Commit Graph

39726 Commits

Author SHA1 Message Date
Linus Torvalds
f42e1e3e40 audit/stable-6.0 PR 20220801
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Merge tag 'audit-pr-20220801' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit

Pull audit updates from Paul Moore:
 "Two minor audit patches: on marks a function as static, the other
  removes a redundant length check"

* tag 'audit-pr-20220801' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
  audit: make is_audit_feature_set() static
  audit: remove redundant data_len check
2022-08-02 14:56:25 -07:00
Linus Torvalds
d7b767b508 execve updates for v5.20-rc1
- Allow unsharing time namespace on vfork+exec (Andrei Vagin)
 
 - Replace usage of deprecated kmap APIs (Fabio M. De Francesco)
 
 - Fix spelling mistake (Zhang Jiaming)
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Merge tag 'execve-v5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull execve updates from Kees Cook:

 - Allow unsharing time namespace on vfork+exec (Andrei Vagin)

 - Replace usage of deprecated kmap APIs (Fabio M. De Francesco)

 - Fix spelling mistake (Zhang Jiaming)

* tag 'execve-v5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  exec: Call kmap_local_page() in copy_string_kernel()
  exec: Fix a spelling mistake
  selftests/timens: add a test for vfork+exit
  fs/exec: allow to unshare a time namespace on vfork+exec
2022-08-02 14:36:19 -07:00
Jason A. Donenfeld
151c8e499f wireguard: ratelimiter: use hrtimer in selftest
Using msleep() is problematic because it's compared against
ratelimiter.c's ktime_get_coarse_boottime_ns(), which means on systems
with slow jiffies (such as UML's forced HZ=100), the result is
inaccurate. So switch to using schedule_hrtimeout().

However, hrtimer gives us access only to the traditional posix timers,
and none of the _COARSE variants. So now, rather than being too
imprecise like jiffies, it's too precise.

One solution would be to give it a large "range" value, but this will
still fire early on a loaded system. A better solution is to align the
timeout to the actual coarse timer, and then round up to the nearest
tick, plus change.

So add the timeout to the current coarse time, and then
schedule_hrtimer() until the absolute computed time.

This should hopefully reduce flakes in CI as well. Note that we keep the
retry loop in case the entire function is running behind, because the
test could still be scheduled out, by either the kernel or by the
hypervisor's kernel, in which case restarting the test and hoping to not
be scheduled out still helps.

Fixes: e7096c131e ("net: WireGuard secure network tunnel")
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-02 13:47:50 -07:00
Linus Torvalds
c013d0af81 for-5.20/block-2022-07-29
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Merge tag 'for-5.20/block-2022-07-29' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:

 - Improve the type checking of request flags (Bart)

 - Ensure queue mapping for a single queues always picks the right queue
   (Bart)

 - Sanitize the io priority handling (Jan)

 - rq-qos race fix (Jinke)

 - Reserved tags handling improvements (John)

 - Separate memory alignment from file/disk offset aligment for O_DIRECT
   (Keith)

 - Add new ublk driver, userspace block driver using io_uring for
   communication with the userspace backend (Ming)

 - Use try_cmpxchg() to cleanup the code in various spots (Uros)

 - Finally remove bdevname() (Christoph)

 - Clean up the zoned device handling (Christoph)

 - Clean up independent access range support (Christoph)

 - Clean up and improve block sysfs handling (Christoph)

 - Clean up and improve teardown of block devices.

   This turns the usual two step process into something that is simpler
   to implement and handle in block drivers (Christoph)

 - Clean up chunk size handling (Christoph)

 - Misc cleanups and fixes (Bart, Bo, Dan, GuoYong, Jason, Keith, Liu,
   Ming, Sebastian, Yang, Ying)

* tag 'for-5.20/block-2022-07-29' of git://git.kernel.dk/linux-block: (178 commits)
  ublk_drv: fix double shift bug
  ublk_drv: make sure that correct flags(features) returned to userspace
  ublk_drv: fix error handling of ublk_add_dev
  ublk_drv: fix lockdep warning
  block: remove __blk_get_queue
  block: call blk_mq_exit_queue from disk_release for never added disks
  blk-mq: fix error handling in __blk_mq_alloc_disk
  ublk: defer disk allocation
  ublk: rewrite ublk_ctrl_get_queue_affinity to not rely on hctx->cpumask
  ublk: fold __ublk_create_dev into ublk_ctrl_add_dev
  ublk: cleanup ublk_ctrl_uring_cmd
  ublk: simplify ublk_ch_open and ublk_ch_release
  ublk: remove the empty open and release block device operations
  ublk: remove UBLK_IO_F_PREFLUSH
  ublk: add a MAINTAINERS entry
  block: don't allow the same type rq_qos add more than once
  mmc: fix disk/queue leak in case of adding disk failure
  ublk_drv: fix an IS_ERR() vs NULL check
  ublk: remove UBLK_IO_F_INTEGRITY
  ublk_drv: remove unneeded semicolon
  ...
2022-08-02 13:46:35 -07:00
Linus Torvalds
b349b1181d for-5.20/io_uring-2022-07-29
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Merge tag 'for-5.20/io_uring-2022-07-29' of git://git.kernel.dk/linux-block

Pull io_uring updates from Jens Axboe:

 - As per (valid) complaint in the last merge window, fs/io_uring.c has
   grown quite large these days. io_uring isn't really tied to fs
   either, as it supports a wide variety of functionality outside of
   that.

   Move the code to io_uring/ and split it into files that either
   implement a specific request type, and split some code into helpers
   as well. The code is organized a lot better like this, and io_uring.c
   is now < 4K LOC (me).

 - Deprecate the epoll_ctl opcode. It'll still work, just trigger a
   warning once if used. If we don't get any complaints on this, and I
   don't expect any, then we can fully remove it in a future release
   (me).

 - Improve the cancel hash locking (Hao)

 - kbuf cleanups (Hao)

 - Efficiency improvements to the task_work handling (Dylan, Pavel)

 - Provided buffer improvements (Dylan)

 - Add support for recv/recvmsg multishot support. This is similar to
   the accept (or poll) support for have for multishot, where a single
   SQE can trigger everytime data is received. For applications that
   expect to do more than a few receives on an instantiated socket, this
   greatly improves efficiency (Dylan).

 - Efficiency improvements for poll handling (Pavel)

 - Poll cancelation improvements (Pavel)

 - Allow specifiying a range for direct descriptor allocations (Pavel)

 - Cleanup the cqe32 handling (Pavel)

 - Move io_uring types to greatly cleanup the tracing (Pavel)

 - Tons of great code cleanups and improvements (Pavel)

 - Add a way to do sync cancelations rather than through the sqe -> cqe
   interface, as that's a lot easier to use for some use cases (me).

 - Add support to IORING_OP_MSG_RING for sending direct descriptors to a
   different ring. This avoids the usually problematic SCM case, as we
   disallow those. (me)

 - Make the per-command alloc cache we use for apoll generic, place
   limits on it, and use it for netmsg as well (me).

 - Various cleanups (me, Michal, Gustavo, Uros)

* tag 'for-5.20/io_uring-2022-07-29' of git://git.kernel.dk/linux-block: (172 commits)
  io_uring: ensure REQ_F_ISREG is set async offload
  net: fix compat pointer in get_compat_msghdr()
  io_uring: Don't require reinitable percpu_ref
  io_uring: fix types in io_recvmsg_multishot_overflow
  io_uring: Use atomic_long_try_cmpxchg in __io_account_mem
  io_uring: support multishot in recvmsg
  net: copy from user before calling __get_compat_msghdr
  net: copy from user before calling __copy_msghdr
  io_uring: support 0 length iov in buffer select in compat
  io_uring: fix multishot ending when not polled
  io_uring: add netmsg cache
  io_uring: impose max limit on apoll cache
  io_uring: add abstraction around apoll cache
  io_uring: move apoll cache to poll.c
  io_uring: consolidate hash_locked io-wq handling
  io_uring: clear REQ_F_HASH_LOCKED on hash removal
  io_uring: don't race double poll setting REQ_F_ASYNC_DATA
  io_uring: don't miss setting REQ_F_DOUBLE_POLL
  io_uring: disable multishot recvmsg
  io_uring: only trace one of complete or overflow
  ...
2022-08-02 13:20:44 -07:00
Masami Hiramatsu (Google)
2f63e5d2e3 tracing/eprobe: Show syntax error logs in error_log file
Show the syntax errors for event probes in error_log file as same as
other dynamic events, so that user can understand what is the problem.

Link: https://lkml.kernel.org/r/165932113556.2850673.3483079297896607612.stgit@devnote2

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-08-02 15:22:55 -04:00
Zhiqiang Liu
59927cbe3f tracing: Use free_trace_buffer() in allocate_trace_buffers()
In allocate_trace_buffers(), if allocating tr->max_buffer
fails, we can directly call free_trace_buffer to free
tr->array_buffer.

Link: https://lkml.kernel.org/r/65f0702d-07f6-08de-2a07-4c50af56a67b@huawei.com

Signed-off-by: Zhiqiang Liu <liuzhiqiang26@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-08-02 15:13:19 -04:00
Linus Torvalds
a771ea6413 Power management updates for 5.20-rc1
- Make cpufreq_show_cpus() more straightforward (Viresh Kumar).
 
  - Drop unnecessary CPU hotplug locking from store() used by cpufreq
    sysfs attributes (Viresh Kumar).
 
  - Make the ACPI cpufreq driver support the boost control interface on
    Zhaoxin/Centaur processors (Tony W Wang-oc).
 
  - Print a warning message on attempts to free an active cpufreq policy
    which should never happen (Viresh Kumar).
 
  - Fix grammar in the Kconfig help text for the loongson2 cpufreq
    driver (Randy Dunlap).
 
  - Use cpumask_var_t for an on-stack CPU mask in the ondemand cpufreq
    governor (Zhao Liu).
 
  - Add trace points for guest_halt_poll_ns grow/shrink to the haltpoll
    cpuidle driver (Eiichi Tsukata).
 
  - Modify intel_idle to treat C1 and C1E as independent idle states on
    Sapphire Rapids (Artem Bityutskiy).
 
  - Extend support for wakeirq to callback wrappers used during system
    suspend and resume (Ulf Hansson).
 
  - Defer waiting for device probe before loading a hibernation image
    till the first actual device access to avoid possible deadlocks
    reported by syzbot (Tetsuo Handa).
 
  - Unify device_init_wakeup() for PM_SLEEP and !PM_SLEEP (Bjorn
    Helgaas).
 
  - Add Raptor Lake-P to the list of processors supported by the Intel
    RAPL driver (George D Sworo).
 
  - Add Alder Lake-N and Raptor Lake-P to the list of processors for
    which Power Limit4 is supported in the Intel RAPL driver (Sumeet
    Pawnikar).
 
  - Make pm_genpd_remove() check genpd_debugfs_dir against NULL before
    attempting to remove it (Hsin-Yi Wang).
 
  - Change the Energy Model code to represent power in micro-Watts and
    adjust its users accordingly (Lukasz Luba).
 
  - Add new devfreq driver for Mediatek CCI (Cache Coherent
    Interconnect) (Johnson Wang).
 
  - Convert the Samsung Exynos SoC Bus bindings to DT schema of
    exynos-bus.c (Krzysztof Kozlowski).
 
  - Address kernel-doc warnings by adding the description for unused
    fucntion parameters in devfreq core (Mauro Carvalho Chehab).
 
  - Use NULL to pass a null pointer rather than zero according to the
    function propotype in imx-bus.c (Colin Ian King).
 
  - Print error message instead of error interger value in
    tegra30-devfreq.c (Dmitry Osipenko).
 
  - Add checks to prevent setting negative frequency QoS limits for
    CPUs (Shivnandan Kumar).
 
  - Update the pm-graph suite of utilities to the latest revision 5.9
    including multiple improvements (Todd Brandt).
 
  - Drop pme_interrupt reference from the PCI power management
    documentation (Mario Limonciello).
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Merge tag 'pm-5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management updates from Rafael Wysocki:
 "These are mostly minor improvements all over including new CPU IDs for
  the Intel RAPL driver, an Energy Model rework to use micro-Watt as the
  power unit, cpufreq fixes and cleanus, cpuidle updates, devfreq
  updates, documentation cleanups and a new version of the pm-graph
  suite of utilities.

  Specifics:

   - Make cpufreq_show_cpus() more straightforward (Viresh Kumar).

   - Drop unnecessary CPU hotplug locking from store() used by cpufreq
     sysfs attributes (Viresh Kumar).

   - Make the ACPI cpufreq driver support the boost control interface on
     Zhaoxin/Centaur processors (Tony W Wang-oc).

   - Print a warning message on attempts to free an active cpufreq
     policy which should never happen (Viresh Kumar).

   - Fix grammar in the Kconfig help text for the loongson2 cpufreq
     driver (Randy Dunlap).

   - Use cpumask_var_t for an on-stack CPU mask in the ondemand cpufreq
     governor (Zhao Liu).

   - Add trace points for guest_halt_poll_ns grow/shrink to the haltpoll
     cpuidle driver (Eiichi Tsukata).

   - Modify intel_idle to treat C1 and C1E as independent idle states on
     Sapphire Rapids (Artem Bityutskiy).

   - Extend support for wakeirq to callback wrappers used during system
     suspend and resume (Ulf Hansson).

   - Defer waiting for device probe before loading a hibernation image
     till the first actual device access to avoid possible deadlocks
     reported by syzbot (Tetsuo Handa).

   - Unify device_init_wakeup() for PM_SLEEP and !PM_SLEEP (Bjorn
     Helgaas).

   - Add Raptor Lake-P to the list of processors supported by the Intel
     RAPL driver (George D Sworo).

   - Add Alder Lake-N and Raptor Lake-P to the list of processors for
     which Power Limit4 is supported in the Intel RAPL driver (Sumeet
     Pawnikar).

   - Make pm_genpd_remove() check genpd_debugfs_dir against NULL before
     attempting to remove it (Hsin-Yi Wang).

   - Change the Energy Model code to represent power in micro-Watts and
     adjust its users accordingly (Lukasz Luba).

   - Add new devfreq driver for Mediatek CCI (Cache Coherent
     Interconnect) (Johnson Wang).

   - Convert the Samsung Exynos SoC Bus bindings to DT schema of
     exynos-bus.c (Krzysztof Kozlowski).

   - Address kernel-doc warnings by adding the description for unused
     function parameters in devfreq core (Mauro Carvalho Chehab).

   - Use NULL to pass a null pointer rather than zero according to the
     function propotype in imx-bus.c (Colin Ian King).

   - Print error message instead of error interger value in
     tegra30-devfreq.c (Dmitry Osipenko).

   - Add checks to prevent setting negative frequency QoS limits for
     CPUs (Shivnandan Kumar).

   - Update the pm-graph suite of utilities to the latest revision 5.9
     including multiple improvements (Todd Brandt).

