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2016-05-20bpf: rather use get_random_int for randomizationsDaniel Borkmann1-2/+2
Start address randomization and blinding in BPF currently use prandom_u32(). prandom_u32() values are not exposed to unpriviledged user space to my knowledge, but given other kernel facilities such as ASLR, stack canaries, etc make use of stronger get_random_int(), we better make use of it here as well given blinding requests successively new random values. get_random_int() has minimal entropy pool depletion, is not cryptographically secure, but doesn't need to be for our use cases here. Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-19Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds1-10/+3
Pull MIPS updates from Ralf Baechle: "This is the main pull request for MIPS for 4.7. Here's the summary of the changes: - ATH79: Support for DTB passuing using the UHI boot protocol - ATH79: Remove support for builtin DTB. - ATH79: Add zboot debug serial support. - ATH79: Add initial support for Dragino MS14 (Dragine 2), Onion Omega and DPT-Module. - ATH79: Update devicetree clock support for AR9132 and AR9331. - ATH79: Cleanup the DT code. - ATH79: Support newer SOCs in ath79_ddr_ctrl_init. - ATH79: Fix regression in PCI window initialization. - BCM47xx: Move SPROM driver to drivers/firmware/ - BCM63xx: Enable partition parser in defconfig. - BMIPS: BMIPS5000 has I cache filing from D cache - BMIPS: BMIPS: Add cpu-feature-overrides.h - BMIPS: Add Whirlwind support - BMIPS: Adjust mips-hpt-frequency for BCM7435 - BMIPS: Remove maxcpus from BCM97435SVMB DTS - BMIPS: Add missing 7038 L1 register cells to BCM7435 - BMIPS: Various tweaks to initialization code. - BMIPS: Enable partition parser in defconfig. - BMIPS: Cache tweaks. - BMIPS: Add UART, I2C and SATA devices to DT. - BMIPS: Add BCM6358 and BCM63268support - BMIPS: Add device tree example for BCM6358. - BMIPS: Improve Improve BCM6328 and BCM6368 device trees - Lantiq: Add support for device tree file from boot loader - Lantiq: Allow build with no built-in DT. - Loongson 3: Reserve 32MB for RS780E integrated GPU. - Loongson 3: Fix build error after ld-version.sh modification - Loongson 3: Move chipset ACPI code from drivers to arch. - Loongson 3: Speedup irq processing. - Loongson 3: Add basic Loongson 3A support. - Loongson 3: Set cache flush handlers to nop. - Loongson 3: Invalidate special TLBs when needed. - Loongson 3: Fast TLB refill handler. - MT7620: Fallback strategy for invalid syscfg0. - Netlogic: Fix CP0_EBASE redefinition warnings - Octeon: Initialization fixes - Octeon: Add DTS files for the D-Link DSR-1000N and EdgeRouter Lite - Octeon: Enable add Octeon-drivers in cavium_octeon_defconfig - Octeon: Correctly handle endian-swapped initramfs images. - Octeon: Support CN73xx, CN75xx and CN78xx. - Octeon: Remove dead code from cvmx-sysinfo. - Octeon: Extend number of supported CPUs past 32. - Octeon: Remove some code limiting NR_IRQS to 255. - Octeon: Simplify octeon_irq_ciu_gpio_set_type. - Octeon: Mark some functions __init in smp.c - Octeon: Octeon: Add Octeon III CN7xxx interface detection - PIC32: Add serial driver and bindings for it. - PIC32: Add PIC32 deadman timer driver and bindings. - PIC32: Add PIC32 clock timer driver and bindings. - Pistachio: Determine SoC revision during boot - Sibyte: Fix Kconfig dependencies of SIBYTE_BUS_WATCHER. - Sibyte: Strip redundant comments from bcm1480_regs.h. - Panic immediately if panic_on_oops is set. - module: fix incorrect IS_ERR_VALUE macro usage. - module: Make consistent use of pr_* - Remove no longer needed work_on_cpu() call. - Remove CONFIG_IPV6_PRIVACY from defconfigs. - Fix registers of non-crashing CPUs in dumps. - Handle MIPSisms in new vmcore_elf32_check_arch. - Select CONFIG_HANDLE_DOMAIN_IRQ and make it work. - Allow RIXI to be used on non-R2 or R6 cores. - Reserve nosave data for hibernation - Fix siginfo.h to use strict POSIX types. - Don't unwind user mode with EVA. - Fix watchpoint restoration - Ptrace watchpoints for R6. - Sync icache when it fills from dcache - I6400 I-cache fills from dcache. - Various MSA fixes. - Cleanup MIPS_CPU_* definitions. - Signal: Move generic copy_siginfo to signal.h - Signal: Fix uapi include in exported asm/siginfo.h - Timer fixes for sake of KVM. - XPA TLB refill fixes. - Treat perf counter feature - Update John Crispin's email address - Add PIC32 watchdog and bindings. - Handle R10000 LL/SC bug in set_pte() - cpufreq: Various fixes for Longson1. - R6: Fix R2 emulation. - mathemu: Cosmetic fix to ADDIUPC emulation, plenty of other small fixes - ELF: ABI and FP fixes. - Allow for relocatable kernel and use that to support KASLR. - Fix CPC_BASE_ADDR mask - Plenty fo smp-cps, CM, R6 and M6250 fixes. - Make reset_control_ops const. - Fix kernel command line handling of leading whitespace. - Cleanups to cache handling. - Add brcm, bcm6345-l1-intc device tree bindings. - Use generic clkdev.h header - Remove CLK_IS_ROOT usage. - Misc small cleanups. - CM: Fix compilation error when !MIPS_CM - oprofile: Fix a preemption issue - Detect DSP ASE v3 support:1" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (275 commits) MIPS: pic32mzda: fix getting timer clock rate. MIPS: ath79: fix regression in PCI window initialization MIPS: ath79: make ath79_ddr_ctrl_init() compatible for newer SoCs MIPS: Fix VZ probe gas errors with binutils <2.24 MIPS: perf: Fix I6400 event numbers MIPS: DEC: Export `ioasic_ssr_lock' to modules MIPS: MSA: Fix a link error on `_init_msa_upper' with older GCC MIPS: CM: Fix compilation error when !MIPS_CM MIPS: Fix genvdso error on rebuild USB: ohci-jz4740: Remove obsolete driver MIPS: JZ4740: Probe OHCI platform device via DT MIPS: JZ4740: Qi LB60: Remove support for AVT2 variant MIPS: pistachio: Determine SoC revision during boot MIPS: BMIPS: Adjust mips-hpt-frequency for BCM7435 mips: mt7620: fallback to SDRAM when syscfg0 does not have a valid value for the memory type MIPS: Prevent "restoration" of MSA context in non-MSA kernels MIPS: cevt-r4k: Dynamically calculate min_delta_ns MIPS: malta-time: Take seconds into account MIPS: malta-time: Start GIC count before syncing to RTC MIPS: Force CPUs to lose FP context during mode switches ...
2016-05-19Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-securityLinus Torvalds2-4/+5
Pull security subsystem updates from James Morris: "Highlights: - A new LSM, "LoadPin", from Kees Cook is added, which allows forcing of modules and firmware to be loaded from a specific device (this is from ChromeOS, where the device as a whole is verified cryptographically via dm-verity). This is disabled by default but can be configured to be enabled by default (don't do this if you don't know what you're doing). - Keys: allow authentication data to be stored in an asymmetric key. Lots of general fixes and updates. - SELinux: add restrictions for loading of kernel modules via finit_module(). Distinguish non-init user namespace capability checks. Apply execstack check on thread stacks" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (48 commits) LSM: LoadPin: provide enablement CONFIG Yama: use atomic allocations when reporting seccomp: Fix comment typo ima: add support for creating files using the mknodat syscall ima: fix ima_inode_post_setattr vfs: forbid write access when reading a file into memory fs: fix over-zealous use of "const" selinux: apply execstack check on thread stacks selinux: distinguish non-init user namespace capability checks LSM: LoadPin for kernel file loading restrictions fs: define a string representation of the kernel_read_file_id enumeration Yama: consolidate error reporting string_helpers: add kstrdup_quotable_file string_helpers: add kstrdup_quotable_cmdline string_helpers: add kstrdup_quotable selinux: check ss_initialized before revalidating an inode label selinux: delay inode label lookup as long as possible selinux: don't revalidate an inode's label when explicitly setting it selinux: Change bool variable name to index. KEYS: Add KEYCTL_DH_COMPUTE command ...
2016-05-18Merge tag 'trace-v4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-traceLinus Torvalds10-284/+3930
Pull tracing updates from Steven Rostedt: "This includes two new updates for the ftrace infrastructure. - With the changing of the code for filtering events by pid, from a list of pids to a bitmask, we can now easily implement following forks. With a new tracing option "event-fork" which, when set, will have tasks with pids in set_event_pid, when they fork, to have their child pids added to set_event_pid and the child will be traced as well. Note, if "event-fork" is set and a task with its pid in set_event_pid exits, its pid will be removed from set_event_pid - The addition of Tom Zanussi's hist triggers. This includes a very thorough documentatino on how to use the hist triggers with events. This introduces a quick and easy way to get histogram data from events and their fields. Some other cleanups and updates were added as well. Like Masami Hiramatsu added test cases for the event trigger and hist triggers. Also I added a speed up of filtering by using a temp buffer when filters are set" * tag 'trace-v4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (45 commits) tracing: Use temp buffer when filtering events tracing: Remove TRACE_EVENT_FL_USE_CALL_FILTER logic tracing: Remove unused function trace_current_buffer_lock_reserve() tracing: Remove one use of trace_current_buffer_lock_reserve() tracing: Have trace_buffer_unlock_commit() call the _regs version with NULL tracing: Remove unused function trace_current_buffer_discard_commit() tracing: Move trace_buffer_unlock_commit{_regs}() to local header tracing: Fold filter_check_discard() into its only user tracing: Make filter_check_discard() local tracing: Move event_trigger_unlock_commit{_regs}() to local header tracing: Don't use the address of the buffer array name in copy_from_user tracing: Handle tracing_map_alloc_elts() error path correctly tracing: Add check for NULL event field when creating hist field tracing: checking for NULL instead of IS_ERR() tracing: Do not inherit event-fork option for instances tracing: Fix unsigned comparison to zero in hist trigger code kselftests/ftrace: Add a test for log2 modifier of hist trigger tracing: Add hist trigger 'log2' modifier kselftests/ftrace: Add hist trigger testcases kselftests/ftrace : Add event trigger testcases ...
