2012-09-26 04:52:46

by Gao feng

[permalink] [raw]
Subject: [PATCH 01/11] netlink: add reference of module in netlink_dump_start

I get a panic when I use ss -a and rmmod inet_diag at the
same time.

it's because netlink_dump use inet_diag_dump witch function
belongs to module inet_diag.

I search the codes and find many modules have the same problem.
We need add reference of the module witch the cb->dump belongs
to.

since CONFIG_NET is bool,so netlink_dump_start in rtnetlink.c
and genetlink.c will never trigger this problem.

Thanks for all help from Stephen,Jan and Eric.

Signed-off-by: Gao feng <[email protected]>
---
include/linux/netlink.h | 4 ++++
net/netlink/af_netlink.c | 25 +++++++++++++++++++++----
2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index f74dd13..a3641e3 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -232,6 +232,8 @@ struct netlink_callback {
struct netlink_callback *cb);
int (*done)(struct netlink_callback *cb);
void *data;
+ /* the module that dump function belong to */
+ struct module *module;
u16 family;
u16 min_dump_alloc;
unsigned int prev_seq, seq;
@@ -251,9 +253,11 @@ struct netlink_dump_control {
int (*dump)(struct sk_buff *skb, struct netlink_callback *);
int (*done)(struct netlink_callback*);
void *data;
+ struct module *module;
u16 min_dump_alloc;
};

+extern int netlink_dump_done(struct netlink_callback *cb);
extern int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
const struct nlmsghdr *nlh,
struct netlink_dump_control *control);
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 5270238..011091c 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1769,6 +1769,14 @@ errout_skb:
return err;
}

+int netlink_dump_done(struct netlink_callback *cb)
+{
+ if (cb->module)
+ module_put(cb->module);
+ return 0;
+}
+EXPORT_SYMBOL(netlink_dump_done);
+
int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
const struct nlmsghdr *nlh,
struct netlink_dump_control *control)
@@ -1786,6 +1794,7 @@ int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
cb->done = control->done;
cb->nlh = nlh;
cb->data = control->data;
+ cb->module = control->module;
cb->min_dump_alloc = control->min_dump_alloc;
atomic_inc(&skb->users);
cb->skb = skb;
@@ -1796,19 +1805,27 @@ int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
return -ECONNREFUSED;
}
nlk = nlk_sk(sk);
- /* A dump is in progress... */
+
mutex_lock(nlk->cb_mutex);
+ /* A dump is in progress... */
if (nlk->cb) {
mutex_unlock(nlk->cb_mutex);
netlink_destroy_callback(cb);
- sock_put(sk);
- return -EBUSY;
+ ret = -EBUSY;
+ goto out;
+ }
+ /* add reference of module witch cb->dump belone to */
+ if (cb->module && !try_module_get(cb->module)) {
+ mutex_unlock(nlk->cb_mutex);
+ ret = -EPROTONOSUPPORT;
+ goto out;
}
+
nlk->cb = cb;
mutex_unlock(nlk->cb_mutex);

ret = netlink_dump(sk);
-
+out:
sock_put(sk);

if (ret)
--
1.7.7.6


2012-09-26 04:52:45

by Gao feng

[permalink] [raw]
Subject: [PATCH 03/11] unix_diag: pass unix_diag module to netlink_dump_start

use proper netlink_dump_control.done and .module to avoid panic.

Signed-off-by: Gao feng <[email protected]>
---
net/unix/diag.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/net/unix/diag.c b/net/unix/diag.c
index 750b134..5e09553 100644
--- a/net/unix/diag.c
+++ b/net/unix/diag.c
@@ -299,6 +299,8 @@ static int unix_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h)
if (h->nlmsg_flags & NLM_F_DUMP) {
struct netlink_dump_control c = {
.dump = unix_diag_dump,
+ .done = netlink_dump_done,
+ .module = THIS_MODULE,
};
return netlink_dump_start(net->diag_nlsk, skb, h, &c);
} else
--
1.7.7.6

2012-09-26 04:52:11

by Gao feng

[permalink] [raw]
Subject: [PATCH 02/11] inet_diag: pass inet_diag module to netlink_dump_start

use proper netlink_dump_control.done and .module to avoid panic.