   - Drop pme_interrupt reference from the PCI power management
     documentation (Mario Limonciello)"

* tag 'pm-5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (27 commits)
  powercap: RAPL: Add Power Limit4 support for Alder Lake-N and Raptor Lake-P
  PM: QoS: Add check to make sure CPU freq is non-negative
  PM: hibernate: defer device probing when resuming from hibernation
  intel_idle: make SPR C1 and C1E be independent
  cpufreq: ondemand: Use cpumask_var_t for on-stack cpu mask
  cpufreq: loongson2: fix Kconfig "its" grammar
  pm-graph v5.9
  cpufreq: Warn users while freeing active policy
  cpufreq: scmi: Support the power scale in micro-Watts in SCMI v3.1
  firmware: arm_scmi: Get detailed power scale from perf
  Documentation: EM: Switch to micro-Watts scale
  PM: EM: convert power field to micro-Watts precision and align drivers
  PM / devfreq: tegra30: Add error message for devm_devfreq_add_device()
  PM / devfreq: imx-bus: use NULL to pass a null pointer rather than zero
  PM / devfreq: shut up kernel-doc warnings
  dt-bindings: interconnect: samsung,exynos-bus: convert to dtschema
  PM / devfreq: mediatek: Introduce MediaTek CCI devfreq driver
  dt-bindings: interconnect: Add MediaTek CCI dt-bindings
  PM: domains: Ensure genpd_debugfs_dir exists before remove
  PM: runtime: Extend support for wakeirq for force_suspend|resume
  ...
2022-08-02 11:17:00 -07:00
Chen Zhongjin
28f6c37a29 kprobes: Forbid probing on trampoline and BPF code areas
kernel_text_address() treats ftrace_trampoline, kprobe_insn_slot
and bpf_text_address as valid kprobe addresses - which is not ideal.

These text areas are removable and changeable without any notification
to kprobes, and probing on them can trigger unexpected behavior:

  https://lkml.org/lkml/2022/7/26/1148

Considering that jump_label and static_call text are already
forbiden to probe, kernel_text_address() should be replaced with
core_kernel_text() and is_module_text_address() to check other text
areas which are unsafe to kprobe.

[ mingo: Rewrote the changelog. ]

Fixes: 5b485629ba ("kprobes, extable: Identify kprobes trampolines as kernel text area")
Fixes: 74451e66d5 ("bpf: make jited programs visible in traces")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20220801033719.228248-1-chenzhongjin@huawei.com
2022-08-02 11:47:29 +02:00
Linus Torvalds
9de1f9c8ca Updates for interrupt core and drivers:
core:
    - Fix a few inconsistencies between UP and SMP vs. interrupt affinities
    - Small updates and cleanups all over the place
 
  drivers:
    - New driver for the LoongArch interrupt controller
    - New driver for the Renesas RZ/G2L interrupt controller
 
    - Hotpath optimization for SiFive PLIC
    - Workaround for broken PLIC edge triggered interrupts
 
    - Simall cleanups and improvements as usual
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Merge tag 'irq-core-2022-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq updates from Thomas Gleixner:
 "Updates for interrupt core and drivers:

  Core:

   - Fix a few inconsistencies between UP and SMP vs interrupt
     affinities

   - Small updates and cleanups all over the place

  New drivers:

   - LoongArch interrupt controller

   - Renesas RZ/G2L interrupt controller

  Updates:

   - Hotpath optimization for SiFive PLIC

   - Workaround for broken PLIC edge triggered interrupts

   - Simall cleanups and improvements as usual"

* tag 'irq-core-2022-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits)
  irqchip/mmp: Declare init functions in common header file
  irqchip/mips-gic: Check the return value of ioremap() in gic_of_init()
  genirq: Use for_each_action_of_desc in actions_show()
  irqchip / ACPI: Introduce ACPI_IRQ_MODEL_LPIC for LoongArch
  irqchip: Add LoongArch CPU interrupt controller support
  irqchip: Add Loongson Extended I/O interrupt controller support
  irqchip/loongson-liointc: Add ACPI init support
  irqchip/loongson-pch-msi: Add ACPI init support
  irqchip/loongson-pch-pic: Add ACPI init support
  irqchip: Add Loongson PCH LPC controller support
  LoongArch: Prepare to support multiple pch-pic and pch-msi irqdomain
  LoongArch: Use ACPI_GENERIC_GSI for gsi handling
  genirq/generic_chip: Export irq_unmap_generic_chip
  ACPI: irq: Allow acpi_gsi_to_irq() to have an arch-specific fallback
  APCI: irq: Add support for multiple GSI domains
  LoongArch: Provisionally add ACPICA data structures
  irqdomain: Use hwirq_max instead of revmap_size for NOMAP domains
  irqdomain: Report irq number for NOMAP domains
  irqchip/gic-v3: Fix comment typo
  dt-bindings: interrupt-controller: renesas,rzg2l-irqc: Document RZ/V2L SoC
  ...
2022-08-01 12:48:15 -07:00
Linus Torvalds
63e6053add Perf events updates for this cycle are:
- Fix Intel Alder Lake PEBS memory access latency & data source profiling info bugs.
 
 - Use Intel large-PEBS hardware feature in more circumstances, to reduce
   PMI overhead & reduce sampling data.
 
 - Extend the lost-sample profiling output with the PERF_FORMAT_LOST ABI variant,
   which tells tooling the exact number of samples lost.
 
 - Add new IBS register bits definitions.
 
 - AMD uncore events: Add PerfMonV2 DF (Data Fabric) enhancements.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-core-2022-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf events updates from Ingo Molnar:

 - Fix Intel Alder Lake PEBS memory access latency & data source
   profiling info bugs.

 - Use Intel large-PEBS hardware feature in more circumstances, to
   reduce PMI overhead & reduce sampling data.

 - Extend the lost-sample profiling output with the PERF_FORMAT_LOST ABI
   variant, which tells tooling the exact number of samples lost.

 - Add new IBS register bits definitions.

 - AMD uncore events: Add PerfMonV2 DF (Data Fabric) enhancements.

* tag 'perf-core-2022-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/ibs: Add new IBS register bits into header
  perf/x86/intel: Fix PEBS data source encoding for ADL
  perf/x86/intel: Fix PEBS memory access info encoding for ADL
  perf/core: Add a new read format to get a number of lost samples
  perf/x86/amd/uncore: Add PerfMonV2 RDPMC assignments
  perf/x86/amd/uncore: Add PerfMonV2 DF event format
  perf/x86/amd/uncore: Detect available DF counters
  perf/x86/amd/uncore: Use attr_update for format attributes
  perf/x86/amd/uncore: Use dynamic events array
  x86/events/intel/ds: Enable large PEBS for PERF_SAMPLE_WEIGHT_TYPE
2022-08-01 12:24:30 -07:00
Linus Torvalds
22a39c3d86 This was a fairly quiet cycle for the locking subsystem:
- lockdep: Fix a handful of the more complex lockdep_init_map_*() primitives
    that can lose the lock_type & cause false reports. No such mishap was
    observed in the wild.
 
  - jump_label improvements: simplify the cross-arch support of
    initial NOP patching by making it arch-specific code (used on MIPS only),
    and remove the s390 initial NOP patching that was superfluous.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'locking-core-2022-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking updates from Ingo Molnar:
 "This was a fairly quiet cycle for the locking subsystem:

   - lockdep: Fix a handful of the more complex lockdep_init_map_*()
     primitives that can lose the lock_type & cause false reports. No
     such mishap was observed in the wild.

   - jump_label improvements: simplify the cross-arch support of initial
     NOP patching by making it arch-specific code (used on MIPS only),
     and remove the s390 initial NOP patching that was superfluous"

* tag 'locking-core-2022-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/lockdep: Fix lockdep_init_map_*() confusion
  jump_label: make initial NOP patching the special case
  jump_label: mips: move module NOP patching into arch code
  jump_label: s390: avoid pointless initial NOP patching
2022-08-01 12:15:27 -07:00
Linus Torvalds
b167fdffe9 This cycle's scheduler updates for v6.0 are:
Load-balancing improvements:
 ============================
 
 - Improve NUMA balancing on AMD Zen systems for affine workloads.
 
 - Improve the handling of reduced-capacity CPUs in load-balancing.
 
 - Energy Model improvements: fix & refine all the energy fairness metrics (PELT),
   and remove the conservative threshold requiring 6% energy savings to
   migrate a task. Doing this improves power efficiency for most workloads,
   and also increases the reliability of energy-efficiency scheduling.
 
 - Optimize/tweak select_idle_cpu() to spend (much) less time searching
   for an idle CPU on overloaded systems. There's reports of several
   milliseconds spent there on large systems with large workloads ...
 
   [ Since the search logic changed, there might be behavioral side effects. ]
 
 - Improve NUMA imbalance behavior. On certain systems
   with spare capacity, initial placement of tasks is non-deterministic,
   and such an artificial placement imbalance can persist for a long time,
   hurting (and sometimes helping) performance.
 
   The fix is to make fork-time task placement consistent with runtime
   NUMA balancing placement.
 
   Note that some performance regressions were reported against this,
   caused by workloads that are not memory bandwith limited, which benefit
   from the artificial locality of the placement bug(s). Mel Gorman's
   conclusion, with which we concur, was that consistency is better than
   random workload benefits from non-deterministic bugs:
 
      "Given there is no crystal ball and it's a tradeoff, I think it's
       better to be consistent and use similar logic at both fork time
       and runtime even if it doesn't have universal benefit."
 
 - Improve core scheduling by fixing a bug in sched_core_update_cookie() that
   caused unnecessary forced idling.
 
 - Improve wakeup-balancing by allowing same-LLC wakeup of idle CPUs for newly
   woken tasks.
 
 - Fix a newidle balancing bug that introduced unnecessary wakeup latencies.
 
 ABI improvements/fixes:
 =======================
 
 - Do not check capabilities and do not issue capability check denial messages
   when a scheduler syscall doesn't require privileges. (Such as increasing niceness.)
 
 - Add forced-idle accounting to cgroups too.
 
 - Fix/improve the RSEQ ABI to not just silently accept unknown flags.
   (No existing tooling is known to have learned to rely on the previous behavior.)
 
 - Depreciate the (unused) RSEQ_CS_FLAG_NO_RESTART_ON_* flags.
 
 Optimizations:
 ==============
 
 - Optimize & simplify leaf_cfs_rq_list()
 
 - Micro-optimize set_nr_{and_not,if}_polling() via try_cmpxchg().
 
 Misc fixes & cleanups:
 ======================
 
 - Fix the RSEQ self-tests on RISC-V and Glibc 2.35 systems.
 
 - Fix a full-NOHZ bug that can in some cases result in the tick not being
   re-enabled when the last SCHED_RT task is gone from a runqueue but there's
   still SCHED_OTHER tasks around.
 
 - Various PREEMPT_RT related fixes.
 
 - Misc cleanups & smaller fixes.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2022-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:
"Load-balancing improvements:

   - Improve NUMA balancing on AMD Zen systems for affine workloads.

   - Improve the handling of reduced-capacity CPUs in load-balancing.

   - Energy Model improvements: fix & refine all the energy fairness
     metrics (PELT), and remove the conservative threshold requiring 6%
     energy savings to migrate a task. Doing this improves power
     efficiency for most workloads, and also increases the reliability
     of energy-efficiency scheduling.

   - Optimize/tweak select_idle_cpu() to spend (much) less time
     searching for an idle CPU on overloaded systems. There's reports of
     several milliseconds spent there on large systems with large
     workloads ...

     [ Since the search logic changed, there might be behavioral side
       effects. ]

   - Improve NUMA imbalance behavior. On certain systems with spare
     capacity, initial placement of tasks is non-deterministic, and such
     an artificial placement imbalance can persist for a long time,
     hurting (and sometimes helping) performance.

     The fix is to make fork-time task placement consistent with runtime
     NUMA balancing placement.

     Note that some performance regressions were reported against this,
     caused by workloads that are not memory bandwith limited, which
     benefit from the artificial locality of the placement bug(s). Mel
     Gorman's conclusion, with which we concur, was that consistency is
     better than random workload benefits from non-deterministic bugs:

        "Given there is no crystal ball and it's a tradeoff, I think
         it's better to be consistent and use similar logic at both fork
         time and runtime even if it doesn't have universal benefit."

   - Improve core scheduling by fixing a bug in
     sched_core_update_cookie() that caused unnecessary forced idling.

   - Improve wakeup-balancing by allowing same-LLC wakeup of idle CPUs
     for newly woken tasks.

   - Fix a newidle balancing bug that introduced unnecessary wakeup
     latencies.

  ABI improvements/fixes:

   - Do not check capabilities and do not issue capability check denial
     messages when a scheduler syscall doesn't require privileges. (Such
     as increasing niceness.)

   - Add forced-idle accounting to cgroups too.

   - Fix/improve the RSEQ ABI to not just silently accept unknown flags.
     (No existing tooling is known to have learned to rely on the
     previous behavior.)

   - Depreciate the (unused) RSEQ_CS_FLAG_NO_RESTART_ON_* flags.

  Optimizations:

   - Optimize & simplify leaf_cfs_rq_list()

   - Micro-optimize set_nr_{and_not,if}_polling() via try_cmpxchg().

  Misc fixes & cleanups:

   - Fix the RSEQ self-tests on RISC-V and Glibc 2.35 systems.

   - Fix a full-NOHZ bug that can in some cases result in the tick not
     being re-enabled when the last SCHED_RT task is gone from a
     runqueue but there's still SCHED_OTHER tasks around.

   - Various PREEMPT_RT related fixes.

   - Misc cleanups & smaller fixes"

* tag 'sched-core-2022-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
  rseq: Kill process when unknown flags are encountered in ABI structures
  rseq: Deprecate RSEQ_CS_FLAG_NO_RESTART_ON_* flags
  sched/core: Fix the bug that task won't enqueue into core tree when update cookie
  nohz/full, sched/rt: Fix missed tick-reenabling bug in dequeue_task_rt()
  sched/core: Always flush pending blk_plug
  sched/fair: fix case with reduced capacity CPU
  sched/core: Use try_cmpxchg in set_nr_{and_not,if}_polling
  sched/core: add forced idle accounting for cgroups
  sched/fair: Remove the energy margin in feec()
  sched/fair: Remove task_util from effective utilization in feec()
  sched/fair: Use the same cpumask per-PD throughout find_energy_efficient_cpu()
  sched/fair: Rename select_idle_mask to select_rq_mask
  sched, drivers: Remove max param from effective_cpu_util()/sched_cpu_util()
  sched/fair: Decay task PELT values during wakeup migration
  sched/fair: Provide u64 read for 32-bits arch helper
  sched/fair: Introduce SIS_UTIL to search idle CPU based on sum of util_avg
  sched: only perform capability check on privileged operation
  sched: Remove unused function group_first_cpu()
  sched/fair: Remove redundant word " *"
  selftests/rseq: check if libc rseq support is registered
  ...
2022-08-01 11:49:06 -07:00
Mathieu Desnoyers
c17a6ff932 rseq: Kill process when unknown flags are encountered in ABI structures
rseq_abi()->flags and rseq_abi()->rseq_cs->flags 29 upper bits are
currently unused.

