/*
 *  PowerPC version
 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
 *
 *  Derived from "arch/m68k/kernel/ptrace.c"
 *  Copyright (C) 1994 by Hamish Macdonald
 *  Taken from linux/kernel/ptrace.c and modified for M680x0.
 *  linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
 *
 * Modified by Cort Dougan (cort@hq.fsmlabs.com)
 * and Paul Mackerras (paulus@samba.org).
 *
 * This file is subject to the terms and conditions of the GNU General
 * Public License.  See the file README.legal in the main directory of
 * this archive for more details.
 */

#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/regset.h>
#include <linux/tracehook.h>
#include <linux/elf.h>
#include <linux/user.h>
#include <linux/security.h>
#include <linux/signal.h>
#include <linux/seccomp.h>
#include <linux/audit.h>
#include <trace/syscall.h>
#include <linux/hw_breakpoint.h>
#include <linux/perf_event.h>
#include <linux/context_tracking.h>

#include <asm/uaccess.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/switch_to.h>

#define CREATE_TRACE_POINTS
#include <trace/events/syscalls.h>

/*
 * The parameter save area on the stack is used to store arguments being passed
 * to callee function and is located at fixed offset from stack pointer.
 */
#ifdef CONFIG_PPC32
#define PARAMETER_SAVE_AREA_OFFSET      24  /* bytes */
#else /* CONFIG_PPC32 */
#define PARAMETER_SAVE_AREA_OFFSET      48  /* bytes */
#endif

struct pt_regs_offset {
        const char *name;
        int offset;
};

#define STR(s)  #s                      /* convert to string */
#define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
#define GPR_OFFSET_NAME(num)    \
        {.name = STR(gpr##num), .offset = offsetof(struct pt_regs, gpr[num])}
#define REG_OFFSET_END {.name = NULL, .offset = 0}

static const struct pt_regs_offset regoffset_table[] = {
        GPR_OFFSET_NAME(0),
        GPR_OFFSET_NAME(1),
        GPR_OFFSET_NAME(2),
        GPR_OFFSET_NAME(3),
        GPR_OFFSET_NAME(4),
        GPR_OFFSET_NAME(5),
        GPR_OFFSET_NAME(6),
        GPR_OFFSET_NAME(7),
        GPR_OFFSET_NAME(8),
        GPR_OFFSET_NAME(9),
        GPR_OFFSET_NAME(10),
        GPR_OFFSET_NAME(11),
        GPR_OFFSET_NAME(12),
        GPR_OFFSET_NAME(13),
        GPR_OFFSET_NAME(14),
        GPR_OFFSET_NAME(15),
        GPR_OFFSET_NAME(16),
        GPR_OFFSET_NAME(17),
        GPR_OFFSET_NAME(18),
        GPR_OFFSET_NAME(19),
        GPR_OFFSET_NAME(20),
        GPR_OFFSET_NAME(21),
        GPR_OFFSET_NAME(22),
        GPR_OFFSET_NAME(23),
        GPR_OFFSET_NAME(24),
        GPR_OFFSET_NAME(25),
        GPR_OFFSET_NAME(26),
        GPR_OFFSET_NAME(27),
        GPR_OFFSET_NAME(28),
        GPR_OFFSET_NAME(29),
        GPR_OFFSET_NAME(30),
        GPR_OFFSET_NAME(31),
        REG_OFFSET_NAME(nip),
        REG_OFFSET_NAME(msr),
        REG_OFFSET_NAME(ctr),
        REG_OFFSET_NAME(link),
        REG_OFFSET_NAME(xer),
        REG_OFFSET_NAME(ccr),
#ifdef CONFIG_PPC64
        REG_OFFSET_NAME(softe),
#else
        REG_OFFSET_NAME(mq),
#endif
        REG_OFFSET_NAME(trap),
        REG_OFFSET_NAME(dar),
        REG_OFFSET_NAME(dsisr),
        REG_OFFSET_END,
};

/**
 * regs_query_register_offset() - query register offset from its name
 * @name:       the name of a register
 *
 * regs_query_register_offset() returns the offset of a register in struct
 * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 */
int regs_query_register_offset(const char *name)
{
        const struct pt_regs_offset *roff;
        for (roff = regoffset_table; roff->name != NULL; roff++)
                if (!strcmp(roff->name, name))
                        return roff->offset;
        return -EINVAL;
}

/**
 * regs_query_register_name() - query register name from its offset
 * @offset:     the offset of a register in struct pt_regs.
 *
 * regs_query_register_name() returns the name of a register from its
 * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
 */
const char *regs_query_register_name(unsigned int offset)
{
        const struct pt_regs_offset *roff;
        for (roff = regoffset_table; roff->name != NULL; roff++)
                if (roff->offset == offset)
                        return roff->name;
        return NULL;
}

/*
 * does not yet catch signals sent when the child dies.
 * in exit.c or in signal.c.
 */

/*
 * Set of msr bits that gdb can change on behalf of a process.
 */
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
#define MSR_DEBUGCHANGE 0
#else
#define MSR_DEBUGCHANGE (MSR_SE | MSR_BE)
#endif

/*
 * Max register writeable via put_reg
 */
#ifdef CONFIG_PPC32
#define PT_MAX_PUT_REG  PT_MQ
#else
#define PT_MAX_PUT_REG  PT_CCR
#endif

static unsigned long get_user_msr(struct task_struct *task)
{
        return task->thread.regs->msr | task->thread.fpexc_mode;
}

static int set_user_msr(struct task_struct *task, unsigned long msr)
{
        task->thread.regs->msr &= ~MSR_DEBUGCHANGE;
        task->thread.regs->msr |= msr & MSR_DEBUGCHANGE;
        return 0;
}

#ifdef CONFIG_PPC64
static int get_user_dscr(struct task_struct *task, unsigned long *data)
{
        *data = task->thread.dscr;
        return 0;
}

static int set_user_dscr(struct task_struct *task, unsigned long dscr)
{
        task->thread.dscr = dscr;
        task->thread.dscr_inherit = 1;
        return 0;
}
#else
static int get_user_dscr(struct task_struct *task, unsigned long *data)
{
        return -EIO;
}

static int set_user_dscr(struct task_struct *task, unsigned long dscr)
{
        return -EIO;
}
#endif

/*
 * We prevent mucking around with the reserved area of trap
 * which are used internally by the kernel.
 */
static int set_user_trap(struct task_struct *task, unsigned long trap)
{
        task->thread.regs->trap = trap & 0xfff0;
        return 0;
}

/*
 * Get contents of register REGNO in task TASK.
 */
int ptrace_get_reg(struct task_struct *task, int regno, unsigned long *data)
{
        if ((task->thread.regs == NULL) || !data)
                return -EIO;

        if (regno == PT_MSR) {
                *data = get_user_msr(task);
                return 0;
        }

        if (regno == PT_DSCR)
                return get_user_dscr(task, data);

        if (regno < (sizeof(struct pt_regs) / sizeof(unsigned long))) {
                *data = ((unsigned long *)task->thread.regs)[regno];
                return 0;
        }

        return -EIO;
}

/*
 * Write contents of register REGNO in task TASK.
 */
int ptrace_put_reg(struct task_struct *task, int regno, unsigned long data)
{
        if (task->thread.regs == NULL)
                return -EIO;

        if (regno == PT_MSR)
                return set_user_msr(task, data);
        if (regno == PT_TRAP)
                return set_user_trap(task, data);
        if (regno == PT_DSCR)
                return set_user_dscr(task, data);

        if (regno <= PT_MAX_PUT_REG) {
                ((unsigned long *)task->thread.regs)[regno] = data;
                return 0;
        }
        return -EIO;
}

static int gpr_get(struct task_struct *target, const struct user_regset *regset,
                   unsigned int pos, unsigned int count,
                   void *kbuf, void __user *ubuf)
{
        int i, ret;

        if (target->thread.regs == NULL)
                return -EIO;

        if (!FULL_REGS(target->thread.regs)) {
                /* We have a partial register set.  Fill 14-31 with bogus values */
                for (i = 14; i < 32; i++)
                        target->thread.regs->gpr[i] = NV_REG_POISON;
        }

        ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
                                  target->thread.regs,
                                  0, offsetof(struct pt_regs, msr));
        if (!ret) {
                unsigned long msr = get_user_msr(target);
                ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &msr,
                                          offsetof(struct pt_regs, msr),
                                          offsetof(struct pt_regs, msr) +
                                          sizeof(msr));
        }

        BUILD_BUG_ON(offsetof(struct pt_regs, orig_gpr3) !=
                     offsetof(struct pt_regs, msr) + sizeof(long));

        if (!ret)
                ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
                                          &target->thread.regs->orig_gpr3,
                                          offsetof(struct pt_regs, orig_gpr3),
                                          sizeof(struct pt_regs));
        if (!ret)
                ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
                                               sizeof(struct pt_regs), -1);

        return ret;
}

static int gpr_set(struct task_struct *target, const struct user_regset *regset,
                   unsigned int pos, unsigned int count,
                   const void *kbuf, const void __user *ubuf)
{
        unsigned long reg;
        int ret;

        if (target->thread.regs == NULL)
                return -EIO;

        CHECK_FULL_REGS(target->thread.regs);

        ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                 target->thread.regs,
                                 0, PT_MSR * sizeof(reg));

        if (!ret && count > 0) {
                ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &reg,
                                         PT_MSR * sizeof(reg),
                                         (PT_MSR + 1) * sizeof(reg));
                if (!ret)
                        ret = set_user_msr(target, reg);
        }

        BUILD_BUG_ON(offsetof(struct pt_regs, orig_gpr3) !=
                     offsetof(struct pt_regs, msr) + sizeof(long));

        if (!ret)
                ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                         &target->thread.regs->orig_gpr3,
                                         PT_ORIG_R3 * sizeof(reg),
                                         (PT_MAX_PUT_REG + 1) * sizeof(reg));

        if (PT_MAX_PUT_REG + 1 < PT_TRAP && !ret)
                ret = user_regset_copyin_ignore(
                        &pos, &count, &kbuf, &ubuf,
                        (PT_MAX_PUT_REG + 1) * sizeof(reg),
                        PT_TRAP * sizeof(reg));

        if (!ret && count > 0) {
                ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &reg,
                                         PT_TRAP * sizeof(reg),
                                         (PT_TRAP + 1) * sizeof(reg));
                if (!ret)
                        ret = set_user_trap(target, reg);
        }

        if (!ret)
                ret = user_regset_copyin_ignore(
                        &pos, &count, &kbuf, &ubuf,
                        (PT_TRAP + 1) * sizeof(reg), -1);

        return ret;
}

static int fpr_get(struct task_struct *target, const struct user_regset *regset,
                   unsigned int pos, unsigned int count,
                   void *kbuf, void __user *ubuf)
{
#ifdef CONFIG_VSX
        double buf[33];
        int i;
#endif
        flush_fp_to_thread(target);

#ifdef CONFIG_VSX
        /* copy to local buffer then write that out */
        for (i = 0; i < 32 ; i++)
                buf[i] = target->thread.TS_FPR(i);
        memcpy(&buf[32], &target->thread.fpscr, sizeof(double));
        return user_regset_copyout(&pos, &count, &kbuf, &ubuf, buf, 0, -1);

#else
        BUILD_BUG_ON(offsetof(struct thread_struct, fpscr) !=
                     offsetof(struct thread_struct, TS_FPR(32)));

        return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
                                   &target->thread.fpr, 0, -1);
#endif
}

static int fpr_set(struct task_struct *target, const struct user_regset *regset,
                   unsigned int pos, unsigned int count,
                   const void *kbuf, const void __user *ubuf)
{
#ifdef CONFIG_VSX
        double buf[33];
        int i;
#endif
        flush_fp_to_thread(target);

#ifdef CONFIG_VSX
        /* copy to local buffer then write that out */
        i = user_regset_copyin(&pos, &count, &kbuf, &ubuf, buf, 0, -1);
        if (i)
                return i;
        for (i = 0; i < 32 ; i++)
                target->thread.TS_FPR(i) = buf[i];
        memcpy(&target->thread.fpscr, &buf[32], sizeof(double));
        return 0;
#else
        BUILD_BUG_ON(offsetof(struct thread_struct, fpscr) !=
                     offsetof(struct thread_struct, TS_FPR(32)));

        return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                  &target->thread.fpr, 0, -1);
#endif
}

#ifdef CONFIG_ALTIVEC
/*
 * Get/set all the altivec registers vr0..vr31, vscr, vrsave, in one go.
 * The transfer totals 34 quadword.  Quadwords 0-31 contain the
 * corresponding vector registers.  Quadword 32 contains the vscr as the
 * last word (offset 12) within that quadword.  Quadword 33 contains the
 * vrsave as the first word (offset 0) within the quadword.
 *
 * This definition of the VMX state is compatible with the current PPC32
 * ptrace interface.  This allows signal handling and ptrace to use the
 * same structures.  This also simplifies the implementation of a bi-arch
 * (combined (32- and 64-bit) gdb.
 */

static int vr_active(struct task_struct *target,
                     const struct user_regset *regset)
{
        flush_altivec_to_thread(target);
        return target->thread.used_vr ? regset->n : 0;
}

static int vr_get(struct task_struct *target, const struct user_regset *regset,
                  unsigned int pos, unsigned int count,
                  void *kbuf, void __user *ubuf)
{
        int ret;

        flush_altivec_to_thread(target);

        BUILD_BUG_ON(offsetof(struct thread_struct, vscr) !=
                     offsetof(struct thread_struct, vr[32]));

        ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
                                  &target->thread.vr, 0,
                                  33 * sizeof(vector128));
        if (!ret) {
                /*
                 * Copy out only the low-order word of vrsave.
                 */
                union {
                        elf_vrreg_t reg;
                        u32 word;
                } vrsave;
                memset(&vrsave, 0, sizeof(vrsave));
                vrsave.word = target->thread.vrsave;
                ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &vrsave,
                                          33 * sizeof(vector128), -1);
        }

        return ret;
}

static int vr_set(struct task_struct *target, const struct user_regset *regset,
                  unsigned int pos, unsigned int count,
                  const void *kbuf, const void __user *ubuf)
{
        int ret;

        flush_altivec_to_thread(target);

        BUILD_BUG_ON(offsetof(struct thread_struct, vscr) !=
                     offsetof(struct thread_struct, vr[32]));

        ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                 &target->thread.vr, 0, 33 * sizeof(vector128));
        if (!ret && count > 0) {
                /*
                 * We use only the first word of vrsave.
                 */
                union {
                        elf_vrreg_t reg;
                        u32 word;
                } vrsave;
                memset(&vrsave, 0, sizeof(vrsave));
                vrsave.word = target->thread.vrsave;
                ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &vrsave,
                                         33 * sizeof(vector128), -1);
                if (!ret)
                        target->thread.vrsave = vrsave.word;
        }

        return ret;
}
#endif /* CONFIG_ALTIVEC */

#ifdef CONFIG_VSX
/*
 * Currently to set and and get all the vsx state, you need to call
 * the fp and VMX calls as well.  This only get/sets the lower 32
 * 128bit VSX registers.
 */

static int vsr_active(struct task_struct *target,
                      const struct user_regset *regset)
{
        flush_vsx_to_thread(target);
        return target->thread.used_vsr ? regset->n : 0;
}

static int vsr_get(struct task_struct *target, const struct user_regset *regset,
                   unsigned int pos, unsigned int count,
                   void *kbuf, void __user *ubuf)
{
        double buf[32];
        int ret, i;

        flush_vsx_to_thread(target);

        for (i = 0; i < 32 ; i++)
                buf[i] = target->thread.fpr[i][TS_VSRLOWOFFSET];
        ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
                                  buf, 0, 32 * sizeof(double));

        return ret;
}

static int vsr_set(struct task_struct *target, const struct user_regset *regset,
                   unsigned int pos, unsigned int count,
                   const void *kbuf, const void __user *ubuf)
{
        double buf[32];
        int ret,i;

        flush_vsx_to_thread(target);

        ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                 buf, 0, 32 * sizeof(double));
        for (i = 0; i < 32 ; i++)
                target->thread.fpr[i][TS_VSRLOWOFFSET] = buf[i];


        return ret;
}
#endif /* CONFIG_VSX */

#ifdef CONFIG_SPE

/*
 * For get_evrregs/set_evrregs functions 'data' has the following layout:
 *
 * struct {
 *   u32 evr[32];
 *   u64 acc;
 *   u32 spefscr;
 * }
 */

static int evr_active(struct task_struct *target,
                      const struct user_regset *regset)
{
        flush_spe_to_thread(target);
        return target->thread.used_spe ? regset->n : 0;
}

static int evr_get(struct task_struct *target, const struct user_regset *regset,
                   unsigned int pos, unsigned int count,
                   void *kbuf, void __user *ubuf)
{
        int ret;

        flush_spe_to_thread(target);

        ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
                                  &target->thread.evr,
                                  0, sizeof(target->thread.evr));

        BUILD_BUG_ON(offsetof(struct thread_struct, acc) + sizeof(u64) !=
                     offsetof(struct thread_struct, spefscr));

        if (!ret)
                ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
                                          &target->thread.acc,
                                          sizeof(target->thread.evr), -1);

        return ret;
}

static int evr_set(struct task_struct *target, const struct user_regset *regset,
                   unsigned int pos, unsigned int count,
                   const void *kbuf, const void __user *ubuf)
{
        int ret;

        flush_spe_to_thread(target);

        ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                 &target->thread.evr,
                                 0, sizeof(target->thread.evr));

        BUILD_BUG_ON(offsetof(struct thread_struct, acc) + sizeof(u64) !=
                     offsetof(struct thread_struct, spefscr));

        if (!ret)
                ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                         &target->thread.acc,
                                         sizeof(target->thread.evr), -1);

        return ret;
}
#endif /* CONFIG_SPE */


/*
 * These are our native regset flavors.
 */
enum powerpc_regset {
        REGSET_GPR,
        REGSET_FPR,
#ifdef CONFIG_ALTIVEC
        REGSET_VMX,
#endif
#ifdef CONFIG_VSX
        REGSET_VSX,
#endif
#ifdef CONFIG_SPE
        REGSET_SPE,
#endif
};

static const struct user_regset native_regsets[] = {
        [REGSET_GPR] = {
                .core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
                .size = sizeof(long), .align = sizeof(long),
                .get = gpr_get, .set = gpr_set
        },
        [REGSET_FPR] = {
                .core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
                .size = sizeof(double), .align = sizeof(double),
                .get = fpr_get, .set = fpr_set
        },
#ifdef CONFIG_ALTIVEC
        [REGSET_VMX] = {
                .core_note_type = NT_PPC_VMX, .n = 34,
                .size = sizeof(vector128), .align = sizeof(vector128),
                .active = vr_active, .get = vr_get, .set = vr_set
        },
#endif
#ifdef CONFIG_VSX
        [REGSET_VSX] = {
                .core_note_type = NT_PPC_VSX, .n = 32,
                .size = sizeof(double), .align = sizeof(double),
                .active = vsr_active, .get = vsr_get, .set = vsr_set
        },
#endif
#ifdef CONFIG_SPE
        [REGSET_SPE] = {
                .n = 35,
                .size = sizeof(u32), .align = sizeof(u32),
                .active = evr_active, .get = evr_get, .set = evr_set
        },
#endif
};

static const struct user_regset_view user_ppc_native_view = {
        .name = UTS_MACHINE, .e_machine = ELF_ARCH, .ei_osabi = ELF_OSABI,
        .regsets = native_regsets, .n = ARRAY_SIZE(native_regsets)
};

#ifdef CONFIG_PPC64
#include <linux/compat.h>

static int gpr32_get(struct task_struct *target,
                     const struct user_regset *regset,
                     unsigned int pos, unsigned int count,
                     void *kbuf, void __user *ubuf)
{
        const unsigned long *regs = &target->thread.regs->gpr[0];
        compat_ulong_t *k = kbuf;
        compat_ulong_t __user *u = ubuf;
        compat_ulong_t reg;
        int i;

        if (target->thread.regs == NULL)
                return -EIO;

        if (!FULL_REGS(target->thread.regs)) {
                /* We have a partial register set.  Fill 14-31 with bogus values */
                for (i = 14; i < 32; i++)
                        target->thread.regs->gpr[i] = NV_REG_POISON; 
        }

        pos /= sizeof(reg);
        count /= sizeof(reg);

        if (kbuf)
                for (; count > 0 && pos < PT_MSR; --count)
                        *k++ = regs[pos++];
        else
                for (; count > 0 && pos < PT_MSR; --count)
                        if (__put_user((compat_ulong_t) regs[pos++], u++))
                                return -EFAULT;

        if (count > 0 && pos == PT_MSR) {
                reg = get_user_msr(target);
                if (kbuf)
                        *k++ = reg;
                else if (__put_user(reg, u++))
                        return -EFAULT;
                ++pos;
                --count;
        }

        if (kbuf)
                for (; count > 0 && pos < PT_REGS_COUNT; --count)
                        *k++ = regs[pos++];
        else
                for (; count > 0 && pos < PT_REGS_COUNT; --count)
                        if (__put_user((compat_ulong_t) regs[pos++], u++))
                                return -EFAULT;

        kbuf = k;
        ubuf = u;
        pos *= sizeof(reg);
        count *= sizeof(reg);
        return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
                                        PT_REGS_COUNT * sizeof(reg), -1);
}

static int gpr32_set(struct task_struct *target,
                     const struct user_regset *regset,
                     unsigned int pos, unsigned int count,
                     const void *kbuf, const void __user *ubuf)
{
        unsigned long *regs = &target->thread.regs->gpr[0];
        const compat_ulong_t *k = kbuf;
        const compat_ulong_t __user *u = ubuf;
        compat_ulong_t reg;

        if (target->thread.regs == NULL)
                return -EIO;

