LXR linux/arch/xtensa/kernel/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 <asm/unistd.h>
  21#include <linux/linkage.h>
  22#include <linux/stringify.h>
  23#include <linux/errno.h>
  24#include <linux/syscalls.h>
  25#include <linux/file.h>
  26#include <linux/fs.h>
  27#include <linux/mman.h>
  28#include <linux/sched/mm.h>
  29#include <linux/shm.h>
  30
  31typedef void (*syscall_t)(void);
  32
  33syscall_t sys_call_table[__NR_syscall_count] /* FIXME __cacheline_aligned */= {
  34        [0 ... __NR_syscall_count - 1] = (syscall_t)&sys_ni_syscall,
  35
  36#define __SYSCALL(nr,symbol,nargs) [ nr ] = (syscall_t)symbol,
  37#include <uapi/asm/unistd.h>
  38};
  39
  40#define COLOUR_ALIGN(addr, pgoff) \
  41        ((((addr) + SHMLBA - 1) & ~(SHMLBA - 1)) + \
  42         (((pgoff) << PAGE_SHIFT) & (SHMLBA - 1)))
  43
  44asmlinkage long xtensa_shmat(int shmid, char __user *shmaddr, int shmflg)
  45{
  46        unsigned long ret;
  47        long err;
  48
  49        err = do_shmat(shmid, shmaddr, shmflg, &ret, SHMLBA);
  50        if (err)
  51                return err;
  52        return (long)ret;
  53}
  54
  55asmlinkage long xtensa_fadvise64_64(int fd, int advice,
  56                unsigned long long offset, unsigned long long len)
  57{
  58        return ksys_fadvise64_64(fd, offset, len, advice);
  59}
  60
  61#ifdef CONFIG_MMU
  62unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
  63                unsigned long len, unsigned long pgoff, unsigned long flags)
  64{
  65        struct vm_area_struct *vmm;
  66
  67        if (flags & MAP_FIXED) {
  68                /* We do not accept a shared mapping if it would violate
  69                 * cache aliasing constraints.
  70                 */
  71                if ((flags & MAP_SHARED) &&
  72                                ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
  73                        return -EINVAL;
  74                return addr;
  75        }
  76
  77        if (len > TASK_SIZE)
  78                return -ENOMEM;
  79        if (!addr)
  80                addr = TASK_UNMAPPED_BASE;
  81
  82        if (flags & MAP_SHARED)
  83                addr = COLOUR_ALIGN(addr, pgoff);
  84        else
  85                addr = PAGE_ALIGN(addr);
  86
  87        for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
  88                /* At this point:  (!vmm || addr < vmm->vm_end). */
  89                if (TASK_SIZE - len < addr)
  90                        return -ENOMEM;
  91                if (!vmm || addr + len <= vm_start_gap(vmm))
  92                        return addr;
  93                addr = vmm->vm_end;
  94                if (flags & MAP_SHARED)
  95                        addr = COLOUR_ALIGN(addr, pgoff);
  96        }
  97}
  98#endif
  99