lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <ZMKxx6sQgVdCE_JH@C02YVCJELVCG>
Date: Thu, 27 Jul 2023 14:04:55 -0400
From: Andy Gospodarek <andrew.gospodarek@...adcom.com>
To: Jakub Kicinski <kuba@...nel.org>
Cc: davem@...emloft.net, netdev@...r.kernel.org, edumazet@...gle.com,
	pabeni@...hat.com, michael.chan@...adcom.com
Subject: Re: [PATCH net] bnxt: don't handle XDP in netpoll

On Thu, Jul 27, 2023 at 10:05:05AM -0700, Jakub Kicinski wrote:
> Similarly to other recently fixed drivers make sure we don't
> try to access XDP or page pool APIs when NAPI budget is 0.
> NAPI budget of 0 may mean that we are in netpoll.
> 
> This may result in running software IRQs in hard IRQ context,
> leading to deadlocks or crashes.
> 
> Fixes: 322b87ca55f2 ("bnxt_en: add page_pool support")
> Signed-off-by: Jakub Kicinski <kuba@...nel.org>

Reviewed-by: Andy Gospodarek <gospo@...adcom.com>

> ---
> CC: michael.chan@...adcom.com
> CC: gospo@...adcom.com
> 
> Side note - having to plumb the "budget" everywhere really makes
> me wonder if we shouldn't have had those APIs accept a pointer
> to napi_struct instead :S

We could also consider adding budget to struct bnxt_napi.  I'm not sure that
would work in all cases, however.

I'm good if this goes in as-is and we make enhancements from this as a starting
point.

