Pull random number generator updates from Jason Donenfeld:
"Originally I'd planned on sending each of the vDSO getrandom()
architecture ports to their respective arch trees. But as we started
to work on this, we found lots of interesting issues in the shared
code and infrastructure, the fixes for which the various archs needed
to base their work.
So in the end, this turned into a nice collaborative effort fixing up
issues and porting to 5 new architectures -- arm64, powerpc64,
powerpc32, s390x, and loongarch64 -- with everybody pitching in and
commenting on each other's code. It was a fun development cycle.
This contains:
- Numerous fixups to the vDSO selftest infrastructure, getting it
running successfully on more platforms, and fixing bugs in it.
- Additions to the vDSO getrandom & chacha selftests. Basically every
time manual review unearthed a bug in a revision of an arch patch,
or an ambiguity, the tests were augmented.
By the time the last arch was submitted for review, s390x, v1 of
the series was essentially fine right out of the gate.
- Fixes to the the generic C implementation of vDSO getrandom, to
build and run successfully on all archs, decoupling it from
assumptions we had (unintentionally) made on x86_64 that didn't
carry through to the other architectures.
- Port of vDSO getrandom to LoongArch64, from Xi Ruoyao and acked by
Huacai Chen.
- Port of vDSO getrandom to ARM64, from Adhemerval Zanella and acked
by Will Deacon.
- Port of vDSO getrandom to PowerPC, in both 32-bit and 64-bit
varieties, from Christophe Leroy and acked by Michael Ellerman.
- Port of vDSO getrandom to S390X from Heiko Carstens, the arch
maintainer.
While it'd be natural for there to be things to fix up over the course
of the development cycle, these patches got a decent amount of review
from a fairly diverse crew of folks on the mailing lists, and, for the
most part, they've been cooking in linux-next, which has been helpful
for ironing out build issues.
In terms of architectures, I think that mostly takes care of the
important 64-bit archs with hardware still being produced and running
production loads in settings where vDSO getrandom is likely to help.
Arguably there's still RISC-V left, and we'll see for 6.13 whether
they find it useful and submit a port"
* tag 'random-6.12-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: (47 commits)
selftests: vDSO: check cpu caps before running chacha test
s390/vdso: Wire up getrandom() vdso implementation
s390/vdso: Move vdso symbol handling to separate header file
s390/vdso: Allow alternatives in vdso code
s390/module: Provide find_section() helper
s390/facility: Let test_facility() generate static branch if possible
s390/alternatives: Remove ALT_FACILITY_EARLY
s390/facility: Disable compile time optimization for decompressor code
selftests: vDSO: fix vdso_config for s390
selftests: vDSO: fix ELF hash table entry size for s390x
powerpc/vdso: Wire up getrandom() vDSO implementation on VDSO64
powerpc/vdso: Wire up getrandom() vDSO implementation on VDSO32
powerpc/vdso: Refactor CFLAGS for CVDSO build
powerpc/vdso32: Add crtsavres
mm: Define VM_DROPPABLE for powerpc/32
powerpc/vdso: Fix VDSO data access when running in a non-root time namespace
selftests: vDSO: don't include generated headers for chacha test
arm64: vDSO: Wire up getrandom() vDSO implementation
arm64: alternative: make alternative_has_cap_likely() VDSO compatible
selftests: vDSO: also test counter in vdso_test_chacha
...
Pull slab updates from Vlastimil Babka:
"This time it's mostly refactoring and improving APIs for slab users in
the kernel, along with some debugging improvements.
- kmem_cache_create() refactoring (Christian Brauner)
Over the years have been growing new parameters to
kmem_cache_create() where most of them are needed only for a small
number of caches - most recently the rcu_freeptr_offset parameter.
