Pull timer fix from Ingo Molnar:
"Fix false positive 'softirq work is pending' messages on -rt kernels,
caused by a buggy factoring-out of existing code"
* tag 'timers-urgent-2023-09-02' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
tick/rcu: Fix false positive "softirq work is pending" messages
Pull documentation updates from Jonathan Corbet:
"Documentation work keeps chugging along; this includes:
- Work from Carlos Bilbao to integrate rustdoc output into the
generated HTML documentation. This took some work to figure out how
to do it without slowing the docs build and without creating people
who don't have Rust installed, but Carlos got there
- Move the loongarch and mips architecture documentation under
Documentation/arch/
- Some more maintainer documentation from Jakub
... plus the usual assortment of updates, translations, and fixes"
* tag 'docs-6.6' of git://git.lwn.net/linux: (56 commits)
Docu: genericirq.rst: fix irq-example
input: docs: pxrc: remove reference to phoenix-sim
Documentation: serial-console: Fix literal block marker
docs/mm: remove references to hmm_mirror ops and clean typos
docs/zh_CN: correct regi_chg(),regi_add() to region_chg(),region_add()
Documentation: Fix typos
Documentation/ABI: Fix typos
scripts: kernel-doc: fix macro handling in enums
scripts: kernel-doc: parse DEFINE_DMA_UNMAP_[ADDR|LEN]
Documentation: riscv: Update boot image header since EFI stub is supported
Documentation: riscv: Add early boot document
Documentation: arm: Add bootargs to the table of added DT parameters
docs: kernel-parameters: Refer to the correct bitmap function
doc: update params of memhp_default_state=
docs: Add book to process/kernel-docs.rst
docs: sparse: fix invalid link addresses
docs: vfs: clean up after the iterate() removal
docs: Add a section on surveys to the researcher guidelines
docs: move mips under arch
docs: move loongarch under arch
...
In commit 0345691b24 ("tick/rcu: Stop allowing RCU_SOFTIRQ in idle") the
new function report_idle_softirq() was created by breaking code out of the
existing can_stop_idle_tick() for kernels v5.18 and newer.
In doing so, the code essentially went from a one conditional:
if (a && b && c)
warn();
to a three conditional:
if (!a)
return;
if (!b)
return;
if (!c)
return;
warn();
But that conversion got the condition for the RT specific
local_bh_blocked() wrong. The original condition was:
!local_bh_blocked()
but the conversion failed to negate it so it ended up as:
if (!local_bh_blocked())
return false;
This issue lay dormant until another fixup for the same commit was added
in commit a7e282c777 ("tick/rcu: Fix bogus ratelimit condition").
This commit realized the ratelimit was essentially set to zero instead
of ten, and hence *no* softirq pending messages would ever be issued.
Once this commit was backported via linux-stable, both the v6.1 and v6.4
preempt-rt kernels started printing out 10 instances of this at boot:
NOHZ tick-stop error: local softirq work is pending, handler #80!!!
Remove the negation and return when local_bh_blocked() evaluates to true to
bring the correct behaviour back.
Fixes: 0345691b24 ("tick/rcu: Stop allowing RCU_SOFTIRQ in idle")
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Reviewed-by: Wen Yang <wenyang.linux@foxmail.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230818200757.1808398-1-paul.gortmaker@windriver.com
Pull kunit updates from Shuah Khan:
- add support for running Rust documentation tests as KUnit tests
- make init, str, sync, types doctests compilable/testable
- add support for attributes API which include speed, modules
attributes, ability to filter and report attributes
- add support for marking tests slow using attributes API
- add attributes API documentation
- fix a wild-memory-access bug in kunit_filter_suites() and a possible
memory leak in kunit_filter_suites()
- add support for counting number of test suites in a module, list
action to kunit test modules, and test filtering on module tests
* tag 'linux-kselftest-kunit-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (25 commits)
kunit: fix struct kunit_attr header
kunit: replace KUNIT_TRIGGER_STATIC_STUB maro with KUNIT_STATIC_STUB_REDIRECT
kunit: Allow kunit test modules to use test filtering
kunit: Make 'list' action available to kunit test modules
kunit: Report the count of test suites in a module
kunit: fix uninitialized variables bug in attributes filtering
kunit: fix possible memory leak in kunit_filter_suites()
kunit: fix wild-memory-access bug in kunit_filter_suites()
kunit: Add documentation of KUnit test attributes
kunit: add tests for filtering attributes
kunit: time: Mark test as slow using test attributes
kunit: memcpy: Mark tests as slow using test attributes
kunit: tool: Add command line interface to filter and report attributes
kunit: Add ability to filter attributes
kunit: Add module attribute
kunit: Add speed attribute
kunit: Add test attributes API structure
MAINTAINERS: add Rust KUnit files to the KUnit entry
rust: support running Rust documentation tests as KUnit ones
rust: types: make doctests compilable/testable
...