2016-05-18Merge branch 'stable-4.7' of git://git.infradead.org/users/pcmoore/auditLinus Torvalds3-29/+21
Pull audit updates from Paul Moore: "Four small audit patches for 4.7. Two are simple cleanups around the audit thread management code, one adds a tty field to AUDIT_LOGIN events, and the final patch makes tty_name() usable regardless of CONFIG_TTY. Nothing controversial, and it all passes our regression test" * 'stable-4.7' of git://git.infradead.org/users/pcmoore/audit: tty: provide tty_name() even without CONFIG_TTY audit: add tty field to LOGIN event audit: we don't need to __set_current_state(TASK_RUNNING) audit: cleanup prune_tree_thread
2016-05-18Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds1-29/+8
Pull misc vfs cleanups from Al Viro: "Assorted cleanups and fixes all over the place" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: coredump: only charge written data against RLIMIT_CORE coredump: get rid of coredump_params->written ecryptfs_lookup(): try either only encrypted or plaintext name ecryptfs: avoid multiple aliases for directories bpf: reject invalid names right in ->lookup() __d_alloc(): treat NULL name as QSTR("/", 1) mtd: switch ubi_open_volume_path() to vfs_stat() mtd: switch open_mtd_by_chdev() to use of vfs_stat()
2016-05-17Merge tag 'gpio-v4.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpioLinus Torvalds1-0/+1
Pull GPIO updates from Linus Walleij: "This is the bulk of GPIO changes for kernel cycle v4.7: Core infrastructural changes: - Support for natively single-ended GPIO driver stages. This means that if the hardware has registers to configure open drain or open source configuration, we use that rather than (as we did before) try to emulate it by switching the line to an input to get high impedance. This is also documented throughly in Documentation/gpio/driver.txt for those of you who did not understand one word of what I just wrote. - Start to do away with the unnecessarily complex and unitelligible ARCH_REQUIRE_GPIOLIB and ARCH_WANT_OPTIONAL_GPIOLIB, another evolutional artifact from the time when the GPIO subsystem was unmaintained. Archs can now just select GPIOLIB and be done with it, cleanups to arches will trickle in for the next kernel. Some minor archs ACKed the changes immediately so these are included in this pull request. - Advancing the use of the data pointer inside the GPIO device for storing driver data by switching the PowerPC, Super-H Unicore and a few other subarches or subsystem drivers in ALSA SoC, Input, serial, SSB, staging etc to use it. - The initialization now reads the input/output state of the GPIO lines, so that each GPIO descriptor knows - if this callback is implemented - whether the line is input or output. This also reflects nicely in userspace "lsgpio". - It is now possible to name GPIO producer names, line names, from the device tree. (Platform data has been supported for a while). I bet we will get a similar mechanism for ACPI one of those days. This makes is possible to get sensible producer names for e.g. GPIO rails in "lsgpio" in userspace. New drivers: - New driver for the Loongson1. - The XLP driver now supports Broadcom Vulcan ARM64. - The IT87 driver now supports IT8620 and IT8628. - The PCA953X driver now supports Galileo Gen2. Driver improvements: - MCP23S08 was switched to use the gpiolib irqchip helpers and now also suppors level-triggered interrupts. - 74x164 and RCAR now supports the .set_multiple() callback - AMDPT was converted to use generic GPIO. - TC3589x, TPS65218, SX150X, F7188X, MENZ127, VX855, WM831X, WM8994 support the new single ended callback for open drain and in some cases open source. - Implement the .get_direction() callback for a few more drivers like PL061, Xgene. Cleanups: - Paul Gortmaker combed through the drivers and de-modularized those who are not really modules. - Move the GPIO poweroff DT bindings to the power subdir where they belong. - Rename gpio-generic.c to gpio-mmio.c, which is much more to the point. That's what it is handling, nothing more, nothing less" * tag 'gpio-v4.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (126 commits) MIPS: do away with ARCH_[WANT_OPTIONAL|REQUIRE]_GPIOLIB gpio: zevio: make it explicitly non-modular gpio: timberdale: make it explicitly non-modular gpio: stmpe: make it explicitly non-modular gpio: sodaville: make it explicitly non-modular pinctrl: sh-pfc: Let gpio_chip.to_irq() return zero on error gpio: dwapb: Add ACPI device ID for DWAPB GPIO controller on X-Gene platforms gpio: dt-bindings: add wd,mbl-gpio bindings gpio: of: make it possible to name GPIO lines gpio: make gpiod_to_irq() return negative for NO_IRQ gpio: xgene: implement .get_direction() gpio: xgene: Enable ACPI support for X-Gene GFC GPIO driver gpio: tegra: Implement gpio_get_direction callback gpio: set up initial state from .get_direction() gpio: rename gpio-generic.c into gpio-mmio.c gpio: generic: fix GPIO_GENERIC_PLATFORM is set to module case gpio: dwapb: add gpio-signaled acpi event support gpio: dwapb: convert device node to fwnode gpio: dwapb: remove name from dwapb_port_property gpio/qoriq: select IRQ_DOMAIN ...
2016-05-17Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatchingLinus Torvalds3-64/+266
Pull livepatching updates from Jiri Kosina: - remove of our own implementation of architecture-specific relocation code and leveraging existing code in the module loader to perform arch-dependent work, from Jessica Yu. The relevant patches have been acked by Rusty (for module.c) and Heiko (for s390). - live patching support for ppc64le, which is a joint work of Michael Ellerman and Torsten Duwe. This is coming from topic branch that is share between livepatching.git and ppc tree. - addition of livepatching documentation from Petr Mladek * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching: livepatch: make object/func-walking helpers more robust livepatch: Add some basic livepatch documentation powerpc/livepatch: Add live patching support on ppc64le powerpc/livepatch: Add livepatch stack to struct thread_info powerpc/livepatch: Add livepatch header livepatch: Allow architectures to specify an alternate ftrace location ftrace: Make ftrace_location_range() global livepatch: robustify klp_register_patch() API error checking Documentation: livepatch: outline Elf format and requirements for patch modules livepatch: reuse module loader code to write relocations module: s390: keep mod_arch_specific for livepatch modules module: preserve Elf information for livepatch modules Elf: add livepatch-specific Elf constants
2016-05-17Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds13-231/+1122
Pull networking updates from David Miller: "Highlights: 1) Support SPI based w5100 devices, from Akinobu Mita. 2) Partial Segmentation Offload, from Alexander Duyck. 3) Add GMAC4 support to stmmac driver, from Alexandre TORGUE. 4) Allow cls_flower stats offload, from Amir Vadai. 5) Implement bpf blinding, from Daniel Borkmann. 6) Optimize _ASYNC_ bit twiddling on sockets, unless the socket is actually using FASYNC these atomics are superfluous. From Eric Dumazet. 7) Run TCP more preemptibly, also from Eric Dumazet. 8) Support LED blinking, EEPROM dumps, and rxvlan offloading in mlx5e driver, from Gal Pressman. 9) Allow creating ppp devices via rtnetlink, from Guillaume Nault. 10) Improve BPF usage documentation, from Jesper Dangaard Brouer. 11) Support tunneling offloads in qed, from Manish Chopra. 12) aRFS offloading in mlx5e, from Maor Gottlieb. 13) Add RFS and RPS support to SCTP protocol, from Marcelo Ricardo Leitner. 14) Add MSG_EOR support to TCP, this allows controlling packet coalescing on application record boundaries for more accurate socket timestamp sampling. From Martin KaFai Lau. 15) Fix alignment of 64-bit netlink attributes across the board, from Nicolas Dichtel. 16) Per-vlan stats in bridging, from Nikolay Aleksandrov. 17) Several conversions of drivers to ethtool ksettings, from Philippe Reynes. 18) Checksum neutral ILA in ipv6, from Tom Herbert. 19) Factorize all of the various marvell dsa drivers into one, from Vivien Didelot 20) Add VF support to qed driver, from Yuval Mintz" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1649 commits) Revert "phy dp83867: Fix compilation with CONFIG_OF_MDIO=m" Revert "phy dp83867: Make rgmii parameters optional" r8169: default to 64-bit DMA on recent PCIe chips phy dp83867: Make rgmii parameters optional phy dp83867: Fix compilation with CONFIG_OF_MDIO=m bpf: arm64: remove callee-save registers use for tmp registers asix: Fix offset calculation in asix_rx_fixup() causing slow transmissions switchdev: pass pointer to fib_info instead of copy net_sched: close another race condition in tcf_mirred_release() tipc: fix nametable publication field in nl compat drivers: net: Don't print unpopulated net_device name qed: add support for dcbx. ravb: Add missing free_irq() calls to ravb_close() qed: Remove a stray tab net: ethernet: fec-mpc52xx: use phy_ethtool_{get|set}_link_ksettings net: ethernet: fec-mpc52xx: use phydev from struct net_device bpf, doc: fix typo on bpf_asm descriptions stmmac: hardware TX COE doesn't work when force_thresh_dma_mode is set net: ethernet: fs-enet: use phy_ethtool_{get|set}_link_ksettings net: ethernet: fs-enet: use phydev from struct net_device ...
