Merge to Fedora kernel-2.6.18-1.2224_FC5 patched with stable patch-2.6.18.1-vs2.0...
[linux-2.6.git] / arch / s390 / kernel / ptrace.c
index 5a3bb17..74c3133 100644 (file)
@@ -29,6 +29,8 @@
 #include <linux/smp_lock.h>
 #include <linux/errno.h>
 #include <linux/ptrace.h>
+#include <linux/tracehook.h>
+#include <linux/module.h>
 #include <linux/user.h>
 #include <linux/security.h>
 #include <linux/audit.h>
@@ -41,6 +43,7 @@
 #include <asm/system.h>
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
+#include <asm/elf.h>
 
 #ifdef CONFIG_COMPAT
 #include "compat_ptrace.h"
@@ -84,34 +87,601 @@ FixPerRegisters(struct task_struct *task)
                per_info->control_regs.bits.storage_alt_space_ctl = 1;
        else
                per_info->control_regs.bits.storage_alt_space_ctl = 0;
+
+       if (task == current)
+               /*
+                * These registers are loaded in __switch_to on
+                * context switch.  We must load them now if
+                * touching the current thread.
+                */
+               __ctl_load(per_info->control_regs.words.cr, 9, 11);
 }
 
 void
-set_single_step(struct task_struct *task)
+tracehook_enable_single_step(struct task_struct *task)
 {
        task->thread.per_info.single_step = 1;
        FixPerRegisters(task);
 }
 
 void
-clear_single_step(struct task_struct *task)
+tracehook_disable_single_step(struct task_struct *task)
 {
        task->thread.per_info.single_step = 0;
        FixPerRegisters(task);
+       clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
+}
+
+int
+tracehook_single_step_enabled(struct task_struct *task)
+{
+       return task->thread.per_info.single_step;
+}
+
+
+static int
+genregs_get(struct task_struct *target,
+           const struct utrace_regset *regset,
+           unsigned int pos, unsigned int count,
+           void *kbuf, void __user *ubuf)
+{
+       struct pt_regs *regs = task_pt_regs(target);
+       unsigned long pswmask;
+       int ret;
+
+       /* Remove per bit from user psw. */
+       pswmask = regs->psw.mask & ~PSW_MASK_PER;
+       ret = utrace_regset_copyout(&pos, &count, &kbuf, &ubuf,
+                                   &pswmask, PT_PSWMASK, PT_PSWADDR);
+
+       /* The rest of the PSW and the GPRs are directly on the stack. */
+       if (ret == 0)
+               ret = utrace_regset_copyout(&pos, &count, &kbuf, &ubuf,
+                                           &regs->psw.addr, PT_PSWADDR,
+                                           PT_ACR0);
+
+       /* The ACRs are kept in the thread_struct.  */
+       if (ret == 0 && count > 0 && pos < PT_ORIGGPR2) {
+               if (target == current)
+                       save_access_regs(target->thread.acrs);
+
+               ret = utrace_regset_copyout(&pos, &count, &kbuf, &ubuf,
+                                           target->thread.acrs,
+                                           PT_ACR0, PT_ORIGGPR2);
+       }
+
+       /* Finally, the ORIG_GPR2 value.  */
+       if (ret == 0)
+               ret = utrace_regset_copyout(&pos, &count, &kbuf, &ubuf,
+                                           &regs->orig_gpr2, PT_ORIGGPR2, -1);
+
+       return ret;
+}
+
+static int
+genregs_set(struct task_struct *target,
+           const struct utrace_regset *regset,
+           unsigned int pos, unsigned int count,
+           const void *kbuf, const void __user *ubuf)
+{
+       struct pt_regs *regs = task_pt_regs(target);
+       int ret = 0;
+
+       /* Check for an invalid PSW mask.  */
+       if (count > 0 && pos == PT_PSWMASK) {
+               unsigned long pswmask = regs->psw.mask;
+               ret = utrace_regset_copyin(&pos, &count, &kbuf, &ubuf,
+                                          &pswmask, PT_PSWMASK, PT_PSWADDR);
+               if (pswmask != PSW_MASK_MERGE(PSW_USER_BITS, pswmask)
+#ifdef CONFIG_COMPAT
+                   && pswmask != PSW_MASK_MERGE(PSW_USER32_BITS, pswmask)
+#endif
+                       )
+                       /* Invalid psw mask. */
