linux/drivers/base, branch v3.4.96

drivercore: deferral race condition fix

2014-06-07T23:02:01Z

commit 58b116bce13612e5aa6fcd49ecbd4cf8bb59e835 upstream. When the kernel is built with CONFIG_PREEMPT it is possible to reach a state when all modules loaded but some driver still stuck in the deferred list and there is a need for external event to kick the deferred queue to probe these drivers. The issue has been observed on embedded systems with CONFIG_PREEMPT enabled, audio support built as modules and using nfsroot for root filesystem. The following log fragment shows such sequence when all audio modules were loaded but the sound card is not present since the machine driver has failed to probe due to missing dependency during it's probe. The board is am335x-evmsk (McASP<->tlv320aic3106 codec) with davinci-evm machine driver: ... [ 12.615118] davinci-mcasp 4803c000.mcasp: davinci_mcasp_probe: ENTER [ 12.719969] davinci_evm sound.3: davinci_evm_probe: ENTER [ 12.725753] davinci_evm sound.3: davinci_evm_probe: snd_soc_register_card [ 12.753846] davinci-mcasp 4803c000.mcasp: davinci_mcasp_probe: snd_soc_register_component [ 12.922051] davinci-mcasp 4803c000.mcasp: davinci_mcasp_probe: snd_soc_register_component DONE [ 12.950839] davinci_evm sound.3: ASoC: platform (null) not registered [ 12.957898] davinci_evm sound.3: davinci_evm_probe: snd_soc_register_card DONE (-517) [ 13.099026] davinci-mcasp 4803c000.mcasp: Kicking the deferred list [ 13.177838] davinci-mcasp 4803c000.mcasp: really_probe: probe_count = 2 [ 13.194130] davinci_evm sound.3: snd_soc_register_card failed (-517) [ 13.346755] davinci_mcasp_driver_init: LEAVE [ 13.377446] platform sound.3: Driver davinci_evm requests probe deferral [ 13.592527] platform sound.3: really_probe: probe_count = 0 In the log the machine driver enters it's probe at 12.719969 (this point it has been removed from the deferred lists). McASP driver already executing it's probing (since 12.615118). The machine driver tries to construct the sound card (12.950839) but did not found one of the components so it fails. After this McASP driver registers all the ASoC components (the machine driver still in it's probe function after it failed to construct the card) and the deferred work is prepared at 13.099026 (note that this time the machine driver is not in the lists so it is not going to be handled when the work is executing). Lastly the machine driver exit from it's probe and the core places it to the deferred list but there will be no other driver going to load and the deferred queue is not going to be kicked again - till we have external event like connecting USB stick, etc. The proposed solution is to try the deferred queue once more when the last driver is asking for deferring and we had drivers loaded while this last driver was probing. This way we can avoid drivers stuck in the deferred queue. Signed-off-by: Grant Likely Reviewed-by: Peter Ujfalusi Tested-by: Peter Ujfalusi Acked-by: Greg Kroah-Hartman Cc: Mark Brown Signed-off-by: Greg Kroah-Hartman

