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

#include <linux/module.h>
#include <linux/ptrace.h>
#include <linux/sched.h>
#include <linux/ftrace.h>
#include <asm/siginfo.h>
#include <asm/signal.h>
#include <asm/unistd.h>
#include <frame_kern.h>
#include <kern_util.h>
#include <os.h>

EXPORT_SYMBOL(block_signals);
EXPORT_SYMBOL(unblock_signals);

void block_signals_trace(void)
{
        block_signals();
        if (current_thread_info())
                trace_hardirqs_off();
}

void unblock_signals_trace(void)
{
        if (current_thread_info())
                trace_hardirqs_on();
        unblock_signals();
}

void um_trace_signals_on(void)
{
        if (current_thread_info())
                trace_hardirqs_on();
}

void um_trace_signals_off(void)
{
        if (current_thread_info())
                trace_hardirqs_off();
}

/*
 * OK, we're invoking a handler
 */
static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
{
        sigset_t *oldset = sigmask_to_save();
        int singlestep = 0;
        unsigned long sp;
        int err;

        if (test_thread_flag(TIF_SINGLESTEP) && (current->ptrace & PT_PTRACED))
                singlestep = 1;

        /* Did we come from a system call? */
        if (PT_REGS_SYSCALL_NR(regs) >= 0) {
                /* If so, check system call restarting.. */
                switch (PT_REGS_SYSCALL_RET(regs)) {
                case -ERESTART_RESTARTBLOCK:
                case -ERESTARTNOHAND:
                        PT_REGS_SYSCALL_RET(regs) = -EINTR;
                        break;

                case -ERESTARTSYS:
                        if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
                                PT_REGS_SYSCALL_RET(regs) = -EINTR;
                                break;
                        }
                        fallthrough;
                case -ERESTARTNOINTR:
                        PT_REGS_RESTART_SYSCALL(regs);
                        PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
                        break;
                }
        }

        sp = PT_REGS_SP(regs);
        if ((ksig->ka.sa.sa_flags & SA_ONSTACK) && (sas_ss_flags(sp) == 0))
                sp = current->sas_ss_sp + current->sas_ss_size;

#ifdef CONFIG_ARCH_HAS_SC_SIGNALS
        if (!(ksig->ka.sa.sa_flags & SA_SIGINFO))
                err = setup_signal_stack_sc(sp, ksig, regs, oldset);
        else
#endif
                err = setup_signal_stack_si(sp, ksig, regs, oldset);

        signal_setup_done(err, ksig, singlestep);
}

void do_signal(struct pt_regs *regs)
{
        struct ksignal ksig;
        int handled_sig = 0;

        while (get_signal(&ksig)) {
                handled_sig = 1;
                /* Whee!  Actually deliver the signal.  */
                handle_signal(&ksig, regs);
        }

        /* Did we come from a system call? */
        if (!handled_sig && (PT_REGS_SYSCALL_NR(regs) >= 0)) {
                /* Restart the system call - no handlers present */
                switch (PT_REGS_SYSCALL_RET(regs)) {
                case -ERESTARTNOHAND:
                case -ERESTARTSYS:
                case -ERESTARTNOINTR:
                        PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
                        PT_REGS_RESTART_SYSCALL(regs);
                        break;
                case -ERESTART_RESTARTBLOCK:
                        PT_REGS_ORIG_SYSCALL(regs) = __NR_restart_syscall;
                        PT_REGS_RESTART_SYSCALL(regs);
                        break;
                }
        }

        /*
         * if there's no signal to deliver, we just put the saved sigmask
         * back
         */
        if (!handled_sig)
                restore_saved_sigmask();
}