+                       return -EINVAL;
+               regs->psw.mask = pswmask;
+               FixPerRegisters(target);
+       }
+
+       /* The rest of the PSW and the GPRs are directly on the stack. */
+       if (ret == 0) {
+               ret = utrace_regset_copyin(&pos, &count, &kbuf, &ubuf,
+                                          &regs->psw.addr, PT_PSWADDR,
+                                          PT_ACR0);
+#ifndef CONFIG_64BIT
+               /* I'd like to reject addresses without the
+                  high order bit but older gdb's rely on it */
+               regs->psw.addr |= PSW_ADDR_AMODE;
+#endif
+       }
+
+       /* The ACRs are kept in the thread_struct.  */
+       if (ret == 0 && count > 0 && pos < PT_ORIGGPR2) {
+               if (target == current
+                   && (pos != PT_ACR0 || count < sizeof(target->thread.acrs)))
+                       save_access_regs(target->thread.acrs);
+
+               ret = utrace_regset_copyin(&pos, &count, &kbuf, &ubuf,
+                                          target->thread.acrs,
+                                          PT_ACR0, PT_ORIGGPR2);
+               if (ret == 0 && target == current)
+                       restore_access_regs(target->thread.acrs);
+       }
+
+       /* Finally, the ORIG_GPR2 value.  */
+       if (ret == 0)
+               ret = utrace_regset_copyin(&pos, &count, &kbuf, &ubuf,
+                                          &regs->orig_gpr2, PT_ORIGGPR2, -1);
+
+       return ret;
+}
+
+static int
+fpregs_get(struct task_struct *target,
+          const struct utrace_regset *regset,
+          unsigned int pos, unsigned int count,
+          void *kbuf, void __user *ubuf)
+{
+       if (target == current)
+               save_fp_regs(&target->thread.fp_regs);
+
+       return utrace_regset_copyout(&pos, &count, &kbuf, &ubuf,
+                                    &target->thread.fp_regs, 0, -1);
+}
+
+static int
+fpregs_set(struct task_struct *target,
+           const struct utrace_regset *regset,
+           unsigned int pos, unsigned int count,
+           const void *kbuf, const void __user *ubuf)
+{
+       int ret = 0;
+
+       if (target == current && (pos != 0 || count != sizeof(s390_fp_regs)))
+               save_fp_regs(&target->thread.fp_regs);
+
+       /* If setting FPC, must validate it first. */
+       if (count > 0 && pos == 0) {
+               unsigned long fpc;
+               ret = utrace_regset_copyin(&pos, &count, &kbuf, &ubuf,
+                                          &fpc, 0, sizeof(fpc));
+               if (ret)
+                       return ret;
+
+               if ((fpc & ~((unsigned long) FPC_VALID_MASK
+                            << (BITS_PER_LONG - 32))) != 0)
+                       return -EINVAL;
+
+               memcpy(&target->thread.fp_regs, &fpc, sizeof(fpc));
+       }
+
+       if (ret == 0)
+               ret = utrace_regset_copyin(&pos, &count, &kbuf, &ubuf,
+                                          &target->thread.fp_regs, 0, -1);
+
+       if (ret == 0 && target == current)
+               restore_fp_regs(&target->thread.fp_regs);
+
+       return ret;
+}
+
+static int
+per_info_get(struct task_struct *target,
+            const struct utrace_regset *regset,
+            unsigned int pos, unsigned int count,
+            void *kbuf, void __user *ubuf)
+{
+       return utrace_regset_copyout(&pos, &count, &kbuf, &ubuf,
+                                    &target->thread.per_info, 0, -1);
+}
+
+static int
+per_info_set(struct task_struct *target,
+            const struct utrace_regset *regset,
+            unsigned int pos, unsigned int count,
+            const void *kbuf, const void __user *ubuf)
+{
+       int ret = utrace_regset_copyin(&pos, &count, &kbuf, &ubuf,
+                                      &target->thread.per_info, 0, -1);
+
+       FixPerRegisters(target);
+
+       return ret;
 }
 
+
 /*
- * Called by kernel/ptrace.c when detaching..
