Thread (5 messages) flat view 5 messages, 2 authors, 3d ago

Re: [can-next] can: proc: remove pointers from CAN specific proc output

From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: 2026-08-14 12:31:45
Also in: linux-can

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.

…
quoted hunk ↗ jump to hunk
--- 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
quoted hunk ↗ jump to hunk
--- 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;
quoted hunk ↗ jump to hunk
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
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