From e1640b8c07f4b5b6125fb06fab240e2c125b0c0b Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Sun, 15 Aug 2010 11:35:52 -0700
Subject: [PATCH] --- yaml --- r: 209468 b: refs/heads/master c:
 d7824370e26325c881b665350ce64fb0a4fde24a h: refs/heads/master v: v3

---
 [refs]                   | 2 +-
 trunk/fs/proc/task_mmu.c | 8 +++++++-
 trunk/mm/mlock.c         | 8 ++++++++
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index 46737a9fbe7e..6fb723ce15ac 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 1b68c9596ce17a1e06918ed65fc3d19b92b04aab
+refs/heads/master: d7824370e26325c881b665350ce64fb0a4fde24a
diff --git a/trunk/fs/proc/task_mmu.c b/trunk/fs/proc/task_mmu.c
index aea1d3f1ffb5..439fc1f1c1c4 100644
--- a/trunk/fs/proc/task_mmu.c
+++ b/trunk/fs/proc/task_mmu.c
@@ -210,6 +210,7 @@ static void show_map_vma(struct seq_file *m, struct vm_area_struct *vma)
 	int flags = vma->vm_flags;
 	unsigned long ino = 0;
 	unsigned long long pgoff = 0;
+	unsigned long start;
 	dev_t dev = 0;
 	int len;
 
@@ -220,8 +221,13 @@ static void show_map_vma(struct seq_file *m, struct vm_area_struct *vma)
 		pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
 	}
 
+	/* We don't show the stack guard page in /proc/maps */
+	start = vma->vm_start;
+	if (vma->vm_flags & VM_GROWSDOWN)
+		start += PAGE_SIZE;
+
 	seq_printf(m, "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu %n",
-			vma->vm_start,
+			start,
 			vma->vm_end,
 			flags & VM_READ ? 'r' : '-',
 			flags & VM_WRITE ? 'w' : '-',
diff --git a/trunk/mm/mlock.c b/trunk/mm/mlock.c
index 3f82720e0515..49e5e4cb8232 100644
--- a/trunk/mm/mlock.c
+++ b/trunk/mm/mlock.c
@@ -167,6 +167,14 @@ static long __mlock_vma_pages_range(struct vm_area_struct *vma,
 	if (vma->vm_flags & VM_WRITE)
 		gup_flags |= FOLL_WRITE;
 
+	/* We don't try to access the guard page of a stack vma */
+	if (vma->vm_flags & VM_GROWSDOWN) {
+		if (start == vma->vm_start) {
+			start += PAGE_SIZE;
+			nr_pages--;
+		}
+	}
+
 	while (nr_pages > 0) {
 		int i;