// SPDX-License-Identifier: GPL-2.0-or-later

/*
 *    PARISC specific syscalls
 *
 *    Copyright (C) 1999-2003 Matthew Wilcox <willy at parisc-linux.org>
 *    Copyright (C) 2000-2003 Paul Bame <bame at parisc-linux.org>
 *    Copyright (C) 2001 Thomas Bogendoerfer <tsbogend at parisc-linux.org>
 *    Copyright (C) 1999-2020 Helge Deller <deller@gmx.de>
 */

#include <linux/uaccess.h>
#include <asm/elf.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/linkage.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/sched/signal.h>
#include <linux/sched/mm.h>
#include <linux/shm.h>
#include <linux/syscalls.h>
#include <linux/utsname.h>
#include <linux/personality.h>
#include <linux/random.h>
#include <linux/compat.h>
#include <linux/elf-randomize.h>

/*
 * Construct an artificial page offset for the mapping based on the physical
 * address of the kernel file mapping variable.
 */
#define GET_FILP_PGOFF(filp)            \
        (filp ? (((unsigned long) filp->f_mapping) >> 8)        \
                 & ((SHM_COLOUR-1) >> PAGE_SHIFT) : 0UL)

static unsigned long shared_align_offset(unsigned long filp_pgoff,
                                         unsigned long pgoff)
{
        return (filp_pgoff + pgoff) << PAGE_SHIFT;
}

static inline unsigned long COLOR_ALIGN(unsigned long addr,
                         unsigned long filp_pgoff, unsigned long pgoff)
{
        unsigned long base = (addr+SHM_COLOUR-1) & ~(SHM_COLOUR-1);
        unsigned long off  = (SHM_COLOUR-1) &
                shared_align_offset(filp_pgoff, pgoff);
        return base + off;
}


#define STACK_SIZE_DEFAULT (USER_WIDE_MODE                      \
                        ? (1 << 30)     /* 1 GB */              \
                        : (CONFIG_STACK_MAX_DEFAULT_SIZE_MB*1024*1024))

unsigned long calc_max_stack_size(unsigned long stack_max)
{
#ifdef CONFIG_COMPAT
        if (!USER_WIDE_MODE && (stack_max == COMPAT_RLIM_INFINITY))
                stack_max = STACK_SIZE_DEFAULT;
        else
#endif
        if (stack_max == RLIM_INFINITY)
                stack_max = STACK_SIZE_DEFAULT;

        return stack_max;
}


/*
 * Top of mmap area (just below the process stack).
 */

/*
 * When called from arch_get_unmapped_area(), rlim_stack will be NULL,
 * indicating that "current" should be used instead of a passed-in
 * value from the exec bprm as done with arch_pick_mmap_layout().
 */
unsigned long mmap_upper_limit(const struct rlimit *rlim_stack)
{
        unsigned long stack_base;

        /* Limit stack size - see setup_arg_pages() in fs/exec.c */
        stack_base = rlim_stack ? rlim_stack->rlim_max
                                : rlimit_max(RLIMIT_STACK);

        stack_base = calc_max_stack_size(stack_base);

        /* Add space for stack randomization. */
        if (current->flags & PF_RANDOMIZE)
                stack_base += (STACK_RND_MASK << PAGE_SHIFT);

        return PAGE_ALIGN(STACK_TOP - stack_base);
}

enum mmap_allocation_direction {UP, DOWN};

static unsigned long arch_get_unmapped_area_common(struct file *filp,
        unsigned long addr, unsigned long len, unsigned long pgoff,
        unsigned long flags, enum mmap_allocation_direction dir)
{
        struct mm_struct *mm = current->mm;
        struct vm_area_struct *vma, *prev;
        unsigned long filp_pgoff;
        int do_color_align;
        struct vm_unmapped_area_info info = {
                .length = len
        };

        if (unlikely(len > TASK_SIZE))
                return -ENOMEM;

        do_color_align = 0;
        if (filp || (flags & MAP_SHARED))
                do_color_align = 1;
        filp_pgoff = GET_FILP_PGOFF(filp);

        if (flags & MAP_FIXED) {
                /* Even MAP_FIXED mappings must reside within TASK_SIZE */
                if (TASK_SIZE - len < addr)
                        return -EINVAL;

                if ((flags & MAP_SHARED) && filp &&
                    (addr - shared_align_offset(filp_pgoff, pgoff))
                                & (SHM_COLOUR - 1))
                        return -EINVAL;
                return addr;
        }

        if (addr) {
                if (do_color_align)
                        addr = COLOR_ALIGN(addr, filp_pgoff, pgoff);
                else
                        addr = PAGE_ALIGN(addr);

