// SPDX-License-Identifier: GPL-2.0
/* linux/arch/sparc64/kernel/sys_sparc.c
 *
 * This file contains various random system calls that
 * have a non-standard calling sequence on the Linux/sparc
 * platform.
 */

#include <linux/errno.h>
#include <linux/types.h>
#include <linux/sched/signal.h>
#include <linux/sched/mm.h>
#include <linux/sched/debug.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/mm.h>
#include <linux/sem.h>
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/stat.h>
#include <linux/mman.h>
#include <linux/utsname.h>
#include <linux/smp.h>
#include <linux/slab.h>
#include <linux/syscalls.h>
#include <linux/ipc.h>
#include <linux/personality.h>
#include <linux/random.h>
#include <linux/export.h>
#include <linux/context_tracking.h>
#include <linux/timex.h>
#include <linux/uaccess.h>
#include <linux/hugetlb.h>

#include <asm/utrap.h>
#include <asm/unistd.h>

#include "entry.h"
#include "kernel.h"
#include "systbls.h"

/* #define DEBUG_UNIMP_SYSCALL */

SYSCALL_DEFINE0(getpagesize)
{
        return PAGE_SIZE;
}

/* Does addr --> addr+len fall within 4GB of the VA-space hole or
 * overflow past the end of the 64-bit address space?
 */
static inline int invalid_64bit_range(unsigned long addr, unsigned long len)
{
        unsigned long va_exclude_start, va_exclude_end;

        va_exclude_start = VA_EXCLUDE_START;
        va_exclude_end   = VA_EXCLUDE_END;

        if (unlikely(len >= va_exclude_start))
                return 1;

        if (unlikely((addr + len) < addr))
                return 1;

        if (unlikely((addr >= va_exclude_start && addr < va_exclude_end) ||
                     ((addr + len) >= va_exclude_start &&
                      (addr + len) < va_exclude_end)))
                return 1;

        return 0;
}

/* These functions differ from the default implementations in
 * mm/mmap.c in two ways:
 *
 * 1) For file backed MAP_SHARED mmap()'s we D-cache color align,
 *    for fixed such mappings we just validate what the user gave us.
 * 2) For 64-bit tasks we avoid mapping anything within 4GB of
 *    the spitfire/niagara VA-hole.
 */

static inline unsigned long COLOR_ALIGN(unsigned long addr,
                                         unsigned long pgoff)
{
        unsigned long base = (addr+SHMLBA-1)&~(SHMLBA-1);
        unsigned long off = (pgoff<<PAGE_SHIFT) & (SHMLBA-1);

        return base + off;
}

static unsigned long get_align_mask(struct file *filp, unsigned long flags)
{
        if (filp && is_file_hugepages(filp))
                return huge_page_mask_align(filp);
        if (filp || (flags & MAP_SHARED))
                return PAGE_MASK & (SHMLBA - 1);

        return 0;
}

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)
{
        struct mm_struct *mm = current->mm;
        struct vm_area_struct * vma;
        unsigned long task_size = TASK_SIZE;
        int do_color_align;
        struct vm_unmapped_area_info info = {};
        bool file_hugepage = false;

        if (filp && is_file_hugepages(filp))
                file_hugepage = true;

        if (flags & MAP_FIXED) {
                /* We do not accept a shared mapping if it would violate
                 * cache aliasing constraints.
                 */
                if (!file_hugepage && (flags & MAP_SHARED) &&
                    ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
                        return -EINVAL;
                return addr;
        }

        if (test_thread_flag(TIF_32BIT))
                task_size = STACK_TOP32;
        if (unlikely(len > task_size || len >= VA_EXCLUDE_START))
                return -ENOMEM;

        do_color_align = 0;
        if ((filp || (flags & MAP_SHARED)) && !file_hugepage)
                do_color_align = 1;

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

                vma = find_vma(mm, addr);
                if (task_size - len >= addr &&
                    (!vma || addr + len <= vm_start_gap(vma)))
                        return addr;
        }

        info.length = len;
        info.low_limit = TASK_UNMAPPED_BASE;
        info.high_limit = min(task_size, VA_EXCLUDE_START);
        info.align_mask = get_align_mask(filp, flags);
        if (!file_hugepage)
                info.align_offset = pgoff << PAGE_SHIFT;
        addr = vm_unmapped_area(&info);

        if ((addr & ~PAGE_MASK) && task_size > VA_EXCLUDE_END) {
                VM_BUG_ON(addr != -ENOMEM);
                info.low_limit = VA_EXCLUDE_END;
                info.high_limit = task_size;
                addr = vm_unmapped_area(&info);
        }

        return addr;
}

unsigned long
arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
                          const unsigned long len, const unsigned long pgoff,
                          const unsigned long flags, vm_flags_t vm_flags)
{
        struct vm_area_struct *vma;
        struct mm_struct *mm = current->mm;
        unsigned long task_size = STACK_TOP32;
        unsigned long addr = addr0;
        int do_color_align;
        struct vm_unmapped_area_info info = {};
        bool file_hugepage = false;

