long addr = caddr;
+	unsigned long data = cdata;
+	compat_ptrace_area parea;
+	int copied, ret;
+
+	switch (request) {
+	case PTRACE_PEEKUSR:
+		/* read the word at location addr in the USER area. */
+		return peek_user_compat(child, addr, data);
+
+	case PTRACE_POKEUSR:
+		/* write the word at location addr in the USER area */
+		return poke_user_compat(child, addr, data);
+
+	case PTRACE_PEEKUSR_AREA:
+	case PTRACE_POKEUSR_AREA:
+		if (copy_from_user(&parea, (void __force __user *) addr,
+							sizeof(parea)))
+			return -EFAULT;
+		addr = parea.kernel_addr;
+		data = parea.process_addr;
+		copied = 0;
+		while (copied < parea.len) {
+			if (request == PTRACE_PEEKUSR_AREA)
+				ret = peek_user_compat(child, addr, data);
+			else {
+				__u32 utmp;
+				if (get_user(utmp,
+					     (__u32 __force __user *) data))
+					return -EFAULT;
+				ret = poke_user_compat(child, addr, utmp);
+			}
+			if (ret)
+				return ret;
+			addr += sizeof(unsigned int);
+			data += sizeof(unsigned int);
+			copied += sizeof(unsigned int);
+		}
+		return 0;
+	case PTRACE_GET_LAST_BREAK:
+		put_user(task_thread_info(child)->last_break,
+			 (unsigned int __user *) data);
+		return 0;
+	}
+	return compat_ptrace_request(child, request, addr, data);
+}
+#endif
+
+asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
+{
+	long ret = 0;
+
+	/* Do the secure computing check first. */
+	if (secure_computing()) {
+		/* seccomp failures shouldn't expose any additional code. */
+		ret = -1;
+		goto out;
+	}
+
+	/*
+	 * The sysc_tracesys code in entry.S stored the system
+	 * call number to gprs[2].
+	 */
+	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
+	    (tracehook_report_syscall_entry(regs) ||
+	     regs->gprs[2] >= NR_syscalls)) {
+		/*
+		 * Tracing decided this syscall should not happen or the
+		 * debugger stored an invalid system call number. Skip
+		 * the system call and the system call restart handling.
+		 */
+		clear_pt_regs_flag(regs, PIF_SYSCALL);
+		ret = -1;
+	}
+
+	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
+		trace_sys_enter(regs, regs->gprs[2]);
+
+	audit_syscall_entry(regs->gprs[2], regs->orig_gpr2,
+			    regs->gprs[3], regs->gprs[4],
+			    regs->gprs[5]);
+out:
+	return ret ?: regs->gprs[2];
+}
+
+asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
+{
+	audit_syscall_exit(regs);
+
+	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
+		trace_sys_exit(regs, regs->gprs[2]);
+
+	if (test_thread_flag(TIF_SYSCALL_TRACE))
+		tracehook_report_syscall_exit(regs, 0);
+}
+
+/*
+ * user_regset definitions.
+ */
+
+static int s390_regs_get(struct task_struct *target,
+			 const struct user_regset *regset,
+			 unsigned int pos, unsigned int count,
+			 void *kbuf, void __user *ubuf)
+{
+	if (target == current)
+		save_access_regs(target->thread.acrs);
+
+	if (kbuf) {
+		unsigned long *k = kbuf;
+		while (count > 0) {
+			*k++ = __peek_user(target, pos);
+			count -= sizeof(*k);
+			pos += sizeof(*k);
+		}
+	} else {
+		unsigned long __user *u = ubuf;
+		while (count > 0) {
+			if (__put_user(__peek_user(target, pos), u++))
+				return -EFAULT;
+			count -= sizeof(*u);
+			pos += sizeof(*u);
+		}
+	}
+	return 0;
+}
+
+static int s390_regs_set(struct task_struct *target,
+			 const struct user_regset *regset,
+			 unsigned int pos, unsigned int count,
+			 const void *kbuf, const void __user *ubuf)
+{
+	int rc = 0;
+
+	if (target == current)
+		save_access_regs(target->thread.acrs);
+
+	if (kbuf) {
+		const unsigned long *k = kbuf;
+		while (count > 0 && !rc) {
+			rc = __poke_user(target, pos, *k++);
+			count -= sizeof(*k);
+			pos += sizeof(*k);
+		}
+	} else {
+		const unsigned long  __user *u = ubuf;
+		while (count > 0 && !rc) {
+			unsigned long word;
+			rc = __get_user(word, u++);
+			if (rc)
