On 9/4/24 17:16, Mike Rapoport wrote:
> On Tue, Sep 03, 2024 at 04:20:43PM +0200, Christian Brauner wrote:
>> @@ -275,7 +285,7 @@ do_kmem_cache_create_usercopy(const char *name,
>>
>> mutex_lock(&slab_mutex);
>>
>> - err = kmem_cache_sanity_check(name, size);
>> + err = kmem_cache_sanity_check(name, object_size);
>> if (err) {
>> goto out_unlock;
>> }
>> @@ -296,12 +306,14 @@ do_kmem_cache_create_usercopy(const char *name,
>>
>> /* Fail closed on bad usersize of useroffset values. */
>> if (!IS_ENABLED(CONFIG_HARDENED_USERCOPY) ||
>> - WARN_ON(!usersize && useroffset) ||
>> - WARN_ON(size < usersize || size - usersize < useroffset))
>> - usersize = useroffset = 0;
>> -
>> - if (!usersize)
>> - s = __kmem_cache_alias(name, size, align, flags, ctor);
>> + WARN_ON(!args->usersize && args->useroffset) ||
>> + WARN_ON(object_size < args->usersize ||
>> + object_size - args->usersize < args->useroffset))
>> + args->usersize = args->useroffset = 0;
>> +
>> + if (!args->usersize)
>> + s = __kmem_cache_alias(name, object_size, args->align, flags,
>> + args->ctor);
>
> Sorry I missed it in the previous review, but nothing guaranties that
> nobody will call kmem_cache_create_args with args != NULL.
>
> I think there should be a check for args != NULL and a substitution of args
> with defaults if it actually was NULL.
Hm there might be a bigger problem with this? If we wanted to do a
(non-flag-day) conversion to the new kmem_cache_create() for some callers
that need none of the extra args, passing NULL wouldn't work for the
_Generic((__args) looking for "struct kmem_cache_args *" as NULL is not of
that type, right?
I tried and it really errors out.
