On 8/10/23 09:47, Xiaolei Wang wrote:
> The __stack_depot_save() may be used by some subsystems even before
> the stack depot is initialized.
Does that currently happen, or only after patch 2/2 it starts happening via
kmemleak?
> So add a check of stack_table in
> __stack_depot_save() to make sure no oops in this case.
>
> Fixes: 56a61617dd22 ("mm: use stack_depot for recording kmemleak's backtrace")
In case it's only after 2/2 I don't think this is truly "Fixes"?
> Signed-off-by: Xiaolei Wang <xiaolei.wang@xxxxxxxxxxxxx>
> ---
> lib/stackdepot.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/lib/stackdepot.c b/lib/stackdepot.c
> index 2f5aa851834e..a0651d013a0d 100644
> --- a/lib/stackdepot.c
> +++ b/lib/stackdepot.c
> @@ -376,7 +376,7 @@ depot_stack_handle_t __stack_depot_save(unsigned long *entries,
> */
> nr_entries = filter_irq_stacks(entries, nr_entries);
>
> - if (unlikely(nr_entries == 0) || stack_depot_disabled)
> + if (unlikely(nr_entries == 0) || stack_depot_disabled || unlikely(!stack_table))
> goto fast_exit;
>
> hash = hash_stack(entries, nr_entries);