The current behavior when those bits are set is to ignore them. This is
not an ideal behavior, because when future features will start using
those flags, if user-space fails to correctly validate that the kernel
indeed supports those flags (e.g. with a new sys_rseq flags bit) before
using them, it may incorrectly assume that the kernel will handle those
flags way when in fact those will be silently ignored on older kernels.

Validating that unused flags bits are cleared will allow a smoother
transition when those flags will start to be used by allowing
applications to fail early, and obviously, when they attempt to use the
new flags on an older kernel that does not support them.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20220622194617.1155957-2-mathieu.desnoyers@efficios.com
2022-08-01 15:21:42 +02:00
Mathieu Desnoyers
0190e4198e rseq: Deprecate RSEQ_CS_FLAG_NO_RESTART_ON_* flags
The pretty much unused RSEQ_CS_FLAG_NO_RESTART_ON_* flags introduce
complexity in rseq, and are subtly buggy [1]. Solving those issues
requires introducing additional complexity in the rseq implementation
for each supported architecture.

Considering that it complexifies the rseq ABI, I am proposing that we
deprecate those flags. [2]

So far there appears to be consensus from maintainers of user-space
projects impacted by this feature that its removal would be a welcome
simplification. [3]

The deprecation approach proposed here is to issue WARN_ON_ONCE() when
encountering those flags and kill the offending process with sigsegv.
This should allow us to quickly identify whether anyone yells at us for
removing this.

Link: https://lore.kernel.org/lkml/20220618182515.95831-1-minhquangbui99@gmail.com/ [1]
Link: https://lore.kernel.org/lkml/258546133.12151.1655739550814.JavaMail.zimbra@efficios.com/ [2]
Link: https://lore.kernel.org/lkml/87pmj1enjh.fsf@email.froward.int.ebiederm.org/ [3]
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/lkml/20220622194617.1155957-1-mathieu.desnoyers@efficios.com
2022-08-01 15:21:29 +02:00
Juergen Gross
a870544ca9 kernel: remove platform_has() infrastructure
The only use case of the platform_has() infrastructure has been
removed again, so remove the whole feature.

Signed-off-by: Juergen Gross <jgross@suse.com>
Tested-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> # Arm64 guest using Xen
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Link: https://lore.kernel.org/r/20220622063838.8854-3-jgross@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
2022-08-01 07:42:56 +02:00
Linus Torvalds
89caf57540 - Update the mitigations= kernel param documentation
- Check the IBPB feature flag before enabling IBPB in firmware calls
 because cloud vendors' fantasy when it comes to creating guest
 configurations is unlimited
 
 - Unexport sev_es_ghcb_hv_call() before 5.19 releases now that HyperV
 doesn't need it anymore
 
 - Remove dead CONFIG_* items
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Merge tag 'x86_urgent_for_v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Borislav Petkov:

 - Update the 'mitigations=' kernel param documentation

 - Check the IBPB feature flag before enabling IBPB in firmware calls
   because cloud vendors' fantasy when it comes to creating guest
   configurations is unlimited

 - Unexport sev_es_ghcb_hv_call() before 5.19 releases now that HyperV
   doesn't need it anymore

 - Remove dead CONFIG_* items

* tag 'x86_urgent_for_v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  docs/kernel-parameters: Update descriptions for "mitigations=" param with retbleed
  x86/bugs: Do not enable IBPB at firmware entry when IBPB is not available
  Revert "x86/sev: Expose sev_es_ghcb_hv_call() for use by HyperV"
  x86/configs: Update configs in x86_debug.config
2022-07-31 09:26:53 -07:00
Linus Torvalds
5e4823e6da - Avoid rwsem lockups in certain situations when handling the handoff bit
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Merge tag 'locking_urgent_for_v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking fix from Borislav Petkov:

 - Avoid rwsem lockups in certain situations when handling the handoff
   bit

* tag 'locking_urgent_for_v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/rwsem: Allow slowpath writer to ignore handoff bit if not set by first waiter
2022-07-31 09:21:13 -07:00
Daniel Bristot de Oliveira
e88043c0ac rv/reactor: Add the panic reactor
Sample reactor that panics the system when an exception is found. This
is useful both to capture a vmcore, or to fail-safe a critical system.

Link: https://lkml.kernel.org/r/729aae3aba95f35738b8f8180e626d747d1d9da2.1659052063.git.bristot@kernel.org

Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Gabriele Paoloni <gpaoloni@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-07-30 14:01:30 -04:00
Daniel Bristot de Oliveira
135b881ea8 rv/reactor: Add the printk reactor
A reactor that printks the reaction message.

Link: https://lkml.kernel.org/r/b65f18a7fd6dc6659a3008fd7b7392de3465d47b.1659052063.git.bristot@kernel.org

Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Gabriele Paoloni <gpaoloni@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-07-30 14:01:30 -04:00
Daniel Bristot de Oliveira
ccc319dcb4 rv/monitor: Add the wwnr monitor
Per task wakeup while not running (wwnr) monitor.

This model is broken, the reason is that a task can be running in the
processor without being set as RUNNABLE. Think about a task about to
sleep:

1:      set_current_state(TASK_UNINTERRUPTIBLE);
2:      schedule();

And then imagine an IRQ happening in between the lines one and two,
waking the task up. BOOM, the wakeup will happen while the task is
running.

Q: Why do we need this model, so?
A: To test the reactors.

Link: https://lkml.kernel.org/r/473c0fc39967250fdebcff8b620311c11dccad30.1659052063.git.bristot@kernel.org

Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Gabriele Paoloni <gpaoloni@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-07-30 14:01:30 -04:00
Daniel Bristot de Oliveira
10bde81c74 rv/monitor: Add the wip monitor
The wakeup in preemptive (wip) monitor verifies if the
wakeup events always take place with preemption disabled:

                     |
                     |
                     v
                   #==================#
                   H    preemptive    H <+
                   #==================#  |
                     |                   |
                     | preempt_disable   | preempt_enable
                     v                   |
    sched_waking   +------------------+  |
  +--------------- |                  |  |
  |                |  non_preemptive  |  |
  +--------------> |                  | -+
                   +------------------+

The wakeup event always takes place with preemption disabled because
of the scheduler synchronization. However, because the preempt_count
and its trace event are not atomic with regard to interrupts, some
inconsistencies might happen.

The documentation illustrates one of these cases.

Link: https://lkml.kernel.org/r/c98ca678df81115fddc04921b3c79720c836b18f.1659052063.git.bristot@kernel.org

Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Gabriele Paoloni <gpaoloni@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-07-30 14:01:30 -04:00
Daniel Bristot de Oliveira
8812d21219 rv/monitor: Add the wip monitor skeleton created by dot2k
THIS CODE IS NOT LINKED TO THE MAKEFILE.

This model does not compile because it lacks the instrumentation
part, which will be added next. In the typical case, there will be
only one patch, but it was split into two patches for educational
purposes.

This is the direct output this command line:
  $ dot2k -d tools/verification/models/wip.dot -t per_cpu

Link: https://lkml.kernel.org/r/5eb7a9118917e8a814c5e49853a72fc62be0a101.1659052063.git.bristot@kernel.org

Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Gabriele Paoloni <gpaoloni@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-07-30 14:01:29 -04:00
Daniel Bristot de Oliveira
ff0aaf6712 Documentation/rv: Add a basic documentation
Add the runtime-verification.rst document, explaining the basics of RV
and how to use the interface.

Link: https://lkml.kernel.org/r/4be7d1a88ab1e2eb0767521e1ab52a149a154bc4.1659052063.git.bristot@kernel.org

Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Gabriele Paoloni <gpaoloni@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-07-30 14:01:29 -04:00
Daniel Bristot de Oliveira
792575348f rv/include: Add deterministic automata monitor definition via C macros
In Linux terms, the runtime verification monitors are encapsulated
inside the "RV monitor" abstraction. The "RV monitor" includes a set
of instances of the monitor (per-cpu monitor, per-task monitor, and
so on), the helper functions that glue the monitor to the system
reference model, and the trace output as a reaction for event parsing
and exceptions, as depicted below:

Linux  +----- RV Monitor ----------------------------------+ Formal
 Realm |                                                   |  Realm
 +-------------------+     +----------------+     +-----------------+
 |   Linux kernel    |     |     Monitor    |     |     Reference   |
 |     Tracing       |  -> |   Instance(s)  | <-  |       Model     |
 | (instrumentation) |     | (verification) |     | (specification) |
 +-------------------+     +----------------+     +-----------------+
        |                          |                       |
        |                          V                       |
        |                     +----------+                 |
        |                     | Reaction |                 |
        |                     +--+--+--+-+                 |
        |                        |  |  |                   |
        |                        |  |  +-> trace output ?  |
        +------------------------|--|----------------------+
                                 |  +----> panic ?
                                 +-------> <user-specified>

Add the rv/da_monitor.h, enabling automatic code generation for the
*Monitor Instance(s)* using C macros, and code to support it.

The benefits of the usage of macro for monitor synthesis are 3-fold as it:

- Reduces the code duplication;
- Facilitates the bug fix/improvement;
- Avoids the case of developers changing the core of the monitor code
  to manipulate the model in a (let's say) non-standard way.

This initial implementation presents three different types of monitor
instances:

- DECLARE_DA_MON_GLOBAL(name, type)
- DECLARE_DA_MON_PER_CPU(name, type)
- DECLARE_DA_MON_PER_TASK(name, type)

The first declares the functions for a global deterministic automata monitor,
the second for monitors with per-cpu instances, and the third with per-task
instances.

Link: https://lkml.kernel.org/r/51b0bf425a281e226dfeba7401d2115d6091f84e.1659052063.git.bristot@kernel.org

Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Gabriele Paoloni <gpaoloni@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-07-30 14:01:28 -04:00
Daniel Bristot de Oliveira
04acadcb44 rv: Add runtime reactors interface
A runtime monitor can cause a reaction to the detection of an
exception on the model's execution. By default, the monitors have
tracing reactions, printing the monitor output via tracepoints.
But other reactions can be added (on-demand) via this interface.

The user interface resembles the kernel tracing interface and
presents these files:

"available_reactors"
  - Reading shows the available reactors, one per line.

   For example:
     # cat available_reactors
     nop
     panic
     printk

 "reacting_on"
   - It is an on/off general switch for reactors, disabling
   all reactions.

 "monitors/MONITOR/reactors"
   - List available reactors, with the select reaction for the given
   MONITOR inside []. The default one is the nop (no operation)
   reactor.
   - Writing the name of a reactor enables it to the given
   MONITOR.

   For example:
     # cat monitors/wip/reactors
     [nop]
     panic
     printk
     # echo panic > monitors/wip/reactors
     # cat monitors/wip/reactors
     nop
     [panic]
     printk

Link: https://lkml.kernel.org/r/1794eb994637457bdeaa6bad0b8263d2f7eece0c.1659052063.git.bristot@kernel.org

Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Gabriele Paoloni <gpaoloni@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-07-30 14:01:28 -04:00
Daniel Bristot de Oliveira
102227b970 rv: Add Runtime Verification (RV) interface
RV is a lightweight (yet rigorous) method that complements classical
exhaustive verification techniques (such as model checking and
theorem proving) with a more practical approach to complex systems.

RV works by analyzing the trace of the system's actual execution,
comparing it against a formal specification of the system behavior.
RV can give precise information on the runtime behavior of the
monitored system while enabling the reaction for unexpected
events, avoiding, for example, the propagation of a failure on
safety-critical systems.

The development of this interface roots in the development of the
paper:

De Oliveira, Daniel Bristot; Cucinotta, Tommaso; De Oliveira, Romulo
Silva. Efficient formal verification for the Linux kernel. In:
International Conference on Software Engineering and Formal Methods.
Springer, Cham, 2019. p. 315-332.

And:

De Oliveira, Daniel Bristot. Automata-based formal analysis
and verification of the real-time Linux kernel. PhD Thesis, 2020.

The RV interface resembles the tracing/ interface on purpose. The current
path for the RV interface is /sys/kernel/tracing/rv/.

It presents these files:

 "available_monitors"
   - List the available monitors, one per line.

   For example:
     # cat available_monitors
     wip
     wwnr

 "enabled_monitors"
   - Lists the enabled monitors, one per line;
   - Writing to it enables a given monitor;
   - Writing a monitor name with a '!' prefix disables it;
   - Truncating the file disables all enabled monitors.

   For example:
     # cat enabled_monitors
     # echo wip > enabled_monitors
     # echo wwnr >> enabled_monitors
     # cat enabled_monitors
     wip
     wwnr
     # echo '!wip' >> enabled_monitors
     # cat enabled_monitors
     wwnr
     # echo > enabled_monitors
     # cat enabled_monitors
     #

   Note that more than one monitor can be enabled concurrently.

 "monitoring_on"
   - It is an on/off general switcher for monitoring. Note
   that it does not disable enabled monitors or detach events,
   but stop the per-entity monitors of monitoring the events
   received from the system. It resembles the "tracing_on" switcher.

 "monitors/"
   Each monitor will have its one directory inside "monitors/". There
   the monitor specific files will be presented.
   The "monitors/" directory resembles the "events" directory on
   tracefs.

   For example:
     # cd monitors/wip/
     # ls
     desc  enable
     # cat desc
     wakeup in preemptive per-cpu testing monitor.
     # cat enable
     0

For further information, see the comments in the header of
kernel/trace/rv/rv.c from this patch.

Link: https://lkml.kernel.org/r/a4bfe038f50cb047bfb343ad0e12b0e646ab308b.1659052063.git.bristot@kernel.org

Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Gabriele Paoloni <gpaoloni@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-07-30 14:01:28 -04:00
Waiman Long
6eebd5fb20 locking/rwsem: Allow slowpath writer to ignore handoff bit if not set by first waiter
With commit d257cc8cb8 ("locking/rwsem: Make handoff bit handling more
consistent"), the writer that sets the handoff bit can be interrupted
out without clearing the bit if the wait queue isn't empty. This disables
reader and writer optimistic lock spinning and stealing.

Now if a non-first writer in the queue is somehow woken up or a new
waiter enters the slowpath, it can't acquire the lock.  This is not the
case before commit d257cc8cb8 as the writer that set the handoff bit
will clear it when exiting out via the out_nolock path. This is less
efficient as the busy rwsem stays in an unlock state for a longer time.

In some cases, this new behavior may cause lockups as shown in [1] and
[2].

This patch allows a non-first writer to ignore the handoff bit if it
is not originally set or initiated by the first waiter. This patch is
shown to be effective in fixing the lockup problem reported in [1].

