Re: [PATCH] net: Fix __ip_mc_inc_group argument 3 input

[Florian Fainelli <f.fainelli@gmail.com>]

On 8/19/2019 7:25 PM, Li RongQing wrote:
> It expects gfp_t, but got unsigned int mode
> 
> Fixes: 6e2059b53f98 ("ipv4/igmp: init group mode as INCLUDE when join source group")
> Signed-off-by: Li RongQing <lirongqing@baidu.com>
> Signed-off-by: Zhang Yu <zhangyu31@baidu.com>

You have identified a problem, but I don't think it came from this
commit, rather from:

9fb20801dab4 ("net: Fix ip_mc_{dec,inc}_group allocation context")

see below for details.

> ---
>  net/ipv4/igmp.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
> index 180f6896b98b..b8352d716253 100644
> --- a/net/ipv4/igmp.c
> +++ b/net/ipv4/igmp.c
> @@ -1475,7 +1475,7 @@ EXPORT_SYMBOL(__ip_mc_inc_group);
>  
>  void ip_mc_inc_group(struct in_device *in_dev, __be32 addr)
>  {
> -	__ip_mc_inc_group(in_dev, addr, MCAST_EXCLUDE);
> +	__ip_mc_inc_group(in_dev, addr, GFP_KERNEL);

That part looks fine.

>  }
>  EXPORT_SYMBOL(ip_mc_inc_group);
>  
> @@ -2197,7 +2197,7 @@ static int __ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr,
>  	iml->sflist = NULL;
>  	iml->sfmode = mode;
>  	rcu_assign_pointer(inet->mc_list, iml);
> -	__ip_mc_inc_group(in_dev, addr, mode);
> +	__ip_mc_inc_group(in_dev, addr, GFP_KERNEL);

But here, we probably want to pass both mode and gfp_t and use
____ip_mc_inc_group(in_dev, addr, mode, GFP_KERNEL):

diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index 180f6896b98b..2459b5e3fd98 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -2197,7 +2197,7 @@ static int __ip_mc_join_group(struct sock *sk,
struct ip_mreqn *imr,
        iml->sflist = NULL;
        iml->sfmode = mode;
        rcu_assign_pointer(inet->mc_list, iml);
-       __ip_mc_inc_group(in_dev, addr, mode);
+       ____ip_mc_inc_group(in_dev, addr, mode, GFP_KERNEL);
        err = 0;
 done:
        return err;

What do you think?
-- 
Florian