To avoid adding new parameters to kmem_cache_create() and adjusting
all its callers, or creating new wrappers such as
kmem_cache_create_rcu(), we can now pass extra parameters using the
new struct kmem_cache_args. Not explicitly initialized fields
default to values interpreted as unused.
kmem_cache_create() is for now a wrapper that works both with the
new form: kmem_cache_create(name, object_size, args, flags) and the
legacy form: kmem_cache_create(name, object_size, align, flags,
ctor)
- kmem_cache_destroy() waits for kfree_rcu()'s in flight (Vlastimil
Babka, Uladislau Rezki)
Since SLOB removal, kfree() is allowed for freeing objects
allocated by kmem_cache_create(). By extension kfree_rcu() as
allowed as well, which can allow converting simple call_rcu()
callbacks that only do kmem_cache_free(), as there was never a
kmem_cache_free_rcu() variant. However, for caches that can be
destroyed e.g. on module removal, the cache owners knew to issue
rcu_barrier() first to wait for the pending call_rcu()'s, and this
is not sufficient for pending kfree_rcu()'s due to its internal
batching optimizations. Ulad has provided a new
kvfree_rcu_barrier() and to make the usage less error-prone,
kmem_cache_destroy() calls it. Additionally, destroying
SLAB_TYPESAFE_BY_RCU caches now again issues rcu_barrier()
synchronously instead of using an async work, because the past
motivation for async work no longer applies. Users of custom
call_rcu() callbacks should however keep calling rcu_barrier()
before cache destruction.
- Debugging use-after-free in SLAB_TYPESAFE_BY_RCU caches (Jann Horn)
Currently, KASAN cannot catch UAFs in such caches as it is legal to
access them within a grace period, and we only track the grace
period when trying to free the underlying slab page. The new
CONFIG_SLUB_RCU_DEBUG option changes the freeing of individual
object to be RCU-delayed, after which KASAN can poison them.
- Delayed memcg charging (Shakeel Butt)
In some cases, the memcg is uknown at allocation time, such as
receiving network packets in softirq context. With
kmem_cache_charge() these may be now charged later when the user
and its memcg is known.
- Misc fixes and improvements (Pedro Falcato, Axel Rasmussen,
Christoph Lameter, Yan Zhen, Peng Fan, Xavier)"
* tag 'slab-for-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: (34 commits)
mm, slab: restore kerneldoc for kmem_cache_create()
io_uring: port to struct kmem_cache_args
slab: make __kmem_cache_create() static inline
slab: make kmem_cache_create_usercopy() static inline
slab: remove kmem_cache_create_rcu()
file: port to struct kmem_cache_args
slab: create kmem_cache_create() compatibility layer
slab: port KMEM_CACHE_USERCOPY() to struct kmem_cache_args
slab: port KMEM_CACHE() to struct kmem_cache_args
slab: remove rcu_freeptr_offset from struct kmem_cache
slab: pass struct kmem_cache_args to do_kmem_cache_create()
slab: pull kmem_cache_open() into do_kmem_cache_create()
slab: pass struct kmem_cache_args to create_cache()
slab: port kmem_cache_create_usercopy() to struct kmem_cache_args
slab: port kmem_cache_create_rcu() to struct kmem_cache_args
slab: port kmem_cache_create() to struct kmem_cache_args
slab: add struct kmem_cache_args
slab: s/__kmem_cache_create/do_kmem_cache_create/g
memcg: add charging of already allocated slab objects
mm/slab: Optimize the code logic in find_mergeable()
...
Pull RCU updates from Neeraj Upadhyay:
"Context tracking:
- rename context tracking state related symbols and remove references
to "dynticks" in various context tracking state variables and
related helpers
- force context_tracking_enabled_this_cpu() to be inlined to avoid
leaving a noinstr section
CSD lock:
- enhance CSD-lock diagnostic reports
- add an API to provide an indication of ongoing CSD-lock stall
nocb:
- update and simplify RCU nocb code to handle (de-)offloading of
callbacks only for offline CPUs
- fix RT throttling hrtimer being armed from offline CPU
rcutorture:
- remove redundant rcu_torture_ops get_gp_completed fields
- add SRCU ->same_gp_state and ->get_comp_state functions
- add generic test for NUM_ACTIVE_*RCU_POLL* for testing RCU and SRCU
polled grace periods
- add CFcommon.arch for arch-specific Kconfig options