[1] https://lore.kernel.org/lkml/20220617134325.GC30825@techsingularity.net/
[2] https://lore.kernel.org/lkml/3f02975c-1a9d-be20-32cf-f1d8e3dfafcc@oracle.com/

Fixes: d257cc8cb8 ("locking/rwsem: Make handoff bit handling more consistent")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: John Donnelly <john.p.donnelly@oracle.com>
Tested-by: Mel Gorman <mgorman@techsingularity.net>
Link: https://lore.kernel.org/r/20220622200419.778799-1-longman@redhat.com
2022-07-30 10:58:28 +02:00
Jakub Kicinski
5fc7c5887c Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Andrii Nakryiko says:

====================
 bpf-next 2022-07-29

We've added 22 non-merge commits during the last 4 day(s) which contain
a total of 27 files changed, 763 insertions(+), 120 deletions(-).

The main changes are:

1) Fixes to allow setting any source IP with bpf_skb_set_tunnel_key() helper,
   from Paul Chaignon.

2) Fix for bpf_xdp_pointer() helper when doing sanity checking, from Joanne Koong.

3) Fix for XDP frame length calculation, from Lorenzo Bianconi.

4) Libbpf BPF_KSYSCALL docs improvements and fixes to selftests to accommodate
   s390x quirks with socketcall(), from Ilya Leoshkevich.

5) Allow/denylist and CI configs additions to selftests/bpf to improve BPF CI,
   from Daniel Müller.

6) BPF trampoline + ftrace follow up fixes, from Song Liu and Xu Kuohai.

7) Fix allocation warnings in netdevsim, from Jakub Kicinski.

8) bpf_obj_get_opts() libbpf API allowing to provide file flags, from Joe Burton.

9) vsnprintf usage fix in bpf_snprintf_btf(), from Fedor Tokarev.

10) Various small fixes and clean ups, from Daniel Müller, Rongguang Wei,
    Jörn-Thorben Hinz, Yang Li.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (22 commits)
  bpf: Remove unneeded semicolon
  libbpf: Add bpf_obj_get_opts()
  netdevsim: Avoid allocation warnings triggered from user space
  bpf: Fix NULL pointer dereference when registering bpf trampoline
  bpf: Fix test_progs -j error with fentry/fexit tests
  selftests/bpf: Bump internal send_signal/send_signal_tracepoint timeout
  bpftool: Don't try to return value from void function in skeleton
  bpftool: Replace sizeof(arr)/sizeof(arr[0]) with ARRAY_SIZE macro
  bpf: btf: Fix vsnprintf return value check
  libbpf: Support PPC in arch_specific_syscall_pfx
  selftests/bpf: Adjust vmtest.sh to use local kernel configuration
  selftests/bpf: Copy over libbpf configs
  selftests/bpf: Sort configuration
  selftests/bpf: Attach to socketcall() in test_probe_user
  libbpf: Extend BPF_KSYSCALL documentation
  bpf, devmap: Compute proper xdp_frame len redirecting frames
  bpf: Fix bpf_xdp_pointer return pointer
  selftests/bpf: Don't assign outer source IP to host
  bpf: Set flow flag to allow any source IP in bpf_tunnel_key
  geneve: Use ip_tunnel_key flow flags in route lookups
  ...
====================

Link: https://lore.kernel.org/r/20220729230948.1313527-1-andrii@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-29 19:04:29 -07:00
Ben Dooks
787dbea11a profile: setup_profiling_timer() is moslty not implemented
The setup_profiling_timer() is mostly un-implemented by many
architectures.  In many places it isn't guarded by CONFIG_PROFILE which is
needed for it to be used.  Make it a weak symbol in kernel/profile.c and
remove the 'return -EINVAL' implementations from the kenrel.

There are a couple of architectures which do return 0 from the
setup_profiling_timer() function but they don't seem to do anything else
with it.  To keep the /proc compatibility for now, leave these for a
future update or removal.

On ARM, this fixes the following sparse warning:
arch/arm/kernel/smp.c:793:5: warning: symbol 'setup_profiling_timer' was not declared. Should it be static?

Link: https://lkml.kernel.org/r/20220721195509.418205-1-ben-linux@fluff.org
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-29 18:12:36 -07:00
Ben Dooks
591c32bddb kernel/hung_task: fix address space of proc_dohung_task_timeout_secs
The proc_dohung_task_timeout_secs() function is incorrectly marked
as having a __user buffer as argument 3. However this is not the
case and it is casing multiple sparse warnings. Fix the following
warnings by removing __user from the argument:

kernel/hung_task.c:237:52: warning: incorrect type in argument 3 (different address spaces)
kernel/hung_task.c:237:52:    expected void *
kernel/hung_task.c:237:52:    got void [noderef] __user *buffer
kernel/hung_task.c:287:35: warning: incorrect type in initializer (incompatible argument 3 (different address spaces))
kernel/hung_task.c:287:35:    expected int ( [usertype] *proc_handler )( ... )
kernel/hung_task.c:287:35:    got int ( * )( ... )
kernel/hung_task.c:295:35: warning: incorrect type in initializer (incompatible argument 3 (different address spaces))
kernel/hung_task.c:295:35:    expected int ( [usertype] *proc_handler )( ... )
kernel/hung_task.c:295:35:    got int ( * )( ... )

Link: https://lkml.kernel.org/r/20220714074744.189017-1-ben.dooks@sifive.com
Signed-off-by: Ben Dooks <ben.dooks@sifive.com>
Cc: <Conor.Dooley@microchip.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-29 18:12:35 -07:00
Yang Li
14250fa483 bpf: Remove unneeded semicolon
Eliminate the following coccicheck warning:
/kernel/bpf/trampoline.c:101:2-3: Unneeded semicolon

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220725222733.55613-1-yang.lee@linux.alibaba.com
2022-07-29 15:34:11 -07:00
Xu Kuohai
3b317abc71 bpf: Fix NULL pointer dereference when registering bpf trampoline
A panic was reported on arm64:

[   44.517109] audit: type=1334 audit(1658859870.268:59): prog-id=19 op=LOAD
[   44.622031] Unable to handle kernel NULL pointer dereference at
virtual address 0000000000000010
[   44.624321] Mem abort info:
[   44.625049]   ESR = 0x0000000096000004
[   44.625935]   EC = 0x25: DABT (current EL), IL = 32 bits
[   44.627182]   SET = 0, FnV = 0
[   44.627930]   EA = 0, S1PTW = 0
[   44.628684]   FSC = 0x04: level 0 translation fault
[   44.629788] Data abort info:
[   44.630474]   ISV = 0, ISS = 0x00000004
[   44.631362]   CM = 0, WnR = 0
[   44.632041] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000100ab5000
[   44.633494] [0000000000000010] pgd=0000000000000000, p4d=0000000000000000
[   44.635202] Internal error: Oops: 96000004 [#1] SMP
[   44.636452] Modules linked in: xfs crct10dif_ce ghash_ce virtio_blk
virtio_console virtio_mmio qemu_fw_cfg
[   44.638713] CPU: 2 PID: 1 Comm: systemd Not tainted 5.19.0-rc7 #1
[   44.640164] Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
[   44.641799] pstate: 00400005 (nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[   44.643404] pc : ftrace_set_filter_ip+0x24/0xa0
[   44.644659] lr : bpf_trampoline_update.constprop.0+0x428/0x4a0
[   44.646118] sp : ffff80000803b9f0
[   44.646950] x29: ffff80000803b9f0 x28: ffff0b5d80364400 x27: ffff80000803bb48
[   44.648721] x26: ffff8000085ad000 x25: ffff0b5d809d2400 x24: 0000000000000000
[   44.650493] x23: 00000000ffffffed x22: ffff0b5dd7ea0900 x21: 0000000000000000
[   44.652279] x20: 0000000000000000 x19: 0000000000000000 x18: ffffffffffffffff
[   44.654067] x17: 0000000000000000 x16: 0000000000000000 x15: ffffffffffffffff
[   44.655787] x14: ffff0b5d809d2498 x13: ffff0b5d809d2432 x12: 0000000005f5e100
[   44.657535] x11: abcc77118461cefd x10: 000000000000005f x9 : ffffa7219cb5b190
[   44.659254] x8 : ffffa7219c8e0000 x7 : 0000000000000000 x6 : ffffa7219db075e0
[   44.661066] x5 : ffffa7219d3130e0 x4 : ffffa7219cab9da0 x3 : 0000000000000000
[   44.662837] x2 : 0000000000000000 x1 : ffffa7219cb7a5c0 x0 : 0000000000000000
[   44.664675] Call trace:
[   44.665274]  ftrace_set_filter_ip+0x24/0xa0
[   44.666327]  bpf_trampoline_update.constprop.0+0x428/0x4a0
[   44.667696]  __bpf_trampoline_link_prog+0xcc/0x1c0
[   44.668834]  bpf_trampoline_link_prog+0x40/0x64
[   44.669919]  bpf_tracing_prog_attach+0x120/0x490
[   44.671011]  link_create+0xe0/0x2b0
[   44.671869]  __sys_bpf+0x484/0xd30
[   44.672706]  __arm64_sys_bpf+0x30/0x40
[   44.673678]  invoke_syscall+0x78/0x100
[   44.674623]  el0_svc_common.constprop.0+0x4c/0xf4
[   44.675783]  do_el0_svc+0x38/0x4c
[   44.676624]  el0_svc+0x34/0x100
[   44.677429]  el0t_64_sync_handler+0x11c/0x150
[   44.678532]  el0t_64_sync+0x190/0x194
[   44.679439] Code: 2a0203f4 f90013f5 2a0303f5 f9001fe1 (f9400800)
[   44.680959] ---[ end trace 0000000000000000 ]---
[   44.682111] Kernel panic - not syncing: Oops: Fatal exception
[   44.683488] SMP: stopping secondary CPUs
[   44.684551] Kernel Offset: 0x2721948e0000 from 0xffff800008000000
[   44.686095] PHYS_OFFSET: 0xfffff4a380000000
[   44.687144] CPU features: 0x010,00022811,19001080
[   44.688308] Memory Limit: none
[   44.689082] ---[ end Kernel panic - not syncing: Oops: Fatal exception ]---

It's caused by a NULL tr->fops passed to ftrace_set_filter_ip(). tr->fops
is initialized to NULL and is assigned to an allocated memory address if
CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS is enabled. Since there is no
direct call on arm64 yet, the config can't be enabled.

To fix it, call ftrace_set_filter_ip() only if tr->fops is not NULL.

Fixes: 00963a2e75 ("bpf: Support bpf_trampoline on functions with IPMODIFY (e.g. livepatch)")
Reported-by: Bruno Goncalves <bgoncalv@redhat.com>
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Bruno Goncalves <bgoncalv@redhat.com>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20220728114048.3540461-1-xukuohai@huaweicloud.com
2022-07-29 14:42:09 -07:00
Song Liu
dc81f8d1e8 bpf: Fix test_progs -j error with fentry/fexit tests
When multiple threads are attaching/detaching fentry/fexit programs to
the same trampoline, we may call register_fentry on the same trampoline
twice: register_fentry(), unregister_fentry(), then register_fentry again.
This causes ftrace_set_filter_ip() for the same ip on tr->fops twice,
which leaves duplicated ip in tr->fops. The extra ip is not cleaned up
properly on unregister and thus causes failures with further register in
register_ftrace_direct_multi():

register_ftrace_direct_multi()
{
        ...
        for (i = 0; i < size; i++) {
                hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
                        if (ftrace_find_rec_direct(entry->ip))
                                goto out_unlock;
                }
        }
        ...
}

This can be triggered with parallel fentry/fexit tests with test_progs:

  ./test_progs -t fentry,fexit -j

Fix this by resetting tr->fops in ftrace_set_filter_ip(), so that there
will never be duplicated entries in tr->fops.

Fixes: 00963a2e75 ("bpf: Support bpf_trampoline on functions with IPMODIFY (e.g. livepatch)")
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220729194106.1207472-1-song@kernel.org
2022-07-29 14:20:29 -07:00
Linus Torvalds
4b20426d04 wq fixes for v5.19-rc8
Just one commit to suppress a spurious warning added during the 5.19 cycle.
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Merge tag 'wq-for-5.19-rc8-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

Pull workqueue fix from Tejun Heo:
 "Just one commit to suppress a spurious warning added during the 5.19
  cycle"

* tag 'wq-for-5.19-rc8-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: Avoid a false warning in unbind_workers()
2022-07-29 11:20:40 -07:00
Lai Jiangshan
46a4d679ef workqueue: Avoid a false warning in unbind_workers()
Doing set_cpus_allowed_ptr() with wq_unbound_cpumask can be possible
fails and trigger the false warning.

Use cpu_possible_mask instead when wq_unbound_cpumask has no active CPUs.

It is very easy to trigger the warning:
  Set wq_unbound_cpumask to a small set of CPUs.
  Offline all the CPUs of wq_unbound_cpumask.
  Offline an extra CPU and trigger the warning.

Fixes: 10a5a651e3 ("workqueue: Restrict kworker in the offline CPU pool running on housekeeping CPUs")
Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-07-29 07:49:02 -10:00
Rafael J. Wysocki
aa727b7b4b Merge branches 'pm-devfreq', 'pm-qos', 'pm-tools' and 'pm-docs'
Merge devfreq changes, PM QoS change, and power management tools and
documentation changes for v5.20-rc1:

 - Add new devfreq driver for Mediatek CCI (Cache Coherent
   Interconnect) (Johnson Wang).

 - Convert the Samsung Exynos SoC Bus bindings to DT schema of
   exynos-bus.c (Krzysztof Kozlowski).

 - Address kernel-doc warnings by adding the description for unused
   fucntion parameters in devfreq core (Mauro Carvalho Chehab).

 - Use NULL to pass a null pointer rather than zero according to the
   function propotype in imx-bus.c (Colin Ian King).

 - Print error message instead of error interger value in
   tegra30-devfreq.c (Dmitry Osipenko).

 - Add checks to prevent setting negative frequency QoS limits for
   CPUs (Shivnandan Kumar).

 - Update the pm-graph suite of utilities to the latest revision 5.9
   including multiple improvements (Todd Brandt).

 - Drop pme_interrupt reference from the PCI power management
   documentation (Mario Limonciello).

* pm-devfreq:
  PM / devfreq: tegra30: Add error message for devm_devfreq_add_device()
  PM / devfreq: imx-bus: use NULL to pass a null pointer rather than zero
  PM / devfreq: shut up kernel-doc warnings
  dt-bindings: interconnect: samsung,exynos-bus: convert to dtschema
  PM / devfreq: mediatek: Introduce MediaTek CCI devfreq driver
  dt-bindings: interconnect: Add MediaTek CCI dt-bindings

* pm-qos:
  PM: QoS: Add check to make sure CPU freq is non-negative

* pm-tools:
  pm-graph v5.9

* pm-docs:
  Documentation: PM: Drop pme_interrupt reference
2022-07-29 19:46:00 +02:00
Rafael J. Wysocki
954a83fc60 Merge branches 'pm-core', 'pm-sleep', 'powercap', 'pm-domains' and 'pm-em'
Merge core device power management changes for v5.20-rc1:

 - Extend support for wakeirq to callback wrappers used during system
   suspend and resume (Ulf Hansson).

