Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / arch / s390 / kernel / ptrace.c
diff --git a/kernel/arch/s390/kernel/ptrace.c b/kernel/arch/s390/kernel/ptrace.c
new file mode 100644 (file)
index 0000000..d363c9c
--- /dev/null
@@ -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;
+}