// SPDX-License-Identifier: GPL-2.0-only
/* ptrace.c: Sparc process tracing support.
 *
 * Copyright (C) 1996, 2008 David S. Miller (davem@davemloft.net)
 * Copyright (C) 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
 *
 * Based upon code written by Ross Biro, Linus Torvalds, Bob Manson,
 * and David Mosberger.
 *
 * Added Linux support -miguel (weird, eh?, the original code was meant
 * to emulate SunOS).
 */

#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/export.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/smp.h>
#include <linux/security.h>
#include <linux/seccomp.h>
#include <linux/audit.h>
#include <linux/signal.h>
#include <linux/regset.h>
#include <trace/syscall.h>
#include <linux/compat.h>
#include <linux/elf.h>
#include <linux/context_tracking.h>

#include <asm/asi.h>
#include <linux/uaccess.h>
#include <asm/psrcompat.h>
#include <asm/visasm.h>
#include <asm/spitfire.h>
#include <asm/page.h>
#include <asm/cpudata.h>
#include <asm/cacheflush.h>

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

#include "entry.h"

/* #define ALLOW_INIT_TRACING */

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

#define REG_OFFSET_NAME(n, r) \
        {.name = n, .offset = (PT_V9_##r)}
#define REG_OFFSET_END {.name = NULL, .offset = 0}

static const struct pt_regs_offset regoffset_table[] = {
        REG_OFFSET_NAME("g0", G0),
        REG_OFFSET_NAME("g1", G1),
        REG_OFFSET_NAME("g2", G2),
        REG_OFFSET_NAME("g3", G3),
        REG_OFFSET_NAME("g4", G4),
        REG_OFFSET_NAME("g5", G5),
        REG_OFFSET_NAME("g6", G6),
        REG_OFFSET_NAME("g7", G7),

        REG_OFFSET_NAME("i0", I0),
        REG_OFFSET_NAME("i1", I1),
        REG_OFFSET_NAME("i2", I2),
        REG_OFFSET_NAME("i3", I3),
        REG_OFFSET_NAME("i4", I4),
        REG_OFFSET_NAME("i5", I5),
        REG_OFFSET_NAME("i6", I6),
        REG_OFFSET_NAME("i7", I7),

        REG_OFFSET_NAME("tstate", TSTATE),
        REG_OFFSET_NAME("pc", TPC),
        REG_OFFSET_NAME("npc", TNPC),
        REG_OFFSET_NAME("y", Y),
        REG_OFFSET_NAME("lr", I7),

        REG_OFFSET_END,
};

/*
 * Called by kernel/ptrace.c when detaching..
 *
 * Make sure single step bits etc are not set.
 */
void ptrace_disable(struct task_struct *child)
{
        /* nothing to do */
}

/* To get the necessary page struct, access_process_vm() first calls
 * get_user_pages().  This has done a flush_dcache_page() on the
 * accessed page.  Then our caller (copy_{to,from}_user_page()) did
 * to memcpy to read/write the data from that page.
 *
 * Now, the only thing we have to do is:
 * 1) flush the D-cache if it's possible than an illegal alias
 *    has been created
 * 2) flush the I-cache if this is pre-cheetah and we did a write
 */
void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
                         unsigned long uaddr, void *kaddr,
                         unsigned long len, int write)
{
        BUG_ON(len > PAGE_SIZE);

        if (tlb_type == hypervisor)
                return;

        preempt_disable();

#ifdef DCACHE_ALIASING_POSSIBLE
        /* If bit 13 of the kernel address we used to access the
         * user page is the same as the virtual address that page
         * is mapped to in the user's address space, we can skip the
         * D-cache flush.
         */
        if ((uaddr ^ (unsigned long) kaddr) & (1UL << 13)) {
                unsigned long start = __pa(kaddr);
                unsigned long end = start + len;
                unsigned long dcache_line_size;

                dcache_line_size = local_cpu_data().dcache_line_size;

