1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* nommu.c: mmu-less memory info files 3 * 4 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. 5 * Written by David Howells (dhowells@redhat.com) 6 */ 7 8 #include <linux/init.h> 9 #include <linux/module.h> 10 #include <linux/errno.h> 11 #include <linux/time.h> 12 #include <linux/kernel.h> 13 #include <linux/string.h> 14 #include <linux/mman.h> 15 #include <linux/proc_fs.h> 16 #include <linux/mm.h> 17 #include <linux/mmzone.h> 18 #include <linux/pagemap.h> 19 #include <linux/swap.h> 20 #include <linux/smp.h> 21 #include <linux/seq_file.h> 22 #include <linux/hugetlb.h> 23 #include <linux/vmalloc.h> 24 #include <linux/uaccess.h> 25 #include <asm/pgtable.h> 26 #include <asm/tlb.h> 27 #include <asm/div64.h> 28 #include "internal.h" 29 30 /* 31 * display a single region to a sequenced file 32 */ 33 static int nommu_region_show(struct seq_file *m, struct vm_region *region) 34 { 35 unsigned long ino = 0; 36 struct file *file; 37 dev_t dev = 0; 38 int flags; 39 40 flags = region->vm_flags; 41 file = region->vm_file; 42 43 if (file) { 44 struct inode *inode = file_inode(region->vm_file); 45 dev = inode->i_sb->s_dev; 46 ino = inode->i_ino; 47 } 48 49 seq_setwidth(m, 25 + sizeof(void *) * 6 - 1); 50 seq_printf(m, 51 "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ", 52 region->vm_start, 53 region->vm_end, 54 flags & VM_READ ? 'r' : '-', 55 flags & VM_WRITE ? 'w' : '-', 56 flags & VM_EXEC ? 'x' : '-', 57 flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p', 58 ((loff_t)region->vm_pgoff) << PAGE_SHIFT, 59 MAJOR(dev), MINOR(dev), ino); 60 61 if (file) { 62 seq_pad(m, ' '); 63 seq_file_path(m, file, ""); 64 } 65 66 seq_putc(m, '\n'); 67 return 0; 68 } 69 70 /* 71 * display a list of all the REGIONs the kernel knows about 72 * - nommu kernels have a single flat list 73 */ 74 static int nommu_region_list_show(struct seq_file *m, void *_p) 75 { 76 struct rb_node *p = _p; 77 78 return nommu_region_show(m, rb_entry(p, struct vm_region, vm_rb)); 79 } 80 81 static void *nommu_region_list_start(struct seq_file *m, loff_t *_pos) 82 { 83 struct rb_node *p; 84 loff_t pos = *_pos; 85 86 down_read(&nommu_region_sem); 87 88 for (p = rb_first(&nommu_region_tree); p; p = rb_next(p)) 89 if (pos-- == 0) 90 return p; 91 return NULL; 92 } 93 94 static void nommu_region_list_stop(struct seq_file *m, void *v) 95 { 96 up_read(&nommu_region_sem); 97 } 98 99 static void *nommu_region_list_next(struct seq_file *m, void *v, loff_t *pos) 100 { 101 (*pos)++; 102 return rb_next((struct rb_node *) v); 103 } 104 105 static const struct seq_operations proc_nommu_region_list_seqop = { 106 .start = nommu_region_list_start, 107 .next = nommu_region_list_next, 108 .stop = nommu_region_list_stop, 109 .show = nommu_region_list_show 110 }; 111 112 static int __init proc_nommu_init(void) 113 { 114 proc_create_seq("maps", S_IRUGO, NULL, &proc_nommu_region_list_seqop); 115 return 0; 116 } 117 118 fs_initcall(proc_nommu_init); 119