/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1992 Ross Biro
 * Copyright (C) Linus Torvalds
 * Copyright (C) 1994, 95, 96, 97, 98, 2000 Ralf Baechle
 * Copyright (C) 1996 David S. Miller
 * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
 * Copyright (C) 1999 MIPS Technologies, Inc.
 * Copyright (C) 2000 Ulf Carlsson
 *
 * At this time Linux/MIPS64 only supports syscall tracing, even for 32-bit
 * binaries.
 */
#include <linux/compiler.h>
#include <linux/compat.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/smp.h>
#include <linux/security.h>

#include <asm/cpu.h>
#include <asm/dsp.h>
#include <asm/fpu.h>
#include <asm/mipsregs.h>
#include <asm/mipsmtregs.h>
#include <asm/page.h>
#include <asm/reg.h>
#include <asm/syscall.h>
#include <linux/uaccess.h>
#include <asm/bootinfo.h>

/*
 * Tracing a 32-bit process with a 64-bit strace and vice versa will not
 * work.  I don't know how to fix this.
 */
long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
                        compat_ulong_t caddr, compat_ulong_t cdata)
{
        int addr = caddr;
        int data = cdata;
        int ret;

        switch (request) {

        /*
         * Read 4 bytes of the other process' storage
         *  data is a pointer specifying where the user wants the
         *      4 bytes copied into
         *  addr is a pointer in the user's storage that contains an 8 byte
         *      address in the other process of the 4 bytes that is to be read
         * (this is run in a 32-bit process looking at a 64-bit process)
         * when I and D space are separate, these will need to be fixed.
         */
        case PTRACE_PEEKTEXT_3264:
        case PTRACE_PEEKDATA_3264: {
                u32 tmp;
                int copied;
                u32 __user * addrOthers;

                ret = -EIO;

                /* Get the addr in the other process that we want to read */
                if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
                        break;

                copied = ptrace_access_vm(child, (u64)addrOthers, &tmp,
                                sizeof(tmp), FOLL_FORCE);
                if (copied != sizeof(tmp))
                        break;
                ret = put_user(tmp, (u32 __user *) (unsigned long) data);
                break;
        }

        /* Read the word at location addr in the USER area. */
        case PTRACE_PEEKUSR: {
                struct pt_regs *regs;
                unsigned int tmp;

                regs = task_pt_regs(child);
                ret = 0;  /* Default return value. */

                switch (addr) {
                case 0 ... 31:
                        tmp = regs->regs[addr];
                        break;
#ifdef CONFIG_MIPS_FP_SUPPORT
                case FPR_BASE ... FPR_BASE + 31: {
                        union fpureg *fregs;

                        if (!tsk_used_math(child)) {
                                /* FP not yet used */
                                tmp = -1;
                                break;
                        }
                        fregs = get_fpu_regs(child);
                        if (test_tsk_thread_flag(child, TIF_32BIT_FPREGS)) {
                                /*
                                 * The odd registers are actually the high
                                 * order bits of the values stored in the even
                                 * registers.
                                 */
                                tmp = get_fpr32(&fregs[(addr & ~1) - FPR_BASE],
                                                addr & 1);
                                break;
                        }
                        tmp = get_fpr64(&fregs[addr - FPR_BASE], 0);
                        break;
                }
                case FPC_CSR:
                        tmp = child->thread.fpu.fcr31;
                        break;
                case FPC_EIR:
                        /* implementation / version register */
                        tmp = boot_cpu_data.fpu_id;
                        break;
#endif /* CONFIG_MIPS_FP_SUPPORT */
                case PC:
                        tmp = regs->cp0_epc;
                        break;
                case CAUSE:
                        tmp = regs->cp0_cause;
                        break;
                case BADVADDR:
                        tmp = regs->cp0_badvaddr;
                        break;
                case MMHI:
                        tmp = regs->hi;
                        break;
                case MMLO:
                        tmp = regs->lo;
                        break;
                case DSP_BASE ... DSP_BASE + 5: {
                        dspreg_t *dregs;

                        if (!cpu_has_dsp) {
                                tmp = 0;
                                ret = -EIO;
                                goto out;
                        }
                        dregs = __get_dsp_regs(child);
                        tmp = dregs[addr - DSP_BASE];
                        break;
                }
                case DSP_CONTROL:
                        if (!cpu_has_dsp) {
                                tmp = 0;
                                ret = -EIO;
                                goto out;
                        }
                        tmp = child->thread.dsp.dspcontrol;
                        break;
                default:
                        tmp = 0;
                        ret = -EIO;
                        goto out;
                }
                ret = put_user(tmp, (unsigned __user *) (unsigned long) data);
                break;
        }

