[tip:x86/vdso] x86/vdso: Unmap vdso blob on vvar mapping failure

[tip-bot for Dmitry Safonov <tipbot@zytor.com>]

Commit-ID:  e38447ee1f487eaccdbef4a61dc064f4ae94e2fa
Gitweb:     http://git.kernel.org/tip/e38447ee1f487eaccdbef4a61dc064f4ae94e2fa
Author:     Dmitry Safonov <dsafonov@virtuozzo.com>
AuthorDate: Mon, 5 Sep 2016 16:33:03 +0300
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Wed, 14 Sep 2016 21:28:08 +0200

x86/vdso: Unmap vdso blob on vvar mapping failure

If remapping of vDSO blob failed on vvar mapping,
we need to unmap previously mapped vDSO blob.

Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: 0x7f454c46@gmail.com
Cc: oleg@redhat.com
Cc: linux-mm@kvack.org
Cc: gorcunov@openvz.org
Cc: xemul@virtuozzo.com
Link: http://lkml.kernel.org/r/20160905133308.28234-2-dsafonov@virtuozzo.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

---
 arch/x86/entry/vdso/vma.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index f840766..3bab6ba 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -238,12 +238,14 @@ static int map_vdso(const struct vdso_image *image, bool calculate_addr)
 
 	if (IS_ERR(vma)) {
 		ret = PTR_ERR(vma);
-		goto up_fail;
+		do_munmap(mm, text_start, image->size);
 	}
 
 up_fail:
-	if (ret)
+	if (ret) {
 		current->mm->context.vdso = NULL;
+		current->mm->context.vdso_image = NULL;
+	}
 
 	up_write(&mm->mmap_sem);
 	return ret;