2016-05-17Merge branch 'for-4.7/core' of git://git.kernel.dk/linux-blockLinus Torvalds1-0/+2
Pull core block layer updates from Jens Axboe: "This is the core block IO changes for this merge window. Nothing earth shattering in here, it's mostly just fixes. In detail: - Fix for a long standing issue where wrong ordering in blk-mq caused order_to_size() to spew a warning. From Bart. - Async discard support from Christoph. Basically just splitting our sync interface into a submit + wait part. - Add a cleaner interface for flagging whether a device has a write back cache or not. We've previously overloaded blk_queue_flush() with this, but let's make it more explicit. Drivers cleaned up and updated in the drivers pull request. From me. - Fix for a double check for whether IO accounting is enabled or not. From Michael Callahan. - Fix for the async discard from Mike Snitzer, reinstating the early EOPNOTSUPP return if the device doesn't support discards. - Also from Mike, export bio_inc_remaining() so dm can drop it's private copy of it. - From Ming Lin, add support for passing in an offset for request payloads. - Tag function export from Sagi, which will be used in NVMe in the drivers pull. - Two blktrace related fixes from Shaohua. - Propagate NOMERGE flag when making a request from a bio, also from Shaohua. - An optimization to not parse cgroup paths in blk-throttle, if we don't need to. From Shaohua" * 'for-4.7/core' of git://git.kernel.dk/linux-block: blk-mq: fix undefined behaviour in order_to_size() blk-throttle: don't parse cgroup path if trace isn't enabled blktrace: add missed mask name blktrace: delete garbage for message trace block: make bio_inc_remaining() interface accessible again block: reinstate early return of -EOPNOTSUPP from blkdev_issue_discard block: Minor blk_account_io_start usage cleanup block: add __blkdev_issue_discard block: remove struct bio_batch block: copy NOMERGE flag from bio to request block: add ability to flag write back caching on a device blk-mq: Export tagset iter function block: add offset in blk_add_request_payload() writeback: Fix performance regression in wb_over_bg_thresh()
2016-05-17Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds1-1/+1
Pull parallel filesystem directory handling update from Al Viro. This is the main parallel directory work by Al that makes the vfs layer able to do lookup and readdir in parallel within a single directory. That's a big change, since this used to be all protected by the directory inode mutex. The inode mutex is replaced by an rwsem, and serialization of lookups of a single name is done by a "in-progress" dentry marker. The series begins with xattr cleanups, and then ends with switching filesystems over to actually doing the readdir in parallel (switching to the "iterate_shared()" that only takes the read lock). A more detailed explanation of the process from Al Viro: "The xattr work starts with some acl fixes, then switches ->getxattr to passing inode and dentry separately. This is the point where the things start to get tricky - that got merged into the very beginning of the -rc3-based #work.lookups, to allow untangling the security_d_instantiate() mess. The xattr work itself proceeds to switch a lot of filesystems to generic_...xattr(); no complications there. After that initial xattr work, the series then does the following: - untangle security_d_instantiate() - convert a bunch of open-coded lookup_one_len_unlocked() to calls of that thing; one such place (in overlayfs) actually yields a trivial conflict with overlayfs fixes later in the cycle - overlayfs ended up switching to a variant of lookup_one_len_unlocked() sans the permission checks. I would've dropped that commit (it gets overridden on merge from #ovl-fixes in #for-next; proper resolution is to use the variant in mainline fs/overlayfs/super.c), but I didn't want to rebase the damn thing - it was fairly late in the cycle... - some filesystems had managed to depend on lookup/lookup exclusion for *fs-internal* data structures in a way that would break if we relaxed the VFS exclusion. Fixing hadn't been hard, fortunately. - core of that series - parallel lookup machinery, replacing ->i_mutex with rwsem, making lookup_slow() take it only shared. At that point lookups happen in parallel; lookups on the same name wait for the in-progress one to be done with that dentry. Surprisingly little code, at that - almost all of it is in fs/dcache.c, with fs/namei.c changes limited to lookup_slow() - making it use the new primitive and actually switching to locking shared. - parallel readdir stuff - first of all, we provide the exclusion on per-struct file basis, same as we do for read() vs lseek() for regular files. That takes care of most of the needed exclusion in readdir/readdir; however, these guys are trickier than lookups, so I went for switching them one-by-one. To do that, a new method '->iterate_shared()' is added and filesystems are switched to it as they are either confirmed to be OK with shared lock on directory or fixed to be OK with that. I hope to kill the original method come next cycle (almost all in-tree filesystems are switched already), but it's still not quite finished. - several filesystems get switched to parallel readdir. The interesting part here is dealing with dcache preseeding by readdir; that needs minor adjustment to be safe with directory locked only shared. Most of the filesystems doing that got switched to in those commits. Important exception: NFS. Turns out that NFS folks, with their, er, insistence on VFS getting the fuck out of the way of the Smart Filesystem Code That Knows How And What To Lock(tm) have grown the locking of their own. They had their own homegrown rwsem, with lookup/readdir/atomic_open being *writers* (sillyunlink is the reader there). Of course, with VFS getting the fuck out of the way, as requested, the actual smarts of the smart filesystem code etc. had become exposed... - do_last/lookup_open/atomic_open cleanups. As the result, open() without O_CREAT locks the directory only shared. Including the ->atomic_open() case. Backmerge from #for-linus in the middle of that - atomic_open() fix got brought in. - then comes NFS switch to saner (VFS-based ;-) locking, killing the homegrown "lookup and readdir are writers" kinda-sorta rwsem. All exclusion for sillyunlink/lookup is done by the parallel lookups mechanism. Exclusion between sillyunlink and rmdir is a real rwsem now - rmdir being the writer. Result: NFS lookups/readdirs/O_CREAT-less opens happen in parallel now. - the rest of the series consists of switching a lot of filesystems to parallel readdir; in a lot of cases ->llseek() gets simplified as well. One backmerge in there (again, #for-linus - rockridge fix)" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (74 commits) ext4: switch to ->iterate_shared() hfs: switch to ->iterate_shared() hfsplus: switch to ->iterate_shared() hostfs: switch to ->iterate_shared() hpfs: switch to ->iterate_shared() hpfs: handle allocation failures in hpfs_add_pos() gfs2: switch to ->iterate_shared() f2fs: switch to ->iterate_shared() afs: switch to ->iterate_shared() befs: switch to ->iterate_shared() befs: constify stuff a bit isofs: switch to ->iterate_shared() get_acorn_filename(): deobfuscate a bit btrfs: switch to ->iterate_shared() logfs: no need to lock directory in lseek switch ecryptfs to ->iterate_shared 9p: switch to ->iterate_shared() fat: switch to ->iterate_shared() romfs, squashfs: switch to ->iterate_shared() more trivial ->iterate_shared conversions ...
2016-05-17Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds4-27/+65
Pull irq updates from Thomas Gleixner: "This update delivers: - Yet another interrupt chip diver (LPC32xx) - Core functions to handle partitioned per-cpu interrupts - Enhancements to the IPI core - Proper handling of irq type configuration - A large set of ARM GIC enhancements - The usual pile of small fixes, cleanups and enhancements" * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits) irqchip/bcm2836: Use a more generic memory barrier call irqchip/bcm2836: Fix compiler warning on 64-bit build irqchip/bcm2836: Drop smp_set_ops on arm64 builds irqchip/gic: Add helper functions for GIC setup and teardown irqchip/gic: Store GIC configuration parameters irqchip/gic: Pass GIC pointer to save/restore functions irqchip/gic: Return an error if GIC initialisation fails irqchip/gic: Remove static irq_chip definition for eoimode1 irqchip/gic: Don't initialise chip if mapping IO space fails irqchip/gic: WARN if setting the interrupt type for a PPI fails irqchip/gic: Don't unnecessarily write the IRQ configuration irqchip: Mask the non-type/sense bits when translating an IRQ genirq: Ensure IRQ descriptor is valid when setting-up the IRQ irqchip/gic-v3: Configure all interrupts as non-secure Group-1 irqchip/gic-v2m: Add workaround for Broadcom NS2 GICv2m erratum irqchip/irq-alpine-msi: Don't use <asm-generic/msi.h> irqchip/mbigen: Checking for IS_ERR() instead of NULL irqchip/gic-v3: Remove inexistant register definition irqchip/gicv3-its: Don't allow devices whose ID is outside range irqchip: Add LPC32xx interrupt controller driver ...
2016-05-17Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-4/+4
Pull timer updates from Thomas Gleixner: "A rather small set of patches from the timer departement: - Some more y2038 work - Yet another new clocksource driver - The usual set of small fixes, cleanups and enhancements" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: clocksource/drivers/tegra: Remove unused suspend/resume code clockevents/driversi/mps2: add MPS2 Timer driver dt-bindings: document the MPS2 timer bindings clocksource/drivers/mtk_timer: Add __init attribute clockevents/drivers/dw_apb_timer: Implement ->set_state_oneshot_stopped() time: Introduce do_sys_settimeofday64() security: Introduce security_settime64() clocksource: Add missing include of of.h.
