diff options
Diffstat (limited to 'fs/proc/task_nommu.c')
| -rw-r--r-- | fs/proc/task_nommu.c | 309 |
1 files changed, 309 insertions, 0 deletions
diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c new file mode 100644 index 000000000..dc05780f9 --- /dev/null +++ b/fs/proc/task_nommu.c @@ -0,0 +1,309 @@ +// 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) +{ + VMA_ITERATOR(vmi, mm, 0); + struct vm_area_struct *vma; + struct vm_region *region; + unsigned long bytes = 0, sbytes = 0, slack = 0, size; + + mmap_read_lock(mm); + for_each_vma(vmi, vma) { + 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 && refcount_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); + + mmap_read_unlock(mm); +} + +unsigned long task_vsize(struct mm_struct *mm) +{ + VMA_ITERATOR(vmi, mm, 0); + struct vm_area_struct *vma; + unsigned long vsize = 0; + + mmap_read_lock(mm); + for_each_vma(vmi, vma) + vsize += vma->vm_end - vma->vm_start; + mmap_read_unlock(mm); + return vsize; +} + +unsigned long task_statm(struct mm_struct *mm, + unsigned long *shared, unsigned long *text, + unsigned long *data, unsigned long *resident) +{ + VMA_ITERATOR(vmi, mm, 0); + struct vm_area_struct *vma; + struct vm_region *region; + unsigned long size = kobjsize(mm); + + mmap_read_lock(mm); + for_each_vma(vmi, vma) { + 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; + mmap_read_unlock(mm); + 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_puts(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) +{ + return nommu_vma_show(m, _p); +} + +static struct vm_area_struct *proc_get_vma(struct proc_maps_private *priv, + loff_t *ppos) +{ + struct vm_area_struct *vma = vma_next(&priv->iter); + + if (vma) { + *ppos = vma->vm_start; + } else { + *ppos = -1UL; + } + + return vma; +} + +static void *m_start(struct seq_file *m, loff_t *ppos) +{ + struct proc_maps_private *priv = m->private; + unsigned long last_addr = *ppos; + struct mm_struct *mm; + + /* See proc_get_vma(). Zero at the start or after lseek. */ + if (last_addr == -1UL) + return NULL; + + /* 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)) { + put_task_struct(priv->task); + priv->task = NULL; + return NULL; + } + + if (mmap_read_lock_killable(mm)) { + mmput(mm); + put_task_struct(priv->task); + priv->task = NULL; + return ERR_PTR(-EINTR); + } + + vma_iter_init(&priv->iter, mm, last_addr); + + return proc_get_vma(priv, ppos); +} + +static void m_stop(struct seq_file *m, void *v) +{ + struct proc_maps_private *priv = m->private; + struct mm_struct *mm = priv->mm; + + if (!priv->task) + return; + + mmap_read_unlock(mm); + mmput(mm); + put_task_struct(priv->task); + priv->task = NULL; +} + +static void *m_next(struct seq_file *m, void *_p, loff_t *ppos) +{ + return proc_get_vma(m->private, ppos); +} + +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, +}; + |