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| author | Ignacy Gawędzki <ignacy.gawedzki@green-communications.fr> | 2015-02-13 14:47:05 -0800 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2015-05-09 23:16:37 +0100 |
| commit | 24aa85b0d9ef3f2cd3d99be59bbf58fba269ba08 (patch) | |
| tree | 6b77a3142bc46cf68b870011cebc8a4000859a81 /net | |
| parent | c9f412a4c739cb7eb2b6af845f97539d8d1fcf44 (diff) | |
| download | lwn-24aa85b0d9ef3f2cd3d99be59bbf58fba269ba08.tar.gz lwn-24aa85b0d9ef3f2cd3d99be59bbf58fba269ba08.zip | |
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: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/gen_stats.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/net/core/gen_stats.c b/net/core/gen_stats.c index 0452eb27a272..91080c190c33 100644 --- a/net/core/gen_stats.c +++ b/net/core/gen_stats.c @@ -31,6 +31,9 @@ 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; } @@ -204,7 +207,9 @@ 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; } @@ -212,6 +217,11 @@ 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); @@ -244,6 +254,9 @@ 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; } |