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2019-09-17Merge branch 'timers-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core timer updates from Thomas Gleixner: "Timers and timekeeping updates: - A large overhaul of the posix CPU timer code which is a preparation for moving the CPU timer expiry out into task work so it can be properly accounted on the task/process. An update to the bogus permission checks will come later during the merge window as feedback was not complete before heading of for travel. - Switch the timerqueue code to use cached rbtrees and get rid of the homebrewn caching of the leftmost node. - Consolidate hrtimer_init() + hrtimer_init_sleeper() calls into a single function - Implement the separation of hrtimers to be forced to expire in hard interrupt context even when PREEMPT_RT is enabled and mark the affected timers accordingly. - Implement a mechanism for hrtimers and the timer wheel to protect RT against priority inversion and live lock issues when a (hr)timer which should be canceled is currently executing the callback. Instead of infinitely spinning, the task which tries to cancel the timer blocks on a per cpu base expiry lock which is held and released by the (hr)timer expiry code. - Enable the Hyper-V TSC page based sched_clock for Hyper-V guests resulting in faster access to timekeeping functions. - Updates to various clocksource/clockevent drivers and their device tree bindings. - The usual small improvements all over the place" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (101 commits) posix-cpu-timers: Fix permission check regression posix-cpu-timers: Always clear head pointer on dequeue hrtimer: Add a missing bracket and hide `migration_base' on !SMP posix-cpu-timers: Make expiry_active check actually work correctly posix-timers: Unbreak CONFIG_POSIX_TIMERS=n build tick: Mark sched_timer to expire in hard interrupt context hrtimer: Add kernel doc annotation for HRTIMER_MODE_HARD x86/hyperv: Hide pv_ops access for CONFIG_PARAVIRT=n posix-cpu-timers: Utilize timerqueue for storage posix-cpu-timers: Move state tracking to struct posix_cputimers posix-cpu-timers: Deduplicate rlimit handling posix-cpu-timers: Remove pointless comparisons posix-cpu-timers: Get rid of 64bit divisions posix-cpu-timers: Consolidate timer expiry further posix-cpu-timers: Get rid of zero checks rlimit: Rewrite non-sensical RLIMIT_CPU comment posix-cpu-timers: Respect INFINITY for hard RTTIME limit posix-cpu-timers: Switch thread group sampling to array posix-cpu-timers: Restructure expiry array posix-cpu-timers: Remove cputime_expires ...
2019-09-16Merge branch 'sched-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: - MAINTAINERS: Add Mark Rutland as perf submaintainer, Juri Lelli and Vincent Guittot as scheduler submaintainers. Add Dietmar Eggemann, Steven Rostedt, Ben Segall and Mel Gorman as scheduler reviewers. As perf and the scheduler is getting bigger and more complex, document the status quo of current responsibilities and interests, and spread the review pain^H^H^H^H fun via an increase in the Cc: linecount generated by scripts/get_maintainer.pl. :-) - Add another series of patches that brings the -rt (PREEMPT_RT) tree closer to mainline: split the monolithic CONFIG_PREEMPT dependencies into a new CONFIG_PREEMPTION category that will allow the eventual introduction of CONFIG_PREEMPT_RT. Still a few more hundred patches to go though. - Extend the CPU cgroup controller with uclamp.min and uclamp.max to allow the finer shaping of CPU bandwidth usage. - Micro-optimize energy-aware wake-ups from O(CPUS^2) to O(CPUS). - Improve the behavior of high CPU count, high thread count applications running under cpu.cfs_quota_us constraints. - Improve balancing with SCHED_IDLE (SCHED_BATCH) tasks present. - Improve CPU isolation housekeeping CPU allocation NUMA locality. - Fix deadline scheduler bandwidth calculations and logic when cpusets rebuilds the topology, or when it gets deadline-throttled while it's being offlined. - Convert the cpuset_mutex to percpu_rwsem, to allow it to be used from setscheduler() system calls without creating global serialization. Add new synchronization between cpuset topology-changing events and the deadline acceptance tests in setscheduler(), which were broken before. - Rework the active_mm state machine to be less confusing and more optimal. - Rework (simplify) the pick_next_task() slowpath. - Improve load-balancing on AMD EPYC systems. - ... and misc cleanups, smaller fixes and improvements - please see the Git log for more details. * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits) sched/psi: Correct overly pessimistic size calculation sched/fair: Speed-up energy-aware wake-ups sched/uclamp: Always use 'enum uclamp_id' for clamp_id values sched/uclamp: Update CPU's refcount on TG's clamp changes sched/uclamp: Use TG's clamps to restrict TASK's clamps sched/uclamp: Propagate system defaults to the root group sched/uclamp: Propagate parent clamps sched/uclamp: Extend CPU's cgroup controller sched/topology: Improve load balancing on AMD EPYC systems arch, ia64: Make NUMA select SMP sched, perf: MAINTAINERS update, add submaintainers and reviewers sched/fair: Use rq_lock/unlock in online_fair_sched_group cpufreq: schedutil: fix equation in comment sched: Rework pick_next_task() slow-path sched: Allow put_prev_task() to drop rq->lock sched/fair: Expose newidle_balance() sched: Add task_struct pointer to sched_class::set_curr_task sched: Rework CPU hotplug task selection sched/{rt,deadline}: Fix set_next_task vs pick_next_task sched: Fix kerneldoc comment for ia64_set_curr_task ...
