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

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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.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Kirill A. Shutemov 2017-02-13 15:52:28 +03:00 committed by Thomas Gleixner
parent 7089db84e3
commit 3ba5b5ea7d
1 changed files with 3 additions and 2 deletions
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5
arch/x86/kernel/vm86_32.c
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@ -160,11 +160,12 @@ void save_v86_state(struct kernel_vm86_regs *regs, int retval)
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_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))