uprobes: __replace_page() needs munlock_vma_page()
Like do_wp_page(), __replace_page() should do munlock_vma_page()
for the case when the old page still has other !VM_LOCKED
mappings. Unfortunately this needs mm/internal.h.
Also, move put_page() outside of ptl lock. This doesn't really
matter but looks a bit better.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar.vnet.ibm.com>
Cc: Anton Arapov <anton@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20120729182249.GA20372@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index bb30a4f..c08a22d 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -32,6 +32,7 @@
#include <linux/swap.h> /* try_to_free_swap */
#include <linux/ptrace.h> /* user_enable_single_step */
#include <linux/kdebug.h> /* notifier mechanism */
+#include "../../mm/internal.h" /* munlock_vma_page */
#include <linux/uprobes.h>
@@ -141,7 +142,7 @@
pte_t *ptep;
int err;
- /* freeze PageSwapCache() for try_to_free_swap() below */
+ /* For try_to_free_swap() and munlock_vma_page() below */
lock_page(page);
err = -EAGAIN;
@@ -164,9 +165,12 @@
page_remove_rmap(page);
if (!page_mapped(page))
try_to_free_swap(page);
- put_page(page);
pte_unmap_unlock(ptep, ptl);
+ if (vma->vm_flags & VM_LOCKED)
+ munlock_vma_page(page);
+ put_page(page);
+
err = 0;
unlock:
unlock_page(page);