Signed-off-by: Gao feng <[email protected]>
---
net/ipv4/inet_diag.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index 570e61f..36d4be5 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -972,6 +972,8 @@ static int inet_diag_rcv_msg_compat(struct sk_buff *skb, struct nlmsghdr *nlh)
{
struct netlink_dump_control c = {
.dump = inet_diag_dump_compat,
+ .done = netlink_dump_done,
+ .module = THIS_MODULE,
};
return netlink_dump_start(net->diag_nlsk, skb, nlh, &c);
}
@@ -1001,6 +1003,8 @@ static int inet_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h)
{
struct netlink_dump_control c = {
.dump = inet_diag_dump,
+ .done = netlink_dump_done,
+ .module = THIS_MODULE,
};
return netlink_dump_start(net->diag_nlsk, skb, h, &c);
}
--
1.7.7.6


2012-09-26 04:52:16

by Gao feng

[permalink] [raw]
Subject: [PATCH 07/11] nfnetlink_cttimeout: pass nfnetlink_cttimeout module to netlink_dump_start

use proper netlink_dump_control.done and .module to avoid panic.

Signed-off-by: Gao feng <[email protected]>
---
net/netfilter/nfnetlink_cttimeout.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/net/netfilter/nfnetlink_cttimeout.c b/net/netfilter/nfnetlink_cttimeout.c
index cdecbc8..bc3e730 100644
--- a/net/netfilter/nfnetlink_cttimeout.c
+++ b/net/netfilter/nfnetlink_cttimeout.c
@@ -248,6 +248,8 @@ cttimeout_get_timeout(struct sock *ctnl, struct sk_buff *skb,
if (nlh->nlmsg_flags & NLM_F_DUMP) {
struct netlink_dump_control c = {
.dump = ctnl_timeout_dump,
+ .done = netlink_dump_done,
+ .module = THIS_MODULE,
};
return netlink_dump_start(ctnl, skb, nlh, &c);
}
--
1.7.7.6


2012-09-26 04:52:17

by Gao feng

[permalink] [raw]
Subject: [PATCH 08/11] crypto: pass crypto_user module to netlink_dump_start

use proper netlink_dump_control.done and .module to avoid panic.

Signed-off-by: Gao feng <[email protected]>
Cc: Herbert Xu <[email protected]>
---
crypto/crypto_user.c | 6 +++++-
1 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/crypto/crypto_user.c b/crypto/crypto_user.c
index ba2c611..b5cb32b 100644
--- a/crypto/crypto_user.c
+++ b/crypto/crypto_user.c
@@ -249,6 +249,7 @@ out_err:

static int crypto_dump_report_done(struct netlink_callback *cb)
{
+ netlink_dump_done(cb);
return 0;
}

@@ -430,13 +431,15 @@ static struct crypto_link {
int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **);
int (*dump)(struct sk_buff *, struct netlink_callback *);
int (*done)(struct netlink_callback *);
+ struct module *module;
} crypto_dispatch[CRYPTO_NR_MSGTYPES] = {
[CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = { .doit = crypto_add_alg},
[CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = { .doit = crypto_del_alg},
[CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = { .doit = crypto_update_alg},
[CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = { .doit = crypto_report,
.dump = crypto_dump_report,
- .done = crypto_dump_report_done},
+ .done = crypto_dump_report_done,
+ .module = THIS_MODULE},
};

static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
@@ -470,6 +473,7 @@ static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
struct netlink_dump_control c = {
.dump = link->dump,
.done = link->done,
+ .module = link->module,
.min_dump_alloc = dump_alloc,
};
return netlink_dump_start(crypto_nlsk, skb, nlh, &c);
--
1.7.7.6

2012-09-26 04:52:18

by Gao feng

[permalink] [raw]
Subject: [PATCH 09/11] xfrm: pass xfrm_user module to netlink_dump_start

use proper netlink_dump_control.done and .module to avoid panic.

Signed-off-by: Gao feng <[email protected]>
---
net/xfrm/xfrm_user.c | 10 ++++++++--
1 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 289f4bf..fb6b06b 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -867,6 +867,7 @@ static int xfrm_dump_sa_done(struct netlink_callback *cb)
{
struct xfrm_state_walk *walk = (struct xfrm_state_walk *) &cb->args[1];
xfrm_state_walk_done(walk);
+ netlink_dump_done(cb);
return 0;
}