2016-05-17Merge tag 'trace-fixes-v4.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-traceLinus Torvalds1-17/+18
Pull tracing ring-buffer fixes from Steven Rostedt: "Hao Qin reported an integer overflow possibility with signed and unsigned numbers in the ring-buffer code. https://bugzilla.kernel.org/show_bug.cgi?id=118001 At first I did not think this was too much of an issue, because the overflow would be caught later when either too much data was allocated or it would trigger RB_WARN_ON() which shuts down the ring buffer. But looking closer into it, I found that the right settings could bypass the checks and crash the kernel. Luckily, this is only accessible by root. The first fix is to convert all the variables into long, such that we don't get into issues between 32 bit variables being assigned 64 bit ones. This fixes the RB_WARN_ON() triggering. The next fix is to get rid of a duplicate DIV_ROUND_UP() that when called twice with the right value, can cause a kernel crash. The first DIV_ROUND_UP() is to normalize the input and it is checked against the minimum allowable value. But then DIV_ROUND_UP() is called again, which can overflow due to the (a + b - 1)/b, logic. The first called upped the value, the second can overflow (with the +b part). The second call to DIV_ROUND_UP() came in via a second change a while ago and the code is cleaned up to remove it" * tag 'trace-fixes-v4.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ring-buffer: Prevent overflow of size in ring_buffer_resize() ring-buffer: Use long for nr_pages to avoid overflow failures
2016-05-17Merge branches 'for-4.7/core', 'for-4.7/livepatching-doc' and 'for-4.7/livepatching-ppc64' into for-linusJiri Kosina3-64/+263
2016-05-17Merge branch 'ovl-fixes' into for-linusAl Viro18-95/+280
Backmerge to resolve a conflict in ovl_lookup_real(); "ovl_lookup_real(): use lookup_one_len_unlocked()" instead, but it was too late in the cycle to rebase.
2016-05-16Merge tag 'pm-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pmLinus Torvalds5-11/+577
Pull power management updates from Rafael Wysocki: "The majority of changes go into the cpufreq subsystem this time. To me, quite obviously, the biggest ticket item is the new "schedutil" governor. Interestingly enough, it's the first new cpufreq governor since the beginning of the git era (except for some out-of-the-tree ones). There are two main differences between it and the existing governors. First, it uses the information provided by the scheduler directly for making its decisions, so it doesn't have to track anything by itself. Second, it can invoke drivers (supporting that feature) to adjust CPU performance right away without having to spawn work items to be executed in process context or similar. Currently, the acpi-cpufreq driver is the only one supporting that mode of operation, but then it is used on a large number of systems. The "schedutil" governor as included here is very simple and mostly regarded as a foundation for future work on the integration of the scheduler with CPU power management (in fact, there is work in progress on top of it already). Nevertheless it works and the preliminary results obtained with it are encouraging. There also is some consolidation of CPU frequency management for ARM platforms that can add their machine IDs the the new stub dt-platdev driver now and that will take care of creating the requisite platform device for cpufreq-dt, so it is not necessary to do that in platform code any more. Several ARM platforms are switched over to using this generic mechanism. In addition to that, the intel_pstate driver is now going to respect CPU frequency limits set by the platform firmware (or a BMC) and provided via the ACPI _PPC object. The devfreq subsystem is getting a new "passive" governor for SoCs subsystems that will depend on somebody else to manage their voltage rails and its support for Samsung Exynos SoCs is consolidated. The rest is support for new hardware (Intel Broxton support in intel_idle for one example), bug fixes, optimizations and cleanups in a number of places. Specifics: - New cpufreq "schedutil" governor (making decisions based on CPU utilization information provided by the scheduler and capable of switching CPU frequencies right away if the underlying driver supports that) and support for fast frequency switching in the acpi-cpufreq driver (Rafael Wysocki) - Consolidation of CPU frequency management on ARM platforms allowing them to get rid of some platform-specific boilerplate code if they are going to use the cpufreq-dt driver (Viresh Kumar, Finley Xiao, Marc Gonzalez) - Support for ACPI _PPC and CPU frequency limits in the intel_pstate driver (Srinivas Pandruvada) - Fixes and cleanups in the cpufreq core and generic governor code (Rafael Wysocki, Sai Gurrappadi) - intel_pstate driver optimizations and cleanups (Rafael Wysocki, Philippe Longepe, Chen Yu, Joe Perches) - cpufreq powernv driver fixes and cleanups (Akshay Adiga, Shilpasri Bhat) - cpufreq qoriq driver fixes and cleanups (Jia Hongtao) - ACPI cpufreq driver cleanups (Viresh Kumar) - Assorted cpufreq driver updates (Ashwin Chaugule, Geliang Tang, Javier Martinez Canillas, Paul Gortmaker, Sudeep Holla) - Assorted cpufreq fixes and cleanups (Joe Perches, Arnd Bergmann) - Fixes and cleanups in the OPP (Operating Performance Points) framework, mostly related to OPP sharing, and reorganization of OF-dependent code in it (Viresh Kumar, Arnd Bergmann, Sudeep Holla) - New "passive" governor for devfreq (for SoC subsystems that will rely on someone else for the management of their power resources) and consolidation of devfreq support for Exynos platforms, coding style and typo fixes for devfreq (Chanwoo Choi, MyungJoo Ham) - PM core fixes and cleanups, mostly to make it work better with the generic power domains (genpd) framework, and updates for that framework (Ulf Hansson, Thierry Reding, Colin Ian King) - Intel Broxton support for the intel_idle driver (Len Brown) - cpuidle core optimization and fix (Daniel Lezcano, Dave Gerlach) - ARM cpuidle cleanups (Jisheng Zhang) - Intel Kabylake support for the RAPL power capping driver (Jacob Pan) - AVS (Adaptive Voltage Switching) rockchip-io driver update (Heiko Stuebner) - Updates for the cpupower tool (Arjun Sreedharan, Colin Ian King, Mattia Dongili, Thomas Renninger)" * tag 'pm-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (112 commits) intel_pstate: Clean up get_target_pstate_use_performance() intel_pstate: Use sample.core_avg_perf in get_avg_pstate() intel_pstate: Clarify average performance computation intel_pstate: Avoid unnecessary synchronize_sched() during initialization cpufreq: schedutil: Make default depend on CONFIG_SMP cpufreq: powernv: del_timer_sync when global and local pstate are equal cpufreq: powernv: Move smp_call_function_any() out of irq safe block intel_pstate: Clean up intel_pstate_get() cpufreq: schedutil: Make it depend on CONFIG_SMP cpufreq: governor: Fix handling of special cases in dbs_update() PM / OPP: Move CONFIG_OF dependent code in a separate file cpufreq: intel_pstate: Ignore _PPC processing under HWP cpufreq: arm_big_little: use generic OPP functions for {init, free}_opp_table PM / OPP: add non-OF versions of dev_pm_opp_{cpumask_, }remove_table cpufreq: tango: Use generic platdev driver PM / OPP: pass cpumask by reference cpufreq: Fix GOV_LIMITS handling for the userspace governor cpupower: fix potential memory leak PM / devfreq: style/typo fixes PM / devfreq: exynos: Add the detailed correlation for Exynos5422 bus ..
2016-05-16Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linuxLinus Torvalds1-0/+18
Pull arm64 updates from Will Deacon: - virt_to_page/page_address optimisations - support for NUMA systems described using device-tree - support for hibernate/suspend-to-disk - proper support for maxcpus= command line parameter - detection and graceful handling of AArch64-only CPUs - miscellaneous cleanups and non-critical fixes * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (92 commits) arm64: do not enforce strict 16 byte alignment to stack pointer arm64: kernel: Fix incorrect brk randomization arm64: cpuinfo: Missing NULL terminator in compat_hwcap_str arm64: secondary_start_kernel: Remove unnecessary barrier arm64: Ensure pmd_present() returns false after pmd_mknotpresent() arm64: Replace hard-coded values in the pmd/pud_bad() macros arm64: Implement pmdp_set_access_flags() for hardware AF/DBM arm64: Fix typo in the pmdp_huge_get_and_clear() definition arm64: mm: remove unnecessary EXPORT_SYMBOL_GPL arm64: always use STRICT_MM_TYPECHECKS arm64: kvm: Fix kvm teardown for systems using the extended idmap arm64: kaslr: increase randomization granularity arm64: kconfig: drop CONFIG_RTC_LIB dependency arm64: make ARCH_SUPPORTS_DEBUG_PAGEALLOC depend on !HIBERNATION arm64: hibernate: Refuse to hibernate if the boot cpu is offline arm64: kernel: Add support for hibernate/suspend-to-disk PM / Hibernate: Call flush_icache_range() on pages restored in-place arm64: Add new asm macro copy_page arm64: Promote KERNEL_START/KERNEL_END definitions to a header file arm64: kernel: Include _AC definition in page.h ...
