mm: fix uninitialized variables for find_vma_prepare callers

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.

  mm/mmap.c: In function `insert_vm_struct':
  mm/mmap.c:2085: warning: `rb_parent' may be used uninitialized in this function
  mm/mmap.c:2085: warning: `rb_link' may be used uninitialized in this function
  mm/mmap.c:2084: warning: `prev' may be used uninitialized in this function
  mm/mmap.c: In function `copy_vma':
  mm/mmap.c:2124: warning: `rb_parent' may be used uninitialized in this function
  mm/mmap.c:2124: warning: `rb_link' may be used uninitialized in this function
  mm/mmap.c:2123: warning: `prev' may be used uninitialized in this function
  mm/mmap.c: In function `do_brk':
  mm/mmap.c:1951: warning: `rb_parent' may be used uninitialized in this function
  mm/mmap.c:1951: warning: `rb_link' may be used uninitialized in this function
  mm/mmap.c:1949: warning: `prev' may be used uninitialized in this function
  mm/mmap.c: In function `mmap_region':
  mm/mmap.c:1092: warning: `rb_parent' may be used uninitialized in this function
  mm/mmap.c:1092: warning: `rb_link' may be used uninitialized in this function
  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 <[email protected]>
Signed-off-by: Hugh Dickins <[email protected]>
Cc: "Ryan Hope" <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions