1 // SPDX-License-Identifier: GPL-2.0 2 3 #include <linux/mm.h> 4 #include <linux/file.h> 5 #include <linux/fdtable.h> 6 #include <linux/fs_struct.h> 7 #include <linux/mount.h> 8 #include <linux/ptrace.h> 9 #include <linux/slab.h> 10 #include <linux/seq_file.h> 11 #include <linux/sched/mm.h> 12 13 #include "internal.h" 14 15 /* 16 * Logic: we've got two memory sums for each process, "shared", and 17 * "non-shared". Shared memory may get counted more than once, for 18 * each process that owns it. Non-shared memory is counted 19 * accurately. 20 */ 21 void task_mem(struct seq_file *m, struct mm_struct *mm) 22 { 23 VMA_ITERATOR(vmi, mm, 0); 24 struct vm_area_struct *vma; 25 struct vm_region *region; 26 unsigned long bytes = 0, sbytes = 0, slack = 0, size; 27 28 mmap_read_lock(mm); 29 for_each_vma(vmi, vma) { 30 bytes += kobjsize(vma); 31 32 region = vma->vm_region; 33 if (region) { 34 size = kobjsize(region); 35 size += region->vm_end - region->vm_start; 36 } else { 37 size = vma->vm_end - vma->vm_start; 38 } 39 40 if (atomic_read(&mm->mm_count) > 1 || 41 is_nommu_shared_mapping(vma->vm_flags)) { 42 sbytes += size; 43 } else { 44 bytes += size; 45 if (region) 46 slack = region->vm_end - vma->vm_end; 47 } 48 } 49 50 if (atomic_read(&mm->mm_count) > 1) 51 sbytes += kobjsize(mm); 52 else 53 bytes += kobjsize(mm); 54 55 if (current->fs && current->fs->users > 1) 56 sbytes += kobjsize(current->fs); 57 else 58 bytes += kobjsize(current->fs); 59 60 if (current->files && atomic_read(¤t->files->count) > 1) 61 sbytes += kobjsize(current->files); 62 else 63 bytes += kobjsize(current->files); 64 65 if (current->sighand && refcount_read(¤t->sighand->count) > 1) 66 sbytes += kobjsize(current->sighand); 67 else 68 bytes += kobjsize(current->sighand); 69 70 bytes += kobjsize(current); /* includes kernel stack */ 71 72 mmap_read_unlock(mm); 73 74 seq_printf(m, 75 "Mem:\t%8lu bytes\n" 76 "Slack:\t%8lu bytes\n" 77 "Shared:\t%8lu bytes\n", 78 bytes, slack, sbytes); 79 } 80 81 unsigned long task_vsize(struct mm_struct *mm) 82 { 83 VMA_ITERATOR(vmi, mm, 0); 84 struct vm_area_struct *vma; 85 unsigned long vsize = 0; 86 87 mmap_read_lock(mm); 88 for_each_vma(vmi, vma) 89 vsize += vma->vm_end - vma->vm_start; 90 mmap_read_unlock(mm); 91 return vsize; 92 } 93 94 unsigned long task_statm(struct mm_struct *mm, 95 unsigned long *shared, unsigned long *text, 96 unsigned long *data, unsigned long *resident) 97 { 98 VMA_ITERATOR(vmi, mm, 0); 99 struct vm_area_struct *vma; 100 struct vm_region *region; 101 unsigned long size = kobjsize(mm); 102 103 mmap_read_lock(mm); 104 for_each_vma(vmi, vma) { 105 size += kobjsize(vma); 106 region = vma->vm_region; 107 if (region) { 108 size += kobjsize(region); 109 size += region->vm_end - region->vm_start; 110 } 111 } 112 113 *text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) 114 >> PAGE_SHIFT; 115 *data = (PAGE_ALIGN(mm->start_stack) - (mm->start_data & PAGE_MASK)) 116 >> PAGE_SHIFT; 117 mmap_read_unlock(mm); 118 size >>= PAGE_SHIFT; 119 size += *text + *data; 120 *resident = size; 121 return size; 122 } 123 124 /* 125 * display a single VMA to a sequenced file 126 */ 127 static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma) 128 { 129 struct mm_struct *mm = vma->vm_mm; 130 unsigned long ino = 0; 131 struct file *file; 132 dev_t dev = 0; 133 int flags; 134 unsigned long long pgoff = 0; 135 136 flags = vma->vm_flags; 137 file = vma->vm_file; 138 139 if (file) { 140 struct inode *inode = file_inode(vma->vm_file); 141 dev = inode->i_sb->s_dev; 142 ino = inode->i_ino; 143 pgoff = (loff_t)vma->vm_pgoff << PAGE_SHIFT; 144 } 145 146 seq_setwidth(m, 25 + sizeof(void *) * 6 - 1); 147 seq_printf(m, 148 "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ", 149 vma->vm_start, 150 vma->vm_end, 151 flags & VM_READ ? 