2019-09-16Merge branch 'sched/rt' into sched/core, to pick up -rt changesIngo Molnar
Pick up the first couple of patches working towards PREEMPT_RT. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-03sched/uclamp: Extend CPU's cgroup controllerPatrick Bellasi
The cgroup CPU bandwidth controller allows to assign a specified (maximum) bandwidth to the tasks of a group. However this bandwidth is defined and enforced only on a temporal base, without considering the actual frequency a CPU is running on. Thus, the amount of computation completed by a task within an allocated bandwidth can be very different depending on the actual frequency the CPU is running that task. The amount of computation can be affected also by the specific CPU a task is running on, especially when running on asymmetric capacity systems like Arm's big.LITTLE. With the availability of schedutil, the scheduler is now able to drive frequency selections based on actual task utilization. Moreover, the utilization clamping support provides a mechanism to bias the frequency selection operated by schedutil depending on constraints assigned to the tasks currently RUNNABLE on a CPU. Giving the mechanisms described above, it is now possible to extend the cpu controller to specify the minimum (or maximum) utilization which should be considered for tasks RUNNABLE on a cpu. This makes it possible to better defined the actual computational power assigned to task groups, thus improving the cgroup CPU bandwidth controller which is currently based just on time constraints. Extend the CPU controller with a couple of new attributes uclamp.{min,max} which allow to enforce utilization boosting and capping for all the tasks in a group. Specifically: - uclamp.min: defines the minimum utilization which should be considered i.e. the RUNNABLE tasks of this group will run at least at a minimum frequency which corresponds to the uclamp.min utilization - uclamp.max: defines the maximum utilization which should be considered i.e. the RUNNABLE tasks of this group will run up to a maximum frequency which corresponds to the uclamp.max utilization These attributes: a) are available only for non-root nodes, both on default and legacy hierarchies, while system wide clamps are defined by a generic interface which does not depends on cgroups. This system wide interface enforces constraints on tasks in the root node. b) enforce effective constraints at each level of the hierarchy which are a restriction of the group requests considering its parent's effective constraints. Root group effective constraints are defined by the system wide interface. This mechanism allows each (non-root) level of the hierarchy to: - request whatever clamp values it would like to get - effectively get only up to the maximum amount allowed by its parent c) have higher priority than task-specific clamps, defined via sched_setattr(), thus allowing to control and restrict task requests. Add two new attributes to the cpu controller to collect "requested" clamp values. Allow that at each non-root level of the hierarchy. Keep it simple by not caring now about "effective" values computation and propagation along the hierarchy. Update sysctl_sched_uclamp_handler() to use the newly introduced uclamp_mutex so that we serialize system default updates with cgroup relate updates. Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Michal Koutny <mkoutny@suse.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Alessio Balsini <balsini@android.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten Rasmussen <morten.rasmussen@arm.com> Cc: Paul Turner <pjt@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Perret <quentin.perret@arm.com> Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com> Cc: Steve Muckle <smuckle@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Todd Kjos <tkjos@google.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Link: https://lkml.kernel.org/r/20190822132811.31294-2-patrick.bellasi@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-08-28posix-cpu-timers: Move state tracking to struct posix_cputimersThomas Gleixner
Put it where it belongs and clean up the ifdeffery in fork completely. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190821192922.743229404@linutronix.de
2019-08-20Revert "init/Kconfig: Fix infinite Kconfig recursion on PPC"Will Deacon
This reverts commit 71c67a31f09fa8fdd1495dffd96a5f0d4cef2ede. Commit 117acf5c29dd ("powerpc/Makefile: Always pass --synthetic to nm if supported") removed the only conditional definition of $(NM), so we can revert our temporary bodge to avoid Kconfig recursion and go back to passing $(NM) through to the 'tools-support-relr.sh' when detecting support for RELR relocations. Signed-off-by: Will Deacon <will@kernel.org>
2019-08-07init/Kconfig: Fix infinite Kconfig recursion on PPCWill Deacon
Commit 5cf896fb6be3 ("arm64: Add support for relocating the kernel with RELR relocations") introduced CONFIG_TOOLS_SUPPORT_RELR, which checks for RELR support in the toolchain as part of the kernel configuration. During this procedure, "$(NM)" is invoked to see if it supports the new relocation format, however PowerPC conditionally overrides this variable in the architecture Makefile in order to pass '--synthetic' when targetting PPC64. This conditional override causes Kconfig to recurse forever, since CONFIG_TOOLS_SUPPORT_RELR cannot be determined without $(NM) being defined, but that in turn depends on CONFIG_PPC64: $ make ARCH=powerpc CROSS_COMPILE=powerpc-linux-gnu- scripts/kconfig/conf --syncconfig Kconfig scripts/kconfig/conf --syncconfig Kconfig scripts/kconfig/conf --syncconfig Kconfig [...] In this particular case, it looks like PowerPC may be able to pass '--synthetic' unconditionally to nm or even drop it altogether. While that is being resolved, let's just bodge the RELR check by picking up $(NM) directly from the environment in whatever state it happens to be in. Cc: Peter Collingbourne <pcc@google.com> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-05arm64: Add support for relocating the kernel with RELR relocationsPeter Collingbourne
RELR is a relocation packing format for relative relocations. The format is described in a generic-abi proposal: https://groups.google.com/d/topic/generic-abi/bX460iggiKg/discussion The LLD linker can be instructed to pack relocations in the RELR format by passing the flag --pack-dyn-relocs=relr. This patch adds a new config option, CONFIG_RELR. Enabling this option instructs the linker to pack vmlinux's relative relocations in the RELR format, and causes the kernel to apply the relocations at startup along with the RELA relocations. RELA relocations still need to be applied because the linker will emit RELA relative relocations if they are unrepresentable in the RELR format (i.e. address not a multiple of 2). Enabling CONFIG_RELR reduces the size of a defconfig kernel image with CONFIG_RANDOMIZE_BASE by 3.5MB/16% uncompressed, or 550KB/5% compressed (lz4). Signed-off-by: Peter Collingbourne <pcc@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-07-31sched/preempt: Use CONFIG_PREEMPTION where appropriateThomas Gleixner
CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by CONFIG_PREEMPT_RT. Both PREEMPT and PREEMPT_RT require the same functionality which today depends on CONFIG_PREEMPT. Switch the preemption code, scheduler and init task over to use CONFIG_PREEMPTION. That's the first step towards RT in that area. The more complex changes are coming separately. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Paul E. McKenney <paulmck@linux.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20190726212124.117528401@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-19Merge branch 'work.mount0' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs mount updates from Al Viro: "The first part of mount updates. Convert filesystems to use the new mount API" * 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits) mnt_init(): call shmem_init() unconditionally constify ksys_mount() string arguments don't bother with registering rootfs init_rootfs(): don't bother with init_ramfs_fs() vfs: Convert smackfs to use the new mount API vfs: Convert selinuxfs to use the new mount API vfs: Convert securityfs to use the new mount API vfs: Convert apparmorfs to use the new mount API vfs: Convert openpromfs to use the new mount API vfs: Convert xenfs to use the new mount API vfs: Convert gadgetfs to use the new mount API vfs: Convert oprofilefs to use the new mount API vfs: Convert ibmasmfs to use the new mount API vfs: Convert qib_fs/ipathfs to use the new mount API vfs: Convert efivarfs to use the new mount API vfs: Convert configfs to use the new mount API vfs: Convert binfmt_misc to use the new mount API convenience helper: get_tree_single() convenience helper get_tree_nodev() vfs: Kill sget_userns() ...
2019-07-17Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge more updates from Andrew Morton: "VM: - z3fold fixes and enhancements by Henry Burns and Vitaly Wool - more accurate reclaimed slab caches calculations by Yafang Shao - fix MAP_UNINITIALIZED UAPI symbol to not depend on config, by Christoph Hellwig - !CONFIG_MMU fixes by Christoph Hellwig - new novmcoredd parameter to omit device dumps from vmcore, by Kairui Song - new test_meminit module for testing heap and pagealloc initialization, by Alexander Potapenko - ioremap improvements for huge mappings, by Anshuman Khandual - generalize kprobe page fault handling, by Anshuman Khandual - device-dax hotplug fixes and improvements, by Pavel Tatashin - enable synchronous DAX fault on powerpc, by Aneesh Kumar K.V - add pte_devmap() support for arm64, by Robin Murphy - unify locked_vm accounting with a helper, by Daniel Jordan - several misc fixes core/lib: - new typeof_member() macro including some users, by Alexey Dobriyan - make BIT() and GENMASK() available in asm, by Masahiro Yamada - changed LIST_POISON2 on x86_64 to 0xdead000000000122 for better code generation, by Alexey Dobriyan - rbtree code size optimizations, by Michel Lespinasse - convert struct pid count to refcount_t, by Joel Fernandes get_maintainer.pl: - add --no-moderated switch to skip moderated ML's, by Joe Perches misc: - ptrace PTRACE_GET_SYSCALL_INFO interface - coda updates - gdb scripts, various" [ Using merge message suggestion from Vlastimil Babka, with some editing - Linus ] * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (100 commits) fs/select.c: use struct_size() in kmalloc() mm: add account_locked_vm utility function arm64: mm: implement pte_devmap support mm: introduce ARCH_HAS_PTE_DEVMAP mm: clean up is_device_*_page() definitions mm/mmap: move common defines to mman-common.h mm: move MAP_SYNC to asm-generic/mman-common.h device-dax: "Hotremove" persistent memory that is used like normal RAM mm/hotplug: make remove_memory() interface usable device-dax: fix memory and resource leak if hotplug fails include/linux/lz4.h: fix spelling and copy-paste errors in documentation ipc/mqueue.c: only perform resource calculation if user valid include/asm-generic/bug.h: fix "cut here" for WARN_ON for __WARN_TAINT architectures scripts/gdb: add helpers to find and list devices scripts/gdb: add lx-genpd-summary command drivers/pps/pps.c: clear offset flags in PPS_SETPARAMS ioctl kernel/pid.c: convert struct pid count to refcount_t drivers/rapidio/devices/rio_mport_cdev.c: NUL terminate some strings select: shift restore_saved_sigmask_unless() into poll_select_copy_remaining() select: change do_poll() to return -ERESTARTNOHAND rather than -EINTR ...
2019-07-16init/Kconfig: fix neighboring typosKees Cook
This fixes a couple typos I noticed in the slab Kconfig: sacrifies -> sacrifices accellerate -> accelerate Seeing as no other instances of these typos are found elsewhere in the kernel and that I originally added one of the two, I can only assume working on slab must have caused damage to the spelling centers of my brain. Link: http://lkml.kernel.org/r/201905292203.CD000546EB@keescook Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-15docs: cgroup-v1: add it to the admin-guide bookMauro Carvalho Chehab
Those files belong to the admin guide, so add them. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-07-15docs: accounting: convert to ReSTMauro Carvalho Chehab
Rename the accounting documentation files to ReST, add an index for them and adjust in order to produce a nice html output via the Sphinx build system. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-07-12Merge tag 'kbuild-v5.3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - remove headers_{install,check}_all targets - remove unreasonable 'depends on !UML' from CONFIG_SAMPLES - re-implement 'make headers_install' more cleanly - add new header-test-y syntax to compile-test headers - compile-test exported headers to ensure they are compilable in user-space - compile-test headers under include/ to ensure they are self-contained - remove -Waggregate-return, -Wno-uninitialized, -Wno-unused-value flags - add -Werror=unknown-warning-option for Clang - add 128-bit built-in types support to genksyms - fix missed rebuild of modules.builtin - propagate 'No space left on device' error in fixdep to Make - allow Clang to use its integrated assembler - improve some coccinelle scripts - add a new flag KBUILD_ABS_SRCTREE to request Kbuild to use absolute path for $(srctree). - do not ignore errors when compression utility is missing - misc cleanups * tag 'kbuild-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (49 commits) kbuild: use -- separater intead of $(filter-out ...) for cc-cross-prefix kbuild: Inform user to pass ARCH= for make mrproper kbuild: fix compression errors getting ignored kbuild: add a flag to force absolute path for srctree kbuild: replace KBUILD_SRCTREE with boolean building_out_of_srctree kbuild: remove src and obj from the top Makefile scripts/tags.sh: remove unused environment variables from comments scripts/tags.sh: drop SUBARCH support for ARM kbuild: compile-test kernel headers to ensure they are self-contained kheaders: include only headers into kheaders_data.tar.xz kheaders: remove meaningless -R option of 'ls' kbuild: support header-test-pattern-y kbuild: do not create wrappers for header-test-y kbuild: compile-test exported headers to ensure they are self-contained init/Kconfig: add CONFIG_CC_CAN_LINK kallsyms: exclude kasan local symbols on s390 kbuild: add more hints about SUBDIRS replacement coccinelle: api/stream_open: treat all wait_.*() calls as blocking coccinelle: put_device: Add a cast to an expression for an assignment coccinelle: put_device: Adjust a message construction ...