        CHECK_FULL_REGS(target->thread.regs);

        pos /= sizeof(reg);
        count /= sizeof(reg);

        if (kbuf)
                for (; count > 0 && pos < PT_MSR; --count)
                        regs[pos++] = *k++;
        else
                for (; count > 0 && pos < PT_MSR; --count) {
                        if (__get_user(reg, u++))
                                return -EFAULT;
                        regs[pos++] = reg;
                }


        if (count > 0 && pos == PT_MSR) {
                if (kbuf)
                        reg = *k++;
                else if (__get_user(reg, u++))
                        return -EFAULT;
                set_user_msr(target, reg);
                ++pos;
                --count;
        }

        if (kbuf) {
                for (; count > 0 && pos <= PT_MAX_PUT_REG; --count)
                        regs[pos++] = *k++;
                for (; count > 0 && pos < PT_TRAP; --count, ++pos)
                        ++k;
        } else {
                for (; count > 0 && pos <= PT_MAX_PUT_REG; --count) {
                        if (__get_user(reg, u++))
                                return -EFAULT;
                        regs[pos++] = reg;
                }
                for (; count > 0 && pos < PT_TRAP; --count, ++pos)
                        if (__get_user(reg, u++))
                                return -EFAULT;
        }

        if (count > 0 && pos == PT_TRAP) {
                if (kbuf)
                        reg = *k++;
                else if (__get_user(reg, u++))
                        return -EFAULT;
                set_user_trap(target, reg);
                ++pos;
                --count;
        }

        kbuf = k;
        ubuf = u;
        pos *= sizeof(reg);
        count *= sizeof(reg);
        return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
                                         (PT_TRAP + 1) * sizeof(reg), -1);
}

/*
 * These are the regset flavors matching the CONFIG_PPC32 native set.
 */
static const struct user_regset compat_regsets[] = {
        [REGSET_GPR] = {
                .core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
                .size = sizeof(compat_long_t), .align = sizeof(compat_long_t),
                .get = gpr32_get, .set = gpr32_set
        },
        [REGSET_FPR] = {
                .core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
                .size = sizeof(double), .align = sizeof(double),
                .get = fpr_get, .set = fpr_set
        },
#ifdef CONFIG_ALTIVEC
        [REGSET_VMX] = {
                .core_note_type = NT_PPC_VMX, .n = 34,
                .size = sizeof(vector128), .align = sizeof(vector128),
                .active = vr_active, .get = vr_get, .set = vr_set
        },
#endif
#ifdef CONFIG_SPE
        [REGSET_SPE] = {
                .core_note_type = NT_PPC_SPE, .n = 35,
                .size = sizeof(u32), .align = sizeof(u32),
                .active = evr_active, .get = evr_get, .set = evr_set
        },
#endif
};

static const struct user_regset_view user_ppc_compat_view = {
        .name = "ppc", .e_machine = EM_PPC, .ei_osabi = ELF_OSABI,
        .regsets = compat_regsets, .n = ARRAY_SIZE(compat_regsets)
};
#endif  /* CONFIG_PPC64 */

const struct user_regset_view *task_user_regset_view(struct task_struct *task)
{
#ifdef CONFIG_PPC64
        if (test_tsk_thread_flag(task, TIF_32BIT))
                return &user_ppc_compat_view;
#endif
        return &user_ppc_native_view;
}


void user_enable_single_step(struct task_struct *task)
{
        struct pt_regs *regs = task->thread.regs;

        if (regs != NULL) {
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
                task->thread.dbcr0 &= ~DBCR0_BT;
                task->thread.dbcr0 |= DBCR0_IDM | DBCR0_IC;
                regs->msr |= MSR_DE;
#else
                regs->msr &= ~MSR_BE;
                regs->msr |= MSR_SE;
#endif
        }
        set_tsk_thread_flag(task, TIF_SINGLESTEP);
}

void user_enable_block_step(struct task_struct *task)
{
        struct pt_regs *regs = task->thread.regs;

        if (regs != NULL) {
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
                task->thread.dbcr0 &= ~DBCR0_IC;
                task->thread.dbcr0 = DBCR0_IDM | DBCR0_BT;
                regs->msr |= MSR_DE;
#else
                regs->msr &= ~MSR_SE;
                regs->msr |= MSR_BE;
#endif
        }
        set_tsk_thread_flag(task, TIF_SINGLESTEP);
}

void user_disable_single_step(struct task_struct *task)
{
        struct pt_regs *regs = task->thread.regs;

        if (regs != NULL) {
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
                /*
                 * The logic to disable single stepping should be as
                 * simple as turning off the Instruction Complete flag.
                 * And, after doing so, if all debug flags are off, turn
                 * off DBCR0(IDM) and MSR(DE) .... Torez
                 */
                task->thread.dbcr0 &= ~DBCR0_IC;
                /*
                 * Test to see if any of the DBCR_ACTIVE_EVENTS bits are set.
                 */
                if (!DBCR_ACTIVE_EVENTS(task->thread.dbcr0,
                                        task->thread.dbcr1)) {
                        /*
                         * All debug events were off.....
                         */
                        task->thread.dbcr0 &= ~DBCR0_IDM;
                        regs->msr &= ~MSR_DE;
                }
#else
                regs->msr &= ~(MSR_SE | MSR_BE);
#endif
        }
        clear_tsk_thread_flag(task, TIF_SINGLESTEP);
}

#ifdef CONFIG_HAVE_HW_BREAKPOINT
void ptrace_triggered(struct perf_event *bp,
                      struct perf_sample_data *data, struct pt_regs *regs)
{
        struct perf_event_attr attr;

        /*
         * Disable the breakpoint request here since ptrace has defined a
         * one-shot behaviour for breakpoint exceptions in PPC64.
         * The SIGTRAP signal is generated automatically for us in do_dabr().
         * We don't have to do anything about that here
         */
        attr = bp->attr;
        attr.disabled = true;
        modify_user_hw_breakpoint(bp, &attr);
}
#endif /* CONFIG_HAVE_HW_BREAKPOINT */

int ptrace_set_debugreg(struct task_struct *task, unsigned long addr,
                               unsigned long data)
{
#ifdef CONFIG_HAVE_HW_BREAKPOINT
        int ret;
        struct thread_struct *thread = &(task->thread);
        struct perf_event *bp;
        struct perf_event_attr attr;
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
#ifndef CONFIG_PPC_ADV_DEBUG_REGS
        struct arch_hw_breakpoint hw_brk;
#endif

        /* For ppc64 we support one DABR and no IABR's at the moment (ppc64).
         *  For embedded processors we support one DAC and no IAC's at the
         *  moment.
         */
        if (addr > 0)
                return -EINVAL;

        /* The bottom 3 bits in dabr are flags */
        if ((data & ~0x7UL) >= TASK_SIZE)
                return -EIO;

#ifndef CONFIG_PPC_ADV_DEBUG_REGS
        /* For processors using DABR (i.e. 970), the bottom 3 bits are flags.
         *  It was assumed, on previous implementations, that 3 bits were
         *  passed together with the data address, fitting the design of the
         *  DABR register, as follows:
         *
         *  bit 0: Read flag
         *  bit 1: Write flag
         *  bit 2: Breakpoint translation
         *
         *  Thus, we use them here as so.
         */

        /* Ensure breakpoint translation bit is set */
        if (data && !(data & HW_BRK_TYPE_TRANSLATE))
                return -EIO;
        hw_brk.address = data & (~HW_BRK_TYPE_DABR);
        hw_brk.type = (data & HW_BRK_TYPE_DABR) | HW_BRK_TYPE_PRIV_ALL;
        hw_brk.len = 8;
#ifdef CONFIG_HAVE_HW_BREAKPOINT
        bp = thread->ptrace_bps[0];
        if ((!data) || !(hw_brk.type & HW_BRK_TYPE_RDWR)) {
                if (bp) {
                        unregister_hw_breakpoint(bp);
                        thread->ptrace_bps[0] = NULL;
                }
                return 0;
        }
        if (bp) {
                attr = bp->attr;
                attr.bp_addr = hw_brk.address;
                arch_bp_generic_fields(hw_brk.type, &attr.bp_type);