- print number of update types in rcu_torture_write_types()
- add rcutree.nohz_full_patience_delay testing to the TREE07 scenario
- add a stall_cpu_repeat module parameter to test repeated CPU stalls
- add argument to limit number of CPUs a guest OS can use in
torture.sh
rcustall:
- abbreviate RCU CPU stall warnings during CSD-lock stalls
- Allow dump_cpu_task() to be called without disabling preemption
- defer printing stall-warning backtrace when holding rcu_node lock
srcu:
- make SRCU gp seq wrap-around faster
- add KCSAN checks for concurrent updates to ->srcu_n_exp_nodelay and
->reschedule_count which are used in heuristics governing
auto-expediting of normal SRCU grace periods and
grace-period-state-machine delays
- mark idle SRCU-barrier callbacks to help identify stuck
SRCU-barrier callback
rcu tasks:
- remove RCU Tasks Rude asynchronous APIs as they are no longer used
- stop testing RCU Tasks Rude asynchronous APIs
- fix access to non-existent percpu regions
- check processor-ID assumptions during chosen CPU calculation for
callback enqueuing
- update description of rtp->tasks_gp_seq grace-period sequence
number
- add rcu_barrier_cb_is_done() to identify whether a given
rcu_barrier callback is stuck
- mark idle Tasks-RCU-barrier callbacks
- add *torture_stats_print() functions to print detailed diagnostics
for Tasks-RCU variants
- capture start time of rcu_barrier_tasks*() operation to help
distinguish a hung barrier operation from a long series of barrier
operations
refscale:
- add a TINY scenario to support tests of Tiny RCU and Tiny
SRCU
- optimize process_durations() operation
rcuscale:
- dump stacks of stalled rcu_scale_writer() instances and
grace-period statistics when rcu_scale_writer() stalls
- mark idle RCU-barrier callbacks to identify stuck RCU-barrier
callbacks
- print detailed grace-period and barrier diagnostics on
rcu_scale_writer() hangs for Tasks-RCU variants
- warn if async module parameter is specified for RCU implementations
that do not have async primitives such as RCU Tasks Rude
- make all writer tasks report upon hang
- tolerate repeated GFP_KERNEL failure in rcu_scale_writer()
- use special allocator for rcu_scale_writer()
- NULL out top-level pointers to heap memory to avoid double-free
bugs on modprobe failures
- maintain per-task instead of per-CPU callbacks count to avoid any
issues with migration of either tasks or callbacks
- constify struct ref_scale_ops
Fixes:
- use system_unbound_wq for kfree_rcu work to avoid disturbing
isolated CPUs
Misc:
- warn on unexpected rcu_state.srs_done_tail state
- better define "atomic" for list_replace_rcu() and
hlist_replace_rcu() routines
- annotate struct kvfree_rcu_bulk_data with __counted_by()"
* tag 'rcu.release.v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux: (90 commits)
rcu: Defer printing stall-warning backtrace when holding rcu_node lock
rcu/nocb: Remove superfluous memory barrier after bypass enqueue
rcu/nocb: Conditionally wake up rcuo if not already waiting on GP
rcu/nocb: Fix RT throttling hrtimer armed from offline CPU
rcu/nocb: Simplify (de-)offloading state machine
context_tracking: Tag context_tracking_enabled_this_cpu() __always_inline
context_tracking, rcu: Rename rcu_dyntick trace event into rcu_watching
rcu: Update stray documentation references to rcu_dynticks_eqs_{enter, exit}()
rcu: Rename rcu_momentary_dyntick_idle() into rcu_momentary_eqs()
rcu: Rename rcu_implicit_dynticks_qs() into rcu_watching_snap_recheck()
rcu: Rename dyntick_save_progress_counter() into rcu_watching_snap_save()
rcu: Rename struct rcu_data .exp_dynticks_snap into .exp_watching_snap
rcu: Rename struct rcu_data .dynticks_snap into .watching_snap
rcu: Rename rcu_dynticks_zero_in_eqs() into rcu_watching_zero_in_eqs()
rcu: Rename rcu_dynticks_in_eqs_since() into rcu_watching_snap_stopped_since()
rcu: Rename rcu_dynticks_in_eqs() into rcu_watching_snap_in_eqs()
rcu: Rename rcu_dynticks_eqs_online() into rcu_watching_online()
context_tracking, rcu: Rename rcu_dynticks_curr_cpu_in_eqs() into rcu_is_watching_curr_cpu()
context_tracking, rcu: Rename rcu_dynticks_task*() into rcu_task*()
refscale: Constify struct ref_scale_ops
...