Mark the time KUnit test, time64_to_tm_test_date_range, as slow using test
attributes.
This test ran relatively much slower than most other KUnit tests.
By marking this test as slow, the test can now be filtered using the KUnit
test attribute filtering feature. Example: --filter "speed>slow". This will
run only the tests that have speeds faster than slow. The slow attribute
will also be outputted in KTAP.
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Rae Moar <rmoar@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
The nanosecond-to-millisecond skew computation uses unsigned arithmetic,
which produces user-unfriendly large positive numbers for negative skews.
Therefore, use signed arithmetic for this computation in order to preserve
the negativity.
Reported-by: Chris Bainbridge <chris.bainbridge@gmail.com>
Reported-by: Feng Tang <feng.tang@intel.com>
Fixes: dd02926994 ("clocksource: Improve "skew is too large" messages")
Reviewed-by: Feng Tang <feng.tang@intel.com>
Tested-by: Chris Bainbridge <chris.bainbridge@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Pull hardening updates from Kees Cook:
"There are three areas of note:
A bunch of strlcpy()->strscpy() conversions ended up living in my tree
since they were either Acked by maintainers for me to carry, or got
ignored for multiple weeks (and were trivial changes).
The compiler option '-fstrict-flex-arrays=3' has been enabled
globally, and has been in -next for the entire devel cycle. This
changes compiler diagnostics (though mainly just -Warray-bounds which
is disabled) and potential UBSAN_BOUNDS and FORTIFY _warning_
coverage. In other words, there are no new restrictions, just
potentially new warnings. Any new FORTIFY warnings we've seen have
been fixed (usually in their respective subsystem trees). For more
details, see commit df8fc4e934.
The under-development compiler attribute __counted_by has been added
so that we can start annotating flexible array members with their
associated structure member that tracks the count of flexible array
elements at run-time. It is possible (likely?) that the exact syntax
of the attribute will change before it is finalized, but GCC and Clang
are working together to sort it out. Any changes can be made to the
macro while we continue to add annotations.
As an example of that last case, I have a treewide commit waiting with
such annotations found via Coccinelle:
https://git.kernel.org/linus/adc5b3cb48a049563dc673f348eab7b6beba8a9b
Also see commit dd06e72e68 for more details.
Summary:
- Fix KMSAN vs FORTIFY in strlcpy/strlcat (Alexander Potapenko)
- Convert strreplace() to return string start (Andy Shevchenko)
- Flexible array conversions (Arnd Bergmann, Wyes Karny, Kees Cook)
- Add missing function prototypes seen with W=1 (Arnd Bergmann)
- Fix strscpy() kerndoc typo (Arne Welzel)
- Replace strlcpy() with strscpy() across many subsystems which were
either Acked by respective maintainers or were trivial changes that
went ignored for multiple weeks (Azeem Shaikh)
- Remove unneeded cc-option test for UBSAN_TRAP (Nick Desaulniers)
- Add KUnit tests for strcat()-family
- Enable KUnit tests of FORTIFY wrappers under UML
- Add more complete FORTIFY protections for strlcat()
- Add missed disabling of FORTIFY for all arch purgatories.