                if (tlb_type == spitfire) {
                        for (; start < end; start += dcache_line_size)
                                spitfire_put_dcache_tag(start & 0x3fe0, 0x0);
                } else {
                        start &= ~(dcache_line_size - 1);
                        for (; start < end; start += dcache_line_size)
                                __asm__ __volatile__(
                                        "stxa %%g0, [%0] %1\n\t"
                                        "membar #Sync"
                                        : /* no outputs */
                                        : "r" (start),
                                        "i" (ASI_DCACHE_INVALIDATE));
                }
        }
#endif
        if (write && tlb_type == spitfire) {
                unsigned long start = (unsigned long) kaddr;
                unsigned long end = start + len;
                unsigned long icache_line_size;

                icache_line_size = local_cpu_data().icache_line_size;

                for (; start < end; start += icache_line_size)
                        flushi(start);
        }

        preempt_enable();
}
EXPORT_SYMBOL_GPL(flush_ptrace_access);

static int get_from_target(struct task_struct *target, unsigned long uaddr,
                           void *kbuf, int len)
{
        if (target == current) {
                if (copy_from_user(kbuf, (void __user *) uaddr, len))
                        return -EFAULT;
        } else {
                int len2 = access_process_vm(target, uaddr, kbuf, len,
                                FOLL_FORCE);
                if (len2 != len)
                        return -EFAULT;
        }
        return 0;
}

static int set_to_target(struct task_struct *target, unsigned long uaddr,
                         void *kbuf, int len)
{
        if (target == current) {
                if (copy_to_user((void __user *) uaddr, kbuf, len))
                        return -EFAULT;
        } else {
                int len2 = access_process_vm(target, uaddr, kbuf, len,
                                FOLL_FORCE | FOLL_WRITE);
                if (len2 != len)
                        return -EFAULT;
        }
        return 0;
}

static int regwindow64_get(struct task_struct *target,
                           const struct pt_regs *regs,
                           struct reg_window *wbuf)
{
        unsigned long rw_addr = regs->u_regs[UREG_I6];

        if (!test_thread_64bit_stack(rw_addr)) {
                struct reg_window32 win32;
                int i;

                if (get_from_target(target, rw_addr, &win32, sizeof(win32)))
                        return -EFAULT;
                for (i = 0; i < 8; i++)
                        wbuf->locals[i] = win32.locals[i];
                for (i = 0; i < 8; i++)
                        wbuf->ins[i] = win32.ins[i];
        } else {
                rw_addr += STACK_BIAS;
                if (get_from_target(target, rw_addr, wbuf, sizeof(*wbuf)))
                        return -EFAULT;
        }

        return 0;
}

static int regwindow64_set(struct task_struct *target,
                           const struct pt_regs *regs,
                           struct reg_window *wbuf)
{
        unsigned long rw_addr = regs->u_regs[UREG_I6];

        if (!test_thread_64bit_stack(rw_addr)) {
                struct reg_window32 win32;
                int i;

                for (i = 0; i < 8; i++)
                        win32.locals[i] = wbuf->locals[i];
                for (i = 0; i < 8; i++)
                        win32.ins[i] = wbuf->ins[i];

                if (set_to_target(target, rw_addr, &win32, sizeof(win32)))
                        return -EFAULT;
        } else {
                rw_addr += STACK_BIAS;
                if (set_to_target(target, rw_addr, wbuf, sizeof(*wbuf)))
                        return -EFAULT;
        }

        return 0;
}

enum sparc_regset {
        REGSET_GENERAL,
        REGSET_FP,
};

static int genregs64_get(struct task_struct *target,
                         const struct user_regset *regset,
                         struct membuf to)
{
        const struct pt_regs *regs = task_pt_regs(target);
        struct reg_window window;

        if (target == current)
                flushw_user();

        membuf_write(&to, regs->u_regs, 16 * sizeof(u64));
        if (!to.left)
                return 0;
        if (regwindow64_get(target, regs, &window))
                return -EFAULT;
        membuf_write(&to, &window, 16 * sizeof(u64));
        /* TSTATE, TPC, TNPC */
        membuf_write(&to, &regs->tstate, 3 * sizeof(u64));
        return membuf_store(&to, (u64)regs->y);
}

static int genregs64_set(struct task_struct *target,
                         const struct user_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;

        if (target == current)
                flushw_user();

        ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                 regs->u_regs,
                                 0, 16 * sizeof(u64));
        if (!ret && count && pos < (32 * sizeof(u64))) {
                struct reg_window window;

                if (regwindow64_get(target, regs, &window))
                        return -EFAULT;

                ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                         &window,
                                         16 * sizeof(u64),
                                         32 * sizeof(u64));

                if (!ret &&
                    regwindow64_set(target, regs, &window))
                        return -EFAULT;
        }

        if (!ret && count > 0) {
                unsigned long tstate;

                /* TSTATE */
                ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                         &tstate,
                                         32 * sizeof(u64),
                                         33 * sizeof(u64));
                if (!ret) {
                        /* Only the condition codes and the "in syscall"
                         * state can be modified in the %tstate register.
                         */
                        tstate &= (TSTATE_ICC | TSTATE_XCC | TSTATE_SYSCALL);
                        regs->tstate &= ~(TSTATE_ICC | TSTATE_XCC | TSTATE_SYSCALL);
                        regs->tstate |= tstate;
                }
        }

        if (!ret) {
                /* TPC, TNPC */
                ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                         &regs->tpc,
                                         33 * sizeof(u64),
                                         35 * sizeof(u64));
        }

        if (!ret) {
                unsigned long y = regs->y;

                ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                         &y,
                                         35 * sizeof(u64),
                                         36 * sizeof(u64));
                if (!ret)
                        regs->y = y;
        }

        if (!ret)
                ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
                                                36 * sizeof(u64), -1);

        return ret;
}

static int fpregs64_get(struct task_struct *target,
                        const struct user_regset *regset,
                        struct membuf to)
{
        struct thread_info *t = task_thread_info(target);
        unsigned long fprs;

        if (target == current)
                save_and_clear_fpu();

        fprs = t->fpsaved[0];

        if (fprs & FPRS_DL)
                membuf_write(&to, t->fpregs, 16 * sizeof(u64));
        else
                membuf_zero(&to, 16 * sizeof(u64));

        if (fprs & FPRS_DU)
                membuf_write(&to, t->fpregs + 16, 16 * sizeof(u64));
        else
                membuf_zero(&to, 16 * sizeof(u64));
        if (fprs & FPRS_FEF) {
                membuf_store(&to, t->xfsr[0]);
                membuf_store(&to, t->gsr[0]);
        } else {
                membuf_zero(&to, 2 * sizeof(u64));
        }
        return membuf_store(&to, fprs);
}

static int fpregs64_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 *fpregs = task_thread_info(target)->fpregs;
        unsigned long fprs;
        int ret;

        if (target == current)
                save_and_clear_fpu();

        ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                 fpregs,
                                 0, 32 * sizeof(u64));
        if (!ret)
                ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                         task_thread_info(target)->xfsr,
                                         32 * sizeof(u64),
                                         33 * sizeof(u64));
        if (!ret)
                ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                         task_thread_info(target)->gsr,
                                         33 * sizeof(u64),
                                         34 * sizeof(u64));

        fprs = task_thread_info(target)->fpsaved[0];
        if (!ret && count > 0) {
                ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                         &fprs,
                                         34 * sizeof(u64),
                                         35 * sizeof(u64));
        }

        fprs |= (FPRS_FEF | FPRS_DL | FPRS_DU);
        task_thread_info(target)->fpsaved[0] = fprs;

        if (!ret)
                ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
                                                35 * sizeof(u64), -1);
        return ret;
}

static const struct user_regset sparc64_regsets[] = {
        /* Format is:
         *      G0 --> G7
         *      O0 --> O7
         *      L0 --> L7
         *      I0 --> I7
         *      TSTATE, TPC, TNPC, Y
         */
        [REGSET_GENERAL] = {
                .core_note_type = NT_PRSTATUS,
                .n = 36,
                .size = sizeof(u64), .align = sizeof(u64),
                .regset_get = genregs64_get, .set = genregs64_set
        },
        /* Format is:
         *      F0 --> F63
         *      FSR
         *      GSR
         *      FPRS
         */
        [REGSET_FP] = {
                .core_note_type = NT_PRFPREG,
                .n = 35,
                .size = sizeof(u64), .align = sizeof(u64),
                .regset_get = fpregs64_get, .set = fpregs64_set
        },
};

