From 9b96309c5b0b9e466773c07a5bc8b7b68fcf010a Mon Sep 17 00:00:00 2001 From: Pravin B Shelar Date: Fri, 23 Aug 2013 12:44:55 -0700 Subject: genl: Fix genl dumpit() locking. In case of genl-family with parallel ops off, dumpif() callback is expected to run under genl_lock, But commit def3117493eafd9df (genl: Allow concurrent genl callbacks.) changed this behaviour where only first dumpit() op was called under genl-lock. For subsequent dump, only nlk->cb_lock was taken. Following patch fixes it by defining locked dumpit() and done() callback which takes care of genl-locking. CC: Jesse Gross CC: Johannes Berg Signed-off-by: Pravin B Shelar Signed-off-by: David S. Miller --- net/netlink/genetlink.c | 51 ++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 46 insertions(+), 5 deletions(-) diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c index 512718adb0d5..7e0f4d199ade 100644 --- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -544,6 +544,30 @@ void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, } EXPORT_SYMBOL(genlmsg_put); +static int genl_lock_dumpit(struct sk_buff *skb, struct netlink_callback *cb) +{ + struct genl_ops *ops = cb->data; + int rc; + + genl_lock(); + rc = ops->dumpit(skb, cb); + genl_unlock(); + return rc; +} + +static int genl_lock_done(struct netlink_callback *cb) +{ + struct genl_ops *ops = cb->data; + int rc = 0; + + if (ops->done) { + genl_lock(); + rc = ops->done(cb); + genl_unlock(); + } + return rc; +} + static int genl_family_rcv_msg(struct genl_family *family, struct sk_buff *skb, struct nlmsghdr *nlh) @@ -572,15 +596,32 @@ static int genl_family_rcv_msg(struct genl_family *family, return -EPERM; if ((nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP) { - struct netlink_dump_control c = { - .dump = ops->dumpit, - .done = ops->done, - }; + int rc; if (ops->dumpit == NULL) return -EOPNOTSUPP; - return netlink_dump_start(net->genl_sock, skb, nlh, &c); + if (!family->parallel_ops) { + struct netlink_dump_control c = { + .data = ops, + .dump = genl_lock_dumpit, + .done = genl_lock_done, + }; + + genl_unlock(); + rc = netlink_dump_start(net->genl_sock, skb, nlh, &c); + genl_lock(); + + } else { + struct netlink_dump_control c = { + .dump = ops->dumpit, + .done = ops->done, + }; + + rc = netlink_dump_start(net->genl_sock, skb, nlh, &c); + } + + return rc; } if (ops->doit == NULL) -- cgit v1.2.3