- Enable -fstrict-flex-arrays=3 globally
- Tightening UBSAN_BOUNDS when using GCC
- Improve checkpatch to check for strcpy, strncpy, and fake flex
arrays
- Improve use of const variables in FORTIFY
- Add requested struct_size_t() helper for types not pointers
- Add __counted_by macro for annotating flexible array size members"
* tag 'hardening-v6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (54 commits)
netfilter: ipset: Replace strlcpy with strscpy
uml: Replace strlcpy with strscpy
um: Use HOST_DIR for mrproper
kallsyms: Replace all non-returning strlcpy with strscpy
sh: Replace all non-returning strlcpy with strscpy
of/flattree: Replace all non-returning strlcpy with strscpy
sparc64: Replace all non-returning strlcpy with strscpy
Hexagon: Replace all non-returning strlcpy with strscpy
kobject: Use return value of strreplace()
lib/string_helpers: Change returned value of the strreplace()
jbd2: Avoid printing outside the boundary of the buffer
checkpatch: Check for 0-length and 1-element arrays
riscv/purgatory: Do not use fortified string functions
s390/purgatory: Do not use fortified string functions
x86/purgatory: Do not use fortified string functions
acpi: Replace struct acpi_table_slit 1-element array with flex-array
clocksource: Replace all non-returning strlcpy with strscpy
string: use __builtin_memcpy() in strlcpy/strlcat
staging: most: Replace all non-returning strlcpy with strscpy
drm/i2c: tda998x: Replace all non-returning strlcpy with strscpy
...
Pull scheduler updates from Ingo Molnar:
"Scheduler SMP load-balancer improvements:
- Avoid unnecessary migrations within SMT domains on hybrid systems.
Problem:
On hybrid CPU systems, (processors with a mixture of
higher-frequency SMT cores and lower-frequency non-SMT cores),
under the old code lower-priority CPUs pulled tasks from the
higher-priority cores if more than one SMT sibling was busy -
resulting in many unnecessary task migrations.
Solution:
The new code improves the load balancer to recognize SMT cores
with more than one busy sibling and allows lower-priority CPUs
to pull tasks, which avoids superfluous migrations and lets
lower-priority cores inspect all SMT siblings for the busiest
queue.
- Implement the 'runnable boosting' feature in the EAS balancer:
consider CPU contention in frequency, EAS max util & load-balance
busiest CPU selection.
This improves CPU utilization for certain workloads, while leaves
other key workloads unchanged.
Scheduler infrastructure improvements:
- Rewrite the scheduler topology setup code by consolidating it into
the build_sched_topology() helper function and building it
dynamically on the fly.
- Resolve the local_clock() vs. noinstr complications by rewriting
the code: provide separate sched_clock_noinstr() and
local_clock_noinstr() functions to be used in instrumentation code,
and make sure it is all instrumentation-safe.
Fixes:
- Fix a kthread_park() race with wait_woken()
- Fix misc wait_task_inactive() bugs unearthed by the -rt merge:
- Fix UP PREEMPT bug by unifying the SMP and UP implementations
- Fix task_struct::saved_state handling
- Fix various rq clock update bugs, unearthed by turning on the rq
clock debugging code.
- Fix the PSI WINDOW_MIN_US trigger limit, which was easy to trigger
by creating enough cgroups, by removing the warnign and restricting
window size triggers to PSI file write-permission or
CAP_SYS_RESOURCE.
- Propagate SMT flags in the topology when removing degenerate domain
- Fix grub_reclaim() calculation bug in the deadline scheduler code
- Avoid resetting the min update period when it is unnecessary, in
psi_trigger_destroy().
- Don't balance a task to its current running CPU in load_balance(),
which was possible on certain NUMA topologies with overlapping
groups.
- Fix the sched-debug printing of rq->nr_uninterruptible
Cleanups:
- Address various -Wmissing-prototype warnings, as a preparation to
(maybe) enable this warning in the future.
- Remove unused code
- Mark more functions __init
- Fix shadow-variable warnings"
* tag 'sched-core-2023-06-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (50 commits)
sched/core: Avoid multiple calling update_rq_clock() in __cfsb_csd_unthrottle()
sched/core: Avoid double calling update_rq_clock() in __balance_push_cpu_stop()
sched/core: Fixed missing rq clock update before calling set_rq_offline()
sched/deadline: Update GRUB description in the documentation
sched/deadline: Fix bandwidth reclaim equation in GRUB
sched/wait: Fix a kthread_park race with wait_woken()
sched/topology: Mark set_sched_topology() __init
sched/fair: Rename variable cpu_util eff_util
arm64/arch_timer: Fix MMIO byteswap
sched/fair, cpufreq: Introduce 'runnable boosting'
sched/fair: Refactor CPU utilization functions
cpuidle: Use local_clock_noinstr()
sched/clock: Provide local_clock_noinstr()
x86/tsc: Provide sched_clock_noinstr()
clocksource: hyper-v: Provide noinstr sched_clock()
clocksource: hyper-v: Adjust hv_read_tsc_page_tsc() to avoid special casing U64_MAX
x86/vdso: Fix gettimeofday masking
math64: Always inline u128 version of mul_u64_u64_shr()
s390/time: Provide sched_clock_noinstr()
loongarch: Provide noinstr sched_clock_read()
...
