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s390/mm: make pmdp_invalidate() do invalidation only

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Commit 227be799c3 ("s390/mm: uninline pmdp_xxx functions from pgtable.h")
inadvertently changed the behavior of pmdp_invalidate(), so that it now
clears the pmd instead of just marking it as invalid. Fix this by restoring
the original behavior.

A possible impact of the misbehaving pmdp_invalidate() would be the
MADV_DONTNEED races (see commits ced10803 and 58ceeb6b), although we
should not have any negative impact on the related dirty/young flags,
since those flags are not set by the hardware on s390.

Fixes: 227be799c3 ("s390/mm: uninline pmdp_xxx functions from pgtable.h")
Cc: <stable@vger.kernel.org> # v4.6+
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Gerald Schaefer 2017-09-18 16:10:35 +02:00 committed by Martin Schwidefsky
parent 55fb734757
commit 91c575b335
1 changed files with 3 additions and 1 deletions
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4
arch/s390/include/asm/pgtable.h
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@ -1507,7 +1507,9 @@ static inline pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma,
static inline void pmdp_invalidate(struct vm_area_struct *vma,
unsigned long addr, pmd_t *pmdp)
{
pmdp_xchg_direct(vma->vm_mm, addr, pmdp, __pmd(_SEGMENT_ENTRY_EMPTY));
pmd_t pmd = __pmd(pmd_val(*pmdp) | _SEGMENT_ENTRY_INVALID);
pmdp_xchg_direct(vma->vm_mm, addr, pmdp, pmd);
}
#define __HAVE_ARCH_PMDP_SET_WRPROTECT