+				break;
+			rc = __poke_user(target, pos, word);
+			count -= sizeof(*u);
+			pos += sizeof(*u);
+		}
+	}
+
+	if (rc == 0 && target == current)
+		restore_access_regs(target->thread.acrs);
+
+	return rc;
+}
+
+static int s390_fpregs_get(struct task_struct *target,
+			   const struct user_regset *regset, unsigned int pos,
+			   unsigned int count, void *kbuf, void __user *ubuf)
+{
+	if (target == current) {
+		save_fp_ctl(&target->thread.fp_regs.fpc);
+		save_fp_regs(target->thread.fp_regs.fprs);
+	} else if (target->thread.vxrs) {
+		int i;
+
+		for (i = 0; i < __NUM_VXRS_LOW; i++)
+			target->thread.fp_regs.fprs[i] =
+				*(freg_t *)(target->thread.vxrs + i);
+	}
+	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+				   &target->thread.fp_regs, 0, -1);
+}
+
+static int s390_fpregs_set(struct task_struct *target,
+			   const struct user_regset *regset, unsigned int pos,
+			   unsigned int count, const void *kbuf,
+			   const void __user *ubuf)
+{
+	int rc = 0;
+
+	if (target == current) {
+		save_fp_ctl(&target->thread.fp_regs.fpc);
+		save_fp_regs(target->thread.fp_regs.fprs);
+	}
+
+	/* If setting FPC, must validate it first. */
+	if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
+		u32 ufpc[2] = { target->thread.fp_regs.fpc, 0 };
+		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
+					0, offsetof(s390_fp_regs, fprs));
+		if (rc)
+			return rc;
+		if (ufpc[1] != 0 || test_fp_ctl(ufpc[0]))
+			return -EINVAL;
+		target->thread.fp_regs.fpc = ufpc[0];
+	}
+
+	if (rc == 0 && count > 0)
+		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+					target->thread.fp_regs.fprs,
+					offsetof(s390_fp_regs, fprs), -1);
+
+	if (rc == 0) {
+		if (target == current) {
+			restore_fp_ctl(&target->thread.fp_regs.fpc);
+			restore_fp_regs(target->thread.fp_regs.fprs);
+		} else if (target->thread.vxrs) {
+			int i;
+
+			for (i = 0; i < __NUM_VXRS_LOW; i++)
+				*(freg_t *)(target->thread.vxrs + i) =
+					target->thread.fp_regs.fprs[i];
+		}
+	}
+
+	return rc;
+}
+
+static int s390_last_break_get(struct task_struct *target,
+			       const struct user_regset *regset,
+			       unsigned int pos, unsigned int count,
+			       void *kbuf, void __user *ubuf)
+{
+	if (count > 0) {
+		if (kbuf) {
+			unsigned long *k = kbuf;
+			*k = task_thread_info(target)->last_break;
+		} else {
+			unsigned long  __user *u = ubuf;
+			if (__put_user(task_thread_info(target)->last_break, u))
+				return -EFAULT;
+		}
+	}
+	return 0;
+}
+
+static int s390_last_break_set(struct task_struct *target,
+			       const struct user_regset *regset,
+			       unsigned int pos, unsigned int count,
+			       const void *kbuf, const void __user *ubuf)
+{
+	return 0;
+}
+
+static int s390_tdb_get(struct task_struct *target,
+			const struct user_regset *regset,
+			unsigned int pos, unsigned int count,
+			void *kbuf, void __user *ubuf)
+{
+	struct pt_regs *regs = task_pt_regs(target);
+	unsigned char *data;
+
+	if (!(regs->int_code & 0x200))
+		return -ENODATA;
+	data = target->thread.trap_tdb;
+	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, data, 0, 256);
+}
+
+static int s390_tdb_set(struct task_struct *target,
+			const struct user_regset *regset,
+			unsigned int pos, unsigned int count,
+			const void *kbuf, const void __user *ubuf)
+{
+	return 0;
+}
+
+static int s390_vxrs_low_get(struct task_struct *target,
+			     const struct user_regset *regset,
+			     unsigned int pos, unsigned int count,
+			     void *kbuf, void __user *ubuf)
+{
+	__u64 vxrs[__NUM_VXRS_LOW];
+	int i;
+
+	if (!MACHINE_HAS_VX)
+		return -ENODEV;
+	if (target->thread.vxrs) {
+		if (target == current)
+			save_vx_regs(target->thread.vxrs);
+		for (i = 0; i < __NUM_VXRS_LOW; i++)
+			vxrs[i] = *((__u64 *)(target->thread.vxrs + i) + 1);
