arch/sparc/kernel/sys_sparc_32.c - third_party/linux - Git at Google

 /* linux/arch/sparc/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.h>
 #include <linux/mm.h>
 #include <linux/fs.h>
 #include <linux/file.h>
 #include <linux/sem.h>
 #include <linux/msg.h>
 #include <linux/shm.h>
 #include <linux/stat.h>
 #include <linux/syscalls.h>
 #include <linux/mman.h>
 #include <linux/utsname.h>
 #include <linux/smp.h>
 #include <linux/smp_lock.h>
 #include <linux/ipc.h>

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

 /* #define DEBUG_UNIMP_SYSCALL */

 /* XXX Make this per-binary type, this way we can detect the type of
  * XXX a binary.  Every Sparc executable calls this very early on.
  */
 asmlinkage unsigned long sys_getpagesize(void)
 {
 	return PAGE_SIZE; /* Possibly older binaries want 8192 on sun4's? */
 }

 #define COLOUR_ALIGN(addr)      (((addr)+SHMLBA-1)&~(SHMLBA-1))

 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;

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

 	/* See asm-sparc/uaccess.h */
 	if (len > TASK_SIZE - PAGE_SIZE)
 		return -ENOMEM;
 	if (ARCH_SUN4C && len > 0x20000000)
 		return -ENOMEM;
 	if (!addr)
 		addr = TASK_UNMAPPED_BASE;

 	if (flags & MAP_SHARED)
 		addr = COLOUR_ALIGN(addr);
 	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 (ARCH_SUN4C && addr < 0xe0000000 && 0x20000000 - len < addr) {
 			addr = PAGE_OFFSET;
 			vmm = find_vma(current->mm, PAGE_OFFSET);
 		}
 		if (TASK_SIZE - PAGE_SIZE - len < addr)
 			return -ENOMEM;
 		if (!vmm || addr + len <= vmm->vm_start)
 			return addr;
 		addr = vmm->vm_end;
 		if (flags & MAP_SHARED)
 			addr = COLOUR_ALIGN(addr);
 	}
 }

 asmlinkage unsigned long sparc_brk(unsigned long brk)
 {
 	if(ARCH_SUN4C) {
 		if ((brk & 0xe0000000) != (current->mm->brk & 0xe0000000))
 			return current->mm->brk;
 	}
 	return sys_brk(brk);
 }

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

 	error = do_pipe_flags(fd, 0);
 	if (error)
 		goto out;
 	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.
  */

 asmlinkage int sys_ipc (uint call, int first, int second, int third, void __user *ptr, long fifth)
 {
 	int version, err;

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

 	if (call <= SEMCTL)
 		switch (call) {
 		case SEMOP:
 			err = sys_semtimedop (first, (struct sembuf __user *)ptr, second, NULL);
 			goto out;
 		case SEMTIMEDOP:
 			err = sys_semtimedop (first, (struct sembuf __user *)ptr, second, (const struct timespec __user *) fifth);
 			goto out;
 		case SEMGET:
 			err = sys_semget (first, second, third);
 			goto out;
 		case SEMCTL: {
 			union semun fourth;
 			err = -EINVAL;
 			if (!ptr)
 				goto out;
 			err = -EFAULT;
 			if (get_user(fourth.__pad,
 				     (void __user * __user *)ptr))
 				goto out;
 			err = sys_semctl (first, second, third, fourth);
 			goto out;
 			}
 		default:
 			err = -ENOSYS;
 			goto out;
 		}
 	if (call <= MSGCTL)
 		switch (call) {
 		case MSGSND:
 			err = sys_msgsnd (first, (struct msgbuf __user *) ptr,
 					  second, third);
 			goto out;
 		case MSGRCV:
 			switch (version) {
 			case 0: {
 				struct ipc_kludge tmp;
 				err = -EINVAL;
 				if (!ptr)
 					goto out;
 				err = -EFAULT;
 				if (copy_from_user(&tmp, (struct ipc_kludge __user *) ptr, sizeof (tmp)))
 					goto out;
 				err = sys_msgrcv (first, tmp.msgp, second, tmp.msgtyp, third);
 				goto out;
 				}
 			case 1: default:
 				err = sys_msgrcv (first,
 						  (struct msgbuf __user *) ptr,
 						  second, fifth, third);
 				goto out;
 			}
 		case MSGGET:
 			err = sys_msgget ((key_t) first, second);
 			goto out;
 		case MSGCTL:
 			err = sys_msgctl (first, second, (struct msqid_ds __user *) ptr);
 			goto out;
 		default:
 			err = -ENOSYS;
 			goto out;
 		}
 	if (call <= SHMCTL)
 		switch (call) {
 		case SHMAT:
 			switch (version) {
 			case 0: default: {
 				ulong raddr;
 				err = do_shmat (first, (char __user *) ptr, second, &raddr);
 				if (err)
 					goto out;
 				err = -EFAULT;
 				if (put_user (raddr, (ulong __user *) third))
 					goto out;
 				err = 0;
 				goto out;
 				}
 			case 1:	/* iBCS2 emulator entry point */
 				err = -EINVAL;
 				goto out;
 			}
 		case SHMDT:
 			err = sys_shmdt ((char __user *)ptr);
 			goto out;
 		case SHMGET:
 			err = sys_shmget (first, second, third);
 			goto out;
 		case SHMCTL:
 			err = sys_shmctl (first, second, (struct shmid_ds __user *) ptr);
 			goto out;
 		default:
 			err = -ENOSYS;
 			goto out;
 		}
 	else
 		err = -ENOSYS;
 out:
 	return err;
 }

 int sparc_mmap_check(unsigned long addr, unsigned long len)
 {
 	if (ARCH_SUN4C &&
 	    (len > 0x20000000 ||
 	     (addr < 0xe0000000 && addr + len > 0x20000000)))
 		return -EINVAL;

 	/* See asm-sparc/uaccess.h */
 	if (len > TASK_SIZE - PAGE_SIZE || addr + len > TASK_SIZE - PAGE_SIZE)
 		return -EINVAL;

 	return 0;
 }

 /* Linux version of mmap */
 static unsigned long do_mmap2(unsigned long addr, unsigned long len,
 	unsigned long prot, unsigned long flags, unsigned long fd,
 	unsigned long pgoff)
 {
 	struct file * file = NULL;
 	unsigned long retval = -EBADF;

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

 	len = PAGE_ALIGN(len);
 	flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);

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

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

 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 do_mmap2(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 off)
 {
 	return do_mmap2(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
 }

 long sparc_remap_file_pages(unsigned long start, unsigned long size,
 			   unsigned long prot, unsigned long pgoff,
 			   unsigned long flags)
 {
 	/* This works on an existing mmap so we don't need to validate
 	 * the range as that was done at the original mmap call.
 	 */
 	return sys_remap_file_pages(start, size, prot,
 				    (pgoff >> (PAGE_SHIFT - 12)), flags);
 }

 extern unsigned long do_mremap(unsigned long addr,
 	unsigned long old_len, unsigned long new_len,
 	unsigned long flags, unsigned long new_addr);

 asmlinkage unsigned long sparc_mremap(unsigned long addr,
 	unsigned long old_len, unsigned long new_len,
 	unsigned long flags, unsigned long new_addr)
 {
 	unsigned long ret = -EINVAL;

 	if (unlikely(sparc_mmap_check(addr, old_len)))
 		goto out;
 	if (unlikely(sparc_mmap_check(new_addr, new_len)))
 		goto out;
 	down_write(&current->mm->mmap_sem);
 	ret = do_mremap(addr, old_len, new_len, flags, new_addr);
 	up_write(&current->mm->mmap_sem);
 out:
 	return ret;
 }

 /* we come to here via sys_nis_syscall so it can setup the regs argument */
 asmlinkage unsigned long
 c_sys_nis_syscall (struct pt_regs *regs)
 {
 	static int count = 0;

 	if (count++ > 5)
 		return -ENOSYS;
 	printk ("%s[%d]: Unimplemented SPARC system call %d\n",
 		current->comm, task_pid_nr(current), (int)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)
 {
 	siginfo_t info;

 	lock_kernel();
 #ifdef DEBUG_SPARC_BREAKPOINT
         printk ("TRAP: Entering kernel PC=%x, nPC=%x\n", regs->pc, regs->npc);
 #endif
 	info.si_signo = SIGTRAP;
 	info.si_errno = 0;
 	info.si_code = TRAP_BRKPT;
 	info.si_addr = (void __user *)regs->pc;
 	info.si_trapno = 0;
 	force_sig_info(SIGTRAP, &info, current);

 #ifdef DEBUG_SPARC_BREAKPOINT
 	printk ("TRAP: Returning to space: PC=%x nPC=%x\n", regs->pc, regs->npc);
 #endif
 	unlock_kernel();
 }

 asmlinkage int
 sparc_sigaction (int sig, const struct old_sigaction __user *act,
 		 struct old_sigaction __user *oact)
 {
 	struct k_sigaction new_ka, old_ka;
 	int ret;

 	WARN_ON_ONCE(sig >= 0);
 	sig = -sig;

 	if (act) {
 		unsigned long mask;

 		if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
 		    __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
 		    __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
 			return -EFAULT;
 		__get_user(new_ka.sa.sa_flags, &act->sa_flags);
 		__get_user(mask, &act->sa_mask);
 		siginitset(&new_ka.sa.sa_mask, mask);
 		new_ka.ka_restorer = NULL;
 	}

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

 	if (!ret && oact) {
 		/* In the clone() case we could copy half consistent
 		 * state to the user, however this could sleep and
 		 * deadlock us if we held the signal lock on SMP.  So for
 		 * now I take the easy way out and do no locking.
 		 */
 		if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
 		    __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
 		    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
 			return -EFAULT;
 		__put_user(old_ka.sa.sa_flags, &oact->sa_flags);
 		__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
 	}

 	return ret;
 }

 asmlinkage long
 sys_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;
 }

 asmlinkage int sys_getdomainname(char __user *name, int len)
 {
  	int nlen, err;

 	if (len < 0)
 		return -EINVAL;

  	down_read(&uts_sem);

 	nlen = strlen(utsname()->domainname) + 1;
 	err = -EINVAL;
 	if (nlen > len)
 		goto out;

 	err = -EFAULT;
 	if (!copy_to_user(name, utsname()->domainname, nlen))
 		err = 0;

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

 /*
  * 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[])
 {
 	long __res;
 	register long __g1 __asm__ ("g1") = __NR_execve;
 	register long __o0 __asm__ ("o0") = (long)(filename);
 	register long __o1 __asm__ ("o1") = (long)(argv);
 	register long __o2 __asm__ ("o2") = (long)(envp);
 	asm volatile ("t 0x10\n\t"
 		      "bcc 1f\n\t"
 		      "mov %%o0, %0\n\t"
 		      "sub %%g0, %%o0, %0\n\t"
 		      "1:\n\t"
 		      : "=r" (__res), "=&r" (__o0)
 		      : "1" (__o0), "r" (__o1), "r" (__o2), "r" (__g1)
 		      : "cc");
 	return __res;
 }
	/* linux/arch/sparc/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.h>
	#include <linux/mm.h>
	#include <linux/fs.h>
	#include <linux/file.h>
	#include <linux/sem.h>
	#include <linux/msg.h>
	#include <linux/shm.h>
	#include <linux/stat.h>
	#include <linux/syscalls.h>
	#include <linux/mman.h>
	#include <linux/utsname.h>
	#include <linux/smp.h>
	#include <linux/smp_lock.h>
	#include <linux/ipc.h>

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

	/* #define DEBUG_UNIMP_SYSCALL */

	/* XXX Make this per-binary type, this way we can detect the type of
	* XXX a binary. Every Sparc executable calls this very early on.
	*/
	asmlinkage unsigned long sys_getpagesize(void)
	{
	return PAGE_SIZE; /* Possibly older binaries want 8192 on sun4's? */
	}

	#define COLOUR_ALIGN(addr) (((addr)+SHMLBA-1)&~(SHMLBA-1))

	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;

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

	/* See asm-sparc/uaccess.h */
	if (len > TASK_SIZE - PAGE_SIZE)
	return -ENOMEM;
	if (ARCH_SUN4C && len > 0x20000000)
	return -ENOMEM;
	if (!addr)
	addr = TASK_UNMAPPED_BASE;

	if (flags & MAP_SHARED)
	addr = COLOUR_ALIGN(addr);
	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 (ARCH_SUN4C && addr < 0xe0000000 && 0x20000000 - len < addr) {
	addr = PAGE_OFFSET;
	vmm = find_vma(current->mm, PAGE_OFFSET);
	}
	if (TASK_SIZE - PAGE_SIZE - len < addr)
	return -ENOMEM;
	if (!vmm \|\| addr + len <= vmm->vm_start)
	return addr;
	addr = vmm->vm_end;
	if (flags & MAP_SHARED)
	addr = COLOUR_ALIGN(addr);
	}
	}

	asmlinkage unsigned long sparc_brk(unsigned long brk)
	{
	if(ARCH_SUN4C) {
	if ((brk & 0xe0000000) != (current->mm->brk & 0xe0000000))
	return current->mm->brk;
	}
	return sys_brk(brk);
	}