@@ -1538,6 +1539,7 @@ static int xfrm_dump_policy_done(struct netlink_callback *cb)
struct xfrm_policy_walk *walk = (struct xfrm_policy_walk *) &cb->args[1];

xfrm_policy_walk_done(walk);
+ netlink_dump_done(cb);
return 0;
}

@@ -2308,17 +2310,20 @@ static struct xfrm_link {
int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **);
int (*dump)(struct sk_buff *, struct netlink_callback *);
int (*done)(struct netlink_callback *);
+ struct module *module;
} xfrm_dispatch[XFRM_NR_MSGTYPES] = {
[XFRM_MSG_NEWSA - XFRM_MSG_BASE] = { .doit = xfrm_add_sa },
[XFRM_MSG_DELSA - XFRM_MSG_BASE] = { .doit = xfrm_del_sa },
[XFRM_MSG_GETSA - XFRM_MSG_BASE] = { .doit = xfrm_get_sa,
.dump = xfrm_dump_sa,
- .done = xfrm_dump_sa_done },
+ .done = xfrm_dump_sa_done,
+ .module = THIS_MODULE },
[XFRM_MSG_NEWPOLICY - XFRM_MSG_BASE] = { .doit = xfrm_add_policy },
[XFRM_MSG_DELPOLICY - XFRM_MSG_BASE] = { .doit = xfrm_get_policy },
[XFRM_MSG_GETPOLICY - XFRM_MSG_BASE] = { .doit = xfrm_get_policy,
.dump = xfrm_dump_policy,
- .done = xfrm_dump_policy_done },
+ .done = xfrm_dump_policy_done,
+ .module = THIS_MODULE },
[XFRM_MSG_ALLOCSPI - XFRM_MSG_BASE] = { .doit = xfrm_alloc_userspi },
[XFRM_MSG_ACQUIRE - XFRM_MSG_BASE] = { .doit = xfrm_add_acquire },
[XFRM_MSG_EXPIRE - XFRM_MSG_BASE] = { .doit = xfrm_add_sa_expire },
@@ -2362,6 +2367,7 @@ static int xfrm_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
struct netlink_dump_control c = {
.dump = link->dump,
.done = link->done,
+ .module = link->module,
};
return netlink_dump_start(net->xfrm.nlsk, skb, nlh, &c);
}
--
1.7.7.6

2012-09-26 04:52:20

by Gao feng

[permalink] [raw]
Subject: [PATCH 11/11] infiniband: pass rdma_cm module to netlink_dump_start

use proper netlink_dump_control.done and .module to avoid panic.

Signed-off-by: Gao feng <[email protected]>
Cc: Roland Dreier <[email protected]org>
Cc: Sean Hefty <[email protected]>
---
drivers/infiniband/core/cma.c | 3 ++-
drivers/infiniband/core/netlink.c | 2 ++
include/rdma/rdma_netlink.h | 1 +
3 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index 7172559..d1febf0 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -3495,7 +3495,8 @@ out:
}

static const struct ibnl_client_cbs cma_cb_table[] = {
- [RDMA_NL_RDMA_CM_ID_STATS] = { .dump = cma_get_id_stats },
+ [RDMA_NL_RDMA_CM_ID_STATS] = { .dump = cma_get_id_stats,
+ .module = THIS_MODULE },
};

static int __init cma_init(void)
diff --git a/drivers/infiniband/core/netlink.c b/drivers/infiniband/core/netlink.c
index 3ae2bfd..1468827 100644
--- a/drivers/infiniband/core/netlink.c
+++ b/drivers/infiniband/core/netlink.c
@@ -154,6 +154,8 @@ static int ibnl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
{
struct netlink_dump_control c = {
.dump = client->cb_table[op].dump,
+ .done = netlink_dump_done,
+ .module = client->cb_table[op].module,
};
return netlink_dump_start(nls, skb, nlh, &c);
}
diff --git a/include/rdma/rdma_netlink.h b/include/rdma/rdma_netlink.h
index 3c5363a..bd3d8b2 100644
--- a/include/rdma/rdma_netlink.h
+++ b/include/rdma/rdma_netlink.h
@@ -39,6 +39,7 @@ struct rdma_cm_id_stats {

struct ibnl_client_cbs {
int (*dump)(struct sk_buff *skb, struct netlink_callback *nlcb);
+ struct module *module;
};

int ibnl_init(void);
--
1.7.7.6

2012-09-26 04:52:15

by Gao feng

[permalink] [raw]
Subject: [PATCH 06/11] nfnetlink_cthelper: pass nfnetlink_cthelper module to netlink_dump_start

use proper netlink_dump_control.done and .module to avoid panic.

