arch/arc/mm/mmap.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * ARC700 mmap
   4  *
   5  * (started from arm version - for VIPT alias handling)
   6  *
   7  * Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com)
   8  */
   9
  10 #include <linux/fs.h>
  11 #include <linux/mm.h>
  12 #include <linux/mman.h>
  13 #include <linux/sched/mm.h>
  14
  15 #include <asm/cacheflush.h>
  16
  17 /*
  18  * Ensure that shared mappings are correctly aligned to
  19  * avoid aliasing issues with VIPT caches.
  20  * We need to ensure that
  21  * a specific page of an object is always mapped at a multiple of
  22  * SHMLBA bytes.
  23  */
  24 unsigned long
  25 arch_get_unmapped_area(struct file *filp, unsigned long addr,
  26                 unsigned long len, unsigned long pgoff, unsigned long flags)
  27 {
  28         struct mm_struct *mm = current->mm;
  29         struct vm_area_struct *vma;
  30         struct vm_unmapped_area_info info = {};
  31
  32         /*
  33          * We enforce the MAP_FIXED case.
  34          */
  35         if (flags & MAP_FIXED) {
  36                 if (flags & MAP_SHARED &&
  37                     (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
  38                         return -EINVAL;
  39                 return addr;
  40         }
  41
  42         if (len > TASK_SIZE)
  43                 return -ENOMEM;
  44
  45         if (addr) {
  46                 addr = PAGE_ALIGN(addr);
  47
  48                 vma = find_vma(mm, addr);
  49                 if (TASK_SIZE - len >= addr &&
  50                     (!vma || addr + len <= vm_start_gap(vma)))
  51                         return addr;
  52         }
  53
  54         info.length = len;
  55         info.low_limit = mm->mmap_base;
  56         info.high_limit = TASK_SIZE;
  57         info.align_offset = pgoff << PAGE_SHIFT;
  58         return vm_unmapped_area(&info);
  59 }
  60
  61 static const pgprot_t protection_map[16] = {
  62         [VM_NONE]                                       = PAGE_U_NONE,
  63         [VM_READ]                                       = PAGE_U_R,
  64         [VM_WRITE]                                      = PAGE_U_R,
  65         [VM_WRITE | VM_READ]                            = PAGE_U_R,
  66         [VM_EXEC]                                       = PAGE_U_X_R,
  67         [VM_EXEC | VM_READ]                             = PAGE_U_X_R,
  68         [VM_EXEC | VM_WRITE]                            = PAGE_U_X_R,
  69         [VM_EXEC | VM_WRITE | VM_READ]                  = PAGE_U_X_R,
  70         [VM_SHARED]                                     = PAGE_U_NONE,
  71         [VM_SHARED | VM_READ]                           = PAGE_U_R,
  72         [VM_SHARED | VM_WRITE]                          = PAGE_U_W_R,
  73         [VM_SHARED | VM_WRITE | VM_READ]                = PAGE_U_W_R,
  74         [VM_SHARED | VM_EXEC]                           = PAGE_U_X_R,
  75         [VM_SHARED | VM_EXEC | VM_READ]                 = PAGE_U_X_R,
  76         [VM_SHARED | VM_EXEC | VM_WRITE]                = PAGE_U_X_W_R,
  77         [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]      = PAGE_U_X_W_R
  78 };
  79 DECLARE_VM_GET_PAGE_PROT