Re: [PATCH mm] kasan: stop leaking stack trace handles

[Andrew Morton]

On Thu, 28 Dec 2023 02:19:51 +0800 kernel test robot <lkp@xxxxxxxxx> wrote:

> Hi,
> 
> kernel test robot noticed the following build warnings:
> 
> [auto build test WARNING on akpm-mm/mm-everything]
> [cannot apply to linus/master v6.7-rc7 next-20231222]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
> 
> url:    https://github.com/intel-lab-lkp/linux/commits/andrey-konovalov-linux-dev/kasan-stop-leaking-stack-trace-handles/20231227-065314
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
> patch link:    https://lore.kernel.org/r/20231226225121.235865-1-andrey.konovalov%40linux.dev
> patch subject: [PATCH mm] kasan: stop leaking stack trace handles
> config: x86_64-randconfig-123-20231227 (https://download.01.org/0day-ci/archive/20231228/202312280213.6j147JJb-lkp@xxxxxxxxx/config)
> compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231228/202312280213.6j147JJb-lkp@xxxxxxxxx/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202312280213.6j147JJb-lkp@xxxxxxxxx/
> 
> All warnings (new ones prefixed by >>):
> 
> >> mm/kasan/generic.c:506:6: warning: no previous prototype for 'release_alloc_meta' [-Wmissing-prototypes]
>      506 | void release_alloc_meta(struct kasan_alloc_meta *meta)
>          |      ^~~~~~~~~~~~~~~~~~
> >> mm/kasan/generic.c:517:6: warning: no previous prototype for 'release_free_meta' [-Wmissing-prototypes]
>      517 | void release_free_meta(const void *object, struct kasan_free_meta *meta)
>          |      ^~~~~~~~~~~~~~~~~

Thanks, I added this fix:

--- a/mm/kasan/generic.c~kasan-stop-leaking-stack-trace-handles-fix
+++ a/mm/kasan/generic.c
@@ -503,7 +503,7 @@ void kasan_init_object_meta(struct kmem_
 	 */
 }
 
-void release_alloc_meta(struct kasan_alloc_meta *meta)
+static void release_alloc_meta(struct kasan_alloc_meta *meta)
 {
 	/* Evict the stack traces from stack depot. */
 	stack_depot_put(meta->alloc_track.stack);
@@ -514,7 +514,7 @@ void release_alloc_meta(struct kasan_all
 	__memset(meta, 0, sizeof(*meta));
 }
 
-void release_free_meta(const void *object, struct kasan_free_meta *meta)
+static void release_free_meta(const void *object, struct kasan_free_meta *meta)
 {
 	/* Check if free meta is valid. */
 	if (*(u8 *)kasan_mem_to_shadow(object) != KASAN_SLAB_FREE_META)
_