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Commit 1c4cff0c authored by Ignacy Gawędzki's avatar Ignacy Gawędzki Committed by David S. Miller
Browse files

gen_stats.c: Duplicate xstats buffer for later use 



The gnet_stats_copy_app() function gets called, more often than not, with its
second argument a pointer to an automatic variable in the caller's stack.
Therefore, to avoid copying garbage afterwards when calling
gnet_stats_finish_copy(), this data is better copied to a dynamically allocated
memory that gets freed after use.

[xiyou.wangcong@gmail.com: remove a useless kfree()]

Signed-off-by: default avatarIgnacy Gawędzki <ignacy.gawedzki@green-communications.fr>
Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 5c277007

net/core/gen_stats.c

+14 −1
Original line number Diff line number Diff line
@@ -32,6 +32,9 @@ gnet_stats_copy(struct gnet_dump *d, int type, void *buf, int size) 
	return 0;



nla_put_failure:

	kfree(d->xstats);

	d->xstats = NULL;

	d->xstats_len = 0;

	spin_unlock_bh(d->lock);

	return -1;

}
@@ -305,7 +308,9 @@ int 
gnet_stats_copy_app(struct gnet_dump *d, void *st, int len)

{

	if (d->compat_xstats) {

		d->xstats = st;

		d->xstats = kmemdup(st, len, GFP_ATOMIC);

		if (!d->xstats)

			goto err_out;

		d->xstats_len = len;

	}
@@ -313,6 +318,11 @@ gnet_stats_copy_app(struct gnet_dump *d, void *st, int len) 
		return gnet_stats_copy(d, TCA_STATS_APP, st, len);



	return 0;



err_out:

	d->xstats_len = 0;

	spin_unlock_bh(d->lock);

	return -1;

}

EXPORT_SYMBOL(gnet_stats_copy_app);
@@ -345,6 +355,9 @@ gnet_stats_finish_copy(struct gnet_dump *d) 
			return -1;

	}



	kfree(d->xstats);

	d->xstats = NULL;

	d->xstats_len = 0;

	spin_unlock_bh(d->lock);

	return 0;

}