2019-07-12mm: init: report memory auto-initialization features at boot timeAlexander Potapenko
Print the currently enabled stack and heap initialization modes. Stack initialization is enabled by a config flag, while heap initialization is configured at boot time with defaults being set in the config. It's more convenient for the user to have all information about these hardening measures in one place at boot, so the user can reason about the expected behavior of the running system. The possible options for stack are: - "all" for CONFIG_INIT_STACK_ALL; - "byref_all" for CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL; - "byref" for CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF; - "__user" for CONFIG_GCC_PLUGIN_STRUCTLEAK_USER; - "off" otherwise. Depending on the values of init_on_alloc and init_on_free boottime options we also report "heap alloc" and "heap free" as "on"/"off". In the init_on_free mode initializing pages at boot time may take a while, so print a notice about that as well. This depends on how much memory is installed, the memory bandwidth, etc. On a relatively modern x86 system, it takes about 0.75s/GB to wipe all memory: [ 0.418722] mem auto-init: stack:byref_all, heap alloc:off, heap free:on [ 0.419765] mem auto-init: clearing system memory may take some time... [ 12.376605] Memory: 16408564K/16776672K available (14339K kernel code, 1397K rwdata, 3756K rodata, 1636K init, 11460K bss, 368108K reserved, 0K cma-reserved) Link: http://lkml.kernel.org/r/20190617151050.92663-3-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Suggested-by: Kees Cook <keescook@chromium.org> Acked-by: Kees Cook <keescook@chromium.org> Cc: Christoph Lameter <cl@linux.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: James Morris <jmorris@namei.org> Cc: Jann Horn <jannh@google.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Laura Abbott <labbott@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Sandeep Patil <sspatil@android.com> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Souptick Joarder <jrdr.linux@gmail.com> Cc: Marco Elver <elver@google.com> Cc: Kaiwan N Billimoria <kaiwan@kaiwantech.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-09Merge tag 'docs-5.3' of git://git.lwn.net/linuxLinus Torvalds
Pull Documentation updates from Jonathan Corbet: "It's been a relatively busy cycle for docs: - A fair pile of RST conversions, many from Mauro. These create more than the usual number of simple but annoying merge conflicts with other trees, unfortunately. He has a lot more of these waiting on the wings that, I think, will go to you directly later on. - A new document on how to use merges and rebases in kernel repos, and one on Spectre vulnerabilities. - Various improvements to the build system, including automatic markup of function() references because some people, for reasons I will never understand, were of the opinion that :c:func:``function()`` is unattractive and not fun to type. - We now recommend using sphinx 1.7, but still support back to 1.4. - Lots of smaller improvements, warning fixes, typo fixes, etc" * tag 'docs-5.3' of git://git.lwn.net/linux: (129 commits) docs: automarkup.py: ignore exceptions when seeking for xrefs docs: Move binderfs to admin-guide Disable Sphinx SmartyPants in HTML output doc: RCU callback locks need only _bh, not necessarily _irq docs: format kernel-parameters -- as code Doc : doc-guide : Fix a typo platform: x86: get rid of a non-existent document Add the RCU docs to the core-api manual Documentation: RCU: Add TOC tree hooks Documentation: RCU: Rename txt files to rst Documentation: RCU: Convert RCU UP systems to reST Documentation: RCU: Convert RCU linked list to reST Documentation: RCU: Convert RCU basic concepts to reST docs: filesystems: Remove uneeded .rst extension on toctables scripts/sphinx-pre-install: fix out-of-tree build docs: zh_CN: submitting-drivers.rst: Remove a duplicated Documentation/ Documentation: PGP: update for newer HW devices Documentation: Add section about CPU vulnerabilities for Spectre Documentation: platform: Delete x86-laptop-drivers.txt docs: Note that :c:func: should no longer be used ...
2019-07-09Merge tag 'for-5.3/block-20190708' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block updates from Jens Axboe: "This is the main block updates for 5.3. Nothing earth shattering or major in here, just fixes, additions, and improvements all over the map. This contains: - Series of documentation fixes (Bart) - Optimization of the blk-mq ctx get/put (Bart) - null_blk removal race condition fix (Bob) - req/bio_op() cleanups (Chaitanya) - Series cleaning up the segment accounting, and request/bio mapping (Christoph) - Series cleaning up the page getting/putting for bios (Christoph) - block cgroup cleanups and moving it to where it is used (Christoph) - block cgroup fixes (Tejun) - Series of fixes and improvements to bcache, most notably a write deadlock fix (Coly) - blk-iolatency STS_AGAIN and accounting fixes (Dennis) - Series of improvements and fixes to BFQ (Douglas, Paolo) - debugfs_create() return value check removal for drbd (Greg) - Use struct_size(), where appropriate (Gustavo) - Two lighnvm fixes (Heiner, Geert) - MD fixes, including a read balance and corruption fix (Guoqing, Marcos, Xiao, Yufen) - block opal shadow mbr additions (Jonas, Revanth) - sbitmap compare-and-exhange improvemnts (Pavel) - Fix for potential bio->bi_size overflow (Ming) - NVMe pull requests: - improved PCIe suspent support (Keith Busch) - error injection support for the admin queue (Akinobu Mita) - Fibre Channel discovery improvements (James Smart) - tracing improvements including nvmetc tracing support (Minwoo Im) - misc fixes and cleanups (Anton Eidelman, Minwoo Im, Chaitanya Kulkarni)" - Various little fixes and improvements to drivers and core" * tag 'for-5.3/block-20190708' of git://git.kernel.dk/linux-block: (153 commits) blk-iolatency: fix STS_AGAIN handling block: nr_phys_segments needs to be zero for REQ_OP_WRITE_ZEROES blk-mq: simplify blk_mq_make_request() blk-mq: remove blk_mq_put_ctx() sbitmap: Replace cmpxchg with xchg block: fix .bi_size overflow block: sed-opal: check size of shadow mbr block: sed-opal: ioctl for writing to shadow mbr block: sed-opal: add ioctl for done-mark of shadow mbr block: never take page references for ITER_BVEC direct-io: use bio_release_pages in dio_bio_complete block_dev: use bio_release_pages in bio_unmap_user block_dev: use bio_release_pages in blkdev_bio_end_io iomap: use bio_release_pages in iomap_dio_bio_end_io block: use bio_release_pages in bio_map_user_iov block: use bio_release_pages in bio_unmap_user block: optionally mark pages dirty in bio_release_pages block: move the BIO_NO_PAGE_REF check into bio_release_pages block: skd_main.c: Remove call to memset after dma_alloc_coherent block: mtip32xx: Remove call to memset after dma_alloc_coherent ...
2019-07-09kbuild: compile-test kernel headers to ensure they are self-containedMasahiro Yamada
The headers in include/ are globally used in the kernel source tree to provide common APIs. They are included from external modules, too. It will be useful to make as many headers self-contained as possible so that we do not have to rely on a specific include order. There are more than 4000 headers in include/. In my rough analysis, 70% of them are already self-contained. With efforts, most of them can be self-contained. For now, we must exclude more than 1000 headers just because they cannot be compiled as standalone units. I added them to header-test-. The blacklist was mostly generated by a script, so the reason of the breakage should be checked later. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Tested-by: Jani Nikula <jani.nikula@intel.com> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
2019-07-08Merge branch 'for-5.3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "Documentation updates and the addition of cgroup_parse_float() which will be used by new controllers including blk-iocost" * 'for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: docs: cgroup-v1: convert docs to ReST and rename to *.rst cgroup: Move cgroup_parse_float() implementation out of CONFIG_SYSFS cgroup: add cgroup_parse_float()
2019-07-08Merge branch 'sched-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: - Remove the unused per rq load array and all its infrastructure, by Dietmar Eggemann. - Add utilization clamping support by Patrick Bellasi. This is a refinement of the energy aware scheduling framework with support for boosting of interactive and capping of background workloads: to make sure critical GUI threads get maximum frequency ASAP, and to make sure background processing doesn't unnecessarily move to cpufreq governor to higher frequencies and less energy efficient CPU modes. - Add the bare minimum of tracepoints required for LISA EAS regression testing, by Qais Yousef - which allows automated testing of various power management features, including energy aware scheduling. - Restructure the former tsk_nr_cpus_allowed() facility that the -rt kernel used to modify the scheduler's CPU affinity logic such as migrate_disable() - introduce the task->cpus_ptr value instead of taking the address of &task->cpus_allowed directly - by Sebastian Andrzej Siewior. - Misc optimizations, fixes, cleanups and small enhancements - see the Git log for details. * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits) sched/uclamp: Add uclamp support to energy_compute() sched/uclamp: Add uclamp_util_with() sched/cpufreq, sched/uclamp: Add clamps for FAIR and RT tasks sched/uclamp: Set default clamps for RT tasks sched/uclamp: Reset uclamp values on RESET_ON_FORK sched/uclamp: Extend sched_setattr() to support utilization clamping sched/core: Allow sched_setattr() to use the current policy sched/uclamp: Add system default clamps sched/uclamp: Enforce last task's UCLAMP_MAX sched/uclamp: Add bucket local max tracking sched/uclamp: Add CPU's clamp buckets refcounting sched/fair: Rename weighted_cpuload() to cpu_runnable_load() sched/debug: Export the newly added tracepoints sched/debug: Add sched_overutilized tracepoint sched/debug: Add new tracepoint to track PELT at se level sched/debug: Add new tracepoints to track PELT at rq level sched/debug: Add a new sched_trace_*() helper functions sched/autogroup: Make autogroup_path() always available sched/wait: Deduplicate code with do-while sched/topology: Remove unused 'sd' parameter from arch_scale_cpu_capacity() ...
