Commit 22d046a7 authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

net: add data-race annotations in softnet_seq_show() 



softnet_seq_show() reads several fields that might be updated
concurrently. Add READ_ONCE() and WRITE_ONCE() annotations.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarWillem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250407163602.170356-4-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 7b6f0a85

net/core/dev.c

+4 −2
Original line number Diff line number Diff line
@@ -4953,7 +4953,8 @@ static void rps_trigger_softirq(void *data) 
	struct softnet_data *sd = data;



	____napi_schedule(sd, &sd->backlog);

	sd->received_rps++;

	/* Pairs with READ_ONCE() in softnet_seq_show() */

	WRITE_ONCE(sd->received_rps, sd->received_rps + 1);

}



#endif /* CONFIG_RPS */
@@ -7523,7 +7524,8 @@ static __latent_entropy void net_rx_action(void) 
		 */

		if (unlikely(budget <= 0 ||

			     time_after_eq(jiffies, time_limit))) {

			sd->time_squeeze++;

			/* Pairs with READ_ONCE() in softnet_seq_show() */

			WRITE_ONCE(sd->time_squeeze, sd->time_squeeze + 1);

			break;

		}

	}

net/core/net-procfs.c

+3 −3
Original line number Diff line number Diff line
@@ -145,11 +145,11 @@ static int softnet_seq_show(struct seq_file *seq, void *v) 
	seq_printf(seq,

		   "%08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x "

		   "%08x %08x\n",

		   sd->processed, atomic_read(&sd->dropped),

		   sd->time_squeeze, 0,

		   READ_ONCE(sd->processed), atomic_read(&sd->dropped),

		   READ_ONCE(sd->time_squeeze), 0,

		   0, 0, 0, 0, /* was fastroute */

		   0,	/* was cpu_collision */

		   sd->received_rps, flow_limit_count,

		   READ_ONCE(sd->received_rps), flow_limit_count,

		   input_qlen + process_qlen, (int)seq->index,

		   input_qlen, process_qlen);

	return 0;