Pull cgroup updates from Tejun Heo:
- cpuset isolation improvements
- cpuset cgroup1 support is split into its own file behind the new
config option CONFIG_CPUSET_V1. This makes it the second controller
which makes cgroup1 support optional after memcg
- Handling of unavailable v1 controller handling improved during
cgroup1 mount operations
- union_find applied to cpuset. It makes code simpler and more
efficient
- Reduce spurious events in pids.events
- Cleanups and other misc changes
- Contains a merge of cgroup/for-6.11-fixes to receive cpuset fixes
that further changes build upon
* tag 'cgroup-for-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (34 commits)
cgroup: Do not report unavailable v1 controllers in /proc/cgroups
cgroup: Disallow mounting v1 hierarchies without controller implementation
cgroup/cpuset: Expose cpuset filesystem with cpuset v1 only
cgroup/cpuset: Move cpu.h include to cpuset-internal.h
cgroup/cpuset: add sefltest for cpuset v1
cgroup/cpuset: guard cpuset-v1 code under CONFIG_CPUSETS_V1
cgroup/cpuset: rename functions shared between v1 and v2
cgroup/cpuset: move v1 interfaces to cpuset-v1.c
cgroup/cpuset: move validate_change_legacy to cpuset-v1.c
cgroup/cpuset: move legacy hotplug update to cpuset-v1.c
cgroup/cpuset: add callback_lock helper
cgroup/cpuset: move memory_spread to cpuset-v1.c
cgroup/cpuset: move relax_domain_level to cpuset-v1.c
cgroup/cpuset: move memory_pressure to cpuset-v1.c
cgroup/cpuset: move common code to cpuset-internal.h
cgroup/cpuset: introduce cpuset-v1.c
selftest/cgroup: Make test_cpuset_prs.sh deal with pre-isolated CPUs
cgroup/cpuset: Account for boot time isolated CPUs
cgroup/cpuset: remove use_parent_ecpus of cpuset
cgroup/cpuset: remove fetch_xcpus
...
Pull kunit updates from Shuah Khan:
- a new int_pow test suite
- documentation update to clarify filename best practices
- kernel-doc fix for EXPORT_SYMBOL_IF_KUNIT
- change to build compile_commands.json automatically instead of
requiring a manual build
* tag 'linux_kselftest-kunit-6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
lib/math: Add int_pow test suite
kunit: tool: Build compile_commands.json
kunit: Fix kernel-doc for EXPORT_SYMBOL_IF_KUNIT
Documentation: KUnit: Update filename best practices
Pull x86 core update from Thomas Gleixner:
"Enable UBSAN traps for x86, which provides better reporting through
metadata encodeded into UD1"
* tag 'x86-core-2024-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/traps: Enable UBSAN traps on x86
Pull x86 build updates from Thomas Gleixner:
"Updates for KCOV instrumentation on x86:
- Prevent spurious KCOV coverage in common_interrupt()
- Fixup the KCOV Makefile directive which got stale due to a source
file rename
- Exclude stack unwinding from KCOV as it creates large amounts of
uninteresting coverage
- Provide a self test to validate that KCOV coverage of the interrupt
handling code starts not before preempt count got updated"
* tag 'x86-build-2024-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Ignore stack unwinding in KCOV
module: Fix KCOV-ignored file name
kcov: Add interrupt handling self test
x86/entry: Remove unwanted instrumentation in common_interrupt()
Pull debugobjects updates from Thomas Gleixner:
- Use the threshold to check for the pool refill condition and not the
run time recorded all time low fill value, which is lower than the
threshold and therefore causes refills to be delayed.
- KCSAN annotation updates and simplification of the fill_pool() code.
* tag 'core-debugobjects-2024-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
debugobjects: Remove redundant checks in fill_pool()
debugobjects: Fix conditions in fill_pool()
debugobjects: Fix the compilation attributes of some global variables
Pull timer updates from Thomas Gleixner:
"Core:
- Overhaul of posix-timers in preparation of removing the workaround
for periodic timers which have signal delivery ignored.
- Remove the historical extra jiffie in msleep()
msleep() adds an extra jiffie to the timeout value to ensure
minimal sleep time. The timer wheel ensures minimal sleep time
since the large rewrite to a non-cascading wheel, but the extra
jiffie in msleep() remained unnoticed. Remove it.
- Make the timer slack handling correct for realtime tasks.
The procfs interface is inconsistent and does neither reflect
reality nor conforms to the man page. Show the correct 0 slack for
real time tasks and enforce it at the core level instead of having
inconsistent individual checks in various timer setup functions.
