* [can-next] can: proc: remove pointers from CAN specific proc output
@ 2026-08-14 10:54 Oliver Hartkopp
2026-08-14 12:31 ` Sebastian Andrzej Siewior
0 siblings, 1 reply; 5+ messages in thread
From: Oliver Hartkopp @ 2026-08-14 10:54 UTC (permalink / raw)
To: linux-can; +Cc: netdev, Oliver Hartkopp, Sebastian Andrzej Siewior
The proc content in /proc/net/can/ and /proc/net/can-bcm/ is intended to
check the internal filter lists (af_can, can_raw) and the efficiency and
functionality of can_bcm jobs. While it was ok to leak kernel internal
addresses at time of writing the times have changed and multiple attempts
have been taken to hash or remove such now sensible data.
This patch removes the disclosure of pointers and instead provides the
function names and sock inode numbers when available. As there's no known
tooling around the CAN specific proc output breaking the ABI with this
rework creates no issue.
Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
---
Documentation/networking/can.rst | 14 +++++++-------
include/linux/can/core.h | 2 +-
net/can/af_can.c | 6 +++---
net/can/af_can.h | 2 +-
net/can/bcm.c | 13 ++++++-------
net/can/gw.c | 2 +-
net/can/isotp.c | 4 ++--
net/can/j1939/main.c | 2 +-
net/can/proc.c | 27 ++++++++++++++++-----------
net/can/raw.c | 4 ++--
10 files changed, 40 insertions(+), 36 deletions(-)
diff --git a/Documentation/networking/can.rst b/Documentation/networking/can.rst
index 536ff411da1d..7bdb27a22a0e 100644
--- a/Documentation/networking/can.rst
+++ b/Documentation/networking/can.rst
@@ -1040,19 +1040,19 @@ As described in :ref:`socketcan-receive-lists` the SocketCAN core uses several f
lists to deliver received CAN frames to CAN protocol modules. These
receive lists, their filters and the count of filter matches can be
checked in the appropriate receive list. All entries contain the
device and a protocol module identifier::
- foo@bar:~$ cat /proc/net/can/rcvlist_all
+ foo@bar:~$ cat /proc/net/can/rcvlist_fil
- receive list 'rx_all':
- (vcan3: no entry)
- (vcan2: no entry)
- (vcan1: no entry)
- device can_id can_mask function userdata matches ident
- vcan0 000 00000000 f88e6370 f6c6f400 0 raw
+ receive list 'rx_fil':
(any: no entry)
+ device can_id can_mask matches sock_inode function
+ vcan0 80000123 c00007ff 0 000000000000f862 raw_rcv [can_raw]
+ (vcan1: no entry)
+ (vcan2: no entry)
+ (vcan3: no entry)
In this example an application requests any CAN traffic from vcan0::
rcvlist_all - list for unfiltered entries (no filter operations)
rcvlist_eff - list for single extended frame (EFF) entries
diff --git a/include/linux/can/core.h b/include/linux/can/core.h
index 3287232e3cad..c7ad1d36b657 100644
--- a/include/linux/can/core.h
+++ b/include/linux/can/core.h
@@ -48,11 +48,11 @@ extern int can_proto_register(const struct can_proto *cp);
extern void can_proto_unregister(const struct can_proto *cp);
int can_rx_register(struct net *net, struct net_device *dev,
canid_t can_id, canid_t mask,
void (*func)(struct sk_buff *, void *),
- void *data, char *ident, struct sock *sk);
+ void *data, u64 ino, struct sock *sk);
extern void can_rx_unregister(struct net *net, struct net_device *dev,
canid_t can_id, canid_t mask,
void (*func)(struct sk_buff *, void *),
void *data);
diff --git a/net/can/af_can.c b/net/can/af_can.c
