arch/mips/kernel/syscall.c - maze/linux - Git at Google

 /*
  * 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, 1996, 1997, 2000, 2001, 05 by Ralf Baechle
  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
  * Copyright (C) 2001 MIPS Technologies, Inc.
  */
 #include <linux/capability.h>
 #include <linux/errno.h>
 #include <linux/linkage.h>
 #include <linux/mm.h>
 #include <linux/fs.h>
 #include <linux/smp.h>
 #include <linux/mman.h>
 #include <linux/ptrace.h>
 #include <linux/sched.h>
 #include <linux/string.h>
 #include <linux/syscalls.h>
 #include <linux/file.h>
 #include <linux/slab.h>
 #include <linux/utsname.h>
 #include <linux/unistd.h>
 #include <linux/sem.h>
 #include <linux/msg.h>
 #include <linux/shm.h>
 #include <linux/compiler.h>
 #include <linux/module.h>
 #include <linux/ipc.h>

 #include <asm/branch.h>
 #include <asm/cachectl.h>
 #include <asm/cacheflush.h>
 #include <asm/asm-offsets.h>
 #include <asm/signal.h>
 #include <asm/sim.h>
 #include <asm/shmparam.h>
 #include <asm/sysmips.h>
 #include <asm/uaccess.h>

 /*
  * For historic reasons the pipe(2) syscall on MIPS has an unusual calling
  * convention.  It returns results in registers $v0 / $v1 which means there
  * is no need for it to do verify the validity of a userspace pointer
  * argument.  Historically that used to be expensive in Linux.  These days
  * the performance advantage is negligible.
  */
 asmlinkage int sysm_pipe(nabi_no_regargs volatile struct pt_regs regs)
 {
 	int fd[2];
 	int error, res;

 	error = do_pipe_flags(fd, 0);
 	if (error) {
 		res = error;
 		goto out;
 	}
 	regs.regs[3] = fd[1];
 	res = fd[0];
 out:
 	return res;
 }

 unsigned long shm_align_mask = PAGE_SIZE - 1;	/* Sane caches */

 EXPORT_SYMBOL(shm_align_mask);

 #define COLOUR_ALIGN(addr,pgoff)				\
 	((((addr) + shm_align_mask) & ~shm_align_mask) +	\
 	 (((pgoff) << PAGE_SHIFT) & shm_align_mask))

 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
 	unsigned long len, unsigned long pgoff, unsigned long flags)
 {
 	struct vm_area_struct * vmm;
 	int do_color_align;
 	unsigned long task_size;

 	task_size = STACK_TOP;

 	if (len > task_size)
 		return -ENOMEM;

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

 		/*
 		 * We do not accept a shared mapping if it would violate
 		 * cache aliasing constraints.
 		 */
 		if ((flags & MAP_SHARED) && (addr & shm_align_mask))
 			return -EINVAL;
 		return addr;
 	}

 	do_color_align = 0;
 	if (filp || (flags & MAP_SHARED))
 		do_color_align = 1;
 	if (addr) {
 		if (do_color_align)
 			addr = COLOUR_ALIGN(addr, pgoff);
 		else
 			addr = PAGE_ALIGN(addr);
 		vmm = find_vma(current->mm, addr);
 		if (task_size - len >= addr &&
 		    (!vmm || addr + len <= vmm->vm_start))
 			return addr;
 	}
 	addr = TASK_UNMAPPED_BASE;
 	if (do_color_align)
 		addr = COLOUR_ALIGN(addr, pgoff);
 	else
 		addr = PAGE_ALIGN(addr);

 	for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
 		/* At this point:  (!vmm || addr < vmm->vm_end). */
 		if (task_size - len < addr)
 			return -ENOMEM;
 		if (!vmm || addr + len <= vmm->vm_start)
 			return addr;
 		addr = vmm->vm_end;
 		if (do_color_align)
 			addr = COLOUR_ALIGN(addr, pgoff);
 	}
 }