- *
- * Make sure single step bits etc are not set.
+ * These are our native regset flavors.
  */
-void
-ptrace_disable(struct task_struct *child)
+static const struct utrace_regset native_regsets[] = {
+       {
+               .size = sizeof(long), .align = sizeof(long),
+               .n = sizeof(s390_regs) / sizeof(long),
+               .get = genregs_get, .set = genregs_set
+       },
+       {
+               .size = sizeof(long), .align = sizeof(long),
+               .n = sizeof(s390_fp_regs) / sizeof(long),
+               .get = fpregs_get, .set = fpregs_set
+       },
+       {
+               .size = sizeof(long), .align = sizeof(long),
+               .n = sizeof(per_struct) / sizeof(long),
+               .get = per_info_get, .set = per_info_set
+       },
+};
+
+const struct utrace_regset_view utrace_s390_native_view = {
+       .name = UTS_MACHINE, .e_machine = ELF_ARCH,
+       .regsets = native_regsets,
+       .n = sizeof native_regsets / sizeof native_regsets[0],
+};
+EXPORT_SYMBOL_GPL(utrace_s390_native_view);
+
+
+#ifdef CONFIG_COMPAT
+static int
+s390_genregs_get(struct task_struct *target,
+                const struct utrace_regset *regset,
+                unsigned int pos, unsigned int count,
+                void *kbuf, void __user *ubuf)
 {
-       /* make sure the single step bit is not set. */
-       clear_single_step(child);
+       struct pt_regs *regs = task_pt_regs(target);
+       int ret = 0;
+
+       /* Fake a 31 bit psw mask. */
+       if (count > 0 && pos == PT_PSWMASK / 2) {
+               u32 pswmask = PSW32_MASK_MERGE(PSW32_USER_BITS,
+                                              (u32) (regs->psw.mask >> 32));
+               ret = utrace_regset_copyout(&pos, &count, &kbuf, &ubuf,
+                                           &pswmask, PT_PSWMASK / 2,
+                                           PT_PSWADDR / 2);
+       }
+
+       /* Fake a 31 bit psw address. */
+       if (ret == 0 && count > 0 && pos == PT_PSWADDR / 2) {
+               u32 pswaddr = (u32) regs->psw.addr | PSW32_ADDR_AMODE31;
+               ret = utrace_regset_copyout(&pos, &count, &kbuf, &ubuf,
+                                           &pswaddr, PT_PSWADDR / 2,
+                                           PT_GPR0 / 2);
+       }
+
+       /* The GPRs are directly on the stack.  Just truncate them.  */
+       while (ret == 0 && count > 0 && pos < PT_ACR0 / 2) {
+               u32 value = regs->gprs[(pos - PT_GPR0 / 2) / sizeof(u32)];
+               if (kbuf) {
+                       *(u32 *) kbuf = value;
+                       kbuf += sizeof(u32);
+               }
+               else if (put_user(value, (u32 __user *) ubuf))
+                       ret = -EFAULT;
+               else
+                       ubuf += sizeof(u32);
+               pos += sizeof(u32);
+               count -= sizeof(u32);
+       }
+
+       /* The ACRs are kept in the thread_struct.  */
+       if (ret == 0 && count > 0 && pos < PT_ACR0 / 2 + NUM_ACRS * ACR_SIZE) {
+               if (target == current)
+                       save_access_regs(target->thread.acrs);
+
+               ret = utrace_regset_copyout(&pos, &count, &kbuf, &ubuf,
+                                           target->thread.acrs,
+                                           PT_ACR0 / 2,
+                                           PT_ACR0 / 2 + NUM_ACRS * ACR_SIZE);
+       }
+
+       /* Finally, the ORIG_GPR2 value.  */
+       if (count > 0) {
+               if (kbuf)
+                       *(u32 *) kbuf = regs->orig_gpr2;
+               else if (put_user((u32) regs->orig_gpr2,
+                                 (u32 __user *) ubuf))
