- 13 2月, 2014 4 次提交
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由 Linus Walleij 提交于
As we want to actually define the parent frequency in the device tree for the ICST clocks, modify the clock registration function to take a parent argument. Cc: Mike Turquette <mturquette@linaro.org> Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
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由 Linus Walleij 提交于
This atomic commit changes the Integrator clock implementation and the machines to register clocks from the device tree and use these instead of the previous hard-coded clocks. In the clock implementation all hard-coded clocks and the special initialization function call goes away, and is replaced by two compatible strings for the two clocks available on the core module. Cc: Mike Turquette <mturquette@linaro.org> Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
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由 Linus Walleij 提交于
This modifies the SP804 driver so that the clock will be taken from the device tree node for the timer. Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Rob Herring <rob.herring@linaro.org> Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
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由 Linus Walleij 提交于
This adds the clock definitions to the Integrator/CP and Integrator/AP device trees. Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
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- 10 2月, 2014 8 次提交
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由 Linus Torvalds 提交于
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git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security由 Linus Torvalds 提交于
Pull SELinux fixes from James Morris. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: SELinux: Fix kernel BUG on empty security contexts. selinux: add SOCK_DIAG_BY_FAMILY to the list of netlink message types
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs由 Linus Torvalds 提交于
Pull vfs fixes from Al Viro: "A couple of fixes, both -stable fodder. The O_SYNC bug is fairly old..." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fix a kmap leak in virtio_console fix O_SYNC|O_APPEND syncing the wrong range on write()
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由 Al Viro 提交于
While we are at it, don't do kmap() under kmap_atomic(), *especially* for a page we'd allocated with GFP_KERNEL. It's spelled "page_address", and had that been more than that, we'd have a real trouble - kmap_high() can block, and doing that while holding kmap_atomic() is a Bad Idea(tm). Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
It actually goes back to 2004 ([PATCH] Concurrent O_SYNC write support) when sync_page_range() had been introduced; generic_file_write{,v}() correctly synced pos_after_write - written .. pos_after_write - 1 but generic_file_aio_write() synced pos_before_write .. pos_before_write + written - 1 instead. Which is not the same thing with O_APPEND, obviously. A couple of years later correct variant had been killed off when everything switched to use of generic_file_aio_write(). All users of generic_file_aio_write() are affected, and the same bug has been copied into other instances of ->aio_write(). The fix is trivial; the only subtle point is that generic_write_sync() ought to be inlined to avoid calculations useless for the majority of calls. Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs由 Linus Torvalds 提交于
Pull btrfs fixes from Chris Mason: "This is a small collection of fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Btrfs: fix data corruption when reading/updating compressed extents Btrfs: don't loop forever if we can't run because of the tree mod log btrfs: reserve no transaction units in btrfs_ioctl_set_features btrfs: commit transaction after setting label and features Btrfs: fix assert screwup for the pending move stuff
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip由 Linus Torvalds 提交于
Pull perf fixes from Ingo Molnar: "Tooling fixes, mostly related to the KASLR fallout, but also other fixes" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf buildid-cache: Check relocation when checking for existing kcore perf tools: Adjust kallsyms for relocated kernel perf tests: No need to set up ref_reloc_sym perf symbols: Prevent the use of kcore if the kernel has moved perf record: Get ref_reloc_sym from kernel map perf machine: Set up ref_reloc_sym in machine__create_kernel_maps() perf machine: Add machine__get_kallsyms_filename() perf tools: Add kallsyms__get_function_start() perf symbols: Fix symbol annotation for relocated kernel perf tools: Fix include for non x86 architectures perf tools: Fix AAAAARGH64 memory barriers perf tools: Demangle kernel and kernel module symbols too perf/doc: Remove mention of non-existent set_perf_event_pending() from design.txt
