On Wed, 5 Nov 2014, Andrey Ryabinin wrote:
> Adding __printf(3, 4) to slab_err exposed following:
>
> mm/slub.c: In function ‘check_slab’:
> mm/slub.c:852:4: warning: format ‘%u’ expects argument of type ‘unsigned int’, but argument 4 has type ‘const char *’ [-Wformat=]
> s->name, page->objects, maxobj);
> ^
> mm/slub.c:852:4: warning: too many arguments for format [-Wformat-extra-args]
> mm/slub.c:857:4: warning: format ‘%u’ expects argument of type ‘unsigned int’, but argument 4 has type ‘const char *’ [-Wformat=]
> s->name, page->inuse, page->objects);
> ^
> mm/slub.c:857:4: warning: too many arguments for format [-Wformat-extra-args]
>
Wow, that's an ancient issue, thanks for finding it.
> mm/slub.c: In function ‘on_freelist’:
> mm/slub.c:905:4: warning: format ‘%d’ expects argument of type ‘int’, but argument 5 has type ‘long unsigned int’ [-Wformat=]
> "should be %d", page->objects, max_objects);
>
> Signed-off-by: Andrey Ryabinin <a.ryabinin@xxxxxxxxxxx>
> Cc: Christoph Lameter <cl@xxxxxxxxx>
> Cc: Pekka Enberg <penberg@xxxxxxxxxx>
> Cc: David Rientjes <rientjes@xxxxxxxxxx>
> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
> ---
> mm/slub.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/mm/slub.c b/mm/slub.c
> index 80c170e..850a94a 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -849,12 +849,12 @@ static int check_slab(struct kmem_cache *s, struct page *page)
> maxobj = order_objects(compound_order(page), s->size, s->reserved);
> if (page->objects > maxobj) {
> slab_err(s, page, "objects %u > max %u",
> - s->name, page->objects, maxobj);
> + page->objects, maxobj);
> return 0;
> }
> if (page->inuse > page->objects) {
> slab_err(s, page, "inuse %u > max %u",
> - s->name, page->inuse, page->objects);
> + page->inuse, page->objects);
> return 0;
> }
> /* Slab_pad_check fixes things up after itself */
> @@ -902,7 +902,7 @@ static int on_freelist(struct kmem_cache *s, struct page *page, void *search)
>
> if (page->objects != max_objects) {
> slab_err(s, page, "Wrong number of objects. Found %d but "
> - "should be %d", page->objects, max_objects);
> + "should be %ld", page->objects, max_objects);
> page->objects = max_objects;
> slab_fix(s, "Number of objects adjusted.");
> }
Instead of this hunk, I think that max_objects should be declared as int
rather than unsigned long since that's what order_objects() returns and it
is being compared to page->objects which is also int.