2016-05-16Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds16-776/+1059
Pull scheduler updates from Ingo Molnar: - massive CPU hotplug rework (Thomas Gleixner) - improve migration fairness (Peter Zijlstra) - CPU load calculation updates/cleanups (Yuyang Du) - cpufreq updates (Steve Muckle) - nohz optimizations (Frederic Weisbecker) - switch_mm() micro-optimization on x86 (Andy Lutomirski) - ... lots of other enhancements, fixes and cleanups. * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (66 commits) ARM: Hide finish_arch_post_lock_switch() from modules sched/core: Provide a tsk_nr_cpus_allowed() helper sched/core: Use tsk_cpus_allowed() instead of accessing ->cpus_allowed sched/loadavg: Fix loadavg artifacts on fully idle and on fully loaded systems sched/fair: Correct unit of load_above_capacity sched/fair: Clean up scale confusion sched/nohz: Fix affine unpinned timers mess sched/fair: Fix fairness issue on migration sched/core: Kill sched_class::task_waking to clean up the migration logic sched/fair: Prepare to fix fairness problems on migration sched/fair: Move record_wakee() sched/core: Fix comment typo in wake_q_add() sched/core: Remove unused variable sched: Make hrtick_notifier an explicit call sched/fair: Make ilb_notifier an explicit call sched/hotplug: Make activate() the last hotplug step sched/hotplug: Move migration CPU_DYING to sched_cpu_dying() sched/migration: Move CPU_ONLINE into scheduler state sched/migration: Move calc_load_migrate() into CPU_DYING sched/migration: Move prepare transition to SCHED_STARTING state ...
2016-05-16Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds7-92/+1005
Pull perf updates from Ingo Molnar: "Bigger kernel side changes: - Add backwards writing capability to the perf ring-buffer code, which is preparation for future advanced features like robust 'overwrite support' and snapshot mode. (Wang Nan) - Add pause and resume ioctls for the perf ringbuffer (Wang Nan) - x86 Intel cstate code cleanups and reorgnization (Thomas Gleixner) - x86 Intel uncore and CPU PMU driver updates (Kan Liang, Peter Zijlstra) - x86 AUX (Intel PT) related enhancements and updates (Alexander Shishkin) - x86 MSR PMU driver enhancements and updates (Huang Rui) - ... and lots of other changes spread out over 40+ commits. Biggest tooling side changes: - 'perf trace' features and enhancements. (Arnaldo Carvalho de Melo) - BPF tooling updates (Wang Nan) - 'perf sched' updates (Jiri Olsa) - 'perf probe' updates (Masami Hiramatsu) - ... plus 200+ other enhancements, fixes and cleanups to tools/ The merge commits, the shortlog and the changelogs contain a lot more details" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (249 commits) perf/core: Disable the event on a truncated AUX record perf/x86/intel/pt: Generate PMI in the STOP region as well perf buildid-cache: Use lsdir() for looking up buildid caches perf symbols: Use lsdir() for the search in kcore cache directory perf tools: Use SBUILD_ID_SIZE where applicable perf tools: Fix lsdir to set errno correctly perf trace: Move seccomp args beautifiers to tools/perf/trace/beauty/ perf trace: Move flock op beautifier to tools/perf/trace/beauty/ perf build: Add build-test for debug-frame on arm/arm64 perf build: Add build-test for libunwind cross-platforms support perf script: Fix export of callchains with recursion in db-export perf script: Fix callchain addresses in db-export perf script: Fix symbol insertion behavior in db-export perf symbols: Add dso__insert_symbol function perf scripting python: Use Py_FatalError instead of die() perf tools: Remove xrealloc and ALLOC_GROW perf help: Do not use ALLOC_GROW in add_cmd_list perf pmu: Make pmu_formats_string to check return value of strbuf perf header: Make topology checkers to check return value of strbuf perf tools: Make alias handler to check return value of strbuf ...
2016-05-16Merge branch 'locking-rwsem-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds3-8/+68
Pull support for killable rwsems from Ingo Molnar: "This, by Michal Hocko, implements down_write_killable(). The main usecase will be to update mm_sem usage sites to use this new API, to allow the mm-reaper introduced in commit aac453635549 ("mm, oom: introduce oom reaper") to tear down oom victim address spaces asynchronously with minimum latencies and without deadlock worries" [ The vfs will want it too as the inode lock is changed from a mutex to a rwsem due to the parallel lookup and readdir updates ] * 'locking-rwsem-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: locking/rwsem: Fix comment on register clobbering locking/rwsem: Fix down_write_killable() locking/rwsem, x86: Add frame annotation for call_rwsem_down_write_failed_killable() locking/rwsem: Provide down_write_killable() locking/rwsem, x86: Provide __down_write_killable() locking/rwsem, s390: Provide __down_write_killable() locking/rwsem, ia64: Provide __down_write_killable() locking/rwsem, alpha: Provide __down_write_killable() locking/rwsem: Introduce basis for down_write_killable() locking/rwsem, sparc: Drop superfluous arch specific implementation locking/rwsem, sh: Drop superfluous arch specific implementation locking/rwsem, xtensa: Drop superfluous arch specific implementation locking/rwsem: Drop explicit memory barriers locking/rwsem: Get rid of __down_write_nested()
2016-05-16Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds4-22/+33
Pull locking changes from Ingo Molnar: "The main changes in this cycle were: - pvqspinlock statistics fixes (Davidlohr Bueso) - flip atomic_fetch_or() arguments (Peter Zijlstra) - locktorture simplification (Paul E. McKenney) - documentation updates (SeongJae Park, David Howells, Davidlohr Bueso, Paul E McKenney, Peter Zijlstra, Will Deacon) - various fixes" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: locking/atomics: Flip atomic_fetch_or() arguments locking/pvqspinlock: Robustify init_qspinlock_stat() locking/pvqspinlock: Avoid double resetting of stats lcoking/locktorture: Simplify the torture_runnable computation locking/Documentation: Clarify that ACQUIRE applies to loads, RELEASE applies to stores locking/Documentation: State purpose of memory-barriers.txt locking/Documentation: Add disclaimer locking/Documentation/lockdep: Fix spelling mistakes locking/lockdep: Deinline register_lock_class(), save 2328 bytes locking/locktorture: Fix NULL pointer dereference for cleanup paths locking/locktorture: Fix deboosting NULL pointer dereference locking/Documentation: Mention smp_cond_acquire() locking/Documentation: Insert white spaces consistently locking/Documentation: Fix formatting inconsistencies locking/Documentation: Add missed subsection in TOC locking/Documentation: Fix missed s/lock/acquire renames locking/Documentation: Clarify relationship of barrier() to control dependencies
2016-05-16Merge branch 'core-signals-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds2-14/+17
Pull core signal updates from Ingo Molnar: "These updates from Stas Sergeev and Andy Lutomirski, improve the sigaltstack interface by extending its ABI with the SS_AUTODISARM feature, which makes it possible to use swapcontext() in a sighandler that works on sigaltstack. Without this flag, the subsequent signal will corrupt the state of the switched-away sighandler. The inspiration is more robust dosemu signal handling" * 'core-signals-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: signals/sigaltstack: Change SS_AUTODISARM to (1U << 31) signals/sigaltstack: Report current flag bits in sigaltstack() selftests/sigaltstack: Fix the sigaltstack test on old kernels signals/sigaltstack: If SS_AUTODISARM, bypass on_sig_stack() selftests/sigaltstack: Add new testcase for sigaltstack(SS_ONSTACK|SS_AUTODISARM) signals/sigaltstack: Implement SS_AUTODISARM flag signals/sigaltstack: Prepare to add new SS_xxx flags signals/sigaltstack, x86/signals: Unify the x86 sigaltstack check with other architectures
2016-05-16Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds9-149/+916
Pull RCU updates from Ingo Molnar: "The main changes are: - Documentation updates, including fixes to the design-level requirements documentation and a fixed version of the design-level data-structure documentation. These fixes include removing cartoons and getting rid of the html/htmlx duplication. - Further improvements to the new-age expedited grace periods. - Miscellaneous fixes. - Torture-test changes, including a new rcuperf module for measuring RCU grace-period performance and scalability, which is useful for the expedited-grace-period changes" * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (56 commits) rcutorture: Add boot-time adjustment of leaf fanout rcutorture: Add irqs-disabled test for call_rcu() rcutorture: Dump trace buffer upon shutdown rcutorture: Don't rebuild identical kernel rcutorture: Add OS-jitter capability documentation: Add documentation for RCU's major data structures rcutorture: Convert test duration to seconds early torture: Kill qemu, not parent process torture: Clarify refusal to run more than one torture test rcutorture: Consider FROZEN hotplug notifier transitions rcutorture: Remove redundant initialization to zero rcuperf: Do not wake up shutdown wait queue if "shutdown" is false. rcutorture: Add largish-system rcuperf scenario rcutorture: Avoid RCU CPU stall warning and RT throttling rcutorture: Add rcuperf holdoff boot parameter to reduce interference rcutorture: Make scripts analyze rcuperf trace data, if present rcutorture: Make rcuperf collect expedited event-trace data rcutorture: Print measure of batching efficiency rcutorture: Set rcuperf writer kthreads to real-time priority rcutorture: Bind rcuperf reader/writer kthreads to CPUs ...
