On Tue, Aug 15, 2023 at 01:13:57PM +0800, Xiaolei Wang wrote:
> kmemleak_initialized is set in kmemleak_late_init(), which
> also means that there is no call trace which object's memory
> leak is before kmemleak_late_init(), so use object_cache instead
> of kmemleak_initialized to check in set_track_prepare() to avoid
> no call trace records when there is a memory leak in the code
> between kmemleak_init() and kmemleak_late_init().
>
> unreferenced object 0xc674ca80 (size 64):
> comm "swapper/0", pid 1, jiffies 4294938337 (age 204.880s)
> hex dump (first 32 bytes):
> 80 55 75 c6 80 54 75 c6 00 55 75 c6 80 52 75 c6 .Uu..Tu..Uu..Ru.
> 00 53 75 c6 00 00 00 00 00 00 00 00 00 00 00 00 .Su..........
>
> Fixes: 56a61617dd22 ("mm: use stack_depot for recording kmemleak's backtrace")
> Signed-off-by: Xiaolei Wang <xiaolei.wang@xxxxxxxxxxxxx>
> ---
> mm/kmemleak.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/mm/kmemleak.c b/mm/kmemleak.c
> index a2d34226e3c8..04bb4cdbb402 100644
> --- a/mm/kmemleak.c
> +++ b/mm/kmemleak.c
> @@ -610,7 +610,8 @@ static noinline depot_stack_handle_t set_track_prepare(void)
> unsigned long entries[MAX_TRACE];
> unsigned int nr_entries;
>
> - if (!kmemleak_initialized)
> + /*Use object_cache to determine whether kmemleak_init() is complete*/
Nitpick: please add spaces after/before the comment delimiters. I'd also
make it clearer that it's not about kmemleak being initialised but
rather the stack depot. E.g.:
/*
* Use object_cache to determine whether kmemleak_init() has
* been invoked. stack_depot_early_init() is called before
* kmemleak_init() in mm_core_init().
*/
> + if (!object_cache)
> return 0;
> nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 3);
> trace_handle = stack_depot_save(entries, nr_entries, GFP_NOWAIT);
Otherwise:
Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>
