On Tue, Apr 4, 2023 at 7:27 PM Luis Chamberlain <mcgrof@xxxxxxxxxx> wrote:
>
> Commit ac3b43283923 ("module: replace module_layout with module_memory")
> reworked the way to handle memory allocations to make it clearer. But it
> lost in translation how we handled kmemleak_ignore() or kmemleak_not_leak()
> for different ELF sections.
>
> Fix this and clarify the comments a bit more.
>
> Fixes: ac3b43283923 ("module: replace module_layout with module_memory")
> Reported-by: Jim Cromie <jim.cromie@xxxxxxxxx>
> Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Acked-by: Song Liu <song@xxxxxxxxxx>
Thanks for the fix!
> ---
> kernel/module/main.c | 20 ++++++++++++++++----
> 1 file changed, 16 insertions(+), 4 deletions(-)
>
> diff --git a/kernel/module/main.c b/kernel/module/main.c
> index 5cc21083af04..d8bb23fa6989 100644
> --- a/kernel/module/main.c
> +++ b/kernel/module/main.c
> @@ -2233,11 +2233,23 @@ static int move_module(struct module *mod, struct load_info *info)
> ptr = module_memory_alloc(mod->mem[type].size, type);
>
> /*
> - * The pointer to this block is stored in the module structure
> - * which is inside the block. Just mark it as not being a
> - * leak.
> + * The pointer to these blocks of memory are stored on the module
> + * structure and we keep that around so long as the module is
> + * around. We only free that memory when we unload the module.
> + * Just mark them as not being a leak then. The .init* ELF
> + * sections *do* get freed after boot so we treat them slightly
> + * differently and only grey them out -- they work as typical
> + * memory allocations which *do* eventually get freed.
> */
> - kmemleak_ignore(ptr);
> + switch (type) {
> + case MOD_INIT_TEXT: /* fallthrough */
> + case MOD_INIT_DATA: /* fallthrough */
> + case MOD_INIT_RODATA: /* fallthrough */
> + kmemleak_ignore(ptr);
> + break;
> + default:
> + kmemleak_not_leak(ptr);
> + }
> if (!ptr) {
> t = type;
> goto out_enomem;
> --
> 2.39.2
>