2016-05-16bpf: add generic constant blinding for use in jitsDaniel Borkmann1-0/+203
This work adds a generic facility for use from eBPF JIT compilers that allows for further hardening of JIT generated images through blinding constants. In response to the original work on BPF JIT spraying published by Keegan McAllister [1], most BPF JITs were changed to make images read-only and start at a randomized offset in the page, where the rest was filled with trap instructions. We have this nowadays in x86, arm, arm64 and s390 JIT compilers. Additionally, later work also made eBPF interpreter images read only for kernels supporting DEBUG_SET_MODULE_RONX, that is, x86, arm, arm64 and s390 archs as well currently. This is done by default for mentioned JITs when JITing is enabled. Furthermore, we had a generic and configurable constant blinding facility on our todo for quite some time now to further make spraying harder, and first implementation since around netconf 2016. We found that for systems where untrusted users can load cBPF/eBPF code where JIT is enabled, start offset randomization helps a bit to make jumps into crafted payload harder, but in case where larger programs that cross page boundary are injected, we again have some part of the program opcodes at a page start offset. With improved guessing and more reliable payload injection, chances can increase to jump into such payload. Elena Reshetova recently wrote a test case for it [2, 3]. Moreover, eBPF comes with 64 bit constants, which can leave some more room for payloads. Note that for all this, additional bugs in the kernel are still required to make the jump (and of course to guess right, to not jump into a trap) and naturally the JIT must be enabled, which is disabled by default. For helping mitigation, the general idea is to provide an option bpf_jit_harden that admins can tweak along with bpf_jit_enable, so that for cases where JIT should be enabled for performance reasons, the generated image can be further hardened with blinding constants for unpriviledged users (bpf_jit_harden == 1), with trading off performance for these, but not for privileged ones. We also added the option of blinding for all users (bpf_jit_harden == 2), which is quite helpful for testing f.e. with test_bpf.ko. There are no further e.g. hardening levels of bpf_jit_harden switch intended, rationale is to have it dead simple to use as on/off. Since this functionality would need to be duplicated over and over for JIT compilers to use, which are already complex enough, we provide a generic eBPF byte-code level based blinding implementation, which is then just transparently JITed. JIT compilers need to make only a few changes to integrate this facility and can be migrated one by one. This option is for eBPF JITs and will be used in x86, arm64, s390 without too much effort, and soon ppc64 JITs, thus that native eBPF can be blinded as well as cBPF to eBPF migrations, so that both can be covered with a single implementation. The rule for JITs is that bpf_jit_blind_constants() must be called from bpf_int_jit_compile(), and in case blinding is disabled, we follow normally with JITing the passed program. In case blinding is enabled and we fail during the process of blinding itself, we must return with the interpreter. Similarly, in case the JITing process after the blinding failed, we return normally to the interpreter with the non-blinded code. Meaning, interpreter doesn't change in any way and operates on eBPF code as usual. For doing this pre-JIT blinding step, we need to make use of a helper/auxiliary register, here BPF_REG_AX. This is strictly internal to the JIT and not in any way part of the eBPF architecture. Just like in the same way as JITs internally make use of some helper registers when emitting code, only that here the helper register is one abstraction level higher in eBPF bytecode, but nevertheless in JIT phase. That helper register is needed since f.e. manually written program can issue loads to all registers of eBPF architecture. The core concept with the additional register is: blind out all 32 and 64 bit constants by converting BPF_K based instructions into a small sequence from K_VAL into ((RND ^ K_VAL) ^ RND). Therefore, this is transformed into: BPF_REG_AX := (RND ^ K_VAL), BPF_REG_AX ^= RND, and REG <OP> BPF_REG_AX, so actual operation on the target register is translated from BPF_K into BPF_X one that is operating on BPF_REG_AX's content. During rewriting phase when blinding, RND is newly generated via prandom_u32() for each processed instruction. 64 bit loads are split into two 32 bit loads to make translation and patching not too complex. Only basic thing required by JITs is to call the helper bpf_jit_blind_constants()/bpf_jit_prog_release_other() pair, and to map BPF_REG_AX into an unused register. Small bpf_jit_disasm extract from [2] when applied to x86 JIT: echo 0 > /proc/sys/net/core/bpf_jit_harden ffffffffa034f5e9 + <x>: [...] 39: mov $0xa8909090,%eax 3e: mov $0xa8909090,%eax 43: mov $0xa8ff3148,%eax 48: mov $0xa89081b4,%eax 4d: mov $0xa8900bb0,%eax 52: mov $0xa810e0c1,%eax 57: mov $0xa8908eb4,%eax 5c: mov $0xa89020b0,%eax [...] echo 1 > /proc/sys/net/core/bpf_jit_harden ffffffffa034f1e5 + <x>: [...] 39: mov $0xe1192563,%r10d 3f: xor $0x4989b5f3,%r10d 46: mov %r10d,%eax 49: mov $0xb8296d93,%r10d 4f: xor $0x10b9fd03,%r10d 56: mov %r10d,%eax 59: mov $0x8c381146,%r10d 5f: xor $0x24c7200e,%r10d 66: mov %r10d,%eax 69: mov $0xeb2a830e,%r10d 6f: xor $0x43ba02ba,%r10d 76: mov %r10d,%eax 79: mov $0xd9730af,%r10d 7f: xor $0xa5073b1f,%r10d 86: mov %r10d,%eax 89: mov $0x9a45662b,%r10d 8f: xor $0x325586ea,%r10d 96: mov %r10d,%eax [...] As can be seen, original constants that carry payload are hidden when enabled, actual operations are transformed from constant-based to register-based ones, making jumps into constants ineffective. Above extract/example uses single BPF load instruction over and over, but of course all instructions with constants are blinded. Performance wise, JIT with blinding performs a bit slower than just JIT and faster than interpreter case. This is expected, since we still get all the performance benefits from JITing and in normal use-cases not every single instruction needs to be blinded. Summing up all 296 test cases averaged over multiple runs from test_bpf.ko suite, interpreter was 55% slower than JIT only and JIT with blinding was 8% slower than JIT only. Since there are also some extremes in the test suite, I expect for ordinary workloads that the performance for the JIT with blinding case is even closer to JIT only case, f.e. nmap test case from suite has averaged timings in ns 29 (JIT), 35 (+ blinding), and 151 (interpreter). BPF test suite, seccomp test suite, eBPF sample code and various bigger networking eBPF programs have been tested with this and were running fine. For testing purposes, I also adapted interpreter and redirected blinded eBPF image to interpreter and also here all tests pass. [1] http://mainisusuallyafunction.blogspot.com/2012/11/attacking-hardened-linux-systems-with.html [2] https://github.com/01org/jit-spray-poc-for-ksp/ [3] http://www.openwall.com/lists/kernel-hardening/2016/05/03/5 Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Elena Reshetova <elena.reshetova@intel.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-16bpf: prepare bpf_int_jit_compile/bpf_prog_select_runtime apisDaniel Borkmann2-5/+15
Since the blinding is strictly only called from inside eBPF JITs, we need to change signatures for bpf_int_jit_compile() and bpf_prog_select_runtime() first in order to prepare that the eBPF program we're dealing with can change underneath. Hence, for call sites, we need to return the latest prog. No functional change in this patch. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-16bpf: add bpf_patch_insn_single helperDaniel Borkmann2-44/+80
Move the functionality to patch instructions out of the verifier code and into the core as the new bpf_patch_insn_single() helper will be needed later on for blinding as well. No changes in functionality. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-16bpf: minor cleanups in ebpf codeDaniel Borkmann1-2/+0
Besides others, remove redundant comments where the code is self documenting enough, and properly indent various bpf_verifier_ops and bpf_prog_type_list declarations. Moreover, remove two exports that actually have no module user. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-16Merge branch 'pm-cpufreq'Rafael J. Wysocki5-11/+577
* pm-cpufreq: (63 commits) intel_pstate: Clean up get_target_pstate_use_performance() intel_pstate: Use sample.core_avg_perf in get_avg_pstate() intel_pstate: Clarify average performance computation intel_pstate: Avoid unnecessary synchronize_sched() during initialization cpufreq: schedutil: Make default depend on CONFIG_SMP cpufreq: powernv: del_timer_sync when global and local pstate are equal cpufreq: powernv: Move smp_call_function_any() out of irq safe block intel_pstate: Clean up intel_pstate_get() cpufreq: schedutil: Make it depend on CONFIG_SMP cpufreq: governor: Fix handling of special cases in dbs_update() cpufreq: intel_pstate: Ignore _PPC processing under HWP cpufreq: arm_big_little: use generic OPP functions for {init, free}_opp_table cpufreq: tango: Use generic platdev driver cpufreq: Fix GOV_LIMITS handling for the userspace governor cpufreq: mvebu: Move cpufreq code into drivers/cpufreq/ cpufreq: dt: Kill platform-data mvebu: Use dev_pm_opp_set_sharing_cpus() to mark OPP tables as shared cpufreq: dt: Identify cpu-sharing for platforms without operating-points-v2 cpufreq: governor: Change confusing struct field and variable names cpufreq: intel_pstate: Enable PPC enforcement for servers ...