        /* This should only ever run for 32-bit processes.  */
        BUG_ON(!test_thread_flag(TIF_32BIT));

        if (filp && is_file_hugepages(filp))
                file_hugepage = true;

        if (flags & MAP_FIXED) {
                /* We do not accept a shared mapping if it would violate
                 * cache aliasing constraints.
                 */
                if (!file_hugepage && (flags & MAP_SHARED) &&
                    ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
                        return -EINVAL;
                return addr;
        }

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

        do_color_align = 0;
        if ((filp || (flags & MAP_SHARED)) && !file_hugepage)
                do_color_align = 1;

        /* requesting a specific address */
        if (addr) {
                if (do_color_align)
                        addr = COLOR_ALIGN(addr, pgoff);
                else
                        addr = PAGE_ALIGN(addr);

                vma = find_vma(mm, addr);
                if (task_size - len >= addr &&
                    (!vma || addr + len <= vm_start_gap(vma)))
                        return addr;
        }

        info.flags = VM_UNMAPPED_AREA_TOPDOWN;
        info.length = len;
        info.low_limit = PAGE_SIZE;
        info.high_limit = mm->mmap_base;
        info.align_mask = get_align_mask(filp, flags);
        if (!file_hugepage)
                info.align_offset = pgoff << PAGE_SHIFT;
        addr = vm_unmapped_area(&info);

        /*
         * 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.
         */
        if (addr & ~PAGE_MASK) {
                VM_BUG_ON(addr != -ENOMEM);
                info.flags = 0;
                info.low_limit = TASK_UNMAPPED_BASE;
                info.high_limit = STACK_TOP32;
                addr = vm_unmapped_area(&info);
        }

        return addr;
}

/* Try to align mapping such that we align it as much as possible. */
unsigned long get_fb_unmapped_area(struct file *filp, unsigned long orig_addr, unsigned long len, unsigned long pgoff, unsigned long flags)
{
        unsigned long align_goal, addr = -ENOMEM;

        if (flags & MAP_FIXED) {
                /* Ok, don't mess with it. */
                return mm_get_unmapped_area(NULL, orig_addr, len, pgoff, flags);
        }
        flags &= ~MAP_SHARED;

        align_goal = PAGE_SIZE;
        if (len >= (4UL * 1024 * 1024))
                align_goal = (4UL * 1024 * 1024);
        else if (len >= (512UL * 1024))
                align_goal = (512UL * 1024);
        else if (len >= (64UL * 1024))
                align_goal = (64UL * 1024);

        do {
                addr = mm_get_unmapped_area(NULL, orig_addr,
                                            len + (align_goal - PAGE_SIZE), pgoff, flags);
                if (!(addr & ~PAGE_MASK)) {
                        addr = (addr + (align_goal - 1UL)) & ~(align_goal - 1UL);
                        break;
                }

                if (align_goal == (4UL * 1024 * 1024))
                        align_goal = (512UL * 1024);
                else if (align_goal == (512UL * 1024))
                        align_goal = (64UL * 1024);
                else
                        align_goal = PAGE_SIZE;
        } while ((addr & ~PAGE_MASK) && align_goal > PAGE_SIZE);

        /* Mapping is smaller than 64K or larger areas could not
         * be obtained.
         */
        if (addr & ~PAGE_MASK)
                addr = mm_get_unmapped_area(NULL, orig_addr, len, pgoff, flags);

        return addr;
}
EXPORT_SYMBOL(get_fb_unmapped_area);

/* Essentially the same as PowerPC.  */
static unsigned long mmap_rnd(void)
{
        unsigned long rnd = 0UL;

        if (current->flags & PF_RANDOMIZE) {
                unsigned long val = get_random_long();
                if (test_thread_flag(TIF_32BIT))
                        rnd = (val % (1UL << (23UL-PAGE_SHIFT)));
                else
                        rnd = (val % (1UL << (30UL-PAGE_SHIFT)));
        }
        return rnd << PAGE_SHIFT;
}

void arch_pick_mmap_layout(struct mm_struct *mm, const struct rlimit *rlim_stack)
{
        unsigned long random_factor = mmap_rnd();
        unsigned long gap;