Signed-off-by: Gao feng <[email protected]>
---
net/netfilter/nfnetlink_cthelper.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/net/netfilter/nfnetlink_cthelper.c b/net/netfilter/nfnetlink_cthelper.c
index d683619..117343f 100644
--- a/net/netfilter/nfnetlink_cthelper.c
+++ b/net/netfilter/nfnetlink_cthelper.c
@@ -501,6 +501,8 @@ nfnl_cthelper_get(struct sock *nfnl, struct sk_buff *skb,
if (nlh->nlmsg_flags & NLM_F_DUMP) {
struct netlink_dump_control c = {
.dump = nfnl_cthelper_dump_table,
+ .done = netlink_dump_done,
+ .module = THIS_MODULE,
};
return netlink_dump_start(nfnl, skb, nlh, &c);
}
--
1.7.7.6

2012-09-26 04:52:13

by Gao feng

[permalink] [raw]
Subject: [PATCH 04/11] nf_conntrack_netlink: pass nf_conntrack_netlink module to netlink_dump_start

use proper netlink_dump_control.done and .module to avoid panic.

Signed-off-by: Gao feng <[email protected]>
---
net/netfilter/nf_conntrack_netlink.c | 8 ++++++++
1 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 9807f32..509a257 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -706,6 +706,7 @@ static int ctnetlink_done(struct netlink_callback *cb)
nf_ct_put((struct nf_conn *)cb->args[1]);
if (cb->data)
kfree(cb->data);
+ netlink_dump_done(cb);
return 0;
}

@@ -1022,6 +1023,7 @@ ctnetlink_get_conntrack(struct sock *ctnl, struct sk_buff *skb,
struct netlink_dump_control c = {
.dump = ctnetlink_dump_table,
.done = ctnetlink_done,
+ .module = THIS_MODULE,
};
#ifdef CONFIG_NF_CONNTRACK_MARK
if (cda[CTA_MARK] && cda[CTA_MARK_MASK]) {
@@ -1706,6 +1708,8 @@ ctnetlink_stat_ct_cpu(struct sock *ctnl, struct sk_buff *skb,
if (nlh->nlmsg_flags & NLM_F_DUMP) {
struct netlink_dump_control c = {
.dump = ctnetlink_ct_stat_cpu_dump,
+ .done = netlink_dump_done,
+ .module = THIS_MODULE,
};
return netlink_dump_start(ctnl, skb, nlh, &c);
}
@@ -2141,6 +2145,7 @@ static int ctnetlink_exp_done(struct netlink_callback *cb)
{
if (cb->args[1])
nf_ct_expect_put((struct nf_conntrack_expect *)cb->args[1]);
+ netlink_dump_done(cb);
return 0;
}

@@ -2222,6 +2227,7 @@ ctnetlink_get_expect(struct sock *ctnl, struct sk_buff *skb,
struct netlink_dump_control c = {
.dump = ctnetlink_exp_dump_table,
.done = ctnetlink_exp_done,
+ .module = THIS_MODULE,
};
return netlink_dump_start(ctnl, skb, nlh, &c);
}
@@ -2660,6 +2666,8 @@ ctnetlink_stat_exp_cpu(struct sock *ctnl, struct sk_buff *skb,
if (nlh->nlmsg_flags & NLM_F_DUMP) {
struct netlink_dump_control c = {
.dump = ctnetlink_exp_stat_cpu_dump,
+ .done = netlink_dump_done,
+ .module = THIS_MODULE,
};
return netlink_dump_start(ctnl, skb, nlh, &c);
}
--
1.7.7.6

2012-09-26 04:52:14

by Gao feng

[permalink] [raw]
Subject: [PATCH 05/11] nfnetlink_acct: pass nfnetlink_acct module to netlink_dump_start

use proper netlink_dump_control.done and .module to avoid panic.

Signed-off-by: Gao feng <[email protected]>
---
net/netfilter/nfnetlink_acct.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/net/netfilter/nfnetlink_acct.c b/net/netfilter/nfnetlink_acct.c
index b2e7310..1e9cb0f 100644
--- a/net/netfilter/nfnetlink_acct.c
+++ b/net/netfilter/nfnetlink_acct.c
@@ -175,6 +175,8 @@ nfnl_acct_get(struct sock *nfnl, struct sk_buff *skb,
if (nlh->nlmsg_flags & NLM_F_DUMP) {
struct netlink_dump_control c = {
.dump = nfnl_acct_dump,
+ .done = netlink_dump_done,
+ .module = THIS_MODULE,
};
return netlink_dump_start(nfnl, skb, nlh, &c);
}
--
1.7.7.6