        /*
         * Write 4 bytes into the other process' storage
         *  data is the 4 bytes that the user wants written
         *  addr is a pointer in the user's storage that contains an
         *      8 byte address in the other process where the 4 bytes
         *      that is to be written
         * (this is run in a 32-bit process looking at a 64-bit process)
         * when I and D space are separate, these will need to be fixed.
         */
        case PTRACE_POKETEXT_3264:
        case PTRACE_POKEDATA_3264: {
                u32 __user * addrOthers;

                /* Get the addr in the other process that we want to write into */
                ret = -EIO;
                if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
                        break;
                ret = 0;
                if (ptrace_access_vm(child, (u64)addrOthers, &data,
                                        sizeof(data),
                                        FOLL_FORCE | FOLL_WRITE) == sizeof(data))
                        break;
                ret = -EIO;
                break;
        }

        case PTRACE_POKEUSR: {
                struct pt_regs *regs;
                ret = 0;
                regs = task_pt_regs(child);

                switch (addr) {
                case 0 ... 31:
                        regs->regs[addr] = data;
                        /* System call number may have been changed */
                        if (addr == 2)
                                mips_syscall_update_nr(child, regs);
                        else if (addr == 4 &&
                                 mips_syscall_is_indirect(child, regs))
                                mips_syscall_update_nr(child, regs);
                        break;
#ifdef CONFIG_MIPS_FP_SUPPORT
                case FPR_BASE ... FPR_BASE + 31: {
                        union fpureg *fregs = get_fpu_regs(child);

                        if (!tsk_used_math(child)) {
                                /* FP not yet used  */
                                memset(&child->thread.fpu, ~0,
                                       sizeof(child->thread.fpu));
                                child->thread.fpu.fcr31 = 0;
                        }
                        if (test_tsk_thread_flag(child, TIF_32BIT_FPREGS)) {
                                /*
                                 * The odd registers are actually the high
                                 * order bits of the values stored in the even
                                 * registers.
                                 */
                                set_fpr32(&fregs[(addr & ~1) - FPR_BASE],
                                          addr & 1, data);
                                break;
                        }
                        set_fpr64(&fregs[addr - FPR_BASE], 0, data);
                        break;
                }
                case FPC_CSR:
                        child->thread.fpu.fcr31 = data;
                        break;
#endif /* CONFIG_MIPS_FP_SUPPORT */
                case PC:
                        regs->cp0_epc = data;
                        break;
                case MMHI:
                        regs->hi = data;
                        break;
                case MMLO:
                        regs->lo = data;
                        break;
                case DSP_BASE ... DSP_BASE + 5: {
                        dspreg_t *dregs;

                        if (!cpu_has_dsp) {
                                ret = -EIO;
                                break;
                        }

                        dregs = __get_dsp_regs(child);
                        dregs[addr - DSP_BASE] = data;
                        break;
                }
                case DSP_CONTROL:
                        if (!cpu_has_dsp) {
                                ret = -EIO;
                                break;
                        }
                        child->thread.dsp.dspcontrol = data;
                        break;
                default:
                        /* The rest are not allowed. */
                        ret = -EIO;
                        break;
                }
                break;
                }

        case PTRACE_GETREGS:
                ret = ptrace_getregs(child,
                                (struct user_pt_regs __user *) (__u64) data);
                break;

        case PTRACE_SETREGS:
                ret = ptrace_setregs(child,
                                (struct user_pt_regs __user *) (__u64) data);
                break;

#ifdef CONFIG_MIPS_FP_SUPPORT
        case PTRACE_GETFPREGS:
                ret = ptrace_getfpregs(child, (__u32 __user *) (__u64) data);
                break;

        case PTRACE_SETFPREGS:
                ret = ptrace_setfpregs(child, (__u32 __user *) (__u64) data);
                break;
#endif
        case PTRACE_GET_THREAD_AREA:
                ret = put_user(task_thread_info(child)->tp_value,
                                (unsigned int __user *) (unsigned long) data);
                break;

        case PTRACE_GET_THREAD_AREA_3264:
                ret = put_user(task_thread_info(child)->tp_value,
                                (unsigned long __user *) (unsigned long) data);
                break;

        case PTRACE_GET_WATCH_REGS:
                ret = ptrace_get_watch_regs(child,
                        (struct pt_watch_regs __user *) (unsigned long) addr);
                break;

        case PTRACE_SET_WATCH_REGS:
                ret = ptrace_set_watch_regs(child,
                        (struct pt_watch_regs __user *) (unsigned long) addr);
                break;

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