mm/vmalloc.c: avoid bogus -Wmaybe-uninitialized warning

gcc gets confused in pcpu_get_vm_areas() because there are too many
branches that affect whether 'lva' was initialized before it gets used:

  mm/vmalloc.c: In function 'pcpu_get_vm_areas':
  mm/vmalloc.c:991:4: error: 'lva' may be used uninitialized in this function [-Werror=maybe-uninitialized]
      insert_vmap_area_augment(lva, &va->rb_node,
       &free_vmap_area_root, &free_vmap_area_list);
  mm/vmalloc.c:916:20: note: 'lva' was declared here
    struct vmap_area *lva;

Add an intialization to NULL, and check whether this has changed before
the first use.

[ tweak comments]
Fixes: 68ad4a330433 ("mm/vmalloc.c: keep track of free blocks for vmap allocation")
Signed-off-by: Arnd Bergmann <>
Reviewed-by: Uladzislau Rezki (Sony) <>
Cc: Joel Fernandes <>
Signed-off-by: Andrew Morton <>
Signed-off-by: Linus Torvalds <>
1 file changed