index 7bc86b176b4d..be0661679ef8 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -416,11 +416,11 @@ static struct hlist_head *can_rcv_list_find(canid_t *can_id, canid_t *mask,
* @dev: pointer to netdevice (NULL => subscribe from 'all' CAN devices list)
* @can_id: CAN identifier (see description)
* @mask: CAN mask (see description)
* @func: callback function on filter match
* @data: returned parameter for callback function
- * @ident: string for calling module identification
+ * @ino: inode number of sock (0 = unknown)
* @sk: socket pointer (might be NULL)
*
* Description:
* Invokes the callback function with the received sk_buff and the given
* parameter 'data' on a matching receive filter. A filter matches, when
@@ -441,11 +441,11 @@ static struct hlist_head *can_rcv_list_find(canid_t *can_id, canid_t *mask,
* -ENOMEM on missing cache mem to create subscription entry
* -ENODEV unknown device
*/
int can_rx_register(struct net *net, struct net_device *dev, canid_t can_id,
canid_t mask, void (*func)(struct sk_buff *, void *),
- void *data, char *ident, struct sock *sk)
+ void *data, u64 ino, struct sock *sk)
{
struct receiver *rcv;
struct hlist_head *rcv_list;
struct can_dev_rcv_lists *dev_rcv_lists;
struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;
@@ -470,11 +470,11 @@ int can_rx_register(struct net *net, struct net_device *dev, canid_t can_id,
rcv->can_id = can_id;
rcv->mask = mask;
atomic_long_set(&rcv->matches, 0);
rcv->func = func;
rcv->data = data;
- rcv->ident = ident;
+ rcv->ino = ino;
rcv->sk = sk;
hlist_add_head_rcu(&rcv->list, rcv_list);
dev_rcv_lists->entries++;
diff --git a/net/can/af_can.h b/net/can/af_can.h
index 87887014f562..6e593ed5db5f 100644
--- a/net/can/af_can.h
+++ b/net/can/af_can.h
@@ -53,11 +53,11 @@ struct receiver {
canid_t can_id;
canid_t mask;
atomic_long_t matches;
void (*func)(struct sk_buff *skb, void *data);
void *data;
- char *ident;
+ u64 ino;
struct sock *sk;
struct rcu_head rcu;
};
/* statistic structures */
diff --git a/net/can/bcm.c b/net/can/bcm.c
index 3d637a1e0ac1..90b22326c8e1 100644
--- a/net/can/bcm.c
+++ b/net/can/bcm.c
@@ -141,11 +141,11 @@ struct bcm_sock {
struct list_head notifier;
struct list_head rx_ops;
struct list_head tx_ops;
unsigned long dropped_usr_msgs;
struct proc_dir_entry *bcm_proc_read;
- char procname [32]; /* inode number in decimal with \0 */
+ char procname [18]; /* inode number in hex with \0 */
};
static LIST_HEAD(bcm_notifier_list);
static DEFINE_SPINLOCK(bcm_notifier_lock);
static struct bcm_sock *bcm_busy_notifier;
@@ -218,13 +218,11 @@ static int bcm_proc_show(struct seq_file *m, void *v)
struct net *net = m->private;
struct sock *sk = (struct sock *)pde_data(m->file->f_inode);
struct bcm_sock *bo = bcm_sk(sk);
struct bcm_op *op;
- seq_printf(m, ">>> socket %pK", sk->sk_socket);
- seq_printf(m, " / sk %pK", sk);
- seq_printf(m, " / bo %pK", bo);
+ seq_printf(m, ">>> sock inode %s", bo->procname);
seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs);
seq_printf(m, " / bound %s", bcm_proc_getifname(net, ifname, bo->ifindex));
seq_printf(m, " <<<\n");
rcu_read_lock();
@@ -1534,11 +1532,11 @@ static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
if (dev) {
err = can_rx_register(sock_net(sk), dev,
op->can_id,
REGMASK(op->can_id),
bcm_rx_handler, op,
- "bcm", sk);
+ sock_i_ino(sk), sk);
/* keep a tracked reference so that a later
* unregister can safely reach the device even
* if a concurrent NETDEV_UNREGISTER has
* already unlisted it by ifindex
@@ -1558,11 +1556,12 @@ static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
}
} else {
err = can_rx_register(sock_net(sk), NULL, op->can_id,
REGMASK(op->can_id),
- bcm_rx_handler, op, "bcm", sk);
+ bcm_rx_handler, op,
+ sock_i_ino(sk), sk);
}
if (err) {
/* newly created bcm rx op is broken -> remove it */
if (new_op) {
@@ -2039,11 +2038,11 @@ static int bcm_connect(struct socket *sock, struct sockaddr_unsized *uaddr, int
}
#if IS_ENABLED(CONFIG_PROC_FS)
if (net->can.bcmproc_dir) {
/* unique socket address as filename */
- sprintf(bo->procname, "%llu", sock_i_ino(sk));
+ sprintf(bo->procname, "%016llx", sock_i_ino(sk));
bo->bcm_proc_read = proc_create_net_single(bo->procname, 0644,
net->can.bcmproc_dir,
bcm_proc_show, sk);
if (!bo->bcm_proc_read) {
ret = -ENOMEM;
diff --git a/net/can/gw.c b/net/can/gw.c
index 0ec99f68aa45..f1f59c0c6fd6 100644
--- a/net/can/gw.c
+++ b/net/can/gw.c
@@ -574,11 +574,11 @@ static void can_can_gw_rcv(struct sk_buff *skb, void *data)
static inline int cgw_register_filter(struct net *net, struct cgw_job *gwj)
{
return can_rx_register(net, gwj->src.dev, gwj->ccgw.filter.can_id,
gwj->ccgw.filter.can_mask, can_can_gw_rcv,
- gwj, "gw", NULL);
+ gwj, 0, NULL);
}
static inline void cgw_unregister_filter(struct net *net, struct cgw_job *gwj)
{
can_rx_unregister(net, gwj->src.dev, gwj->ccgw.filter.can_id,
diff --git a/net/can/isotp.c b/net/can/isotp.c
index 155530aedce2..35ae4f51a525 100644
--- a/net/can/isotp.c
+++ b/net/can/isotp.c
@@ -1619,18 +1619,18 @@ static int isotp_bind(struct socket *sock, struct sockaddr_unsized *uaddr, int l
ifindex = dev->ifindex;
if (isotp_register_rxid(so))
can_rx_register(net, dev, rx_id, SINGLE_MASK(rx_id),
- isotp_rcv, sk, "isotp", sk);
+ isotp_rcv, sk, sock_i_ino(sk), sk);
/* no consecutive frame echo skb in flight */
WRITE_ONCE(so->cfecho, 0);
/* register for echo skb's */
can_rx_register(net, dev, tx_id, SINGLE_MASK(tx_id),
- isotp_rcv_echo, sk, "isotpe", sk);
+ isotp_rcv_echo, sk, sock_i_ino(sk), sk);
/* switch to new settings */
so->ifindex = ifindex;
so->rxid = rx_id;
so->txid = tx_id;
diff --git a/net/can/j1939/main.c b/net/can/j1939/main.c
index 5e5e6c228f22..d9384cf0e356 100644
--- a/net/can/j1939/main.c
+++ b/net/can/j1939/main.c
@@ -182,11 +182,11 @@ static int j1939_can_rx_register(struct j1939_priv *priv)
struct net_device *ndev = priv->ndev;
int ret;
j1939_priv_get(priv);
ret = can_rx_register(dev_net(ndev), ndev, J1939_CAN_ID, J1939_CAN_MASK,
- j1939_can_recv, priv, "j1939", NULL);
+ j1939_can_recv, priv, 0, NULL);
if (ret < 0) {
j1939_priv_put(priv);
return ret;
}
diff --git a/net/can/proc.c b/net/can/proc.c
index de4d05ae3459..b7858fb66178 100644
--- a/net/can/proc.c
+++ b/net/can/proc.c
@@ -189,30 +189,35 @@ static void can_print_rcvlist(struct seq_file *m, struct hlist_head *rx_list,
struct net_device *dev)
{
struct receiver *r;
hlist_for_each_entry_rcu(r, rx_list, list) {
- char *fmt = (r->can_id & CAN_EFF_FLAG)?
- " %-5s %08x %08x %pK %pK %8ld %s\n" :
- " %-5s %03x %08x %pK %pK %8ld %s\n";
+ char *fmt;
+#if IS_ENABLED(CONFIG_KALLSYMS)
+ fmt = (r->can_id & CAN_EFF_FLAG)?
