From 1756954c61cb5c97c618ccb366482b9c1f891d6d Mon Sep 17 00:00:00 2001 From: David Rientjes Date: Fri, 16 Nov 2012 14:14:48 -0800 Subject: mm: fix build warning for uninitialized value do_wp_page() sets mmun_called if mmun_start and mmun_end were initialized and, if so, may call mmu_notifier_invalidate_range_end() with these values. This doesn't prevent gcc from emitting a build warning though: mm/memory.c: In function `do_wp_page': mm/memory.c:2530: warning: `mmun_start' may be used uninitialized in this function mm/memory.c:2531: warning: `mmun_end' may be used uninitialized in this function It's much easier to initialize the variables to impossible values and do a simple comparison to determine if they were initialized to remove the bool entirely. Signed-off-by: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memory.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index fb135ba4aba9..221fc9ffcab1 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2527,9 +2527,8 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, int ret = 0; int page_mkwrite = 0; struct page *dirty_page = NULL; - unsigned long mmun_start; /* For mmu_notifiers */ - unsigned long mmun_end; /* For mmu_notifiers */ - bool mmun_called = false; /* For mmu_notifiers */ + unsigned long mmun_start = 0; /* For mmu_notifiers */ + unsigned long mmun_end = 0; /* For mmu_notifiers */ old_page = vm_normal_page(vma, address, orig_pte); if (!old_page) { @@ -2708,8 +2707,7 @@ gotten: goto oom_free_new; mmun_start = address & PAGE_MASK; - mmun_end = (address & PAGE_MASK) + PAGE_SIZE; - mmun_called = true; + mmun_end = mmun_start + PAGE_SIZE; mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end); /* @@ -2778,7 +2776,7 @@ gotten: page_cache_release(new_page); unlock: pte_unmap_unlock(page_table, ptl); - if (mmun_called) + if (mmun_end > mmun_start) mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end); if (old_page) { /* -- cgit v1.2.3