+                       return -EFAULT;
+       }
+
+       return 0;
 }
 
+static int
+s390_genregs_set(struct task_struct *target,
+                const struct utrace_regset *regset,
+                unsigned int pos, unsigned int count,
+                const void *kbuf, const void __user *ubuf)
+{
+       struct pt_regs *regs = task_pt_regs(target);
+       int ret = 0;
+
+       /* Check for an invalid PSW mask.  */
+       if (count > 0 && pos == PT_PSWMASK / 2) {
+               u32 pswmask;
+               ret = utrace_regset_copyin(&pos, &count, &kbuf, &ubuf,
+                                          &pswmask, PT_PSWMASK / 2,
+                                          PT_PSWADDR / 2);
+               if (ret)
+                       return ret;
+
+               if (pswmask != PSW_MASK_MERGE(PSW_USER32_BITS, pswmask))
+                       /* Invalid psw mask. */
+                       return -EINVAL;
+
+               /* Build a 64 bit psw mask from 31 bit mask. */
+               regs->psw.mask = PSW_MASK_MERGE(PSW_USER32_BITS,
+                                               (u64) pswmask << 32);
+               FixPerRegisters(target);
+       }
+
+       /* Build a 64 bit psw address from 31 bit address. */
+       if (count > 0 && pos == PT_PSWADDR / 2) {
+               u32 pswaddr;
+               ret = utrace_regset_copyin(&pos, &count, &kbuf, &ubuf,
+                                          &pswaddr, PT_PSWADDR / 2,
+                                          PT_GPR0 / 2);
+               if (ret == 0)
+                       /* Build a 64 bit psw mask from 31 bit mask. */
+                       regs->psw.addr = pswaddr & PSW32_ADDR_INSN;
+       }
+
+       /* The GPRs are directly onto the stack. */
+       while (ret == 0 && count > 0 && pos < PT_ACR0 / 2) {
+               u32 value;
+
+               if (kbuf) {
+                       value = *(const u32 *) kbuf;
+                       kbuf += sizeof(u32);
+               }
+               else if (get_user(value, (const u32 __user *) ubuf))
+                       return -EFAULT;
+               else
+                       ubuf += sizeof(u32);
+               pos += sizeof(u32);
+               count -= sizeof(u32);
+
+               regs->gprs[(pos - PT_GPR0 / 2) / sizeof(u32)] = value;
+       }
+
+       /* The ACRs are kept in the thread_struct.  */
+       if (count > 0 && pos < PT_ORIGGPR2 / 2) {
+               if (target == current
+                   && (pos != PT_ACR0 / 2
+                       || count < sizeof(target->thread.acrs)))
+                       save_access_regs(target->thread.acrs);
+
+               ret = utrace_regset_copyin(&pos, &count, &kbuf, &ubuf,
+                                          target->thread.acrs,
+                                          PT_ACR0 / 2,
+                                          PT_ACR0 / 2 + NUM_ACRS * ACR_SIZE);
+
+               if (ret == 0 && target == current)
+                       restore_access_regs(target->thread.acrs);
+       }
+
+       /* Finally, the ORIG_GPR2 value.  */
+       if (ret == 0 && count > 0) {
+               u32 value;
+               if (kbuf)
+                       value = *(const u32 *) kbuf;
+               else if (get_user(value, (const u32 __user *) ubuf))
+                       return -EFAULT;
+               regs->orig_gpr2 = value;
+       }
+
+       return ret;
+}
+
+
+/*
+ * This is magic. See per_struct and per_struct32.
+ * By incident the offsets in per_struct are exactly
+ * twice the offsets in per_struct32 for all fields.
+ * The 8 byte fields need special handling though,
+ * because the second half (bytes 4-7) is needed and
+ * not the first half.
+ */
+static unsigned int
+offset_from_per32(unsigned int offset)
+{
+       BUILD_BUG_ON(offsetof(per_struct32, control_regs) != 0);
+       if (offset - offsetof(per_struct32, control_regs) < 3*sizeof(u32)
+           || (offset >= offsetof(per_struct32, starting_addr) &&
+               offset <= offsetof(per_struct32, ending_addr))
+           || offset == offsetof(per_struct32, lowcore.words.address))
+               offset = offset*2 + 4;
+       else
+               offset = offset*2;
+       return offset;
+}
+
+static int
+s390_per_info_get(struct task_struct *target,
+                 const struct utrace_regset *regset,
+                 unsigned int pos, unsigned int count,
+                 void *kbuf, void __user *ubuf)
+{
+       while (count > 0) {
+               u32 val = *(u32 *) ((char *) &target->thread.per_info
+                                   + offset_from_per32 (pos));
+               if (kbuf) {
+                       *(u32 *) kbuf = val;
+                       kbuf += sizeof(u32);
+               }
+               else if (put_user(val, (u32 __user *) ubuf))
+                       return -EFAULT;
+               else
+                       ubuf += sizeof(u32);
+               pos += sizeof(u32);
+               count -= sizeof(u32);
+       }
+       return 0;
+}
+
+static int
+s390_per_info_set(struct task_struct *target,
+                 const struct utrace_regset *regset,
+                 unsigned int pos, unsigned int count,
+                 const void *kbuf, const void __user *ubuf)
+{
+       while (count > 0) {
+               u32 val;
+
+               if (kbuf) {
+                       val = *(const u32 *) kbuf;
+                       kbuf += sizeof(u32);
+               }
+               else if (get_user(val, (const u32 __user *) ubuf))
+                       return -EFAULT;
+               else
+                       ubuf += sizeof(u32);
+               pos += sizeof(u32);
+               count -= sizeof(u32);
+
+               *(u32 *) ((char *) &target->thread.per_info
+                         + offset_from_per32 (pos)) = val;
+       }
+       return 0;
+}
+
+
+static const struct utrace_regset s390_compat_regsets[] = {
+       {
+               .size = sizeof(u32), .align = sizeof(u32),
+               .n = sizeof(s390_regs) / sizeof(long),
+               .get = s390_genregs_get, .set = s390_genregs_set
+       },
+       {
+               .size = sizeof(u32), .align = sizeof(u32),
+               .n = sizeof(s390_fp_regs) / sizeof(u32),
+               .get = fpregs_get, .set = fpregs_set
+       },
+       {
+               .size = sizeof(u32), .align = sizeof(u32),
+               .n = sizeof(per_struct) / sizeof(u32),
+               .get = s390_per_info_get, .set = s390_per_info_set
+       },
+};
+
+const struct utrace_regset_view utrace_s390_compat_view = {
+       .name = "s390", .e_machine = EM_S390,
+       .regsets = s390_compat_regsets,
+       .n = sizeof s390_compat_regsets / sizeof s390_compat_regsets[0],
+};
+EXPORT_SYMBOL_GPL(utrace_s390_compat_view);
+#endif /* CONFIG_COMPAT */
+
+
+#ifdef CONFIG_PTRACE
+static const struct ptrace_layout_segment s390_uarea[] = {
+       {PT_PSWMASK, PT_FPC, 0, 0},
+       {PT_FPC, PT_CR_9, 1, 0},
+       {PT_CR_9, PT_IEEE_IP, 2, 0},
+       {PT_IEEE_IP, sizeof(struct user), -1, -1},
+       {0, 0, -1, 0}
+};
+
+fastcall int arch_ptrace(long *request, struct task_struct *child,
+                        struct utrace_attached_engine *engine,
+                        unsigned long addr, unsigned long data, long *val)
+{
+       ptrace_area parea;
+       unsigned long tmp;
+       int copied;
+
+       switch (*request) {
+       case PTRACE_PEEKUSR:
+               return ptrace_peekusr(child, engine, s390_uarea, addr, data);
+       case PTRACE_POKEUSR:
+               return ptrace_pokeusr(child, engine, s390_uarea, addr, data);
+
+       case PTRACE_PEEKUSR_AREA:
+       case PTRACE_POKEUSR_AREA:
+               if (copy_from_user(&parea, (ptrace_area __user *) addr,
+                                  sizeof(parea)))
+                       return -EFAULT;