 /* common code for old and new mmaps */
 static inline unsigned long
 do_mmap2(unsigned long addr, unsigned long len, unsigned long prot,
         unsigned long flags, unsigned long fd, unsigned long pgoff)
 {
 	unsigned long error = -EBADF;
 	struct file * file = NULL;

 	flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
 	if (!(flags & MAP_ANONYMOUS)) {
 		file = fget(fd);
 		if (!file)
 			goto out;
 	}

 	down_write(&current->mm->mmap_sem);
 	error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
 	up_write(&current->mm->mmap_sem);

 	if (file)
 		fput(file);
 out:
 	return error;
 }

 SYSCALL_DEFINE6(mips_mmap, unsigned long, addr, unsigned long, len,
 	unsigned long, prot, unsigned long, flags, unsigned long,
 	fd, off_t, offset)
 {
 	unsigned long result;

 	result = -EINVAL;
 	if (offset & ~PAGE_MASK)
 		goto out;

 	result = do_mmap2(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);

 out:
 	return result;
 }

 SYSCALL_DEFINE6(mips_mmap2, unsigned long, addr, unsigned long, len,
 	unsigned long, prot, unsigned long, flags, unsigned long, fd,
 	unsigned long, pgoff)
 {
 	if (pgoff & (~PAGE_MASK >> 12))
 		return -EINVAL;

 	return do_mmap2(addr, len, prot, flags, fd, pgoff >> (PAGE_SHIFT-12));
 }

 save_static_function(sys_fork);
 static int __used noinline
 _sys_fork(nabi_no_regargs struct pt_regs regs)
 {
 	return do_fork(SIGCHLD, regs.regs[29], &regs, 0, NULL, NULL);
 }

 save_static_function(sys_clone);
 static int __used noinline
 _sys_clone(nabi_no_regargs struct pt_regs regs)
 {
 	unsigned long clone_flags;
 	unsigned long newsp;
 	int __user *parent_tidptr, *child_tidptr;

 	clone_flags = regs.regs[4];
 	newsp = regs.regs[5];
 	if (!newsp)
 		newsp = regs.regs[29];
 	parent_tidptr = (int __user *) regs.regs[6];
 #ifdef CONFIG_32BIT
 	/* We need to fetch the fifth argument off the stack.  */
 	child_tidptr = NULL;
 	if (clone_flags & (CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID)) {
 		int __user *__user *usp = (int __user *__user *) regs.regs[29];
 		if (regs.regs[2] == __NR_syscall) {
 			if (get_user (child_tidptr, &usp[5]))
 				return -EFAULT;
 		}
 		else if (get_user (child_tidptr, &usp[4]))
 			return -EFAULT;
 	}
 #else
 	child_tidptr = (int __user *) regs.regs[8];
 #endif
 	return do_fork(clone_flags, newsp, &regs, 0,
 	               parent_tidptr, child_tidptr);
 }

 /*
  * sys_execve() executes a new program.
  */
 asmlinkage int sys_execve(nabi_no_regargs struct pt_regs regs)
 {
 	int error;
 	char * filename;

 	filename = getname((char __user *) (long)regs.regs[4]);
 	error = PTR_ERR(filename);
 	if (IS_ERR(filename))
 		goto out;
 	error = do_execve(filename, (char __user *__user *) (long)regs.regs[5],
 	                  (char __user *__user *) (long)regs.regs[6], &regs);
 	putname(filename);

 out:
 	return error;
 }

 /*
  * Compacrapability ...
  */
 SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
 {
 	if (name && !copy_to_user(name, utsname(), sizeof (*name)))
 		return 0;
 	return -EFAULT;
 }

 /*
  * Compacrapability ...
  */
 SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
 {
 	int error;

 	if (!name)
 		return -EFAULT;
 	if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname)))
 		return -EFAULT;

 	error = __copy_to_user(&name->sysname, &utsname()->sysname,
 			       __OLD_UTS_LEN);
 	error -= __put_user(0, name->sysname + __OLD_UTS_LEN);
 	error -= __copy_to_user(&name->nodename, &utsname()->nodename,
 				__OLD_UTS_LEN);
 	error -= __put_user(0, name->nodename + __OLD_UTS_LEN);
 	error -= __copy_to_user(&name->release, &utsname()->release,
 				__OLD_UTS_LEN);
 	error -= __put_user(0, name->release + __OLD_UTS_LEN);
 	error -= __copy_to_user(&name->version, &utsname()->version,
 				__OLD_UTS_LEN);
 	error -= __put_user(0, name->version + __OLD_UTS_LEN);
 	error -= __copy_to_user(&name->machine, &utsname()->machine,
 				__OLD_UTS_LEN);
 	error = __put_user(0, name->machine + __OLD_UTS_LEN);
 	error = error ? -EFAULT : 0;

 	return error;
 }

 SYSCALL_DEFINE1(set_thread_area, unsigned long, addr)
 {
 	struct thread_info *ti = task_thread_info(current);

 	ti->tp_value = addr;
 	if (cpu_has_userlocal)
 		write_c0_userlocal(addr);

 	return 0;
 }

 asmlinkage int _sys_sysmips(long cmd, long arg1, long arg2, long arg3)
 {
 	switch (cmd) {
 	case MIPS_ATOMIC_SET:
 		printk(KERN_CRIT "How did I get here?\n");
 		return -EINVAL;

 	case MIPS_FIXADE:
 		if (arg1 & ~3)
 			return -EINVAL;

 		if (arg1 & 1)
 			set_thread_flag(TIF_FIXADE);
 		else
 			clear_thread_flag(TIF_FIXADE);
 		if (arg1 & 2)
 			set_thread_flag(TIF_LOGADE);
 		else
 			clear_thread_flag(TIF_FIXADE);

 		return 0;

 	case FLUSH_CACHE:
 		__flush_cache_all();
 		return 0;
 	}

 	return -EINVAL;
 }

 /*
  * sys_ipc() is the de-multiplexer for the SysV IPC calls..
  *
  * This is really horribly ugly.
  */
 SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, int, second,
 	unsigned long, third, void __user *, ptr, long, fifth)
 {
 	int version, ret;

 	version = call >> 16; /* hack for backward compatibility */
 	call &= 0xffff;

 	switch (call) {
 	case SEMOP:
 		return sys_semtimedop(first, (struct sembuf __user *)ptr,
 		                      second, NULL);
 	case SEMTIMEDOP:
 		return sys_semtimedop(first, (struct sembuf __user *)ptr,
 				      second,
 				      (const struct timespec __user *)fifth);
 	case SEMGET:
 		return sys_semget(first, second, third);
 	case SEMCTL: {
 		union semun fourth;
 		if (!ptr)
 			return -EINVAL;
 		if (get_user(fourth.__pad, (void __user *__user *) ptr))
 			return -EFAULT;
 		return sys_semctl(first, second, third, fourth);
 	}

 	case MSGSND:
 		return sys_msgsnd(first, (struct msgbuf __user *) ptr,
 				  second, third);
 	case MSGRCV:
 		switch (version) {
 		case 0: {
 			struct ipc_kludge tmp;
 			if (!ptr)
 				return -EINVAL;

 			if (copy_from_user(&tmp,
 					   (struct ipc_kludge __user *) ptr,
 					   sizeof(tmp)))
 				return -EFAULT;
 			return sys_msgrcv(first, tmp.msgp, second,
 					  tmp.msgtyp, third);
 		}
 		default:
 			return sys_msgrcv(first,
 					  (struct msgbuf __user *) ptr,
 					  second, fifth, third);
 		}
 	case MSGGET:
 		return sys_msgget((key_t) first, second);
 	case MSGCTL:
 		return sys_msgctl(first, second,
 				  (struct msqid_ds __user *) ptr);

