linux/drivers/base/memory.c, branch v3.12.14

driver core: Release device_hotplug_lock when store_mem_state returns EINVAL

2013-10-17T01:42:41Z

When inserting a wrong value to /sys/devices/system/memory/memoryX/state file, following messages are shown. And device_hotplug_lock is never released. ================================================ [ BUG: lock held when returning to user space! ] 3.12.0-rc4-debug+ #3 Tainted: G W ------------------------------------------------ bash/6442 is leaving the kernel with locks still held! 1 lock held by bash/6442: #0: (device_hotplug_lock){+.+.+.}, at: [] lock_device_hotplug_sysfs+0x15/0x50 This issue was introdued by commit fa2be40 (drivers: base: use standard device online/offline for state change). This patch releases device_hotplug_lcok when store_mem_state returns EINVAL. Signed-off-by: Yasuaki Ishimatsu Reviewed-by: Toshi Kani CC: Seth Jennings Signed-off-by: Greg Kroah-Hartman

Merge tag 'pm+acpi-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2013-09-03T22:59:39Z

Pull ACPI and power management updates from Rafael Wysocki: 1) ACPI-based PCI hotplug (ACPIPHP) subsystem rework and introduction of Intel Thunderbolt support on systems that use ACPI for signalling Thunderbolt hotplug events. This also should make ACPIPHP work in some cases in which it was known to have problems. From Rafael J Wysocki, Mika Westerberg and Kirill A Shutemov. 2) ACPI core code cleanups and dock station support cleanups from Jiang Liu and Rafael J Wysocki. 3) Fixes for locking problems related to ACPI device hotplug from Rafael J Wysocki. 4) ACPICA update to version 20130725 includig fixes, cleanups, support for more than 256 GPEs per GPE block and a change to make the ACPI PM Timer optional (we've seen systems without the PM Timer in the field already). One of the fixes, related to the DeRefOf operator, is necessary to prevent some Windows 8 oriented AML from causing problems to happen. From Bob Moore, Lv Zheng, and Jung-uk Kim. 5) Removal of the old and long deprecated /proc/acpi/event interface and related driver changes from Thomas Renninger. 6) ACPI and Xen changes to make the reduced hardware sleep work with the latter from Ben Guthro. 7) ACPI video driver cleanups and a blacklist of systems that should not tell the BIOS that they are compatible with Windows 8 (or ACPI backlight and possibly other things will not work on them). From Felipe Contreras. 8) Assorted ACPI fixes and cleanups from Aaron Lu, Hanjun Guo, Kuppuswamy Sathyanarayanan, Lan Tianyu, Sachin Kamat, Tang Chen, Toshi Kani, and Wei Yongjun. 9) cpufreq ondemand governor target frequency selection change to reduce oscillations between min and max frequencies (essentially, it causes the governor to choose target frequencies proportional to load) from Stratos Karafotis. 10) cpufreq fixes allowing sysfs attributes file permissions to be preserved over suspend/resume cycles Srivatsa S Bhat. 11) Removal of Device Tree parsing for CPU device nodes from multiple cpufreq drivers that required some changes related to of_get_cpu_node() to be made in a few architectures and in the driver core. From Sudeep KarkadaNagesha. 12) cpufreq core fixes and cleanups related to mutual exclusion and driver module references from Viresh Kumar, Lukasz Majewski and Rafael J Wysocki. 13) Assorted cpufreq fixes and cleanups from Amit Daniel Kachhap, Bartlomiej Zolnierkiewicz, Hanjun Guo, Jingoo Han, Joseph Lo, Julia Lawall, Li Zhong, Mark Brown, Sascha Hauer, Stephen Boyd, Stratos Karafotis, and Viresh Kumar. 14) Fixes to prevent race conditions in coupled cpuidle from happening from Colin Cross. 15) cpuidle core fixes and cleanups from Daniel Lezcano and Tuukka Tikkanen. 16) Assorted cpuidle fixes and cleanups from Daniel Lezcano, Geert Uytterhoeven, Jingoo Han, Julia Lawall, Linus Walleij, and Sahara. 17) System sleep tracing changes from Todd E Brandt and Shuah Khan. 18) PNP subsystem conversion to using struct dev_pm_ops for power management from Shuah Khan. * tag 'pm+acpi-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (217 commits) cpufreq: Don't use smp_processor_id() in preemptible context cpuidle: coupled: fix race condition between pokes and safe state cpuidle: coupled: abort idle if pokes are pending cpuidle: coupled: disable interrupts after entering safe state ACPI / hotplug: Remove containers synchronously driver core / ACPI: Avoid device hot remove locking issues cpufreq: governor: Fix typos in comments cpufreq: governors: Remove duplicate check of target freq in supported range cpufreq: Fix timer/workqueue corruption due to double queueing ACPI / EC: Add ASUSTEK L4R to quirk list in order to validate ECDT ACPI / thermal: Add check of "_TZD" availability and evaluating result cpufreq: imx6q: Fix clock enable balance ACPI: blacklist win8 OSI for buggy laptops cpufreq: tegra: fix the wrong clock name cpuidle: Change struct menu_device field types cpuidle: Add a comment warning about possible overflow cpuidle: Fix variable domains in get_typical_interval() cpuidle: Fix menu_device->intervals type cpuidle: CodingStyle: Break up multiple assignments on single line cpuidle: Check called function parameter in get_typical_interval() ...