+               if ((parea.kernel_addr | parea.len) & (sizeof(data) - 1))
+                       return -EIO;
+               return ptrace_layout_access(child, engine,
+                                           utrace_native_view(current),
+                                           s390_uarea,
+                                           parea.kernel_addr, parea.len,
+                                           (void __user *) parea.process_addr,
+                                           NULL,
+                                           *request == PTRACE_POKEUSR_AREA);
+
+       case PTRACE_PEEKTEXT:
+       case PTRACE_PEEKDATA:
+               /* Remove high order bit from address (only for 31 bit). */
+               addr &= PSW_ADDR_INSN;
+               /* read word at location addr. */
+               copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
+               if (copied != sizeof(tmp))
+                       return -EIO;
+               return put_user(tmp, (unsigned long __user *) data);
+
+       case PTRACE_POKETEXT:
+       case PTRACE_POKEDATA:
+               /* Remove high order bit from address (only for 31 bit). */
+               addr &= PSW_ADDR_INSN;
+               /* write the word at location addr. */
+               copied = access_process_vm(child, addr, &data, sizeof(data),1);
+               if (copied != sizeof(data))
+                       return -EIO;
+               return 0;
+       }
+
+       return -ENOSYS;
+}
+
+#ifdef CONFIG_COMPAT
+static const struct ptrace_layout_segment s390_compat_uarea[] = {
+       {PT_PSWMASK / 2, PT_FPC / 2, 0, 0},
+       {PT_FPC / 2, PT_CR_9 / 2, 1, 0},
+       {PT_CR_9 / 2, PT_IEEE_IP / 2, 2, 0},
+       {PT_IEEE_IP / 2, sizeof(struct user32), -1, -1},
+       {0, 0, -1, 0}
+};
+
+fastcall int arch_compat_ptrace(compat_long_t *request,
+                               struct task_struct *child,
+                               struct utrace_attached_engine *engine,
+                               compat_ulong_t addr, compat_ulong_t data,
+                               compat_long_t *val)
+{
+       ptrace_area_emu31 parea;
+
+       switch (*request) {
+       case PTRACE_PEEKUSR:
+               return ptrace_compat_peekusr(child, engine, s390_compat_uarea,
+                                            addr, data);
+       case PTRACE_POKEUSR:
+               return ptrace_compat_pokeusr(child, engine, s390_compat_uarea,
+                                            addr, data);
+       case PTRACE_PEEKUSR_AREA:
+       case PTRACE_POKEUSR_AREA:
+               if (copy_from_user(&parea, ((ptrace_area_emu31 __user *)
+                                           (unsigned long) addr),
+                                  sizeof(parea)))
+                       return -EFAULT;
+               if ((parea.kernel_addr | parea.len) & (sizeof(data) - 1))
+                       return -EIO;
+               return ptrace_layout_access(child, engine,
+                                           utrace_native_view(current),
+                                           s390_compat_uarea,
+                                           parea.kernel_addr, parea.len,
+                                           (void __user *)
+                                           (unsigned long) parea.process_addr,
+                                           NULL,
+                                           *request == PTRACE_POKEUSR_AREA);
+       }
+
+       return -ENOSYS;
+}
+#endif /* CONFIG_COMPAT */
+#endif /* CONFIG_PTRACE */
+
+
+#if 0                          /* XXX */
+
 #ifndef CONFIG_64BIT
 # define __ADDR_MASK 3
 #else
@@ -593,6 +1163,7 @@ do_ptrace_emu31(struct task_struct *child, long request, long addr, long data)
                        copied += sizeof(unsigned int);
                }
                return 0;
+#if 0                          /* XXX */
        case PTRACE_GETEVENTMSG:
                return put_user((__u32) child->ptrace_message,
                                (unsigned int __user *) data);
@@ -606,6 +1177,7 @@ do_ptrace_emu31(struct task_struct *child, long request, long addr, long data)
                        return -EINVAL;