Pull timer updates from Thomas Gleixner:
"Time, timekeeping and related device driver updates:
Core:
- A set of fixes, cleanups and enhancements to the posix timer code:
- Prevent another possible live lock scenario in the exit() path,
which affects POSIX_CPU_TIMERS_TASK_WORK enabled architectures.
- Fix a loop termination issue which was reported syzcaller/KSAN
in the posix timer ID allocation code.
That triggered a deeper look into the posix-timer code which
unearthed more small issues.
- Add missing READ/WRITE_ONCE() annotations
- Fix or remove completely outdated comments
- Document places which are subtle and completely undocumented.
- Add missing hrtimer modes to the trace event decoder
- Small cleanups and enhancements all over the place
Drivers:
- Rework the Hyper-V clocksource and sched clock setup code
- Remove a deprecated clocksource driver
- Small fixes and enhancements all over the place"
* tag 'timers-core-2023-06-26' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/tip/tip: (39 commits)
clocksource/drivers/cadence-ttc: Fix memory leak in ttc_timer_probe
dt-bindings: timers: Add Ralink SoCs timer
clocksource/drivers/hyper-v: Rework clocksource and sched clock setup
dt-bindings: timer: brcm,kona-timer: convert to YAML
clocksource/drivers/imx-gpt: Fold <soc/imx/timer.h> into its only user
clk: imx: Drop inclusion of unused header <soc/imx/timer.h>
hrtimer: Add missing sparse annotations to hrtimer locking
clocksource/drivers/imx-gpt: Use only a single name for functions
clocksource/drivers/loongson1: Move PWM timer to clocksource framework
dt-bindings: timer: Add Loongson-1 clocksource
MIPS: Loongson32: Remove deprecated PWM timer clocksource
clocksource/drivers/ingenic-timer: Use pm_sleep_ptr() macro
tracing/timer: Add missing hrtimer modes to decode_hrtimer_mode().
posix-timers: Add sys_ni_posix_timers() prototype
tick/rcu: Fix bogus ratelimit condition
alarmtimer: Remove unnecessary (void *) cast
alarmtimer: Remove unnecessary initialization of variable 'ret'
posix-timers: Refer properly to CONFIG_HIGH_RES_TIMERS
posix-timers: Polish coding style in a few places
posix-timers: Remove pointless comments
...
Sparse warns about lock imbalance vs. the hrtimer_base lock due to missing
sparse annotations:
kernel/time/hrtimer.c:175:33: warning: context imbalance in 'lock_hrtimer_base' - wrong count at exit
kernel/time/hrtimer.c:1301:28: warning: context imbalance in 'hrtimer_start_range_ns' - unexpected unlock
kernel/time/hrtimer.c:1336:28: warning: context imbalance in 'hrtimer_try_to_cancel' - unexpected unlock
kernel/time/hrtimer.c:1457:9: warning: context imbalance in '__hrtimer_get_remaining' - unexpected unlock
Add the annotations to the relevant functions.
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230621075928.394481-1-ben.dooks@codethink.co.uk
Commit c78f261e5dcb ("posix-timers: Clarify posix_timer_fn() comments")
turns an ifdef CONFIG_HIGH_RES_TIMERS into an conditional on
"IS_ENABLED(CONFIG_HIGHRES_TIMERS)"; note that the new conditional refers
to "HIGHRES_TIMERS" not "HIGH_RES_TIMERS" as before.
Fix this typo introduced in that refactoring.
Fixes: c78f261e5dcb ("posix-timers: Clarify posix_timer_fn() comments")
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230609094643.26253-1-lukas.bulwahn@gmail.com
