gen_stats.c: Duplicate xstats buffer for later use

[ Upstream commit 1c4cff0cf55011792125b6041bc4e9713e46240f ]

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: Ignacy Gawędzki <ignacy.gawedzki@green-communications.fr>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Ignacy Gawędzki 2015-02-13 14:47:05 -08:00 committed by Greg Kroah-Hartman
parent 140b057ced
commit 54c7f8978b
1 changed files with 14 additions and 1 deletions

View File

@ -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;
}
@ -205,7 +208,9 @@ 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;
}
@ -213,6 +218,11 @@ 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);
@ -245,6 +255,9 @@ 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;
}