                return copy_siginfo_from_user32(child->last_siginfo,
                                                (compat_siginfo_t __user *) data);
+#endif
        }
        return ptrace_request(child, request, addr, data);
 }
@@ -656,7 +1228,7 @@ do_ptrace(struct task_struct *child, long request, long addr, long data)
                        clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
                child->exit_code = data;
                /* make sure the single step bit is not set. */
-               clear_single_step(child);
+               tracehook_disable_single_step(child);
                wake_up_process(child);
                return 0;
 
@@ -670,7 +1242,7 @@ do_ptrace(struct task_struct *child, long request, long addr, long data)
                        return 0;
                child->exit_code = SIGKILL;
                /* make sure the single step bit is not set. */
-               clear_single_step(child);
+               tracehook_disable_single_step(child);
                wake_up_process(child);
                return 0;
 
@@ -683,7 +1255,7 @@ do_ptrace(struct task_struct *child, long request, long addr, long data)
                if (data)
                        set_tsk_thread_flag(child, TIF_SINGLE_STEP);
                else
-                       set_single_step(child);
+                       tracehook_enable_single_step(child);
                /* give it a chance to run. */
                wake_up_process(child);
                return 0;
@@ -704,37 +1276,9 @@ do_ptrace(struct task_struct *child, long request, long addr, long data)
        /* Not reached.  */
        return -EIO;
 }
+#endif
 
-asmlinkage long
-sys_ptrace(long request, long pid, long addr, long data)
-{
-       struct task_struct *child;
-       int ret;
-
-       lock_kernel();
-       if (request == PTRACE_TRACEME) {
-                ret = ptrace_traceme();
-                goto out;
-       }
-
-       child = ptrace_get_task_struct(pid);
-       if (IS_ERR(child)) {
-               ret = PTR_ERR(child);
-               goto out;
-       }
-
-       if (!vx_check(vx_task_xid(child), VX_WATCH|VX_IDENT)) {
-               ret = -EPERM;
-               goto out_tsk;
-       }
 
-       ret = do_ptrace(child, request, addr, data);
-out_tsk:
-       put_task_struct(child);
-out:
-       unlock_kernel();
-       return ret;
-}
 
 asmlinkage void
 syscall_trace(struct pt_regs *regs, int entryexit)
@@ -742,30 +1286,17 @@ syscall_trace(struct pt_regs *regs, int entryexit)
        if (unlikely(current->audit_context) && entryexit)
                audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]), regs->gprs[2]);
 
-       if (!test_thread_flag(TIF_SYSCALL_TRACE))
-               goto out;
-       if (!(current->ptrace & PT_PTRACED))
-               goto out;
-       ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
-                                ? 0x80 : 0));
+       if (test_thread_flag(TIF_SYSCALL_TRACE)) {
+               tracehook_report_syscall(regs, entryexit);
 
-       /*
-        * If the debuffer has set an invalid system call number,
-        * we prepare to skip the system call restart handling.
-        */
-       if (!entryexit && regs->gprs[2] >= NR_syscalls)
-               regs->trap = -1;
-
-       /*
-        * this isn't the same as continuing with a signal, but it will do
-        * for normal use.  strace only continues with a signal if the
-        * stopping signal is not SIGTRAP.  -brl
-        */
-       if (current->exit_code) {
-               send_sig(current->exit_code, current, 1);
-               current->exit_code = 0;
+               /*
+                * If the debugger has set an invalid system call number,
+                * we prepare to skip the system call restart handling.
+                */
+               if (!entryexit && regs->gprs[2] >= NR_syscalls)
+                       regs->trap = -1;
        }
- out:
+
        if (unlikely(current->audit_context) && !entryexit)
                audit_syscall_entry(test_thread_flag(TIF_31BIT)?AUDIT_ARCH_S390:AUDIT_ARCH_S390X,
                                    regs->gprs[2], regs->orig_gpr2, regs->gprs[3],