 - Defer waiting for device probe before loading a hibernation image
   till the first actual device access to avoid possible deadlocks
   reported by syzbot (Tetsuo Handa).

 - Unify device_init_wakeup() for PM_SLEEP and !PM_SLEEP (Bjorn
   Helgaas).

 - Add Raptor Lake-P to the list of processors supported by the Intel
   RAPL driver (George D Sworo).

 - Add Alder Lake-N and Raptor Lake-P to the list of processors for
   which Power Limit4 is supported in the Intel RAPL driver (Sumeet
   Pawnikar).

 - Make pm_genpd_remove() check genpd_debugfs_dir against NULL before
   attempting to remove it (Hsin-Yi Wang).

 - Change the Energy Model code to represent power in micro-Watts and
   adjust its users accordingly (Lukasz Luba).

* pm-core:
  PM: runtime: Extend support for wakeirq for force_suspend|resume

* pm-sleep:
  PM: hibernate: defer device probing when resuming from hibernation
  PM: wakeup: Unify device_init_wakeup() for PM_SLEEP and !PM_SLEEP

* powercap:
  powercap: RAPL: Add Power Limit4 support for Alder Lake-N and Raptor Lake-P
  powercap: intel_rapl: Add support for RAPTORLAKE_P

* pm-domains:
  PM: domains: Ensure genpd_debugfs_dir exists before remove

* pm-em:
  cpufreq: scmi: Support the power scale in micro-Watts in SCMI v3.1
  firmware: arm_scmi: Get detailed power scale from perf
  Documentation: EM: Switch to micro-Watts scale
  PM: EM: convert power field to micro-Watts precision and align drivers
2022-07-29 19:33:13 +02:00
Fedor Tokarev
58250ae350 bpf: btf: Fix vsnprintf return value check
vsnprintf returns the number of characters which would have been written if
enough space had been available, excluding the terminating null byte. Thus,
the return value of 'len_left' means that the last character has been
dropped.

Signed-off-by: Fedor Tokarev <ftokarev@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/bpf/20220711211317.GA1143610@laptop
2022-07-29 09:57:14 -07:00
Jakub Kicinski
272ac32f56 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
No conflicts.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-28 18:21:16 -07:00
Waiman Long
265792d0de cgroup: Skip subtree root in cgroup_update_dfl_csses()
The cgroup_update_dfl_csses() function updates css associations when a
cgroup's subtree_control file is modified. Any changes made to a cgroup's
subtree_control file, however, will only affect its descendants but not
the cgroup itself. So there is no point in migrating csses associated
with that cgroup. We can skip them instead.

Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-07-28 07:26:30 -10:00
Linus Torvalds
e64ab2dbd8 watch_queue: Fix missing locking in add_watch_to_object()
If a watch is being added to a queue, it needs to guard against
interference from addition of a new watch, manual removal of a watch and
removal of a watch due to some other queue being destroyed.

KEYCTL_WATCH_KEY guards against this for the same {key,queue} pair by
holding the key->sem writelocked and by holding refs on both the key and
the queue - but that doesn't prevent interaction from other {key,queue}
pairs.

While add_watch_to_object() does take the spinlock on the event queue,
it doesn't take the lock on the source's watch list.  The assumption was
that the caller would prevent that (say by taking key->sem) - but that
doesn't prevent interference from the destruction of another queue.

Fix this by locking the watcher list in add_watch_to_object().

Fixes: c73be61ced ("pipe: Add general notification queue support")
Reported-by: syzbot+03d7b43290037d1f87ca@syzkaller.appspotmail.com
Signed-off-by: David Howells <dhowells@redhat.com>
cc: keyrings@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-07-28 10:06:49 -07:00
David Howells
e0339f036e watch_queue: Fix missing rcu annotation
Since __post_watch_notification() walks wlist->watchers with only the
RCU read lock held, we need to use RCU methods to add to the list (we
already use RCU methods to remove from the list).

Fix add_watch_to_object() to use hlist_add_head_rcu() instead of
hlist_add_head() for that list.

Fixes: c73be61ced ("pipe: Add general notification queue support")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-07-28 10:06:49 -07:00
Tianyu Lan
5c850d3188 swiotlb: fix passing local variable to debugfs_create_ulong()
Debugfs node will be run-timely checked and so local variable
should be not passed to debugfs_create_ulong(). Fix it via
debugfs_create_file() to create io_tlb_used node and calculate
used io tlb number with fops_io_tlb_used attribute.

Fixes: 20347fca71 ("swiotlb: split up the global swiotlb lock")
Signed-off-by: Tianyu Lan <tiala@microsoft.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2022-07-28 07:23:30 -07:00
Logan Gunthorpe
8419702489 dma-mapping: reformat comment to suppress htmldoc warning
make html doc reports a cryptic warning with the commit named below:

  kernel/dma/mapping.c:258: WARNING: Option list ends without a blank
                                     line; unexpected unindent.

Seems the parser is a bit fussy about the tabbing and having a single
space tab causes the warning. To suppress the warning add another
tab to the list and reindent everything.

Fixes: 7c2645a2a3 ("dma-mapping: allow EREMOTEIO return code for P2PDMA transfers")
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2022-07-28 07:21:33 -07:00
Thomas Gleixner
779fda86bd irqchip/genirq updates for 5.20:
* Core code update:
 
   - Non-SMP IRQ affinity fixes, allowing UP kernel to behave similarly
     to SMP ones for the purpose of interrupt affinity
 
   - Let irq_set_chip_handler_name_locked() take a const struct irq_chip *
 
   - Tidy-up the NOMAP irqdomain API variant
 
   - Teach action_show() to use for_each_action_of_desc()
 
   - Make irq_chip_request_resources_parent() allow the parent callback
     to be optional
 
   - Remove dynamic allocations from populate_parent_alloc_arg()
 
 * New drivers:
 
   - Merge the long awaited IRQ support for the LoongArch architecture,
     with the provisional ACPICA update (to be reverted once the official
     support lands)
 
   - New Renesas RZ/G2L IRQC driver, equipped with its companion GPIO
     driver
 
 * Driver updates
 
   - Optimise the hot path operations for the SiFive PLIC, trading the
     locking for per-CPU priority masking masking operations which are
     apparently faster
 
   - Work around broken PLIC implementations that deal pretty badly with
     edge-triggered interrupts. Flag two implementations as affected.
 
   - Simplify the irq-stm32-exti driver, particularly the table that
     remaps the interrupts from exti to the GIC, reducing the memory usage
 
   - Convert the ocelot irq_chip to being immutable
 
   - Check ioremap() return value in the MIPS GIC driver
 
   - Move MMP driver init function declarations into the common .h
 
   - The obligatory typo fixes
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Merge tag 'irqchip-5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core

Pull irqchip/genirq updates from Marc Zyngier:

 * Core code update:

  - Non-SMP IRQ affinity fixes, allowing UP kernel to behave similarly
    to SMP ones for the purpose of interrupt affinity

  - Let irq_set_chip_handler_name_locked() take a const struct irq_chip *

  - Tidy-up the NOMAP irqdomain API variant

  - Teach action_show() to use for_each_action_of_desc()

  - Make irq_chip_request_resources_parent() allow the parent callback
    to be optional

  - Remove dynamic allocations from populate_parent_alloc_arg()

 * New drivers:

  - Merge the long awaited IRQ support for the LoongArch architecture,
    with the provisional ACPICA update (to be reverted once the official
    support lands)

  - New Renesas RZ/G2L IRQC driver, equipped with its companion GPIO
    driver

 * Driver updates

  - Optimise the hot path operations for the SiFive PLIC, trading the
    locking for per-CPU priority masking masking operations which are
    apparently faster

  - Work around broken PLIC implementations that deal pretty badly with
    edge-triggered interrupts. Flag two implementations as affected.

  - Simplify the irq-stm32-exti driver, particularly the table that
    remaps the interrupts from exti to the GIC, reducing the memory usage

  - Convert the ocelot irq_chip to being immutable

  - Check ioremap() return value in the MIPS GIC driver

  - Move MMP driver init function declarations into the common .h

  - The obligatory typo fixes

Link: https://lore.kernel.org/all/20220727192356.1860546-1-maz@kernel.org
2022-07-28 12:36:35 +02:00
Tejun Heo
c808f46323 cgroup: remove "no" prefixed mount options
30312730bd ("cgroup: Add "no" prefixed mount options") added "no" prefixed
mount options to allow turning them off and 6a010a49b6 ("cgroup: Make
!percpu threadgroup_rwsem operations optional") added one more "no" prefixed
mount option. However, Michal pointed out that the "no" prefixed options
aren't necessary in allowing mount options to be turned off:

  # grep group /proc/mounts
  cgroup2 /sys/fs/cgroup cgroup2 rw,nosuid,nodev,relatime,nsdelegate,memory_recursiveprot 0 0
  # mount -o remount,nsdelegate,memory_recursiveprot none /sys/fs/cgroup
  # grep cgroup /proc/mounts
  cgroup2 /sys/fs/cgroup cgroup2 rw,relatime,nsdelegate,memory_recursiveprot 0 0

Note that this is different from the remount behavior when the mount(1) is
invoked without the device argument - "none":

 # grep cgroup /proc/mounts
 cgroup2 /sys/fs/cgroup cgroup2 rw,nosuid,nodev,noexec,relatime,nsdelegate,memory_recursiveprot 0 0
 # mount -o remount,nsdelegate,memory_recursiveprot /sys/fs/cgroup
 # grep cgroup /proc/mounts
 cgroup2 /sys/fs/cgroup cgroup2 rw,nosuid,nodev,noexec,relatime,nsdelegate,memory_recursiveprot 0 0

While a bit confusing, given that there is a way to turn off the options,
there's no reason to have the explicit "no" prefixed options. Let's remove
them.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-07-27 07:54:55 -10:00
Lukas Bulwahn
871808fd69 x86/configs: Update configs in x86_debug.config
Commit

  4675ff05de ("kmemcheck: rip it out")

removed kmemcheck and its corresponding build config KMEMCHECK.

Commit

  0f620cefd7 ("objtool: Rename "VMLINUX_VALIDATION" -> "NOINSTR_VALIDATION"")

renamed the debug config option.

Adjust x86_debug.config to those changes in debug configs.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220722121815.27535-1-lukas.bulwahn@gmail.com
2022-07-27 18:09:11 +02:00
Laurent Dufour
7c56a8733d watchdog: export lockup_detector_reconfigure
In some circumstances it may be interesting to reconfigure the watchdog
from inside the kernel.

On PowerPC, this may helpful before and after a LPAR migration (LPM) is
initiated, because it implies some latencies, watchdog, and especially NMI
watchdog is expected to be triggered during this operation. Reconfiguring
the watchdog with a factor, would prevent it to happen too frequently
during LPM.

Rename lockup_detector_reconfigure() as __lockup_detector_reconfigure() and
create a new function lockup_detector_reconfigure() calling
__lockup_detector_reconfigure() under the protection of watchdog_mutex.

Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
[mpe: Squash in build fix from Laurent, reported by Sachin]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220713154729.80789-3-ldufour@linux.ibm.com
2022-07-27 21:35:32 +10:00
Shivnandan Kumar
8d36694245 PM: QoS: Add check to make sure CPU freq is non-negative
CPU frequency should never be negative.

If some client driver calls freq_qos_update_request with a
negative value which will be very high in absolute terms,
then frequency QoS sets max CPU freq at fmax as it considers
it's absolute value but it will add plist node with negative
priority.

plist node has priority from INT_MIN (highest) to INT_MAX(lowest).
Once priority is set as negative, another client will not be able
to reduce CPU frequency.

Adding check to make sure CPU freq is non-negative will fix
this problem.

Signed-off-by: Shivnandan Kumar <quic_kshivnan@quicinc.com>
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-07-26 20:48:33 +02:00
Tetsuo Handa
8386c414e2 PM: hibernate: defer device probing when resuming from hibernation
syzbot is reporting hung task at misc_open() [1], for there is a race
window of AB-BA deadlock which involves probe_count variable. Currently
wait_for_device_probe() from snapshot_open() from misc_open() can sleep
forever with misc_mtx held if probe_count cannot become 0.

When a device is probed by hub_event() work function, probe_count is
incremented before the probe function starts, and probe_count is
decremented after the probe function completed.

There are three cases that can prevent probe_count from dropping to 0.

  (a) A device being probed stopped responding (i.e. broken/malicious
      hardware).

  (b) A process emulating a USB device using /dev/raw-gadget interface
      stopped responding for some reason.

  (c) New device probe requests keeps coming in before existing device
      probe requests complete.

The phenomenon syzbot is reporting is (b). A process which is holding
system_transition_mutex and misc_mtx is waiting for probe_count to become
0 inside wait_for_device_probe(), but the probe function which is called
 from hub_event() work function is waiting for the processes which are
blocked at mutex_lock(&misc_mtx) to respond via /dev/raw-gadget interface.

This patch mitigates (b) by deferring wait_for_device_probe() from
snapshot_open() to snapshot_write() and snapshot_ioctl(). Please note that
the possibility of (b) remains as long as any thread which is emulating a
USB device via /dev/raw-gadget interface can be blocked by uninterruptible
blocking operations (e.g. mutex_lock()).

Please also note that (a) and (c) are not addressed. Regarding (c), we
should change the code to wait for only one device which contains the
image for resuming from hibernation. I don't know how to address (a), for
use of timeout for wait_for_device_probe() might result in loss of user
data in the image. Maybe we should require the userland to wait for the
image device before opening /dev/snapshot interface.

Link: https://syzkaller.appspot.com/bug?extid=358c9ab4c93da7b7238c [1]
Reported-by: syzbot <syzbot+358c9ab4c93da7b7238c@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Tested-by: syzbot <syzbot+358c9ab4c93da7b7238c@syzkaller.appspotmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-07-26 20:39:01 +02:00
Lorenzo Bianconi
bd82ea52f0 bpf, devmap: Compute proper xdp_frame len redirecting frames
Even if it is currently forbidden to XDP_REDIRECT a multi-frag xdp_frame into
a devmap, compute proper xdp_frame length in __xdp_enqueue and is_valid_dst
routines running xdp_get_frame_len().

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/894d99c01139e921bdb6868158ff8e67f661c072.1658596075.git.lorenzo@kernel.org
2022-07-26 16:26:19 +02:00
Logan Gunthorpe
159bf19270 dma-mapping: add flags to dma_map_ops to indicate PCI P2PDMA support
Add a flags member to the dma_map_ops structure with one flag to
indicate support for PCI P2PDMA.

Also, add a helper to check if a device supports PCI P2PDMA.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2022-07-26 07:27:48 -04:00
Logan Gunthorpe
f02ad36d4f dma-direct: support PCI P2PDMA pages in dma-direct map_sg
Add PCI P2PDMA support for dma_direct_map_sg() so that it can map
PCI P2PDMA pages directly without a hack in the callers. This allows
for heterogeneous SGLs that contain both P2PDMA and regular pages.

A P2PDMA page may have three possible outcomes when being mapped:
  1) If the data path between the two devices doesn't go through the
     root port, then it should be mapped with a PCI bus address
  2) If the data path goes through the host bridge, it should be mapped
     normally, as though it were a CPU physical address
  3) It is not possible for the two devices to communicate and thus
     the mapping operation should fail (and it will return -EREMOTEIO).

SGL segments that contain PCI bus addresses are marked with
sg_dma_mark_pci_p2pdma() and are ignored when unmapped.

P2PDMA mappings are also failed if swiotlb needs to be used on the
mapping.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2022-07-26 07:27:47 -04:00
Logan Gunthorpe
7c2645a2a3 dma-mapping: allow EREMOTEIO return code for P2PDMA transfers
Add EREMOTEIO error return to dma_map_sgtable() which will be used
by .map_sg() implementations that detect P2PDMA pages that the
underlying DMA device cannot access.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2022-07-26 07:27:47 -04:00
Marc Zyngier
2bd1753e8c Merge branch irq/misc-5.20 into irq/irqchip-next
* irq/misc-5.20:
  : .
  : Misc IRQ changes for 5.20:
  :
  : - Let irq_set_chip_handler_name_locked() take a const struct irq_chip *
  :
  : - Convert the ocelot irq_chip to being immutable (depends on the above)
  :
  : - Tidy-up the NOMAP irqdomain API variant
  :
  : - Teach action_show() to use for_each_action_of_desc()
  :
  : - Check ioremap() return value in the MIPS GIC driver
  :
  : - Move MMP driver init function declarations into the common .h
  :
  : - The obligatory typo fixes
  : .
  irqchip/mmp: Declare init functions in common header file
  irqchip/mips-gic: Check the return value of ioremap() in gic_of_init()
  genirq: Use for_each_action_of_desc in actions_show()
  irqdomain: Use hwirq_max instead of revmap_size for NOMAP domains
  irqdomain: Report irq number for NOMAP domains
  irqchip/gic-v3: Fix comment typo
  pinctrl: ocelot: Make irq_chip immutable
  genirq: Allow irq_set_chip_handler_name_locked() to take a const irq_chip

Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-07-25 09:45:34 +01:00
Jens Axboe
ed29b0b4fd io_uring: move to separate directory
In preparation for splitting io_uring up a bit, move it into its own
top level directory. It didn't really belong in fs/ anyway, as it's
not a file system only API.

This adds io_uring/ and moves the core files in there, and updates the
MAINTAINERS file for the new location.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:10 -06:00
Linyu Yuan
95c104c378 tracing: Auto generate event name when creating a group of events
Currently when creating a specific group of trace events,
take kprobe event as example, the user must use the following format:
p:GRP/EVENT [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS],
which means user must enter EVENT name, one example is:

  echo 'p:usb_gadget/config_usb_cfg_link config_usb_cfg_link $arg1' >> kprobe_events

It is not simple if there are too many entries because the event name is
the same as symbol name.

This change allows user to specify no EVENT name, format changed as:

   p:GRP/ [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]

It will generate event name automatically and one example is:

  echo 'p:usb_gadget/ config_usb_cfg_link $arg1' >> kprobe_events.

Link: https://lore.kernel.org/all/1656296348-16111-4-git-send-email-quic_linyyuan@quicinc.com/

Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-07-24 19:11:17 -04:00
Linyu Yuan
f360ea5641 tracing: eprobe: Remove duplicate is_good_name() operation
traceprobe_parse_event_name() already validate SYSTEM and EVENT name,
there is no need to call is_good_name() after it.

Link: https://lore.kernel.org/all/1656296348-16111-3-git-send-email-quic_linyyuan@quicinc.com/

Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-07-24 19:11:17 -04:00
Linyu Yuan
b774926c73 tracing: eprobe: Add missing log index
Add trace_probe_log_set_index(1) to allow report correct error
if user input wrong SYSTEM.EVENT format.

Link: https://lore.kernel.org/all/1656296348-16111-2-git-send-email-quic_linyyuan@quicinc.com/

Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-07-24 19:11:17 -04:00
Linus Torvalds
c2602a7ce0 A single fix to correct a wrong BUG_ON() condition for deboosted tasks.
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Merge tag 'sched_urgent_for_v5.19_rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fix from Borislav Petkov:
 "A single fix to correct a wrong BUG_ON() condition for deboosted
  tasks"

* tag 'sched_urgent_for_v5.19_rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/deadline: Fix BUG_ON condition for deboosted tasks
2022-07-24 09:50:53 -07:00
Tejun Heo
6a010a49b6 cgroup: Make !percpu threadgroup_rwsem operations optional
3942a9bd7b ("locking, rcu, cgroup: Avoid synchronize_sched() in
__cgroup_procs_write()") disabled percpu operations on threadgroup_rwsem
because the impiled synchronize_rcu() on write locking was pushing up the
latencies too much for android which constantly moves processes between
cgroups.

This makes the hotter paths - fork and exit - slower as they're always
forced into the slow path. There is no reason to force this on everyone
especially given that more common static usage pattern can now completely
avoid write-locking the rwsem. Write-locking is elided when turning on and
off controllers on empty sub-trees and CLONE_INTO_CGROUP enables seeding a
cgroup without grabbing the rwsem.

Restore the default percpu operations and introduce the mount option
"favordynmods" and config option CGROUP_FAVOR_DYNMODS for users who need
lower latencies for the dynamic operations.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Michal Koutn� <mkoutny@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Dmitry Shmidt <dimitrysh@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
2022-07-23 04:29:02 -10:00
Tejun Heo
30312730bd cgroup: Add "no" prefixed mount options
We allow modifying these mount options via remount. Let's add "no" prefixed
variants so that they can be turned off too.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
2022-07-22 19:12:52 -10:00
Tejun Heo
671c11f061 cgroup: Elide write-locking threadgroup_rwsem when updating csses on an empty subtree
cgroup_update_dfl_csses() write-lock the threadgroup_rwsem as updating the
csses can trigger process migrations. However, if the subtree doesn't
contain any tasks, there aren't gonna be any cgroup migrations. This
condition can be trivially detected by testing whether
mgctx.preloaded_src_csets is empty. Elide write-locking threadgroup_rwsem if
the subtree is empty.

After this optimization, the usage pattern of creating a cgroup, enabling
the necessary controllers, and then seeding it with CLONE_INTO_CGROUP and
then removing the cgroup after it becomes empty doesn't need to write-lock
threadgroup_rwsem at all.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
2022-07-22 19:12:37 -10:00
Jakub Kicinski
b3fce974d4 Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
bpf-next 2022-07-22

We've added 73 non-merge commits during the last 12 day(s) which contain
a total of 88 files changed, 3458 insertions(+), 860 deletions(-).

The main changes are:

1) Implement BPF trampoline for arm64 JIT, from Xu Kuohai.

2) Add ksyscall/kretsyscall section support to libbpf to simplify tracing kernel
   syscalls through kprobe mechanism, from Andrii Nakryiko.

3) Allow for livepatch (KLP) and BPF trampolines to attach to the same kernel
   function, from Song Liu & Jiri Olsa.

4) Add new kfunc infrastructure for netfilter's CT e.g. to insert and change
   entries, from Kumar Kartikeya Dwivedi & Lorenzo Bianconi.

5) Add a ksym BPF iterator to allow for more flexible and efficient interactions
   with kernel symbols, from Alan Maguire.

6) Bug fixes in libbpf e.g. for uprobe binary path resolution, from Dan Carpenter.

7) Fix BPF subprog function names in stack traces, from Alexei Starovoitov.

8) libbpf support for writing custom perf event readers, from Jon Doron.

9) Switch to use SPDX tag for BPF helper man page, from Alejandro Colomar.

10) Fix xsk send-only sockets when in busy poll mode, from Maciej Fijalkowski.

11) Reparent BPF maps and their charging on memcg offlining, from Roman Gushchin.

12) Multiple follow-up fixes around BPF lsm cgroup infra, from Stanislav Fomichev.

13) Use bootstrap version of bpftool where possible to speed up builds, from Pu Lehui.

14) Cleanup BPF verifier's check_func_arg() handling, from Joanne Koong.

15) Make non-prealloced BPF map allocations low priority to play better with
    memcg limits, from Yafang Shao.

16) Fix BPF test runner to reject zero-length data for skbs, from Zhengchao Shao.

17) Various smaller cleanups and improvements all over the place.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (73 commits)
  bpf: Simplify bpf_prog_pack_[size|mask]
  bpf: Support bpf_trampoline on functions with IPMODIFY (e.g. livepatch)
  bpf, x64: Allow to use caller address from stack
  ftrace: Allow IPMODIFY and DIRECT ops on the same function
  ftrace: Add modify_ftrace_direct_multi_nolock
  bpf/selftests: Fix couldn't retrieve pinned program in xdp veth test
  bpf: Fix build error in case of !CONFIG_DEBUG_INFO_BTF
  selftests/bpf: Fix test_verifier failed test in unprivileged mode
  selftests/bpf: Add negative tests for new nf_conntrack kfuncs
  selftests/bpf: Add tests for new nf_conntrack kfuncs
  selftests/bpf: Add verifier tests for trusted kfunc args
  net: netfilter: Add kfuncs to set and change CT status
  net: netfilter: Add kfuncs to set and change CT timeout
  net: netfilter: Add kfuncs to allocate and insert CT
  net: netfilter: Deduplicate code in bpf_{xdp,skb}_ct_lookup
  bpf: Add documentation for kfuncs
  bpf: Add support for forcing kfunc args to be trusted
  bpf: Switch to new kfunc flags infrastructure
  tools/resolve_btfids: Add support for 8-byte BTF sets
  bpf: Introduce 8-byte BTF set
  ...
====================

Link: https://lore.kernel.org/r/20220722221218.29943-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-22 16:55:44 -07:00
Song Liu
ea2babac63 bpf: Simplify bpf_prog_pack_[size|mask]
Simplify the logic that selects bpf_prog_pack_size, and always use
(PMD_SIZE * num_possible_nodes()). This is a good tradeoff, as most of
the performance benefit observed is from less direct map fragmentation [0].

Also, module_alloc(4MB) may not allocate 4MB aligned memory. Therefore,
we cannot use (ptr & bpf_prog_pack_mask) to find the correct address of
bpf_prog_pack. Fix this by checking the header address falls in the range
of pack->ptr and (pack->ptr + bpf_prog_pack_size).

  [0] https://lore.kernel.org/bpf/20220707223546.4124919-1-song@kernel.org/

Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20220713204950.3015201-1-song@kernel.org
2022-07-22 22:08:27 +02:00
Song Liu
00963a2e75 bpf: Support bpf_trampoline on functions with IPMODIFY (e.g. livepatch)
When tracing a function with IPMODIFY ftrace_ops (livepatch), the bpf
trampoline must follow the instruction pointer saved on stack. This needs
extra handling for bpf trampolines with BPF_TRAMP_F_CALL_ORIG flag.

Implement bpf_tramp_ftrace_ops_func and use it for the ftrace_ops used
by BPF trampoline. This enables tracing functions with livepatch.

This also requires moving bpf trampoline to *_ftrace_direct_mult APIs.

Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/all/20220602193706.2607681-2-song@kernel.org/
Link: https://lore.kernel.org/bpf/20220720002126.803253-5-song@kernel.org
2022-07-22 22:04:37 +02:00
Song Liu
53cd885bc5 ftrace: Allow IPMODIFY and DIRECT ops on the same function
IPMODIFY (livepatch) and DIRECT (bpf trampoline) ops are both important
users of ftrace. It is necessary to allow them work on the same function
at the same time.

First, DIRECT ops no longer specify IPMODIFY flag. Instead, DIRECT flag is
handled together with IPMODIFY flag in __ftrace_hash_update_ipmodify().

Then, a callback function, ops_func, is added to ftrace_ops. This is used
by ftrace core code to understand whether the DIRECT ops can share with an
IPMODIFY ops. To share with IPMODIFY ops, the DIRECT ops need to implement
the callback function and adjust the direct trampoline accordingly.

If DIRECT ops is attached before the IPMODIFY ops, ftrace core code calls
ENABLE_SHARE_IPMODIFY_PEER on the DIRECT ops before registering the
IPMODIFY ops.

If IPMODIFY ops is attached before the DIRECT ops, ftrace core code calls
ENABLE_SHARE_IPMODIFY_SELF in __ftrace_hash_update_ipmodify. Owner of the
DIRECT ops may return 0 if the DIRECT trampoline can share with IPMODIFY,
so error code otherwise. The error code is propagated to
register_ftrace_direct_multi so that onwer of the DIRECT trampoline can
handle it properly.

For more details, please refer to comment before enum ftrace_ops_cmd.

Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/all/20220602193706.2607681-2-song@kernel.org/
Link: https://lore.kernel.org/all/20220718055449.3960512-1-song@kernel.org/
Link: https://lore.kernel.org/bpf/20220720002126.803253-3-song@kernel.org
2022-07-22 22:04:30 +02:00
Song Liu
f96f644ab9 ftrace: Add modify_ftrace_direct_multi_nolock
This is similar to modify_ftrace_direct_multi, but does not acquire
direct_mutex. This is useful when direct_mutex is already locked by the
user.

Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/bpf/20220720002126.803253-2-song@kernel.org
2022-07-22 22:04:24 +02:00
Linus Torvalds
4ba1329cbb Urgent RCU pull request for v5.19
This pull request contains a pair of commits that fix 282d8998e9 ("srcu:
 Prevent expedited GPs and blocking readers from consuming CPU"), which
 was itself a fix to an SRCU expedited grace-period problem that could
 prevent kernel live patching (KLP) from completing.  That SRCU fix for
 KLP introduced large (as in minutes) boot-time delays to embedded Linux
 kernels running on qemu/KVM.  These delays were due to the emulation of
 certain MMIO operations controlling memory layout, which were emulated
 with one expedited grace period per access.  Common configurations
 required thousands of boot-time MMIO accesses, and thus thousands of
 boot-time expedited SRCU grace periods.
 
 In these configurations, the occasional sleeps that allowed KLP to proceed
 caused excessive boot delays.  These commits preserve enough sleeps to
 permit KLP to proceed, but few enough that the virtual embedded kernels
 still boot reasonably quickly.
 
 This represents a regression introduced in the v5.19 merge window,
 and the bug is causing significant inconvenience, hence this pull request.
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Merge tag 'rcu-urgent.2022.07.21a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

Pull RCU fix from Paul McKenney:
 "This contains a pair of commits that fix 282d8998e9 ("srcu: Prevent
  expedited GPs and blocking readers from consuming CPU"), which was
  itself a fix to an SRCU expedited grace-period problem that could
  prevent kernel live patching (KLP) from completing.

