[PATCH] fix oops when reading /proc/ioports

[Igor Popik <igor.popik@gmail.com>]

Hi,

I have noticed that in recent kernels (2.6.13 and never) I got an oops
every time I tried to read /proc/ioports after trying to load i82365
pcmcia driver module:

root@alien2:~# modprobe i82365
FATAL: Error inserting i82365
(/lib/modules/2.6.14-rc3/kernel/drivers/pcmcia/i82365.ko): No such
device

root@alien2:~# cat /proc/ioports
<1>Unable to handle kernel paging request at virtual address cff10802
 printing eip:
c01c09bc
*pde = 0eec3067
*pte = 00000000
Oops: 0000 [#4]
Modules linked in: rsrc_nonstatic pcmcia_core snd_via82xx gameport
snd_ac97_codec snd_ac97_bus snd_pcm snd_timer
snd_page_alloc
snd_mpu401_uart snd_rawmidi snd soundcore psmouse
CPU:    0
EIP:    0060:[<c01c09bc>]    Not tainted VLI
EFLAGS: 00010297   (2.6.14-rc3)
EIP is at vsnprintf+0x33c/0x4d0
eax: cff10802   ebx: 0000000a   ecx: cff10802   edx: fffffffe
esi: ce525122   edi: 00000000   ebp: ce525fff   esp: c70e5eb4
ds: 007b   es: 007b   ss: 0068
Process cat (pid: 3365, threadinfo=c70e4000 task=c13b1030)
Stack: ce52511b ce525fff 000003e1 00000000 00000010 00000004 00000002 00000001
       ffffffff ffffffff c30747e0 c7f6efc0 c30747e0 00000116 c01723d5 ce525116
       00000eea c0333dc8 c70e5f2c 00000004 c011cc87 c30747e0 c0333db6 00000000
Call Trace:
 [<c01723d5>] seq_printf+0x35/0x60
 [<c011cc87>] r_show+0x77/0x80
 [<c0171ed6>] seq_read+0x1d6/0x2d0
 [<c01521a7>] vfs_read+0xa7/0x180
 [<c0152561>] sys_read+0x51/0x80
 [<c0103095>] syscall_call+0x7/0xb
Code: 24 08 00 00 00 83 cf 01 eb bb 8b 44 24 48 8b 54 24 20 83 44 24
48 04 8b 08 b8 ac ed 33 c0 81 f9 ff 0f 00 00 0f 46 c8
89 c8 eb 06 <80> 38 00 74 07 40 4a 83 fa ff 75 f4 29 c8 83 e7 10 89 c3 75 20
 Segmentation fault

This oops is caused by broken i82365 PCMCIA driver. Someone tried to
remove deprecated check_region()  but after the changes the driver
does not release its memory regions correctly.

I've attached patch that fixes that oops. This driver looks really
dirty, and I do not know if it still works.

Cheers,
Igor

Signed-off-by: Igor Popik <igor.popik@gmail.com>

--- a/drivers/pcmcia/i82365.c	2005-08-29 01:41:01.000000000 +0200
+++ b/drivers/pcmcia/i82365.c	2005-10-05 00:07:04.000000000 +0200
@@ -697,6 +697,11 @@
     struct i82365_socket *t = &socket[sockets-ns];

     base = sockets-ns;
+    if (t->ioaddr > 0) {
+	if (!request_region(t->ioaddr, 2, "i82365"))
+	    printk(KERN_WARNING "port conflict at %#lx\n", t->ioaddr);
+    }
+
     if (base == 0) printk("\n");
     printk(KERN_INFO "  %s", pcic[type].name);
     printk(" ISA-to-PCMCIA at port %#lx ofs 0x%02x",
@@ -806,7 +811,8 @@
 	if (sockets == 0)
 	    printk("port conflict at %#lx\n", i365_base);
 	return;
-    }
+    } else
+	release_region(i365_base, 2);

     id = identify(i365_base, 0);
     if ((id == IS_I82365DF) && (identify(i365_base, 1) != id)) {
@@ -1440,7 +1446,6 @@
 	i365_set(i, I365_CSCINT, 0);
 	release_region(socket[i].ioaddr, 2);
     }
-    release_region(i365_base, 2);
 #ifdef CONFIG_PNP
     if (i82365_pnpdev)
     		pnp_disable_dev(i82365_pnpdev);