+ " %6s %08x %08x %8ld %016llx %ps\n" :
+ " %6s %03x %08x %8ld %016llx %ps\n";
seq_printf(m, fmt, DNAME(dev), r->can_id, r->mask,
- r->func, r->data, atomic_long_read(&r->matches),
- r->ident);
+ atomic_long_read(&r->matches), r->ino, r->func);
+#else
+ fmt = (r->can_id & CAN_EFF_FLAG)?
+ " %6s %08x %08x %8ld %016llx (unknown)\n" :
+ " %6s %03x %08x %8ld %016llx (unknown)\n";
+ seq_printf(m, fmt, DNAME(dev), r->can_id, r->mask,
+ atomic_long_read(&r->matches), r->ino);
+#endif
}
}
static void can_print_recv_banner(struct seq_file *m)
{
/*
- * can1. 00000000 00000000 00000000
- * ....... 0 tp20
+ * device can_id can_mask matches sock_inode function
+ * vcan0 80000123 c00007ff 0 000000000000ab16 raw_rcv [can_raw]
*/
- if (IS_ENABLED(CONFIG_64BIT))
- seq_puts(m, " device can_id can_mask function userdata matches ident\n");
- else
- seq_puts(m, " device can_id can_mask function userdata matches ident\n");
+ seq_puts(m, " device can_id can_mask matches sock_inode function\n");
}
static int can_stats_proc_show(struct seq_file *m, void *v)
{
struct net *net = m->private;
diff --git a/net/can/raw.c b/net/can/raw.c
index 82d9c0499c95..0a8b7c2fb4c9 100644
--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -220,11 +220,11 @@ static int raw_enable_filters(struct net *net, struct net_device *dev,
int i;
for (i = 0; i < count; i++) {
err = can_rx_register(net, dev, filter[i].can_id,
filter[i].can_mask,
- raw_rcv, sk, "raw", sk);
+ raw_rcv, sk, sock_i_ino(sk), sk);
if (err) {
/* clean up successfully registered filters */
while (--i >= 0)
can_rx_unregister(net, dev, filter[i].can_id,
filter[i].can_mask,
@@ -241,11 +241,11 @@ static int raw_enable_errfilter(struct net *net, struct net_device *dev,
{
int err = 0;
if (err_mask)
err = can_rx_register(net, dev, 0, err_mask | CAN_ERR_FLAG,
- raw_rcv, sk, "raw", sk);
+ raw_rcv, sk, sock_i_ino(sk), sk);
return err;
}
static void raw_disable_filters(struct net *net, struct net_device *dev,
--
2.53.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [can-next] can: proc: remove pointers from CAN specific proc output
2026-08-14 10:54 [can-next] can: proc: remove pointers from CAN specific proc output Oliver Hartkopp
@ 2026-08-14 12:31 ` Sebastian Andrzej Siewior
2026-08-14 13:36 ` Oliver Hartkopp
0 siblings, 1 reply; 5+ messages in thread
From: Sebastian Andrzej Siewior @ 2026-08-14 12:31 UTC (permalink / raw)
To: Oliver Hartkopp; +Cc: linux-can, netdev
On 2026-08-14 12:54:38 [+0200], Oliver Hartkopp wrote:
…
> function names and sock inode numbers when available. As there's no known
> tooling around the CAN specific proc output breaking the ABI with this
> rework creates no issue.
I let you be the judge of that.
…
> --- a/Documentation/networking/can.rst
> +++ b/Documentation/networking/can.rst
> @@ -1040,19 +1040,19 @@ As described in :ref:`socketcan-receive-lists` the SocketCAN core uses several f
> lists to deliver received CAN frames to CAN protocol modules. These
> receive lists, their filters and the count of filter matches can be
> checked in the appropriate receive list. All entries contain the
> device and a protocol module identifier::
>
> - foo@bar:~$ cat /proc/net/can/rcvlist_all
> + foo@bar:~$ cat /proc/net/can/rcvlist_fil
Is this _fil a typo?