                /* Enable breakpoint */
                attr.disabled = false;

                ret =  modify_user_hw_breakpoint(bp, &attr);
                if (ret) {
                        return ret;
                }
                thread->ptrace_bps[0] = bp;
                thread->hw_brk = hw_brk;
                return 0;

        }

        /* Create a new breakpoint request if one doesn't exist already */
        hw_breakpoint_init(&attr);
        attr.bp_addr = hw_brk.address;
        arch_bp_generic_fields(hw_brk.type,
                               &attr.bp_type);

        thread->ptrace_bps[0] = bp = register_user_hw_breakpoint(&attr,
                                               ptrace_triggered, NULL, task);
        if (IS_ERR(bp)) {
                thread->ptrace_bps[0] = NULL;
                return PTR_ERR(bp);
        }

#endif /* CONFIG_HAVE_HW_BREAKPOINT */
        task->thread.hw_brk = hw_brk;
#else /* CONFIG_PPC_ADV_DEBUG_REGS */
        /* As described above, it was assumed 3 bits were passed with the data
         *  address, but we will assume only the mode bits will be passed
         *  as to not cause alignment restrictions for DAC-based processors.
         */

        /* DAC's hold the whole address without any mode flags */
        task->thread.dac1 = data & ~0x3UL;

        if (task->thread.dac1 == 0) {
                dbcr_dac(task) &= ~(DBCR_DAC1R | DBCR_DAC1W);
                if (!DBCR_ACTIVE_EVENTS(task->thread.dbcr0,
                                        task->thread.dbcr1)) {
                        task->thread.regs->msr &= ~MSR_DE;
                        task->thread.dbcr0 &= ~DBCR0_IDM;
                }
                return 0;
        }

        /* Read or Write bits must be set */

        if (!(data & 0x3UL))
                return -EINVAL;

        /* Set the Internal Debugging flag (IDM bit 1) for the DBCR0
           register */
        task->thread.dbcr0 |= DBCR0_IDM;

        /* Check for write and read flags and set DBCR0
           accordingly */
        dbcr_dac(task) &= ~(DBCR_DAC1R|DBCR_DAC1W);
        if (data & 0x1UL)
                dbcr_dac(task) |= DBCR_DAC1R;
        if (data & 0x2UL)
                dbcr_dac(task) |= DBCR_DAC1W;
        task->thread.regs->msr |= MSR_DE;
#endif /* CONFIG_PPC_ADV_DEBUG_REGS */
        return 0;
}

/*
 * Called by kernel/ptrace.c when detaching..
 *
 * Make sure single step bits etc are not set.
 */
void ptrace_disable(struct task_struct *child)
{
        /* make sure the single step bit is not set. */
        user_disable_single_step(child);
}

#ifdef CONFIG_PPC_ADV_DEBUG_REGS
static long set_instruction_bp(struct task_struct *child,
                              struct ppc_hw_breakpoint *bp_info)
{
        int slot;
        int slot1_in_use = ((child->thread.dbcr0 & DBCR0_IAC1) != 0);
        int slot2_in_use = ((child->thread.dbcr0 & DBCR0_IAC2) != 0);
        int slot3_in_use = ((child->thread.dbcr0 & DBCR0_IAC3) != 0);
        int slot4_in_use = ((child->thread.dbcr0 & DBCR0_IAC4) != 0);

        if (dbcr_iac_range(child) & DBCR_IAC12MODE)
                slot2_in_use = 1;
        if (dbcr_iac_range(child) & DBCR_IAC34MODE)
                slot4_in_use = 1;

        if (bp_info->addr >= TASK_SIZE)
                return -EIO;

        if (bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT) {

                /* Make sure range is valid. */
                if (bp_info->addr2 >= TASK_SIZE)
                        return -EIO;

                /* We need a pair of IAC regsisters */
                if ((!slot1_in_use) && (!slot2_in_use)) {
                        slot = 1;
                        child->thread.iac1 = bp_info->addr;
                        child->thread.iac2 = bp_info->addr2;
                        child->thread.dbcr0 |= DBCR0_IAC1;
                        if (bp_info->addr_mode ==
                                        PPC_BREAKPOINT_MODE_RANGE_EXCLUSIVE)
                                dbcr_iac_range(child) |= DBCR_IAC12X;
                        else
                                dbcr_iac_range(child) |= DBCR_IAC12I;
#if CONFIG_PPC_ADV_DEBUG_IACS > 2
                } else if ((!slot3_in_use) && (!slot4_in_use)) {
                        slot = 3;
                        child->thread.iac3 = bp_info->addr;
                        child->thread.iac4 = bp_info->addr2;
                        child->thread.dbcr0 |= DBCR0_IAC3;
                        if (bp_info->addr_mode ==
                                        PPC_BREAKPOINT_MODE_RANGE_EXCLUSIVE)
                                dbcr_iac_range(child) |= DBCR_IAC34X;
                        else
                                dbcr_iac_range(child) |= DBCR_IAC34I;
#endif
                } else
                        return -ENOSPC;
        } else {
                /* We only need one.  If possible leave a pair free in
                 * case a range is needed later
                 */
                if (!slot1_in_use) {
                        /*
                         * Don't use iac1 if iac1-iac2 are free and either
                         * iac3 or iac4 (but not both) are free
                         */
                        if (slot2_in_use || (slot3_in_use == slot4_in_use)) {
                                slot = 1;
                                child->thread.iac1 = bp_info->addr;
                                child->thread.dbcr0 |= DBCR0_IAC1;
                                goto out;
                        }
                }
                if (!slot2_in_use) {
                        slot = 2;
                        child->thread.iac2 = bp_info->addr;
                        child->thread.dbcr0 |= DBCR0_IAC2;
#if CONFIG_PPC_ADV_DEBUG_IACS > 2
                } else if (!slot3_in_use) {
                        slot = 3;
                        child->thread.iac3 = bp_info->addr;
                        child->thread.dbcr0 |= DBCR0_IAC3;
                } else if (!slot4_in_use) {
                        slot = 4;
                        child->thread.iac4 = bp_info->addr;
                        child->thread.dbcr0 |= DBCR0_IAC4;
#endif
                } else
                        return -ENOSPC;
        }
out:
        child->thread.dbcr0 |= DBCR0_IDM;
        child->thread.regs->msr |= MSR_DE;

        return slot;
}

static int del_instruction_bp(struct task_struct *child, int slot)
{
        switch (slot) {
        case 1:
                if ((child->thread.dbcr0 & DBCR0_IAC1) == 0)
                        return -ENOENT;

                if (dbcr_iac_range(child) & DBCR_IAC12MODE) {
                        /* address range - clear slots 1 & 2 */
                        child->thread.iac2 = 0;
                        dbcr_iac_range(child) &= ~DBCR_IAC12MODE;
                }
                child->thread.iac1 = 0;
                child->thread.dbcr0 &= ~DBCR0_IAC1;
                break;
        case 2:
                if ((child->thread.dbcr0 & DBCR0_IAC2) == 0)
                        return -ENOENT;

                if (dbcr_iac_range(child) & DBCR_IAC12MODE)
                        /* used in a range */
                        return -EINVAL;
                child->thread.iac2 = 0;
                child->thread.dbcr0 &= ~DBCR0_IAC2;
                break;
#if CONFIG_PPC_ADV_DEBUG_IACS > 2
        case 3:
                if ((child->thread.dbcr0 & DBCR0_IAC3) == 0)
                        return -ENOENT;

