Re: [PATCH 6.1.y] net: napi: Prevent overflow of napi_defer_hard_irqs

[Sasha Levin <sashal@kernel.org>]

[ Sasha's backport helper bot ]

Hi,

The upstream commit SHA1 provided is correct: 08062af0a52107a243f7608fd972edb54ca5b7f8

WARNING: Author mismatch between patch and upstream commit:
Backport author: <jianqi.ren.cn@windriver.com>
Commit author: Joe Damato <jdamato@fastly.com>


Status in newer kernel trees:
6.12.y | Present (exact SHA1)
6.6.y | Not found
6.1.y | Not found

Note: The patch differs from the upstream commit:
---
1:  08062af0a5210 ! 1:  06c1e1d149b4f net: napi: Prevent overflow of napi_defer_hard_irqs
    @@ Metadata
      ## Commit message ##
         net: napi: Prevent overflow of napi_defer_hard_irqs
     
    +    [ Upstream commit 08062af0a52107a243f7608fd972edb54ca5b7f8 ]
    +
         In commit 6f8b12d661d0 ("net: napi: add hard irqs deferral feature")
         napi_defer_irqs was added to net_device and napi_defer_irqs_count was
         added to napi_struct, both as type int.
    @@ Commit message
         Reviewed-by: Eric Dumazet <edumazet@google.com>
         Link: https://patch.msgid.link/20240904153431.307932-1-jdamato@fastly.com
         Signed-off-by: Jakub Kicinski <kuba@kernel.org>
    -
    - ## Documentation/networking/net_cachelines/net_device.rst ##
    -@@ Documentation/networking/net_cachelines/net_device.rst: unsigned_int                        num_rx_queues
    - unsigned_int                        real_num_rx_queues      -                   read_mostly         get_rps_cpu
    - struct_bpf_prog*                    xdp_prog                -                   read_mostly         netif_elide_gro()
    - unsigned_long                       gro_flush_timeout       -                   read_mostly         napi_complete_done
    --int                                 napi_defer_hard_irqs    -                   read_mostly         napi_complete_done
    -+u32                                 napi_defer_hard_irqs    -                   read_mostly         napi_complete_done
    - unsigned_int                        gro_max_size            -                   read_mostly         skb_gro_receive
    - unsigned_int                        gro_ipv4_max_size       -                   read_mostly         skb_gro_receive
    - rx_handler_func_t*                  rx_handler              read_mostly         -                   __netif_receive_skb_core
    +    Signed-off-by: Jianqi Ren <jianqi.ren.cn@windriver.com>
     
      ## include/linux/netdevice.h ##
     @@ include/linux/netdevice.h: struct napi_struct {
    @@ include/linux/netdevice.h: struct napi_struct {
      	int			(*poll)(struct napi_struct *, int);
      #ifdef CONFIG_NETPOLL
     @@ include/linux/netdevice.h: struct net_device {
    - 	unsigned int		real_num_rx_queues;
    - 	struct netdev_rx_queue	*_rx;
    + 
    + 	struct bpf_prog __rcu	*xdp_prog;
      	unsigned long		gro_flush_timeout;
     -	int			napi_defer_hard_irqs;
     +	u32			napi_defer_hard_irqs;
    - 	unsigned int		gro_max_size;
    - 	unsigned int		gro_ipv4_max_size;
    - 	rx_handler_func_t __rcu	*rx_handler;
    + #define GRO_LEGACY_MAX_SIZE	65536u
    + /* TCP minimal MSS is 8 (TCP_MIN_GSO_SIZE),
    +  * and shinfo->gso_segs is a 16bit field.
     
      ## net/core/net-sysfs.c ##
     @@
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.1.y        |  Success    |  Success   |