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 81