kernel/linux.git/drivers/base/dd.c, branch v4.14.263

PM: runtime: Resume the device earlier in __device_release_driver()

2020-11-10T09:29:07+00:00

commit 9226c504e364158a17a68ff1fe9d67d266922f50 upstream. Since the device is resumed from runtime-suspend in __device_release_driver() anyway, it is better to do that before looking for busy managed device links from it to consumers, because if there are any, device_links_unbind_consumers() will be called and it will cause the consumer devices' drivers to unbind, so the consumer devices will be runtime-resumed. In turn, resuming each consumer device will cause the supplier to be resumed and when the runtime PM references from the given consumer to it are dropped, it may be suspended. Then, the runtime-resume of the next consumer will cause the supplier to resume again and so on. Update the code accordingly. Signed-off-by: Rafael J. Wysocki Fixes: 9ed9895370ae ("driver core: Functional dependencies tracking support") Cc: All applicable # All applicable Tested-by: Xiang Chen Reviewed-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman

driver core: Fix probe_count imbalance in really_probe()

2020-10-14T07:51:11+00:00

commit b292b50b0efcc7095d8bf15505fba6909bb35dce upstream. syzbot is reporting hung task in wait_for_device_probe() [1]. At least, we always need to decrement probe_count if we incremented probe_count in really_probe(). However, since I can't find "Resources present before probing" message in the console log, both "this message simply flowed off" and "syzbot is not hitting this path" will be possible. Therefore, while we are at it, let's also prepare for concurrent wait_for_device_probe() calls by replacing wake_up() with wake_up_all(). [1] https://syzkaller.appspot.com/bug?id=25c833f1983c9c1d512f4ff860dd0d7f5a2e2c0f Reported-by: syzbot Fixes: 7c35e699c88bd607 ("driver core: Print device when resources present in really_probe()") Cc: Geert Uytterhoeven Signed-off-by: Tetsuo Handa Cc: stable Link: https://lore.kernel.org/r/20200713021254.3444-1-penguin-kernel@I-love.SAKURA.ne.jp [iwamatsu: Drop patch for deferred_probe_timeout_work_func()] Signed-off-by: Nobuhiro Iwamatsu (CIP) Signed-off-by: Greg Kroah-Hartman

driver core: Print device when resources present in really_probe()

2020-02-28T15:36:04+00:00

[ Upstream commit 7c35e699c88bd60734277b26962783c60e04b494 ] If a device already has devres items attached before probing, a warning backtrace is printed. However, this backtrace does not reveal the offending device, leaving the user uninformed. Furthermore, using WARN_ON() causes systems with panic-on-warn to reboot. Fix this by replacing the WARN_ON() by a dev_crit() message. Abort probing the device, to prevent doing more damage to the device's resources. Signed-off-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/20191206132219.28908-1-geert+renesas@glider.be Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

