Commit message: pagemap: do not leak physical addresses to non-privileged userspace

As pointed by recent post[1] on exploiting DRAM physical imperfection,
/proc/PID/pagemap exposes sensitive information which can be used to do
attacks.

This disallows anybody without CAP_SYS_ADMIN to read the pagemap.

[1] http://googleprojectzero.blogspot.com/2015/03/exploiting-dram-rowhammer-bug-to-gain.html

[ Eventually we might want to do anything more finegrained, but for now
  this is the simple model.   - Linus ]

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mark Seaborn <mseaborn@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
CVE: CVE-2016-0823
CWE: CWE-200
Vulnerability description: The pagemap_open function in fs/proc/task_mmu.c in the Linux kernel before 3.19.3, as used in Android 6.0.1 before 2016-03-01, allows local users to obtain sensitive physical-address information by reading a pagemap file, aka Android internal bug 25739721.

Project: linux
File: task_mmu.c

static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme,
			  struct pagemapread *pm)
{
	pm->buffer[pm->pos++] = *pme;
	if (pm->pos >= pm->len)
		return PM_END_OF_BUFFER;
	return 0;
}

Project: linux
File: task_mmu.c

static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
		unsigned long addr)
{
	struct page *page;
	int nid;

	if (!pte_present(pte))
		return NULL;

	page = vm_normal_page(vma, addr, pte);
	if (!page)
		return NULL;

	if (PageReserved(page))
		return NULL;

	nid = page_to_nid(page);
	if (!node_isset(nid, node_states[N_MEMORY]))
		return NULL;

	return page;
}

Project: linux
File: task_mmu.c

static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
				unsigned long end, struct mm_walk *walk)
{
	struct clear_refs_private *cp = walk->private;
	struct vm_area_struct *vma = walk->vma;
	pte_t *pte, ptent;
	spinlock_t *ptl;
	struct page *page;

	if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
			clear_soft_dirty_pmd(vma, addr, pmd);
			goto out;
		}

		page = pmd_page(*pmd);

		/* Clear accessed and referenced bits. */
		pmdp_test_and_clear_young(vma, addr, pmd);
		ClearPageReferenced(page);
out:
		spin_unlock(ptl);
		return 0;
	}

	if (pmd_trans_unstable(pmd))
		return 0;

	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
	for (; addr != end; pte++, addr += PAGE_SIZE) {
		ptent = *pte;

		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
			clear_soft_dirty(vma, addr, pte);
			continue;
		}

		if (!pte_present(ptent))
			continue;

		page = vm_normal_page(vma, addr, ptent);
		if (!page)
			continue;

		/* Clear accessed and referenced bits. */
		ptep_test_and_clear_young(vma, addr, pte);
		ClearPageReferenced(page);
	}
	pte_unmap_unlock(pte - 1, ptl);
	cond_resched();
	return 0;
}

Project: linux
File: task_mmu.c

static ssize_t clear_refs_write(struct file *file, const char __user *buf,
				size_t count, loff_t *ppos)
{
	struct task_struct *task;
	char buffer[PROC_NUMBUF];
	struct mm_struct *mm;
	struct vm_area_struct *vma;
	enum clear_refs_types type;
	int itype;
	int rv;

	memset(buffer, 0, sizeof(buffer));
	if (count > sizeof(buffer) - 1)
		count = sizeof(buffer) - 1;
	if (copy_from_user(buffer, buf, count))
		return -EFAULT;
	rv = kstrtoint(strstrip(buffer), 10, &itype);
	if (rv < 0)
		return rv;
	type = (enum clear_refs_types)itype;
	if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
		return -EINVAL;

	if (type == CLEAR_REFS_SOFT_DIRTY) {
		soft_dirty_cleared = true;
		pr_warn_once("The pagemap bits 55-60 has changed their meaning!"
			     " See the linux/Documentation/vm/pagemap.txt for "
			     "details.\n");
	}

	task = get_proc_task(file_inode(file));
	if (!task)
		return -ESRCH;
	mm = get_task_mm(task);
	if (mm) {
		struct clear_refs_private cp = {
			.type = type,
		};
		struct mm_walk clear_refs_walk = {
			.pmd_entry = clear_refs_pte_range,
			.test_walk = clear_refs_test_walk,
			.mm = mm,
			.private = &cp,
		};

		if (type == CLEAR_REFS_MM_HIWATER_RSS) {
			/*
			 * Writing 5 to /proc/pid/clear_refs resets the peak
			 * resident set size to this mm's current rss value.
			 */
			down_write(&mm->mmap_sem);
			reset_mm_hiwater_rss(mm);
			up_write(&mm->mmap_sem);
			goto out_mm;
		}

