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

From: tip-bot for Dmitry Safonov
Date: Wed Sep 14 2016 - 15:34:05 EST


Commit-ID: e38447ee1f487eaccdbef4a61dc064f4ae94e2fa
Gitweb: http://git.kernel.org/tip/e38447ee1f487eaccdbef4a61dc064f4ae94e2fa
Author: Dmitry Safonov <dsafonov@xxxxxxxxxxxxx>
AuthorDate: Mon, 5 Sep 2016 16:33:03 +0300
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
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@xxxxxxxxxxxxx>
Acked-by: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: 0x7f454c46@xxxxxxxxx
Cc: oleg@xxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
Cc: gorcunov@xxxxxxxxxx
Cc: xemul@xxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20160905133308.28234-2-dsafonov@xxxxxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

---
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;