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- 09 2月, 2014 10 次提交
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When using a mix of compressed file extents and prealloc extents, it is possible to fill a page of a file with random, garbage data from some unrelated previous use of the page, instead of a sequence of zeroes. A simple sequence of steps to get into such case, taken from the test case I made for xfstests, is: _scratch_mkfs _scratch_mount "-o compress-force=lzo" $XFS_IO_PROG -f -c "pwrite -S 0x06 -b 18670 266978 18670" $SCRATCH_MNT/foobar $XFS_IO_PROG -c "falloc 26450 665194" $SCRATCH_MNT/foobar $XFS_IO_PROG -c "truncate 542872" $SCRATCH_MNT/foobar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foobar This results in the following file items in the fs tree: item 4 key (257 INODE_ITEM 0) itemoff 15879 itemsize 160 inode generation 6 transid 6 size 542872 block group 0 mode 100600 item 5 key (257 INODE_REF 256) itemoff 15863 itemsize 16 inode ref index 2 namelen 6 name: foobar item 6 key (257 EXTENT_DATA 0) itemoff 15810 itemsize 53 extent data disk byte 0 nr 0 gen 6 extent data offset 0 nr 24576 ram 266240 extent compression 0 item 7 key (257 EXTENT_DATA 24576) itemoff 15757 itemsize 53 prealloc data disk byte 12849152 nr 241664 gen 6 prealloc data offset 0 nr 241664 item 8 key (257 EXTENT_DATA 266240) itemoff 15704 itemsize 53 extent data disk byte 12845056 nr 4096 gen 6 extent data offset 0 nr 20480 ram 20480 extent compression 2 item 9 key (257 EXTENT_DATA 286720) itemoff 15651 itemsize 53 prealloc data disk byte 13090816 nr 405504 gen 6 prealloc data offset 0 nr 258048 The on disk extent at offset 266240 (which corresponds to 1 single disk block), contains 5 compressed chunks of file data. Each of the first 4 compress 4096 bytes of file data, while the last one only compresses 3024 bytes of file data. Therefore a read into the file region [285648 ; 286720[ (length = 4096 - 3024 = 1072 bytes) should always return zeroes (our next extent is a prealloc one). The solution here is the compression code path to zero the remaining (untouched) bytes of the last page it uncompressed data into, as the information about how much space the file data consumes in the last page is not known in the upper layer fs/btrfs/extent_io.c:__do_readpage(). In __do_readpage we were correctly zeroing the remainder of the page but only if it corresponds to the last page of the inode and if the inode's size is not a multiple of the page size. This would cause not only returning random data on reads, but also permanently storing random data when updating parts of the region that should be zeroed. For the example above, it means updating a single byte in the region [285648 ; 286720[ would store that byte correctly but also store random data on disk. A test case for xfstests follows soon. Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: NChris Mason <clm@fb.com>
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由 Josef Bacik 提交于
A user reported a 100% cpu hang with my new delayed ref code. Turns out I forgot to increase the count check when we can't run a delayed ref because of the tree mod log. If we can't run any delayed refs during this there is no point in continuing to look, and we need to break out. Thanks, Signed-off-by: NJosef Bacik <jbacik@fb.com> Signed-off-by: NChris Mason <clm@fb.com>
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由 David Sterba 提交于
Added in patch "btrfs: add ioctls to query/change feature bits online" modifications to superblock don't need to reserve metadata blocks when starting a transaction. Signed-off-by: NDavid Sterba <dsterba@suse.cz> Signed-off-by: NChris Mason <clm@fb.com>
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由 Jeff Mahoney 提交于
The set_fslabel ioctl uses btrfs_end_transaction, which means it's possible that the change will be lost if the system crashes, same for the newly set features. Let's use btrfs_commit_transaction instead. Signed-off-by: NJeff Mahoney <jeffm@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.cz> Signed-off-by: NChris Mason <clm@fb.com>
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由 Josef Bacik 提交于
