Commit fd2f4737 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

net: use u64_stats_t in struct pcpu_lstats 



In order to fix the data-race found by KCSAN, we
can use the new u64_stats_t type and its accessors instead
of plain u64 fields. This will still generate optimal code
for both 32 and 64 bit platforms.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 5260dd3e

drivers/net/loopback.c

+2 −2
Original line number Diff line number Diff line
@@ -106,8 +106,8 @@ void dev_lstats_read(struct net_device *dev, u64 *packets, u64 *bytes) 
		lb_stats = per_cpu_ptr(dev->lstats, i);

		do {

			start = u64_stats_fetch_begin_irq(&lb_stats->syncp);

			tpackets = lb_stats->packets;

			tbytes = lb_stats->bytes;

			tpackets = u64_stats_read(&lb_stats->packets);

			tbytes = u64_stats_read(&lb_stats->bytes);

		} while (u64_stats_fetch_retry_irq(&lb_stats->syncp, start));

		*bytes   += tbytes;

		*packets += tpackets;

include/linux/netdevice.h

+4 −4
Original line number Diff line number Diff line
@@ -2396,8 +2396,8 @@ struct pcpu_sw_netstats { 
} __aligned(4 * sizeof(u64));



struct pcpu_lstats {

	u64 packets;

	u64 bytes;

	u64_stats_t packets;

	u64_stats_t bytes;

	struct u64_stats_sync syncp;

} __aligned(2 * sizeof(u64));
@@ -2408,8 +2408,8 @@ static inline void dev_lstats_add(struct net_device *dev, unsigned int len) 
	struct pcpu_lstats *lstats = this_cpu_ptr(dev->lstats);



	u64_stats_update_begin(&lstats->syncp);

	lstats->bytes += len;

	lstats->packets++;

	u64_stats_add(&lstats->bytes, len);

	u64_stats_inc(&lstats->packets);

	u64_stats_update_end(&lstats->syncp);

}

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