                vma = find_vma_prev(mm, addr, &prev);
                if (TASK_SIZE - len >= addr &&
                    (!vma || addr + len <= vm_start_gap(vma)) &&
                    (!prev || addr >= vm_end_gap(prev)))
                        return addr;
        }

        info.align_mask = do_color_align ? (PAGE_MASK & (SHM_COLOUR - 1)) : 0;
        info.align_offset = shared_align_offset(filp_pgoff, pgoff);

        if (dir == DOWN) {
                info.flags = VM_UNMAPPED_AREA_TOPDOWN;
                info.low_limit = PAGE_SIZE;
                info.high_limit = mm->mmap_base;
                addr = vm_unmapped_area(&info);
                if (!(addr & ~PAGE_MASK))
                        return addr;
                VM_BUG_ON(addr != -ENOMEM);

                /*
                 * A failed mmap() very likely causes application failure,
                 * so fall back to the bottom-up function here. This scenario
                 * can happen with large stack limits and large mmap()
                 * allocations.
                 */
        }

        info.low_limit = mm->mmap_base;
        info.high_limit = mmap_upper_limit(NULL);
        return vm_unmapped_area(&info);
}

unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
        unsigned long len, unsigned long pgoff, unsigned long flags,
        vm_flags_t vm_flags)
{
        return arch_get_unmapped_area_common(filp,
                        addr, len, pgoff, flags, UP);
}

unsigned long arch_get_unmapped_area_topdown(struct file *filp,
        unsigned long addr, unsigned long len, unsigned long pgoff,
        unsigned long flags, vm_flags_t vm_flags)
{
        return arch_get_unmapped_area_common(filp,
                        addr, len, pgoff, flags, DOWN);
}

asmlinkage unsigned long sys_mmap2(unsigned long addr, unsigned long len,
        unsigned long prot, unsigned long flags, unsigned long fd,
        unsigned long pgoff)
{
        /* Make sure the shift for mmap2 is constant (12), no matter what PAGE_SIZE
           we have. */
        return ksys_mmap_pgoff(addr, len, prot, flags, fd,
                               pgoff >> (PAGE_SHIFT - 12));
}

asmlinkage unsigned long sys_mmap(unsigned long addr, unsigned long len,
                unsigned long prot, unsigned long flags, unsigned long fd,
                unsigned long offset)
{
        if (!(offset & ~PAGE_MASK)) {
                return ksys_mmap_pgoff(addr, len, prot, flags, fd,
                                        offset >> PAGE_SHIFT);
        } else {
                return -EINVAL;
        }
}

/* Fucking broken ABI */

#ifdef CONFIG_64BIT
asmlinkage long parisc_truncate64(const char __user * path,
                                        unsigned int high, unsigned int low)
{
        return ksys_truncate(path, (long)high << 32 | low);
}

asmlinkage long parisc_ftruncate64(unsigned int fd,
                                        unsigned int high, unsigned int low)
{
        return ksys_ftruncate(fd, (long)high << 32 | low);
}

/* stubs for the benefit of the syscall_table since truncate64 and truncate 
 * are identical on LP64 */
asmlinkage long sys_truncate64(const char __user * path, unsigned long length)
{
        return ksys_truncate(path, length);
}
asmlinkage long sys_ftruncate64(unsigned int fd, unsigned long length)
{
        return ksys_ftruncate(fd, length);
}
asmlinkage long sys_fcntl64(unsigned int fd, unsigned int cmd, unsigned long arg)
{
        return sys_fcntl(fd, cmd, arg);
}
#else

asmlinkage long parisc_truncate64(const char __user * path,
                                        unsigned int high, unsigned int low)
{
        return ksys_truncate(path, (loff_t)high << 32 | low);
}

asmlinkage long parisc_ftruncate64(unsigned int fd,
                                        unsigned int high, unsigned int low)
{
        return sys_ftruncate64(fd, (loff_t)high << 32 | low);
}
#endif

asmlinkage ssize_t parisc_pread64(unsigned int fd, char __user *buf, size_t count,
                                        unsigned int high, unsigned int low)
{
        return ksys_pread64(fd, buf, count, (loff_t)high << 32 | low);
}

asmlinkage ssize_t parisc_pwrite64(unsigned int fd, const char __user *buf,
                        size_t count, unsigned int high, unsigned int low)
{
        return ksys_pwrite64(fd, buf, count, (loff_t)high << 32 | low);
}

asmlinkage ssize_t parisc_readahead(int fd, unsigned int high, unsigned int low,
                                    size_t count)
{
        return ksys_readahead(fd, (loff_t)high << 32 | low, count);
}

asmlinkage long parisc_fadvise64_64(int fd,
                        unsigned int high_off, unsigned int low_off,
                        unsigned int high_len, unsigned int low_len, int advice)
{
        return ksys_fadvise64_64(fd, (loff_t)high_off << 32 | low_off,
                        (loff_t)high_len << 32 | low_len, advice);
}

asmlinkage long parisc_sync_file_range(int fd,
                        u32 hi_off, u32 lo_off, u32 hi_nbytes, u32 lo_nbytes,
                        unsigned int flags)
{
        return ksys_sync_file_range(fd, (loff_t)hi_off << 32 | lo_off,
                        (loff_t)hi_nbytes << 32 | lo_nbytes, flags);
}

asmlinkage long parisc_fallocate(int fd, int mode, u32 offhi, u32 offlo,
                                u32 lenhi, u32 lenlo)
{
        return ksys_fallocate(fd, mode, ((u64)offhi << 32) | offlo,
                              ((u64)lenhi << 32) | lenlo);
}

asmlinkage long parisc_personality(unsigned long personality)
{
        long err;

        if (personality(current->personality) == PER_LINUX32
            && personality(personality) == PER_LINUX)
                personality = (personality & ~PER_MASK) | PER_LINUX32;

        err = sys_personality(personality);
        if (personality(err) == PER_LINUX32)
                err = (err & ~PER_MASK) | PER_LINUX;

        return err;
}

/*
 * Up to kernel v5.9 we defined O_NONBLOCK as 000200004,
 * since then O_NONBLOCK is defined as 000200000.
 *
 * The following wrapper functions mask out the old
 * O_NDELAY bit from calls which use O_NONBLOCK.
 *
 * XXX: Remove those in year 2022 (or later)?
 */

#define O_NONBLOCK_OLD          000200004
#define O_NONBLOCK_MASK_OUT     (O_NONBLOCK_OLD & ~O_NONBLOCK)

static int FIX_O_NONBLOCK(int flags)
{
        if ((flags & O_NONBLOCK_MASK_OUT) &&
                        !test_thread_flag(TIF_NONBLOCK_WARNING)) {
                set_thread_flag(TIF_NONBLOCK_WARNING);
                pr_warn("%s(%d) uses a deprecated O_NONBLOCK value."
                        " Please recompile with newer glibc.\n",
                        current->comm, current->pid);
        }
        return flags & ~O_NONBLOCK_MASK_OUT;
}

asmlinkage long parisc_timerfd_create(int clockid, int flags)
{
        flags = FIX_O_NONBLOCK(flags);
        return sys_timerfd_create(clockid, flags);
}

asmlinkage long parisc_signalfd4(int ufd, sigset_t __user *user_mask,
        size_t sizemask, int flags)
{
        flags = FIX_O_NONBLOCK(flags);
        return sys_signalfd4(ufd, user_mask, sizemask, flags);
}

#ifdef CONFIG_COMPAT
asmlinkage long parisc_compat_signalfd4(int ufd,
        compat_sigset_t __user *user_mask,
        compat_size_t sizemask, int flags)
{
        flags = FIX_O_NONBLOCK(flags);
        return compat_sys_signalfd4(ufd, user_mask, sizemask, flags);
}
#endif

asmlinkage long parisc_eventfd2(unsigned int count, int flags)
{
        flags = FIX_O_NONBLOCK(flags);
        return sys_eventfd2(count, flags);
}

asmlinkage long parisc_userfaultfd(int flags)
{
        flags = FIX_O_NONBLOCK(flags);
        return sys_userfaultfd(flags);
}

asmlinkage long parisc_pipe2(int __user *fildes, int flags)
{
        flags = FIX_O_NONBLOCK(flags);
        return sys_pipe2(fildes, flags);
}

asmlinkage long parisc_inotify_init1(int flags)
{
        flags = FIX_O_NONBLOCK(flags);
        return sys_inotify_init1(flags);
}

/*
 * madvise() wrapper
 *
 * Up to kernel v6.1 parisc has different values than all other
 * platforms for the MADV_xxx flags listed below.
 * To keep binary compatibility with existing userspace programs
 * translate the former values to the new values.
 *
 * XXX: Remove this wrapper in year 2025 (or later)
 */

asmlinkage notrace long parisc_madvise(unsigned long start, size_t len_in, int behavior)
{
        switch (behavior) {
        case 65: behavior = MADV_MERGEABLE;     break;
        case 66: behavior = MADV_UNMERGEABLE;   break;
        case 67: behavior = MADV_HUGEPAGE;      break;
        case 68: behavior = MADV_NOHUGEPAGE;    break;
        case 69: behavior = MADV_DONTDUMP;      break;
        case 70: behavior = MADV_DODUMP;        break;
        case 71: behavior = MADV_WIPEONFORK;    break;
        case 72: behavior = MADV_KEEPONFORK;    break;
        case 73: behavior = MADV_COLLAPSE;      break;
        }

        return sys_madvise(start, len_in, behavior);
}