Wang noticed that he was failing btrfs/030 even though me and Filipe couldn't reproduce. Turns out this is because Wang didn't have CONFIG_BTRFS_ASSERT set, which meant that a key part of Filipe's original patch was not being built in. This appears to be a mess up with merging Filipe's patch as it does not exist in his original patch. Fix this by changing how we make sure del_waiting_dir_move asserts that it did not error and take the function out of the ifdef check. This makes btrfs/030 pass with the assert on or off. Thanks, Signed-off-by: NJosef Bacik <jbacik@fb.com> Reviewed-by: NFilipe Manana <fdmanana@gmail.com> Signed-off-by: NChris Mason <clm@fb.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl由 Linus Torvalds 提交于
Pull pinctrl fixes from Linus Walleij: "First round of pin control fixes for v3.14: - Protect pinctrl_list_add() with the proper mutex. This was identified by RedHat. Caused nasty locking warnings was rootcased by Stanislaw Gruszka. - Avoid adding dangerous debugfs files when either half of the subsystem is unused: pinmux or pinconf. - Various fixes to various drivers: locking, hardware particulars, DT parsing, error codes" * tag 'pinctrl-v3.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: pinctrl: tegra: return correct error type pinctrl: do not init debugfs entries for unimplemented functionalities pinctrl: protect pinctrl_list add pinctrl: sirf: correct the pin index of ac97_pins group pinctrl: imx27: fix offset calculation in imx_read_2bit pinctrl: vt8500: Change devicetree data parsing pinctrl: imx27: fix wrong offset to ICONFB pinctrl: at91: use locked variant of irq_set_handler
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip由 Linus Torvalds 提交于
Pull irq fix from Thomas Gleixner: "Add a missing Kconfig dependency" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq: Generic irq chip requires IRQ_DOMAIN
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip由 Linus Torvalds 提交于
Pull x86 fixes from Peter Anvin: "Quite a varied little collection of fixes. Most of them are relatively small or isolated; the biggest one is Mel Gorman's fixes for TLB range flushing. A couple of AMD-related fixes (including not crashing when given an invalid microcode image) and fix a crash when compiled with gcov" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, microcode, AMD: Unify valid container checks x86, hweight: Fix BUG when booting with CONFIG_GCOV_PROFILE_ALL=y x86/efi: Allow mapping BGRT on x86-32 x86: Fix the initialization of physnode_map x86, cpu hotplug: Fix stack frame warning in check_irq_vectors_for_cpu_disable() x86/intel/mid: Fix X86_INTEL_MID dependencies arch/x86/mm/srat: Skip NUMA_NO_NODE while parsing SLIT mm, x86: Revisit tlb_flushall_shift tuning for page flushes except on IvyBridge x86: mm: change tlb_flushall_shift for IvyBridge x86/mm: Eliminate redundant page table walk during TLB range flushing x86/mm: Clean up inconsistencies when flushing TLB ranges mm, x86: Account for TLB flushes only when debugging x86/AMD/NB: Fix amd_set_subcaches() parameter type x86/quirks: Add workaround for AMD F16h Erratum792 x86, doc, kconfig: Fix dud URL for Microcode data
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git://github.com/kleikamp/linux-shaggy由 Linus Torvalds 提交于
Pull jfs fix from David Kleikamp: "Fix regression" * tag 'jfs-3.14-rc2' of git://github.com/kleikamp/linux-shaggy: jfs: fix generic posix ACL regression
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由 Dave Kleikamp 提交于
I missed a couple errors in reviewing the patches converting jfs to use the generic posix ACL function. Setting ACL's currently fails with -EOPNOTSUPP. Signed-off-by: NDave Kleikamp <dave.kleikamp@oracle.com> Reported-by: NMichael L. Semon <mlsemon35@gmail.com> Reviewed-by: NChristoph Hellwig <hch@lst.de>
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- 08 2月, 2014 15 次提交
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由 Richard Weinberger 提交于
On archs like S390 or um this driver cannot build nor work. Make it depend on HAS_IOMEM to bypass build failures. drivers/built-in.o: In function `dw_wdt_drv_probe': drivers/watchdog/dw_wdt.c:302: undefined reference to `devm_ioremap_resource' Signed-off-by: NRichard Weinberger <richard@nod.at> Signed-off-by: NWim Van Sebroeck <wim@iguana.be>
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由 Linus Torvalds 提交于
Merge tag 'driver-core-3.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core fix from Greg KH: "Here is a single kernfs fix to resolve a much-reported lockdep issue with the removal of entries in sysfs" * tag 'driver-core-3.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: kernfs: make kernfs_deactivate() honor KERNFS_LOCKDEP flag