 	case SHMAT:
 		switch (version) {
 		default: {
 			unsigned long raddr;
 			ret = do_shmat(first, (char __user *) ptr, second,
 				       &raddr);
 			if (ret)
 				return ret;
 			return put_user(raddr, (unsigned long __user *) third);
 		}
 		case 1:	/* iBCS2 emulator entry point */
 			if (!segment_eq(get_fs(), get_ds()))
 				return -EINVAL;
 			return do_shmat(first, (char __user *) ptr, second,
 				        (unsigned long *) third);
 		}
 	case SHMDT:
 		return sys_shmdt((char __user *)ptr);
 	case SHMGET:
 		return sys_shmget(first, second, third);
 	case SHMCTL:
 		return sys_shmctl(first, second,
 				  (struct shmid_ds __user *) ptr);
 	default:
 		return -ENOSYS;
 	}
 }

 /*
  * No implemented yet ...
  */
 SYSCALL_DEFINE3(cachectl, char *, addr, int, nbytes, int, op)
 {
 	return -ENOSYS;
 }

 /*
  * If we ever come here the user sp is bad.  Zap the process right away.
  * Due to the bad stack signaling wouldn't work.
  */
 asmlinkage void bad_stack(void)
 {
 	do_exit(SIGSEGV);
 }

 /*
  * Do a system call from kernel instead of calling sys_execve so we
  * end up with proper pt_regs.
  */
 int kernel_execve(const char *filename, char *const argv[], char *const envp[])
 {
 	register unsigned long __a0 asm("$4") = (unsigned long) filename;
 	register unsigned long __a1 asm("$5") = (unsigned long) argv;
 	register unsigned long __a2 asm("$6") = (unsigned long) envp;
 	register unsigned long __a3 asm("$7");
 	unsigned long __v0;

 	__asm__ volatile ("					\n"
 	"	.set	noreorder				\n"
 	"	li	$2, %5		# __NR_execve		\n"
 	"	syscall						\n"
 	"	move	%0, $2					\n"
 	"	.set	reorder					\n"
 	: "=&r" (__v0), "=r" (__a3)
 	: "r" (__a0), "r" (__a1), "r" (__a2), "i" (__NR_execve)
 	: "$2", "$8", "$9", "$10", "$11", "$12", "$13", "$14", "$15", "$24",
 	  "memory");

 	if (__a3 == 0)
 		return __v0;

 	return -__v0;
 }
	/*
	* 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, 1996, 1997, 2000, 2001, 05 by Ralf Baechle
	* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
	* Copyright (C) 2001 MIPS Technologies, Inc.
	*/
	#include <linux/capability.h>
	#include <linux/errno.h>
	#include <linux/linkage.h>
	#include <linux/mm.h>
	#include <linux/fs.h>
	#include <linux/smp.h>
	#include <linux/mman.h>
	#include <linux/ptrace.h>
	#include <linux/sched.h>
	#include <linux/string.h>
	#include <linux/syscalls.h>
	#include <linux/file.h>
	#include <linux/slab.h>
	#include <linux/utsname.h>
	#include <linux/unistd.h>
	#include <linux/sem.h>
	#include <linux/msg.h>
	#include <linux/shm.h>
	#include <linux/compiler.h>
	#include <linux/module.h>
	#include <linux/ipc.h>

	#include <asm/branch.h>
	#include <asm/cachectl.h>
	#include <asm/cacheflush.h>
	#include <asm/asm-offsets.h>
	#include <asm/signal.h>
	#include <asm/sim.h>
	#include <asm/shmparam.h>
	#include <asm/sysmips.h>
	#include <asm/uaccess.h>

	/*
	* For historic reasons the pipe(2) syscall on MIPS has an unusual calling
	* convention. It returns results in registers $v0 / $v1 which means there
	* is no need for it to do verify the validity of a userspace pointer
	* argument. Historically that used to be expensive in Linux. These days
	* the performance advantage is negligible.
	*/
	asmlinkage int sysm_pipe(nabi_no_regargs volatile struct pt_regs regs)
	{
	int fd[2];
	int error, res;

	error = do_pipe_flags(fd, 0);
	if (error) {
	res = error;
	goto out;
	}
	regs.regs[3] = fd[1];
	res = fd[0];
	out:
	return res;
	}

	unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */

	EXPORT_SYMBOL(shm_align_mask);