'r' : '-', 152 flags & VM_WRITE ? 'w' : '-', 153 flags & VM_EXEC ? 'x' : '-', 154 flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p', 155 pgoff, 156 MAJOR(dev), MINOR(dev), ino); 157 158 if (file) { 159 seq_pad(m, ' '); 160 seq_file_path(m, file, ""); 161 } else if (mm && vma_is_initial_stack(vma)) { 162 seq_pad(m, ' '); 163 seq_puts(m, "[stack]"); 164 } 165 166 seq_putc(m, '\n'); 167 return 0; 168 } 169 170 /* 171 * display mapping lines for a particular process's /proc/pid/maps 172 */ 173 static int show_map(struct seq_file *m, void *_p) 174 { 175 return nommu_vma_show(m, _p); 176 } 177 178 static void *m_start(struct seq_file *m, loff_t *pos) 179 { 180 struct proc_maps_private *priv = m->private; 181 struct mm_struct *mm; 182 struct vm_area_struct *vma; 183 unsigned long addr = *pos; 184 185 /* See m_next(). Zero at the start or after lseek. */ 186 if (addr == -1UL) 187 return NULL; 188 189 /* pin the task and mm whilst we play with them */ 190 priv->task = get_proc_task(priv->inode); 191 if (!priv->task) 192 return ERR_PTR(-ESRCH); 193 194 mm = priv->mm; 195 if (!mm || !mmget_not_zero(mm)) { 196 put_task_struct(priv->task); 197 priv->task = NULL; 198 return NULL; 199 } 200 201 if (mmap_read_lock_killable(mm)) { 202 mmput(mm); 203 put_task_struct(priv->task); 204 priv->task = NULL; 205 return ERR_PTR(-EINTR); 206 } 207 208 /* start the next element from addr */ 209 vma = find_vma(mm, addr); 210 if (vma) 211 return vma; 212 213 return NULL; 214 } 215 216 static void m_stop(struct seq_file *m, void *v) 217 { 218 struct proc_maps_private *priv = m->private; 219 struct mm_struct *mm = priv->mm; 220 221 if (!priv->task) 222 return; 223 224 mmap_read_unlock(mm); 225 mmput(mm); 226 put_task_struct(priv->task); 227 priv->task = NULL; 228 } 229 230 static void *m_next(struct seq_file *m, void *_p, loff_t *pos) 231 { 232 struct vm_area_struct *vma = _p; 233 234 *pos = vma->vm_end; 235 return find_vma(vma->vm_mm, vma->vm_end); 236 } 237 238 static const struct seq_operations proc_pid_maps_ops = { 239 .start = m_start, 240 .next = m_next, 241 .stop = m_stop, 242 .show = show_map 243 }; 244 245 static int maps_open(struct inode *inode, struct file *file, 246 const struct seq_operations *ops) 247 { 248 struct proc_maps_private *priv; 249 250 priv = __seq_open_private(file, ops, sizeof(*priv)); 251 if (!priv) 252 return -ENOMEM; 253 254 priv->inode = inode; 255 priv->mm = proc_mem_open(inode, PTRACE_MODE_READ); 256 if (IS_ERR(priv->mm)) { 257 int err = PTR_ERR(priv->mm); 258 259 seq_release_private(inode, file); 260 return err; 261 } 262 263 return 0; 264 } 265 266 267 static int map_release(struct inode *inode, struct file *file) 268 { 269 struct seq_file *seq = file->private_data; 270 struct proc_maps_private *priv = seq->private; 271 272 if (priv->mm) 273 mmdrop(priv->mm); 274 275 return seq_release_private(inode, file); 276 } 277 278 static int pid_maps_open(struct inode *inode, struct file *file) 279 { 280 return maps_open(inode, file, &proc_pid_maps_ops); 281 } 282 283 const struct file_operations proc_pid_maps_operations = { 284 .open = pid_maps_open, 285 .read = seq_read, 286 .llseek = seq_lseek, 287 .release = map_release, 288 }; 289 290