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_path(m, file_user_path(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 struct vm_area_struct *proc_get_vma(struct proc_maps_private *priv, 179 loff_t *ppos) 180 { 181 struct vm_area_struct *vma = vma_next(&priv->iter); 182 183 if (vma) { 184 *ppos = vma->vm_start; 185 } else { 186 *ppos = -1UL; 187 } 188 189 return vma; 190 } 191 192 static void *m_start(struct seq_file *m, loff_t *ppos) 193 { 194 struct proc_maps_private *priv = m->private; 195 unsigned long last_addr = *ppos; 196 struct mm_struct *mm; 197 198 /* See proc_get_vma(). Zero at the start or after lseek. */ 199 if (last_addr == -1UL) 200 return NULL; 201 202 /* pin the task and mm whilst we play with them */ 203 priv->task = get_proc_task(priv->inode); 204 if (!priv->task) 205 return ERR_PTR(-ESRCH); 206 207 mm = priv->mm; 208 if (!mm || !mmget_not_zero(mm)) { 209 put_task_struct(priv->task); 210 priv->task = NULL; 211 return NULL; 212 } 213 214 if (mmap_read_lock_killable(mm)) { 215 mmput(mm); 216 put_task_struct(priv->task); 217 priv->task = NULL; 218 return ERR_PTR(-EINTR); 219 } 220 221 vma_iter_init(&priv->iter, mm, last_addr); 222 223 return proc_get_vma(priv, ppos); 224 } 225 226 static void m_stop(struct seq_file *m, void *v) 227 { 228 struct proc_maps_private *priv = m->private; 229 struct mm_struct *mm = priv->mm; 230 231 if (!priv->task) 232 return; 233 234 mmap_read_unlock(mm); 235 mmput(mm); 236 put_task_struct(priv->task); 237 priv->task = NULL; 238 } 239 240 static void *m_next(struct seq_file *m, void *_p, loff_t *ppos) 241 { 242 return proc_get_vma(m->private, ppos); 243 } 244 245 static const struct seq_operations proc_pid_maps_ops = { 246 .start = m_start, 247 .next = m_next, 248 .stop = m_stop, 249 .show = show_map 250 }; 251 252 static int maps_open(struct inode *inode, struct file *file, 253 const struct seq_operations *ops) 254 { 255 struct proc_maps_private *priv; 256 257 priv = __seq_open_private(file, ops, sizeof(*priv)); 258 if (!priv) 259 return -ENOMEM; 260 261 priv->inode = inode; 262 priv->mm = proc_mem_open(inode, PTRACE_MODE_READ); 263 if (IS_ERR(priv->mm)) { 264 int err = PTR_ERR(priv->mm); 265 266 seq_release_private(inode, file); 267 return err; 268 } 269 270 return 0; 271 } 272 273 274 static int map_release(struct inode *inode, struct file *file) 275 { 276 struct seq_file *seq = file->private_data; 277 struct proc_maps_private *priv = seq->private; 278 279 if (priv->mm) 280 mmdrop(priv->mm); 281 282 return seq_release_private(inode, file); 283 } 284 285 static int pid_maps_open(struct inode *inode, struct file *file) 286 { 287 return maps_open(inode, file, &proc_pid_maps_ops); 288 } 289 290 const struct file_operations proc_pid_maps_operations = { 291 .open = pid_maps_open, 292 .read = seq_read, 293 .llseek = seq_lseek, 294 .release = map_release, 295 }; 296 297