/* SPDX-License-Identifier: GPL-2.0 */
/*

 * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
 * Copyright (C) 2005 Jeff Dike (jdike@karaya.com)
 */

#ifndef __STUB_DATA_H
#define __STUB_DATA_H

#include <linux/compiler_types.h>
#include <as-layout.h>
#include <sysdep/tls.h>
#include <sysdep/stub-data.h>
#include <mm_id.h>

#define FUTEX_IN_CHILD 0
#define FUTEX_IN_KERN 1

struct stub_init_data {
        int seccomp;

        unsigned long stub_start;

        int stub_code_fd;
        unsigned long stub_code_offset;
        int stub_data_fd;
        unsigned long stub_data_offset;

        unsigned long signal_handler;
        unsigned long signal_restorer;
};

#define STUB_NEXT_SYSCALL(s) \
        ((struct stub_syscall *) (((unsigned long) s) + (s)->cmd_len))

enum stub_syscall_type {
        STUB_SYSCALL_UNSET = 0,
        STUB_SYSCALL_MMAP,
        STUB_SYSCALL_MUNMAP,
};

struct stub_syscall {
        struct {
                unsigned long addr;
                unsigned long length;
                unsigned long offset;
                int fd;
                int prot;
        } mem;

        enum stub_syscall_type syscall;
};

struct stub_data {
        long err;

        int syscall_data_len;
        /* 128 leaves enough room for additional fields in the struct */
        struct stub_syscall syscall_data[(UM_KERN_PAGE_SIZE - 128) / sizeof(struct stub_syscall)] __aligned(16);

        /* data shared with signal handler (only used in seccomp mode) */
        short restart_wait;
        unsigned int futex;
        int signal;
        unsigned short si_offset;
        unsigned short mctx_offset;

        /* seccomp architecture specific state restore */
        struct stub_data_arch arch_data;

        /* Stack for our signal handlers and for calling into . */
        unsigned char sigstack[UM_KERN_PAGE_SIZE] __aligned(UM_KERN_PAGE_SIZE);
};

#endif