> ---
>  drivers/net/ethernet/broadcom/bnxt/bnxt.c     | 19 +++++++++++--------
>  drivers/net/ethernet/broadcom/bnxt/bnxt.h     |  2 +-
>  drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c |  6 +++++-
>  drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h |  3 ++-
>  4 files changed, 19 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
> index a3bbd13c070f..fe1d645c39d0 100644
> --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
> +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
> @@ -687,7 +687,8 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev)
>  	return NETDEV_TX_OK;
>  }
>  
> -static void bnxt_tx_int(struct bnxt *bp, struct bnxt_napi *bnapi, int nr_pkts)
> +static void bnxt_tx_int(struct bnxt *bp, struct bnxt_napi *bnapi, int nr_pkts,
> +			int budget)
>  {
>  	struct bnxt_tx_ring_info *txr = bnapi->tx_ring;
>  	struct netdev_queue *txq = netdev_get_tx_queue(bp->dev, txr->txq_index);
> @@ -2595,10 +2596,11 @@ static int __bnxt_poll_work(struct bnxt *bp, struct bnxt_cp_ring_info *cpr,
>  	return rx_pkts;
>  }
>  
> -static void __bnxt_poll_work_done(struct bnxt *bp, struct bnxt_napi *bnapi)
> +static void __bnxt_poll_work_done(struct bnxt *bp, struct bnxt_napi *bnapi,
> +				  int budget)
>  {
>  	if (bnapi->tx_pkts && !bnapi->tx_fault) {
> -		bnapi->tx_int(bp, bnapi, bnapi->tx_pkts);
> +		bnapi->tx_int(bp, bnapi, bnapi->tx_pkts, budget);
>  		bnapi->tx_pkts = 0;
>  	}
>  
> @@ -2629,7 +2631,7 @@ static int bnxt_poll_work(struct bnxt *bp, struct bnxt_cp_ring_info *cpr,
>  	 */
>  	bnxt_db_cq(bp, &cpr->cp_db, cpr->cp_raw_cons);
>  
> -	__bnxt_poll_work_done(bp, bnapi);
> +	__bnxt_poll_work_done(bp, bnapi, budget);
>  	return rx_pkts;
>  }
>  
> @@ -2760,7 +2762,7 @@ static int __bnxt_poll_cqs(struct bnxt *bp, struct bnxt_napi *bnapi, int budget)
>  }
>  
>  static void __bnxt_poll_cqs_done(struct bnxt *bp, struct bnxt_napi *bnapi,
> -				 u64 dbr_type)
> +				 u64 dbr_type, int budget)
>  {
>  	struct bnxt_cp_ring_info *cpr = &bnapi->cp_ring;
>  	int i;
> @@ -2776,7 +2778,7 @@ static void __bnxt_poll_cqs_done(struct bnxt *bp, struct bnxt_napi *bnapi,
>  			cpr2->had_work_done = 0;
>  		}
>  	}
> -	__bnxt_poll_work_done(bp, bnapi);
> +	__bnxt_poll_work_done(bp, bnapi, budget);
>  }
>  
>  static int bnxt_poll_p5(struct napi_struct *napi, int budget)
> @@ -2806,7 +2808,8 @@ static int bnxt_poll_p5(struct napi_struct *napi, int budget)
>  			if (cpr->has_more_work)
>  				break;
>  
> -			__bnxt_poll_cqs_done(bp, bnapi, DBR_TYPE_CQ_ARMALL);
> +			__bnxt_poll_cqs_done(bp, bnapi, DBR_TYPE_CQ_ARMALL,
> +					     budget);
>  			cpr->cp_raw_cons = raw_cons;
>  			if (napi_complete_done(napi, work_done))
>  				BNXT_DB_NQ_ARM_P5(&cpr->cp_db,
> @@ -2836,7 +2839,7 @@ static int bnxt_poll_p5(struct napi_struct *napi, int budget)
>  		}
>  		raw_cons = NEXT_RAW_CMP(raw_cons);
>  	}
> -	__bnxt_poll_cqs_done(bp, bnapi, DBR_TYPE_CQ);
> +	__bnxt_poll_cqs_done(bp, bnapi, DBR_TYPE_CQ, budget);
>  	if (raw_cons != cpr->cp_raw_cons) {
>  		cpr->cp_raw_cons = raw_cons;
>  		BNXT_DB_NQ_P5(&cpr->cp_db, raw_cons);
> diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
> index 9d16757e27fe..bd44a5701e5f 100644
> --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h
> +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
> @@ -1005,7 +1005,7 @@ struct bnxt_napi {
>  	struct bnxt_tx_ring_info	*tx_ring;
>  
>  	void			(*tx_int)(struct bnxt *, struct bnxt_napi *,
> -					  int);
> +					  int tx_pkts, int budget);
>  	int			tx_pkts;
>  	u8			events;
>  	u8			tx_fault:1;
> diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
> index 5b6fbdc4dc40..33b7eddfbf41 100644
> --- a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
> +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
> @@ -125,7 +125,8 @@ static void __bnxt_xmit_xdp_redirect(struct bnxt *bp,
>  	dma_unmap_len_set(tx_buf, len, 0);
>  }
>  
> -void bnxt_tx_int_xdp(struct bnxt *bp, struct bnxt_napi *bnapi, int nr_pkts)
> +void bnxt_tx_int_xdp(struct bnxt *bp, struct bnxt_napi *bnapi, int nr_pkts,
> +		     int budget)
>  {
>  	struct bnxt_tx_ring_info *txr = bnapi->tx_ring;
>  	struct bnxt_rx_ring_info *rxr = bnapi->rx_ring;
> @@ -135,6 +136,9 @@ void bnxt_tx_int_xdp(struct bnxt *bp, struct bnxt_napi *bnapi, int nr_pkts)
>  	u16 last_tx_cons = tx_cons;
>  	int i, j, frags;
>  
> +	if (!budget)
> +		return;
> +
>  	for (i = 0; i < nr_pkts; i++) {
>  		tx_buf = &txr->tx_buf_ring[tx_cons];
>  
> diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h
> index ea430d6961df..3ab47ae2f26d 100644
> --- a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h
> +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h
> @@ -16,7 +16,8 @@ struct bnxt_sw_tx_bd *bnxt_xmit_bd(struct bnxt *bp,
>  				   struct bnxt_tx_ring_info *txr,
>  				   dma_addr_t mapping, u32 len,
>  				   struct xdp_buff *xdp);
> -void bnxt_tx_int_xdp(struct bnxt *bp, struct bnxt_napi *bnapi, int nr_pkts);
> +void bnxt_tx_int_xdp(struct bnxt *bp, struct bnxt_napi *bnapi, int nr_pkts,
> +		     int budget);
>  bool bnxt_rx_xdp(struct bnxt *bp, struct bnxt_rx_ring_info *rxr, u16 cons,
>  		 struct xdp_buff xdp, struct page *page, u8 **data_ptr,
>  		 unsigned int *len, u8 *event);
> -- 
> 2.41.0
> 

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