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,
  27                 unsigned long flags, vm_flags_t vm_flags)
  28 {
  29         struct mm_struct *mm = current->mm;
  30         struct vm_area_struct *vma;
  31         struct vm_unmapped_area_info info = {};
  32
  33         /*
  34          * We enforce the MAP_FIXED case.
  35          */
  36         if (flags & MAP_FIXED) {
  37                 if (flags & MAP_SHARED &&
  38                     (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
  39                         return -EINVAL;
  40                 return addr;
  41         }
  42
  43         if (len > TASK_SIZE)
  44                 return -ENOMEM;
  45
  46         if (addr) {
  47                 addr = PAGE_ALIGN(addr);
  48
  49                 vma = find_vma(mm, addr);
  50                 if (TASK_SIZE - len >= addr &&
  51                     (!vma || addr + len <= vm_start_gap(vma)))
  52                         return addr;
  53         }
  54
  55         info.length = len;
  56         info.low_limit = mm->mmap_base;
  57         info.high_limit = TASK_SIZE;
  58         info.align_offset = pgoff << PAGE_SHIFT;
  59         return vm_unmapped_area(&info);
  60 }
  61
  62 static const pgprot_t protection_map[16] = {
  63         [VM_NONE]                                       = PAGE_U_NONE,
  64         [VM_READ]                                       = PAGE_U_R,
  65         [VM_WRITE]                                      = PAGE_U_R,
  66         [VM_WRITE | VM_READ]                            = PAGE_U_R,
  67         [VM_EXEC]                                       = PAGE_U_X_R,
  68         [VM_EXEC | VM_READ]                             = PAGE_U_X_R,
  69         [VM_EXEC | VM_WRITE]                            = PAGE_U_X_R,
  70         [VM_EXEC | VM_WRITE | VM_READ]                  = PAGE_U_X_R,
  71         [VM_SHARED]                                     = PAGE_U_NONE,
  72         [VM_SHARED | VM_READ]                           = PAGE_U_R,
  73         [VM_SHARED | VM_WRITE]                          = PAGE_U_W_R,
  74         [VM_SHARED | VM_WRITE | VM_READ]                = PAGE_U_W_R,
  75         [VM_SHARED | VM_EXEC]                           = PAGE_U_X_R,
  76         [VM_SHARED | VM_EXEC | VM_READ]                 = PAGE_U_X_R,
  77         [VM_SHARED | VM_EXEC | VM_WRITE]                = PAGE_U_X_W_R,
  78         [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]      = PAGE_U_X_W_R
  79 };
  80 DECLARE_VM_GET_PAGE_PROT