// SPDX-License-Identifier: GPL-2.0 #include <linux/mm.h> #include <linux/file.h> #include <linux/fdtable.h> #include <linux/fs_struct.h> #include <linux/mount.h> #include <linux/ptrace.h> #include <linux/slab.h> #include <linux/seq_file.h> #include <linux/sched/mm.h> #include "internal.h" /* * Logic: we've got two memory sums for each process, "shared", and * "non-shared". Shared memory may get counted more than once, for * each process that owns it. Non-shared memory is counted * accurately. */ void task_mem(struct seq_file *m, struct mm_struct *mm) { struct vm_area_struct *vma; struct vm_region *region; struct rb_node *p; unsigned long bytes = 0, sbytes = 0, slack = 0, size; down_read(&mm->mmap_sem); for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) { vma = rb_entry(p, struct vm_area_struct, vm_rb); bytes += kobjsize(vma); region = vma->vm_region; if (region) { size = kobjsize(region); size += region->vm_end - region->vm_start; } else { size = vma->vm_end - vma->vm_start; } if (atomic_read(&mm->mm_count) > 1 || vma->vm_flags & VM_MAYSHARE) { sbytes += size; } else { bytes += size; if (region) slack = region->vm_end - vma->vm_end; } } if (atomic_read(&mm->mm_count) > 1) sbytes += kobjsize(mm); else bytes += kobjsize(mm); if (current->fs && current->fs->users > 1) sbytes += kobjsize(current->fs); else bytes += kobjsize(current->fs); if (current->files && atomic_read(¤t->files->count) > 1) sbytes += kobjsize(current->files); else bytes += kobjsize(current->files); if (current->sighand && atomic_read(¤t->sighand->count) > 1) sbytes += kobjsize(current->sighand); else bytes += kobjsize(current->sighand); bytes += kobjsize(current); /* includes kernel stack */ seq_printf(m, "Mem:\t%8lu bytes\n" "Slack:\t%8lu bytes\n" "Shared:\t%8lu bytes\n", bytes, slack, sbytes); up_read(&mm->mmap_sem); } unsigned long task_vsize(struct mm_struct *mm) { struct vm_area_struct *vma; struct rb_node *p; unsigned long vsize = 0; down_read(&mm->mmap_sem); for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) { vma = rb_entry(p, struct vm_area_struct, vm_rb); vsize += vma->vm_end - vma->vm_start; } up_read(&mm->mmap_sem); return vsize; } unsigned long task_statm(struct mm_struct *mm, unsigned long *shared, unsigned long *text, unsigned long *data, unsigned long *resident) { struct vm_area_struct *vma; struct vm_region *region; struct rb_node *p; unsigned long size = kobjsize(mm); down_read(&mm->mmap_sem); for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) { vma = rb_entry(p, struct vm_area_struct, vm_rb); size += kobjsize(vma); region = vma->vm_region; if (region) { size += kobjsize(region); size += region->vm_end - region->vm_start; } } *text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) >> PAGE_SHIFT; *data = (PAGE_ALIGN(mm->start_stack) - (mm->start_data & PAGE_MASK)) >> PAGE_SHIFT; up_read(&mm->mmap_sem); size >>= PAGE_SHIFT; size += *text + *data; *resident = size; return size; } static int is_stack(struct vm_area_struct *vma) { struct mm_struct *mm = vma->vm_mm; /* * We make no effort to guess what a given thread considers to be * its "stack". It's not even well-defined for programs written * languages like Go. */ return vma->vm_start <= mm->start_stack && vma->vm_end >= mm->start_stack; } /* * display a single VMA to a sequenced file */ static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma) { struct mm_struct *mm = vma->vm_mm; unsigned long ino = 0; struct file *file; dev_t dev = 0; int flags; unsigned long long pgoff = 0; flags = vma->vm_flags; file = vma->vm_file; if (file) { struct inode *inode = file_inode(vma->vm_file); dev = inode->i_sb->s_dev; ino = inode->i_ino; pgoff = (loff_t)vma->vm_pgoff << PAGE_SHIFT; } seq_setwidth(m, 25 + sizeof(void *) * 6 - 1); seq_printf(m, "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ", vma->vm_start, vma->vm_end, flags & VM_READ ? 'r' : '-', flags & VM_WRITE ? 'w' : '-', flags & VM_EXEC ? 'x' : '-', flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p', pgoff, MAJOR(dev), MINOR(dev), ino); if (file) { seq_pad(m, ' '); seq_file_path(m, file, ""); } else if (mm && is_stack(vma)) { seq_pad(m, ' '); seq_printf(m, "[stack]"); } seq_putc(m, '\n'); return 0; } /* * display mapping lines for a particular process's /proc/pid/maps */ static int show_map(struct seq_file *m, void *_p) { struct rb_node *p = _p; return nommu_vma_show(m, rb_entry(p, struct vm_area_struct, vm_rb)); } static void *m_start(struct seq_file *m, loff_t *pos) { struct proc_maps_private *priv = m->private; struct mm_struct *mm; struct rb_node *p; loff_t n = *pos; /* pin the task and mm whilst we play with them */ priv->task = get_proc_task(priv->inode); if (!priv->task) return ERR_PTR(-ESRCH); mm = priv->mm; if (!mm || !mmget_not_zero(mm)) return NULL; if (down_read_killable(&mm->mmap_sem)) { mmput(mm); return ERR_PTR(-EINTR); } /* start from the Nth VMA */ for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) if (n-- == 0) return p; up_read(&mm->mmap_sem); mmput(mm); return NULL; } static void m_stop(struct seq_file *m, void *_vml) { struct proc_maps_private *priv = m->private; if (!IS_ERR_OR_NULL(_vml)) { up_read(&priv->mm->mmap_sem); mmput(priv->mm); } if (priv->task) { put_task_struct(priv->task); priv->task = NULL; } } static void *m_next(struct seq_file *m, void *_p, loff_t *pos) { struct rb_node *p = _p; (*pos)++; return p ? rb_next(p) : NULL; } static const struct seq_operations proc_pid_maps_ops = { .start = m_start, .next = m_next, .stop = m_stop, .show = show_map }; static int maps_open(struct inode *inode, struct file *file, const struct seq_operations *ops) { struct proc_maps_private *priv; priv = __seq_open_private(file, ops, sizeof(*priv)); if (!priv) return -ENOMEM; priv->inode = inode; priv->mm = proc_mem_open(inode, PTRACE_MODE_READ); if (IS_ERR(priv->mm)) { int err = PTR_ERR(priv->mm); seq_release_private(inode, file); return err; } return 0; } static int map_release(struct inode *inode, struct file *file) { struct seq_file *seq = file->private_data; struct proc_maps_private *priv = seq->private; if (priv->mm) mmdrop(priv->mm); return seq_release_private(inode, file); } static int pid_maps_open(struct inode *inode, struct file *file) { return maps_open(inode, file, &proc_pid_maps_ops); } const struct file_operations proc_pid_maps_operations = { .open = pid_maps_open, .read = seq_read, .llseek = seq_lseek, .release = map_release, };