		down_read(&mm->mmap_sem);
		if (type == CLEAR_REFS_SOFT_DIRTY) {
			for (vma = mm->mmap; vma; vma = vma->vm_next) {
				if (!(vma->vm_flags & VM_SOFTDIRTY))
					continue;
				up_read(&mm->mmap_sem);
				down_write(&mm->mmap_sem);
				for (vma = mm->mmap; vma; vma = vma->vm_next) {
					vma->vm_flags &= ~VM_SOFTDIRTY;
					vma_set_page_prot(vma);
				}
				downgrade_write(&mm->mmap_sem);
				break;
			}
			mmu_notifier_invalidate_range_start(mm, 0, -1);
		}
		walk_page_range(0, ~0UL, &clear_refs_walk);
		if (type == CLEAR_REFS_SOFT_DIRTY)
			mmu_notifier_invalidate_range_end(mm, 0, -1);
		flush_tlb_mm(mm);
		up_read(&mm->mmap_sem);
out_mm:
		mmput(mm);
	}
	put_task_struct(task);

	return count;
}

Project: linux
File: task_mmu.c

static inline void clear_soft_dirty(struct vm_area_struct *vma,
		unsigned long addr, pte_t *pte)
{
	/*
	 * The soft-dirty tracker uses #PF-s to catch writes
	 * to pages, so write-protect the pte as well. See the
	 * Documentation/vm/soft-dirty.txt for full description
	 * of how soft-dirty works.
	 */
	pte_t ptent = *pte;

	if (pte_present(ptent)) {
		ptent = pte_wrprotect(ptent);
		ptent = pte_clear_flags(ptent, _PAGE_SOFT_DIRTY);
	} else if (is_swap_pte(ptent)) {
		ptent = pte_swp_clear_soft_dirty(ptent);
	}

	set_pte_at(vma->vm_mm, addr, pte, ptent);
}

Project: linux
File: task_mmu.c

static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
		unsigned long addr, pmd_t *pmdp)
{
	pmd_t pmd = *pmdp;

	pmd = pmd_wrprotect(pmd);
	pmd = pmd_clear_flags(pmd, _PAGE_SOFT_DIRTY);

	if (vma->vm_flags & VM_SOFTDIRTY)
		vma->vm_flags &= ~VM_SOFTDIRTY;

	set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
}

Project: linux
File: task_mmu.c

static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
		unsigned long addr, pmd_t *pmdp)
{
}

Project: linux
File: task_mmu.c

static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
		unsigned long addr, unsigned long end, struct mm_walk *walk)
{
	struct numa_maps *md;
	struct page *page;

	if (!pte_present(*pte))
		return 0;

	page = pte_page(*pte);
	if (!page)
		return 0;

	md = walk->private;
	gather_stats(page, md, pte_dirty(*pte), 1);
	return 0;
}

Project: linux
File: task_mmu.c

static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
		unsigned long addr, unsigned long end, struct mm_walk *walk)
{
	return 0;
}

Project: linux
File: task_mmu.c

static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
		unsigned long end, struct mm_walk *walk)
{
	struct numa_maps *md = walk->private;
	struct vm_area_struct *vma = walk->vma;
	spinlock_t *ptl;
	pte_t *orig_pte;
	pte_t *pte;

	if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
		pte_t huge_pte = *(pte_t *)pmd;
		struct page *page;

		page = can_gather_numa_stats(huge_pte, vma, addr);
		if (page)
			gather_stats(page, md, pte_dirty(huge_pte),
				     HPAGE_PMD_SIZE/PAGE_SIZE);
		spin_unlock(ptl);
		return 0;
	}

	if (pmd_trans_unstable(pmd))
		return 0;
	orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
	do {
		struct page *page = can_gather_numa_stats(*pte, vma, addr);
		if (!page)
			continue;
		gather_stats(page, md, pte_dirty(*pte), 1);

	} while (pte++, addr += PAGE_SIZE, addr != end);
	pte_unmap_unlock(orig_pte, ptl);
	return 0;
}

Project: linux
File: task_mmu.c

static void hold_task_mempolicy(struct proc_maps_private *priv)
{
	struct task_struct *task = priv->task;

	task_lock(task);
	priv->task_mempolicy = get_task_policy(task);
	mpol_get(priv->task_mempolicy);
	task_unlock(task);
}

Project: linux
File: task_mmu.c

static void hold_task_mempolicy(struct proc_maps_private *priv)
{
}

Project: linux
File: task_mmu.c

static void huge_pte_to_pagemap_entry(pagemap_entry_t *pme, struct pagemapread *pm,
					pte_t pte, int offset, int flags2)
{
	if (pte_present(pte))
		*pme = make_pme(PM_PFRAME(pte_pfn(pte) + offset)	|
				PM_STATUS2(pm->v2, flags2)		|
				PM_PRESENT);
	else
		*pme = make_pme(PM_NOT_PRESENT(pm->v2)			|
				PM_STATUS2(pm->v2, flags2));
}

Project: linux
File: task_mmu.c

static void m_cache_vma(struct seq_file *m, struct vm_area_struct *vma)
{
	if (m->count < m->size)	/* vma is copied successfully */
		m->version = m_next_vma(m->private, vma) ? vma->vm_start : -1UL;
}

