Greetings, Here is an USB WARNING triggered by Rob's test patch. https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master commit bea5b158ff0da9c7246ff391f754f5f38e34577a Author: Rob Herring <robh(a)kernel.org&gt; AuthorDate: Thu Aug 11 10:20:58 2016 -0500 Commit: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org&gt; CommitDate: Wed Aug 31 15:13:55 2016 +0200 driver core: add test of driver remove calls during probe In recent discussions on ksummit-discuss[1], it was suggested to do a sequence of probe, remove, probe for testing driver remove paths. This adds a kconfig option for said test. [1] https://lists.linuxfoundation.org/pipermail/ksummit-discuss/2016-August/0... Suggested-by: Arnd Bergmann <arnd(a)arndb.de&gt; Cc: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org&gt; Signed-off-by: Rob Herring <robh(a)kernel.org&gt; Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org&gt; +---------------------------------------------------+------------+------------+------------+ | | cebf8fd169 | bea5b158ff | 5cc3c0a7bf | +---------------------------------------------------+------------+------------+------------+ | boot_successes | 416 | 21 | 1 | | boot_failures | 4 | 76 | 12 | | BUG:kernel_reboot-without-warning_in_test_stage | 4 | | | | calltrace:init | 0 | 76 | | | WARNING:at_lib/kobject.c:#kobject_get | 0 | 67 | 8 | | INFO:task_blocked_for_more_than#seconds | 0 | 28 | 7 | | calltrace:kernfs_notify_workfn | 0 | 23 | | | calltrace:ret_from_fork | 0 | 28 | | | RIP:__default_send_IPI_dest_field | 0 | 28 | | | calltrace:watchdog | 0 | 28 | | | RIP:kernfs_link_sibling | 0 | 9 | | | Kernel_panic-not_syncing:hung_task:blocked_tasks | 0 | 28 | 7 | | BUG:unable_to_handle_kernel | 0 | 3 | 2 | | Oops | 0 | 3 | 2 | | RIP:kobject_get | 0 | 3 | | | Kernel_panic-not_syncing:Fatal_exception | 0 | 3 | 2 | | RIP:__sanitizer_cov_trace_pc | 0 | 19 | | | WARNING:at_drivers/usb/core/urb.c:#usb_submit_urb | 0 | 6 | | | calltrace:hub_init_func2 | 0 | 2 | | | calltrace:pm_runtime_work | 0 | 4 | | | calltrace:ring_buffer_producer_thread | 0 | 1 | | | calltrace:usb_gadget_state_work | 0 | 5 | | | BUG:kernel_hang_in_test_stage | 0 | 39 | 3 | | WARNING:at_kernel/workqueue.c:#worker_thread | 0 | 1 | | +---------------------------------------------------+------------+------------+------------+ [ 21.806527] hub 1-0:1.0: 1 port detected [ 21.809142] kobject (ffff88001cb86f78): tried to init an initialized object, something is seriously wrong. [ 21.810522] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.8.0-rc4-00003-gbea5b15 #1 [ 21.824599] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.3-20161025_171302-gandalf 04/01/2014 [ 21.826031] 0000000000000297 ffff88001f7c3b48 ffffffff9efb5abe ffff88001cb86f78 [ 21.827157] ffffffffa06ab160 ffff88001cb86ed8 ffff88001cb51820 ffff88001f7c3b68 [ 21.828286] ffffffff9efb8f05 ffff88001cb86f68 ffff88001cb86f68 ffff88001f7c3b80 [ 21.829416] Call Trace: [ 21.829781] [<ffffffff9efb5abe>] dump_stack+0xb6/0x118 [ 21.830527] [<ffffffff9efb8f05>] kobject_init+0xa5/0xb0 [ 21.831282] [<ffffffff9f57b1fd>] device_initialize+0x2d/0xf0 [ 21.832097] [<ffffffff9f57bf2a>] device_register+0x1a/0x30 [ 21.832888] [<ffffffff9f732626>] usb_add_gadget_udc_release+0xc6/0x370 [ 21.833813] [<ffffffff9f732994>] usb_add_gadget_udc+0x24/0x30 [ 21.847657] [<ffffffff9f7361d1>] dummy_udc_probe+0x1e1/0x240 [ 21.848476] [<ffffffff9f735ff0>] ? dummy_free_request+0xc0/0xc0 [ 21.849348] [<ffffffff9f582c1e>] platform_drv_probe+0x4e/0xd0 [ 21.850181] [<ffffffff9f582bd0>] ? platform_drv_remove+0x60/0x60 [ 21.851049] [<ffffffff9f580eb2>] driver_probe_device+0xd2/0x490 [ 21.851907] [<ffffffff9f581411>] __device_attach_driver+0xb1/0xf0 [ 21.852780] [<ffffffff9f581360>] ? __driver_attach+0xf0/0xf0 [ 21.853598] [<ffffffff9f57eeb2>] bus_for_each_drv+0x92/0xe0 [ 21.854405] [<ffffffff9f580c41>] __device_attach+0xf1/0x170 [ 21.855214] [<ffffffff9f5814bf>] device_initial_probe+0x1f/0x30 [ 21.856068] [<ffffffff9f57f20e>] bus_probe_device+0xde/0xf0 [ 21.856867] [<ffffffff9f57bb6e>] device_add+0x50e/0x780 [ 21.857624] [<ffffffff9f5835d5>] platform_device_add+0xf5/0x2d0 [ 21.858477] [<ffffffffa0a96198>] init+0x328/0x49a [ 21.859175] [<ffffffffa0a95e70>] ? trace_event_define_fields_udc_log_req+0x25a/0x25a [ 21.873293] [<ffffffffa0a4041c>] do_one_initcall+0xa5/0x191 [ 21.874108] [<ffffffffa0a4072d>] kernel_init_freeable+0x225/0x2cd [ 21.874995] [<ffffffff9faffe98>] kernel_init+0x18/0x180 [ 21.875755] [<ffffffff9fb1034f>] ret_from_fork+0x1f/0x40 [ 21.876528] [<ffffffff9faffe80>] ? rest_init+0xd0/0xd0 [ 21.877477] ------------[ cut here ]------------ [ 21.878158] WARNING: CPU: 0 PID: 1 at lib/kobject.c:597 kobject_get+0xd6/0x100 [ 21.879584] kobject: '(null)' (ffff88001cb82a70): is not initialized, yet kobject_get() is being called. [ 21.880940] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.8.0-rc4-00003-gbea5b15 #1 [ 21.881997] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.3-20161025_171302-gandalf 04/01/2014 [ 21.883418] 0000000000000297 ffff88001f7c3a00 ffffffff9efb5abe ffff88001f7c3a50 [ 21.884546] 0000000000000000 ffffffffa00f2390 ffffffff9efb8fe6 ffff88001f7c3a40 [ 21.885673] ffffffff9ece04cb 00000255a011c933 ffffffffa00f2390 0000000000000255 [ 21.899837] Call Trace: [ 21.900210] [<ffffffff9efb5abe>] dump_stack+0xb6/0x118 [ 21.900969] [<ffffffff9efb8fe6>] ? kobject_get+0xd6/0x100 [ 21.901747] [<ffffffff9ece04cb>] __warn+0x11b/0x140 [ 21.902460] [<ffffffff9ece0558>] warn_slowpath_fmt+0x68/0x80 [ 21.903282] [<ffffffff9ef40e87>] ? kernfs_put+0x37/0x240 [ 21.904054] [<ffffffff9f57a720>] ? online_show+0x60/0x60 [ 21.904818] [<ffffffff9efb8fe6>] kobject_get+0xd6/0x100 [ 21.905581] [<ffffffff9f57a720>] ? online_show+0x60/0x60 [ 21.906355] [<ffffffff9f57a749>] klist_children_get+0x29/0x40 [ 21.907191] [<ffffffff9fafe9c5>] klist_node_init+0x45/0x50 [ 21.907987] [<ffffffff9fafecfd>] klist_add_tail+0x1d/0x50 [ 21.908761] [<ffffffff9f57bb8a>] device_add+0x52a/0x780 [ 21.909526] [<ffffffff9f57bf32>] device_register+0x22/0x30 [ 21.910329] [<ffffffff9f732626>] usb_add_gadget_udc_release+0xc6/0x370 [ 21.911277] [<ffffffff9f732994>] usb_add_gadget_udc+0x24/0x30 [ 21.912117] [<ffffffff9f7361d1>] dummy_udc_probe+0x1e1/0x240 [ 21.912939] [<ffffffff9f735ff0>] ? dummy_free_request+0xc0/0xc0 [ 21.913795] [<ffffffff9f582c1e>] platform_drv_probe+0x4e/0xd0 [ 21.914625] [<ffffffff9f582bd0>] ? platform_drv_remove+0x60/0x60 [ 21.915490] [<ffffffff9f580eb2>] driver_probe_device+0xd2/0x490 [ 21.916351] [<ffffffff9f581411>] __device_attach_driver+0xb1/0xf0 [ 21.917238] [<ffffffff9f581360>] ? __driver_attach+0xf0/0xf0 [ 21.918060] [<ffffffff9f57eeb2>] bus_for_each_drv+0x92/0xe0 [ 21.918870] [<ffffffff9f580c41>] __device_attach+0xf1/0x170 [ 21.919691] [<ffffffff9f5814bf>] device_initial_probe+0x1f/0x30 [ 21.920554] [<ffffffff9f57f20e>] bus_probe_device+0xde/0xf0 [ 21.921368] [<ffffffff9f57bb6e>] device_add+0x50e/0x780 [ 21.922134] [<ffffffff9f5835d5>] platform_device_add+0xf5/0x2d0 [ 21.922990] [<ffffffffa0a96198>] init+0x328/0x49a [ 21.923674] [<ffffffffa0a95e70>] ? trace_event_define_fields_udc_log_req+0x25a/0x25a [ 21.924782] [<ffffffffa0a4041c>] do_one_initcall+0xa5/0x191 [ 21.925597] [<ffffffffa0a4072d>] kernel_init_freeable+0x225/0x2cd [ 21.926483] [<ffffffff9faffe98>] kernel_init+0x18/0x180 [ 21.927243] [<ffffffff9fb1034f>] ret_from_fork+0x1f/0x40 [ 21.928015] [<ffffffff9faffe80>] ? rest_init+0xd0/0xd0 [ 21.929031] ---[ end trace def35186a836ffe3 ]--- [ 65.318331] Writes: Total: 2 Max/Min: 0/0 Fail: 0 git bisect start v4.9 v4.8 -- git bisect bad 9fe68cad6e74967b88d0c6aeca7d9cd6b6e91942 # 01:19 7- 11 Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 git bisect bad 5fa0eb0b4d4780fbd6d8a09850cc4fd539e9fe65 # 01:37 0- 1 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip git bisect bad d8ea757b25ec82687c497fc90aa83f9bcea24b5b # 01:50 0- 1 Merge tag 'xtensa-20161005' of git://github.com/jcmvbkbc/linux-xtensa git bisect bad e6445f52d9c8b0e6557a45fa7d0e8e088d430a8c # 02:01 1- 2 Merge tag 'usb-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb git bisect good 1a4a2bc460721bc8f91e4c1294d39b38e5af132f # 03:16 50+ 0 Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip git bisect good 49deffe0b0e4c2030696c7a6fd680bacf4761069 # 03:40 54+ 0 Merge tag 'arc-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc git bisect good 597f03f9d133e9837d00965016170271d4f87dcf # 04:19 53+ 0 Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip git bisect bad 9929780e86854833e649b39b290b5fe921eb1701 # 04:47 2- 2 Merge tag 'driver-core-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core git bisect good 7a53eea1f7b527fd3b6d7ca992914840981afe99 # 07:37 51+ 1 Merge tag 'char-misc-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc git bisect bad 775115c06091fcfa1189a50aca488fa596839617 # 07:49 8- 3 drivers/base dmam_declare_coherent_memory leaks git bisect bad 426bc8e789f8ac84270b196191904d347586032f # 08:08 1- 1 base: soc: make it explicitly non-modular git bisect bad bea5b158ff0da9c7246ff391f754f5f38e34577a # 08:30 3- 2 driver core: add test of driver remove calls during probe git bisect good cebf8fd16900fdfd58c0028617944f808f97fe50 # 11:35 100+ 1 driver core: fix race between creating/querying glue dir and its cleanup # first bad commit: [bea5b158ff0da9c7246ff391f754f5f38e34577a] driver core: add test of driver remove calls during probe git bisect good cebf8fd16900fdfd58c0028617944f808f97fe50 # 14:28 306+ 4 driver core: fix race between creating/querying glue dir and its cleanup # extra tests with CONFIG_DEBUG_INFO_REDUCED git bisect bad bea5b158ff0da9c7246ff391f754f5f38e34577a # 14:44 13- 7 driver core: add test of driver remove calls during probe # extra tests on HEAD of linux-devel/devel-spot-201612242150 git bisect bad 5cc3c0a7bfc339d9960e6c946a678d179a2aa03c # 14:44 0- 12 0day head guard for 'devel-spot-201612242150' # extra tests on tree/branch linus/master git bisect bad 7c0f6ba682b9c7632072ffbedf8d328c8f3c42ba # 14:55 3- 4 Replace <asm/uaccess.h> with <linux/uaccess.h> globally # extra tests on tree/branch linus/master git bisect bad 7c0f6ba682b9c7632072ffbedf8d328c8f3c42ba # 14:55 0- 4 Replace <asm/uaccess.h> with <linux/uaccess.h> globally # extra tests on tree/branch linux-next/master git bisect bad 84ede50b623fb45c4c026c80d0abf8cc5193f041 # 15:12 1- 1 Add linux-next specific files for 20161224 --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/lkp Intel Corporation