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git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client由 Linus Torvalds 提交于
Pull ceph fixes from Sage Weil: "There is an RBD fix for a crash due to the immutable bio changes, an error path fix, and a locking fix in the recent redirect support" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: libceph: do not dereference a NULL bio pointer libceph: take map_sem for read in handle_reply() libceph: factor out logic from ceph_osdc_start_request() libceph: fix error handling in ceph_osdc_init()
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git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux由 Linus Torvalds 提交于
Pull arm64 fixes from Catalin Marinas: - Relax VDSO alignment requirements so that the kernel-picked one (4K) does not conflict with the dynamic linker's one (64K) - VDSO gettimeofday fix - Barrier fixes for atomic operations and cache flushing - TLB invalidation when overriding early page mappings during boot - Wired up new 32-bit arm (compat) syscalls - LSM_MMAP_MIN_ADDR when COMPAT is enabled - defconfig update - Clean-up (comments, pgd_alloc). * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: defconfig: Expand default enabled features arm64: asm: remove redundant "cc" clobbers arm64: atomics: fix use of acquire + release for full barrier semantics arm64: barriers: allow dsb macro to take option parameter security: select correct default LSM_MMAP_MIN_ADDR on arm on arm64 arm64: compat: Wire up new AArch32 syscalls arm64: vdso: update wtm fields for CLOCK_MONOTONIC_COARSE arm64: vdso: fix coarse clock handling arm64: simplify pgd_alloc arm64: fix typo: s/SERRROR/SERROR/ arm64: Invalidate the TLB when replacing pmd entries during boot arm64: Align CMA sizes to PAGE_SIZE arm64: add DSB after icache flush in __flush_icache_all() arm64: vdso: prevent ld from aligning PT_LOAD segments to 64k
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git://git.linux-mips.org/pub/scm/ralf/upstream-linus由 Linus Torvalds 提交于
Pull MIPS updates from Ralf Baechle: "hree minor patches. All have sat in -next for a few days" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: MIPS: fpu.h: Fix build when CONFIG_BUG is not set MIPS: Wire up sched_setattr/sched_getattr syscalls MIPS: Alchemy: Fix DB1100 GPIO registration
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git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media由 Linus Torvalds 提交于
Pull media fixes from Mauro Carvalho Chehab: "A series of small fixes. Mostly driver ones. There is one core regression fix on a patch that was meant to fix some race issues on vb2, but that actually caused more harm than good. So, we're just reverting it for now" * 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: [media] adv7842: Composite free-run platfrom-data fix [media] v4l2-dv-timings: fix GTF calculation [media] hdpvr: Fix memory leak in debug [media] af9035: add ID [2040:f900] Hauppauge WinTV-MiniStick 2 [media] mxl111sf: Fix compile when CONFIG_DVB_USB_MXL111SF is unset [media] mxl111sf: Fix unintentional garbage stack read [media] cx24117: use a valid dev pointer for dev_err printout [media] cx24117: remove dead code in always 'false' if statement [media] update Michael Krufky's email address [media] vb2: Check if there are buffers before streamon [media] Revert "[media] videobuf_vm_{open,close} race fixes" [media] go7007-loader: fix usb_dev leak [media] media: bt8xx: add missing put_device call [media] exynos4-is: Compile in fimc-lite runtime PM callbacks conditionally [media] exynos4-is: Compile in fimc runtime PM callbacks conditionally [media] exynos4-is: Fix error paths in probe() for !pm_runtime_enabled() [media] s5p-jpeg: Fix wrong NV12 format parameters [media] s5k5baf: allow to handle arbitrary long i2c sequences
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git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging由 Linus Torvalds 提交于
Pull hwmon fixes from Guenter Roeck: "Fix PMBus driver problem with some multi-page voltage sensors and fix da9055 interrupt initialization" * tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging: hwmon: (da9055) Remove use of regmap_irq_get_virq() hwmon: (pmbus) Support per-page exponent in linear mode
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git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm由 Linus Torvalds 提交于
