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