2016-05-15locking/rwsem: Fix down_write_killable()Peter Zijlstra1-6/+15
The new signal_pending exit path in __rwsem_down_write_failed_common() was fingered as breaking his kernel by Tetsuo Handa. Upon inspection it was found that there are two things wrong with it; - it forgets to remove WAITING_BIAS if it leaves the list empty, or - it forgets to wake further waiters that were blocked on the now removed waiter. Especially the first issue causes new lock attempts to block and stall indefinitely, as the code assumes that pending waiters mean there is an owner that will wake when it releases the lock. Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Tested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Tested-by: Michal Hocko <mhocko@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Chris Zankel <chris@zankel.net> Cc: David S. Miller <davem@davemloft.net> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Waiman Long <Waiman.Long@hpe.com> Link: http://lkml.kernel.org/r/20160512115745.GP3192@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller7-17/+100
The nf_conntrack_core.c fix in 'net' is not relevant in 'net-next' because we no longer have a per-netns conntrack hash. The ip_gre.c conflict as well as the iwlwifi ones were cases of overlapping changes. Conflicts: drivers/net/wireless/intel/iwlwifi/mvm/tx.c net/ipv4/ip_gre.c net/netfilter/nf_conntrack_core.c Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-13Merge branch 'for-4.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroupLinus Torvalds1-0/+63
Pull cgroup fixes from Tejun Heo: "During v4.6-rc1 cgroup namespace support was merged. There is an issue where it's impossible to tell whether a given cgroup mount point is bind mounted or namespaced. Serge has been working on the issue but it took longer than expected to resolve, so the late pull request. Given that it's a completely new feature and the patches don't touch anything else, the risk seems acceptable. However, if this is too late, an alternative is plugging new cgroup ns creation for v4.6 and retrying for v4.7" * 'for-4.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: fix compile warning kernfs: kernfs_sop_show_path: don't return 0 after seq_dentry call cgroup, kernfs: make mountinfo show properly scoped path for cgroup namespaces kernfs_path_from_node_locked: don't overwrite nlen
2016-05-13Merge branch 'for-4.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds1-0/+11
Pull workqueue fix from Tejun Heo: "CPU hotplug callbacks can invoke DOWN_FAILED w/o preceding DOWN_PREPARE which can trigger a WARN_ON() in workqueue. The bug has been there for a very long time. It only triggers if CPU down fails at a specific point and I don't think it has adverse effects other than the warning messages. The fix is very low impact" * 'for-4.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: fix rebind bound workers warning
2016-05-13ring-buffer: Prevent overflow of size in ring_buffer_resize()Steven Rostedt (Red Hat)1-5/+4
If the size passed to ring_buffer_resize() is greater than MAX_LONG - BUF_PAGE_SIZE then the DIV_ROUND_UP() will return zero. Here's the details: # echo 18014398509481980 > /sys/kernel/debug/tracing/buffer_size_kb tracing_entries_write() processes this and converts kb to bytes. 18014398509481980 << 10 = 18446744073709547520 and this is passed to ring_buffer_resize() as unsigned long size. size = DIV_ROUND_UP(size, BUF_PAGE_SIZE); Where DIV_ROUND_UP(a, b) is (a + b - 1)/b BUF_PAGE_SIZE is 4080 and here 18446744073709547520 + 4080 - 1 = 18446744073709551599 where 18446744073709551599 is still smaller than 2^64 2^64 - 18446744073709551599 = 17 But now 18446744073709551599 / 4080 = 4521260802379792 and size = size * 4080 = 18446744073709551360 This is checked to make sure its still greater than 2 * 4080, which it is. Then we convert to the number of buffer pages needed. nr_page = DIV_ROUND_UP(size, BUF_PAGE_SIZE) but this time size is 18446744073709551360 and 2^64 - (18446744073709551360 + 4080 - 1) = -3823 Thus it overflows and the resulting number is less than 4080, which makes 3823 / 4080 = 0 an nr_pages is set to this. As we already checked against the minimum that nr_pages may be, this causes the logic to fail as well, and we crash the kernel. There's no reason to have the two DIV_ROUND_UP() (that's just result of historical code changes), clean up the code and fix this bug. Cc: stable@vger.kernel.org # 3.5+ Fixes: 83f40318dab00 ("ring-buffer: Make removal of ring buffer pages atomic") Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-05-13Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-14/+6
Pull scheduler fix from Ingo Molnar: "This is a revert to fix an interactivity problem. The proper fixes for the problems that the reverted commit exposed are now in sched/core (consisting of 3 patches), but were too risky for v4.6 and will arrive in the v4.7 merge window" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: Revert "sched/fair: Fix fairness issue on migration"
2016-05-13ring-buffer: Use long for nr_pages to avoid overflow failuresSteven Rostedt (Red Hat)1-12/+14
The size variable to change the ring buffer in ftrace is a long. The nr_pages used to update the ring buffer based on the size is int. On 64 bit machines this can cause an overflow problem. For example, the following will cause the ring buffer to crash: # cd /sys/kernel/debug/tracing # echo 10 > buffer_size_kb # echo 8556384240 > buffer_size_kb Then you get the warning of: WARNING: CPU: 1 PID: 318 at kernel/trace/ring_buffer.c:1527 rb_update_pages+0x22f/0x260 Which is: RB_WARN_ON(cpu_buffer, nr_removed); Note each ring buffer page holds 4080 bytes. This is because: 1) 10 causes the ring buffer to have 3 pages. (10kb requires 3 * 4080 pages to hold) 2) (2^31 / 2^10 + 1) * 4080 = 8556384240 The value written into buffer_size_kb is shifted by 10 and then passed to ring_buffer_resize(). 8556384240 * 2^10 = 8761737461760 3) The size passed to ring_buffer_resize() is then divided by BUF_PAGE_SIZE which is 4080. 8761737461760 / 4080 = 2147484672 4) nr_pages is subtracted from the current nr_pages (3) and we get: 2147484669. This value is saved in a signed integer nr_pages_to_update 5) 2147484669 is greater than 2^31 but smaller than 2^32, a signed int turns into the value of -2147482627 6) As the value is a negative number, in update_pages_handler() it is negated and passed to rb_remove_pages() and 2147482627 pages will be removed, which is much larger than 3 and it causes the warning because not all the pages asked to be removed were removed. Link: https://bugzilla.kernel.org/show_bug.cgi?id=118001 Cc: stable@vger.kernel.org # 2.6.28+ Fixes: 7a8e76a3829f1 ("tracing: unified trace buffer") Reported-by: Hao Qin <QEver.cn@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-05-13secomp: Constify mode1 syscall whitelistMatt Redfearn1-2/+2
These values are constant and should be marked as such. Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Will Drewry <wad@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: IMG-MIPSLinuxKerneldevelopers@imgtec.com Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/12979/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13seccomp: Get compat syscalls from asm-generic headerMatt Redfearn1-8/+1
Move retrieval of compat syscall numbers into inline function defined in asm-generic header so that arches may override it. [ralf@linux-mips.org: Resolve merge conflict.] Suggested-by: Paul Burton <paul.burton@imgtec.com> Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: IMG-MIPSLinuxKerneldevelopers@imgtec.com Cc: Arnd Bergmann <arnd@arndb.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Will Drewry <wad@chromium.org> Cc: linux-arch@vger.kernel.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/12978/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-12workqueue: fix rebind bound workers warningWanpeng Li1-0/+11
------------[ cut here ]------------ WARNING: CPU: 0 PID: 16 at kernel/workqueue.c:4559 rebind_workers+0x1c0/0x1d0 Modules linked in: CPU: 0 PID: 16 Comm: cpuhp/0 Not tainted 4.6.0-rc4+ #31 Hardware name: IBM IBM System x3550 M4 Server -[7914IUW]-/00Y8603, BIOS -[D7E128FUS-1.40]- 07/23/2013 0000000000000000 ffff881037babb58 ffffffff8139d885 0000000000000010 0000000000000000 0000000000000000 0000000000000000 ffff881037babba8 ffffffff8108505d ffff881037ba0000 000011cf3e7d6e60 0000000000000046 Call Trace: dump_stack+0x89/0xd4 __warn+0xfd/0x120 warn_slowpath_null+0x1d/0x20 rebind_workers+0x1c0/0x1d0 workqueue_cpu_up_callback+0xf5/0x1d0 notifier_call_chain+0x64/0x90 ? trace_hardirqs_on_caller+0xf2/0x220 ? notify_prepare+0x80/0x80 __raw_notifier_call_chain+0xe/0x10 __cpu_notify+0x35/0x50 notify_down_prepare+0x5e/0x80 ? notify_prepare+0x80/0x80 cpuhp_invoke_callback+0x73/0x330 ? __schedule+0x33e/0x8a0 cpuhp_down_callbacks+0x51/0xc0 cpuhp_thread_fun+0xc1/0xf0 smpboot_thread_fn+0x159/0x2a0 ? smpboot_create_threads+0x80/0x80 kthread+0xef/0x110 ? wait_for_completion+0xf0/0x120 ? schedule_tail+0x35/0xf0 ret_from_fork+0x22/0x50 ? __init_kthread_worker+0x70/0x70 ---[ end trace eb12ae47d2382d8f ]--- notify_down_prepare: attempt to take down CPU 0 failed This bug can be reproduced by below config w/ nohz_full= all cpus: CONFIG_BOOTPARAM_HOTPLUG_CPU0=y CONFIG_DEBUG_HOTPLUG_CPU0=y CONFIG_NO_HZ_FULL=y As Thomas pointed out: | If a down prepare callback fails, then DOWN_FAILED is invoked for all | callbacks which have successfully executed DOWN_PREPARE. | | But, workqueue has actually two notifiers. One which handles | UP/DOWN_FAILED/ONLINE and one which handles DOWN_PREPARE. | | Now look at the priorities of those callbacks: | | CPU_PRI_WORKQUEUE_UP = 5 | CPU_PRI_WORKQUEUE_DOWN = -5 | | So the call order on DOWN_PREPARE is: | | CB 1 | CB ... | CB workqueue_up() -> Ignores DOWN_PREPARE | CB ... | CB X ---> Fails | | So we call up to CB X with DOWN_FAILED | | CB 1 | CB ... | CB workqueue_up() -> Handles DOWN_FAILED | CB ... | CB X-1 | | So the problem is that the workqueue stuff handles DOWN_FAILED in the up | callback, while it should do it in the down callback. Which is not a good idea | either because it wants to be called early on rollback... | | Brilliant stuff, isn't it? The hotplug rework will solve this problem because | the callbacks become symetric, but for the existing mess, we need some | workaround in the workqueue code. The boot CPU handles housekeeping duty(unbound timers, workqueues, timekeeping, ...) on behalf of full dynticks CPUs. It must remain online when nohz full is enabled. There is a priority set to every notifier_blocks: workqueue_cpu_up > tick_nohz_cpu_down > workqueue_cpu_down So tick_nohz_cpu_down callback failed when down prepare cpu 0, and notifier_blocks behind tick_nohz_cpu_down will not be called any more, which leads to workers are actually not unbound. Then hotplug state machine will fallback to undo and online cpu 0 again. Workers will be rebound unconditionally even if they are not unbound and trigger the warning in this progress. This patch fix it by catching !DISASSOCIATED to avoid rebind bound workers. Cc: Tejun Heo <tj@kernel.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Frédéric Weisbecker <fweisbec@gmail.com> Cc: stable@vger.kernel.org Suggested-by: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