> - receive list 'rx_all':
> - (vcan3: no entry)
> - (vcan2: no entry)
> - (vcan1: no entry)
> - device can_id can_mask function userdata matches ident
> - vcan0 000 00000000 f88e6370 f6c6f400 0 raw
> + receive list 'rx_fil':
> (any: no entry)
> + device can_id can_mask matches sock_inode function
> + vcan0 80000123 c00007ff 0 000000000000f862 raw_rcv [can_raw]
> + (vcan1: no entry)
> + (vcan2: no entry)
> + (vcan3: no entry)
>
> In this example an application requests any CAN traffic from vcan0::
>
> rcvlist_all - list for unfiltered entries (no filter operations)
> rcvlist_eff - list for single extended frame (EFF) entries
…
> --- a/net/can/bcm.c
> +++ b/net/can/bcm.c
> @@ -2039,11 +2038,11 @@ static int bcm_connect(struct socket *sock, struct sockaddr_unsized *uaddr, int
> }
>
> #if IS_ENABLED(CONFIG_PROC_FS)
> if (net->can.bcmproc_dir) {
> /* unique socket address as filename */
> - sprintf(bo->procname, "%llu", sock_i_ino(sk));
> + sprintf(bo->procname, "%016llx", sock_i_ino(sk));
snprintf() would be a bit bulletproof
> bo->bcm_proc_read = proc_create_net_single(bo->procname, 0644,
> net->can.bcmproc_dir,
> bcm_proc_show, sk);
> if (!bo->bcm_proc_read) {
> ret = -ENOMEM;
…
> diff --git a/net/can/proc.c b/net/can/proc.c
> index de4d05ae3459..b7858fb66178 100644
> --- a/net/can/proc.c
> +++ b/net/can/proc.c
> @@ -189,30 +189,35 @@ static void can_print_rcvlist(struct seq_file *m, struct hlist_head *rx_list,
> struct net_device *dev)
> {
> struct receiver *r;
>
> hlist_for_each_entry_rcu(r, rx_list, list) {
> - char *fmt = (r->can_id & CAN_EFF_FLAG)?
> - " %-5s %08x %08x %pK %pK %8ld %s\n" :
> - " %-5s %03x %08x %pK %pK %8ld %s\n";
> + char *fmt;
>
> +#if IS_ENABLED(CONFIG_KALLSYMS)
Please don't. I fix %ps and then there is no leak. There will be then
the 0 and everything will be fine.
> + fmt = (r->can_id & CAN_EFF_FLAG)?
> + " %6s %08x %08x %8ld %016llx %ps\n" :
> + " %6s %03x %08x %8ld %016llx %ps\n";
> seq_printf(m, fmt, DNAME(dev), r->can_id, r->mask,
> - r->func, r->data, atomic_long_read(&r->matches),
> - r->ident);
> + atomic_long_read(&r->matches), r->ino, r->func);
> +#else
> + fmt = (r->can_id & CAN_EFF_FLAG)?
> + " %6s %08x %08x %8ld %016llx (unknown)\n" :
> + " %6s %03x %08x %8ld %016llx (unknown)\n";
> + seq_printf(m, fmt, DNAME(dev), r->can_id, r->mask,
> + atomic_long_read(&r->matches), r->ino);
> +#endif
> }
> }
…
So if you do this now, then I probably should remove that hunk from my
patch.
Sebastian
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [can-next] can: proc: remove pointers from CAN specific proc output
2026-08-14 12:31 ` Sebastian Andrzej Siewior
@ 2026-08-14 13:36 ` Oliver Hartkopp
2026-08-14 13:52 ` Sebastian Andrzej Siewior
0 siblings, 1 reply; 5+ messages in thread
From: Oliver Hartkopp @ 2026-08-14 13:36 UTC (permalink / raw)
To: Sebastian Andrzej Siewior; +Cc: linux-can, netdev
On 14.08.26 14:31, Sebastian Andrzej Siewior wrote:
> On 2026-08-14 12:54:38 [+0200], Oliver Hartkopp wrote:
> …
>> function names and sock inode numbers when available. As there's no known
>> tooling around the CAN specific proc output breaking the ABI with this
>> rework creates no issue.
>
> I let you be the judge of that.