- The usual set of updates and enhancements all over the place.
Drivers:
- Allow the ACPI PM timer to be turned off during suspend
- No new drivers
- The usual updates and enhancements in various drivers"
* tag 'timers-core-2024-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (43 commits)
ntp: Make sure RTC is synchronized when time goes backwards
treewide: Fix wrong singular form of jiffies in comments
cpu: Use already existing usleep_range()
timers: Rename next_expiry_recalc() to be unique
platform/x86:intel/pmc: Fix comment for the pmc_core_acpi_pm_timer_suspend_resume function
clocksource/drivers/jcore: Use request_percpu_irq()
clocksource/drivers/cadence-ttc: Add missing clk_disable_unprepare in ttc_setup_clockevent
clocksource/drivers/asm9260: Add missing clk_disable_unprepare in asm9260_timer_init
clocksource/drivers/qcom: Add missing iounmap() on errors in msm_dt_timer_init()
clocksource/drivers/ingenic: Use devm_clk_get_enabled() helpers
platform/x86:intel/pmc: Enable the ACPI PM Timer to be turned off when suspended
clocksource: acpi_pm: Add external callback for suspend/resume
clocksource/drivers/arm_arch_timer: Using for_each_available_child_of_node_scoped()
dt-bindings: timer: rockchip: Add rk3576 compatible
timers: Annotate possible non critical data race of next_expiry
timers: Remove historical extra jiffie for timeout in msleep()
hrtimer: Use and report correct timerslack values for realtime tasks
hrtimer: Annotate hrtimer_cpu_base_.*_expiry() for sparse.
timers: Add sparse annotation for timer_sync_wait_running().
signal: Replace BUG_ON()s
...
Pull irq updates from Thomas Gleixner:
"Core:
- Remove a global lock in the affinity setting code
The lock protects a cpumask for intermediate results and the lock
causes a bottleneck on simultaneous start of multiple virtual
machines. Replace the lock and the static cpumask with a per CPU
cpumask which is nicely serialized by raw spinlock held when
executing this code.
- Provide support for giving a suffix to interrupt domain names.
That's required to support devices with subfunctions so that the
domain names are distinct even if they originate from the same
device node.
- The usual set of cleanups and enhancements all over the place
Drivers:
- Support for longarch AVEC interrupt chip
- Refurbishment of the Armada driver so it can be extended for new
variants.
- The usual set of cleanups and enhancements all over the place"
* tag 'irq-core-2024-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (73 commits)
genirq: Use cpumask_intersects()
genirq/cpuhotplug: Use cpumask_intersects()
irqchip/apple-aic: Only access system registers on SoCs which provide them
irqchip/apple-aic: Add a new "Global fast IPIs only" feature level
irqchip/apple-aic: Skip unnecessary enabling of use_fast_ipi
dt-bindings: apple,aic: Document A7-A11 compatibles
irqdomain: Use IS_ERR_OR_NULL() in irq_domain_trim_hierarchy()
genirq/msi: Use kmemdup_array() instead of kmemdup()
genirq/proc: Change the return value for set affinity permission error
genirq/proc: Use irq_move_pending() in show_irq_affinity()
genirq/proc: Correctly set file permissions for affinity control files
genirq: Get rid of global lock in irq_do_set_affinity()
genirq: Fix typo in struct comment
irqchip/loongarch-avec: Add AVEC irqchip support
irqchip/loongson-pch-msi: Prepare get_pch_msi_handle() for AVECINTC
irqchip/loongson-eiointc: Rename CPUHP_AP_IRQ_LOONGARCH_STARTING
LoongArch: Architectural preparation for AVEC irqchip
LoongArch: Move irqchip function prototypes to irq-loongson.h
irqchip/loongson-pch-msi: Switch to MSI parent domains
softirq: Remove unused 'action' parameter from action callback
...
Pull netfs updates from Christian Brauner:
"This contains the work to improve read/write performance for the new
netfs library.
The main performance enhancing changes are:
- Define a structure, struct folio_queue, and a new iterator type,
ITER_FOLIOQ, to hold a buffer as a replacement for ITER_XARRAY. See
that patch for questions about naming and form.
ITER_FOLIOQ is provided as a replacement for ITER_XARRAY. The
problem with an xarray is that accessing it requires the use of a
lock (typically the RCU read lock) - and this means that we can't
supply iterate_and_advance() with a step function that might sleep
(crypto for example) without having to drop the lock between pages.
ITER_FOLIOQ is the iterator for a chain of folio_queue structs,
where each folio_queue holds a small list of folios. A folio_queue
struct is a simpler structure than xarray and is not subject to
concurrent manipulation by the VM. folio_queue is used rather than
a bvec[] as it can form lists of indefinite size, adding to one end
and removing from the other on the fly.
- Provide a copy_folio_from_iter() wrapper.
- Make cifs RDMA support ITER_FOLIOQ.
- Use folio queues in the write-side helpers instead of xarrays.
- Add a function to reset the iterator in a subrequest.
- Simplify the write-side helpers to use sheaves to skip gaps rather
than trying to work out where gaps are.
- In afs, make the read subrequests asynchronous, putting them into
work items to allow the next patch to do progressive
unlocking/reading.
- Overhaul the read-side helpers to improve performance.
- Fix the caching of a partial block at the end of a file.
- Allow a store to be cancelled.
Then some changes for cifs to make it use folio queues instead of
xarrays for crypto bufferage:
- Use raw iteration functions rather than manually coding iteration
when hashing data.
- Switch to using folio_queue for crypto buffers.
- Remove the xarray bits.
Make some adjustments to the /proc/fs/netfs/stats file such that:
- All the netfs stats lines begin 'Netfs:' but change this to
something a bit more useful.
- Add a couple of stats counters to track the numbers of skips and
waits on the per-inode writeback serialisation lock to make it
easier to check for this as a source of performance loss.
Miscellaneous work:
- Ensure that the sb_writers lock is taken around
vfs_{set,remove}xattr() in the cachefiles code.
- Reduce the number of conditional branches in netfs_perform_write().
- Move the CIFS_INO_MODIFIED_ATTR flag to the netfs_inode struct and
remove cifs_post_modify().
- Move the max_len/max_nr_segs members from netfs_io_subrequest to
netfs_io_request as they're only needed for one subreq at a time.
- Add an 'unknown' source value for tracing purposes.
- Remove NETFS_COPY_TO_CACHE as it's no longer used.
- Set the request work function up front at allocation time.
- Use bh-disabling spinlocks for rreq->lock as cachefiles completion
may be run from block-filesystem DIO completion in softirq context.
- Remove fs/netfs/io.c"
* tag 'vfs-6.12.netfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (25 commits)
docs: filesystems: corrected grammar of netfs page
cifs: Don't support ITER_XARRAY
cifs: Switch crypto buffer to use a folio_queue rather than an xarray
cifs: Use iterate_and_advance*() routines directly for hashing
netfs: Cancel dirty folios that have no storage destination
cachefiles, netfs: Fix write to partial block at EOF
netfs: Remove fs/netfs/io.c
netfs: Speed up buffered reading
afs: Make read subreqs async
netfs: Simplify the writeback code
netfs: Provide an iterator-reset function
netfs: Use new folio_queue data type and iterator instead of xarray iter
cifs: Provide the capability to extract from ITER_FOLIOQ to RDMA SGEs
iov_iter: Provide copy_folio_from_iter()
mm: Define struct folio_queue and ITER_FOLIOQ to handle a sequence of folios
netfs: Use bh-disabling spinlocks for rreq->lock
netfs: Set the request work function upon allocation
netfs: Remove NETFS_COPY_TO_CACHE
netfs: Reserve netfs_sreq_source 0 as unset/unknown
netfs: Move max_len/max_nr_segs from netfs_io_subrequest to netfs_io_stream
...
Depending on the architecture, building a 32-bit vDSO on a 64-bit kernel
is problematic when some system headers are included.
Minimise the amount of headers by moving needed items, such as
__{get,put}_unaligned_t, into dedicated common headers and in general
use more specific headers, similar to what was done in commit
8165b57bca ("linux/const.h: Extract common header for vDSO") and
commit 8c59ab839f ("lib/vdso: Enable common headers").
On some architectures this results in missing PAGE_SIZE, as was
described by commit 8b3843ae36 ("vdso/datapage: Quick fix - use
asm/page-def.h for ARM64"), so define this if necessary, in the same way
as done prior by commit cffaefd15a ("vdso: Use CONFIG_PAGE_SHIFT in
vdso/datapage.h").
