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/*

 * MIPS specific syscall handling functions and syscalls

 *

 * This file is subject to the terms and conditions of the GNU General Public

 * License.  See the file "COPYING" in the main directory of this archive

 * for more details.

 *

 * Copyright (C) 1995 by Ralf Baechle

 */

#include <linux/linkage.h>

#include <linux/mm.h>

#include <linux/mman.h>

#include <linux/sched.h>

#include <linux/unistd.h>

#include <asm/ptrace.h>

#include <asm/segment.h>

#include <asm/signal.h>

extern asmlinkage void syscall_trace(void);

typedef asmlinkage int (*syscall_t)(void *a0,...);

extern asmlinkage int do_syscalls(struct pt_regs *regs, syscall_t fun,

                                  int narg);

extern syscall_t sys_call_table[];

extern unsigned char sys_narg_table[];

asmlinkage int sys_pipe(struct pt_regs *regs)

{

        int fd[2];

        int error;

        error = do_pipe(fd);

        if (error)

                return error;

        regs->reg2 = fd[0];

        regs->reg3 = fd[1];

        return 0;

}

asmlinkage unsigned long sys_mmap(unsigned long addr, size_t len, int prot,

                                  int flags, int fd, off_t offset)

{

        struct file * file = NULL;

        if (flags & MAP_RENAME) {

                if (fd >= NR_OPEN || !(file = current->files->fd[fd]))

                        return -EBADF;

        }

        flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);

        return do_mmap(file, addr, len, prot, flags, offset);

}

asmlinkage int sys_idle(void)

{

        if (current->pid != 0)

                return -EPERM;

        /* endless idle loop with no priority at all */

        current->counter = -100;

        for (;;) {

                /*

                 * R4[26]00 have wait, R4[04]00 don't.

                 */

                if (wait_available && !need_resched)

                        __asm__(".set\tmips3\n\t"

                                "wait\n\t"

                                ".set\tmips0\n\t");

                schedule();

        }

}

asmlinkage int sys_fork(struct pt_regs *regs)

{

        return do_fork(SIGCHLD, regs->reg29, regs);

}

asmlinkage int sys_clone(struct pt_regs *regs)

{

        unsigned long clone_flags;

        unsigned long newsp;

        clone_flags = regs->reg4;

        newsp = regs->reg5;

        if (!newsp)

                newsp = regs->reg29;

        return do_fork(clone_flags, newsp, regs);

}

/*

 * sys_execve() executes a new program.

 */

asmlinkage int sys_execve(struct pt_regs *regs)

{

        int error;

        char * filename;

        error = getname((char *) regs->reg4, &filename);

        if (error)

                return error;

        error = do_execve(filename, (char **) regs->reg5,

                          (char **) regs->reg6, regs);

        putname(filename);

        return error;

}

/*

 * Do the indirect syscall syscall.

 */

asmlinkage int sys_syscall(unsigned long a0, unsigned long a1, unsigned long a2,

                           unsigned long a3, unsigned long a4, unsigned long a5,

                           unsigned long a6)

{

        syscall_t syscall;

        if (a0 > __NR_Linux + __NR_Linux_syscalls)

                return -ENOSYS;

        syscall = sys_call_table[a0];

        /*

         * Prevent stack overflow by recursive

         * syscall(__NR_syscall, __NR_syscall,...);

         */

        if (syscall == (syscall_t) sys_syscall)

                return -EINVAL;

        if (syscall == NULL)

                return -ENOSYS;

        return syscall((void *)a0, a1, a2, a3, a4, a5, a6);

}

void do_sys(struct pt_regs *regs)

{

        unsigned long syscallnr, usp;

        syscall_t syscall;

        int errno, narg;

        /*

         * Compute the return address;

         */

        if (regs->cp0_cause & CAUSEF_BD)

        {

                /*

                 * This syscall is in a branch delay slot.  Since we don't do

                 * branch delay slot handling we would get a process trying

                 * to do syscalls ever and ever again.  So better zap it.

                 */

                printk("%s: syscall in branch delay slot.\n", current->comm);

                current->sig->action[SIGILL-1].sa_handler = NULL;

                current->blocked &= ~(1<<(SIGILL-1));

                send_sig(SIGILL, current, 1);

                return;

        }

        regs->cp0_epc += 4;

        syscallnr = regs->reg2;

        if (syscallnr > (__NR_Linux + __NR_Linux_syscalls))

                goto illegal_syscall;

        syscall = sys_call_table[syscallnr];

        if (syscall == NULL)

                goto illegal_syscall;

        narg = sys_narg_table[syscallnr];

        if (narg > 4)

        {

                /*

                 * Verify that we can safely get the additional parameters

                 * from the user stack.  Of course I could read the params

                 * from unaligned addresses ...  Consider this a programming

                 * course caliber .45.

                 */

                usp = regs->reg29;

                if (usp & 3)

                {

                        printk("unaligned usp\n");

                        send_sig(SIGSEGV, current, 1);

                        regs->reg2 = EFAULT;

                        regs->reg7 = 1;

                        return;

                }

                errno = verify_area(VERIFY_READ, (void *) (usp + 16),

                                    (narg - 4) * sizeof(unsigned long));

                if (errno < 0)

                        goto bad_syscall;

        }

        if ((current->flags & PF_TRACESYS) == 0)

        {

                errno = do_syscalls(regs, syscall, narg);

                if (errno < 0 || current->errno)

                        goto bad_syscall;

                regs->reg2 = errno;

                regs->reg7 = 0;

        }

        else

        {

                syscall_trace();

                errno = do_syscalls(regs, syscall, narg);

                if (errno < 0 || current->errno)

                {

                        regs->reg2 = -errno;

                        regs->reg7 = 1;

                }

                else

                {

                        regs->reg2 = errno;

                        regs->reg7 = 0;

                }

                syscall_trace();

        }

        return;

bad_syscall:

        regs->reg2 = -errno;

        regs->reg7 = 1;

        return;

illegal_syscall:

        regs->reg2 = ENOSYS;

        regs->reg7 = 1;

        return;

}