2013-04-08 09:30:02

by Martin Pitt

[permalink] [raw]
Subject: [PATCH v2] mac80211_hwsim: Register and bind to driver

Properly register our mac80211_hwsim_driver, attach it to the platform bus.
Bind newly created hwsim devices to that driver, so that our wlan devices get
a proper "driver" sysfs attribute.

This makes mac80211_hwsim interfaces work with NetworkManager.

Signed-off-by: Martin Pitt <[email protected]>
---
drivers/net/wireless/mac80211_hwsim.c | 18 +++++++++++++++++-
1 files changed, 17 insertions(+), 1 deletions(-)

diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c
index 0064d38..0a6fb4a 100644
--- a/drivers/net/wireless/mac80211_hwsim.c
+++ b/drivers/net/wireless/mac80211_hwsim.c
@@ -25,6 +25,7 @@
#include <linux/if_arp.h>
#include <linux/rtnetlink.h>
#include <linux/etherdevice.h>
+#include <linux/platform_device.h>
#include <linux/debugfs.h>
#include <linux/module.h>
#include <linux/ktime.h>
@@ -1675,6 +1676,7 @@ static void mac80211_hwsim_free(void)
debugfs_remove(data->debugfs_ps);
debugfs_remove(data->debugfs);
ieee80211_unregister_hw(data->hw);
+ device_release_driver(data->dev);
device_unregister(data->dev);
ieee80211_free_hw(data->hw);
}
@@ -1683,7 +1685,9 @@ static void mac80211_hwsim_free(void)


static struct device_driver mac80211_hwsim_driver = {
- .name = "mac80211_hwsim"
+ .name = "mac80211_hwsim",
+ .bus = &platform_bus_type,
+ .owner = THIS_MODULE,
};

static const struct net_device_ops hwsim_netdev_ops = {
@@ -2179,6 +2183,8 @@ static int __init init_mac80211_hwsim(void)
if (IS_ERR(hwsim_class))
return PTR_ERR(hwsim_class);

+ driver_register(&mac80211_hwsim_driver);
+
memset(addr, 0, ETH_ALEN);
addr[0] = 0x02;

@@ -2205,6 +2211,14 @@ static int __init init_mac80211_hwsim(void)
goto failed_drvdata;
}
data->dev->driver = &mac80211_hwsim_driver;
+ err = device_bind_driver(data->dev);
+ if (err != 0) {
+ printk(KERN_DEBUG
+ "mac80211_hwsim: device_bind_driver "
+ "failed (%d)\n", err);
+ goto failed_hw;
+ }
+
skb_queue_head_init(&data->pending);

SET_IEEE80211_DEV(hw, data->dev);
@@ -2506,6 +2520,7 @@ failed_drvdata:
ieee80211_free_hw(hw);
failed:
mac80211_hwsim_free();
+ driver_unregister(&mac80211_hwsim_driver);
return err;
}
module_init(init_mac80211_hwsim);
@@ -2518,5 +2533,6 @@ static void __exit exit_mac80211_hwsim(void)

mac80211_hwsim_free();
unregister_netdev(hwsim_mon);
+ driver_unregister(&mac80211_hwsim_driver);
}
module_exit(exit_mac80211_hwsim);
--
1.7.2.5

Martin Pitt | http://www.piware.de
Ubuntu Developer (http://www.ubuntu.com) | Debian Developer (http://www.debian.org)


2013-04-24 04:14:51

by Sasha Levin

[permalink] [raw]
Subject: Re: [PATCH v2] mac80211_hwsim: Register and bind to driver

On 04/08/2013 10:32 AM, Johannes Berg wrote:
> On Mon, 2013-04-08 at 11:30 +0200, Martin Pitt wrote:
>> Properly register our mac80211_hwsim_driver, attach it to the platform bus.
>> Bind newly created hwsim devices to that driver, so that our wlan devices get
>> a proper "driver" sysfs attribute.
>>
>> This makes mac80211_hwsim interfaces work with NetworkManager.
>
> Applied.

Hi guys,

The registration of the driver here is somewhat odd.

You're trying to register a platform driver, but are not actually creating
a struct platform_driver at any point. This makes registration do the wrong
thing.

Simply booting a kernel with that patch would cause it to blow up because
running to_platform_driver() on the device_driver object would point to garbage:

[ 25.349569] BUG: unable to handle kernel NULL pointer dereference at 0000000000000001
[ 25.350254] IP: [<ffffffff81f39fa5>] platform_match+0x45/0xc0
[ 25.350886] PGD 0
[ 25.351141] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
[ 25.351775] Dumping ftrace buffer:
[ 25.352174] (ftrace buffer empty)
[ 25.352581] Modules linked in:
[ 25.352949] CPU: 3 PID: 1 Comm: swapper/0 Tainted: G W 3.9.0-rc8-next-20130423-sasha-00013-gff425d3-dirty #350
[ 25.353905] task: ffff8800b9f08000 ti: ffff8800b9f10000 task.ti: ffff8800b9f10000
[ 25.354577] RIP: 0010:[<ffffffff81f39fa5>] [<ffffffff81f39fa5>] platform_match+0x45/0xc0
[ 25.355485] RSP: 0000:ffff8800b9f11c98 EFLAGS: 00010202
[ 25.356307] RAX: 000000000000000e RBX: ffff8800b9ad9be8 RCX: 00000000f4b5f4b4
[ 25.357184] RDX: ffff8800b9f08000 RSI: 0000000000000001 RDI: 0000000000000282
[ 25.357939] RBP: ffff8800b9f11cb8 R08: 0000000000000002 R09: 0000000000000000
[ 25.358791] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff86083640
[ 25.359134] R13: 0000000000000001 R14: 0000000000000000 R15: ffffffff85f963c0
[ 25.359134] FS: 0000000000000000(0000) GS:ffff8800bba00000(0000) knlGS:0000000000000000
[ 25.359134] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 25.359134] CR2: 0000000000000001 CR3: 0000000005826000 CR4: 00000000000406e0
[ 25.359134] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 25.359134] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[ 25.359134] Stack:
[ 25.359134] ffff8800b9f11cd8 ffff8800b9ad9be8 ffffffff86083640 ffffffff81f37f90
[ 25.359134] ffff8800b9f11ce8 ffffffff81f37fca 0000000000000000 0000000000000000
[ 25.359134] ffffffff86083640 ffffffff81f37f90 ffff8800b9f11d28 ffffffff81f35ca1
[ 25.359134] Call Trace:
[ 25.359134] [<ffffffff81f37f90>] ? driver_probe_device+0x340/0x340
[ 25.359134] [<ffffffff81f37fca>] __driver_attach+0x3a/0xb0
[ 25.359134] [<ffffffff81f37f90>] ? driver_probe_device+0x340/0x340
[ 25.359134] [<ffffffff81f35ca1>] bus_for_each_dev+0x61/0xa0
[ 25.359134] [<ffffffff81f37629>] driver_attach+0x19/0x20
[ 25.359134] [<ffffffff81f37198>] bus_add_driver+0x118/0x2a0
[ 25.359134] [<ffffffff8668694e>] ? wil6210_driver_init+0x1b/0x1b
[ 25.359134] [<ffffffff81f38778>] driver_register+0xa8/0x170
[ 25.359134] [<ffffffff8668694e>] ? wil6210_driver_init+0x1b/0x1b
[ 25.359134] [<ffffffff8668694e>] ? wil6210_driver_init+0x1b/0x1b
[ 25.359134] [<ffffffff86686a3e>] init_mac80211_hwsim+0xf0/0xaaa
[ 25.359134] [<ffffffff86686933>] ? ar5523_driver_init+0x1b/0x1b
[ 25.359134] [<ffffffff86686933>] ? ar5523_driver_init+0x1b/0x1b
[ 25.359134] [<ffffffff8668694e>] ? wil6210_driver_init+0x1b/0x1b
[ 25.359134] [<ffffffff810020f2>] do_one_initcall+0xb2/0x1b0
[ 25.359134] [<ffffffff865f3021>] kernel_init_freeable+0x15d/0x1ef
[ 25.359134] [<ffffffff865f2801>] ? loglevel+0x31/0x31
[ 25.359134] [<ffffffff83f8ebd0>] ? rest_init+0x140/0x140
[ 25.359134] [<ffffffff83f8ebd9>] kernel_init+0x9/0xf0
[ 25.359134] [<ffffffff83fff1fc>] ret_from_fork+0x7c/0xb0
[ 25.359134] [<ffffffff83f8ebd0>] ? rest_init+0x140/0x140
[ 25.359134] Code: 48 8b 7e 30 48 89 de e8 5d d7 c5 ff 48 85 c0 75 75 48 8b 73 f0 48 c7 c7 fa a0 20 85 e8 74 01 07 02 4d 8b 6c
24 78 4d 85 ed 74 43 <41> 80 7d 00 00 74 2f 4c 8b 63 f0 4c 89 ee 4c 89 e7 e8 35 1e ae
[ 25.359134] RIP [<ffffffff81f39fa5>] platform_match+0x45/0xc0
[ 25.359134] RSP <ffff8800b9f11c98>
[ 25.359134] CR2: 0000000000000001
[ 25.386186] ---[ end trace 6293fa4fd2b61873 ]---

I don't have the hardware to test out any changes I do, but I'll send out a patch
tomorrow to try and fix that unless someone beats me to it.


Thanks,
Sasha

2013-04-08 14:55:42

by Martin Pitt

[permalink] [raw]
Subject: Re: [PATCH v2] mac80211_hwsim: Register and bind to driver

Hello Johannes,

Johannes Berg [2013-04-08 16:32 +0200]:
> On Mon, 2013-04-08 at 11:30 +0200, Martin Pitt wrote:
> > Properly register our mac80211_hwsim_driver, attach it to the platform bus.
> > Bind newly created hwsim devices to that driver, so that our wlan devices get
> > a proper "driver" sysfs attribute.
> >
> > This makes mac80211_hwsim interfaces work with NetworkManager.
>
> Applied.

Splendid, thank you!

Martin

--
Martin Pitt | http://www.piware.de
Ubuntu Developer (http://www.ubuntu.com) | Debian Developer (http://www.debian.org)

2013-04-08 14:32:56

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH v2] mac80211_hwsim: Register and bind to driver

On Mon, 2013-04-08 at 11:30 +0200, Martin Pitt wrote:
> Properly register our mac80211_hwsim_driver, attach it to the platform bus.
> Bind newly created hwsim devices to that driver, so that our wlan devices get
> a proper "driver" sysfs attribute.
>
> This makes mac80211_hwsim interfaces work with NetworkManager.

Applied.

johannes