1 files changed, 78 insertions, 1 deletions

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 9f285fb9bab3..0e2899492133 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -134,6 +134,56 @@ static void release_task_mempolicy(struct proc_maps_private *priv)
 }
 #endif
 
+static void seq_print_vma_name(struct seq_file *m, struct vm_area_struct *vma)
+{
+	const char __user *name = vma_get_anon_name(vma);
+	struct mm_struct *mm = vma->vm_mm;
+
+	unsigned long page_start_vaddr;
+	unsigned long page_offset;
+	unsigned long num_pages;
+	unsigned long max_len = NAME_MAX;
+	int i;
+
+	page_start_vaddr = (unsigned long)name & PAGE_MASK;
+	page_offset = (unsigned long)name - page_start_vaddr;
+	num_pages = DIV_ROUND_UP(page_offset + max_len, PAGE_SIZE);
+
+	seq_puts(m, "[anon:");
+
+	for (i = 0; i < num_pages; i++) {
+		int len;
+		int write_len;
+		const char *kaddr;
+		long pages_pinned;
+		struct page *page;
+
+		pages_pinned = get_user_pages(current, mm, page_start_vaddr,
+				1, 0, 0, &page, NULL);
+		if (pages_pinned < 1) {
+			seq_puts(m, "<fault>]");
+			return;
+		}
+
+		kaddr = (const char *)kmap(page);
+		len = min(max_len, PAGE_SIZE - page_offset);
+		write_len = strnlen(kaddr + page_offset, len);
+		seq_write(m, kaddr + page_offset, write_len);
+		kunmap(page);
+		put_page(page);
+
+		/* if strnlen hit a null terminator then we're done */
+		if (write_len != len)
+			break;
+
+		max_len -= len;
+		page_offset = 0;
+		page_start_vaddr += PAGE_SIZE;
+	}
+
+	seq_putc(m, ']');
+}
+
 static void vma_stop(struct proc_maps_private *priv, struct vm_area_struct *vma)
 {
 	if (vma && vma != priv->tail_vma) {
@@ -335,6 +385,12 @@ show_map_vma(struct seq_file *m, struct vm_area_struct *vma, int is_pid)
 				pad_len_spaces(m, len);
 				seq_printf(m, "[stack:%d]", tid);
 			}
+			goto done;
+		}
+
+		if (vma_get_anon_name(vma)) {
+			pad_len_spaces(m, len);
+			seq_print_vma_name(m, vma);
 		}
 	}
 
@@ -634,6 +690,12 @@ static int show_smap(struct seq_file *m, void *v, int is_pid)
 
 	show_smap_vma_flags(m, vma);
 
+	if (vma_get_anon_name(vma)) {
+		seq_puts(m, "Name:           ");
+		seq_print_vma_name(m, vma);
+		seq_putc(m, '\n');
+	}
+
 	if (m->count < m->size)  /* vma is copied successfully */
 		m->version = (vma != get_gate_vma(task->mm))
 			? vma->vm_start : 0;
@@ -722,6 +784,7 @@ static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
 #define CLEAR_REFS_ALL 1
 #define CLEAR_REFS_ANON 2
 #define CLEAR_REFS_MAPPED 3
+#define CLEAR_REFS_MM_HIWATER_RSS 5
 
 static ssize_t clear_refs_write(struct file *file, const char __user *buf,
 				size_t count, loff_t *ppos)
@@ -741,7 +804,8 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
 	rv = kstrtoint(strstrip(buffer), 10, &type);
 	if (rv < 0)
 		return rv;
-	if (type < CLEAR_REFS_ALL || type > CLEAR_REFS_MAPPED)
+	if ((type < CLEAR_REFS_ALL || type > CLEAR_REFS_MAPPED) &&
+	    type != CLEAR_REFS_MM_HIWATER_RSS)
 		return -EINVAL;
 	task = get_proc_task(file_inode(file));
 	if (!task)
@@ -752,6 +816,18 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
 			.pmd_entry = clear_refs_pte_range,
 			.mm = mm,
 		};
+
+		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);
 		for (vma = mm->mmap; vma; vma = vma->vm_next) {
 			clear_refs_walk.private = vma;
@@ -775,6 +851,7 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
 		}
 		flush_tlb_mm(mm);
 		up_read(&mm->mmap_sem);
+out_mm:
 		mmput(mm);
 	}
 	put_task_struct(task);