Re: [tipc-discussion] [net-next] Revert "tipc: use consistent GFP flags"

[Jon M. <jm...@re...>]

On 12/10/21 01:59, Hoang Le wrote:
> This reverts commit 86c3a3e964d910a62eeb277d60b2a60ebefa9feb.
>
> The tipc_aead_init() function can be calling from an interrupt routine.
> This allocation might sleep with GFP_KERNEL flag, hence the following BUG
> is reported.
>
> [   17.657509] BUG: sleeping function called from invalid context at include/linux/sched/mm.h:230
> [   17.660916] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 0, name: swapper/3
> [   17.664093] preempt_count: 302, expected: 0
> [   17.665619] RCU nest depth: 2, expected: 0
> [   17.667163] Preemption disabled at:
> [   17.667165] [<0000000000000000>] 0x0
> [   17.669753] CPU: 3 PID: 0 Comm: swapper/3 Kdump: loaded Tainted: G        W         5.16.0-rc4+ #1
> [   17.673006] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
> [   17.675540] Call Trace:
> [   17.676285]  <IRQ>
> [   17.676913]  dump_stack_lvl+0x34/0x44
> [   17.678033]  __might_resched.cold+0xd6/0x10f
> [   17.679311]  kmem_cache_alloc_trace+0x14d/0x220
> [   17.680663]  tipc_crypto_start+0x4a/0x2b0 [tipc]
> [   17.682146]  ? kmem_cache_alloc_trace+0xd3/0x220
> [   17.683545]  tipc_node_create+0x2f0/0x790 [tipc]
> [   17.684956]  tipc_node_check_dest+0x72/0x680 [tipc]
> [   17.686706]  ? ___cache_free+0x31/0x350
> [   17.688008]  ? skb_release_data+0x128/0x140
> [   17.689431]  tipc_disc_rcv+0x479/0x510 [tipc]
> [   17.690904]  tipc_rcv+0x71c/0x730 [tipc]
> [   17.692219]  ? __netif_receive_skb_core+0xb7/0xf60
> [   17.693856]  tipc_l2_rcv_msg+0x5e/0x90 [tipc]
> [   17.695333]  __netif_receive_skb_list_core+0x20b/0x260
> [   17.697072]  netif_receive_skb_list_internal+0x1bf/0x2e0
> [   17.698870]  ? dev_gro_receive+0x4c2/0x680
> [   17.700255]  napi_complete_done+0x6f/0x180
> [   17.701657]  virtnet_poll+0x29c/0x42e [virtio_net]
> [   17.703262]  __napi_poll+0x2c/0x170
> [   17.704429]  net_rx_action+0x22f/0x280
> [   17.705706]  __do_softirq+0xfd/0x30a
> [   17.706921]  common_interrupt+0xa4/0xc0
> [   17.708206]  </IRQ>
> [   17.708922]  <TASK>
> [   17.709651]  asm_common_interrupt+0x1e/0x40
> [   17.711078] RIP: 0010:default_idle+0x18/0x20
>
> Signed-off-by: Hoang Le <hoa...@de...>
> ---
>   net/tipc/crypto.c | 8 ++++----
>   1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/net/tipc/crypto.c b/net/tipc/crypto.c
> index 81116312b753..9325479295b8 100644
> --- a/net/tipc/crypto.c
> +++ b/net/tipc/crypto.c
> @@ -524,7 +524,7 @@ static int tipc_aead_init(struct tipc_aead **aead, struct tipc_aead_key *ukey,
>   		return -EEXIST;
>   
>   	/* Allocate a new AEAD */
> -	tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
> +	tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
>   	if (unlikely(!tmp))
>   		return -ENOMEM;
>   
> @@ -1463,7 +1463,7 @@ int tipc_crypto_start(struct tipc_crypto **crypto, struct net *net,
>   		return -EEXIST;
>   
>   	/* Allocate crypto */
> -	c = kzalloc(sizeof(*c), GFP_KERNEL);
> +	c = kzalloc(sizeof(*c), GFP_ATOMIC);
>   	if (!c)
>   		return -ENOMEM;
>   
> @@ -1477,7 +1477,7 @@ int tipc_crypto_start(struct tipc_crypto **crypto, struct net *net,
>   	}
>   
>   	/* Allocate statistic structure */
> -	c->stats = alloc_percpu(struct tipc_crypto_stats);
> +	c->stats = alloc_percpu_gfp(struct tipc_crypto_stats, GFP_ATOMIC);
>   	if (!c->stats) {
>   		if (c->wq)
>   			destroy_workqueue(c->wq);
> @@ -2450,7 +2450,7 @@ static void tipc_crypto_work_tx(struct work_struct *work)
>   	}
>   
>   	/* Lets duplicate it first */
> -	skey = kmemdup(aead->key, tipc_aead_key_size(aead->key), GFP_KERNEL);
> +	skey = kmemdup(aead->key, tipc_aead_key_size(aead->key), GFP_ATOMIC);
>   	rcu_read_unlock();
>   
>   	/* Now, generate new key, initiate & distribute it */
Acked-by: Jon Maloy <jm...@re...>