Project: linux
File: task_mmu.c

static void *m_next(struct seq_file *m, void *v, loff_t *pos)
{
	struct proc_maps_private *priv = m->private;
	struct vm_area_struct *next;

	(*pos)++;
	next = m_next_vma(priv, v);
	if (!next)
		vma_stop(priv);
	return next;
}

Project: linux
File: task_mmu.c

m_next_vma(struct proc_maps_private *priv, struct vm_area_struct *vma)
{
	if (vma == priv->tail_vma)
		return NULL;
	return vma->vm_next ?: priv->tail_vma;
}

Project: linux
File: task_mmu.c

static void *m_start(struct seq_file *m, loff_t *ppos)
{
	struct proc_maps_private *priv = m->private;
	unsigned long last_addr = m->version;
	struct mm_struct *mm;
	struct vm_area_struct *vma;
	unsigned int pos = *ppos;

	/* See m_cache_vma(). Zero at the start or after lseek. */
	if (last_addr == -1UL)
		return NULL;

	priv->task = get_proc_task(priv->inode);
	if (!priv->task)
		return ERR_PTR(-ESRCH);

	mm = priv->mm;
	if (!mm || !atomic_inc_not_zero(&mm->mm_users))
		return NULL;

	down_read(&mm->mmap_sem);
	hold_task_mempolicy(priv);
	priv->tail_vma = get_gate_vma(mm);

	if (last_addr) {
		vma = find_vma(mm, last_addr);
		if (vma && (vma = m_next_vma(priv, vma)))
			return vma;
	}

	m->version = 0;
	if (pos < mm->map_count) {
		for (vma = mm->mmap; pos; pos--) {
			m->version = vma->vm_start;
			vma = vma->vm_next;
		}
		return vma;
	}

	/* we do not bother to update m->version in this case */
	if (pos == mm->map_count && priv->tail_vma)
		return priv->tail_vma;

	vma_stop(priv);
	return NULL;
}

Project: linux
File: task_mmu.c

static void m_stop(struct seq_file *m, void *v)
{
	struct proc_maps_private *priv = m->private;

	if (!IS_ERR_OR_NULL(v))
		vma_stop(priv);
	if (priv->task) {
		put_task_struct(priv->task);
		priv->task = NULL;
	}
}

Project: linux
File: task_mmu.c

static int numa_maps_open(struct inode *inode, struct file *file,
			  const struct seq_operations *ops)
{
	return proc_maps_open(inode, file, ops,
				sizeof(struct numa_maps_private));
}

Project: linux
File: task_mmu.c

static int pagemap_hugetlb_range(pte_t *pte, unsigned long hmask,
				 unsigned long addr, unsigned long end,
				 struct mm_walk *walk)
{
	struct pagemapread *pm = walk->private;
	struct vm_area_struct *vma = walk->vma;
	int err = 0;
	int flags2;
	pagemap_entry_t pme;

	if (vma->vm_flags & VM_SOFTDIRTY)
		flags2 = __PM_SOFT_DIRTY;
	else
		flags2 = 0;

	for (; addr != end; addr += PAGE_SIZE) {
		int offset = (addr & ~hmask) >> PAGE_SHIFT;
		huge_pte_to_pagemap_entry(&pme, pm, *pte, offset, flags2);
		err = add_to_pagemap(addr, &pme, pm);
		if (err)
			return err;
	}

	cond_resched();

	return err;
}

Project: linux
File: task_mmu.c

static int pagemap_pte_hole(unsigned long start, unsigned long end,
				struct mm_walk *walk)
{
	struct pagemapread *pm = walk->private;
	unsigned long addr = start;
	int err = 0;

	while (addr < end) {
		struct vm_area_struct *vma = find_vma(walk->mm, addr);
		pagemap_entry_t pme = make_pme(PM_NOT_PRESENT(pm->v2));
		/* End of address space hole, which we mark as non-present. */
		unsigned long hole_end;

		if (vma)
			hole_end = min(end, vma->vm_start);
		else
			hole_end = end;

		for (; addr < hole_end; addr += PAGE_SIZE) {
			err = add_to_pagemap(addr, &pme, pm);
			if (err)
				goto out;
		}

		if (!vma)
			break;

		/* Addresses in the VMA. */
		if (vma->vm_flags & VM_SOFTDIRTY)
			pme.pme |= PM_STATUS2(pm->v2, __PM_SOFT_DIRTY);
		for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) {
			err = add_to_pagemap(addr, &pme, pm);
			if (err)
				goto out;
		}
	}
out:
	return err;
}