  That SRCU fix for KLP introduced large (as in minutes) boot-time
  delays to embedded Linux kernels running on qemu/KVM. These delays
  were due to the emulation of certain MMIO operations controlling
  memory layout, which were emulated with one expedited grace period per
  access. Common configurations required thousands of boot-time MMIO
  accesses, and thus thousands of boot-time expedited SRCU grace
  periods.

  In these configurations, the occasional sleeps that allowed KLP to
  proceed caused excessive boot delays. These commits preserve enough
  sleeps to permit KLP to proceed, but few enough that the virtual
  embedded kernels still boot reasonably quickly.

  This represents a regression introduced in the v5.19 merge window, and
  the bug is causing significant inconvenience"

* tag 'rcu-urgent.2022.07.21a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu:
  srcu: Make expedited RCU grace periods block even less frequently
  srcu: Block less aggressively for expedited grace periods
2022-07-22 10:01:20 -07:00
David Gow
426752b253 kcsan: test: Add a .kunitconfig to run KCSAN tests
Add a .kunitconfig file, which provides a default, working config for
running the KCSAN tests. Note that it needs to run on an SMP machine, so
to run under kunit_tool, the --qemu_args option should be used (on a
supported architecture, like x86_64). For example:
./tools/testing/kunit/kunit.py run --arch=x86_64 --qemu_args='-smp 8'
					--kunitconfig=kernel/kcsan

Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Acked-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: Daniel Latypov <dlatypov@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2022-07-22 09:22:59 -06:00
Tianyu Lan
7231180903 swiotlb: clean up some coding style and minor issues
- Fix the used field of struct io_tlb_area wasn't initialized
- Set area number to be 0 if input area number parameter is 0
- Use array_size() to calculate io_tlb_area array size
- Make parameters of swiotlb_do_find_slots() more reasonable

Fixes: 26ffb91fa5e0 ("swiotlb: split up the global swiotlb lock")
Signed-off-by: Tianyu Lan <tiala@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2022-07-22 17:20:56 +02:00
Kumar Kartikeya Dwivedi
56e948ffc0 bpf: Add support for forcing kfunc args to be trusted
Teach the verifier to detect a new KF_TRUSTED_ARGS kfunc flag, which
means each pointer argument must be trusted, which we define as a
pointer that is referenced (has non-zero ref_obj_id) and also needs to
have its offset unchanged, similar to how release functions expect their
argument. This allows a kfunc to receive pointer arguments unchanged
from the result of the acquire kfunc.

This is required to ensure that kfunc that operate on some object only
work on acquired pointers and not normal PTR_TO_BTF_ID with same type
which can be obtained by pointer walking. The restrictions applied to
release arguments also apply to trusted arguments. This implies that
strict type matching (not deducing type by recursively following members
at offset) and OBJ_RELEASE offset checks (ensuring they are zero) are
used for trusted pointer arguments.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220721134245.2450-5-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-07-21 21:03:09 -07:00
Kumar Kartikeya Dwivedi
a4703e3184 bpf: Switch to new kfunc flags infrastructure
Instead of populating multiple sets to indicate some attribute and then
researching the same BTF ID in them, prepare a single unified BTF set
which indicates whether a kfunc is allowed to be called, and also its
attributes if any at the same time. Now, only one call is needed to
perform the lookup for both kfunc availability and its attributes.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220721134245.2450-4-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-07-21 20:59:42 -07:00
Paul E. McKenney
34bc7b454d Merge branch 'ctxt.2022.07.05a' into HEAD
ctxt.2022.07.05a: Linux-kernel memory model development branch.
2022-07-21 17:46:18 -07:00
Paul E. McKenney
d38c8fe483 Merge branches 'doc.2022.06.21a', 'fixes.2022.07.19a', 'nocb.2022.07.19a', 'poll.2022.07.21a', 'rcu-tasks.2022.06.21a' and 'torture.2022.06.21a' into HEAD
doc.2022.06.21a: Documentation updates.
fixes.2022.07.19a: Miscellaneous fixes.
nocb.2022.07.19a: Callback-offload updates.
poll.2022.07.21a: Polled grace-period updates.
rcu-tasks.2022.06.21a: Tasks RCU updates.
torture.2022.06.21a: Torture-test updates.
2022-07-21 17:43:16 -07:00
Zqiang
28787e04fb rcu: Add irqs-disabled indicator to expedited RCU CPU stall warnings
If a CPU has interrupts disabled continuously starting before the
beginning of a given expedited RCU grace period, that CPU will not
execute that grace period's IPI handler.  This will in turn mean
that the ->cpu_no_qs.b.exp field in that CPU's rcu_data structure
will continue to contain the boolean value false.

Knowing whether or not a CPU has had interrupts disabled can be helpful
when debugging an expedited RCU CPU stall warning, so this commit
adds a "D" indicator expedited RCU CPU stall warnings that signifies
that the corresponding CPU has had interrupts disabled throughout.

This capability was tested as follows:

runqemu kvm slirp nographic qemuparams="-m 4096 -smp 4"  bootparams=
"isolcpus=2,3 nohz_full=2,3 rcu_nocbs=2,3 rcutree.dump_tree=1
rcutorture.stall_cpu_holdoff=30 rcutorture.stall_cpu=40
rcutorture.stall_cpu_irqsoff=1 rcutorture.stall_cpu_block=0
rcutorture.stall_no_softlockup=1" -d

The rcu_torture_stall() function ran on CPU 1, which displays the "D"
as expected given the rcutorture.stall_cpu_irqsoff=1 module parameter:

............
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks:
{ 1-...D } 26467 jiffies s: 13317 root: 0x1/.
rcu: blocking rcu_node structures (internal RCU debug): l=1:0-1:0x2/.
Task dump for CPU 1:
task:rcu_torture_sta state:R  running task     stack:    0 pid:   76  ppid:     2 flags:0x00004008

Signed-off-by: Zqiang <qiang1.zhang@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-07-21 17:41:56 -07:00
Paul E. McKenney
82e445697d rcu: Diagnose extended sync_rcu_do_polled_gp() loops
This commit dumps out state when the sync_rcu_do_polled_gp() function
loops more than expected.  This is a debugging aid.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-07-21 17:41:56 -07:00
Zqiang
ef4f9d9b92 rcu: Put panic_on_rcu_stall() after expedited RCU CPU stall warnings
When a normal RCU CPU stall warning is encountered with the
panic_on_rcu_stall sysfs variable is set, the system panics only after
the stall warning is printed.  But when an expedited RCU CPU stall
warning is encountered with the panic_on_rcu_stall sysfs variable is
set, the system panics first, thus never printing the stall warning.
This commit therefore brings the expedited stall warning into line with
the normal stall warning by printing first and panicking afterwards.

Signed-off-by: Zqiang <qiang1.zhang@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-07-21 17:41:56 -07:00
Paul E. McKenney
11d62f0f43 rcutorture: Test polled expedited grace-period primitives
This commit adds tests of start_poll_synchronize_rcu_expedited() and
poll_state_synchronize_rcu_expedited().

Link: https://lore.kernel.org/all/20220121142454.1994916-1-bfoster@redhat.com/
Link: https://docs.google.com/document/d/1RNKWW9jQyfjxw2E8dsXVTdvZYh0HnYeSHDKog9jhdN8/edit?usp=sharing
Cc: Brian Foster <bfoster@redhat.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ian Kent <raven@themaw.net>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-07-21 17:41:56 -07:00
Paul E. McKenney
d96c52fe49 rcu: Add polled expedited grace-period primitives
This commit adds expedited grace-period functionality to RCU's polled
grace-period API, adding start_poll_synchronize_rcu_expedited() and
cond_synchronize_rcu_expedited(), which are similar to the existing
start_poll_synchronize_rcu() and cond_synchronize_rcu() functions,
respectively.

Note that although start_poll_synchronize_rcu_expedited() can be invoked
very early, the resulting expedited grace periods are not guaranteed
to start until after workqueues are fully initialized.  On the other
hand, both synchronize_rcu() and synchronize_rcu_expedited() can also
be invoked very early, and the resulting grace periods will be taken
into account as they occur.

[ paulmck: Apply feedback from Neeraj Upadhyay. ]

Link: https://lore.kernel.org/all/20220121142454.1994916-1-bfoster@redhat.com/
Link: https://docs.google.com/document/d/1RNKWW9jQyfjxw2E8dsXVTdvZYh0HnYeSHDKog9jhdN8/edit?usp=sharing
Cc: Brian Foster <bfoster@redhat.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ian Kent <raven@themaw.net>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-07-21 17:41:56 -07:00
Paul E. McKenney
e4333cb20f rcutorture: Verify that polled GP API sees synchronous grace periods
This commit causes rcu_torture_writer() to use WARN_ON_ONCE() to check
that the cookie returned by the current RCU flavor's ->get_gp_state()
function (get_state_synchronize_rcu() for vanilla RCU) causes that
flavor's ->poll_gp_state function (poll_state_synchronize_rcu() for
vanilla RCU) to unconditionally return true.

Note that a pair calls to synchronous grace-period-wait functions are
used.  This is necessary to account for partially overlapping normal and
expedited grace periods aligning in just the wrong way with polled API
invocations, which can cause those polled API invocations to ignore one or
the other of those partially overlapping grace periods.  It is unlikely
that this sort of ignored grace period will be a problem in production,
but rcutorture can make it happen quite within a few tens of seconds.

This commit is in preparation for polled expedited grace periods.

[ paulmck: Apply feedback from Frederic Weisbecker. ]

Link: https://lore.kernel.org/all/20220121142454.1994916-1-bfoster@redhat.com/
Link: https://docs.google.com/document/d/1RNKWW9jQyfjxw2E8dsXVTdvZYh0HnYeSHDKog9jhdN8/edit?usp=sharing
Cc: Brian Foster <bfoster@redhat.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ian Kent <raven@themaw.net>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-07-21 17:41:56 -07:00
Paul E. McKenney
7f4535366f rcu: Make Tiny RCU grace periods visible to polled APIs
This commit makes the Tiny RCU implementation of synchronize_rcu()
increment the rcu_ctrlblk.gp_seq counter, thus making both
synchronize_rcu() and synchronize_rcu_expedited() visible to
get_state_synchronize_rcu() and friends.

Link: https://lore.kernel.org/all/20220121142454.1994916-1-bfoster@redhat.com/
Link: https://docs.google.com/document/d/1RNKWW9jQyfjxw2E8dsXVTdvZYh0HnYeSHDKog9jhdN8/edit?usp=sharing
Cc: Brian Foster <bfoster@redhat.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ian Kent <raven@themaw.net>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-07-21 17:41:56 -07:00
Paul E. McKenney
dd04140531 rcu: Make polled grace-period API account for expedited grace periods
Currently, this code could splat:

	oldstate = get_state_synchronize_rcu();
	synchronize_rcu_expedited();
	WARN_ON_ONCE(!poll_state_synchronize_rcu(oldstate));

This situation is counter-intuitive and user-unfriendly.  After all, there
really was a perfectly valid full grace period right after the call to
get_state_synchronize_rcu(), so why shouldn't poll_state_synchronize_rcu()
know about it?

This commit therefore makes the polled grace-period API aware of expedited
grace periods in addition to the normal grace periods that it is already
aware of.  With this change, the above code is guaranteed not to splat.

Please note that the above code can still splat due to counter wrap on the
one hand and situations involving partially overlapping normal/expedited
grace periods on the other.  On 64-bit systems, the second is of course
much more likely than the first.  It is possible to modify this approach
to prevent overlapping grace periods from causing splats, but only at
the expense of greatly increasing the probability of counter wrap, as
in within milliseconds on 32-bit systems and within minutes on 64-bit
systems.

This commit is in preparation for polled expedited grace periods.

Link: https://lore.kernel.org/all/20220121142454.1994916-1-bfoster@redhat.com/
Link: https://docs.google.com/document/d/1RNKWW9jQyfjxw2E8dsXVTdvZYh0HnYeSHDKog9jhdN8/edit?usp=sharing
Cc: Brian Foster <bfoster@redhat.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ian Kent <raven@themaw.net>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-07-21 17:41:56 -07:00
Paul E. McKenney
bf95b2bc3e rcu: Switch polled grace-period APIs to ->gp_seq_polled
This commit switches the existing polled grace-period APIs to use a
new ->gp_seq_polled counter in the rcu_state structure.  An additional
->gp_seq_polled_snap counter in that same structure allows the normal
grace period kthread to interact properly with the !SMP !PREEMPT fastpath
through synchronize_rcu().  The first of the two to note the end of a
given grace period will make knowledge of this transition available to
the polled API.

This commit is in preparation for polled expedited grace periods.

[ paulmck: Fix use of rcu_state.gp_seq_polled to start normal grace period. ]

Link: https://lore.kernel.org/all/20220121142454.1994916-1-bfoster@redhat.com/
Link: https://docs.google.com/document/d/1RNKWW9jQyfjxw2E8dsXVTdvZYh0HnYeSHDKog9jhdN8/edit?usp=sharing
Cc: Brian Foster <bfoster@redhat.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ian Kent <raven@themaw.net>
Co-developed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-07-21 17:40:06 -07:00
Dan Williams
14b80582c4 resource: Introduce alloc_free_mem_region()
The core of devm_request_free_mem_region() is a helper that searches for
free space in iomem_resource and performs __request_region_locked() on
the result of that search. The policy choices of the implementation
conform to what CONFIG_DEVICE_PRIVATE users want which is memory that is
immediately marked busy, and a preference to search for the first-fit
free range in descending order from the top of the physical address
space.

CXL has a need for a similar allocator, but with the following tweaks:

1/ Search for free space in ascending order

2/ Search for free space relative to a given CXL window

3/ 'insert' rather than 'request' the new resource given downstream
   drivers from the CXL Region driver (like the pmem or dax drivers) are
   responsible for request_mem_region() when they activate the memory
   range.

Rework __request_free_mem_region() into get_free_mem_region() which
takes a set of GFR_* (Get Free Region) flags to control the allocation
policy (ascending vs descending), and "busy" policy (insert_resource()
vs request_region()).

As part of the consolidation of the legacy GFR_REQUEST_REGION case with
the new default of just inserting a new resource into the free space
some minor cleanups like not checking for NULL before calling
devres_free() (which does its own check) is included.

Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/linux-cxl/20220420143406.GY2120790@nvidia.com/
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/165784333333.1758207.13703329337805274043.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-21 17:19:25 -07:00
Jakub Kicinski
6e0e846ee2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
No conflicts.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-21 13:03:39 -07:00
Linus Torvalds
44e29e64cf watch-queue: remove spurious double semicolon
Sedat Dilek noticed that I had an extraneous semicolon at the end of a
line in the previous patch.