drivers/base/memory.c: fix show_mem_removable() to handle missing sections

2013-09-08T04:58:14Z

commit 21ea9f5ace3a7317cc3ba1fbc749758021a83136 upstream. "cat /sys/devices/system/memory/memory*/removable" crashed the system. The problem is that show_mem_removable() is passing a bad pfn to is_mem_section_removable(), which causes if (!node_online(page_to_nid(page))) to blow up. Why is it passing in a bad pfn? The reason is that show_mem_removable() will loop sections_per_block times. sections_per_block is 16, but mem->section_count is 8, indicating holes in this memory block. Checking that the memory section is present before checking to see if the memory section is removable fixes the problem. harp5-sys:~ # cat /sys/devices/system/memory/memory*/removable 0 1 1 1 1 1 1 1 1 1 1 1 1 1 BUG: unable to handle kernel paging request at ffffea00c3200000 IP: [] is_pageblock_removable_nolock+0x1/0x90 PGD 83ffd4067 PUD 37bdfce067 PMD 0 Oops: 0000 [#1] SMP Modules linked in: autofs4 binfmt_misc rdma_ucm rdma_cm iw_cm ib_addr ib_srp scsi_transport_srp scsi_tgt ib_ipoib ib_cm ib_uverbs ib_umad iw_cxgb3 cxgb3 mdio mlx4_en mlx4_ib ib_sa mlx4_core ib_mthca ib_mad ib_core fuse nls_iso8859_1 nls_cp437 vfat fat joydev loop hid_generic usbhid hid hwperf(O) numatools(O) dm_mod iTCO_wdt ipv6 iTCO_vendor_support igb i2c_i801 ioatdma i2c_algo_bit ehci_pci pcspkr lpc_ich i2c_core ehci_hcd ptp sg mfd_core dca rtc_cmos pps_core mperf button xhci_hcd sd_mod crc_t10dif usbcore usb_common scsi_dh_emc scsi_dh_hp_sw scsi_dh_alua scsi_dh_rdac scsi_dh gru(O) xvma(O) xfs crc32c libcrc32c thermal sata_nv processor piix mptsas mptscsih scsi_transport_sas mptbase megaraid_sas fan thermal_sys hwmon ext3 jbd ata_piix ahci libahci libata scsi_mod CPU: 4 PID: 5991 Comm: cat Tainted: G O 3.11.0-rc5-rja-uv+ #10 Hardware name: SGI UV2000/ROMLEY, BIOS SGI UV 2000/3000 series BIOS 01/15/2013 task: ffff88081f034580 ti: ffff880820022000 task.ti: ffff880820022000 RIP: 0010:[] [] is_pageblock_removable_nolock+0x1/0x90 RSP: 0018:ffff880820023df8 EFLAGS: 00010287 RAX: 0000000000040000 RBX: ffffea00c3200000 RCX: 0000000000000004 RDX: ffffea00c30b0000 RSI: 00000000001c0000 RDI: ffffea00c3200000 RBP: ffff880820023e38 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000001 R12: ffffea00c33c0000 R13: 0000160000000000 R14: 6db6db6db6db6db7 R15: 0000000000000001 FS: 00007ffff7fb2700(0000) GS:ffff88083fc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffea00c3200000 CR3: 000000081b954000 CR4: 00000000000407e0 Call Trace: show_mem_removable+0x41/0x70 dev_attr_show+0x2a/0x60 sysfs_read_file+0xf7/0x1c0 vfs_read+0xc8/0x130 SyS_read+0x5d/0xa0 system_call_fastpath+0x16/0x1b Signed-off-by: Russ Anderson Cc: "Rafael J. Wysocki" Cc: Yinghai Lu Reviewed-by: Yasuaki Ishimatsu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

regmap: silence GCC warning

2013-09-08T04:58:14Z

commit a8f28cfad8cd44d7c34b166d0e5ace1125dbee1f upstream. Building regmap.o triggers this GCC warning: drivers/base/regmap/regmap.c: In function ‘regmap_raw_read’: drivers/base/regmap/regmap.c:1172:6: warning: ‘ret’ may be used uninitialized in this function [-Wmaybe-uninitialized] Long story short: Jakub Jelinek pointed out that there is a type mismatch between 'num' in regmap_volatile_range() and 'val_count' in regmap_raw_read(). And indeed, converting 'num' to the type of 'val_count' (ie, size_t) makes this warning go away. Signed-off-by: Paul Bolle Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman

regmap: cache Fix regcache-rbtree sync

2013-04-12T16:38:43Z

commit 8abac3ba51b5525354e9b2ec0eed1c9e95c905d9 upstream. The last register block, which falls into the specified range, is not handled correctly. The formula which calculates the number of register which should be synced is inverse (and off by one). E.g. if all registers in that block should be synced only one is synced, and if only one should be synced all (but one) are synced. To calculate the number of registers that need to be synced we need to subtract the number of the first register in the block from the max register number and add one. This patch updates the code accordingly. The issue was introduced in commit ac8d91c ("regmap: Supply ranges to the sync operations"). Signed-off-by: Lars-Peter Clausen Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman

drivercore: Fix ordering between deferred_probe and exiting initcalls

2013-02-28T14:59:01Z

commit d72cca1eee5b26e313da2a380d4862924e271031 upstream. One of the side effects of deferred probe is that some drivers which used to be probed before initcalls completed are now happening slightly later. This causes two problems. - If a console driver gets deferred, then it may not be ready when userspace starts. For example, if a uart depends on pinctrl, then the uart will get deferred and /dev/console will not be available - __init sections will be discarded before built-in drivers are probed. Strictly speaking, __init functions should not be called in a drivers __probe path, but there are a lot of drivers (console stuff again) that do anyway. In the past it was perfectly safe to do so because all built-in drivers got probed before the end of initcalls. This patch fixes the problem by forcing the first pass of the deferred list to complete at late_initcall time. This is late enough to catch the drivers that are known to have the above issues. Signed-off-by: Grant Likely Tested-by: Haojian Zhuang Cc: Arnd Bergmann Cc: Russell King Cc: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

Driver core: treat unregistered bus_types as having no devices

2013-02-28T14:59:00Z

commit 4fa3e78be7e985ca814ce2aa0c09cbee404efcf7 upstream. A bus_type has a list of devices (klist_devices), but the list and the subsys_private structure that contains it are not initialized until the bus_type is registered with bus_register(). The panic/reboot path has fixups that look up devices in pci_bus_type. If we panic before registering pci_bus_type, the bus_type exists but the list does not, so mach_reboot_fixups() trips over a null pointer and panics again: mach_reboot_fixups pci_get_device .. bus_find_device(&pci_bus_type, ...) bus->p is NULL Joonsoo reported a problem when panicking before PCI was initialized. I think this patch should be sufficient to replace the patch he posted here: https://lkml.org/lkml/2012/12/28/75 ("[PATCH] x86, reboot: skip reboot_fixups in early boot phase") Reported-by: Joonsoo Kim Signed-off-by: Bjorn Helgaas Signed-off-by: Greg Kroah-Hartman

regmap: debugfs: Avoid overflows for very small reads

2013-01-17T16:50:54Z

commit db04328c167ff8e7c57f4a3532214aeada3a82fd upstream. If count is less than the size of a register then we may hit integer wraparound when trying to move backwards to check if we're still in the buffer. Instead move the position forwards to check if it's still in the buffer, we are unlikely to be able to allocate a buffer sufficiently big to overflow here. Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman

PM / QoS: fix wrong error-checking condition

2012-12-03T19:47:10Z

commit a7227a0faa117d0bc532aea546ae5ac5f89e8ed7 upstream. dev_pm_qos_add_request() can return 0, 1, or a negative error code, therefore the correct error test is "if (error < 0)." Checking just for non-zero return code leads to erroneous setting of the req->dev pointer to NULL, which then leads to a repeated call to dev_pm_qos_add_ancestor_request() in st1232_ts_irq_handler(). This in turn leads to an Oops, when the I2C host adapter is unloaded and reloaded again because of the inconsistent state of its QoS request list. Signed-off-by: Guennadi Liakhovetski Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

PM / Sleep: use resume event when call dpm_resume_early

2012-10-12T20:38:39Z

commit 997a031107ec962967ce36db9bc500f1fad491c1 upstream. When dpm_suspend_noirq fail, state is PMSG_SUSPEND, should change to PMSG_RESUME when dpm_resume_early is called Signed-off-by: Feng Hong Signed-off-by: Raul Xiong Signed-off-by: Neil Zhang Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

PM / Runtime: Clear power.deferred_resume on success in rpm_suspend()

2012-10-02T17:30:22Z

commit 58a34de7b1a920d287d17d2ca08bc9aaf7e6d35b upstream. The power.deferred_resume can only be set if the runtime PM status of device is RPM_SUSPENDING and it should be cleared after its status has been changed, regardless of whether or not the runtime suspend has been successful. However, it only is cleared on suspend failure, while it may remain set on successful suspend and is happily leaked to rpm_resume() executed in that case. That shouldn't happen, so if power.deferred_resume is set in rpm_suspend() after the status has been changed to RPM_SUSPENDED, clear it before calling rpm_resume(). Then, it doesn't need to be cleared before changing the status to RPM_SUSPENDING any more, because it's always cleared after the status has been changed to either RPM_SUSPENDED (on success) or RPM_ACTIVE (on failure). Signed-off-by: Rafael J. Wysocki Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman