arch/sparc/kernel/sys_sparc_64.c - third_party/linux - Git at Google

 // 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/uaccess.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;
 }

 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long 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;

 	if (flags & MAP_FIXED) {
 		/* We do not accept a shared mapping if it would violate
 		 * cache aliasing constraints.
 		 */
 		if ((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))
 		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.flags = 0;
 	info.length = len;
 	info.low_limit = TASK_UNMAPPED_BASE;
 	info.high_limit = min(task_size, VA_EXCLUDE_START);
 	info.align_mask = do_color_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
 	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)
 {
 	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;

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

 	if (flags & MAP_FIXED) {
 		/* We do not accept a shared mapping if it would violate
 		 * cache aliasing constraints.
 		 */
 		if ((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))
 		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 = do_color_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
 	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;
 	unsigned long (*get_area)(struct file *, unsigned long,
 				  unsigned long, unsigned long, unsigned long);

 	get_area = current->mm->get_unmapped_area;

 	if (flags & MAP_FIXED) {
 		/* Ok, don't mess with it. */
 		return get_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 = get_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 = get_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, 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->get_unmapped_area = arch_get_unmapped_area;
 	} 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->get_unmapped_area = arch_get_unmapped_area_topdown;
 	}
 }

 /*
  * 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;

 	/* No need for backward compatibility. We can start fresh... */
 	if (call <= SEMTIMEDOP) {
 		switch (call) {
 		case SEMOP:
 			err = sys_semtimedop(first, ptr,
 					     (unsigned int)second, NULL);
 			goto out;
 		case SEMTIMEDOP:
 			err = sys_semtimedop(first, ptr, (unsigned int)second,
 				(const struct timespec __user *)
 					     (unsigned long) fifth);
 			goto out;
 		case SEMGET:
 			err = sys_semget(first, (int)second, (int)third);
 			goto out;
 		case SEMCTL: {
 			err = sys_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 = sys_msgsnd(first, ptr, (size_t)second,
 					 (int)third);
 			goto out;
 		case MSGRCV:
 			err = sys_msgrcv(first, ptr, (size_t)second, fifth,
 					 (int)third);
 			goto out;
 		case MSGGET:
 			err = sys_msgget((key_t)first, (int)second);
 			goto out;
 		case MSGCTL:
 			err = sys_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 = sys_shmdt(ptr);
 			goto out;
 		case SHMGET:
 			err = sys_shmget(first, (size_t)second, (int)third);
 			goto out;
 		case SHMCTL:
 			err = sys_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, 0, current);
 #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;

 	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;
 }

 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 =
 			kcalloc(UT_TRAP_INSTRUCTION_31 + 1, sizeof(long),
 				GFP_KERNEL);
 		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_array(UT_TRAP_INSTRUCTION_31 + 1,
 					      sizeof(long),
 					      GFP_KERNEL);
 			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;
 }
	// 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/uaccess.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;
	}

	unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long 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;

	if (flags & MAP_FIXED) {
	/* We do not accept a shared mapping if it would violate
	* cache aliasing constraints.
	*/
	if ((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))
	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.flags = 0;
	info.length = len;
	info.low_limit = TASK_UNMAPPED_BASE;
	info.high_limit = min(task_size, VA_EXCLUDE_START);
	info.align_mask = do_color_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
	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)
	{
	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;

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

	if (flags & MAP_FIXED) {
	/* We do not accept a shared mapping if it would violate
	* cache aliasing constraints.
	*/
	if ((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))
	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 = do_color_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
	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;
	unsigned long (get_area)(struct file , unsigned long,
	unsigned long, unsigned long, unsigned long);

	get_area = current->mm->get_unmapped_area;

	if (flags & MAP_FIXED) {
	/* Ok, don't mess with it. */
	return get_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 = get_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 = get_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, 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->get_unmapped_area = arch_get_unmapped_area;
	} 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->get_unmapped_area = arch_get_unmapped_area_topdown;
	}
	}

	/*
	* 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;

	/* No need for backward compatibility. We can start fresh... */
	if (call <= SEMTIMEDOP) {
	switch (call) {
	case SEMOP:
	err = sys_semtimedop(first, ptr,
	(unsigned int)second, NULL);
	goto out;
	case SEMTIMEDOP:
	err = sys_semtimedop(first, ptr, (unsigned int)second,
	(const struct timespec __user *)
	(unsigned long) fifth);
	goto out;
	case SEMGET:
	err = sys_semget(first, (int)second, (int)third);
	goto out;
	case SEMCTL: {
	err = sys_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 = sys_msgsnd(first, ptr, (size_t)second,
	(int)third);
	goto out;
	case MSGRCV:
	err = sys_msgrcv(first, ptr, (size_t)second, fifth,
	(int)third);
	goto out;
	case MSGGET:
	err = sys_msgget((key_t)first, (int)second);
	goto out;
	case MSGCTL:
	err = sys_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 = sys_shmdt(ptr);
	goto out;
	case SHMGET:
	err = sys_shmget(first, (size_t)second, (int)third);
	goto out;
	case SHMCTL:
	err = sys_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, 0, current);
	#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;

	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;
	}

	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 =
	kcalloc(UT_TRAP_INSTRUCTION_31 + 1, sizeof(long),
	GFP_KERNEL);
	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_array(UT_TRAP_INSTRUCTION_31 + 1,
	sizeof(long),
	GFP_KERNEL);
	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;
	}