[PATCH] Initialise mmu_notifier_range correctly

From: Matthew Wilcox
Date: Wed Jan 02 2019 - 19:21:33 EST



One of the paths in follow_pte_pmd() initialised the mmu_notifier_range
incorrectly.

Signed-off-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Fixes: ac46d4f3c432 ("mm/mmu_notifier: use structure for invalidate_range_start/end calls v2")
Tested-by: Dave Chinner <dchinner@xxxxxxxxxx>

diff --git a/mm/memory.c b/mm/memory.c
index 2dd2f9ab57f4..21a650368be0 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4078,8 +4078,8 @@ static int __follow_pte_pmd(struct mm_struct *mm, unsigned long address,
goto out;

if (range) {
- range->start = address & PAGE_MASK;
- range->end = range->start + PAGE_SIZE;
+ mmu_notifier_range_init(range, mm, address & PAGE_MASK,
+ (address & PAGE_MASK) + PAGE_SIZE);
mmu_notifier_invalidate_range_start(range);
}
ptep = pte_offset_map_lock(mm, pmd, address, ptlp);