[PATCH] Unloading of psnap

Petr Vandrovec (vandrove@vc.cvut.cz)
Mon, 22 Jul 2002 23:28:47 +0200


Hi Dave,
during my work on removing cli/sti from these two files I found that
removing psnap causes kernel to crash because of it does not unregister
from 802.2 layer.

While I was on it, I also added MOD_INC_USE_COUNT/MOD_DEC_USE_COUNT
into both 802.2 and SNAP. It is not strictly required as all callers
should have reference by name to register_*_client function, but I do not
think that MOD_*_USE_COUNT will slow code down, and now it is directly
visible how many snap and 802.2 clients live on system. And I'm sure
that somebody could through inter_module_get arrange some call path
so that we could unload p8022/psnap while still having some clients
registered.
Thanks,
Petr Vandrovec
vandrove@vc.cvut.cz

diff linux-2.5.27-c683/net/802/p8022.c.orig linux-2.5.27-c683/net/802/p8022.c
--- linux-2.5.27-c683/net/802/p8022.c.orig 2002-07-22 21:32:20.000000000 +0200
+++ linux-2.5.27-c683/net/802/p8022.c 2002-07-22 23:12:43.000000000 +0200
@@ -95,6 +95,7 @@
goto out;
proto = kmalloc(sizeof(*proto), GFP_ATOMIC);
if (proto) {
+ MOD_INC_USE_COUNT;
proto->type[0] = type;
proto->type_len = 1;
proto->rcvfunc = rcvfunc;
@@ -121,6 +122,7 @@
*clients = tmp->next;
kfree(tmp);
llc_unregister_sap(type);
+ MOD_DEC_USE_COUNT;
break;
}
clients = &tmp->next;
diff linux-2.5.27-c683/net/802/psnap.c.orig linux-2.5.27-c683/net/802/psnap.c
--- linux-2.5.27-c683/net/802/psnap.c.orig 2002-07-22 21:52:11.000000000 +0200
+++ linux-2.5.27-c683/net/802/psnap.c 2002-07-22 23:14:34.000000000 +0200
@@ -103,7 +103,14 @@
printk("SNAP - unable to register with 802.2\n");
return 0;
}
+
+static void __exit snap_exit(void)
+{
+ unregister_8022_client(0xAA);
+}
+
module_init(snap_init);
+module_exit(snap_exit);

/*
* Register SNAP clients. We don't yet use this for IP.
@@ -121,6 +128,7 @@
proto = (struct datalink_proto *) kmalloc(sizeof(*proto), GFP_ATOMIC);
if (proto != NULL)
{
+ MOD_INC_USE_COUNT;
memcpy(proto->type, desc,5);
proto->type_len = 5;
proto->rcvfunc = rcvfunc;
@@ -152,6 +160,7 @@
{
*clients = tmp->next;
kfree(tmp);
+ MOD_DEC_USE_COUNT;
break;
}
else
-
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