2016-05-12cgroup: fix compile warningFelipe Balbi1-1/+1
commit 4f41fc59620f ("cgroup, kernfs: make mountinfo show properly scoped path for cgroup namespaces") added the following compile warning: kernel/cgroup.c: In function ‘cgroup_show_path’: kernel/cgroup.c:1634:15: warning: unused variable ‘ret’ [-Wunused-variable] int len = 0, ret = 0; ^ fix it. Fixes: 4f41fc59620f ("cgroup, kernfs: make mountinfo show properly scoped path for cgroup namespaces") Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2016-05-12perf/core: Disable the event on a truncated AUX recordAlexander Shishkin1-1/+9
When the PMU driver reports a truncated AUX record, it effectively means that there is no more usable room in the event's AUX buffer (even though there may still be some room, so that perf_aux_output_begin() doesn't take action). At this point the consumer still has to be woken up and the event has to be disabled, otherwise the event will just keep spinning between perf_aux_output_begin() and perf_aux_output_end() until its context gets unscheduled. Again, for cpu-wide events this means never, so once in this condition, they will be forever losing data. Fix this by disabling the event and waking up the consumer in case of a truncated AUX record. Reported-by: Markus Metzger <markus.t.metzger@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <stable@vger.kernel.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: vince@deater.net Link: http://lkml.kernel.org/r/1462886313-13660-3-git-send-email-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-12perf/core: Disable the event on a truncated AUX recordAlexander Shishkin1-1/+9
When the PMU driver reports a truncated AUX record, it effectively means that there is no more usable room in the event's AUX buffer (even though there may still be some room, so that perf_aux_output_begin() doesn't take action). At this point the consumer still has to be woken up and the event has to be disabled, otherwise the event will just keep spinning between perf_aux_output_begin() and perf_aux_output_end() until its context gets unscheduled. Again, for cpu-wide events this means never, so once in this condition, they will be forever losing data. Fix this by disabling the event and waking up the consumer in case of a truncated AUX record. Reported-by: Markus Metzger <markus.t.metzger@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: vince@deater.net Link: http://lkml.kernel.org/r/1462886313-13660-3-git-send-email-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-12sched/core: Provide a tsk_nr_cpus_allowed() helperThomas Gleixner3-27/+27
tsk_nr_cpus_allowed() is an accessor for task->nr_cpus_allowed which allows us to change the representation of ->nr_cpus_allowed if required. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1462969411-17735-2-git-send-email-bigeasy@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-12sched/core: Use tsk_cpus_allowed() instead of accessing ->cpus_allowedThomas Gleixner3-5/+5
Use the future-safe accessor for struct task_struct's. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1462969411-17735-1-git-send-email-bigeasy@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-12sched/loadavg: Fix loadavg artifacts on fully idle and on fully loaded systemsVik Heyndrickx1-4/+7
Systems show a minimal load average of 0.00, 0.01, 0.05 even when they have no load at all. Uptime and /proc/loadavg on all systems with kernels released during the last five years up until kernel version 4.6-rc5, show a 5- and 15-minute minimum loadavg of 0.01 and 0.05 respectively. This should be 0.00 on idle systems, but the way the kernel calculates this value prevents it from getting lower than the mentioned values. Likewise but not as obviously noticeable, a fully loaded system with no processes waiting, shows a maximum 1/5/15 loadavg of 1.00, 0.99, 0.95 (multiplied by number of cores). Once the (old) load becomes 93 or higher, it mathematically can never get lower than 93, even when the active (load) remains 0 forever. This results in the strange 0.00, 0.01, 0.05 uptime values on idle systems. Note: 93/2048 = 0.0454..., which rounds up to 0.05. It is not correct to add a 0.5 rounding (=1024/2048) here, since the result from this function is fed back into the next iteration again, so the result of that +0.5 rounding value then gets multiplied by (2048-2037), and then rounded again, so there is a virtual "ghost" load created, next to the old and active load terms. By changing the way the internally kept value is rounded, that internal value equivalent now can reach 0.00 on idle, and 1.00 on full load. Upon increasing load, the internally kept load value is rounded up, when the load is decreasing, the load value is rounded down. The modified code was tested on nohz=off and nohz kernels. It was tested on vanilla kernel 4.6-rc5 and on centos 7.1 kernel 3.10.0-327. It was tested on single, dual, and octal cores system. It was tested on virtual hosts and bare hardware. No unwanted effects have been observed, and the problems that the patch intended to fix were indeed gone. Tested-by: Damien Wyart <damien.wyart@free.fr> Signed-off-by: Vik Heyndrickx <vik.heyndrickx@veribox.net> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <stable@vger.kernel.org> Cc: Doug Smythies <dsmythies@telus.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 0f004f5a696a ("sched: Cure more NO_HZ load average woes") Link: http://lkml.kernel.org/r/e8d32bff-d544-7748-72b5-3c86cc71f09f@veribox.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-12sched/fair: Correct unit of load_above_capacityMorten Rasmussen1-2/+4
In calculate_imbalance() load_above_capacity currently has the unit [capacity] while it is used as being [load/capacity]. Not only is it wrong it also makes it unlikely that load_above_capacity is ever used as the subsequent code picks the smaller of load_above_capacity and the avg_load This patch ensures that load_above_capacity has the right unit [load/capacity]. Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com> [ Changed changelog to note it was in capacity unit; +rebase. ] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1461958364-675-4-git-send-email-dietmar.eggemann@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-12sched/fair: Clean up scale confusionPeter Zijlstra1-2/+1
Wanpeng noted that the scale_load_down() in calculate_imbalance() was weird. I agree, it should be SCHED_CAPACITY_SCALE, since we're going to compare against busiest->group_capacity, which is in [capacity] units. Reported-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Morten Rasmussen <morten.rasmussen@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yuyang Du <yuyang.du@intel.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-12sched/nohz: Fix affine unpinned timers messWanpeng Li1-1/+4
The following commit: 9642d18eee2c ("nohz: Affine unpinned timers to housekeepers")' intended to affine unpinned timers to housekeepers: unpinned timers(full dynaticks, idle) => nearest busy housekeepers(otherwise, fallback to any housekeepers) unpinned timers(full dynaticks, busy) => nearest busy housekeepers(otherwise, fallback to any housekeepers) unpinned timers(houserkeepers, idle) => nearest busy housekeepers(otherwise, fallback to itself) However, the !idle_cpu(i) && is_housekeeping_cpu(cpu) check modified the intention to: unpinned timers(full dynaticks, idle) => any housekeepers(no mattter cpu topology) unpinned timers(full dynaticks, busy) => any housekeepers(no mattter cpu topology) unpinned timers(housekeepers, idle) => any busy cpus(otherwise, fallback to any housekeepers) This patch fixes it by checking if there are busy housekeepers nearby, otherwise falls to any housekeepers/itself. After the patch: unpinned timers(full dynaticks, idle) => nearest busy housekeepers(otherwise, fallback to any housekeepers) unpinned timers(full dynaticks, busy) => nearest busy housekeepers(otherwise, fallback to any housekeepers) unpinned timers(housekeepers, idle) => nearest busy housekeepers(otherwise, fallback to itself) Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> [ Fixed the changelog. ] Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Fixes: 'commit 9642d18eee2c ("nohz: Affine unpinned timers to housekeepers")' Link: http://lkml.kernel.org/r/1462344334-8303-1-git-send-email-wanpeng.li@hotmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-12sched/fair: Fix fairness issue on migrationPeter Zijlstra1-6/+16
Pavan reported that in the presence of very light tasks (or cgroups) the placement of migrated tasks can cause severe fairness issues. The problem is that enqueue_entity() places the task before it updates time, thereby it can place the task far in the past (remember that light tasks will shoot virtual time forward at a high speed, so in relation to the pre-existing light task, we can land far in the past). This is done because update_curr() needs the current task, and we might be placing the current task. The obvious solution is to differentiate between the current and any other task; placing the current before we update time, and placing any other task after, such that !curr tasks end up at the current moment in time, and not in the past. This commit re-introduces the previously reverted commit: 3a47d5124a95 ("sched/fair: Fix fairness issue on migration") ... which is now safe to do, after we've also fixed another underlying bug first, in: sched/fair: Prepare to fix fairness problems on migration and cleaned up other details in the migration code: sched/core: Kill sched_class::task_waking Reported-by: Pavan Kondeti <pkondeti@codeaurora.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-12sched/core: Kill sched_class::task_waking to clean up the migration logicPeter Zijlstra3-42/+32
With sched_class::task_waking being called only when we do set_task_cpu(), we can make sched_class::migrate_task_rq() do the work and eliminate sched_class::task_waking entirely. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Hunter <ahh@google.com> Cc: Ben Segall <bsegall@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Mike Galbraith <efault@gmx.de> Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Morten Rasmussen <morten.rasmussen@arm.com> Cc: Paul Turner <pjt@google.com> Cc: Pavan Kondeti <pkondeti@codeaurora.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: byungchul.park@lge.com Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>