Merge tag 'driver-core-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

2013-09-03T18:37:15Z

Pull driver core patches from Greg KH: "Here's the big driver core pull request for 3.12-rc1. Lots of tiny changes here fixing up the way sysfs attributes are created, to try to make drivers simpler, and fix a whole class race conditions with creations of device attributes after the device was announced to userspace. All the various pieces are acked by the different subsystem maintainers" * tag 'driver-core-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (119 commits) firmware loader: fix pending_fw_head list corruption drivers/base/memory.c: introduce help macro to_memory_block dynamic debug: line queries failing due to uninitialized local variable sysfs: sysfs_create_groups returns a value. debugfs: provide debugfs_create_x64() when disabled rbd: convert bus code to use bus_groups firmware: dcdbas: use binary attribute groups sysfs: add sysfs_create/remove_groups for when SYSFS is not enabled driver core: add #include to core files. HID: convert bus code to use dev_groups Input: serio: convert bus code to use drv_groups Input: gameport: convert bus code to use drv_groups driver core: firmware: use __ATTR_RW() driver core: core: use DEVICE_ATTR_RO driver core: bus: use DRIVER_ATTR_WO() driver core: create write-only attribute macros for devices and drivers sysfs: create __ATTR_WO() driver-core: platform: convert bus code to use dev_groups workqueue: convert bus code to use dev_groups MEI: convert bus code to use dev_groups ...

driver core / ACPI: Avoid device hot remove locking issues

2013-08-29T20:00:53Z

device_hotplug_lock is held around the acpi_bus_trim() call in acpi_scan_hot_remove() which generally removes devices (it removes ACPI device objects at least, but it may also remove "physical" device objects through .detach() callbacks of ACPI scan handlers). Thus, potentially, device sysfs attributes are removed under that lock and to remove those attributes it is necessary to hold the s_active references of their directory entries for writing. On the other hand, the execution of a .show() or .store() callback from a sysfs attribute is carried out with that attribute's s_active reference held for reading. Consequently, if any device sysfs attribute that may be removed from within acpi_scan_hot_remove() through acpi_bus_trim() has a .store() or .show() callback which acquires device_hotplug_lock, the execution of that callback may deadlock with the removal of the attribute. [Unfortunately, the "online" device attribute of CPUs and memory blocks is one of them.] To avoid such deadlocks, make all of the sysfs attribute callbacks that need to lock device hotplug, for example store_online(), use a special function, lock_device_hotplug_sysfs(), to lock device hotplug and return the result of that function immediately if it is not zero. This will cause the s_active reference of the directory entry in question to be released and the syscall to be restarted if device_hotplug_lock cannot be acquired. [show_online() actually doesn't need to lock device hotplug, but it is useful to serialize it with respect to device_offline() and device_online() for the same device (in case user space attempts to run them concurrently) which can be done with the help of device_lock().] Reported-by: Yasuaki Ishimatsu Reported-and-tested-by: Gu Zheng Suggested-by: Tejun Heo Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman Acked-by: Toshi Kani

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

2013-08-29T02:26:38Z

"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: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Cc: Yinghai Lu Reviewed-by: Yasuaki Ishimatsu Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

drivers/base/memory.c: introduce help macro to_memory_block

2013-08-28T22:47:38Z

Introduce help macro to_memory_block to hide the conversion(device-->memory_block), just clean up. Reviewed-by: Yasuaki Ishimatsu Signed-off-by: Gu Zheng Signed-off-by: Greg Kroah-Hartman

drivers: base: use standard device online/offline for state change

2013-08-21T18:52:20Z

There are two ways to set the online/offline state for a memory block: echo 0|1 > online and echo online|online_kernel|online_movable|offline > state. The state attribute can online a memory block with extra data, the "online type", where the online attribute uses a default online type of ONLINE_KEEP, same as echo online > state. Currently there is a state_mutex that provides consistency between the memory block state and the underlying memory. The problem is that this code does a lot of things that the common device layer can do for us, such as the serialization of the online/offline handlers using the device lock, setting the dev->offline field, and calling kobject_uevent(). This patch refactors the online/offline code to allow the common device_[online|offline] functions to be used. The result is a simpler and more common code path for the two state setting mechanisms. It also removes the state_mutex from the struct memory_block as the memory block device lock provides the state consistency. No functional change is intended by this patch. Signed-off-by: Seth Jennings Signed-off-by: Greg Kroah-Hartman

drivers: base: refactor add_memory_section() to add_memory_block()

2013-08-21T18:49:47Z

Right now memory_dev_init() maintains the memory block pointer between iterations of add_memory_section(). This is nasty. This patch refactors add_memory_section() to become add_memory_block(). The refactoring pulls the section scanning out of memory_dev_init() and simplifies the signature. Signed-off-by: Seth Jennings Signed-off-by: Greg Kroah-Hartman

drivers: base: remove improper get/put in add_memory_section()

2013-08-21T18:49:47Z

The path through add_memory_section() when the memory block already exists uses flawed refcounting logic. A get_device() is done on a memory block using a pointer that might not be valid as we dropped our previous reference and didn't obtain a new reference in the proper way. Lets stop pretending and just remove the get/put. The mem_sysfs_mutex, which we hold over the entire init loop now, will prevent the memory blocks from disappearing from under us. Signed-off-by: Seth Jennings Signed-off-by: Greg Kroah-Hartman

drivers: base: reduce add_memory_section() for boot-time only

2013-08-21T18:48:41Z

Now that add_memory_section() is only called from boot time, reduce the logic and remove the enum. Signed-off-by: Seth Jennings Signed-off-by: Greg Kroah-Hartman