The patch titled
mm: fix uninitialized variables for find_vma_prepare callers
has been added to the -mm tree. Its filename is
mm-fix-uninitialized-variables-for-find_vma_prepare-callers.patch
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------------------------------------------------------
Subject: mm: fix uninitialized variables for find_vma_prepare callers
From: Benny Halevy <bhalevy@xxxxxxxxxxx>
gcc 4.3.0 correctly emits the following warnings.
When a vma covering addr is found, find_vma_prepare indeed returns without
setting pprev, rb_link, and rb_parent.
/usr0/export/dev/bhalevy/git/linux-pnfs-bh-nfs41/mm/mmap.c: In function `insert_vm_struct':
/usr0/export/dev/bhalevy/git/linux-pnfs-bh-nfs41/mm/mmap.c:2085: warning: `rb_parent' may be used uninitialized in this function
/usr0/export/dev/bhalevy/git/linux-pnfs-bh-nfs41/mm/mmap.c:2085: warning: `rb_link' may be used uninitialized in this function
/usr0/export/dev/bhalevy/git/linux-pnfs-bh-nfs41/mm/mmap.c:2084: warning: `prev' may be used uninitialized in this function
/usr0/export/dev/bhalevy/git/linux-pnfs-bh-nfs41/mm/mmap.c: In function `copy_vma':
/usr0/export/dev/bhalevy/git/linux-pnfs-bh-nfs41/mm/mmap.c:2124: warning: `rb_parent' may be used uninitialized in this function
/usr0/export/dev/bhalevy/git/linux-pnfs-bh-nfs41/mm/mmap.c:2124: warning: `rb_link' may be used uninitialized in this function
/usr0/export/dev/bhalevy/git/linux-pnfs-bh-nfs41/mm/mmap.c:2123: warning: `prev' may be used uninitialized in this function
/usr0/export/dev/bhalevy/git/linux-pnfs-bh-nfs41/mm/mmap.c: In function `do_brk':
/usr0/export/dev/bhalevy/git/linux-pnfs-bh-nfs41/mm/mmap.c:1951: warning: `rb_parent' may be used uninitialized in this function
/usr0/export/dev/bhalevy/git/linux-pnfs-bh-nfs41/mm/mmap.c:1951: warning: `rb_link' may be used uninitialized in this function
/usr0/export/dev/bhalevy/git/linux-pnfs-bh-nfs41/mm/mmap.c:1949: warning: `prev' may be used uninitialized in this function
/usr0/export/dev/bhalevy/git/linux-pnfs-bh-nfs41/mm/mmap.c: In function `mmap_region':
/usr0/export/dev/bhalevy/git/linux-pnfs-bh-nfs41/mm/mmap.c:1092: warning: `rb_parent' may be used uninitialized in this function
/usr0/export/dev/bhalevy/git/linux-pnfs-bh-nfs41/mm/mmap.c:1092: warning: `rb_link' may be used uninitialized in this function
/usr0/export/dev/bhalevy/git/linux-pnfs-bh-nfs41/mm/mmap.c:1089: warning: `prev' may be used uninitialized in this function
Hugh adds: in fact, none of find_vma_prepare's callers use those values
when a vma is found to be already covering addr, it's either an error or
an occasion to munmap and repeat. Okay, let's quieten the compiler (but I
would prefer it if pprev, rb_link and rb_parent were meaningful in that
case, rather than whatever's in them from descending the tree).
Signed-off-by: Benny Halevy <bhalevy@xxxxxxxxxxx>
Signed-off-by: Hugh Dickins <hugh@xxxxxxxxxxx>
Cc: "Ryan Hope" <rmh3093@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mmap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff -puN mm/mmap.c~mm-fix-uninitialized-variables-for-find_vma_prepare-callers mm/mmap.c
--- a/mm/mmap.c~mm-fix-uninitialized-variables-for-find_vma_prepare-callers
+++ a/mm/mmap.c
@@ -370,7 +370,7 @@ find_vma_prepare(struct mm_struct *mm, u
if (vma_tmp->vm_end > addr) {
vma = vma_tmp;
if (vma_tmp->vm_start <= addr)
- return vma;
+ break;
__rb_link = &__rb_parent->rb_left;
} else {
rb_prev = __rb_parent;
_
Patches currently in -mm which might be from bhalevy@xxxxxxxxxxx are
mm-fix-uninitialized-variables-for-find_vma_prepare-callers.patch
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