Re: [PATCH net-next RFC 1/2] devlink: Add shared descriptor eswitch attr

[Jiri Pirko <jiri@resnulli.us>]

Wed, Feb 28, 2024 at 02:12:49PM CET, horms@kernel.org wrote:
>On Wed, Feb 28, 2024 at 03:59:53AM +0200, William Tu wrote:
>
>...
>
>> diff --git a/net/devlink/netlink_gen.c b/net/devlink/netlink_gen.c
>> index c81cf2dd154f..ac8b0c7105dd 100644
>> --- a/net/devlink/netlink_gen.c
>> +++ b/net/devlink/netlink_gen.c
>> @@ -194,12 +194,14 @@ static const struct nla_policy devlink_eswitch_get_nl_policy[DEVLINK_ATTR_DEV_NA
>>  };
>>  
>>  /* DEVLINK_CMD_ESWITCH_SET - do */
>> -static const struct nla_policy devlink_eswitch_set_nl_policy[DEVLINK_ATTR_ESWITCH_ENCAP_MODE + 1] = {
>> +static const struct nla_policy devlink_eswitch_set_nl_policy[DEVLINK_ATTR_ESWITCH_SHRDESC_COUNT + 1] = {
>>  	[DEVLINK_ATTR_BUS_NAME] = { .type = NLA_NUL_STRING, },
>>  	[DEVLINK_ATTR_DEV_NAME] = { .type = NLA_NUL_STRING, },
>>  	[DEVLINK_ATTR_ESWITCH_MODE] = NLA_POLICY_MAX(NLA_U16, 1),
>>  	[DEVLINK_ATTR_ESWITCH_INLINE_MODE] = NLA_POLICY_MAX(NLA_U16, 3),
>>  	[DEVLINK_ATTR_ESWITCH_ENCAP_MODE] = NLA_POLICY_MAX(NLA_U8, 1),
>> +	[DEVLINK_ATTR_ESWITCH_SHRDESC_MODE] = NLA_POLICY_MAX(NLA_U8, 1),
>> +	[DEVLINK_ATTR_ESWITCH_SHRDESC_COUNT] = NLA_POLICY_MAX(NLA_U32, 65535),
>>  };
>
>Hi William,
>
>I realise this is probably not central to your purpose in sending an RFC,
>but my understanding is that the max value set using NLA_POLICY_MAX
>is of type s16, and thus 65535 is too large - it becomes -1.
>
>Flagged by W=1 build with clang-17.

First of all:
/* Do not edit directly, auto-generated from: */
/*      Documentation/netlink/specs/devlink.yaml */



>
>>  
>>  /* DEVLINK_CMD_DPIPE_TABLE_GET - do */
>
>...
>