Removing linux/time64.h leads to missing 'struct timespec64' in
x86's asm/pvclock.h. Add a forward declaration of that struct in
that file.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
With the current implementation, __cvdso_getrandom_data() calls
memset() on certain architectures, which is unexpected in the VDSO.
Rather than providing a memset(), simply rewrite opaque data
initialization to avoid memset().
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Same as for the gettimeofday CVDSO implementation, add c-getrandom-y to
ease the inclusion of lib/vdso/getrandom.c in architectures' VDSO
builds.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Performing SMP atomic operations on u64 fails on powerpc32:
CC drivers/char/random.o
In file included from <command-line>:
drivers/char/random.c: In function 'crng_reseed':
././include/linux/compiler_types.h:510:45: error: call to '__compiletime_assert_391' declared with attribute error: Need native word sized stores/loads for atomicity.
510 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
| ^
././include/linux/compiler_types.h:491:25: note: in definition of macro '__compiletime_assert'
491 | prefix ## suffix(); \
| ^~~~~~
././include/linux/compiler_types.h:510:9: note: in expansion of macro '_compiletime_assert'
510 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
| ^~~~~~~~~~~~~~~~~~~
././include/linux/compiler_types.h:513:9: note: in expansion of macro 'compiletime_assert'
513 | compiletime_assert(__native_word(t), \
| ^~~~~~~~~~~~~~~~~~
./arch/powerpc/include/asm/barrier.h:74:9: note: in expansion of macro 'compiletime_assert_atomic_type'
74 | compiletime_assert_atomic_type(*p); \
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
./include/asm-generic/barrier.h:172:55: note: in expansion of macro '__smp_store_release'
172 | #define smp_store_release(p, v) do { kcsan_release(); __smp_store_release(p, v); } while (0)
| ^~~~~~~~~~~~~~~~~~~
drivers/char/random.c:286:9: note: in expansion of macro 'smp_store_release'
286 | smp_store_release(&__arch_get_k_vdso_rng_data()->generation, next_gen + 1);
| ^~~~~~~~~~~~~~~~~
The kernel-side generation counter in the random driver is handled as an
unsigned long, not as a u64, in base_crng and struct crng.
But on the vDSO side, it needs to be an u64, not just an unsigned long,
in order to support a 32-bit vDSO atop a 64-bit kernel.
On kernel side, however, it is an unsigned long, hence a 32-bit value on
32-bit architectures, so just cast it to unsigned long for the
smp_store_release(). A side effect is that on big endian architectures
the store will be performed in the upper 32 bits. It is not an issue on
its own because the vDSO site doesn't mind the value, as it only checks
differences. Just make sure that the vDSO side checks the full 64 bits.
For that, the local current_generation has to be u64 as well.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Adds test suite for integer based power function which performs integer
exponentiation.
The test suite is designed to verify that the implementation of int_pow
correctly computes the power of a given base raised to a given exponent.
The tests check various scenarios and edge cases to ensure the accuracy
and reliability of the exponentiation function.
Updated commit with test information at commit time: Shuah Khan
Signed-off-by: Luis Felipe Hernandez <luis.hernandez093@gmail.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Define a data structure, struct folio_queue, to represent a sequence of
folios and a kernel-internal I/O iterator type, ITER_FOLIOQ, to allow a
list of folio_queue structures to be used to provide a buffer to
iov_iter-taking functions, such as sendmsg and recvmsg.
The folio_queue structure looks like:
struct folio_queue {
struct folio_batch vec;
u8 orders[PAGEVEC_SIZE];
struct folio_queue *next;
struct folio_queue *prev;
unsigned long marks;
unsigned long marks2;
};
It does not use a list_head so that next and/or prev can be set to NULL at
the ends of the list, allowing iov_iter-handling routines to determine that
they *are* the ends without needing to store a head pointer in the iov_iter
struct.
A folio_batch struct is used to hold the folio pointers which allows the
batch to be passed to batch handling functions. Two mark bits are
available per slot. The intention is to use at least one of them to mark
folios that need putting, but that might not be ultimately necessary.
Accessor functions are used to access the slots to do the masking and an
additional accessor function is used to indicate the size of the array.