driver core: Postpone DMA tear-down until after devres release for probe failure

2019-05-25T16:25:37+00:00

commit 0b777eee88d712256ba8232a9429edb17c4f9ceb upstream. In commit 376991db4b64 ("driver core: Postpone DMA tear-down until after devres release"), we changed the ordering of tearing down the device DMA ops and releasing all the device's resources; this was because the DMA ops should be maintained until we release the device's managed DMA memories. However, we have seen another crash on an arm64 system when a device driver probe fails: hisi_sas_v3_hw 0000:74:02.0: Adding to iommu group 2 scsi host1: hisi_sas_v3_hw BUG: Bad page state in process swapper/0 pfn:313f5 page:ffff7e0000c4fd40 count:1 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0xfffe00000001000(reserved) raw: 0fffe00000001000 ffff7e0000c4fd48 ffff7e0000c4fd48 0000000000000000 raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000 page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set bad because of flags: 0x1000(reserved) Modules linked in: CPU: 49 PID: 1 Comm: swapper/0 Not tainted 5.1.0-rc1-43081-g22d97fd-dirty #1433 Hardware name: Huawei D06/D06, BIOS Hisilicon D06 UEFI RC0 - V1.12.01 01/29/2019 Call trace: dump_backtrace+0x0/0x118 show_stack+0x14/0x1c dump_stack+0xa4/0xc8 bad_page+0xe4/0x13c free_pages_check_bad+0x4c/0xc0 __free_pages_ok+0x30c/0x340 __free_pages+0x30/0x44 __dma_direct_free_pages+0x30/0x38 dma_direct_free+0x24/0x38 dma_free_attrs+0x9c/0xd8 dmam_release+0x20/0x28 release_nodes+0x17c/0x220 devres_release_all+0x34/0x54 really_probe+0xc4/0x2c8 driver_probe_device+0x58/0xfc device_driver_attach+0x68/0x70 __driver_attach+0x94/0xdc bus_for_each_dev+0x5c/0xb4 driver_attach+0x20/0x28 bus_add_driver+0x14c/0x200 driver_register+0x6c/0x124 __pci_register_driver+0x48/0x50 sas_v3_pci_driver_init+0x20/0x28 do_one_initcall+0x40/0x25c kernel_init_freeable+0x2b8/0x3c0 kernel_init+0x10/0x100 ret_from_fork+0x10/0x18 Disabling lock debugging due to kernel taint BUG: Bad page state in process swapper/0 pfn:313f6 page:ffff7e0000c4fd80 count:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 89.322983] flags: 0xfffe00000001000(reserved) raw: 0fffe00000001000 ffff7e0000c4fd88 ffff7e0000c4fd88 0000000000000000 raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000 The crash occurs for the same reason. In this case, on the really_probe() failure path, we are still clearing the DMA ops prior to releasing the device's managed memories. This patch fixes this issue by reordering the DMA ops teardown and the call to devres_release_all() on the failure path. Reported-by: Xiang Chen Tested-by: Xiang Chen Signed-off-by: John Garry Reviewed-by: Robin Murphy [jpg: backport to 4.19.x and earlier] Signed-off-by: John Garry Signed-off-by: Greg Kroah-Hartman

driver core: Postpone DMA tear-down until after devres release

2019-03-13T21:03:23+00:00

commit 376991db4b6464e906d699ef07681e2ffa8ab08c upstream. When unbinding the (IOMMU-enabled) R-Car SATA device on Salvator-XS (R-Car H3 ES2.0), in preparation of rebinding against vfio-platform for device pass-through for virtualization: echo ee300000.sata > /sys/bus/platform/drivers/sata_rcar/unbind the kernel crashes with: Unable to handle kernel paging request at virtual address ffffffbf029ffffc Mem abort info: ESR = 0x96000006 Exception class = DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000006 CM = 0, WnR = 0 swapper pgtable: 4k pages, 39-bit VAs, pgdp = 000000007e8c586c [ffffffbf029ffffc] pgd=000000073bfc6003, pud=000000073bfc6003, pmd=0000000000000000 Internal error: Oops: 96000006 [#1] SMP Modules linked in: CPU: 0 PID: 1098 Comm: bash Not tainted 5.0.0-rc5-salvator-x-00452-g37596f884f4318ef #287 Hardware name: Renesas Salvator-X 2nd version board based on r8a7795 ES2.0+ (DT) pstate: 60400005 (nZCv daif +PAN -UAO) pc : __free_pages+0x8/0x58 lr : __dma_direct_free_pages+0x50/0x5c sp : ffffff801268baa0 x29: ffffff801268baa0 x28: 0000000000000000 x27: ffffffc6f9c60bf0 x26: ffffffc6f9c60bf0 x25: ffffffc6f9c60810 x24: 0000000000000000 x23: 00000000fffff000 x22: ffffff8012145000 x21: 0000000000000800 x20: ffffffbf029fffc8 x19: 0000000000000000 x18: ffffffc6f86c42c8 x17: 0000000000000000 x16: 0000000000000070 x15: 0000000000000003 x14: 0000000000000000 x13: ffffff801103d7f8 x12: 0000000000000028 x11: ffffff8011117604 x10: 0000000000009ad8 x9 : ffffff80110126d0 x8 : ffffffc6f7563000 x7 : 6b6b6b6b6b6b6b6b x6 : 0000000000000018 x5 : ffffff8011cf3cc8 x4 : 0000000000004000 x3 : 0000000000080000 x2 : 0000000000000001 x1 : 0000000000000000 x0 : ffffffbf029fffc8 Process bash (pid: 1098, stack limit = 0x00000000c38e3e32) Call trace: __free_pages+0x8/0x58 __dma_direct_free_pages+0x50/0x5c arch_dma_free+0x1c/0x98 dma_direct_free+0x14/0x24 dma_free_attrs+0x9c/0xdc dmam_release+0x18/0x20 release_nodes+0x25c/0x28c devres_release_all+0x48/0x4c device_release_driver_internal+0x184/0x1f0 device_release_driver+0x14/0x1c unbind_store+0x70/0xb8 drv_attr_store+0x24/0x34 sysfs_kf_write+0x4c/0x64 kernfs_fop_write+0x154/0x1c4 __vfs_write+0x34/0x164 vfs_write+0xb4/0x16c ksys_write+0x5c/0xbc __arm64_sys_write+0x14/0x1c el0_svc_common+0x98/0x114 el0_svc_handler+0x1c/0x24 el0_svc+0x8/0xc Code: d51b4234 17fffffa a9bf7bfd 910003fd (b9403404) ---[ end trace 8c564cdd3a1a840f ]--- While I've bisected this to commit e8e683ae9a736407 ("iommu/of: Fix probe-deferral"), and reverting that commit on post-v5.0-rc4 kernels does fix the problem, this turned out to be a red herring. On arm64, arch_teardown_dma_ops() resets dev->dma_ops to NULL. Hence if a driver has used a managed DMA allocation API, the allocated DMA memory will be freed using the direct DMA ops, while it may have been allocated using a custom DMA ops (iommu_dma_ops in this case). Fix this by reversing the order of the calls to devres_release_all() and arch_teardown_dma_ops(). Signed-off-by: Geert Uytterhoeven Acked-by: Christoph Hellwig Reviewed-by: Rafael J. Wysocki Cc: stable Reviewed-by: Robin Murphy [rm: backport for 4.12-4.19 - kernels before 5.0 will not see the crash above, but may get silent memory corruption instead] Signed-off-by: Robin Murphy Signed-off-by: Greg Kroah-Hartman

driver core: Move async_synchronize_full call

2019-02-12T18:46:02+00:00

[ Upstream commit c37d721c68ad88925ba0e72f6e14acb829a8c6bb ] Move the async_synchronize_full call out of __device_release_driver and into driver_detach. The idea behind this is that the async_synchronize_full call will only guarantee that any existing async operations are flushed. This doesn't do anything to guarantee that a hotplug event that may occur while we are doing the release of the driver will not be asynchronously scheduled. By moving this into the driver_detach path we can avoid potential deadlocks as we aren't holding the device lock at this point and we should not have the driver we want to flush loaded so the flush will take care of any asynchronous events the driver we are detaching might have scheduled. Fixes: 765230b5f084 ("driver-core: add asynchronous probing support for drivers") Reviewed-by: Bart Van Assche Reviewed-by: Dan Williams Signed-off-by: Alexander Duyck Reviewed-by: Luis Chamberlain Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

driver core: Partially revert "driver core: correct device's shutdown order"

2018-07-28T05:55:44+00:00

commit 722e5f2b1eec7de61117b7c0a7914761e3da2eda upstream. Commit 52cdbdd49853 (driver core: correct device's shutdown order) introduced a regression by breaking device shutdown on some systems. Namely, the devices_kset_move_last() call in really_probe() added by that commit is a mistake as it may cause parents to follow children in the devices_kset list which then causes shutdown to fail. For example, if a device has children before really_probe() is called for it (which is not uncommon), that call will cause it to be reordered after the children in the devices_kset list and the ordering of that list will not reflect the correct device shutdown order any more. Also it causes the devices_kset list to be constantly reordered until all drivers have been probed which is totally pointless overhead in the majority of cases and it only covered an issue with system shutdown, while system-wide suspend/resume potentially had the same issue on the affected platforms (which was not covered). Moreover, the shutdown issue originally addressed by the change in really_probe() made by commit 52cdbdd49853 is not present in 4.18-rc any more, since dra7 started to use the sdhci-omap driver which doesn't disable any regulators during shutdown, so the really_probe() part of commit 52cdbdd49853 can be safely reverted. [The original issue was related to the omap_hsmmc driver used by dra7 previously.] For the above reasons, revert the really_probe() modifications made by commit 52cdbdd49853. The other code changes made by commit 52cdbdd49853 are useful and they need not be reverted. Fixes: 52cdbdd49853 (driver core: correct device's shutdown order) Link: https://lore.kernel.org/lkml/CAFgQCTt7VfqM=UyCnvNFxrSw8Z6cUtAi3HUwR4_xPAc03SgHjQ@mail.gmail.com/ Reported-by: Pingfan Liu Tested-by: Pingfan Liu Reviewed-by: Kishon Vijay Abraham I Signed-off-by: Rafael J. Wysocki Cc: stable Signed-off-by: Greg Kroah-Hartman

initcall_debug: add deferred probe times

2017-08-04T00:48:49+00:00

initcall_debug attributes all deferred device probe retries for the late_initcall level to function deferred_probe_initcall. Add logs of the individual device probe routines called, to identify which drivers are executing for how long during the initcall path. Deferred probes that occur after initcall processing are not shown. Example log messages added: [ 0.505119] deferred probe my-sound-device @ 6 [ 0.517656] deferred probe my-sound-device returned after 1227 usecs Signed-off-by: Todd Poynor Signed-off-by: Greg Kroah-Hartman

driver core: emit uevents when device is bound to a driver

2017-07-22T09:59:23+00:00

There are certain touch controllers that may come up in either normal (application) or boot mode, depending on whether firmware/configuration is corrupted when they are powered on. In boot mode the kernel does not create input device instance (because it does not necessarily know the characteristics of the input device in question). Another number of controllers does not store firmware in a non-volatile memory, and they similarly need to have firmware loaded before input device instance is created. There are also other types of devices with similar behavior. There is a desire to be able to trigger firmware loading via udev, but it has to happen only when driver is bound to a physical device (i2c or spi). These udev actions can not use ADD events, as those happen too early, so we are introducing BIND and UNBIND events that are emitted at the right moment. Also, many drivers create additional driver-specific device attributes when binding to the device, to provide userspace with additional controls. The new events allow userspace to adjust these driver-specific attributes without worrying that they are not there yet. Signed-off-by: Dmitry Torokhov Signed-off-by: Greg Kroah-Hartman

of/acpi: Configure dma operations at probe time for platform/amba/pci bus devices

2017-04-20T14:31:06+00:00

Configuring DMA ops at probe time will allow deferring device probe when the IOMMU isn't available yet. The dma_configure for the device is now called from the generic device_attach callback just before the bus/driver probe is called. This way, configuring the DMA ops for the device would be called at the same place for all bus_types, hence the deferred probing mechanism should work for all buses as well. pci_bus_add_devices (platform/amba)(_device_create/driver_register) | | pci_bus_add_device (device_add/driver_register) | | device_attach device_initial_probe | | __device_attach_driver __device_attach_driver | driver_probe_device | really_probe | dma_configure Similarly on the device/driver_unregister path __device_release_driver is called which inturn calls dma_deconfigure. This patch changes the dma ops configuration to probe time for both OF and ACPI based platform/amba/pci bus devices. Tested-by: Marek Szyprowski Tested-by: Hanjun Guo Reviewed-by: Robin Murphy Acked-by: Rob Herring Acked-by: Bjorn Helgaas (drivers/pci part) Acked-by: Rafael J. Wysocki Signed-off-by: Sricharan R Signed-off-by: Joerg Roedel