Project: linux
File: task_mmu.c

static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
			     struct mm_walk *walk)
{
	struct vm_area_struct *vma = walk->vma;
	struct pagemapread *pm = walk->private;
	spinlock_t *ptl;
	pte_t *pte, *orig_pte;
	int err = 0;

	if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
		int pmd_flags2;

		if ((vma->vm_flags & VM_SOFTDIRTY) || pmd_soft_dirty(*pmd))
			pmd_flags2 = __PM_SOFT_DIRTY;
		else
			pmd_flags2 = 0;

		for (; addr != end; addr += PAGE_SIZE) {
			unsigned long offset;
			pagemap_entry_t pme;

			offset = (addr & ~PAGEMAP_WALK_MASK) >>
					PAGE_SHIFT;
			thp_pmd_to_pagemap_entry(&pme, pm, *pmd, offset, pmd_flags2);
			err = add_to_pagemap(addr, &pme, pm);
			if (err)
				break;
		}
		spin_unlock(ptl);
		return err;
	}

	if (pmd_trans_unstable(pmd))
		return 0;

	/*
	 * We can assume that @vma always points to a valid one and @end never
	 * goes beyond vma->vm_end.
	 */
	orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
	for (; addr < end; pte++, addr += PAGE_SIZE) {
		pagemap_entry_t pme;

		pte_to_pagemap_entry(&pme, pm, vma, addr, *pte);
		err = add_to_pagemap(addr, &pme, pm);
		if (err)
			break;
	}
	pte_unmap_unlock(orig_pte, ptl);

	cond_resched();

	return err;
}

Project: linux
File: task_mmu.c

static ssize_t pagemap_read(struct file *file, char __user *buf,
			    size_t count, loff_t *ppos)
{
	struct task_struct *task = get_proc_task(file_inode(file));
	struct mm_struct *mm;
	struct pagemapread pm;
	int ret = -ESRCH;
	struct mm_walk pagemap_walk = {};
	unsigned long src;
	unsigned long svpfn;
	unsigned long start_vaddr;
	unsigned long end_vaddr;
	int copied = 0;

	if (!task)
		goto out;

	ret = -EINVAL;
	/* file position must be aligned */
	if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
		goto out_task;

	ret = 0;
	if (!count)
		goto out_task;

	pm.v2 = soft_dirty_cleared;
	pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
	pm.buffer = kmalloc(pm.len * PM_ENTRY_BYTES, GFP_TEMPORARY);
	ret = -ENOMEM;
	if (!pm.buffer)
		goto out_task;

	mm = mm_access(task, PTRACE_MODE_READ);
	ret = PTR_ERR(mm);
	if (!mm || IS_ERR(mm))
		goto out_free;

	pagemap_walk.pmd_entry = pagemap_pte_range;
	pagemap_walk.pte_hole = pagemap_pte_hole;
#ifdef CONFIG_HUGETLB_PAGE
	pagemap_walk.hugetlb_entry = pagemap_hugetlb_range;
#endif
	pagemap_walk.mm = mm;
	pagemap_walk.private = &pm;

	src = *ppos;
	svpfn = src / PM_ENTRY_BYTES;
	start_vaddr = svpfn << PAGE_SHIFT;
	end_vaddr = TASK_SIZE_OF(task);

	/* watch out for wraparound */
	if (svpfn > TASK_SIZE_OF(task) >> PAGE_SHIFT)
		start_vaddr = end_vaddr;

	/*
	 * The odds are that this will stop walking way
	 * before end_vaddr, because the length of the
	 * user buffer is tracked in "pm", and the walk
	 * will stop when we hit the end of the buffer.
	 */
	ret = 0;
	while (count && (start_vaddr < end_vaddr)) {
		int len;
		unsigned long end;

		pm.pos = 0;
		end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK;
		/* overflow ? */
		if (end < start_vaddr || end > end_vaddr)
			end = end_vaddr;
		down_read(&mm->mmap_sem);
		ret = walk_page_range(start_vaddr, end, &pagemap_walk);
		up_read(&mm->mmap_sem);
		start_vaddr = end;

		len = min(count, PM_ENTRY_BYTES * pm.pos);
		if (copy_to_user(buf, pm.buffer, len)) {
			ret = -EFAULT;
			goto out_mm;
		}
		copied += len;
		buf += len;
		count -= len;
	}
	*ppos += copied;
	if (!ret || ret == PM_END_OF_BUFFER)
		ret = copied;

out_mm:
	mmput(mm);
out_free:
	kfree(pm.buffer);
out_task:
	put_task_struct(task);
out:
	return ret;
}

Project: linux
File: task_mmu.c

static int pid_numa_maps_open(struct inode *inode, struct file *file)
{
	return numa_maps_open(inode, file, &proc_pid_numa_maps_op);
}

Project: linux
File: task_mmu.c

static int pid_smaps_open(struct inode *inode, struct file *file)
{
	return do_maps_open(inode, file, &proc_pid_smaps_op);
}

Project: linux
File: task_mmu.c

static int proc_maps_open(struct inode *inode, struct file *file,
			const struct seq_operations *ops, int psize)
{
	struct proc_maps_private *priv = __seq_open_private(file, ops, psize);

	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;
}

Project: linux
File: task_mmu.c

static void pte_to_pagemap_entry(pagemap_entry_t *pme, struct pagemapread *pm,
		struct vm_area_struct *vma, unsigned long addr, pte_t pte)
{
	u64 frame, flags;
	struct page *page = NULL;
	int flags2 = 0;

	if (pte_present(pte)) {
		frame = pte_pfn(pte);
		flags = PM_PRESENT;
		page = vm_normal_page(vma, addr, pte);
		if (pte_soft_dirty(pte))
			flags2 |= __PM_SOFT_DIRTY;
	} else if (is_swap_pte(pte)) {
		swp_entry_t entry;
		if (pte_swp_soft_dirty(pte))
			flags2 |= __PM_SOFT_DIRTY;
		entry = pte_to_swp_entry(pte);
		frame = swp_type(entry) |
			(swp_offset(entry) << MAX_SWAPFILES_SHIFT);
		flags = PM_SWAP;
		if (is_migration_entry(entry))
			page = migration_entry_to_page(entry);
	} else {
		if (vma->vm_flags & VM_SOFTDIRTY)
			flags2 |= __PM_SOFT_DIRTY;
		*pme = make_pme(PM_NOT_PRESENT(pm->v2) | PM_STATUS2(pm->v2, flags2));
		return;
	}

	if (page && !PageAnon(page))
		flags |= PM_FILE;
	if ((vma->vm_flags & VM_SOFTDIRTY))
		flags2 |= __PM_SOFT_DIRTY;

	*pme = make_pme(PM_PFRAME(frame) | PM_STATUS2(pm->v2, flags2) | flags);
}

Project: linux
File: task_mmu.c

static void release_task_mempolicy(struct proc_maps_private *priv)
{
	mpol_put(priv->task_mempolicy);
}

Project: linux
File: task_mmu.c

static int show_map(struct seq_file *m, void *v, int is_pid)
{
	show_map_vma(m, v, is_pid);
	m_cache_vma(m, v);
	return 0;
}

Project: linux
File: task_mmu.c

show_map_vma(struct seq_file *m, struct vm_area_struct *vma, int is_pid)
{
	struct mm_struct *mm = vma->vm_mm;
	struct file *file = vma->vm_file;
	struct proc_maps_private *priv = m->private;
	vm_flags_t flags = vma->vm_flags;
	unsigned long ino = 0;
	unsigned long long pgoff = 0;
	unsigned long start, end;
	dev_t dev = 0;
	const char *name = NULL;

	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;
	}

	/* We don't show the stack guard page in /proc/maps */
	start = vma->vm_start;
	if (stack_guard_page_start(vma, start))
		start += PAGE_SIZE;
	end = vma->vm_end;
	if (stack_guard_page_end(vma, end))
		end -= PAGE_SIZE;

	seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
	seq_printf(m, "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ",
			start,
			end,
			flags & VM_READ ? 'r' : '-',
			flags & VM_WRITE ? 'w' : '-',
			flags & VM_EXEC ? 'x' : '-',
			flags & VM_MAYSHARE ? 's' : 'p',
			pgoff,
			MAJOR(dev), MINOR(dev), ino);

	/*
	 * Print the dentry name for named mappings, and a
	 * special [heap] marker for the heap:
	 */
	if (file) {
		seq_pad(m, ' ');
		seq_path(m, &file->f_path, "\n");
		goto done;
	}

	if (vma->vm_ops && vma->vm_ops->name) {
		name = vma->vm_ops->name(vma);
		if (name)
			goto done;
	}

	name = arch_vma_name(vma);
	if (!name) {
		pid_t tid;

		if (!mm) {
			name = "[vdso]";
			goto done;
		}

		if (vma->vm_start <= mm->brk &&
		    vma->vm_end >= mm->start_brk) {
			name = "[heap]";
			goto done;
		}

		tid = pid_of_stack(priv, vma, is_pid);
		if (tid != 0) {
			/*
			 * Thread stack in /proc/PID/task/TID/maps or
			 * the main process stack.
			 */
			if (!is_pid || (vma->vm_start <= mm->start_stack &&
			    vma->vm_end >= mm->start_stack)) {
				name = "[stack]";
			} else {
				/* Thread stack in /proc/PID/maps */
				seq_pad(m, ' ');
				seq_printf(m, "[stack:%d]", tid);
			}
		}
	}

done:
	if (name) {
		seq_pad(m, ' ');
		seq_puts(m, name);
	}
	seq_putc(m, '\n');
}

Project: linux
File: task_mmu.c

static int show_numa_map(struct seq_file *m, void *v, int is_pid)
{
	struct numa_maps_private *numa_priv = m->private;
	struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
	struct vm_area_struct *vma = v;
	struct numa_maps *md = &numa_priv->md;
	struct file *file = vma->vm_file;
	struct mm_struct *mm = vma->vm_mm;
	struct mm_walk walk = {
		.hugetlb_entry = gather_hugetlb_stats,
		.pmd_entry = gather_pte_stats,
		.private = md,
		.mm = mm,
	};
	struct mempolicy *pol;
	char buffer[64];
	int nid;

	if (!mm)
		return 0;

	/* Ensure we start with an empty set of numa_maps statistics. */
	memset(md, 0, sizeof(*md));

	pol = __get_vma_policy(vma, vma->vm_start);
	if (pol) {
		mpol_to_str(buffer, sizeof(buffer), pol);
		mpol_cond_put(pol);
	} else {
		mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy);
	}

	seq_printf(m, "%08lx %s", vma->vm_start, buffer);

	if (file) {
		seq_puts(m, " file=");
		seq_path(m, &file->f_path, "\n\t= ");
	} else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
		seq_puts(m, " heap");
	} else {
		pid_t tid = pid_of_stack(proc_priv, vma, is_pid);
		if (tid != 0) {
			/*
			 * Thread stack in /proc/PID/task/TID/maps or
			 * the main process stack.
			 */
			if (!is_pid || (vma->vm_start <= mm->start_stack &&
			    vma->vm_end >= mm->start_stack))
				seq_puts(m, " stack");
			else
				seq_printf(m, " stack:%d", tid);
		}
	}

	if (is_vm_hugetlb_page(vma))
		seq_puts(m, " huge");

	/* mmap_sem is held by m_start */
	walk_page_vma(vma, &walk);

	if (!md->pages)
		goto out;

	if (md->anon)
		seq_printf(m, " anon=%lu", md->anon);

	if (md->dirty)
		seq_printf(m, " dirty=%lu", md->dirty);

	if (md->pages != md->anon && md->pages != md->dirty)
		seq_printf(m, " mapped=%lu", md->pages);

	if (md->mapcount_max > 1)
		seq_printf(m, " mapmax=%lu", md->mapcount_max);

	if (md->swapcache)
		seq_printf(m, " swapcache=%lu", md->swapcache);

	if (md->active < md->pages && !is_vm_hugetlb_page(vma))
		seq_printf(m, " active=%lu", md->active);

	if (md->writeback)
		seq_printf(m, " writeback=%lu", md->writeback);

	for_each_node_state(nid, N_MEMORY)
		if (md->node[nid])
			seq_printf(m, " N%d=%lu", nid, md->node[nid]);

	seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10);
out:
	seq_putc(m, '\n');
	m_cache_vma(m, vma);
	return 0;
}

Project: linux
File: task_mmu.c

static int show_pid_map(struct seq_file *m, void *v)
{
	return show_map(m, v, 1);
}

Project: linux
File: task_mmu.c

static int show_pid_numa_map(struct seq_file *m, void *v)
{
	return show_numa_map(m, v, 1);
}

Project: linux
File: task_mmu.c

static int show_pid_smap(struct seq_file *m, void *v)
{
	return show_smap(m, v, 1);
}

Project: linux
File: task_mmu.c

static int show_smap(struct seq_file *m, void *v, int is_pid)
{
	struct vm_area_struct *vma = v;
	struct mem_size_stats mss;
	struct mm_walk smaps_walk = {
		.pmd_entry = smaps_pte_range,
		.mm = vma->vm_mm,
		.private = &mss,
	};

	memset(&mss, 0, sizeof mss);
	/* mmap_sem is held in m_start */
	walk_page_vma(vma, &smaps_walk);

	show_map_vma(m, vma, is_pid);

	seq_printf(m,
		   "Size:           %8lu kB\n"
		   "Rss:            %8lu kB\n"
		   "Pss:            %8lu kB\n"
		   "Shared_Clean:   %8lu kB\n"
		   "Shared_Dirty:   %8lu kB\n"
		   "Private_Clean:  %8lu kB\n"
		   "Private_Dirty:  %8lu kB\n"
		   "Referenced:     %8lu kB\n"
		   "Anonymous:      %8lu kB\n"
		   "AnonHugePages:  %8lu kB\n"
		   "Swap:           %8lu kB\n"
		   "KernelPageSize: %8lu kB\n"
		   "MMUPageSize:    %8lu kB\n"
		   "Locked:         %8lu kB\n",
		   (vma->vm_end - vma->vm_start) >> 10,
		   mss.resident >> 10,
		   (unsigned long)(mss.pss >> (10 + PSS_SHIFT)),
		   mss.shared_clean  >> 10,
		   mss.shared_dirty  >> 10,
		   mss.private_clean >> 10,
		   mss.private_dirty >> 10,
		   mss.referenced >> 10,
		   mss.anonymous >> 10,
		   mss.anonymous_thp >> 10,
		   mss.swap >> 10,
		   vma_kernel_pagesize(vma) >> 10,
		   vma_mmu_pagesize(vma) >> 10,
		   (vma->vm_flags & VM_LOCKED) ?
			(unsigned long)(mss.pss >> (10 + PSS_SHIFT)) : 0);

	show_smap_vma_flags(m, vma);
	m_cache_vma(m, vma);
	return 0;
}

Project: linux
File: task_mmu.c

static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
{
	/*
	 * Don't forget to update Documentation/ on changes.
	 */
	static const char mnemonics[BITS_PER_LONG][2] = {
		/*
		 * In case if we meet a flag we don't know about.
		 */
		[0 ... (BITS_PER_LONG-1)] = "??",

