[PATCH 2/3] Fix /proc/pid/pagemap header copy to userspace

[boutcher@cs.umn.edu (Dave Boutcher)]

Earlier code relied on a broken length calculation copy
/proc/pid/pagemap header data to userspace.  This fix
correctly calls the add_to_pagemap routine after the header data is
set to copy results to userspace in a sane fashion.

Signed-off-by: Dave Boutcher <boutcher@cs.umn.edu>
---
 fs/proc/task_mmu.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index b2baeab..1f78cb4 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -657,11 +657,11 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
 	pm.out = buf;
 
 	if (svpfn == -1) {
-		add_to_pagemap(pm.next, 0, &pm);
 		((char *)page)[0] = (ntohl(1) != 1);
 		((char *)page)[1] = PAGE_SHIFT;
 		((char *)page)[2] = sizeof(unsigned long);
 		((char *)page)[3] = sizeof(unsigned long);
+		add_to_pagemap(pm.next, page[0], &pm);
 	}
 
 	down_read(&mm->mmap_sem);
-- 
1.4.4.2