It's harmless, but unintentional, and while compilers just treat it as
an extra empty statement, for all I know some other tooling might warn
about it. So clean it up before other people notice too ;)

Fixes: 353f7988dd ("watchqueue: make sure to serialize 'wqueue->defunct' properly")
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
2022-07-21 10:30:14 -07:00
Dan Williams
974854ab07 cxl/acpi: Track CXL resources in iomem_resource
Recall that CXL capable address ranges, on ACPI platforms, are published
in the CEDT.CFMWS (CXL Early Discovery Table: CXL Fixed Memory Window
Structures). These windows represent both the actively mapped capacity
and the potential address space that can be dynamically assigned to a
new CXL decode configuration (region / interleave-set).

CXL endpoints like DDR DIMMs can be mapped at any physical address
including 0 and legacy ranges.

There is an expectation and requirement that the /proc/iomem interface
and the iomem_resource tree in the kernel reflect the full set of
platform address ranges. I.e. that every address range that platform
firmware and bus drivers enumerate be reflected as an iomem_resource
entry. The hard requirement to do this for CXL arises from the fact that
facilities like CONFIG_DEVICE_PRIVATE expect to be able to treat empty
iomem_resource ranges as free for software to use as proxy address
space. Without CXL publishing its potential address ranges in
iomem_resource, the CONFIG_DEVICE_PRIVATE mechanism may inadvertently
steal capacity reserved for runtime provisioning of new CXL regions.

So, iomem_resource needs to know about both active and potential CXL
resource ranges. The active CXL resources might already be reflected in
iomem_resource as "System RAM". insert_resource_expand_to_fit() handles
re-parenting "System RAM" underneath a CXL window.

The "_expand_to_fit()" behavior handles cases where a CXL window is not
a strict superset of an existing entry in the iomem_resource tree. The
"_expand_to_fit()" behavior is acceptable from the perspective of
resource allocation. The expansion happens because a conflicting
resource range is already populated, which means the resource boundary
expansion does not result in any additional free CXL address space being
made available. CXL address space allocation is always bounded by the
orginal unexpanded address range.

However, the potential for expansion does mean that something like
walk_iomem_res_desc(IORES_DESC_CXL...) can only return fuzzy answers on
corner case platforms that cause the resource tree to expand a CXL
window resource over a range that is not decoded by CXL. This would be
an odd platform configuration, but if it becomes a problem in practice
the CXL subsytem could just publish an API that returns definitive
answers.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/165784325943.1758207.5310344844375305118.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-21 08:40:01 -07:00
Stanislav Fomichev
aef9d4a34a bpf: Check attach_func_proto more carefully in check_helper_call
Syzkaller found a problem similar to d1a6edecc1 ("bpf: Check
attach_func_proto more carefully in check_return_code") where
attach_func_proto might be NULL:

RIP: 0010:check_helper_call+0x3dcb/0x8d50 kernel/bpf/verifier.c:7330
 do_check kernel/bpf/verifier.c:12302 [inline]
 do_check_common+0x6e1e/0xb980 kernel/bpf/verifier.c:14610
 do_check_main kernel/bpf/verifier.c:14673 [inline]
 bpf_check+0x661e/0xc520 kernel/bpf/verifier.c:15243
 bpf_prog_load+0x11ae/0x1f80 kernel/bpf/syscall.c:2620

With the following reproducer:

  bpf$BPF_PROG_RAW_TRACEPOINT_LOAD(0x5, &(0x7f0000000780)={0xf, 0x4, &(0x7f0000000040)=@framed={{}, [@call={0x85, 0x0, 0x0, 0xbb}]}, &(0x7f0000000000)='GPL\x00', 0x0, 0x0, 0x0, 0x0, 0x0, '\x00', 0x0, 0x2b, 0xffffffffffffffff, 0x8, 0x0, 0x0, 0x10, 0x0}, 0x80)

Let's do the same here, only check attach_func_proto for the prog types
where we are certain that attach_func_proto is defined.

Fixes: 69fd337a97 ("bpf: per-cgroup lsm flavor")
Reported-by: syzbot+0f8d989b1fba1addc5e0@syzkaller.appspotmail.com
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20220720164729.147544-1-sdf@google.com
2022-07-21 15:02:02 +02:00
Cruz Zhao
91caa5ae24 sched/core: Fix the bug that task won't enqueue into core tree when update cookie
In function sched_core_update_cookie(), a task will enqueue into the
core tree only when it enqueued before, that is, if an uncookied task
is cookied, it will not enqueue into the core tree until it enqueue
again, which will result in unnecessary force idle.

Here follows the scenario:
  CPU x and CPU y are a pair of SMT siblings.
  1. Start task a running on CPU x without sleeping, and task b and
     task c running on CPU y without sleeping.
  2. We create a cookie and share it to task a and task b, and then
     we create another cookie and share it to task c.
  3. Simpling core_forceidle_sum of task a and b from /proc/PID/sched

And we will find out that core_forceidle_sum of task a takes 30%
time of the sampling period, which shouldn't happen as task a and b
have the same cookie.

Then we migrate task a to CPU x', migrate task b and c to CPU y', where
CPU x' and CPU y' are a pair of SMT siblings, and sampling again, we
will found out that core_forceidle_sum of task a and b are almost zero.

To solve this problem, we enqueue the task into the core tree if it's
on rq.

Fixes: 6e33cad0af49("sched: Trivial core scheduling cookie management")
Signed-off-by: Cruz Zhao <CruzZhao@linux.alibaba.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1656403045-100840-2-git-send-email-CruzZhao@linux.alibaba.com
2022-07-21 10:39:39 +02:00
Nicolas Saenz Julienne
5c66d1b9b3 nohz/full, sched/rt: Fix missed tick-reenabling bug in dequeue_task_rt()
dequeue_task_rt() only decrements 'rt_rq->rt_nr_running' after having
called sched_update_tick_dependency() preventing it from re-enabling the
tick on systems that no longer have pending SCHED_RT tasks but have
multiple runnable SCHED_OTHER tasks:

  dequeue_task_rt()
    dequeue_rt_entity()
      dequeue_rt_stack()
        dequeue_top_rt_rq()
	  sub_nr_running()	// decrements rq->nr_running
	    sched_update_tick_dependency()
	      sched_can_stop_tick()	// checks rq->rt.rt_nr_running,
	      ...
        __dequeue_rt_entity()
          dec_rt_tasks()	// decrements rq->rt.rt_nr_running
	  ...

Every other scheduler class performs the operation in the opposite
order, and sched_update_tick_dependency() expects the values to be
updated as such. So avoid the misbehaviour by inverting the order in
which the above operations are performed in the RT scheduler.

Fixes: 76d92ac305 ("sched: Migrate sched to use new tick dependency mask model")
Signed-off-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Reviewed-by: Phil Auld <pauld@redhat.com>
Link: https://lore.kernel.org/r/20220628092259.330171-1-nsaenzju@redhat.com
2022-07-21 10:39:38 +02:00
Juri Lelli
ddfc710395 sched/deadline: Fix BUG_ON condition for deboosted tasks
Tasks the are being deboosted from SCHED_DEADLINE might enter
enqueue_task_dl() one last time and hit an erroneous BUG_ON condition:
since they are not boosted anymore, the if (is_dl_boosted()) branch is
not taken, but the else if (!dl_prio) is and inside this one we
BUG_ON(!is_dl_boosted), which is of course false (BUG_ON triggered)
otherwise we had entered the if branch above. Long story short, the
current condition doesn't make sense and always leads to triggering of a
BUG.

Fix this by only checking enqueue flags, properly: ENQUEUE_REPLENISH has
to be present, but additional flags are not a problem.

Fixes: 64be6f1f5f ("sched/deadline: Don't replenish from a !SCHED_DEADLINE entity")
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20220714151908.533052-1-juri.lelli@redhat.com
2022-07-21 10:35:28 +02:00
Fabio M. De Francesco
554694ba12 module: Replace kmap() with kmap_local_page()
kmap() is being deprecated in favor of kmap_local_page().

Two main problems with kmap(): (1) It comes with an overhead as mapping
space is restricted and protected by a global lock for synchronization and
(2) it also requires global TLB invalidation when the kmap’s pool wraps
and it might block when the mapping space is fully utilized until a slot
becomes available.

With kmap_local_page() the mappings are per thread, CPU local, can take
page faults, and can be called from any context (including interrupts).
Tasks can be preempted and, when scheduled to run again, the kernel
virtual addresses are restored and still valid.

kmap_local_page() is faster than kmap() in kernels with HIGHMEM enabled.

Since the use of kmap_local_page() in module_gzip_decompress() and in
module_xz_decompress() is safe (i.e., it does not break the strict rules
of use), it should be preferred over kmap().

Therefore, replace kmap() with kmap_local_page().

Tested on a QEMU/KVM x86_32 VM with 4GB RAM, booting kernels with
HIGHMEM64GB enabled. Modules compressed with XZ or GZIP decompress
properly.

Cc: Matthew Wilcox <willy@infradead.com>
Suggested-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-07-20 14:27:46 -07:00
Linus Torvalds
353f7988dd watchqueue: make sure to serialize 'wqueue->defunct' properly
When the pipe is closed, we mark the associated watchqueue defunct by
calling watch_queue_clear().  However, while that is protected by the
watchqueue lock, new watchqueue entries aren't actually added under that
lock at all: they use the pipe->rd_wait.lock instead, and looking up
that pipe happens without any locking.

The watchqueue code uses the RCU read-side section to make sure that the
wqueue entry itself hasn't disappeared, but that does not protect the
pipe_info in any way.

So make sure to actually hold the wqueue lock when posting watch events,
properly serializing against the pipe being torn down.

Reported-by: Noam Rathaus <noamr@ssd-disclosure.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-07-20 10:46:07 -07:00
Marc Zyngier
0fa72ed05e Merge branch irq/loongarch into irq/irqchip-next
* irq/loongarch:
  : .
  : Merge the long awaited IRQ support for the LoongArch architecture.
  :
  : From the cover letter:
  :
  : "Currently, LoongArch based processors (e.g. Loongson-3A5000)
  : can only work together with LS7A chipsets. The irq chips in
  : LoongArch computers include CPUINTC (CPU Core Interrupt
  : Controller), LIOINTC (Legacy I/O Interrupt Controller),
  : EIOINTC (Extended I/O Interrupt Controller), PCH-PIC (Main
  : Interrupt Controller in LS7A chipset), PCH-LPC (LPC Interrupt
  : Controller in LS7A chipset) and PCH-MSI (MSI Interrupt Controller)."
  :
  : Note that this comes with non-official, arch private ACPICA
  : definitions until the official ACPICA update is realeased.
  : .
  irqchip / ACPI: Introduce ACPI_IRQ_MODEL_LPIC for LoongArch
  irqchip: Add LoongArch CPU interrupt controller support
  irqchip: Add Loongson Extended I/O interrupt controller support
  irqchip/loongson-liointc: Add ACPI init support
  irqchip/loongson-pch-msi: Add ACPI init support
  irqchip/loongson-pch-pic: Add ACPI init support
  irqchip: Add Loongson PCH LPC controller support
  LoongArch: Prepare to support multiple pch-pic and pch-msi irqdomain
  LoongArch: Use ACPI_GENERIC_GSI for gsi handling
  genirq/generic_chip: Export irq_unmap_generic_chip
  ACPI: irq: Allow acpi_gsi_to_irq() to have an arch-specific fallback
  APCI: irq: Add support for multiple GSI domains
  LoongArch: Provisionally add ACPICA data structures

Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-07-20 15:26:05 +01:00
Paran Lee
c904cda044 genirq: Use for_each_action_of_desc in actions_show()
Refactor action_show() to use for_each_action_of_desc instead
of a similar open-coded loop.

Signed-off-by: Paran Lee <p4ranlee@gmail.com>
[maz: reword commit message]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220710112614.19410-1-p4ranlee@gmail.com
2022-07-20 15:21:32 +01:00
Jianmin Lv
d319a299f4 genirq/generic_chip: Export irq_unmap_generic_chip
Some irq controllers have to re-implement a private version for
irq_generic_chip_ops, because they have a different xlate to translate
hwirq. Export irq_unmap_generic_chip to allow reusing in drivers.

Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/1658314292-35346-5-git-send-email-lvjianmin@loongson.cn
2022-07-20 12:05:55 +01:00
Zqiang
0578e14c94 rcu/nocb: Avoid polling when my_rdp->nocb_head_rdp list is empty
Currently, if the 'rcu_nocb_poll' kernel boot parameter is enabled, all
rcuog kthreads enter polling mode.  However, if all of a given group
of rcuo kthreads correspond to CPUs that have been de-offloaded, the
corresponding rcuog kthread will nonetheless still wake up periodically,
unnecessarily consuming power and perturbing workloads.  Fortunately,
this situation is easily detected by the fact that the rcuog kthread's
CPU's rcu_data structure's ->nocb_head_rdp list is empty.

This commit saves power and avoids unnecessarily perturbing workloads
by putting an rcuog kthread to sleep during any time period when all of
its rcuo kthreads' CPUs are de-offloaded.

Co-developed-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Zqiang <qiang1.zhang@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Neeraj Upadhyay <quic_neeraju@quicinc.com>
2022-07-19 11:43:55 -07:00
Uladzislau Rezki (Sony)
8f489b4da5 rcu/nocb: Add option to opt rcuo kthreads out of RT priority
This commit introduces a RCU_NOCB_CPU_CB_BOOST Kconfig option that
prevents rcuo kthreads from running at real-time priority, even in
kernels built with RCU_BOOST.  This capability is important to devices
needing low-latency (as in a few milliseconds) response from expedited
RCU grace periods, but which are not running a classic real-time workload.
On such devices, permitting the rcuo kthreads to run at real-time priority
results in unacceptable latencies imposed on the application tasks,
which run as SCHED_OTHER.

See for example the following trace output:

<snip>
<...>-60 [006] d..1 2979.028717: rcu_batch_start: rcu_preempt CBs=34619 bl=270
<snip>

If that rcuop kthread were permitted to run at real-time SCHED_FIFO
priority, it would monopolize its CPU for hundreds of milliseconds
while invoking those 34619 RCU callback functions, which would cause an
unacceptably long latency spike for many application stacks on Android
platforms.

However, some existing real-time workloads require that callback
invocation run at SCHED_FIFO priority, for example, those running on
systems with heavy SCHED_OTHER background loads.  (It is the real-time
system's administrator's responsibility to make sure that important
real-time tasks run at a higher priority than do RCU's kthreads.)

Therefore, this new RCU_NOCB_CPU_CB_BOOST Kconfig option defaults to
"y" on kernels built with PREEMPT_RT and defaults to "n" otherwise.
The effect is to preserve current behavior for real-time systems, but for
other systems to allow expedited RCU grace periods to run with real-time
priority while continuing to invoke RCU callbacks as SCHED_OTHER.

As you would expect, this RCU_NOCB_CPU_CB_BOOST Kconfig option has no
effect except on CPUs with offloaded RCU callbacks.

Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Reviewed-by: Neeraj Upadhyay <quic_neeraju@quicinc.com>
2022-07-19 11:43:48 -07:00