>
> …
>> --- a/Documentation/networking/can.rst
>> +++ b/Documentation/networking/can.rst
>> @@ -1040,19 +1040,19 @@ As described in :ref:`socketcan-receive-lists` the SocketCAN core uses several f
>> lists to deliver received CAN frames to CAN protocol modules. These
>> receive lists, their filters and the count of filter matches can be
>> checked in the appropriate receive list. All entries contain the
>> device and a protocol module identifier::
>>
>> - foo@bar:~$ cat /proc/net/can/rcvlist_all
>> + foo@bar:~$ cat /proc/net/can/rcvlist_fil
>
> Is this _fil a typo?
No, it's a slightly different example.
>> - receive list 'rx_all':
>> - (vcan3: no entry)
>> - (vcan2: no entry)
>> - (vcan1: no entry)
>> - device can_id can_mask function userdata matches ident
>> - vcan0 000 00000000 f88e6370 f6c6f400 0 raw
>> + receive list 'rx_fil':
>> (any: no entry)
>> + device can_id can_mask matches sock_inode function
>> + vcan0 80000123 c00007ff 0 000000000000f862 raw_rcv [can_raw]
>> + (vcan1: no entry)
>> + (vcan2: no entry)
>> + (vcan3: no entry)
>>
>> In this example an application requests any CAN traffic from vcan0::
>>
>> rcvlist_all - list for unfiltered entries (no filter operations)
>> rcvlist_eff - list for single extended frame (EFF) entries
> …
>> --- a/net/can/bcm.c
>> +++ b/net/can/bcm.c
>> @@ -2039,11 +2038,11 @@ static int bcm_connect(struct socket *sock, struct sockaddr_unsized *uaddr, int
>> }
>>
>> #if IS_ENABLED(CONFIG_PROC_FS)
>> if (net->can.bcmproc_dir) {
>> /* unique socket address as filename */
>> - sprintf(bo->procname, "%llu", sock_i_ino(sk));
>> + sprintf(bo->procname, "%016llx", sock_i_ino(sk));
>
> snprintf() would be a bit bulletproof
>
Will change that in v2
>> bo->bcm_proc_read = proc_create_net_single(bo->procname, 0644,
>> net->can.bcmproc_dir,
>> bcm_proc_show, sk);
>> if (!bo->bcm_proc_read) {
>> ret = -ENOMEM;
> …
>> diff --git a/net/can/proc.c b/net/can/proc.c
>> index de4d05ae3459..b7858fb66178 100644
>> --- a/net/can/proc.c
>> +++ b/net/can/proc.c
>> @@ -189,30 +189,35 @@ static void can_print_rcvlist(struct seq_file *m, struct hlist_head *rx_list,
>> struct net_device *dev)
>> {
>> struct receiver *r;
>>
>> hlist_for_each_entry_rcu(r, rx_list, list) {
>> - char *fmt = (r->can_id & CAN_EFF_FLAG)?
>> - " %-5s %08x %08x %pK %pK %8ld %s\n" :
>> - " %-5s %03x %08x %pK %pK %8ld %s\n";
>> + char *fmt;
>>
>> +#if IS_ENABLED(CONFIG_KALLSYMS)
>
> Please don't. I fix %ps and then there is no leak. There will be then
> the 0 and everything will be fine.
>
I can wait for your changes before the v2 posting.
Btw. do you think "0" is a good return value, when people expect a
function name?
What about "(unknown)" or something similar?
>> + fmt = (r->can_id & CAN_EFF_FLAG)?
>> + " %6s %08x %08x %8ld %016llx %ps\n" :
>> + " %6s %03x %08x %8ld %016llx %ps\n";
>> seq_printf(m, fmt, DNAME(dev), r->can_id, r->mask,
>> - r->func, r->data, atomic_long_read(&r->matches),
>> - r->ident);
>> + atomic_long_read(&r->matches), r->ino, r->func);
>> +#else
>> + fmt = (r->can_id & CAN_EFF_FLAG)?
>> + " %6s %08x %08x %8ld %016llx (unknown)\n" :
>> + " %6s %03x %08x %8ld %016llx (unknown)\n";
>> + seq_printf(m, fmt, DNAME(dev), r->can_id, r->mask,
>> + atomic_long_read(&r->matches), r->ino);
>> +#endif
>> }
>> }
> …
>
> So if you do this now, then I probably should remove that hunk from my
> patch.