static int getregs64_get(struct task_struct *target,
                         const struct user_regset *regset,
                         struct membuf to)
{
        const struct pt_regs *regs = task_pt_regs(target);

        if (target == current)
                flushw_user();

        membuf_write(&to, regs->u_regs + 1, 15 * sizeof(u64));
        membuf_store(&to, (u64)0);
        membuf_write(&to, &regs->tstate, 3 * sizeof(u64));
        return membuf_store(&to, (u64)regs->y);
}

static int setregs64_set(struct task_struct *target,
                         const struct user_regset *regset,
                         unsigned int pos, unsigned int count,
                         const void *kbuf, const void __user *ubuf)
{
        struct pt_regs *regs = task_pt_regs(target);
        unsigned long y = regs->y;
        unsigned long tstate;
        int ret;

        if (target == current)
                flushw_user();

        ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                 regs->u_regs + 1,
                                 0 * sizeof(u64),
                                 15 * sizeof(u64));
        if (ret)
                return ret;
        ret =user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
                                 15 * sizeof(u64), 16 * sizeof(u64));
        if (ret)
                return ret;
        /* TSTATE */
        ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                 &tstate,
                                 16 * sizeof(u64),
                                 17 * sizeof(u64));
        if (ret)
                return ret;
        /* Only the condition codes and the "in syscall"
         * state can be modified in the %tstate register.
         */
        tstate &= (TSTATE_ICC | TSTATE_XCC | TSTATE_SYSCALL);
        regs->tstate &= ~(TSTATE_ICC | TSTATE_XCC | TSTATE_SYSCALL);
        regs->tstate |= tstate;

        /* TPC, TNPC */
        ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                 &regs->tpc,
                                 17 * sizeof(u64),
                                 19 * sizeof(u64));
        if (ret)
                return ret;
        /* Y */
        ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                 &y,
                                 19 * sizeof(u64),
                                 20 * sizeof(u64));
        if (!ret)
                regs->y = y;
        return ret;
}

static const struct user_regset ptrace64_regsets[] = {
        /* Format is:
         *      G1 --> G7
         *      O0 --> O7
         *      0
         *      TSTATE, TPC, TNPC, Y
         */
        [REGSET_GENERAL] = {
                .n = 20, .size = sizeof(u64),
                .regset_get = getregs64_get, .set = setregs64_set,
        },
};

static const struct user_regset_view ptrace64_view = {
        .regsets = ptrace64_regsets, .n = ARRAY_SIZE(ptrace64_regsets)
};

static const struct user_regset_view user_sparc64_view = {
        .name = "sparc64", .e_machine = EM_SPARCV9,
        .regsets = sparc64_regsets, .n = ARRAY_SIZE(sparc64_regsets)
};

#ifdef CONFIG_COMPAT
static int genregs32_get(struct task_struct *target,
                         const struct user_regset *regset,
                         struct membuf to)
{
        const struct pt_regs *regs = task_pt_regs(target);
        u32 uregs[16];
        int i;

        if (target == current)
                flushw_user();

        for (i = 0; i < 16; i++)
                membuf_store(&to, (u32)regs->u_regs[i]);
        if (!to.left)
                return 0;
        if (get_from_target(target, regs->u_regs[UREG_I6],
                            uregs, sizeof(uregs)))
                return -EFAULT;
        membuf_write(&to, uregs, 16 * sizeof(u32));
        membuf_store(&to, (u32)tstate_to_psr(regs->tstate));
        membuf_store(&to, (u32)(regs->tpc));
        membuf_store(&to, (u32)(regs->tnpc));
        membuf_store(&to, (u32)(regs->y));
        return membuf_zero(&to, 2 * sizeof(u32));
}

static int genregs32_set(struct task_struct *target,
                         const struct user_regset *regset,
                         unsigned int pos, unsigned int count,
                         const void *kbuf, const void __user *ubuf)
{
        struct pt_regs *regs = task_pt_regs(target);
        compat_ulong_t __user *reg_window;
        const compat_ulong_t *k = kbuf;
        const compat_ulong_t __user *u = ubuf;
        compat_ulong_t reg;

        if (target == current)
                flushw_user();

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

        if (kbuf) {
                for (; count > 0 && pos < 16; count--)
                        regs->u_regs[pos++] = *k++;

                reg_window = (compat_ulong_t __user *) regs->u_regs[UREG_I6];
                reg_window -= 16;
                if (target == current) {
                        for (; count > 0 && pos < 32; count--) {
                                if (put_user(*k++, &reg_window[pos++]))
                                        return -EFAULT;
                        }
                } else {
                        for (; count > 0 && pos < 32; count--) {
                                if (access_process_vm(target,
                                                      (unsigned long)
                                                      &reg_window[pos],
                                                      (void *) k,
                                                      sizeof(*k),
                                                      FOLL_FORCE | FOLL_WRITE)
                                    != sizeof(*k))
                                        return -EFAULT;
                                k++;
                                pos++;
                        }
                }
        } else {
                for (; count > 0 && pos < 16; count--) {
                        if (get_user(reg, u++))
                                return -EFAULT;
                        regs->u_regs[pos++] = reg;
                }

                reg_window = (compat_ulong_t __user *) regs->u_regs[UREG_I6];
                reg_window -= 16;
                if (target == current) {
                        for (; count > 0 && pos < 32; count--) {
                                if (get_user(reg, u++) ||
                                    put_user(reg, &reg_window[pos++]))
                                        return -EFAULT;
                        }
                } else {
                        for (; count > 0 && pos < 32; count--) {
                                if (get_user(reg, u++))
                                        return -EFAULT;
                                if (access_process_vm(target,
                                                      (unsigned long)
                                                      &reg_window[pos],
                                                      &reg, sizeof(reg),
                                                      FOLL_FORCE | FOLL_WRITE)
                                    != sizeof(reg))
                                        return -EFAULT;
                                pos++;
                                u++;
                        }
                }
        }
        while (count > 0) {
                unsigned long tstate;

                if (kbuf)
                        reg = *k++;
                else if (get_user(reg, u++))
                        return -EFAULT;

                switch (pos) {
                case 32: /* PSR */
                        tstate = regs->tstate;
                        tstate &= ~(TSTATE_ICC | TSTATE_XCC | TSTATE_SYSCALL);
                        tstate |= psr_to_tstate_icc(reg);
                        if (reg & PSR_SYSCALL)
                                tstate |= TSTATE_SYSCALL;
                        regs->tstate = tstate;
                        break;
                case 33: /* PC */
                        regs->tpc = reg;
                        break;
                case 34: /* NPC */
                        regs->tnpc = reg;
                        break;
                case 35: /* Y */
                        regs->y = reg;
                        break;
                case 36: /* WIM */
                case 37: /* TBR */
                        break;
                default:
                        goto finish;
                }

                pos++;
                count--;
        }
finish:
        pos *= sizeof(reg);
        count *= sizeof(reg);

        return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
                                         38 * sizeof(reg), -1);
}

static int fpregs32_get(struct task_struct *target,
                        const struct user_regset *regset,
                        struct membuf to)
{
        struct thread_info *t = task_thread_info(target);
        bool enabled;

        if (target == current)
                save_and_clear_fpu();

        enabled = t->fpsaved[0] & FPRS_FEF;

        membuf_write(&to, t->fpregs, 32 * sizeof(u32));
        membuf_zero(&to, sizeof(u32));
        if (enabled)
                membuf_store(&to, (u32)t->xfsr[0]);
        else
                membuf_zero(&to, sizeof(u32));
        membuf_store(&to, (u32)((enabled << 8) | (8 << 16)));
        return membuf_zero(&to, 64 * sizeof(u32));
}

static int fpregs32_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 *fpregs = task_thread_info(target)->fpregs;
        unsigned long fprs;
        int ret;

        if (target == current)
                save_and_clear_fpu();

        fprs = task_thread_info(target)->fpsaved[0];

        ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                 fpregs,
                                 0, 32 * sizeof(u32));
        if (!ret)
                user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
                                          32 * sizeof(u32),
                                          33 * sizeof(u32));
        if (!ret && count > 0) {
                compat_ulong_t fsr;
                unsigned long val;

                ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                         &fsr,
                                         33 * sizeof(u32),
                                         34 * sizeof(u32));
                if (!ret) {
                        val = task_thread_info(target)->xfsr[0];
                        val &= 0xffffffff00000000UL;
                        val |= fsr;
                        task_thread_info(target)->xfsr[0] = val;
                }
        }

        fprs |= (FPRS_FEF | FPRS_DL);
        task_thread_info(target)->fpsaved[0] = fprs;

        if (!ret)
                ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
                                                34 * sizeof(u32), -1);
        return ret;
}

static const struct user_regset sparc32_regsets[] = {
        /* Format is:
         *      G0 --> G7
         *      O0 --> O7
         *      L0 --> L7
         *      I0 --> I7
         *      PSR, PC, nPC, Y, WIM, TBR
         */
        [REGSET_GENERAL] = {
                .core_note_type = NT_PRSTATUS,
                .n = 38,
                .size = sizeof(u32), .align = sizeof(u32),
                .regset_get = genregs32_get, .set = genregs32_set
        },
        /* Format is:
         *      F0 --> F31
         *      empty 32-bit word
         *      FSR (32--bit word)
         *      FPU QUEUE COUNT (8-bit char)
         *      FPU QUEUE ENTRYSIZE (8-bit char)
         *      FPU ENABLED (8-bit char)
         *      empty 8-bit char
         *      FPU QUEUE (64 32-bit ints)
         */
        [REGSET_FP] = {
                .core_note_type = NT_PRFPREG,
                .n = 99,
                .size = sizeof(u32), .align = sizeof(u32),
                .regset_get = fpregs32_get, .set = fpregs32_set
        },
};

static int getregs_get(struct task_struct *target,
                         const struct user_regset *regset,
                         struct membuf to)
{
        const struct pt_regs *regs = task_pt_regs(target);
        int i;

        if (target == current)
                flushw_user();

        membuf_store(&to, (u32)tstate_to_psr(regs->tstate));
        membuf_store(&to, (u32)(regs->tpc));
        membuf_store(&to, (u32)(regs->tnpc));
        membuf_store(&to, (u32)(regs->y));
        for (i = 1; i < 16; i++)
                membuf_store(&to, (u32)regs->u_regs[i]);
        return to.left;
}

static int setregs_set(struct task_struct *target,
                         const struct user_regset *regset,
                         unsigned int pos, unsigned int count,
                         const void *kbuf, const void __user *ubuf)
{
        struct pt_regs *regs = task_pt_regs(target);
        unsigned long tstate;
        u32 uregs[19];
        int i, ret;

        if (target == current)
                flushw_user();

        ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                 uregs,
                                 0, 19 * sizeof(u32));
        if (ret)
                return ret;

        tstate = regs->tstate;
        tstate &= ~(TSTATE_ICC | TSTATE_XCC | TSTATE_SYSCALL);
        tstate |= psr_to_tstate_icc(uregs[0]);
        if (uregs[0] & PSR_SYSCALL)
                tstate |= TSTATE_SYSCALL;
        regs->tstate = tstate;
        regs->tpc = uregs[1];
        regs->tnpc = uregs[2];
        regs->y = uregs[3];

        for (i = 1; i < 15; i++)
                regs->u_regs[i] = uregs[3 + i];
        return 0;
}

static int getfpregs_get(struct task_struct *target,
                        const struct user_regset *regset,
                        struct membuf to)
{
        struct thread_info *t = task_thread_info(target);

        if (target == current)
                save_and_clear_fpu();

        membuf_write(&to, t->fpregs, 32 * sizeof(u32));
        if (t->fpsaved[0] & FPRS_FEF)
                membuf_store(&to, (u32)t->xfsr[0]);
        else
                membuf_zero(&to, sizeof(u32));
        return membuf_zero(&to, 35 * sizeof(u32));
}

static int setfpregs_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 *fpregs = task_thread_info(target)->fpregs;
        unsigned long fprs;
        int ret;

        if (target == current)
                save_and_clear_fpu();

        fprs = task_thread_info(target)->fpsaved[0];

        ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                 fpregs,
                                 0, 32 * sizeof(u32));
        if (!ret) {
                compat_ulong_t fsr;
                unsigned long val;

                ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                         &fsr,
                                         32 * sizeof(u32),
                                         33 * sizeof(u32));
                if (!ret) {
                        val = task_thread_info(target)->xfsr[0];
                        val &= 0xffffffff00000000UL;
                        val |= fsr;
                        task_thread_info(target)->xfsr[0] = val;
                }
        }

        fprs |= (FPRS_FEF | FPRS_DL);
        task_thread_info(target)->fpsaved[0] = fprs;
        return ret;
}

static const struct user_regset ptrace32_regsets[] = {
        [REGSET_GENERAL] = {
                .n = 19, .size = sizeof(u32),
                .regset_get = getregs_get, .set = setregs_set,
        },
        [REGSET_FP] = {
                .n = 68, .size = sizeof(u32),
                .regset_get = getfpregs_get, .set = setfpregs_set,
        },
};

static const struct user_regset_view ptrace32_view = {
        .regsets = ptrace32_regsets, .n = ARRAY_SIZE(ptrace32_regsets)
};

static const struct user_regset_view user_sparc32_view = {
        .name = "sparc", .e_machine = EM_SPARC,
        .regsets = sparc32_regsets, .n = ARRAY_SIZE(sparc32_regsets)
};
#endif /* CONFIG_COMPAT */

const struct user_regset_view *task_user_regset_view(struct task_struct *task)
{
#ifdef CONFIG_COMPAT
        if (test_tsk_thread_flag(task, TIF_32BIT))
                return &user_sparc32_view;
#endif
        return &user_sparc64_view;
}

#ifdef CONFIG_COMPAT
struct compat_fps {
        unsigned int regs[32];
        unsigned int fsr;
        unsigned int flags;
        unsigned int extra;
        unsigned int fpqd;
        struct compat_fq {
                unsigned int insnaddr;
                unsigned int insn;
        } fpq[16];
};

long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
                        compat_ulong_t caddr, compat_ulong_t cdata)
{
        compat_ulong_t caddr2 = task_pt_regs(current)->u_regs[UREG_I4];
        struct pt_regs32 __user *pregs;
        struct compat_fps __user *fps;
        unsigned long addr2 = caddr2;
        unsigned long addr = caddr;
        unsigned long data = cdata;
        int ret;

        pregs = (struct pt_regs32 __user *) addr;
        fps = (struct compat_fps __user *) addr;

        switch (request) {
        case PTRACE_PEEKUSR:
                ret = (addr != 0) ? -EIO : 0;
                break;

        case PTRACE_GETREGS:
                ret = copy_regset_to_user(child, &ptrace32_view,
                                          REGSET_GENERAL, 0,
                                          19 * sizeof(u32),
                                          pregs);
                break;

        case PTRACE_SETREGS:
                ret = copy_regset_from_user(child, &ptrace32_view,
                                          REGSET_GENERAL, 0,
                                          19 * sizeof(u32),
                                          pregs);
                break;

        case PTRACE_GETFPREGS:
                ret = copy_regset_to_user(child, &ptrace32_view,
                                          REGSET_FP, 0,
                                          68 * sizeof(u32),
                                          fps);
                break;

        case PTRACE_SETFPREGS:
                ret = copy_regset_from_user(child, &ptrace32_view,
                                          REGSET_FP, 0,
                                          33 * sizeof(u32),
                                          fps);
                break;

        case PTRACE_READTEXT:
        case PTRACE_READDATA:
                ret = ptrace_readdata(child, addr,
                                      (char __user *)addr2, data);
                if (ret == data)
                        ret = 0;
                else if (ret >= 0)
                        ret = -EIO;
                break;

        case PTRACE_WRITETEXT:
        case PTRACE_WRITEDATA:
                ret = ptrace_writedata(child, (char __user *) addr2,
                                       addr, data);
                if (ret == data)
                        ret = 0;
                else if (ret >= 0)
                        ret = -EIO;
                break;

        default:
                if (request == PTRACE_SPARC_DETACH)
                        request = PTRACE_DETACH;
                ret = compat_ptrace_request(child, request, addr, data);
                break;
        }

        return ret;
}
#endif /* CONFIG_COMPAT */

struct fps {
        unsigned int regs[64];
        unsigned long fsr;
};

