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 struct vm_area_struct *vma; 24 struct vm_region *region; 25 struct rb_node *p; 26 unsigned long bytes = 0, sbytes = 0, slack = 0, size; 27 28 down_read(&mm->mmap_sem); 29 for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) { 30 vma = rb_entry(p, struct vm_area_struct, vm_rb); 31 32 bytes += kobjsize(vma); 33 34 region = vma->vm_region; 35 if (region) { 36 size = kobjsize(region); 37 size += region->vm_end - region->vm_start; 38 } else { 39 size = vma->vm_end - vma->vm_start; 40 } 41 42 if (atomic_read(&mm->mm_count) > 1 || 43 vma->vm_flags & VM_MAYSHARE) { 44 sbytes += size; 45 } else { 46 bytes += size; 47 if (region) 48 slack = region->vm_end - vma->vm_end; 49 } 50 } 51 52 if (atomic_read(&mm->mm_count) > 1) 53 sbytes += kobjsize(mm); 54 else 55 bytes += kobjsize(mm); 56 57 if (current->fs && current->fs->users > 1) 58 sbytes += kobjsize(current->fs); 59 else 60 bytes += kobjsize(current->fs); 61 62 if (current->files && atomic_read(¤t->files->count) > 1) 63 sbytes += kobjsize(current->files); 64 else 65 bytes += kobjsize(current->files); 66 67 if (current->sighand && refcount_read(¤t->sighand->count) > 1) 68 sbytes += kobjsize(current->sighand); 69 else 70 bytes += kobjsize(current->sighand); 71 72 bytes += kobjsize(current); /* includes kernel stack */ 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 up_read(&mm->mmap_sem); 81 } 82 83 unsigned long task_vsize(struct mm_struct *mm) 84 { 85 struct vm_area_struct *vma; 86 struct rb_node *p; 87 unsigned long vsize = 0; 88 89 down_read(&mm->mmap_sem); 90 for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) { 91 vma = rb_entry(p, struct vm_area_struct, vm_rb); 92 vsize += vma->vm_end - vma->vm_start; 93 } 94 up_read(&mm->mmap_sem); 95 return vsize; 96 } 97 98 unsigned long task_statm(struct mm_struct *mm, 99 unsigned long *shared, unsigned long *text, 100 unsigned long *data, unsigned long *resident) 101 { 102 struct vm_area_struct *vma; 103 struct vm_region *region; 104 struct rb_node *p; 105 unsigned long size = kobjsize(mm); 106 107 down_read(&mm->mmap_sem); 108 for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) { 109 vma = rb_entry(p, struct vm_area_struct, vm_rb); 110 size += kobjsize(vma); 111 region = vma->vm_region; 112 if (region) { 113 size += kobjsize(region); 114 size += region->vm_end - region->vm_start; 115 } 116 } 117 118 *text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) 119 >> PAGE_SHIFT; 120 *data = (PAGE_ALIGN(mm->start_stack) - (mm->start_data & PAGE_MASK)) 121 >> PAGE_SHIFT; 122 up_read(&mm->mmap_sem); 123 size >>= PAGE_SHIFT; 124 size += *text + *data; 125 *resident = size; 126 return size; 127 } 128 129 static int is_stack(struct vm_area_struct *vma) 130 { 131 struct mm_struct *mm = vma->vm_mm; 132 133 /* 134 * We make no effort to guess what a given thread considers to be 135 * its "stack". It's not even well-defined for programs written 136 * languages like Go. 137 */ 138 return vma->vm_start <= mm->start_stack && 139 vma->vm_end >= mm->start_stack; 140 } 141 142 /* 143 * display a single VMA to a sequenced file 144 */ 145 static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma) 146 { 147 struct mm_struct *mm = vma->vm_mm; 148 unsigned long ino = 0; 149 struct file *file; 150 dev_t dev = 0; 151 int flags; 152 unsigned long long pgoff = 0; 153 154 flags = vma->vm_flags; 155 file = vma->vm_file; 156 157 if (file) { 158 struct inode *inode = file_inode(vma->vm_file); 159 dev = inode->i_sb->s_dev; 160 ino = inode->i_ino; 161 pgoff = (loff_t)vma->vm_pgoff << PAGE_SHIFT; 162 } 163 164 seq_setwidth(m, 25 + sizeof(void *) * 6 - 1); 165 seq_printf(m, 166 "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ", 167 vma->vm_start, 168 vma->vm_end, 169 flags & VM_READ ? 