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

	error = do_pipe_flags(fd, 0);
	if (error)
	goto out;
	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.
	*/

	asmlinkage int sys_ipc (uint call, int first, int second, int third, void __user *ptr, long fifth)
	{
	int version, err;

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

	if (call <= SEMCTL)
	switch (call) {
	case SEMOP:
	err = sys_semtimedop (first, (struct sembuf __user *)ptr, second, NULL);
	goto out;
	case SEMTIMEDOP:
	err = sys_semtimedop (first, (struct sembuf __user )ptr, second, (const struct timespec __user ) fifth);
	goto out;
	case SEMGET:
	err = sys_semget (first, second, third);
	goto out;
	case SEMCTL: {
	union semun fourth;
	err = -EINVAL;
	if (!ptr)
	goto out;
	err = -EFAULT;
	if (get_user(fourth.__pad,
	(void __user * __user *)ptr))
	goto out;
	err = sys_semctl (first, second, third, fourth);
	goto out;
	}
	default:
	err = -ENOSYS;
	goto out;
	}
	if (call <= MSGCTL)
	switch (call) {
	case MSGSND:
	err = sys_msgsnd (first, (struct msgbuf __user *) ptr,
	second, third);
	goto out;
	case MSGRCV:
	switch (version) {
	case 0: {
	struct ipc_kludge tmp;
	err = -EINVAL;
	if (!ptr)
	goto out;
	err = -EFAULT;
	if (copy_from_user(&tmp, (struct ipc_kludge __user *) ptr, sizeof (tmp)))
	goto out;
	err = sys_msgrcv (first, tmp.msgp, second, tmp.msgtyp, third);
	goto out;
	}
	case 1: default:
	err = sys_msgrcv (first,
	(struct msgbuf __user *) ptr,
	second, fifth, third);
	goto out;
	}
	case MSGGET:
	err = sys_msgget ((key_t) first, second);
	goto out;
	case MSGCTL:
	err = sys_msgctl (first, second, (struct msqid_ds __user *) ptr);
	goto out;
	default:
	err = -ENOSYS;
	goto out;
	}
	if (call <= SHMCTL)
	switch (call) {
	case SHMAT:
	switch (version) {
	case 0: default: {
	ulong raddr;
	err = do_shmat (first, (char __user *) ptr, second, &raddr);
	if (err)
	goto out;
	err = -EFAULT;
	if (put_user (raddr, (ulong __user *) third))
	goto out;
	err = 0;
	goto out;
	}
	case 1: /* iBCS2 emulator entry point */
	err = -EINVAL;
	goto out;
	}
	case SHMDT:
	err = sys_shmdt ((char __user *)ptr);
	goto out;
	case SHMGET:
	err = sys_shmget (first, second, third);
	goto out;
	case SHMCTL:
	err = sys_shmctl (first, second, (struct shmid_ds __user *) ptr);
	goto out;
	default:
	err = -ENOSYS;
	goto out;
	}
	else
	err = -ENOSYS;
	out:
	return err;
	}

	int sparc_mmap_check(unsigned long addr, unsigned long len)
	{
	if (ARCH_SUN4C &&
	(len > 0x20000000 \|\|
	(addr < 0xe0000000 && addr + len > 0x20000000)))
	return -EINVAL;

	/* See asm-sparc/uaccess.h */
	if (len > TASK_SIZE - PAGE_SIZE \|\| addr + len > TASK_SIZE - PAGE_SIZE)
	return -EINVAL;

	return 0;
	}

	/* Linux version of mmap */
	static unsigned long do_mmap2(unsigned long addr, unsigned long len,
	unsigned long prot, unsigned long flags, unsigned long fd,
	unsigned long pgoff)
	{
	struct file * file = NULL;
	unsigned long retval = -EBADF;

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

	len = PAGE_ALIGN(len);
	flags &= ~(MAP_EXECUTABLE \| MAP_DENYWRITE);