                if (dbcr_iac_range(child) & DBCR_IAC34MODE) {
                        /* address range - clear slots 3 & 4 */
                        child->thread.iac4 = 0;
                        dbcr_iac_range(child) &= ~DBCR_IAC34MODE;
                }
                child->thread.iac3 = 0;
                child->thread.dbcr0 &= ~DBCR0_IAC3;
                break;
        case 4:
                if ((child->thread.dbcr0 & DBCR0_IAC4) == 0)
                        return -ENOENT;

                if (dbcr_iac_range(child) & DBCR_IAC34MODE)
                        /* Used in a range */
                        return -EINVAL;
                child->thread.iac4 = 0;
                child->thread.dbcr0 &= ~DBCR0_IAC4;
                break;
#endif
        default:
                return -EINVAL;
        }
        return 0;
}

static int set_dac(struct task_struct *child, struct ppc_hw_breakpoint *bp_info)
{
        int byte_enable =
                (bp_info->condition_mode >> PPC_BREAKPOINT_CONDITION_BE_SHIFT)
                & 0xf;
        int condition_mode =
                bp_info->condition_mode & PPC_BREAKPOINT_CONDITION_MODE;
        int slot;

        if (byte_enable && (condition_mode == 0))
                return -EINVAL;

        if (bp_info->addr >= TASK_SIZE)
                return -EIO;

        if ((dbcr_dac(child) & (DBCR_DAC1R | DBCR_DAC1W)) == 0) {
                slot = 1;
                if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
                        dbcr_dac(child) |= DBCR_DAC1R;
                if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)
                        dbcr_dac(child) |= DBCR_DAC1W;
                child->thread.dac1 = (unsigned long)bp_info->addr;
#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
                if (byte_enable) {
                        child->thread.dvc1 =
                                (unsigned long)bp_info->condition_value;
                        child->thread.dbcr2 |=
                                ((byte_enable << DBCR2_DVC1BE_SHIFT) |
                                 (condition_mode << DBCR2_DVC1M_SHIFT));
                }
#endif
#ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
        } else if (child->thread.dbcr2 & DBCR2_DAC12MODE) {
                /* Both dac1 and dac2 are part of a range */
                return -ENOSPC;
#endif
        } else if ((dbcr_dac(child) & (DBCR_DAC2R | DBCR_DAC2W)) == 0) {
                slot = 2;
                if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
                        dbcr_dac(child) |= DBCR_DAC2R;
                if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)
                        dbcr_dac(child) |= DBCR_DAC2W;
                child->thread.dac2 = (unsigned long)bp_info->addr;
#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
                if (byte_enable) {
                        child->thread.dvc2 =
                                (unsigned long)bp_info->condition_value;
                        child->thread.dbcr2 |=
                                ((byte_enable << DBCR2_DVC2BE_SHIFT) |
                                 (condition_mode << DBCR2_DVC2M_SHIFT));
                }
#endif
        } else
                return -ENOSPC;
        child->thread.dbcr0 |= DBCR0_IDM;
        child->thread.regs->msr |= MSR_DE;

        return slot + 4;
}

static int del_dac(struct task_struct *child, int slot)
{
        if (slot == 1) {
                if ((dbcr_dac(child) & (DBCR_DAC1R | DBCR_DAC1W)) == 0)
                        return -ENOENT;

                child->thread.dac1 = 0;
                dbcr_dac(child) &= ~(DBCR_DAC1R | DBCR_DAC1W);
#ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
                if (child->thread.dbcr2 & DBCR2_DAC12MODE) {
                        child->thread.dac2 = 0;
                        child->thread.dbcr2 &= ~DBCR2_DAC12MODE;
                }
                child->thread.dbcr2 &= ~(DBCR2_DVC1M | DBCR2_DVC1BE);
#endif
#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
                child->thread.dvc1 = 0;
#endif
        } else if (slot == 2) {
                if ((dbcr_dac(child) & (DBCR_DAC2R | DBCR_DAC2W)) == 0)
                        return -ENOENT;

#ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
                if (child->thread.dbcr2 & DBCR2_DAC12MODE)
                        /* Part of a range */
                        return -EINVAL;
                child->thread.dbcr2 &= ~(DBCR2_DVC2M | DBCR2_DVC2BE);
#endif
#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
                child->thread.dvc2 = 0;
#endif
                child->thread.dac2 = 0;
                dbcr_dac(child) &= ~(DBCR_DAC2R | DBCR_DAC2W);
        } else
                return -EINVAL;

        return 0;
}
#endif /* CONFIG_PPC_ADV_DEBUG_REGS */

#ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
static int set_dac_range(struct task_struct *child,
                         struct ppc_hw_breakpoint *bp_info)
{
        int mode = bp_info->addr_mode & PPC_BREAKPOINT_MODE_MASK;

        /* We don't allow range watchpoints to be used with DVC */
        if (bp_info->condition_mode)
                return -EINVAL;

        /*
         * Best effort to verify the address range.  The user/supervisor bits
         * prevent trapping in kernel space, but let's fail on an obvious bad
         * range.  The simple test on the mask is not fool-proof, and any
         * exclusive range will spill over into kernel space.
         */
        if (bp_info->addr >= TASK_SIZE)
                return -EIO;
        if (mode == PPC_BREAKPOINT_MODE_MASK) {
                /*
                 * dac2 is a bitmask.  Don't allow a mask that makes a
                 * kernel space address from a valid dac1 value
                 */
                if (~((unsigned long)bp_info->addr2) >= TASK_SIZE)
                        return -EIO;
        } else {
                /*
                 * For range breakpoints, addr2 must also be a valid address
                 */
                if (bp_info->addr2 >= TASK_SIZE)
                        return -EIO;
        }

        if (child->thread.dbcr0 &
            (DBCR0_DAC1R | DBCR0_DAC1W | DBCR0_DAC2R | DBCR0_DAC2W))
                return -ENOSPC;

        if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
                child->thread.dbcr0 |= (DBCR0_DAC1R | DBCR0_IDM);
        if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)
                child->thread.dbcr0 |= (DBCR0_DAC1W | DBCR0_IDM);
        child->thread.dac1 = bp_info->addr;
        child->thread.dac2 = bp_info->addr2;
        if (mode == PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE)
                child->thread.dbcr2  |= DBCR2_DAC12M;
        else if (mode == PPC_BREAKPOINT_MODE_RANGE_EXCLUSIVE)
                child->thread.dbcr2  |= DBCR2_DAC12MX;
        else    /* PPC_BREAKPOINT_MODE_MASK */
                child->thread.dbcr2  |= DBCR2_DAC12MM;
        child->thread.regs->msr |= MSR_DE;

        return 5;
}
#endif /* CONFIG_PPC_ADV_DEBUG_DAC_RANGE */

static long ppc_set_hwdebug(struct task_struct *child,
                     struct ppc_hw_breakpoint *bp_info)
{
#ifdef CONFIG_HAVE_HW_BREAKPOINT
        int len = 0;
        struct thread_struct *thread = &(child->thread);
        struct perf_event *bp;
        struct perf_event_attr attr;
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
#ifndef CONFIG_PPC_ADV_DEBUG_REGS
        struct arch_hw_breakpoint brk;
#endif

        if (bp_info->version != 1)
                return -ENOTSUPP;
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
        /*
         * Check for invalid flags and combinations
         */
        if ((bp_info->trigger_type == 0) ||
            (bp_info->trigger_type & ~(PPC_BREAKPOINT_TRIGGER_EXECUTE |
                                       PPC_BREAKPOINT_TRIGGER_RW)) ||
            (bp_info->addr_mode & ~PPC_BREAKPOINT_MODE_MASK) ||
            (bp_info->condition_mode &
             ~(PPC_BREAKPOINT_CONDITION_MODE |
               PPC_BREAKPOINT_CONDITION_BE_ALL)))
                return -EINVAL;
#if CONFIG_PPC_ADV_DEBUG_DVCS == 0
        if (bp_info->condition_mode != PPC_BREAKPOINT_CONDITION_NONE)
                return -EINVAL;
#endif

        if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_EXECUTE) {
                if ((bp_info->trigger_type != PPC_BREAKPOINT_TRIGGER_EXECUTE) ||
                    (bp_info->condition_mode != PPC_BREAKPOINT_CONDITION_NONE))
                        return -EINVAL;
                return set_instruction_bp(child, bp_info);
        }
        if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_EXACT)
                return set_dac(child, bp_info);

#ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
        return set_dac_range(child, bp_info);
#else
        return -EINVAL;
#endif
#else /* !CONFIG_PPC_ADV_DEBUG_DVCS */
        /*
         * We only support one data breakpoint
         */
        if ((bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_RW) == 0 ||
            (bp_info->trigger_type & ~PPC_BREAKPOINT_TRIGGER_RW) != 0 ||
            bp_info->condition_mode != PPC_BREAKPOINT_CONDITION_NONE)
                return -EINVAL;

        if ((unsigned long)bp_info->addr >= TASK_SIZE)
                return -EIO;

        brk.address = bp_info->addr & ~7UL;
        brk.type = HW_BRK_TYPE_TRANSLATE;
        brk.len = 8;
        if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
                brk.type |= HW_BRK_TYPE_READ;
        if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)
                brk.type |= HW_BRK_TYPE_WRITE;
#ifdef CONFIG_HAVE_HW_BREAKPOINT
        /*
         * Check if the request is for 'range' breakpoints. We can
         * support it if range < 8 bytes.
         */
        if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE)
                len = bp_info->addr2 - bp_info->addr;
        else if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_EXACT)
                len = 1;
        else
                return -EINVAL;
        bp = thread->ptrace_bps[0];
        if (bp)
                return -ENOSPC;

        /* Create a new breakpoint request if one doesn't exist already */
        hw_breakpoint_init(&attr);
        attr.bp_addr = (unsigned long)bp_info->addr & ~HW_BREAKPOINT_ALIGN;
        attr.bp_len = len;
        arch_bp_generic_fields(brk.type, &attr.bp_type);

        thread->ptrace_bps[0] = bp = register_user_hw_breakpoint(&attr,
                                               ptrace_triggered, NULL, child);
        if (IS_ERR(bp)) {
                thread->ptrace_bps[0] = NULL;
                return PTR_ERR(bp);
        }

        return 1;
#endif /* CONFIG_HAVE_HW_BREAKPOINT */

        if (bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT)
                return -EINVAL;

        if (child->thread.hw_brk.address)
                return -ENOSPC;

        child->thread.hw_brk = brk;

        return 1;
#endif /* !CONFIG_PPC_ADV_DEBUG_DVCS */
}

static long ppc_del_hwdebug(struct task_struct *child, long data)
{
#ifdef CONFIG_HAVE_HW_BREAKPOINT
        int ret = 0;
        struct thread_struct *thread = &(child->thread);
        struct perf_event *bp;
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
        int rc;

        if (data <= 4)
                rc = del_instruction_bp(child, (int)data);
        else
                rc = del_dac(child, (int)data - 4);

        if (!rc) {
                if (!DBCR_ACTIVE_EVENTS(child->thread.dbcr0,
                                        child->thread.dbcr1)) {
                        child->thread.dbcr0 &= ~DBCR0_IDM;
                        child->thread.regs->msr &= ~MSR_DE;
                }
        }
        return rc;
#else
        if (data != 1)
                return -EINVAL;

#ifdef CONFIG_HAVE_HW_BREAKPOINT
        bp = thread->ptrace_bps[0];
        if (bp) {
                unregister_hw_breakpoint(bp);
                thread->ptrace_bps[0] = NULL;
        } else
                ret = -ENOENT;
        return ret;
#else /* CONFIG_HAVE_HW_BREAKPOINT */
        if (child->thread.hw_brk.address == 0)
                return -ENOENT;

        child->thread.hw_brk.address = 0;
        child->thread.hw_brk.type = 0;
#endif /* CONFIG_HAVE_HW_BREAKPOINT */

        return 0;
#endif
}

long arch_ptrace(struct task_struct *child, long request,
                 unsigned long addr, unsigned long data)
{
        int ret = -EPERM;
        void __user *datavp = (void __user *) data;
        unsigned long __user *datalp = datavp;

        switch (request) {
        /* read the word at location addr in the USER area. */
        case PTRACE_PEEKUSR: {
                unsigned long index, tmp;

                ret = -EIO;
                /* convert to index and check */
#ifdef CONFIG_PPC32
                index = addr >> 2;
                if ((addr & 3) || (index > PT_FPSCR)
                    || (child->thread.regs == NULL))
#else
                index = addr >> 3;
                if ((addr & 7) || (index > PT_FPSCR))
#endif
                        break;

                CHECK_FULL_REGS(child->thread.regs);
                if (index < PT_FPR0) {
                        ret = ptrace_get_reg(child, (int) index, &tmp);
                        if (ret)
                                break;
                } else {
                        unsigned int fpidx = index - PT_FPR0;

                        flush_fp_to_thread(child);
                        if (fpidx < (PT_FPSCR - PT_FPR0))
                                tmp = ((unsigned long *)child->thread.fpr)
                                        [fpidx * TS_FPRWIDTH];
                        else
                                tmp = child->thread.fpscr.val;
                }
                ret = put_user(tmp, datalp);
                break;
        }

        /* write the word at location addr in the USER area */
        case PTRACE_POKEUSR: {
                unsigned long index;

                ret = -EIO;
                /* convert to index and check */
#ifdef CONFIG_PPC32
                index = addr >> 2;
                if ((addr & 3) || (index > PT_FPSCR)
                    || (child->thread.regs == NULL))
#else
                index = addr >> 3;
                if ((addr & 7) || (index > PT_FPSCR))
#endif
                        break;

                CHECK_FULL_REGS(child->thread.regs);
                if (index < PT_FPR0) {
                        ret = ptrace_put_reg(child, index, data);
                } else {
                        unsigned int fpidx = index - PT_FPR0;

