On Fri, Sep 06, 2024 at 04:38:56PM +0100, Vincent Donnefort wrote:
> commit ac3b43283923 ("module: replace module_layout with module_memory")
> introduced a set of memory regions for the module layout sharing the
> same attributes but didn't update the kmemleak scanned areas which
> intended to limit kmemleak scan to sections containing writable data.
> This means sections such as .text and .rodata are scanned by kmemleak.
>
> Refine the scanned areas for modules by limiting it to MOD_TEXT and
> MOD_INIT_TEXT mod_mem regions.
>
> CC: Song Liu <song@xxxxxxxxxx>
> CC: Catalin Marinas <catalin.marinas@xxxxxxx>
> Signed-off-by: Vincent Donnefort <vdonnefort@xxxxxxxxxx>
>
> diff --git a/kernel/module/debug_kmemleak.c b/kernel/module/debug_kmemleak.c
> index 12a569d361e8..b4cc03842d70 100644
> --- a/kernel/module/debug_kmemleak.c
> +++ b/kernel/module/debug_kmemleak.c
> @@ -12,19 +12,9 @@
> void kmemleak_load_module(const struct module *mod,
> const struct load_info *info)
> {
> - unsigned int i;
> -
> - /* only scan the sections containing data */
> - kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
> -
> - for (i = 1; i < info->hdr->e_shnum; i++) {
> - /* Scan all writable sections that's not executable */
> - if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
> - !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
> - (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
> - continue;
> -
> - kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
> - info->sechdrs[i].sh_size, GFP_KERNEL);
> + /* only scan writable, non-executable sections */
> + for_each_mod_mem_type(type) {
> + if (type != MOD_DATA && type != MOD_INIT_DATA)
> + kmemleak_no_scan(mod->mem[type].base);
> }
> }
I lost track of how module memory allocation works. Is struct module
still scanned after this change?
--
Catalin