2019-07-08Merge branch 'locking-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Ingo Molnar: "The main changes in this cycle are: - rwsem scalability improvements, phase #2, by Waiman Long, which are rather impressive: "On a 2-socket 40-core 80-thread Skylake system with 40 reader and writer locking threads, the min/mean/max locking operations done in a 5-second testing window before the patchset were: 40 readers, Iterations Min/Mean/Max = 1,807/1,808/1,810 40 writers, Iterations Min/Mean/Max = 1,807/50,344/151,255 After the patchset, they became: 40 readers, Iterations Min/Mean/Max = 30,057/31,359/32,741 40 writers, Iterations Min/Mean/Max = 94,466/95,845/97,098" There's a lot of changes to the locking implementation that makes it similar to qrwlock, including owner handoff for more fair locking. Another microbenchmark shows how across the spectrum the improvements are: "With a locking microbenchmark running on 5.1 based kernel, the total locking rates (in kops/s) on a 2-socket Skylake system with equal numbers of readers and writers (mixed) before and after this patchset were: # of Threads Before Patch After Patch ------------ ------------ ----------- 2 2,618 4,193 4 1,202 3,726 8 802 3,622 16 729 3,359 32 319 2,826 64 102 2,744" The changes are extensive and the patch-set has been through several iterations addressing various locking workloads. There might be more regressions, but unless they are pathological I believe we want to use this new implementation as the baseline going forward. - jump-label optimizations by Daniel Bristot de Oliveira: the primary motivation was to remove IPI disturbance of isolated RT-workload CPUs, which resulted in the implementation of batched jump-label updates. Beyond the improvement of the real-time characteristics kernel, in one test this patchset improved static key update overhead from 57 msecs to just 1.4 msecs - which is a nice speedup as well. - atomic64_t cross-arch type cleanups by Mark Rutland: over the last ~10 years of atomic64_t existence the various types used by the APIs only had to be self-consistent within each architecture - which means they became wildly inconsistent across architectures. Mark puts and end to this by reworking all the atomic64 implementations to use 's64' as the base type for atomic64_t, and to ensure that this type is consistently used for parameters and return values in the API, avoiding further problems in this area. - A large set of small improvements to lockdep by Yuyang Du: type cleanups, output cleanups, function return type and othr cleanups all around the place. - A set of percpu ops cleanups and fixes by Peter Zijlstra. - Misc other changes - please see the Git log for more details" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (82 commits) locking/lockdep: increase size of counters for lockdep statistics locking/atomics: Use sed(1) instead of non-standard head(1) option locking/lockdep: Move mark_lock() inside CONFIG_TRACE_IRQFLAGS && CONFIG_PROVE_LOCKING x86/jump_label: Make tp_vec_nr static x86/percpu: Optimize raw_cpu_xchg() x86/percpu, sched/fair: Avoid local_clock() x86/percpu, x86/irq: Relax {set,get}_irq_regs() x86/percpu: Relax smp_processor_id() x86/percpu: Differentiate this_cpu_{}() and __this_cpu_{}() locking/rwsem: Guard against making count negative locking/rwsem: Adaptive disabling of reader optimistic spinning locking/rwsem: Enable time-based spinning on reader-owned rwsem locking/rwsem: Make rwsem->owner an atomic_long_t locking/rwsem: Enable readers spinning on writer locking/rwsem: Clarify usage of owner's nonspinaable bit locking/rwsem: Wake up almost all readers in wait queue locking/rwsem: More optimal RT task handling of null owner locking/rwsem: Always release wait_lock before waking up tasks locking/rwsem: Implement lock handoff to prevent lock starvation locking/rwsem: Make rwsem_spin_on_owner() return owner state ...
2019-07-08kbuild: compile-test exported headers to ensure they are self-containedMasahiro Yamada
Multiple people have suggested compile-testing UAPI headers to ensure they can be really included from user-space. "make headers_check" is obviously not enough to catch bugs, and we often leak unresolved references to user-space. Use the new header-test-y syntax to implement it. Please note exported headers are compile-tested with a completely different set of compiler flags. The header search path is set to $(objtree)/usr/include since exported headers should not include unexported ones. We use -std=gnu89 for the kernel space since the kernel code highly depends on GNU extensions. On the other hand, UAPI headers should be written in more standardized C, so they are compiled with -std=c90. This will emit errors if C++ style comments, the keyword 'inline', etc. are used. Please use C style comments (/* ... */), '__inline__', etc. in UAPI headers. There is additional compiler requirement to enable this test because many of UAPI headers include <stdlib.h>, <sys/ioctl.h>, <sys/time.h>, etc. directly or indirectly. You cannot use kernel.org pre-built toolchains [1] since they lack <stdlib.h>. I reused CONFIG_CC_CAN_LINK to check the system header availability. The intention is slightly different, but a compiler that can link userspace programs provide system headers. For now, a lot of headers need to be excluded because they cannot be compiled standalone, but this is a good start point. [1] https://mirrors.edge.kernel.org/pub/tools/crosstool/index.html Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
2019-07-08init/Kconfig: add CONFIG_CC_CAN_LINKMasahiro Yamada
Currently, scripts/cc-can-link.sh is run just for BPFILTER_UMH, but defining CC_CAN_LINK will be useful in other places. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-04mnt_init(): call shmem_init() unconditionallyAl Viro
No point having two call sites (earlier in init_rootfs() from mnt_init() in case we are going to use shmem-style rootfs, later from do_basic_setup() unconditionally), along with the logics in shmem_init() itself to make the second call a no-op... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-07-04don't bother with registering rootfsAl Viro
init_mount_tree() can get to rootfs_fs_type directly and that simplifies a lot of things. We don't need to register it, we don't need to look it up *and* we don't need to bother with preventing subsequent userland mounts. That's the way we should've done that from the very beginning. There is a user-visible change, namely the disappearance of "rootfs" from /proc/filesystems. Note that it's been unmountable all along and it didn't show up in /proc/mounts; however, it *is* a user-visible change and theoretically some script might've been using its presence in /proc/filesystems to tell 2.4.11+ from earlier kernels. *IF* any complaints about behaviour change do show up, we could fake it in /proc/filesystems. I very much doubt we'll have to, though. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-07-04init_rootfs(): don't bother with init_ramfs_fs()Al Viro
the only thing done by the latter is making ramfs visible to mount(2); we don't need it there - rootfs is separate and, in fact, made visible to mount(2) in the same init_rootfs(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-06-29initramfs: fix populate_initrd_image() section mismatchGeert Uytterhoeven
With gcc-4.6.3: WARNING: vmlinux.o(.text.unlikely+0x140): Section mismatch in reference from the function populate_initrd_image() to the variable .init.ramfs.info:__initramfs_size The function populate_initrd_image() references the variable __init __initramfs_size. This is often because populate_initrd_image lacks a __init annotation or the annotation of __initramfs_size is wrong. WARNING: vmlinux.o(.text.unlikely+0x14c): Section mismatch in reference from the function populate_initrd_image() to the function .init.text:unpack_to_rootfs() The function populate_initrd_image() references the function __init unpack_to_rootfs(). This is often because populate_initrd_image lacks a __init annotation or the annotation of unpack_to_rootfs is wrong. WARNING: vmlinux.o(.text.unlikely+0x198): Section mismatch in reference from the function populate_initrd_image() to the function .init.text:xwrite() The function populate_initrd_image() references the function __init xwrite(). This is often because populate_initrd_image lacks a __init annotation or the annotation of xwrite is wrong. Indeed, if the compiler decides not to inline populate_initrd_image(), a warning is generated. Fix this by adding the missing __init annotations. Link: http://lkml.kernel.org/r/20190617074340.12779-1-geert@linux-m68k.org Fixes: 7c184ecd262fe64f ("initramfs: factor out a helper to populate the initrd image") Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-06-24sched/uclamp: Add CPU's clamp buckets refcountingPatrick Bellasi
Utilization clamping allows to clamp the CPU's utilization within a [util_min, util_max] range, depending on the set of RUNNABLE tasks on that CPU. Each task references two "clamp buckets" defining its minimum and maximum (util_{min,max}) utilization "clamp values". A CPU's clamp bucket is active if there is at least one RUNNABLE tasks enqueued on that CPU and refcounting that bucket. When a task is {en,de}queued {on,from} a rq, the set of active clamp buckets on that CPU can change. If the set of active clamp buckets changes for a CPU a new "aggregated" clamp value is computed for that CPU. This is because each clamp bucket enforces a different utilization clamp value. Clamp values are always MAX aggregated for both util_min and util_max. This ensures that no task can affect the performance of other co-scheduled tasks which are more boosted (i.e. with higher util_min clamp) or less capped (i.e. with higher util_max clamp). A task has: task_struct::uclamp[clamp_id]::bucket_id to track the "bucket index" of the CPU's clamp bucket it refcounts while enqueued, for each clamp index (clamp_id). A runqueue has: rq::uclamp[clamp_id]::bucket[bucket_id].tasks to track how many RUNNABLE tasks on that CPU refcount each clamp bucket (bucket_id) of a clamp index (clamp_id). It also has a: rq::uclamp[clamp_id]::bucket[bucket_id].value to track the clamp value of each clamp bucket (bucket_id) of a clamp index (clamp_id). The rq::uclamp::bucket[clamp_id][] array is scanned every time it's needed to find a new MAX aggregated clamp value for a clamp_id. This operation is required only when it's dequeued the last task of a clamp bucket tracking the current MAX aggregated clamp value. In this case, the CPU is either entering IDLE or going to schedule a less boosted or more clamped task. The expected number of different clamp values configured at build time is small enough to fit the full unordered array into a single cache line, for configurations of up to 7 buckets. Add to struct rq the basic data structures required to refcount the number of RUNNABLE tasks for each clamp bucket. Add also the max aggregation required to update the rq's clamp value at each enqueue/dequeue event. Use a simple linear mapping of clamp values into clamp buckets. Pre-compute and cache bucket_id to avoid integer divisions at enqueue/dequeue time. Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alessio Balsini <balsini@android.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten Rasmussen <morten.rasmussen@arm.com> Cc: Paul Turner <pjt@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Perret <quentin.perret@arm.com> Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com> Cc: Steve Muckle <smuckle@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Todd Kjos <tkjos@google.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Link: https://lkml.kernel.org/r/20190621084217.8167-2-patrick.bellasi@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-20block: rename CONFIG_DEBUG_BLK_CGROUP to CONFIG_BFQ_CGROUP_DEBUGChristoph Hellwig
This option is entirely bfq specific, give it an appropinquate name. Also make it depend on CONFIG_BFQ_GROUP_IOSCHED in Kconfig, as all the functionality already does so anyway. Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-17Merge tag 'v5.2-rc5' into sched/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-17Merge tag 'v5.2-rc5' into locking/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-15kbuild: add support for ensuring headers are self-containedJani Nikula