		[ilog2(VM_READ)]	= "rd",
		[ilog2(VM_WRITE)]	= "wr",
		[ilog2(VM_EXEC)]	= "ex",
		[ilog2(VM_SHARED)]	= "sh",
		[ilog2(VM_MAYREAD)]	= "mr",
		[ilog2(VM_MAYWRITE)]	= "mw",
		[ilog2(VM_MAYEXEC)]	= "me",
		[ilog2(VM_MAYSHARE)]	= "ms",
		[ilog2(VM_GROWSDOWN)]	= "gd",
		[ilog2(VM_PFNMAP)]	= "pf",
		[ilog2(VM_DENYWRITE)]	= "dw",
#ifdef CONFIG_X86_INTEL_MPX
		[ilog2(VM_MPX)]		= "mp",
#endif
		[ilog2(VM_LOCKED)]	= "lo",
		[ilog2(VM_IO)]		= "io",
		[ilog2(VM_SEQ_READ)]	= "sr",
		[ilog2(VM_RAND_READ)]	= "rr",
		[ilog2(VM_DONTCOPY)]	= "dc",
		[ilog2(VM_DONTEXPAND)]	= "de",
		[ilog2(VM_ACCOUNT)]	= "ac",
		[ilog2(VM_NORESERVE)]	= "nr",
		[ilog2(VM_HUGETLB)]	= "ht",
		[ilog2(VM_ARCH_1)]	= "ar",
		[ilog2(VM_DONTDUMP)]	= "dd",
#ifdef CONFIG_MEM_SOFT_DIRTY
		[ilog2(VM_SOFTDIRTY)]	= "sd",
#endif
		[ilog2(VM_MIXEDMAP)]	= "mm",
		[ilog2(VM_HUGEPAGE)]	= "hg",
		[ilog2(VM_NOHUGEPAGE)]	= "nh",
		[ilog2(VM_MERGEABLE)]	= "mg",
	};
	size_t i;

	seq_puts(m, "VmFlags: ");
	for (i = 0; i < BITS_PER_LONG; i++) {
		if (vma->vm_flags & (1UL << i)) {
			seq_printf(m, "%c%c ",
				   mnemonics[i][0], mnemonics[i][1]);
		}
	}
	seq_putc(m, '\n');
}

Project: linux
File: task_mmu.c

static int show_tid_map(struct seq_file *m, void *v)
{
	return show_map(m, v, 0);
}

Project: linux
File: task_mmu.c

static int show_tid_smap(struct seq_file *m, void *v)
{
	return show_smap(m, v, 0);
}

Project: linux
File: task_mmu.c

static void smaps_account(struct mem_size_stats *mss, struct page *page,
		unsigned long size, bool young, bool dirty)
{
	int mapcount;

	if (PageAnon(page))
		mss->anonymous += size;

	mss->resident += size;
	/* Accumulate the size in pages that have been accessed. */
	if (young || PageReferenced(page))
		mss->referenced += size;
	mapcount = page_mapcount(page);
	if (mapcount >= 2) {
		u64 pss_delta;

		if (dirty || PageDirty(page))
			mss->shared_dirty += size;
		else
			mss->shared_clean += size;
		pss_delta = (u64)size << PSS_SHIFT;
		do_div(pss_delta, mapcount);
		mss->pss += pss_delta;
	} else {
		if (dirty || PageDirty(page))
			mss->private_dirty += size;
		else
			mss->private_clean += size;
		mss->pss += (u64)size << PSS_SHIFT;
	}
}

Project: linux
File: task_mmu.c

static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
		struct mm_walk *walk)
{
	struct mem_size_stats *mss = walk->private;
	struct vm_area_struct *vma = walk->vma;
	struct page *page;

	/* FOLL_DUMP will return -EFAULT on huge zero page */
	page = follow_trans_huge_pmd(vma, addr, pmd, FOLL_DUMP);
	if (IS_ERR_OR_NULL(page))
		return;
	mss->anonymous_thp += HPAGE_PMD_SIZE;
	smaps_account(mss, page, HPAGE_PMD_SIZE,
			pmd_young(*pmd), pmd_dirty(*pmd));
}

Project: linux
File: task_mmu.c

static void smaps_pte_entry(pte_t *pte, unsigned long addr,
		struct mm_walk *walk)
{
	struct mem_size_stats *mss = walk->private;
	struct vm_area_struct *vma = walk->vma;
	struct page *page = NULL;

	if (pte_present(*pte)) {
		page = vm_normal_page(vma, addr, *pte);
	} else if (is_swap_pte(*pte)) {
		swp_entry_t swpent = pte_to_swp_entry(*pte);

		if (!non_swap_entry(swpent))
			mss->swap += PAGE_SIZE;
		else if (is_migration_entry(swpent))
			page = migration_entry_to_page(swpent);
	}

	if (!page)
		return;
	smaps_account(mss, page, PAGE_SIZE, pte_young(*pte), pte_dirty(*pte));
}

Project: linux
File: task_mmu.c

void task_mem(struct seq_file *m, struct mm_struct *mm)
{
	unsigned long data, text, lib, swap, ptes, pmds;
	unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss;

	/*
	 * Note: to minimize their overhead, mm maintains hiwater_vm and
	 * hiwater_rss only when about to *lower* total_vm or rss.  Any
	 * collector of these hiwater stats must therefore get total_vm
	 * and rss too, which will usually be the higher.  Barriers? not
	 * worth the effort, such snapshots can always be inconsistent.
	 */
	hiwater_vm = total_vm = mm->total_vm;
	if (hiwater_vm < mm->hiwater_vm)
		hiwater_vm = mm->hiwater_vm;
	hiwater_rss = total_rss = get_mm_rss(mm);
	if (hiwater_rss < mm->hiwater_rss)
		hiwater_rss = mm->hiwater_rss;

	data = mm->total_vm - mm->shared_vm - mm->stack_vm;
	text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) >> 10;
	lib = (mm->exec_vm << (PAGE_SHIFT-10)) - text;
	swap = get_mm_counter(mm, MM_SWAPENTS);
	ptes = PTRS_PER_PTE * sizeof(pte_t) * atomic_long_read(&mm->nr_ptes);
	pmds = PTRS_PER_PMD * sizeof(pmd_t) * mm_nr_pmds(mm);
	seq_printf(m,
		"VmPeak:\t%8lu kB\n"
		"VmSize:\t%8lu kB\n"
		"VmLck:\t%8lu kB\n"
		"VmPin:\t%8lu kB\n"
		"VmHWM:\t%8lu kB\n"
		"VmRSS:\t%8lu kB\n"
		"VmData:\t%8lu kB\n"
		"VmStk:\t%8lu kB\n"
		"VmExe:\t%8lu kB\n"
		"VmLib:\t%8lu kB\n"
		"VmPTE:\t%8lu kB\n"
		"VmPMD:\t%8lu kB\n"
		"VmSwap:\t%8lu kB\n",
		hiwater_vm << (PAGE_SHIFT-10),
		total_vm << (PAGE_SHIFT-10),
		mm->locked_vm << (PAGE_SHIFT-10),
		mm->pinned_vm << (PAGE_SHIFT-10),
		hiwater_rss << (PAGE_SHIFT-10),
		total_rss << (PAGE_SHIFT-10),
		data << (PAGE_SHIFT-10),
		mm->stack_vm << (PAGE_SHIFT-10), text, lib,
		ptes >> 10,
		pmds >> 10,
		swap << (PAGE_SHIFT-10));
}

Project: linux
File: task_mmu.c

static void thp_pmd_to_pagemap_entry(pagemap_entry_t *pme, struct pagemapread *pm,
		pmd_t pmd, int offset, int pmd_flags2)
{
	/*
	 * Currently pmd for thp is always present because thp can not be
	 * swapped-out, migrated, or HWPOISONed (split in such cases instead.)
	 * This if-check is just to prepare for future implementation.
	 */
	if (pmd_present(pmd))
		*pme = make_pme(PM_PFRAME(pmd_pfn(pmd) + offset)
				| PM_STATUS2(pm->v2, pmd_flags2) | PM_PRESENT);
	else
		*pme = make_pme(PM_NOT_PRESENT(pm->v2) | PM_STATUS2(pm->v2, pmd_flags2));
}

Project: linux
File: task_mmu.c

static inline void thp_pmd_to_pagemap_entry(pagemap_entry_t *pme, struct pagemapread *pm,
		pmd_t pmd, int offset, int pmd_flags2)
{
}

Project: linux
File: task_mmu.c

static int tid_maps_open(struct inode *inode, struct file *file)
{
	return do_maps_open(inode, file, &proc_tid_maps_op);
}

Project: linux
File: task_mmu.c

static int tid_numa_maps_open(struct inode *inode, struct file *file)
{
	return numa_maps_open(inode, file, &proc_tid_numa_maps_op);
}

Project: linux
File: task_mmu.c

static int tid_smaps_open(struct inode *inode, struct file *file)
{
	return do_maps_open(inode, file, &proc_tid_smaps_op);
}

Project: linux
File: task_mmu.c

static void vma_stop(struct proc_maps_private *priv)
{
	struct mm_struct *mm = priv->mm;

	release_task_mempolicy(priv);
	up_read(&mm->mmap_sem);
	mmput(mm);
}