long arch_ptrace(struct task_struct *child, long request,
                 unsigned long addr, unsigned long data)
{
        const struct user_regset_view *view = task_user_regset_view(current);
        unsigned long addr2 = task_pt_regs(current)->u_regs[UREG_I4];
        struct pt_regs __user *pregs;
        struct fps __user *fps;
        void __user *addr2p;
        int ret;

        pregs = (struct pt_regs __user *) addr;
        fps = (struct fps __user *) addr;
        addr2p = (void __user *) addr2;

        switch (request) {
        case PTRACE_PEEKUSR:
                ret = (addr != 0) ? -EIO : 0;
                break;

        case PTRACE_GETREGS64:
                ret = copy_regset_to_user(child, &ptrace64_view,
                                          REGSET_GENERAL, 0,
                                          19 * sizeof(u64),
                                          pregs);
                break;

        case PTRACE_SETREGS64:
                ret = copy_regset_from_user(child, &ptrace64_view,
                                          REGSET_GENERAL, 0,
                                          19 * sizeof(u64),
                                          pregs);
                break;

        case PTRACE_GETFPREGS64:
                ret = copy_regset_to_user(child, view, REGSET_FP,
                                          0 * sizeof(u64),
                                          33 * sizeof(u64),
                                          fps);
                break;

        case PTRACE_SETFPREGS64:
                ret = copy_regset_from_user(child, view, REGSET_FP,
                                          0 * sizeof(u64),
                                          33 * sizeof(u64),
                                          fps);
                break;

        case PTRACE_READTEXT:
        case PTRACE_READDATA:
                ret = ptrace_readdata(child, addr, addr2p, data);
                if (ret == data)
                        ret = 0;
                else if (ret >= 0)
                        ret = -EIO;
                break;

        case PTRACE_WRITETEXT:
        case PTRACE_WRITEDATA:
                ret = ptrace_writedata(child, addr2p, addr, data);
                if (ret == data)
                        ret = 0;
                else if (ret >= 0)
                        ret = -EIO;
                break;

        default:
                if (request == PTRACE_SPARC_DETACH)
                        request = PTRACE_DETACH;
                ret = ptrace_request(child, request, addr, data);
                break;
        }

        return ret;
}

asmlinkage int syscall_trace_enter(struct pt_regs *regs)
{
        int ret = 0;

        /* do the secure computing check first */
        secure_computing_strict(regs->u_regs[UREG_G1]);

        if (test_thread_flag(TIF_NOHZ))
                user_exit();

        if (test_thread_flag(TIF_SYSCALL_TRACE))
                ret = ptrace_report_syscall_entry(regs);

        if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
                trace_sys_enter(regs, regs->u_regs[UREG_G1]);

        audit_syscall_entry(regs->u_regs[UREG_G1], regs->u_regs[UREG_I0],
                            regs->u_regs[UREG_I1], regs->u_regs[UREG_I2],
                            regs->u_regs[UREG_I3]);

        return ret;
}

asmlinkage void syscall_trace_leave(struct pt_regs *regs)
{
        if (test_thread_flag(TIF_NOHZ))
                user_exit();

        audit_syscall_exit(regs);

        if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
                trace_sys_exit(regs, regs->u_regs[UREG_I0]);

        if (test_thread_flag(TIF_SYSCALL_TRACE))
                ptrace_report_syscall_exit(regs, 0);

        if (test_thread_flag(TIF_NOHZ))
                user_enter();
}

/**
 * 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_within_kernel_stack() - check the address in the stack
 * @regs:       pt_regs which contains kernel stack pointer.
 * @addr:       address which is checked.
 *
 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
 * If @addr is within the kernel stack, it returns true. If not, returns false.
 */
static inline int regs_within_kernel_stack(struct pt_regs *regs,
                                           unsigned long addr)
{
        unsigned long ksp = kernel_stack_pointer(regs) + STACK_BIAS;
        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 specified 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 ksp = kernel_stack_pointer(regs) + STACK_BIAS;
        unsigned long *addr = (unsigned long *)ksp;
        addr += n;
        if (regs_within_kernel_stack(regs, (unsigned long)addr))
                return *addr;
        else
                return 0;
}