syscall.c

  1/*
  2 * arch/xtensa/kernel/syscall.c
  3 *
  4 * This file is subject to the terms and conditions of the GNU General Public
  5 * License.  See the file "COPYING" in the main directory of this archive
  6 * for more details.
  7 *
  8 * Copyright (C) 2001 - 2005 Tensilica Inc.
  9 * Copyright (C) 2000 Silicon Graphics, Inc.
 10 * Copyright (C) 1995 - 2000 by Ralf Baechle
 11 *
 12 * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
 13 * Marc Gauthier <marc@tensilica.com, marc@alumni.uwaterloo.ca>
 14 * Chris Zankel <chris@zankel.net>
 15 * Kevin Chea
 16 *
 17 */
 18#include <linux/uaccess.h>
 19#include <asm/syscall.h>
 20#include <linux/linkage.h>
 21#include <linux/stringify.h>
 22#include <linux/errno.h>
 23#include <linux/syscalls.h>
 24#include <linux/file.h>
 25#include <linux/fs.h>
 26#include <linux/mman.h>
 27#include <linux/sched/mm.h>
 28#include <linux/shm.h>
 29
 30syscall_t sys_call_table[] /* FIXME __cacheline_aligned */= {
 31#define __SYSCALL(nr, entry)	(syscall_t)entry,
 32#include <asm/syscall_table.h>
 33};
 34
 35#define COLOUR_ALIGN(addr, pgoff) \
 36	((((addr) + SHMLBA - 1) & ~(SHMLBA - 1)) + \
 37	 (((pgoff) << PAGE_SHIFT) & (SHMLBA - 1)))
 38
 39asmlinkage long xtensa_shmat(int shmid, char __user *shmaddr, int shmflg)
 40{
 41	unsigned long ret;
 42	long err;
 43
 44	err = do_shmat(shmid, shmaddr, shmflg, &ret, SHMLBA);
 45	if (err)
 46		return err;
 47	return (long)ret;
 48}
 49
 50asmlinkage long xtensa_fadvise64_64(int fd, int advice,
 51		unsigned long long offset, unsigned long long len)
 52{
 53	return ksys_fadvise64_64(fd, offset, len, advice);
 54}
 55
 56#ifdef CONFIG_MMU
 57unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
 58		unsigned long len, unsigned long pgoff, unsigned long flags,
 59		vm_flags_t vm_flags)
 60{
 61	struct vm_area_struct *vmm;
 62	struct vma_iterator vmi;
 63
 64	if (flags & MAP_FIXED) {
 65		/* We do not accept a shared mapping if it would violate
 66		 * cache aliasing constraints.
 67		 */
 68		if ((flags & MAP_SHARED) &&
 69				((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
 70			return -EINVAL;
 71		return addr;
 72	}
 73
 74	if (len > TASK_SIZE)
 75		return -ENOMEM;
 76	if (!addr)
 77		addr = TASK_UNMAPPED_BASE;
 78
 79	if (flags & MAP_SHARED)
 80		addr = COLOUR_ALIGN(addr, pgoff);
 81	else
 82		addr = PAGE_ALIGN(addr);
 83
 84	vma_iter_init(&vmi, current->mm, addr);
 85	for_each_vma(vmi, vmm) {
 86		/* At this point:  (addr < vmm->vm_end). */
 87		if (addr + len <= vm_start_gap(vmm))
 88			break;
 89
 90		addr = vmm->vm_end;
 91		if (flags & MAP_SHARED)
 92			addr = COLOUR_ALIGN(addr, pgoff);
 93	}
 94
 95	if (TASK_SIZE - len < addr)
 96		return -ENOMEM;
 97
 98	return addr;
 99}
100#endif