	#define COLOUR_ALIGN(addr,pgoff) \
	((((addr) + shm_align_mask) & ~shm_align_mask) + \
	(((pgoff) << PAGE_SHIFT) & shm_align_mask))

	unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
	unsigned long len, unsigned long pgoff, unsigned long flags)
	{
	struct vm_area_struct * vmm;
	int do_color_align;
	unsigned long task_size;

	task_size = STACK_TOP;

	if (len > task_size)
	return -ENOMEM;

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

	/*
	* We do not accept a shared mapping if it would violate
	* cache aliasing constraints.
	*/
	if ((flags & MAP_SHARED) && (addr & shm_align_mask))
	return -EINVAL;
	return addr;
	}

	do_color_align = 0;
	if (filp \|\| (flags & MAP_SHARED))
	do_color_align = 1;
	if (addr) {
	if (do_color_align)
	addr = COLOUR_ALIGN(addr, pgoff);
	else
	addr = PAGE_ALIGN(addr);
	vmm = find_vma(current->mm, addr);
	if (task_size - len >= addr &&
	(!vmm \|\| addr + len <= vmm->vm_start))
	return addr;
	}
	addr = TASK_UNMAPPED_BASE;
	if (do_color_align)
	addr = COLOUR_ALIGN(addr, pgoff);
	else
	addr = PAGE_ALIGN(addr);

	for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
	/* At this point: (!vmm \|\| addr < vmm->vm_end). */
	if (task_size - len < addr)
	return -ENOMEM;
	if (!vmm \|\| addr + len <= vmm->vm_start)
	return addr;
	addr = vmm->vm_end;
	if (do_color_align)
	addr = COLOUR_ALIGN(addr, pgoff);
	}
	}

	/* common code for old and new mmaps */
	static inline unsigned long
	do_mmap2(unsigned long addr, unsigned long len, unsigned long prot,
	unsigned long flags, unsigned long fd, unsigned long pgoff)
	{
	unsigned long error = -EBADF;
	struct file * file = NULL;

	flags &= ~(MAP_EXECUTABLE \| MAP_DENYWRITE);
	if (!(flags & MAP_ANONYMOUS)) {
	file = fget(fd);
	if (!file)
	goto out;
	}

	down_write(&current->mm->mmap_sem);
	error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
	up_write(&current->mm->mmap_sem);

	if (file)
	fput(file);
	out:
	return error;
	}

	SYSCALL_DEFINE6(mips_mmap, unsigned long, addr, unsigned long, len,
	unsigned long, prot, unsigned long, flags, unsigned long,
	fd, off_t, offset)
	{
	unsigned long result;

	result = -EINVAL;
	if (offset & ~PAGE_MASK)
	goto out;

	result = do_mmap2(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);

	out:
	return result;
	}

	SYSCALL_DEFINE6(mips_mmap2, unsigned long, addr, unsigned long, len,
	unsigned long, prot, unsigned long, flags, unsigned long, fd,
	unsigned long, pgoff)
	{
	if (pgoff & (~PAGE_MASK >> 12))
	return -EINVAL;

	return do_mmap2(addr, len, prot, flags, fd, pgoff >> (PAGE_SHIFT-12));
	}

	save_static_function(sys_fork);
	static int __used noinline
	_sys_fork(nabi_no_regargs struct pt_regs regs)
	{
	return do_fork(SIGCHLD, regs.regs[29], &regs, 0, NULL, NULL);
	}

	save_static_function(sys_clone);
	static int __used noinline
	_sys_clone(nabi_no_regargs struct pt_regs regs)
	{
	unsigned long clone_flags;
	unsigned long newsp;
	int __user parent_tidptr, child_tidptr;

