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. Contrary to the old way
of using kmemleak_ignore() for init.* ELF sections we stick now only to
kmemleak_not_leak() as per suggestion by Catalin Marinas so to avoid
any false positives and simplify the code.
Fixes: ac3b43283923 ("module: replace module_layout with module_memory")
Reported-by: Jim Cromie <[email protected]>
Acked-by: Song Liu <[email protected]>
Suggested-by: Catalin Marinas <[email protected]>
Signed-off-by: Luis Chamberlain <[email protected]>
---
kernel/module/main.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 5cc21083af04..32554d8a5791 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -2231,13 +2231,18 @@ static int move_module(struct module *mod, struct load_info *info)
}
mod->mem[type].size = PAGE_ALIGN(mod->mem[type].size);
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 *could* treat them
+ * slightly differently with kmemleak_ignore() and only grey
+ * them out as they work as typical memory allocations which
+ * *do* eventually get freed, but let's just keep things simple
+ * and avoid *any* false positives.
*/
- kmemleak_ignore(ptr);
+ kmemleak_not_leak(ptr);
if (!ptr) {
t = type;
goto out_enomem;
--
2.39.2
On Thu, Apr 13, 2023 at 10:08:33PM -0700, Luis Chamberlain 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. Contrary to the old way
> of using kmemleak_ignore() for init.* ELF sections we stick now only to
> kmemleak_not_leak() as per suggestion by Catalin Marinas so to avoid
> any false positives and simplify the code.
>
> Fixes: ac3b43283923 ("module: replace module_layout with module_memory")
> Reported-by: Jim Cromie <[email protected]>
> Acked-by: Song Liu <[email protected]>
> Suggested-by: Catalin Marinas <[email protected]>
> Signed-off-by: Luis Chamberlain <[email protected]>
Reviewed-by: Catalin Marinas <[email protected]>