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| author | David Rientjes <rientjes@google.com> | 2012-11-16 23:14:48 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-11-16 23:33:03 +0100 |
| commit | 1756954c61cb5c97c618ccb366482b9c1f891d6d (patch) | |
| tree | 86a8ab12560d600fa5459218979e72827e0311f5 | |
| parent | mm: add anon_vma_lock to validate_mm() (diff) | |
| download | linux-1756954c61cb5c97c618ccb366482b9c1f891d6d.tar.xz linux-1756954c61cb5c97c618ccb366482b9c1f891d6d.zip | |
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 <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/memory.c | 10 |
1 files 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) { /* |