                        flush_fp_to_thread(child);
                        if (fpidx < (PT_FPSCR - PT_FPR0))
                                ((unsigned long *)child->thread.fpr)
                                        [fpidx * TS_FPRWIDTH] = data;
                        else
                                child->thread.fpscr.val = data;
                        ret = 0;
                }
                break;
        }

        case PPC_PTRACE_GETHWDBGINFO: {
                struct ppc_debug_info dbginfo;

                dbginfo.version = 1;
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
                dbginfo.num_instruction_bps = CONFIG_PPC_ADV_DEBUG_IACS;
                dbginfo.num_data_bps = CONFIG_PPC_ADV_DEBUG_DACS;
                dbginfo.num_condition_regs = CONFIG_PPC_ADV_DEBUG_DVCS;
                dbginfo.data_bp_alignment = 4;
                dbginfo.sizeof_condition = 4;
                dbginfo.features = PPC_DEBUG_FEATURE_INSN_BP_RANGE |
                                   PPC_DEBUG_FEATURE_INSN_BP_MASK;
#ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
                dbginfo.features |=
                                   PPC_DEBUG_FEATURE_DATA_BP_RANGE |
                                   PPC_DEBUG_FEATURE_DATA_BP_MASK;
#endif
#else /* !CONFIG_PPC_ADV_DEBUG_REGS */
                dbginfo.num_instruction_bps = 0;
                dbginfo.num_data_bps = 1;
                dbginfo.num_condition_regs = 0;
#ifdef CONFIG_PPC64
                dbginfo.data_bp_alignment = 8;
#else
                dbginfo.data_bp_alignment = 4;
#endif
                dbginfo.sizeof_condition = 0;
#ifdef CONFIG_HAVE_HW_BREAKPOINT
                dbginfo.features = PPC_DEBUG_FEATURE_DATA_BP_RANGE;
                if (cpu_has_feature(CPU_FTR_DAWR))
                        dbginfo.features |= PPC_DEBUG_FEATURE_DATA_BP_DAWR;
#else
                dbginfo.features = 0;
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
#endif /* CONFIG_PPC_ADV_DEBUG_REGS */

                if (!access_ok(VERIFY_WRITE, datavp,
                               sizeof(struct ppc_debug_info)))
                        return -EFAULT;
                ret = __copy_to_user(datavp, &dbginfo,
                                     sizeof(struct ppc_debug_info)) ?
                      -EFAULT : 0;
                break;
        }

        case PPC_PTRACE_SETHWDEBUG: {
                struct ppc_hw_breakpoint bp_info;

                if (!access_ok(VERIFY_READ, datavp,
                               sizeof(struct ppc_hw_breakpoint)))
                        return -EFAULT;
                ret = __copy_from_user(&bp_info, datavp,
                                       sizeof(struct ppc_hw_breakpoint)) ?
                      -EFAULT : 0;
                if (!ret)
                        ret = ppc_set_hwdebug(child, &bp_info);
                break;
        }

        case PPC_PTRACE_DELHWDEBUG: {
                ret = ppc_del_hwdebug(child, data);
                break;
        }

        case PTRACE_GET_DEBUGREG: {
#ifndef CONFIG_PPC_ADV_DEBUG_REGS
                unsigned long dabr_fake;
#endif
                ret = -EINVAL;
                /* We only support one DABR and no IABRS at the moment */
                if (addr > 0)
                        break;
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
                ret = put_user(child->thread.dac1, datalp);
#else
                dabr_fake = ((child->thread.hw_brk.address & (~HW_BRK_TYPE_DABR)) |
                             (child->thread.hw_brk.type & HW_BRK_TYPE_DABR));
                ret = put_user(dabr_fake, datalp);
#endif
                break;
        }

        case PTRACE_SET_DEBUGREG:
                ret = ptrace_set_debugreg(child, addr, data);
                break;

#ifdef CONFIG_PPC64
        case PTRACE_GETREGS64:
#endif
        case PTRACE_GETREGS:    /* Get all pt_regs from the child. */
                return copy_regset_to_user(child, &user_ppc_native_view,
                                           REGSET_GPR,
                                           0, sizeof(struct pt_regs),
                                           datavp);

#ifdef CONFIG_PPC64
        case PTRACE_SETREGS64:
#endif
        case PTRACE_SETREGS:    /* Set all gp regs in the child. */
                return copy_regset_from_user(child, &user_ppc_native_view,
                                             REGSET_GPR,
                                             0, sizeof(struct pt_regs),
                                             datavp);

        case PTRACE_GETFPREGS: /* Get the child FPU state (FPR0...31 + FPSCR) */
                return copy_regset_to_user(child, &user_ppc_native_view,
                                           REGSET_FPR,
                                           0, sizeof(elf_fpregset_t),
                                           datavp);

        case PTRACE_SETFPREGS: /* Set the child FPU state (FPR0...31 + FPSCR) */
                return copy_regset_from_user(child, &user_ppc_native_view,
                                             REGSET_FPR,
                                             0, sizeof(elf_fpregset_t),
                                             datavp);

#ifdef CONFIG_ALTIVEC
        case PTRACE_GETVRREGS:
                return copy_regset_to_user(child, &user_ppc_native_view,
                                           REGSET_VMX,
                                           0, (33 * sizeof(vector128) +
                                               sizeof(u32)),
                                           datavp);

        case PTRACE_SETVRREGS:
                return copy_regset_from_user(child, &user_ppc_native_view,
                                             REGSET_VMX,
                                             0, (33 * sizeof(vector128) +
                                                 sizeof(u32)),
                                             datavp);
#endif
#ifdef CONFIG_VSX
        case PTRACE_GETVSRREGS:
                return copy_regset_to_user(child, &user_ppc_native_view,
                                           REGSET_VSX,
                                           0, 32 * sizeof(double),
                                           datavp);

        case PTRACE_SETVSRREGS:
                return copy_regset_from_user(child, &user_ppc_native_view,
                                             REGSET_VSX,
                                             0, 32 * sizeof(double),
                                             datavp);
#endif
#ifdef CONFIG_SPE
        case PTRACE_GETEVRREGS:
                /* Get the child spe register state. */
                return copy_regset_to_user(child, &user_ppc_native_view,
                                           REGSET_SPE, 0, 35 * sizeof(u32),
                                           datavp);

        case PTRACE_SETEVRREGS:
                /* Set the child spe register state. */
                return copy_regset_from_user(child, &user_ppc_native_view,
                                             REGSET_SPE, 0, 35 * sizeof(u32),
                                             datavp);
#endif

        default:
                ret = ptrace_request(child, request, addr, data);
                break;
        }
        return ret;
}

/*
 * We must return the syscall number to actually look up in the table.
 * This can be -1L to skip running any syscall at all.
 */
long do_syscall_trace_enter(struct pt_regs *regs)
{
        long ret = 0;

        user_exit();

        secure_computing_strict(regs->gpr[0]);

        if (test_thread_flag(TIF_SYSCALL_TRACE) &&
            tracehook_report_syscall_entry(regs))
                /*
                 * Tracing decided this syscall should not happen.
                 * We'll return a bogus call number to get an ENOSYS
                 * error, but leave the original number in regs->gpr[0].
                 */
                ret = -1L;

        if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
                trace_sys_enter(regs, regs->gpr[0]);

#ifdef CONFIG_PPC64
        if (!is_32bit_task())
                audit_syscall_entry(AUDIT_ARCH_PPC64,
                                    regs->gpr[0],
                                    regs->gpr[3], regs->gpr[4],
                                    regs->gpr[5], regs->gpr[6]);
        else
#endif
                audit_syscall_entry(AUDIT_ARCH_PPC,
                                    regs->gpr[0],
                                    regs->gpr[3] & 0xffffffff,
                                    regs->gpr[4] & 0xffffffff,
                                    regs->gpr[5] & 0xffffffff,
                                    regs->gpr[6] & 0xffffffff);

        return ret ?: regs->gpr[0];
}

void do_syscall_trace_leave(struct pt_regs *regs)
{
        int step;

        audit_syscall_exit(regs);

        if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
                trace_sys_exit(regs, regs->result);

        step = test_thread_flag(TIF_SINGLESTEP);
        if (step || test_thread_flag(TIF_SYSCALL_TRACE))
                tracehook_report_syscall_exit(regs, step);

        user_enter();
}