2012-09-26 05:41:03

by Steffen Klassert

[permalink] [raw]
Subject: Re: [PATCH 01/11] netlink: add reference of module in netlink_dump_start

On Wed, Sep 26, 2012 at 12:52:10PM +0800, Gao feng wrote:
> +
> int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
> const struct nlmsghdr *nlh,
> struct netlink_dump_control *control)
> @@ -1786,6 +1794,7 @@ int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
> cb->done = control->done;
> cb->nlh = nlh;
> cb->data = control->data;
> + cb->module = control->module;
> cb->min_dump_alloc = control->min_dump_alloc;
> atomic_inc(&skb->users);
> cb->skb = skb;
> @@ -1796,19 +1805,27 @@ int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
> return -ECONNREFUSED;
> }
> nlk = nlk_sk(sk);
> - /* A dump is in progress... */
> +
> mutex_lock(nlk->cb_mutex);
> + /* A dump is in progress... */
> if (nlk->cb) {
> mutex_unlock(nlk->cb_mutex);
> netlink_destroy_callback(cb);
> - sock_put(sk);
> - return -EBUSY;
> + ret = -EBUSY;
> + goto out;
> + }
> + /* add reference of module witch cb->dump belone to */
> + if (cb->module && !try_module_get(cb->module)) {
> + mutex_unlock(nlk->cb_mutex);
> + ret = -EPROTONOSUPPORT;
> + goto out;

Looks like you leak the allocated netlink_callback here.
You should call netlink_destroy_callback() before you exit.

> }
> +
> nlk->cb = cb;
> mutex_unlock(nlk->cb_mutex);
>
> ret = netlink_dump(sk);
> -
> +out:
> sock_put(sk);
>
> if (ret)
> --

2012-09-26 05:49:45

by Steffen Klassert

[permalink] [raw]
Subject: Re: [PATCH 08/11] crypto: pass crypto_user module to netlink_dump_start

On Wed, Sep 26, 2012 at 12:52:17PM +0800, Gao feng wrote:
> use proper netlink_dump_control.done and .module to avoid panic.
>
> Signed-off-by: Gao feng <[email protected]>
> Cc: Herbert Xu <[email protected]>
> ---
> crypto/crypto_user.c | 6 +++++-
> 1 files changed, 5 insertions(+), 1 deletions(-)
>
> diff --git a/crypto/crypto_user.c b/crypto/crypto_user.c
> index ba2c611..b5cb32b 100644
> --- a/crypto/crypto_user.c
> +++ b/crypto/crypto_user.c
> @@ -249,6 +249,7 @@ out_err:
>
> static int crypto_dump_report_done(struct netlink_callback *cb)
> {
> + netlink_dump_done(cb);
> return 0;

It's probaply better to return the return value of netlink_dump_done()
instead. Right now, netlink_dump_done() returns 0 in any case,
but this might change over time.

2012-09-26 06:05:58

by Gao feng

[permalink] [raw]
Subject: Re: [PATCH 01/11] netlink: add reference of module in netlink_dump_start

于 2012年09月26日 13:41, Steffen Klassert 写道:
> On Wed, Sep 26, 2012 at 12:52:10PM +0800, Gao feng wrote:
>> +
>> int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
>> const struct nlmsghdr *nlh,
>> struct netlink_dump_control *control)
>> @@ -1786,6 +1794,7 @@ int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
>> cb->done = control->done;
>> cb->nlh = nlh;
>> cb->data = control->data;
>> + cb->module = control->module;
>> cb->min_dump_alloc = control->min_dump_alloc;
>> atomic_inc(&skb->users);
>> cb->skb = skb;
>> @@ -1796,19 +1805,27 @@ int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
>> return -ECONNREFUSED;
>> }
>> nlk = nlk_sk(sk);
>> - /* A dump is in progress... */
>> +
>> mutex_lock(nlk->cb_mutex);
>> + /* A dump is in progress... */
>> if (nlk->cb) {
>> mutex_unlock(nlk->cb_mutex);
>> netlink_destroy_callback(cb);
>> - sock_put(sk);
>> - return -EBUSY;
>> + ret = -EBUSY;
>> + goto out;
>> + }
>> + /* add reference of module witch cb->dump belone to */
>> + if (cb->module && !try_module_get(cb->module)) {
>> + mutex_unlock(nlk->cb_mutex);
>> + ret = -EPROTONOSUPPORT;
>> + goto out;
>
> Looks like you leak the allocated netlink_callback here.
> You should call netlink_destroy_callback() before you exit.
>

oops, I will fix it,thanks very much!