	clone_flags = regs.regs[4];
	newsp = regs.regs[5];
	if (!newsp)
	newsp = regs.regs[29];
	parent_tidptr = (int __user *) regs.regs[6];
	#ifdef CONFIG_32BIT
	/* We need to fetch the fifth argument off the stack. */
	child_tidptr = NULL;
	if (clone_flags & (CLONE_CHILD_SETTID \| CLONE_CHILD_CLEARTID)) {
	int __user __user usp = (int __user __user ) regs.regs[29];
	if (regs.regs[2] == __NR_syscall) {
	if (get_user (child_tidptr, &usp[5]))
	return -EFAULT;
	}
	else if (get_user (child_tidptr, &usp[4]))
	return -EFAULT;
	}
	#else
	child_tidptr = (int __user *) regs.regs[8];
	#endif
	return do_fork(clone_flags, newsp, &regs, 0,
	parent_tidptr, child_tidptr);
	}

	/*
	* sys_execve() executes a new program.
	*/
	asmlinkage int sys_execve(nabi_no_regargs struct pt_regs regs)
	{
	int error;
	char * filename;

	filename = getname((char __user *) (long)regs.regs[4]);
	error = PTR_ERR(filename);
	if (IS_ERR(filename))
	goto out;
	error = do_execve(filename, (char __user __user ) (long)regs.regs[5],
	(char __user __user ) (long)regs.regs[6], &regs);
	putname(filename);

	out:
	return error;
	}

	/*
	* Compacrapability ...
	*/
	SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
	{
	if (name && !copy_to_user(name, utsname(), sizeof (*name)))
	return 0;
	return -EFAULT;
	}

	/*
	* Compacrapability ...
	*/
	SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
	{
	int error;

	if (!name)
	return -EFAULT;
	if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname)))
	return -EFAULT;

	error = __copy_to_user(&name->sysname, &utsname()->sysname,
	__OLD_UTS_LEN);
	error -= __put_user(0, name->sysname + __OLD_UTS_LEN);
	error -= __copy_to_user(&name->nodename, &utsname()->nodename,
	__OLD_UTS_LEN);
	error -= __put_user(0, name->nodename + __OLD_UTS_LEN);
	error -= __copy_to_user(&name->release, &utsname()->release,
	__OLD_UTS_LEN);
	error -= __put_user(0, name->release + __OLD_UTS_LEN);
	error -= __copy_to_user(&name->version, &utsname()->version,
	__OLD_UTS_LEN);
	error -= __put_user(0, name->version + __OLD_UTS_LEN);
	error -= __copy_to_user(&name->machine, &utsname()->machine,
	__OLD_UTS_LEN);
	error = __put_user(0, name->machine + __OLD_UTS_LEN);
	error = error ? -EFAULT : 0;

	return error;
	}

	SYSCALL_DEFINE1(set_thread_area, unsigned long, addr)
	{
	struct thread_info *ti = task_thread_info(current);

	ti->tp_value = addr;
	if (cpu_has_userlocal)
	write_c0_userlocal(addr);

	return 0;
	}

	asmlinkage int _sys_sysmips(long cmd, long arg1, long arg2, long arg3)
	{
	switch (cmd) {
	case MIPS_ATOMIC_SET:
	printk(KERN_CRIT "How did I get here?\n");
	return -EINVAL;

	case MIPS_FIXADE:
	if (arg1 & ~3)
	return -EINVAL;

	if (arg1 & 1)
	set_thread_flag(TIF_FIXADE);
	else
	clear_thread_flag(TIF_FIXADE);
	if (arg1 & 2)
	set_thread_flag(TIF_LOGADE);
	else
	clear_thread_flag(TIF_FIXADE);

	return 0;

	case FLUSH_CACHE:
	__flush_cache_all();
	return 0;
	}

	return -EINVAL;
	}

	/*
	* sys_ipc() is the de-multiplexer for the SysV IPC calls..
	*
	* This is really horribly ugly.
	*/
	SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, int, second,
	unsigned long, third, void __user *, ptr, long, fifth)
	{
	int version, ret;

	version = call >> 16; /* hack for backward compatibility */
	call &= 0xffff;

	switch (call) {
	case SEMOP:
	return sys_semtimedop(first, (struct sembuf __user *)ptr,
	second, NULL);
	case SEMTIMEDOP:
	return sys_semtimedop(first, (struct sembuf __user *)ptr,
	second,
	(const struct timespec __user *)fifth);
	case SEMGET:
	return sys_semget(first, second, third);
	case SEMCTL: {
	union semun fourth;
	if (!ptr)
	return -EINVAL;
	if (get_user(fourth.__pad, (void __user __user ) ptr))
	return -EFAULT;
	return sys_semctl(first, second, third, fourth);
	}

	case MSGSND:
	return sys_msgsnd(first, (struct msgbuf __user *) ptr,
	second, third);
	case MSGRCV:
	switch (version) {
	case 0: {
	struct ipc_kludge tmp;
	if (!ptr)
	return -EINVAL;

	if (copy_from_user(&tmp,
	(struct ipc_kludge __user *) ptr,
	sizeof(tmp)))
	return -EFAULT;
	return sys_msgrcv(first, tmp.msgp, second,
	tmp.msgtyp, third);
	}
	default:
	return sys_msgrcv(first,
	(struct msgbuf __user *) ptr,
	second, fifth, third);
	}
	case MSGGET:
	return sys_msgget((key_t) first, second);
	case MSGCTL:
	return sys_msgctl(first, second,
	(struct msqid_ds __user *) ptr);

	case SHMAT:
	switch (version) {
	default: {
	unsigned long raddr;
	ret = do_shmat(first, (char __user *) ptr, second,
	&raddr);
	if (ret)
	return ret;
	return put_user(raddr, (unsigned long __user *) third);
	}
	case 1: /* iBCS2 emulator entry point */
	if (!segment_eq(get_fs(), get_ds()))
	return -EINVAL;
	return do_shmat(first, (char __user *) ptr, second,
	(unsigned long *) third);
	}
	case SHMDT:
	return sys_shmdt((char __user *)ptr);
	case SHMGET:
	return sys_shmget(first, second, third);
	case SHMCTL:
	return sys_shmctl(first, second,
	(struct shmid_ds __user *) ptr);
	default:
	return -ENOSYS;
	}
	}

	/*
	* No implemented yet ...
	*/
	SYSCALL_DEFINE3(cachectl, char *, addr, int, nbytes, int, op)
	{
	return -ENOSYS;
	}

	/*
	* If we ever come here the user sp is bad. Zap the process right away.
	* Due to the bad stack signaling wouldn't work.
	*/
	asmlinkage void bad_stack(void)
	{
	do_exit(SIGSEGV);
	}

	/*
	* Do a system call from kernel instead of calling sys_execve so we
	* end up with proper pt_regs.
	*/
	int kernel_execve(const char filename, char const argv[], char *const envp[])
	{
	register unsigned long __a0 asm("$4") = (unsigned long) filename;
	register unsigned long __a1 asm("$5") = (unsigned long) argv;
	register unsigned long __a2 asm("$6") = (unsigned long) envp;
	register unsigned long __a3 asm("$7");
	unsigned long __v0;

	__asm__ volatile (" \n"
	" .set noreorder \n"
	" li $2, %5 # __NR_execve \n"
	" syscall \n"
	" move %0, $2 \n"
	" .set reorder \n"
	: "=&r" (__v0), "=r" (__a3)
	: "r" (__a0), "r" (__a1), "r" (__a2), "i" (__NR_execve)
	: "$2", "$8", "$9", "$10", "$11", "$12", "$13", "$14", "$15", "$24",
	"memory");

	if (__a3 == 0)
	return __v0;

	return -__v0;
	}