IMHO these /proc/net/can changes go far beyond replacing the pointer
values with "0".
I hope the
Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
is ok for your attribution?!?
Best regards,
Oliver
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [can-next] can: proc: remove pointers from CAN specific proc output
2026-08-14 13:36 ` Oliver Hartkopp
@ 2026-08-14 13:52 ` Sebastian Andrzej Siewior
2026-08-14 13:57 ` Oliver Hartkopp
0 siblings, 1 reply; 5+ messages in thread
From: Sebastian Andrzej Siewior @ 2026-08-14 13:52 UTC (permalink / raw)
To: Oliver Hartkopp; +Cc: linux-can, netdev
On 2026-08-14 15:36:03 [+0200], Oliver Hartkopp wrote:
> > > --- a/Documentation/networking/can.rst
> > > +++ b/Documentation/networking/can.rst
> > > @@ -1040,19 +1040,19 @@ As described in :ref:`socketcan-receive-lists` the SocketCAN core uses several f
> > > lists to deliver received CAN frames to CAN protocol modules. These
> > > receive lists, their filters and the count of filter matches can be
> > > checked in the appropriate receive list. All entries contain the
> > > device and a protocol module identifier::
> > > - foo@bar:~$ cat /proc/net/can/rcvlist_all
> > > + foo@bar:~$ cat /proc/net/can/rcvlist_fil
> >
> > Is this _fil a typo?
>
> No, it's a slightly different example.
okay then.
> > > diff --git a/net/can/proc.c b/net/can/proc.c
> > > index de4d05ae3459..b7858fb66178 100644
> > > --- a/net/can/proc.c
> > > +++ b/net/can/proc.c
> > > @@ -189,30 +189,35 @@ static void can_print_rcvlist(struct seq_file *m, struct hlist_head *rx_list,
> > > struct net_device *dev)
> > > {
> > > struct receiver *r;
> > > hlist_for_each_entry_rcu(r, rx_list, list) {
> > > - char *fmt = (r->can_id & CAN_EFF_FLAG)?
> > > - " %-5s %08x %08x %pK %pK %8ld %s\n" :
> > > - " %-5s %03x %08x %pK %pK %8ld %s\n";
> > > + char *fmt;
> > > +#if IS_ENABLED(CONFIG_KALLSYMS)
> >
> > Please don't. I fix %ps and then there is no leak. There will be then
> > the 0 and everything will be fine.
> >
>
> I can wait for your changes before the v2 posting.
>
> Btw. do you think "0" is a good return value, when people expect a function
> name?
>
> What about "(unknown)" or something similar?
Yeah, that '(unknown)' looks slightly better.
> > > + fmt = (r->can_id & CAN_EFF_FLAG)?
> > > + " %6s %08x %08x %8ld %016llx %ps\n" :
> > > + " %6s %03x %08x %8ld %016llx %ps\n";
> > > seq_printf(m, fmt, DNAME(dev), r->can_id, r->mask,
> > > - r->func, r->data, atomic_long_read(&r->matches),
> > > - r->ident);
> > > + atomic_long_read(&r->matches), r->ino, r->func);
> > > +#else
> > > + fmt = (r->can_id & CAN_EFF_FLAG)?
> > > + " %6s %08x %08x %8ld %016llx (unknown)\n" :
> > > + " %6s %03x %08x %8ld %016llx (unknown)\n";
> > > + seq_printf(m, fmt, DNAME(dev), r->can_id, r->mask,
> > > + atomic_long_read(&r->matches), r->ino);
> > > +#endif
> > > }
> > > }
> > …
> >
> > So if you do this now, then I probably should remove that hunk from my
> > patch.
>
> IMHO these /proc/net/can changes go far beyond replacing the pointer values
> with "0".
>
> I hope the
> Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> is ok for your attribution?!?
That is fine. I just mean I should drop that hunk and repost to avoid
the pointless collision here.
> Best regards,
> Oliver
Sebastian
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [can-next] can: proc: remove pointers from CAN specific proc output
2026-08-14 13:52 ` Sebastian Andrzej Siewior
@ 2026-08-14 13:57 ` Oliver Hartkopp
0 siblings, 0 replies; 5+ messages in thread
From: Oliver Hartkopp @ 2026-08-14 13:57 UTC (permalink / raw)
To: Sebastian Andrzej Siewior; +Cc: linux-can, netdev
On 14.08.26 15:52, Sebastian Andrzej Siewior wrote:
> On 2026-08-14 15:36:03 [+0200], Oliver Hartkopp wrote:
>>>> --- a/Documentation/networking/can.rst
>>>> +++ b/Documentation/networking/can.rst
>>>> @@ -1040,19 +1040,19 @@ As described in :ref:`socketcan-receive-lists` the SocketCAN core uses several f
>>>> lists to deliver received CAN frames to CAN protocol modules. These
>>>> receive lists, their filters and the count of filter matches can be
>>>> checked in the appropriate receive list. All entries contain the
>>>> device and a protocol module identifier::
>>>> - foo@bar:~$ cat /proc/net/can/rcvlist_all
>>>> + foo@bar:~$ cat /proc/net/can/rcvlist_fil
>>>
>>> Is this _fil a typo?
>>
>> No, it's a slightly different example.
> okay then.
>
>>>> diff --git a/net/can/proc.c b/net/can/proc.c
>>>> index de4d05ae3459..b7858fb66178 100644
>>>> --- a/net/can/proc.c
>>>> +++ b/net/can/proc.c
>>>> @@ -189,30 +189,35 @@ static void can_print_rcvlist(struct seq_file *m, struct hlist_head *rx_list,
>>>> struct net_device *dev)
>>>> {
>>>> struct receiver *r;
>>>> hlist_for_each_entry_rcu(r, rx_list, list) {
>>>> - char *fmt = (r->can_id & CAN_EFF_FLAG)?
>>>> - " %-5s %08x %08x %pK %pK %8ld %s\n" :
>>>> - " %-5s %03x %08x %pK %pK %8ld %s\n";
>>>> + char *fmt;
>>>> +#if IS_ENABLED(CONFIG_KALLSYMS)
>>>
>>> Please don't. I fix %ps and then there is no leak. There will be then
>>> the 0 and everything will be fine.
>>>
>>
>> I can wait for your changes before the v2 posting.
>>
>> Btw. do you think "0" is a good return value, when people expect a function
>> name?
>>
>> What about "(unknown)" or something similar?
>
> Yeah, that '(unknown)' looks slightly better.
>
>>>> + fmt = (r->can_id & CAN_EFF_FLAG)?
>>>> + " %6s %08x %08x %8ld %016llx %ps\n" :
>>>> + " %6s %03x %08x %8ld %016llx %ps\n";
>>>> seq_printf(m, fmt, DNAME(dev), r->can_id, r->mask,
>>>> - r->func, r->data, atomic_long_read(&r->matches),
>>>> - r->ident);
>>>> + atomic_long_read(&r->matches), r->ino, r->func);
>>>> +#else
>>>> + fmt = (r->can_id & CAN_EFF_FLAG)?
>>>> + " %6s %08x %08x %8ld %016llx (unknown)\n" :
>>>> + " %6s %03x %08x %8ld %016llx (unknown)\n";
>>>> + seq_printf(m, fmt, DNAME(dev), r->can_id, r->mask,
>>>> + atomic_long_read(&r->matches), r->ino);
>>>> +#endif
>>>> }
>>>> }
>>> …
>>>
>>> So if you do this now, then I probably should remove that hunk from my
>>> patch.
>>
>> IMHO these /proc/net/can changes go far beyond replacing the pointer values
>> with "0".
>>
>> I hope the
>> Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
>> is ok for your attribution?!?
>
> That is fine. I just mean I should drop that hunk and repost to avoid
> the pointless collision here.
Yep. Thanks!
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2026-08-14 13:57 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-08-14 10:54 [can-next] can: proc: remove pointers from CAN specific proc output Oliver Hartkopp
2026-08-14 12:31 ` Sebastian Andrzej Siewior
2026-08-14 13:36 ` Oliver Hartkopp
2026-08-14 13:52 ` Sebastian Andrzej Siewior
2026-08-14 13:57 ` Oliver Hartkopp
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox