3 files changed, 20 insertions, 97 deletions

diff --git a/fs/proc/array.c b/fs/proc/array.c
index f560325c444..13b5d070817 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -327,94 +327,6 @@ static inline void task_context_switch_counts(struct seq_file *m,
 			p->nivcsw);
 }
 
-#ifdef CONFIG_MMU
-
-struct stack_stats {
-	struct vm_area_struct *vma;
-	unsigned long	startpage;
-	unsigned long	usage;
-};
-
-static int stack_usage_pte_range(pmd_t *pmd, unsigned long addr,
-				unsigned long end, struct mm_walk *walk)
-{
-	struct stack_stats *ss = walk->private;
-	struct vm_area_struct *vma = ss->vma;
-	pte_t *pte, ptent;
-	spinlock_t *ptl;
-	int ret = 0;
-
-	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
-	for (; addr != end; pte++, addr += PAGE_SIZE) {
-		ptent = *pte;
-
-#ifdef CONFIG_STACK_GROWSUP
-		if (pte_present(ptent) || is_swap_pte(ptent))
-			ss->usage = addr - ss->startpage + PAGE_SIZE;
-#else
-		if (pte_present(ptent) || is_swap_pte(ptent)) {
-			ss->usage = ss->startpage - addr + PAGE_SIZE;
-			pte++;
-			ret = 1;
-			break;
-		}
-#endif
-	}
-	pte_unmap_unlock(pte - 1, ptl);
-	cond_resched();
-	return ret;
-}
-
-static inline unsigned long get_stack_usage_in_bytes(struct vm_area_struct *vma,
-				struct task_struct *task)
-{
-	struct stack_stats ss;
-	struct mm_walk stack_walk = {
-		.pmd_entry = stack_usage_pte_range,
-		.mm = vma->vm_mm,
-		.private = &ss,
-	};
-
-	if (!vma->vm_mm || is_vm_hugetlb_page(vma))
-		return 0;
-
-	ss.vma = vma;
-	ss.startpage = task->stack_start & PAGE_MASK;
-	ss.usage = 0;
-
-#ifdef CONFIG_STACK_GROWSUP
-	walk_page_range(KSTK_ESP(task) & PAGE_MASK, vma->vm_end,
-		&stack_walk);
-#else
-	walk_page_range(vma->vm_start, (KSTK_ESP(task) & PAGE_MASK) + PAGE_SIZE,
-		&stack_walk);
-#endif
-	return ss.usage;
-}
-
-static inline void task_show_stack_usage(struct seq_file *m,
-						struct task_struct *task)
-{
-	struct vm_area_struct	*vma;
-	struct mm_struct	*mm = get_task_mm(task);
-
-	if (mm) {
-		down_read(&mm->mmap_sem);
-		vma = find_vma(mm, task->stack_start);
-		if (vma)
-			seq_printf(m, "Stack usage:\t%lu kB\n",
-				get_stack_usage_in_bytes(vma, task) >> 10);
-
-		up_read(&mm->mmap_sem);
-		mmput(mm);
-	}
-}
-#else
-static void task_show_stack_usage(struct seq_file *m, struct task_struct *task)
-{
-}
-#endif		/* CONFIG_MMU */
-
 static void task_cpus_allowed(struct seq_file *m, struct task_struct *task)
 {
 	seq_printf(m, "Cpus_allowed:\t");
@@ -445,7 +357,6 @@ int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
 	task_show_regs(m, task);
 #endif
 	task_context_switch_counts(m, task);
-	task_show_stack_usage(m, task);
 	return 0;
 }
 
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 18d5cc62d8e..58324c29916 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1419,7 +1419,6 @@ static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
 		goto out;
 
 	error = PROC_I(inode)->op.proc_get_link(inode, &nd->path);
-	nd->last_type = LAST_BIND;
 out:
 	return ERR_PTR(error);
 }
@@ -2370,16 +2369,30 @@ static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
 {
 	struct pid_namespace *ns = dentry->d_sb->s_fs_info;
 	pid_t tgid = task_tgid_nr_ns(current, ns);
-	char tmp[PROC_NUMBUF];
-	if (!tgid)
-		return ERR_PTR(-ENOENT);
-	sprintf(tmp, "%d", task_tgid_nr_ns(current, ns));
-	return ERR_PTR(vfs_follow_link(nd,tmp));
+	char *name = ERR_PTR(-ENOENT);
+	if (tgid) {
+		name = __getname();
+		if (!name)
+			name = ERR_PTR(-ENOMEM);
+		else
+			sprintf(name, "%d", tgid);
+	}
+	nd_set_link(nd, name);
+	return NULL;
+}
+
+static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd,
+				void *cookie)
+{
+	char *s = nd_get_link(nd);
+	if (!IS_ERR(s))
+		__putname(s);
 }
 
 static const struct inode_operations proc_self_inode_operations = {
 	.readlink	= proc_self_readlink,
 	.follow_link	= proc_self_follow_link,
+	.put_link	= proc_self_put_link,
 };
 
 /*
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 47c03f4336b..f277c4a111c 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -361,12 +361,11 @@ static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
 		if (!pte_present(ptent))
 			continue;
 
-		mss->resident += PAGE_SIZE;
-
 		page = vm_normal_page(vma, addr, ptent);
 		if (!page)
 			continue;
 
+		mss->resident += PAGE_SIZE;
 		/* Accumulate the size in pages that have been accessed. */
 		if (pte_young(ptent) || PageReferenced(page))
 			mss->referenced += PAGE_SIZE;