Pull ACPI and power management fixes from Rafael Wysocki: "These include a fix for a recent ACPI hotplug regression, four concurrency related fixes and one PCI device removal fix for ACPI-based PCI hotplug (ACPIPHP), intel_pstate fix that should go into stable, three simple ACPI cleanups and a new entry for the ACPI video blacklist. Specifics: - Fix for a recent ACPI hotplug regression causing a NULL pointer dereference to occur while handling ACPI eject notifications for already ejected devices. From Toshi Kani. - Four concurrency-related fixes for ACPIPHP. Two of them add missing locking and the other two fix race conditions related to reference counting. - ACPIPHP fix to avoid NULL pointer dereferences during device removal involving Virtual Funcions. - intel_pstate fix to make it compute the percentage of time the CPU is busy properly. From Dirk Brandewie. - Removal of two unnecessary NULL pointer checks in ACPI code and a fix for sscanf() format string from Dan Carpenter and Luis G.F. - New ACPI video blacklist entry for HP EliteBook Revolve 810 from Mika Westerberg" * tag 'pm+acpi-3.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: ACPI / hotplug: Fix panic on eject to ejected device ACPI / battery: Fix incorrect sscanf() string in acpi_battery_init_alarm() ACPI / proc: remove unneeded NULL check ACPI / utils: remove a pointless NULL check ACPI / video: Add HP EliteBook Revolve 810 to the blacklist intel_pstate: Take core C0 time into account for core busy calculation ACPI / hotplug / PCI: Fix bridge removal race vs dock events ACPI / hotplug / PCI: Fix bridge removal race in handle_hotplug_event() ACPI / hotplug / PCI: Scan root bus under the PCI rescan-remove lock ACPI / hotplug / PCI: Move PCI rescan-remove locking to hotplug_event() ACPI / hotplug / PCI: Remove entries from bus->devices in reverse order
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由 Ilya Dryomov 提交于
Commit f38a5181 ("ceph: Convert to immutable biovecs") introduced a NULL pointer dereference, which broke rbd in -rc1. Fix it. Cc: Kent Overstreet <kmo@daterainc.com> Signed-off-by: NIlya Dryomov <ilya.dryomov@inktank.com> Reviewed-by: NSage Weil <sage@inktank.com>
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由 H. Peter Anvin 提交于
* Avoid WARN_ON() when mapping BGRT on Baytrail (EFI 32-bit). Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
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由 Ilya Dryomov 提交于
Handling redirect replies requires both map_sem and request_mutex. Taking map_sem unconditionally near the top of handle_reply() avoids possible race conditions that arise from releasing request_mutex to be able to acquire map_sem in redirect reply case. (Lock ordering is: map_sem, request_mutex, crush_mutex.) Signed-off-by: NIlya Dryomov <ilya.dryomov@inktank.com> Reviewed-by: NSage Weil <sage@inktank.com>
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由 Ilya Dryomov 提交于
Factor out logic from ceph_osdc_start_request() into a new helper, __ceph_osdc_start_request(). ceph_osdc_start_request() now amounts to taking locks and calling __ceph_osdc_start_request(). Signed-off-by: NIlya Dryomov <ilya.dryomov@inktank.com> Reviewed-by: NSage Weil <sage@inktank.com>
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由 Mark Rutland 提交于
FPGA implementations of the Cortex-A57 and Cortex-A53 are now available in the form of the SMM-A57 and SMM-A53 Soft Macrocell Models (SMMs) for Versatile Express. As these attach to a Motherboard Express V2M-P1 it would be useful to have support for some V2M-P1 peripherals enabled by default. Additionally a couple of of features have been introduced since the last defconfig update (CMA, jump labels) that would be good to have enabled by default to ensure they are build and boot tested. This patch updates the arm64 defconfig to enable support for these devices and features. The arm64 Kconfig is modified to select HAVE_PATA_PLATFORM, which is required to enable support for the CompactFlash controller on the V2M-P1. A few options which don't need to appear in defconfig are trimmed: * BLK_DEV - selected by default * EXPERIMENTAL - otherwise gone from the kernel * MII - selected by drivers which require it * USB_SUPPORT - selected by default Signed-off-by: NMark Rutland <mark.rutland@arm.com> Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
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由 Will Deacon 提交于
cbnz/tbnz don't update the condition flags, so remove the "cc" clobbers from inline asm blocks that only use these instructions to implement conditional branches. Signed-off-by: NWill Deacon <will.deacon@arm.com> Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
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由 Will Deacon 提交于