'r' : '-', 170 flags & VM_WRITE ? 'w' : '-', 171 flags & VM_EXEC ? 'x' : '-', 172 flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p', 173 pgoff, 174 MAJOR(dev), MINOR(dev), ino); 175 176 if (file) { 177 seq_pad(m, ' '); 178 seq_file_path(m, file, ""); 179 } else if (mm && is_stack(vma)) { 180 seq_pad(m, ' '); 181 seq_puts(m, "[stack]"); 182 } 183 184 seq_putc(m, '\n'); 185 return 0; 186 } 187 188 /* 189 * display mapping lines for a particular process's /proc/pid/maps 190 */ 191 static int show_map(struct seq_file *m, void *_p) 192 { 193 struct rb_node *p = _p; 194 195 return nommu_vma_show(m, rb_entry(p, struct vm_area_struct, vm_rb)); 196 } 197 198 static void *m_start(struct seq_file *m, loff_t *pos) 199 { 200 struct proc_maps_private *priv = m->private; 201 struct mm_struct *mm; 202 struct rb_node *p; 203 loff_t n = *pos; 204 205 /* pin the task and mm whilst we play with them */ 206 priv->task = get_proc_task(priv->inode); 207 if (!priv->task) 208 return ERR_PTR(-ESRCH); 209 210 mm = priv->mm; 211 if (!mm || !mmget_not_zero(mm)) 212 return NULL; 213 214 if (down_read_killable(&mm->mmap_sem)) { 215 mmput(mm); 216 return ERR_PTR(-EINTR); 217 } 218 219 /* start from the Nth VMA */ 220 for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) 221 if (n-- == 0) 222 return p; 223 224 up_read(&mm->mmap_sem); 225 mmput(mm); 226 return NULL; 227 } 228 229 static void m_stop(struct seq_file *m, void *_vml) 230 { 231 struct proc_maps_private *priv = m->private; 232 233 if (!IS_ERR_OR_NULL(_vml)) { 234 up_read(&priv->mm->mmap_sem); 235 mmput(priv->mm); 236 } 237 if (priv->task) { 238 put_task_struct(priv->task); 239 priv->task = NULL; 240 } 241 } 242 243 static void *m_next(struct seq_file *m, void *_p, loff_t *pos) 244 { 245 struct rb_node *p = _p; 246 247 (*pos)++; 248 return p ? rb_next(p) : NULL; 249 } 250 251 static const struct seq_operations proc_pid_maps_ops = { 252 .start = m_start, 253 .next = m_next, 254 .stop = m_stop, 255 .show = show_map 256 }; 257 258 static int maps_open(struct inode *inode, struct file *file, 259 const struct seq_operations *ops) 260 { 261 struct proc_maps_private *priv; 262 263 priv = __seq_open_private(file, ops, sizeof(*priv)); 264 if (!priv) 265 return -ENOMEM; 266 267 priv->inode = inode; 268 priv->mm = proc_mem_open(inode, PTRACE_MODE_READ); 269 if (IS_ERR(priv->mm)) { 270 int err = PTR_ERR(priv->mm); 271 272 seq_release_private(inode, file); 273 return err; 274 } 275 276 return 0; 277 } 278 279 280 static int map_release(struct inode *inode, struct file *file) 281 { 282 struct seq_file *seq = file->private_data; 283 struct proc_maps_private *priv = seq->private; 284 285 if (priv->mm) 286 mmdrop(priv->mm); 287 288 return seq_release_private(inode, file); 289 } 290 291 static int pid_maps_open(struct inode *inode, struct file *file) 292 { 293 return maps_open(inode, file, &proc_pid_maps_ops); 294 } 295 296 const struct file_operations proc_pid_maps_operations = { 297 .open = pid_maps_open, 298 .read = seq_read, 299 .llseek = seq_lseek, 300 .release = map_release, 301 }; 302 303