2012-09-26 07:07:27

by Eric Dumazet

[permalink] [raw]
Subject: Re: [PATCH 01/11] netlink: add reference of module in netlink_dump_start

On Wed, 2012-09-26 at 12:52 +0800, Gao feng wrote:

> +int netlink_dump_done(struct netlink_callback *cb)
> +{
> + if (cb->module)
> + module_put(cb->module);
> + return 0;
> +}
> +EXPORT_SYMBOL(netlink_dump_done);
> +

No need to test cb->module being not NULL


int netlink_dump_done(struct netlink_callback *cb)
{
module_put(cb->module);
return 0;
}

Same remark for try_module_get() call

2012-09-26 07:21:54

by Gao feng

[permalink] [raw]
Subject: Re: [PATCH 08/11] crypto: pass crypto_user module to netlink_dump_start

于 2012年09月26日 13:49, Steffen Klassert 写道:
> On Wed, Sep 26, 2012 at 12:52:17PM +0800, Gao feng wrote:
>> use proper netlink_dump_control.done and .module to avoid panic.
>>
>> Signed-off-by: Gao feng <[email protected]>
>> Cc: Herbert Xu <[email protected]>
>> ---
>> crypto/crypto_user.c | 6 +++++-
>> 1 files changed, 5 insertions(+), 1 deletions(-)
>>
>> diff --git a/crypto/crypto_user.c b/crypto/crypto_user.c
>> index ba2c611..b5cb32b 100644
>> --- a/crypto/crypto_user.c
>> +++ b/crypto/crypto_user.c
>> @@ -249,6 +249,7 @@ out_err:
>>
>> static int crypto_dump_report_done(struct netlink_callback *cb)
>> {
>> + netlink_dump_done(cb);
>> return 0;
>
> It's probaply better to return the return value of netlink_dump_done()
> instead. Right now, netlink_dump_done() returns 0 in any case,
> but this might change over time.
>

Get it, will fix, thanks!

2012-09-26 07:24:03

by Gao feng

[permalink] [raw]
Subject: Re: [PATCH 01/11] netlink: add reference of module in netlink_dump_start

于 2012年09月26日 15:07, Eric Dumazet 写道:
> On Wed, 2012-09-26 at 12:52 +0800, Gao feng wrote:
>
>> +int netlink_dump_done(struct netlink_callback *cb)
>> +{
>> + if (cb->module)
>> + module_put(cb->module);
>> + return 0;
>> +}
>> +EXPORT_SYMBOL(netlink_dump_done);
>> +
>
> No need to test cb->module being not NULL
>
>
> int netlink_dump_done(struct netlink_callback *cb)
> {
> module_put(cb->module);
> return 0;
> }
>
> Same remark for try_module_get() call
>

will fix it in v2 patchset.

thanks Eric.

2012-09-26 16:07:48

by Stephen Hemminger

[permalink] [raw]
Subject: Re: [PATCH 02/11] inet_diag: pass inet_diag module to netlink_dump_start

On Wed, 26 Sep 2012 12:52:11 +0800
Gao feng <[email protected]> wrote:

> struct netlink_dump_control c = {
> .dump = inet_diag_dump_compat,
> + .done = netlink_dump_done,
> + .module = THIS_MODULE,
> };

Since these are immutable, why the netlink_dump_control structures
on the stack (which requires code to generate at runtime), and instead
make them global

static const struct netlink_dump_control unix_diag_ctrl = {
...

2012-09-26 17:26:14

by Pablo Neira Ayuso

[permalink] [raw]
Subject: Re: [PATCH 02/11] inet_diag: pass inet_diag module to netlink_dump_start

On Wed, Sep 26, 2012 at 09:07:14AM -0700, Stephen Hemminger wrote:
> On Wed, 26 Sep 2012 12:52:11 +0800
> Gao feng <[email protected]> wrote:
>
> > struct netlink_dump_control c = {
> > .dump = inet_diag_dump_compat,
> > + .done = netlink_dump_done,
> > + .module = THIS_MODULE,
> > };
>
> Since these are immutable, why the netlink_dump_control structures
> on the stack (which requires code to generate at runtime), and instead
> make them global
>
> static const struct netlink_dump_control unix_diag_ctrl = {
> ...

I made that code. I can send a patch to statify those
netlink_dump_control structures.