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 -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