Linux requires a number of atomic operations to provide full barrier semantics, that is no memory accesses after the operation can be observed before any accesses up to and including the operation in program order. On arm64, these operations have been incorrectly implemented as follows: // A, B, C are independent memory locations <Access [A]> // atomic_op (B) 1: ldaxr x0, [B] // Exclusive load with acquire <op(B)> stlxr w1, x0, [B] // Exclusive store with release cbnz w1, 1b <Access [C]> The assumption here being that two half barriers are equivalent to a full barrier, so the only permitted ordering would be A -> B -> C (where B is the atomic operation involving both a load and a store). Unfortunately, this is not the case by the letter of the architecture and, in fact, the accesses to A and C are permitted to pass their nearest half barrier resulting in orderings such as Bl -> A -> C -> Bs or Bl -> C -> A -> Bs (where Bl is the load-acquire on B and Bs is the store-release on B). This is a clear violation of the full barrier requirement. The simple way to fix this is to implement the same algorithm as ARMv7 using explicit barriers: <Access [A]> // atomic_op (B) dmb ish // Full barrier 1: ldxr x0, [B] // Exclusive load <op(B)> stxr w1, x0, [B] // Exclusive store cbnz w1, 1b dmb ish // Full barrier <Access [C]> but this has the undesirable effect of introducing *two* full barrier instructions. A better approach is actually the following, non-intuitive sequence: <Access [A]> // atomic_op (B) 1: ldxr x0, [B] // Exclusive load <op(B)> stlxr w1, x0, [B] // Exclusive store with release cbnz w1, 1b dmb ish // Full barrier <Access [C]> The simple observations here are: - The dmb ensures that no subsequent accesses (e.g. the access to C) can enter or pass the atomic sequence. - The dmb also ensures that no prior accesses (e.g. the access to A) can pass the atomic sequence. - Therefore, no prior access can pass a subsequent access, or vice-versa (i.e. A is strictly ordered before C). - The stlxr ensures that no prior access can pass the store component of the atomic operation. The only tricky part remaining is the ordering between the ldxr and the access to A, since the absence of the first dmb means that we're now permitting re-ordering between the ldxr and any prior accesses. From an (arbitrary) observer's point of view, there are two scenarios: 1. We have observed the ldxr. This means that if we perform a store to [B], the ldxr will still return older data. If we can observe the ldxr, then we can potentially observe the permitted re-ordering with the access to A, which is clearly an issue when compared to the dmb variant of the code. Thankfully, the exclusive monitor will save us here since it will be cleared as a result of the store and the ldxr will retry. Notice that any use of a later memory observation to imply observation of the ldxr will also imply observation of the access to A, since the stlxr/dmb ensure strict ordering. 2. We have not observed the ldxr. This means we can perform a store and influence the later ldxr. However, that doesn't actually tell us anything about the access to [A], so we've not lost anything here either when compared to the dmb variant. This patch implements this solution for our barriered atomic operations, ensuring that we satisfy the full barrier requirements where they are needed. Cc: <stable@vger.kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: NWill Deacon <will.deacon@arm.com> Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
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- 07 2月, 2014 3 次提交
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由 Adam Thomson 提交于
Remove use of regmap_irq_get_virq() in driver probe which was conflicting with use of platform_get_irq_byname(). platform_get_irq_byname() already returns the VIRQ number due to MFD core translation so using regmap_irq_get_virq() on that returned value results in an incorrect IRQ being requested. The driver probes then fail because of this. Signed-off-by: NAdam Thomson <Adam.Thomson.Opensource@diasemi.com> Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
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由 Rafael J. Wysocki 提交于
* acpi-cleanup: ACPI / battery: Fix incorrect sscanf() string in acpi_battery_init_alarm() ACPI / proc: remove unneeded NULL check ACPI / utils: remove a pointless NULL check * acpi-video: ACPI / video: Add HP EliteBook Revolve 810 to the blacklist
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由 Rafael J. Wysocki 提交于
* pm-cpufreq: intel_pstate: Take core C0 time into account for core busy calculation
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