+	} else
+		memset(vxrs, 0, sizeof(vxrs));
+	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
+}
+
+static int s390_vxrs_low_set(struct task_struct *target,
+			     const struct user_regset *regset,
+			     unsigned int pos, unsigned int count,
+			     const void *kbuf, const void __user *ubuf)
+{
+	__u64 vxrs[__NUM_VXRS_LOW];
+	int i, rc;
+
+	if (!MACHINE_HAS_VX)
+		return -ENODEV;
+	if (!target->thread.vxrs) {
+		rc = alloc_vector_registers(target);
+		if (rc)
+			return rc;
+	} else if (target == current)
+		save_vx_regs(target->thread.vxrs);
+
+	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
+	if (rc == 0) {
+		for (i = 0; i < __NUM_VXRS_LOW; i++)
+			*((__u64 *)(target->thread.vxrs + i) + 1) = vxrs[i];
+		if (target == current)
+			restore_vx_regs(target->thread.vxrs);
+	}
+
+	return rc;
+}
+
+static int s390_vxrs_high_get(struct task_struct *target,
+			      const struct user_regset *regset,
+			      unsigned int pos, unsigned int count,
+			      void *kbuf, void __user *ubuf)
+{
+	__vector128 vxrs[__NUM_VXRS_HIGH];
+
+	if (!MACHINE_HAS_VX)
+		return -ENODEV;
+	if (target->thread.vxrs) {
+		if (target == current)
+			save_vx_regs(target->thread.vxrs);
+		memcpy(vxrs, target->thread.vxrs + __NUM_VXRS_LOW,
+		       sizeof(vxrs));
+	} else
+		memset(vxrs, 0, sizeof(vxrs));
+	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
+}
+
+static int s390_vxrs_high_set(struct task_struct *target,
+			      const struct user_regset *regset,
+			      unsigned int pos, unsigned int count,
+			      const void *kbuf, const void __user *ubuf)
+{
+	int rc;
+
+	if (!MACHINE_HAS_VX)
+		return -ENODEV;
+	if (!target->thread.vxrs) {
+		rc = alloc_vector_registers(target);
+		if (rc)
+			return rc;
+	} else if (target == current)
+		save_vx_regs(target->thread.vxrs);
+
+	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				target->thread.vxrs + __NUM_VXRS_LOW, 0, -1);
+	if (rc == 0 && target == current)
+		restore_vx_regs(target->thread.vxrs);
+
+	return rc;
+}
+
+static int s390_system_call_get(struct task_struct *target,
+				const struct user_regset *regset,
+				unsigned int pos, unsigned int count,
+				void *kbuf, void __user *ubuf)
+{
+	unsigned int *data = &task_thread_info(target)->system_call;
+	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+				   data, 0, sizeof(unsigned int));
+}
+
+static int s390_system_call_set(struct task_struct *target,
+				const struct user_regset *regset,
+				unsigned int pos, unsigned int count,
+				const void *kbuf, const void __user *ubuf)
+{
+	unsigned int *data = &task_thread_info(target)->system_call;
+	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				  data, 0, sizeof(unsigned int));
+}
+
+static const struct user_regset s390_regsets[] = {
+	{
+		.core_note_type = NT_PRSTATUS,
+		.n = sizeof(s390_regs) / sizeof(long),
+		.size = sizeof(long),
+		.align = sizeof(long),
+		.get = s390_regs_get,
+		.set = s390_regs_set,
+	},
+	{
+		.core_note_type = NT_PRFPREG,
+		.n = sizeof(s390_fp_regs) / sizeof(long),
+		.size = sizeof(long),
+		.align = sizeof(long),
+		.get = s390_fpregs_get,
+		.set = s390_fpregs_set,
+	},
+	{
+		.core_note_type = NT_S390_SYSTEM_CALL,
+		.n = 1,
+		.size = sizeof(unsigned int),
+		.align = sizeof(unsigned int),
+		.get = s390_system_call_get,
+		.set = s390_system_call_set,
+	},
+	{
+		.core_note_type = NT_S390_LAST_BREAK,
+		.n = 1,
+		.size = sizeof(long),
+		.align = sizeof(long),
+		.get = s390_last_break_get,
+		.set = s390_last_break_set,
+	},
+	{
+		.core_note_type = NT_S390_TDB,
+		.n = 1,
+		.size = 256,
+		.align = 1,
+		.get = s390_tdb_get,
+		.set = s390_tdb_set,
+	},
+	{
+		.core_note_type = NT_S390_VXRS_LOW,
+		.n = __NUM_VXRS_LOW,
+		.size = sizeof(__u64),
+		.align = sizeof(__u64),
+		.get = s390_vxrs_low_get,
+		.set = s390_vxrs_low_set,
+	},
+	{
+		.core_note_type = NT_S390_VXRS_HIGH,
+		.n = __NUM_VXRS_HIGH,
+		.size = sizeof(__vector128),
+		.align = sizeof(__vector128),
+		.get = s390_vxrs_high_get,
+		.set = s390_vxrs_high_set,
+	},
+};
+
+static const struct user_regset_view user_s390_view = {
+	.name = UTS_MACHINE,
+	.e_machine = EM_S390,
+	.regsets = s390_regsets,
+	.n = ARRAY_SIZE(s390_regsets)
+};
+
+#ifdef CONFIG_COMPAT
+static int s390_compat_regs_get(struct task_struct *target,
+				const struct user_regset *regset,
+				unsigned int pos, unsigned int count,
+				void *kbuf, void __user *ubuf)
+{
+	if (target == current)
+		save_access_regs(target->thread.acrs);
+
+	if (kbuf) {
+		compat_ulong_t *k = kbuf;
+		while (count > 0) {
+			*k++ = __peek_user_compat(target, pos);
+			count -= sizeof(*k);
+			pos += sizeof(*k);
+		}
+	} else {
+		compat_ulong_t __user *u = ubuf;
+		while (count > 0) {
+			if (__put_user(__peek_user_compat(target, pos), u++))
+				return -EFAULT;
+			count -= sizeof(*u);
+			pos += sizeof(*u);
+		}
+	}
+	return 0;
+}
+
+static int s390_compat_regs_set(struct task_struct *target,
+				const struct user_regset *regset,
+				unsigned int pos, unsigned int count,
+				const void *kbuf, const void __user *ubuf)
+{
+	int rc = 0;
+
+	if (target == current)
+		save_access_regs(target->thread.acrs);
+
+	if (kbuf) {
+		const compat_ulong_t *k = kbuf;
+		while (count > 0 && !rc) {
+			rc = __poke_user_compat(target, pos, *k++);
+			count -= sizeof(*k);
+			pos += sizeof(*k);
+		}
+	} else {
+		const compat_ulong_t  __user *u = ubuf;
+		while (count > 0 && !rc) {
+			compat_ulong_t word;
+			rc = __get_user(word, u++);
+			if (rc)
+				break;
+			rc = __poke_user_compat(target, pos, word);
+			count -= sizeof(*u);
+			pos += sizeof(*u);
+		}
+	}
+
+	if (rc == 0 && target == current)
+		restore_access_regs(target->thread.acrs);
+
+	return rc;
+}
+
+static int s390_compat_regs_high_get(struct task_struct *target,
+				     const struct user_regset *regset,
+				     unsigned int pos, unsigned int count,
+				     void *kbuf, void __user *ubuf)
+{
+	compat_ulong_t *gprs_high;
+
+	gprs_high = (compat_ulong_t *)
+		&task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
+	if (kbuf) {
+		compat_ulong_t *k = kbuf;
+		while (count > 0) {
+			*k++ = *gprs_high;
+			gprs_high += 2;
+			count -= sizeof(*k);
+		}
+	} else {
+		compat_ulong_t __user *u = ubuf;
+		while (count > 0) {
+			if (__put_user(*gprs_high, u++))
+				return -EFAULT;
+			gprs_high += 2;
+			count -= sizeof(*u);
+		}
+	}
+	return 0;
+}
+
+static int s390_compat_regs_high_set(struct task_struct *target,
+				     const struct user_regset *regset,
+				     unsigned int pos, unsigned int count,
+				     const void *kbuf, const void __user *ubuf)
+{
+	compat_ulong_t *gprs_high;
+	int rc = 0;
+
+	gprs_high = (compat_ulong_t *)
+		&task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
+	if (kbuf) {
+		const compat_ulong_t *k = kbuf;
+		while (count > 0) {
+			*gprs_high = *k++;
+			*gprs_high += 2;
+			count -= sizeof(*k);
+		}
+	} else {
+		const compat_ulong_t  __user *u = ubuf;
+		while (count > 0 && !rc) {
+			unsigned long word;
+			rc = __get_user(word, u++);
+			if (rc)
+				break;
+			*gprs_high = word;
+			*gprs_high += 2;
+			count -= sizeof(*u);
+		}
+	}
+
+	return rc;
+}
+
+static int s390_compat_last_break_get(struct task_struct *target,
+				      const struct user_regset *regset,
+				      unsigned int pos, unsigned int count,
+				      void *kbuf, void __user *ubuf)
+{
+	compat_ulong_t last_break;
+
+	if (count > 0) {
+		last_break = task_thread_info(target)->last_break;
+		if (kbuf) {
+			unsigned long *k = kbuf;
+			*k = last_break;
+		} else {
+			unsigned long  __user *u = ubuf;
+			if (__put_user(last_break, u))
+				return -EFAULT;
+		}
+	}
+	return 0;
+}
+
+static int s390_compat_last_break_set(struct task_struct *target,
+				      const struct user_regset *regset,
+				      unsigned int pos, unsigned int count,
+				      const void *kbuf, const void __user *ubuf)
+{
+	return 0;
+}
+
+static const struct user_regset s390_compat_regsets[] = {
+	{
+		.core_note_type = NT_PRSTATUS,
+		.n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
+		.size = sizeof(compat_long_t),
+		.align = sizeof(compat_long_t),
+		.get = s390_compat_regs_get,
+		.set = s390_compat_regs_set,
+	},
+	{
+		.core_note_type = NT_PRFPREG,
+		.n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
+		.size = sizeof(compat_long_t),
+		.align = sizeof(compat_long_t),
+		.get = s390_fpregs_get,
+		.set = s390_fpregs_set,
+	},
+	{
+		.core_note_type = NT_S390_SYSTEM_CALL,
+		.n = 1,
+		.size = sizeof(compat_uint_t),
+		.align = sizeof(compat_uint_t),
+		.get = s390_system_call_get,
+		.set = s390_system_call_set,
+	},
+	{
+		.core_note_type = NT_S390_LAST_BREAK,
+		.n = 1,
+		.size = sizeof(long),
+		.align = sizeof(long),
+		.get = s390_compat_last_break_get,
+		.set = s390_compat_last_break_set,
+	},
+	{
+		.core_note_type = NT_S390_TDB,
+		.n = 1,
+		.size = 256,
+		.align = 1,
+		.get = s390_tdb_get,
+		.set = s390_tdb_set,
+	},
+	{
+		.core_note_type = NT_S390_VXRS_LOW,
+		.n = __NUM_VXRS_LOW,
+		.size = sizeof(__u64),
+		.align = sizeof(__u64),
+		.get = s390_vxrs_low_get,
+		.set = s390_vxrs_low_set,
+	},
+	{
+		.core_note_type = NT_S390_VXRS_HIGH,
+		.n = __NUM_VXRS_HIGH,
+		.size = sizeof(__vector128),
+		.align = sizeof(__vector128),
+		.get = s390_vxrs_high_get,
+		.set = s390_vxrs_high_set,
+	},
+	{
+		.core_note_type = NT_S390_HIGH_GPRS,
+		.n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
+		.size = sizeof(compat_long_t),
+		.align = sizeof(compat_long_t),
+		.get = s390_compat_regs_high_get,
+		.set = s390_compat_regs_high_set,
+	},
+};
+
+static const struct user_regset_view user_s390_compat_view = {
+	.name = "s390",
+	.e_machine = EM_S390,
+	.regsets = s390_compat_regsets,
+	.n = ARRAY_SIZE(s390_compat_regsets)
+};
+#endif
+
+const struct user_regset_view *task_user_regset_view(struct task_struct *task)
+{
+#ifdef CONFIG_COMPAT
+	if (test_tsk_thread_flag(task, TIF_31BIT))
+		return &user_s390_compat_view;
+#endif
+	return &user_s390_view;
+}
+
+static const char *gpr_names[NUM_GPRS] = {
+	"r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
+	"r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
+};
+
+unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
+{
+	if (offset >= NUM_GPRS)
+		return 0;
+	return regs->gprs[offset];
+}
+
+int regs_query_register_offset(const char *name)
+{
+	unsigned long offset;
+
+	if (!name || *name != 'r')
+		return -EINVAL;
+	if (kstrtoul(name + 1, 10, &offset))
+		return -EINVAL;
+	if (offset >= NUM_GPRS)
+		return -EINVAL;
+	return offset;
+}
+
+const char *regs_query_register_name(unsigned int offset)
+{
+	if (offset >= NUM_GPRS)
+		return NULL;
+	return gpr_names[offset];
+}
+
+static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
+{
+	unsigned long ksp = kernel_stack_pointer(regs);
+
+	return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
+}
+
+/**
+ * regs_get_kernel_stack_nth() - get Nth entry of the stack
+ * @regs:pt_regs which contains kernel stack pointer.
+ * @n:stack entry number.
+ *
+ * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
+ * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
+ * this returns 0.
+ */
+unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
+{
+	unsigned long addr;
+
+	addr = kernel_stack_pointer(regs) + n * sizeof(long);
+	if (!regs_within_kernel_stack(regs, addr))
+		return 0;
+	return *(unsigned long *)addr;
+}