// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
 */

#include <linux/audit.h>
#include <linux/ptrace.h>
#include <linux/sched.h>
#include <linux/uaccess.h>
#include <asm/ptrace-abi.h>

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

void user_enable_single_step(struct task_struct *child)
{
        set_tsk_thread_flag(child, TIF_SINGLESTEP);

#ifdef SUBARCH_SET_SINGLESTEPPING
        SUBARCH_SET_SINGLESTEPPING(child, 1);
#endif
}

void user_disable_single_step(struct task_struct *child)
{
        clear_tsk_thread_flag(child, TIF_SINGLESTEP);

#ifdef SUBARCH_SET_SINGLESTEPPING
        SUBARCH_SET_SINGLESTEPPING(child, 0);
#endif
}

/*
 * Called by kernel/ptrace.c when detaching..
 */
void ptrace_disable(struct task_struct *child)
{
        user_disable_single_step(child);
}

long arch_ptrace(struct task_struct *child, long request,
                 unsigned long addr, unsigned long data)
{
        int i, ret;
        unsigned long __user *p = (void __user *)data;
        void __user *vp = p;

        switch (request) {
        /* read the word at location addr in the USER area. */
        case PTRACE_PEEKUSR:
                ret = peek_user(child, addr, data);
                break;

        /* write the word at location addr in the USER area */
        case PTRACE_POKEUSR:
                ret = poke_user(child, addr, data);
                break;

        case PTRACE_SYSEMU:
        case PTRACE_SYSEMU_SINGLESTEP:
                ret = -EIO;
                break;

#ifdef PTRACE_GETREGS
        case PTRACE_GETREGS: { /* Get all gp regs from the child. */
                if (!access_ok(p, MAX_REG_OFFSET)) {
                        ret = -EIO;
                        break;
                }
                for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) {
                        __put_user(getreg(child, i), p);
                        p++;
                }
                ret = 0;
                break;
        }
#endif
#ifdef PTRACE_SETREGS
        case PTRACE_SETREGS: { /* Set all gp regs in the child. */
                unsigned long tmp = 0;
                if (!access_ok(p, MAX_REG_OFFSET)) {
                        ret = -EIO;
                        break;
                }
                for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) {
                        __get_user(tmp, p);
                        putreg(child, i, tmp);
                        p++;
                }
                ret = 0;
                break;
        }
#endif
        case PTRACE_GET_THREAD_AREA:
                ret = ptrace_get_thread_area(child, addr, vp);
                break;

        case PTRACE_SET_THREAD_AREA:
                ret = ptrace_set_thread_area(child, addr, vp);
                break;

        default:
                ret = ptrace_request(child, request, addr, data);
                if (ret == -EIO)
                        ret = subarch_ptrace(child, request, addr, data);
                break;
        }

        return ret;
}

static void send_sigtrap(struct uml_pt_regs *regs, int error_code)
{
        /* Send us the fake SIGTRAP */
        force_sig_fault(SIGTRAP, TRAP_BRKPT,
                        /* User-mode eip? */
                        UPT_IS_USER(regs) ? (void __user *) UPT_IP(regs) : NULL);
}

/*
 * XXX Check TIF_SINGLESTEP for singlestepping check and
 * PT_PTRACED vs TIF_SYSCALL_TRACE for syscall tracing check
 */
int syscall_trace_enter(struct pt_regs *regs)
{
        audit_syscall_entry(UPT_SYSCALL_NR(&regs->regs),
                            UPT_SYSCALL_ARG1(&regs->regs),
                            UPT_SYSCALL_ARG2(&regs->regs),
                            UPT_SYSCALL_ARG3(&regs->regs),
                            UPT_SYSCALL_ARG4(&regs->regs));

        if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
                trace_sys_enter(regs, UPT_SYSCALL_NR(&regs->regs));

        if (!test_thread_flag(TIF_SYSCALL_TRACE))
                return 0;

        return ptrace_report_syscall_entry(regs);
}

void syscall_trace_leave(struct pt_regs *regs)
{
        int ptraced = current->ptrace;

        audit_syscall_exit(regs);

        /* Fake a debug trap */
        if (test_thread_flag(TIF_SINGLESTEP))
                send_sigtrap(&regs->regs, 0);

        if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
                trace_sys_exit(regs, PT_REGS_SYSCALL_RET(regs));

        if (!test_thread_flag(TIF_SYSCALL_TRACE))
                return;

        ptrace_report_syscall_exit(regs, 0);
        /* force do_signal() --> is_syscall() */
        if (ptraced & PT_PTRACED)
                set_thread_flag(TIF_SIGPENDING);
}