The order of each folio is also stored in the structure to avoid the need
for iov_iter_advance() and iov_iter_revert() to have to query each folio to
find its size.
With careful barriering, this can be used as an extending buffer with new
folios inserted and new folio_queue structs added without the need for a
lock. Further, provided we always keep at least one struct in the buffer,
we can also remove consumed folios and consumed structs from the head end
as we without the need for locks.
[Questions/thoughts]
(1) To manage this, I need a head pointer, a tail pointer, a tail slot
number (assuming insertion happens at the tail end and the next
pointers point from head to tail). Should I put these into a struct
of their own, say "folio_queue_head" or "rolling_buffer"?
I will end up with two of these in netfs_io_request eventually, one
keeping track of the pagecache I'm dealing with for buffered I/O and
the other to hold a bounce buffer when we need one.
(2) Should I make the slots {folio,off,len} or bio_vec?
(3) This is intended to replace ITER_XARRAY eventually. Using an xarray
in I/O iteration requires the taking of the RCU read lock, doing
copying under the RCU read lock, walking the xarray (which may change
under us), handling retries and dealing with special values.
The advantage of ITER_XARRAY is that when we're dealing with the
pagecache directly, we don't need any allocation - but if we're doing
encrypted comms, there's a good chance we'd be using a bounce buffer
anyway.
This will require afs, erofs, cifs, orangefs and fscache to be
converted to not use this. afs still uses it for dirs and symlinks;
some of erofs usages should be easy to change, but there's one which
won't be so easy; ceph's use via fscache can be fixed by porting ceph
to netfslib; cifs is using xarray as a bounce buffer - that can be
moved to use sheaves instead; and orangefs has a similar problem to
erofs - maybe orangefs could use netfslib?
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Matthew Wilcox <willy@infradead.org>
cc: Jeff Layton <jlayton@kernel.org>
cc: Steve French <sfrench@samba.org>
cc: Ilya Dryomov <idryomov@gmail.com>
cc: Gao Xiang <xiang@kernel.org>
cc: Mike Marshall <hubcap@omnibond.com>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
cc: linux-afs@lists.infradead.org
cc: linux-cifs@vger.kernel.org
cc: ceph-devel@vger.kernel.org
cc: linux-erofs@lists.ozlabs.org
cc: devel@lists.orangefs.org
Link: https://lore.kernel.org/r/20240814203850.2240469-13-dhowells@redhat.com/ # v2
Signed-off-by: Christian Brauner <brauner@kernel.org>
fill_pool() checks locklessly at the beginning whether the pool has to be
refilled. After that it checks locklessly in a loop whether the free list
contains objects and repeats the refill check.
If both conditions are true, it acquires the pool lock and tries to move
objects from the free list to the pool repeating the same checks again.
There are two redundant issues with that:
1) The repeated check for the fill condition
2) The loop processing
The repeated check is pointless as it was just established that fill is
required. The condition has to be re-evaluated under the lock anyway.
The loop processing is not required either because there is practically
zero chance that a repeated attempt will succeed if the checks under the
lock terminate the moving of objects.
Remove the redundant check and replace the loop with a simple if condition.
[ tglx: Massaged change log ]
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20240904133944.2124-4-thunder.leizhen@huawei.com
fill_pool() uses 'obj_pool_min_free' to decide whether objects should be
handed back to the kmem cache. But 'obj_pool_min_free' records the lowest
historical value of the number of objects in the object pool and not the
minimum number of objects which should be kept in the pool.
Use 'debug_objects_pool_min_level' instead, which holds the minimum number
which was scaled to the number of CPUs at boot time.
[ tglx: Massage change log ]
Fixes: d26bf5056f ("debugobjects: Reduce number of pool_lock acquisitions in fill_pool()")
Fixes: 36c4ead6f6 ("debugobjects: Add global free list and the counter")
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20240904133944.2124-3-thunder.leizhen@huawei.com
1. Both debug_objects_pool_min_level and debug_objects_pool_size are
read-only after initialization, change attribute '__read_mostly' to
'__ro_after_init', and remove '__data_racy'.
2. Many global variables are read in the debug_stats_show() function, but
didn't mask KCSAN's detection. Add '__data_racy' for them.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20240904133944.2124-2-thunder.leizhen@huawei.com
