> On Mar 28, 2023, at 18:14, Marco Elver <elver@xxxxxxxxxx> wrote:
>
> On Tue, 28 Mar 2023 at 11:58, 'Muchun Song' via kasan-dev
> <kasan-dev@xxxxxxxxxxxxxxxx> wrote:
>>
>> Check kfence pool size at building time to expose problem ASAP.
>>
>> Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
>> ---
>> mm/kfence/core.c | 7 +++----
>> 1 file changed, 3 insertions(+), 4 deletions(-)
>>
>> diff --git a/mm/kfence/core.c b/mm/kfence/core.c
>> index de62a84d4830..6781af1dfa66 100644
>> --- a/mm/kfence/core.c
>> +++ b/mm/kfence/core.c
>> @@ -841,10 +841,9 @@ static int kfence_init_late(void)
>> return -ENOMEM;
>> __kfence_pool = page_to_virt(pages);
>> #else
>> - if (nr_pages > MAX_ORDER_NR_PAGES) {
>> - pr_warn("KFENCE_NUM_OBJECTS too large for buddy allocator\n");
>> - return -EINVAL;
>> - }
>> + BUILD_BUG_ON_MSG(get_order(KFENCE_POOL_SIZE) > MAX_ORDER,
>> + "CONFIG_KFENCE_NUM_OBJECTS is too large for buddy allocator");
>> +
>
> It's perfectly valid to want to use KFENCE with a very large pool that
> is initialized on boot, and simply sacrifice the ability to initialize
> late.
You are right. I didn’t realize this.
Thanks
>
> Nack.
