root/arch/powerpc/kernel/sys_ppc32.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * sys_ppc32.c: 32-bit system calls with complex calling conventions.
 *
 * Copyright (C) 2001 IBM
 * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
 * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
 *
 * 32-bit system calls with 64-bit arguments pass those in register pairs.
 * This must be specially dealt with on 64-bit kernels. The compat_arg_u64_dual
 * in generic compat syscalls is not always usable because the register
 * pairing is constrained depending on preceding arguments.
 *
 * An analogous problem exists on 32-bit kernels with ARCH_HAS_SYSCALL_WRAPPER,
 * the defined system call functions take the pt_regs as an argument, and there
 * is a mapping macro which maps registers to arguments
 * (SC_POWERPC_REGS_TO_ARGS) which also does not deal with these 64-bit
 * arguments.
 *
 * This file contains these system calls.
 */

#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/fs.h> 
#include <linux/mm.h> 
#include <linux/file.h> 
#include <linux/signal.h>
#include <linux/resource.h>
#include <linux/times.h>
#include <linux/smp.h>
#include <linux/sem.h>
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/poll.h>
#include <linux/personality.h>
#include <linux/stat.h>
#include <linux/in.h>
#include <linux/syscalls.h>
#include <linux/unistd.h>
#include <linux/sysctl.h>
#include <linux/binfmts.h>
#include <linux/security.h>
#include <linux/compat.h>
#include <linux/ptrace.h>
#include <linux/elf.h>
#include <linux/ipc.h>
#include <linux/slab.h>

#include <asm/ptrace.h>
#include <asm/types.h>
#include <linux/uaccess.h>
#include <asm/unistd.h>
#include <asm/time.h>
#include <asm/mmu_context.h>
#include <asm/ppc-pci.h>
#include <asm/syscalls.h>
#include <asm/switch_to.h>

#ifdef CONFIG_PPC32
#define PPC32_SYSCALL_DEFINE4   SYSCALL_DEFINE4
#define PPC32_SYSCALL_DEFINE5   SYSCALL_DEFINE5
#define PPC32_SYSCALL_DEFINE6   SYSCALL_DEFINE6
#else
#define PPC32_SYSCALL_DEFINE4   COMPAT_SYSCALL_DEFINE4
#define PPC32_SYSCALL_DEFINE5   COMPAT_SYSCALL_DEFINE5
#define PPC32_SYSCALL_DEFINE6   COMPAT_SYSCALL_DEFINE6
#endif

PPC32_SYSCALL_DEFINE6(ppc_pread64,
                       unsigned int, fd,
                       char __user *, ubuf, compat_size_t, count,
                       u32, reg6, u32, pos1, u32, pos2)
{
        return ksys_pread64(fd, ubuf, count, merge_64(pos1, pos2));
}

PPC32_SYSCALL_DEFINE6(ppc_pwrite64,
                       unsigned int, fd,
                       const char __user *, ubuf, compat_size_t, count,
                       u32, reg6, u32, pos1, u32, pos2)
{
        return ksys_pwrite64(fd, ubuf, count, merge_64(pos1, pos2));
}

PPC32_SYSCALL_DEFINE5(ppc_readahead,
                       int, fd, u32, r4,
                       u32, offset1, u32, offset2, u32, count)
{
        return ksys_readahead(fd, merge_64(offset1, offset2), count);
}

PPC32_SYSCALL_DEFINE4(ppc_truncate64,
                       const char __user *, path, u32, reg4,
                       unsigned long, len1, unsigned long, len2)
{
        return ksys_truncate(path, merge_64(len1, len2));
}

PPC32_SYSCALL_DEFINE4(ppc_ftruncate64,
                       unsigned int, fd, u32, reg4,
                       unsigned long, len1, unsigned long, len2)
{
        return ksys_ftruncate(fd, merge_64(len1, len2));
}

PPC32_SYSCALL_DEFINE6(ppc32_fadvise64,
                       int, fd, u32, unused, u32, offset1, u32, offset2,
                       size_t, len, int, advice)
{
        return ksys_fadvise64_64(fd, merge_64(offset1, offset2), len,
                                 advice);
}

PPC32_SYSCALL_DEFINE6(ppc_sync_file_range2,
                       int, fd, unsigned int, flags,
                       unsigned int, offset1, unsigned int, offset2,
                       unsigned int, nbytes1, unsigned int, nbytes2)
{
        loff_t offset = merge_64(offset1, offset2);
        loff_t nbytes = merge_64(nbytes1, nbytes2);

        return ksys_sync_file_range(fd, offset, nbytes, flags);
}

#ifdef CONFIG_PPC32
SYSCALL_DEFINE6(ppc_fallocate,
                int, fd, int, mode,
                u32, offset1, u32, offset2, u32, len1, u32, len2)
{
        return ksys_fallocate(fd, mode,
                              merge_64(offset1, offset2),
                              merge_64(len1, len2));
}
#endif