        /*
         * Fall back to the standard layout if the personality
         * bit is set, or if the expected stack growth is unlimited:
         */
        gap = rlim_stack->rlim_cur;
        if (!test_thread_flag(TIF_32BIT) ||
            (current->personality & ADDR_COMPAT_LAYOUT) ||
            gap == RLIM_INFINITY ||
            sysctl_legacy_va_layout) {
                mm->mmap_base = TASK_UNMAPPED_BASE + random_factor;
                mm_flags_clear(MMF_TOPDOWN, mm);
        } else {
                /* We know it's 32-bit */
                unsigned long task_size = STACK_TOP32;

                if (gap < 128 * 1024 * 1024)
                        gap = 128 * 1024 * 1024;
                if (gap > (task_size / 6 * 5))
                        gap = (task_size / 6 * 5);

                mm->mmap_base = PAGE_ALIGN(task_size - gap - random_factor);
                mm_flags_set(MMF_TOPDOWN, mm);
        }
}

/*
 * sys_pipe() is the normal C calling standard for creating
 * a pipe. It's not the way unix traditionally does this, though.
 */
SYSCALL_DEFINE0(sparc_pipe)
{
        int fd[2];
        int error;

        error = do_pipe_flags(fd, 0);
        if (error)
                goto out;
        current_pt_regs()->u_regs[UREG_I1] = fd[1];
        error = fd[0];
out:
        return error;
}

/*
 * sys_ipc() is the de-multiplexer for the SysV IPC calls..
 *
 * This is really horribly ugly.
 */

SYSCALL_DEFINE6(sparc_ipc, unsigned int, call, int, first, unsigned long, second,
                unsigned long, third, void __user *, ptr, long, fifth)
{
        long err;

        if (!IS_ENABLED(CONFIG_SYSVIPC))
                return -ENOSYS;

        /* No need for backward compatibility. We can start fresh... */
        if (call <= SEMTIMEDOP) {
                switch (call) {
                case SEMOP:
                        err = ksys_semtimedop(first, ptr,
                                              (unsigned int)second, NULL);
                        goto out;
                case SEMTIMEDOP:
                        err = ksys_semtimedop(first, ptr, (unsigned int)second,
                                (const struct __kernel_timespec __user *)
                                              (unsigned long) fifth);
                        goto out;
                case SEMGET:
                        err = ksys_semget(first, (int)second, (int)third);
                        goto out;
                case SEMCTL: {
                        err = ksys_old_semctl(first, second,
                                              (int)third | IPC_64,
                                              (unsigned long) ptr);
                        goto out;
                }
                default:
                        err = -ENOSYS;
                        goto out;
                }
        }
        if (call <= MSGCTL) {
                switch (call) {
                case MSGSND:
                        err = ksys_msgsnd(first, ptr, (size_t)second,
                                         (int)third);
                        goto out;
                case MSGRCV:
                        err = ksys_msgrcv(first, ptr, (size_t)second, fifth,
                                         (int)third);
                        goto out;
                case MSGGET:
                        err = ksys_msgget((key_t)first, (int)second);
                        goto out;
                case MSGCTL:
                        err = ksys_old_msgctl(first, (int)second | IPC_64, ptr);
                        goto out;
                default:
                        err = -ENOSYS;
                        goto out;
                }
        }
        if (call <= SHMCTL) {
                switch (call) {
                case SHMAT: {
                        ulong raddr;
                        err = do_shmat(first, ptr, (int)second, &raddr, SHMLBA);
                        if (!err) {
                                if (put_user(raddr,
                                             (ulong __user *) third))
                                        err = -EFAULT;
                        }
                        goto out;
                }
                case SHMDT:
                        err = ksys_shmdt(ptr);
                        goto out;
                case SHMGET:
                        err = ksys_shmget(first, (size_t)second, (int)third);
                        goto out;
                case SHMCTL:
                        err = ksys_old_shmctl(first, (int)second | IPC_64, ptr);
                        goto out;
                default:
                        err = -ENOSYS;
                        goto out;
                }
        } else {
                err = -ENOSYS;
        }
out:
        return err;
}

SYSCALL_DEFINE1(sparc64_personality, unsigned long, personality)
{
        long ret;

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

        return ret;
}

int sparc_mmap_check(unsigned long addr, unsigned long len)
{
        if (test_thread_flag(TIF_32BIT)) {
                if (len >= STACK_TOP32)
                        return -EINVAL;

                if (addr > STACK_TOP32 - len)
                        return -EINVAL;
        } else {
                if (len >= VA_EXCLUDE_START)
                        return -EINVAL;

                if (invalid_64bit_range(addr, len))
                        return -EINVAL;
        }

        return 0;
}

/* Linux version of mmap */
SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
                unsigned long, prot, unsigned long, flags, unsigned long, fd,
                unsigned long, off)
{
        unsigned long retval = -EINVAL;

        if ((off + PAGE_ALIGN(len)) < off)
                goto out;
        if (off & ~PAGE_MASK)
                goto out;
        retval = ksys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
out:
        return retval;
}

SYSCALL_DEFINE2(64_munmap, unsigned long, addr, size_t, len)
{
        if (invalid_64bit_range(addr, len))
                return -EINVAL;

        return vm_munmap(addr, len);
}
                
SYSCALL_DEFINE5(64_mremap, unsigned long, addr, unsigned long, old_len,
                unsigned long, new_len, unsigned long, flags,
                unsigned long, new_addr)
{
        if (test_thread_flag(TIF_32BIT))
                return -EINVAL;
        return sys_mremap(addr, old_len, new_len, flags, new_addr);
}

SYSCALL_DEFINE0(nis_syscall)
{
        static int count;
        struct pt_regs *regs = current_pt_regs();
        
        /* Don't make the system unusable, if someone goes stuck */
        if (count++ > 5)
                return -ENOSYS;

        printk ("Unimplemented SPARC system call %ld\n",regs->u_regs[1]);
#ifdef DEBUG_UNIMP_SYSCALL      
        show_regs (regs);
#endif

        return -ENOSYS;
}

/* #define DEBUG_SPARC_BREAKPOINT */

asmlinkage void sparc_breakpoint(struct pt_regs *regs)
{
        enum ctx_state prev_state = exception_enter();

        if (test_thread_flag(TIF_32BIT)) {
                regs->tpc &= 0xffffffff;
                regs->tnpc &= 0xffffffff;
        }
#ifdef DEBUG_SPARC_BREAKPOINT
        printk ("TRAP: Entering kernel PC=%lx, nPC=%lx\n", regs->tpc, regs->tnpc);
#endif
        force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->tpc);
#ifdef DEBUG_SPARC_BREAKPOINT
        printk ("TRAP: Returning to space: PC=%lx nPC=%lx\n", regs->tpc, regs->tnpc);
#endif
        exception_exit(prev_state);
}

SYSCALL_DEFINE2(getdomainname, char __user *, name, int, len)
{
        int nlen, err;
        char tmp[__NEW_UTS_LEN + 1];

        if (len < 0)
                return -EINVAL;

        down_read(&uts_sem);

        nlen = strlen(utsname()->domainname) + 1;
        err = -EINVAL;
        if (nlen > len)
                goto out_unlock;
        memcpy(tmp, utsname()->domainname, nlen);

        up_read(&uts_sem);

        if (copy_to_user(name, tmp, nlen))
                return -EFAULT;
        return 0;

out_unlock:
        up_read(&uts_sem);
        return err;
}

SYSCALL_DEFINE1(sparc_adjtimex, struct __kernel_timex __user *, txc_p)
{
        struct __kernel_timex txc;
        struct __kernel_old_timeval *tv = (void *)&txc.time;
        int ret;

        /* Copy the user data space into the kernel copy
         * structure. But bear in mind that the structures
         * may change
         */
        if (copy_from_user(&txc, txc_p, sizeof(txc)))
                return -EFAULT;

        /*
         * override for sparc64 specific timeval type: tv_usec
         * is 32 bit wide instead of 64-bit in __kernel_timex
         */
        txc.time.tv_usec = tv->tv_usec;
        ret = do_adjtimex(&txc);
        tv->tv_usec = txc.time.tv_usec;

        return copy_to_user(txc_p, &txc, sizeof(txc)) ? -EFAULT : ret;
}

SYSCALL_DEFINE2(sparc_clock_adjtime, const clockid_t, which_clock,
                struct __kernel_timex __user *, txc_p)
{
        struct __kernel_timex txc;
        struct __kernel_old_timeval *tv = (void *)&txc.time;
        int ret;

        if (!IS_ENABLED(CONFIG_POSIX_TIMERS)) {
                pr_err_once("process %d (%s) attempted a POSIX timer syscall "
                    "while CONFIG_POSIX_TIMERS is not set\n",
                    current->pid, current->comm);

                return -ENOSYS;
        }

        /* Copy the user data space into the kernel copy
         * structure. But bear in mind that the structures
         * may change
         */
        if (copy_from_user(&txc, txc_p, sizeof(txc)))
                return -EFAULT;

        /*
         * override for sparc64 specific timeval type: tv_usec
         * is 32 bit wide instead of 64-bit in __kernel_timex
         */
        txc.time.tv_usec = tv->tv_usec;
        ret = do_clock_adjtime(which_clock, &txc);
        tv->tv_usec = txc.time.tv_usec;

        return copy_to_user(txc_p, &txc, sizeof(txc)) ? -EFAULT : ret;
}

SYSCALL_DEFINE5(utrap_install, utrap_entry_t, type,
                utrap_handler_t, new_p, utrap_handler_t, new_d,
                utrap_handler_t __user *, old_p,
                utrap_handler_t __user *, old_d)
{
        if (type < UT_INSTRUCTION_EXCEPTION || type > UT_TRAP_INSTRUCTION_31)
                return -EINVAL;
        if (new_p == (utrap_handler_t)(long)UTH_NOCHANGE) {
                if (old_p) {
                        if (!current_thread_info()->utraps) {
                                if (put_user(NULL, old_p))
                                        return -EFAULT;
                        } else {
                                if (put_user((utrap_handler_t)(current_thread_info()->utraps[type]), old_p))
                                        return -EFAULT;
                        }
                }
                if (old_d) {
                        if (put_user(NULL, old_d))
                                return -EFAULT;
                }
                return 0;
        }
        if (!current_thread_info()->utraps) {
                current_thread_info()->utraps =
                        kzalloc_objs(long, UT_TRAP_INSTRUCTION_31 + 1);
                if (!current_thread_info()->utraps)
                        return -ENOMEM;
                current_thread_info()->utraps[0] = 1;
        } else {
                if ((utrap_handler_t)current_thread_info()->utraps[type] != new_p &&
                    current_thread_info()->utraps[0] > 1) {
                        unsigned long *p = current_thread_info()->utraps;

                        current_thread_info()->utraps =
                                kmalloc_objs(long, UT_TRAP_INSTRUCTION_31 + 1);
                        if (!current_thread_info()->utraps) {
                                current_thread_info()->utraps = p;
                                return -ENOMEM;
                        }
                        p[0]--;
                        current_thread_info()->utraps[0] = 1;
                        memcpy(current_thread_info()->utraps+1, p+1,
                               UT_TRAP_INSTRUCTION_31*sizeof(long));
                }
        }
        if (old_p) {
                if (put_user((utrap_handler_t)(current_thread_info()->utraps[type]), old_p))
                        return -EFAULT;
        }
        if (old_d) {
                if (put_user(NULL, old_d))
                        return -EFAULT;
        }
        current_thread_info()->utraps[type] = (long)new_p;

        return 0;
}

SYSCALL_DEFINE1(memory_ordering, unsigned long, model)
{
        struct pt_regs *regs = current_pt_regs();
        if (model >= 3)
                return -EINVAL;
        regs->tstate = (regs->tstate & ~TSTATE_MM) | (model << 14);
        return 0;
}

SYSCALL_DEFINE5(rt_sigaction, int, sig, const struct sigaction __user *, act,
                struct sigaction __user *, oact, void __user *, restorer,
                size_t, sigsetsize)
{
        struct k_sigaction new_ka, old_ka;
        int ret;

        /* XXX: Don't preclude handling different sized sigset_t's.  */
        if (sigsetsize != sizeof(sigset_t))
                return -EINVAL;

        if (act) {
                new_ka.ka_restorer = restorer;
                if (copy_from_user(&new_ka.sa, act, sizeof(*act)))
                        return -EFAULT;
        }

        ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);

        if (!ret && oact) {
                if (copy_to_user(oact, &old_ka.sa, sizeof(*oact)))
                        return -EFAULT;
        }

        return ret;
}

SYSCALL_DEFINE0(kern_features)
{
        return KERN_FEATURE_MIXED_MODE_STACK;
}