Sometimes it's useful to be able to explicitly ensure certain headers remain self-contained, i.e. that they are compilable as standalone units, by including and/or forward declaring everything they depend on. Add special target header-test-y where individual Makefiles can add headers to be tested if CONFIG_HEADER_TEST is enabled. This will generate a dummy C file per header that gets built as part of extra-y. Signed-off-by: Jani Nikula <jani.nikula@intel.com> Reviewed-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-06-14docs: scheduler: convert docs to ReST and rename to *.rstMauro Carvalho Chehab
In order to prepare to add them to the Kernel API book, convert the files to ReST format. The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-14docs: cgroup-v1: convert docs to ReST and rename to *.rstMauro Carvalho Chehab
Convert the cgroup-v1 files to ReST format, in order to allow a later addition to the admin-guide. The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2019-06-08Merge tag 'char-misc-5.2-rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc driver fixes from Greg KH: "Here are some small char and misc driver fixes for 5.2-rc4 to resolve a number of reported issues. The most "notable" one here is the kernel headers in proc^Wsysfs fixes. Those changes move the header file info into sysfs and fixes the build issues that you reported. Other than that, a bunch of small habanalabs driver fixes, some fpga driver fixes, and a few other tiny driver fixes. All of these have been in linux-next for a while with no reported issues" * tag 'char-misc-5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: habanalabs: Read upper bits of trace buffer from RWPHI habanalabs: Fix virtual address access via debugfs for 2MB pages fpga: zynqmp-fpga: Correctly handle error pointer habanalabs: fix bug in checking huge page optimization habanalabs: Avoid using a non-initialized MMU cache mutex habanalabs: fix debugfs code uapi/habanalabs: add opcode for enable/disable device debug mode habanalabs: halt debug engines on user process close test_firmware: Use correct snprintf() limit genwqe: Prevent an integer overflow in the ioctl parport: Fix mem leak in parport_register_dev_model fpga: dfl: expand minor range when registering chrdev region fpga: dfl: Add lockdep classes for pdata->lock fpga: dfl: afu: Pass the correct device to dma_mapping_error() fpga: stratix10-soc: fix use-after-free on s10_init() w1: ds2408: Fix typo after 49695ac46861 (reset on output_write retry with readback) kheaders: Do not regenerate archive if config is not changed kheaders: Move from proc to sysfs lkdtm/bugs: Adjust recursion test to avoid elision lkdtm/usercopy: Moves the KERNEL_DS test to non-canonical
2019-06-03locking/lockdep: Define INITIAL_CHAIN_KEY for chain keys to start withYuyang Du
Chain keys are computed using Jenkins hash function, which needs an initial hash to start with. Dedicate a macro to make this clear and configurable. A later patch changes this initial chain key. Signed-off-by: Yuyang Du <duyuyang@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bvanassche@acm.org Cc: frederic@kernel.org Cc: ming.lei@redhat.com Cc: will.deacon@arm.com Link: https://lkml.kernel.org/r/20190506081939.74287-9-duyuyang@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-03locking/lockdep: Use lockdep_init_task for task initiation consistentlyYuyang Du
Despite that there is a lockdep_init_task() which does nothing, lockdep initiates tasks by assigning lockdep fields and does so inconsistently. Fix this by using lockdep_init_task(). Signed-off-by: Yuyang Du <duyuyang@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bvanassche@acm.org Cc: frederic@kernel.org Cc: ming.lei@redhat.com Cc: will.deacon@arm.com Link: https://lkml.kernel.org/r/20190506081939.74287-8-duyuyang@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-03sched/core: Provide a pointer to the valid CPU maskSebastian Andrzej Siewior
In commit: 4b53a3412d66 ("sched/core: Remove the tsk_nr_cpus_allowed() wrapper") the tsk_nr_cpus_allowed() wrapper was removed. There was not much difference in !RT but in RT we used this to implement migrate_disable(). Within a migrate_disable() section the CPU mask is restricted to single CPU while the "normal" CPU mask remains untouched. As an alternative implementation Ingo suggested to use: struct task_struct { const cpumask_t *cpus_ptr; cpumask_t cpus_mask; }; with t->cpus_ptr = &t->cpus_mask; In -RT we then can switch the cpus_ptr to: t->cpus_ptr = &cpumask_of(task_cpu(p)); in a migration disabled region. The rules are simple: - Code that 'uses' ->cpus_allowed would use the pointer. - Code that 'modifies' ->cpus_allowed would use the direct mask. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190423142636.14347-1-bigeasy@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 167Thomas Gleixner
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation version 2 of the license this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 83 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070034.021731668@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-24kheaders: Move from proc to sysfsJoel Fernandes (Google)
The kheaders archive consisting of the kernel headers used for compiling bpf programs is in /proc. However there is concern that moving it here will make it permanent. Let us move it to /sys/kernel as discussed [1]. [1] https://lore.kernel.org/patchwork/patch/1067310/#1265969 Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21treewide: Add SPDX license identifier - Makefile/KconfigThomas Gleixner
Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21treewide: Add SPDX license identifier for missed filesThomas Gleixner
Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-18initramfs: don't free a non-existent initrdSteven Price
Since commit 54c7a8916a88 ("initramfs: free initrd memory if opening /initrd.image fails"), the kernel has unconditionally attempted to free the initrd even if it doesn't exist. In the non-existent case this causes a boot-time splat if CONFIG_DEBUG_VIRTUAL is enabled due to a call to virt_to_phys() with a NULL address. Instead we should check that the initrd actually exists and only attempt to free it if it does. Link: http://lkml.kernel.org/r/20190516143125.48948-1-steven.price@arm.com Fixes: 54c7a8916a88 ("initramfs: free initrd memory if opening /initrd.image fails") Signed-off-by: Steven Price <steven.price@arm.com> Reported-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14mm: shuffle initial free memory to improve memory-side-cache utilizationDan Williams
Patch series "mm: Randomize free memory", v10. This patch (of 3): Randomization of the page allocator improves the average utilization of a direct-mapped memory-side-cache. Memory side caching is a platform capability that Linux has been previously exposed to in HPC (high-performance computing) environments on specialty platforms. In that instance it was a smaller pool of high-bandwidth-memory relative to higher-capacity / lower-bandwidth DRAM. Now, this capability is going to be found on general purpose server platforms where DRAM is a cache in front of higher latency persistent memory [1]. Robert offered an explanation of the state of the art of Linux interactions with memory-side-caches [2], and I copy it here: It's been a problem in the HPC space: http://www.nersc.gov/research-and-development/knl-cache-mode-performance-coe/ A kernel module called zonesort is available to try to help: https://software.intel.com/en-us/articles/xeon-phi-software and this abandoned patch series proposed that for the kernel: https://lkml.kernel.org/r/20170823100205.17311-1-lukasz.daniluk@intel.com Dan's patch series doesn't attempt to ensure buffers won't conflict, but also reduces the chance that the buffers will. This will make performance more consistent, albeit slower than "optimal" (which is near impossible to attain in a general-purpose kernel). That's better than forcing users to deploy remedies like: "To eliminate this gradual degradation, we have added a Stream measurement to the Node Health Check that follows each job; nodes are rebooted whenever their measured memory bandwidth falls below 300 GB/s." A replacement for zonesort was merged upstream in commit cc9aec03e58f ("x86/numa_emulation: Introduce uniform split capability"). With this numa_emulation capability, memory can be split into cache sized ("near-memory" sized) numa nodes. A bind operation to such a node, and disabling workloads on other nodes, enables full cache performance. However, once the workload exceeds the cache size then cache conflicts are unavoidable. While HPC environments might be able to tolerate time-scheduling of cache sized workloads, for general purpose server platforms, the oversubscribed cache case will be the common case. The worst case scenario is that a server system owner benchmarks a workload at boot with an un-contended cache only to see that performance degrade over time, even below the average cache performance due to excessive conflicts. Randomization clips the peaks and fills in the valleys of cache utilization to yield steady average performance. Here are some performance impact details of the patches: 1/ An Intel internal synthetic memory bandwidth measurement tool, saw a 3X speedup in a contrived case that tries to force cache conflicts. The contrived cased used the numa_emulation capability to force an instance of the benchmark to be run in two of the near-memory sized numa nodes. If both instances were placed on the same emulated they would fit and cause zero conflicts. While on separate emulated nodes without randomization they underutilized the cache and conflicted unnecessarily due to the in-order allocation per node. 2/ A well known Java server application benchmark was run with a heap size that exceeded cache size by 3X. The cache conflict rate was 8% for the first run and degraded to 21% after page allocator aging. With randomization enabled the rate levelled out at 11%. 3/ A MongoDB workload did not observe measurable difference in cache-conflict rates, but the overall throughput dropped by 7% with randomization in one case. 4/ Mel Gorman ran his suite of performance workloads with randomization enabled on platforms without a memory-side-cache and saw a mix of some improvements and some losses [3]. While there is potentially significant improvement for applications that depend on low latency access across a wide working-set, the performance may be negligible to negative for other workloads. For this reason the shuffle capability defaults to off unless a direct-mapped memory-side-cache is detected. Even then, the page_alloc.shuffle=0 parameter can be specified to disable the randomization on those systems. Outside of memory-side-cache utilization concerns there is potentially security benefit from randomization. Some data exfiltration and return-oriented-programming attacks rely on the ability to infer the location of sensitive data objects. The kernel page allocator, especially early in system boot, has predictable first-in-first out behavior for physical pages. Pages are freed in physical address order when first onlined. Quoting Kees: "While we already have a base-address randomization (CONFIG_RANDOMIZE_MEMORY), attacks against the same hardware and memory layouts would certainly be using the predictability of allocation ordering (i.e. for attacks where the base address isn't important: only the relative positions between allocated memory). This is common in lots of heap-style attacks. They try to gain control over ordering by spraying allocations, etc. I'd really like to see this because it gives us something similar to CONFIG_SLAB_FREELIST_RANDOM but for the page allocator." While SLAB_FREELIST_RANDOM reduces the predictability of some local slab caches it leaves vast bulk of memory to be predictably in order allocated. However, it should be noted, the concrete security benefits are hard to quantify, and no known CVE is mitigated by this randomization. Introduce shuffle_free_memory(), and its helper shuffle_zone(), to perform a Fisher-Yates shuffle of the page allocator 'free_area' lists when they are initially populated with free memory at boot and at hotplug time. Do this based on either the presence of a page_alloc.shuffle=Y command line parameter, or autodetection of a memory-side-cache (to be added in a follow-on patch). The shuffling is done in terms of CONFIG_SHUFFLE_PAGE_ORDER sized free pages where the default CONFIG_SHUFFLE_PAGE_ORDER is MAX_ORDER-1 i.e. 10, 4MB this trades off randomization granularity for time spent shuffling. MAX_ORDER-1 was chosen to be minimally invasive to the page allocator while still showing memory-side cache behavior improvements, and the expectation that the security implications of finer granularity randomization is mitigated by CONFIG_SLAB_FREELIST_RANDOM. The performance impact of the shuffling appears to be in the noise compared to other memory initialization work. This initial randomization can be undone over time so a follow-on patch is introduced to inject entropy on page free decisions. It is reasonable to ask if the page free entropy is sufficient, but it is not enough due to the in-order initial freeing of pages. At the start of that process putting page1 in front or behind page0 still keeps them close together, page2 is still near page1 and has a high chance of being adjacent. As more pages are added ordering diversity improves, but there is still high page locality for the low address pages and this leads to no significant impact to the cache conflict rate. [1]: https://itpeernetwork.intel.com/intel-optane-dc-persistent-memory-operating-modes/ [2]: https://lkml.kernel.org/r/AT5PR8401MB1169D656C8B5E121752FC0F8AB120@AT5PR8401MB1169.NAMPRD84.PROD.OUTLOOK.COM [3]: https://lkml.org/lkml/2018/10/12/309 [dan.j.williams@intel.com: fix shuffle enable] Link: http://lkml.kernel.org/r/154943713038.3858443.4125180191382062871.stgit@dwillia2-desk3.amr.corp.intel.com [cai@lca.pw: fix SHUFFLE_PAGE_ALLOCATOR help texts] Link: http://lkml.kernel.org/r/20190425201300.75650-1-cai@lca.pw Link: http://lkml.kernel.org/r/154899811738.3165233.12325692939590944259.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Qian Cai <cai@lca.pw> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Keith Busch <keith.busch@intel.com> Cc: Robert Elliott <elliott@hpe.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14init: free_initmem: poison freed init memoryMike Rapoport
Various architectures including x86 poison the freed init memory. Do the same in the generic free_initmem implementation and switch sparc32 architecture that is identical to the generic code over to it now. Link: http://lkml.kernel.org/r/1550515285-17446-4-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Richard Kuo <rkuo@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14init: provide a generic free_initmem implementationMike Rapoport
Patch series "provide a generic free_initmem implementation", v2. Many architectures implement free_initmem() in exactly the same or very similar way: they wrap the call to free_initmem_default() with sometimes different 'poison' parameter. These patches switch those architectures to use a generic implementation that does free_initmem_default(POISON_FREE_INITMEM). This was inspired by Christoph's patches for free_initrd_mem [1] and I shamelessly copied changelog entries from his patches :) [1] https://lore.kernel.org/lkml/20190213174621.29297-1-hch@lst.de/ This patch (of 2): For most architectures free_initmem just a wrapper for the same free_initmem_default(-1) call. Provide that as a generic implementation marked __weak. Link: http://lkml.kernel.org/r/1550515285-17446-2-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Richard Kuo <rkuo@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14initramfs: poison freed initrd memoryChristoph Hellwig
Various architectures including x86 poison the freed initrd memory. Do the same in the generic free_initrd_mem implementation and switch a few more architectures that are identical to the generic code over to it now. Link: http://lkml.kernel.org/r/20190213174621.29297-9-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> [arm64] Cc: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Cc: Steven Price <steven.price@arm.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14initramfs: provide a generic free_initrd_mem implementationChristoph Hellwig
For most architectures free_initrd_mem just expands to the same free_reserved_area call. Provide that as a generic implementation marked __weak. Link: http://lkml.kernel.org/r/20190213174621.29297-8-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Acked-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> [arm64] Cc: Steven Price <steven.price@arm.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14initramfs: move the legacy keepinitrd parameter to core codeChristoph Hellwig
No need to handle the freeing disable in arch code when we already have a core hook (and a different name for the option) for it. Link: http://lkml.kernel.org/r/20190213174621.29297-7-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64] Acked-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Cc: Steven Price <steven.price@arm.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>