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

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

	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 do_mmap2(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 off)
	{
	return do_mmap2(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
	}

	long sparc_remap_file_pages(unsigned long start, unsigned long size,
	unsigned long prot, unsigned long pgoff,
	unsigned long flags)
	{
	/* This works on an existing mmap so we don't need to validate
	* the range as that was done at the original mmap call.
	*/
	return sys_remap_file_pages(start, size, prot,
	(pgoff >> (PAGE_SHIFT - 12)), flags);
	}

	extern unsigned long do_mremap(unsigned long addr,
	unsigned long old_len, unsigned long new_len,
	unsigned long flags, unsigned long new_addr);

	asmlinkage unsigned long sparc_mremap(unsigned long addr,
	unsigned long old_len, unsigned long new_len,
	unsigned long flags, unsigned long new_addr)
	{
	unsigned long ret = -EINVAL;

	if (unlikely(sparc_mmap_check(addr, old_len)))
	goto out;
	if (unlikely(sparc_mmap_check(new_addr, new_len)))
	goto out;
	down_write(&current->mm->mmap_sem);
	ret = do_mremap(addr, old_len, new_len, flags, new_addr);
	up_write(&current->mm->mmap_sem);
	out:
	return ret;
	}

	/* we come to here via sys_nis_syscall so it can setup the regs argument */
	asmlinkage unsigned long
	c_sys_nis_syscall (struct pt_regs *regs)
	{
	static int count = 0;

	if (count++ > 5)
	return -ENOSYS;
	printk ("%s[%d]: Unimplemented SPARC system call %d\n",
	current->comm, task_pid_nr(current), (int)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)
	{
	siginfo_t info;

	lock_kernel();
	#ifdef DEBUG_SPARC_BREAKPOINT
	printk ("TRAP: Entering kernel PC=%x, nPC=%x\n", regs->pc, regs->npc);
	#endif
	info.si_signo = SIGTRAP;
	info.si_errno = 0;
	info.si_code = TRAP_BRKPT;
	info.si_addr = (void __user *)regs->pc;
	info.si_trapno = 0;
	force_sig_info(SIGTRAP, &info, current);

	#ifdef DEBUG_SPARC_BREAKPOINT
	printk ("TRAP: Returning to space: PC=%x nPC=%x\n", regs->pc, regs->npc);
	#endif
	unlock_kernel();
	}

	asmlinkage int
	sparc_sigaction (int sig, const struct old_sigaction __user *act,
	struct old_sigaction __user *oact)
	{
	struct k_sigaction new_ka, old_ka;
	int ret;

	WARN_ON_ONCE(sig >= 0);
	sig = -sig;

	if (act) {
	unsigned long mask;

	if (!access_ok(VERIFY_READ, act, sizeof(*act)) \|\|
	__get_user(new_ka.sa.sa_handler, &act->sa_handler) \|\|
	__get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
	return -EFAULT;
	__get_user(new_ka.sa.sa_flags, &act->sa_flags);
	__get_user(mask, &act->sa_mask);
	siginitset(&new_ka.sa.sa_mask, mask);
	new_ka.ka_restorer = NULL;
	}

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

	if (!ret && oact) {
	/* In the clone() case we could copy half consistent
	* state to the user, however this could sleep and
	* deadlock us if we held the signal lock on SMP. So for
	* now I take the easy way out and do no locking.
	*/
	if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) \|\|
	__put_user(old_ka.sa.sa_handler, &oact->sa_handler) \|\|
	__put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
	return -EFAULT;
	__put_user(old_ka.sa.sa_flags, &oact->sa_flags);
	__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
	}

	return ret;
	}

	asmlinkage long
	sys_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;
	}

	asmlinkage int sys_getdomainname(char __user *name, int len)
	{
	int nlen, err;

	if (len < 0)
	return -EINVAL;

	down_read(&uts_sem);

	nlen = strlen(utsname()->domainname) + 1;
	err = -EINVAL;
	if (nlen > len)
	goto out;

	err = -EFAULT;
	if (!copy_to_user(name, utsname()->domainname, nlen))
	err = 0;

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

	/*
	* 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[])
	{
	long __res;
	register long __g1 __asm__ ("g1") = __NR_execve;
	register long __o0 __asm__ ("o0") = (long)(filename);
	register long __o1 __asm__ ("o1") = (long)(argv);
	register long __o2 __asm__ ("o2") = (long)(envp);
	asm volatile ("t 0x10\n\t"
	"bcc 1f\n\t"
	"mov %%o0, %0\n\t"
	"sub %%g0, %%o0, %0\n\t"
	"1:\n\t"
	: "=r" (__res), "=&r" (__o0)
	: "1" (__o0), "r" (__o1), "r" (__o2), "r" (__g1)
	: "cc");
	return __res;
	}