This is a note to let you know that I've just added the patch titled

x86/vm86: Fix unused variable warning if THP is disabled

to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: x86-vm86-fix-unused-variable-warning-if-thp-is-disabled.patch and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From 3ba5b5ea7dc3a10ef50819b43a9f8de2705f4eec Mon Sep 17 00:00:00 2001

From: "Kirill A. Shutemov" kirill.shutemov@linux.intel.com Date: Mon, 13 Feb 2017 15:52:28 +0300 Subject: x86/vm86: Fix unused variable warning if THP is disabled MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit

From: Kirill A. Shutemov kirill.shutemov@linux.intel.com

commit 3ba5b5ea7dc3a10ef50819b43a9f8de2705f4eec upstream.

GCC complains about unused variable 'vma' in mark_screen_rdonly() if THP is disabled:

arch/x86/kernel/vm86_32.c: In function ‘mark_screen_rdonly’: arch/x86/kernel/vm86_32.c:180:26: warning: unused variable ‘vma’ [-Wunused-variable] struct vm_area_struct *vma = find_vma(mm, 0xA0000);

That's silly. pmd_trans_huge() resolves to 0 when THP is disabled, so the whole block should be eliminated.

Moving the variable declaration outside the if() block shuts GCC up.

Reported-by: Jérémy Lefaure jeremy.lefaure@lse.epita.fr Signed-off-by: Kirill A. Shutemov kirill.shutemov@linux.intel.com Tested-by: Borislav Petkov bp@suse.de Cc: Carlos O'Donell carlos@redhat.com Link: http://lkml.kernel.org/r/20170213125228.63645-1-kirill.shutemov@linux.intel.... Signed-off-by: Thomas Gleixner tglx@linutronix.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- arch/x86/kernel/vm86_32.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)

--- a/arch/x86/kernel/vm86_32.c +++ b/arch/x86/kernel/vm86_32.c @@ -160,11 +160,12 @@ void save_v86_state(struct kernel_vm86_r

static void mark_screen_rdonly(struct mm_struct *mm) { + struct vm_area_struct *vma; + spinlock_t *ptl; pgd_t *pgd; pud_t *pud; pmd_t *pmd; pte_t *pte; - spinlock_t *ptl; int i;

down_write(&mm->mmap_sem); @@ -177,7 +178,7 @@ static void mark_screen_rdonly(struct mm pmd = pmd_offset(pud, 0xA0000);

if (pmd_trans_huge(*pmd)) { - struct vm_area_struct *vma = find_vma(mm, 0xA0000); + vma = find_vma(mm, 0xA0000); split_huge_pmd(vma, pmd, 0xA0000); } if (pmd_none_or_clear_bad(pmd))

Patches currently in stable-queue which might be from kirill.shutemov@linux.intel.com are

queue-4.9/x86-vm86-fix-unused-variable-warning-if-thp-is-disabled.patch queue-4.9/shmem-avoid-maybe-uninitialized-warning.patch