Pull misc updates from Andrew Morton:
"Updates to various subsystems which I help look after. lib, ocfs2,
fatfs, autofs, squashfs, procfs, etc. A relatively small amount of
material this time"
* tag 'mm-nonmm-stable-2022-08-06-2' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (72 commits)
scripts/gdb: ensure the absolute path is generated on initial source
MAINTAINERS: kunit: add David Gow as a maintainer of KUnit
mailmap: add linux.dev alias for Brendan Higgins
mailmap: update Kirill's email
profile: setup_profiling_timer() is moslty not implemented
ocfs2: fix a typo in a comment
ocfs2: use the bitmap API to simplify code
ocfs2: remove some useless functions
lib/mpi: fix typo 'the the' in comment
proc: add some (hopefully) insightful comments
bdi: remove enum wb_congested_state
kernel/hung_task: fix address space of proc_dohung_task_timeout_secs
lib/lzo/lzo1x_compress.c: replace ternary operator with min() and min_t()
squashfs: support reading fragments in readahead call
squashfs: implement readahead
squashfs: always build "file direct" version of page actor
Revert "squashfs: provide backing_dev_info in order to disable read-ahead"
fs/ocfs2: Fix spelling typo in comment
ia64: old_rr4 added under CONFIG_HUGETLB_PAGE
proc: fix test for "vsyscall=xonly" boot option
...
Pull MM updates from Andrew Morton:
"Most of the MM queue. A few things are still pending.
Liam's maple tree rework didn't make it. This has resulted in a few
other minor patch series being held over for next time.
Multi-gen LRU still isn't merged as we were waiting for mapletree to
stabilize. The current plan is to merge MGLRU into -mm soon and to
later reintroduce mapletree, with a view to hopefully getting both
into 6.1-rc1.
Summary:
- The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe
Lin, Yang Shi, Anshuman Khandual and Mike Rapoport
- Some kmemleak fixes from Patrick Wang and Waiman Long
- DAMON updates from SeongJae Park
- memcg debug/visibility work from Roman Gushchin
- vmalloc speedup from Uladzislau Rezki
- more folio conversion work from Matthew Wilcox
- enhancements for coherent device memory mapping from Alex Sierra
- addition of shared pages tracking and CoW support for fsdax, from
Shiyang Ruan
- hugetlb optimizations from Mike Kravetz
- Mel Gorman has contributed some pagealloc changes to improve
latency and realtime behaviour.
- mprotect soft-dirty checking has been improved by Peter Xu
- Many other singleton patches all over the place"
[ XFS merge from hell as per Darrick Wong in
https://lore.kernel.org/all/YshKnxb4VwXycPO8@magnolia/ ]
* tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (282 commits)
tools/testing/selftests/vm/hmm-tests.c: fix build
mm: Kconfig: fix typo
mm: memory-failure: convert to pr_fmt()
mm: use is_zone_movable_page() helper
hugetlbfs: fix inaccurate comment in hugetlbfs_statfs()
hugetlbfs: cleanup some comments in inode.c
hugetlbfs: remove unneeded header file
hugetlbfs: remove unneeded hugetlbfs_ops forward declaration
hugetlbfs: use helper macro SZ_1{K,M}
mm: cleanup is_highmem()
mm/hmm: add a test for cross device private faults
selftests: add soft-dirty into run_vmtests.sh
selftests: soft-dirty: add test for mprotect
mm/mprotect: fix soft-dirty check in can_change_pte_writable()
mm: memcontrol: fix potential oom_lock recursion deadlock
mm/gup.c: fix formatting in check_and_migrate_movable_page()
xfs: fail dax mount if reflink is enabled on a partition
mm/memcontrol.c: remove the redundant updating of stats_flush_threshold
userfaultfd: don't fail on unrecognized features
hugetlb_cgroup: fix wrong hugetlb cgroup numa stat
...
Pull driver core / kernfs updates from Greg KH:
"Here is the set of driver core and kernfs changes for 6.0-rc1.
The "biggest" thing in here is some scalability improvements for
kernfs for large systems. Other than that, included in here are:
- arch topology and cache info changes that have been reviewed and
discussed a lot.
- potential error path cleanup fixes
- deferred driver probe cleanups
- firmware loader cleanups and tweaks
- documentation updates
- other small things
All of these have been in the linux-next tree for a while with no
reported problems"
* tag 'driver-core-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (63 commits)
docs: embargoed-hardware-issues: fix invalid AMD contact email
firmware_loader: Replace kmap() with kmap_local_page()
sysfs docs: ABI: Fix typo in comment
kobject: fix Kconfig.debug "its" grammar
kernfs: Fix typo 'the the' in comment
docs: driver-api: firmware: add driver firmware guidelines. (v3)
arch_topology: Fix cache attributes detection in the CPU hotplug path
ACPI: PPTT: Leave the table mapped for the runtime usage
cacheinfo: Use atomic allocation for percpu cache attributes
drivers/base: fix userspace break from using bin_attributes for cpumap and cpulist
MAINTAINERS: Change mentions of mpm to olivia
docs: ABI: sysfs-devices-soc: Update Lee Jones' email address
docs: ABI: sysfs-class-pwm: Update Lee Jones' email address
Documentation/process: Add embargoed HW contact for LLVM
Revert "kernfs: Change kernfs_notify_list to llist."
ACPI: Remove the unused find_acpi_cpu_cache_topology()
arch_topology: Warn that topology for nested clusters is not supported
arch_topology: Add support for parsing sockets in /cpu-map
arch_topology: Set cluster identifier in each core/thread from /cpu-map
arch_topology: Limit span of cpu_clustergroup_mask()
...
This commit introduces the /sys/kernel/debug/shrinker debugfs interface
which provides an ability to observe the state of individual kernel memory
shrinkers.
Because the feature adds some memory overhead (which shouldn't be large
unless there is a huge amount of registered shrinkers), it's guarded by a
config option (enabled by default).
This commit introduces the "count" interface for each shrinker registered
in the system.
The output is in the following format:
<cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>...
<cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>...
...
To reduce the size of output on machines with many thousands cgroups, if
the total number of objects on all nodes is 0, the line is omitted.
If the shrinker is not memcg-aware or CONFIG_MEMCG is off, 0 is printed as
cgroup inode id. If the shrinker is not numa-aware, 0's are printed for
all nodes except the first one.
This commit gives debugfs entries simple numeric names, which are not very
convenient. The following commit in the series will provide shrinkers
with more meaningful names.
[akpm@linux-foundation.org: remove WARN_ON_ONCE(), per Roman]
Reported-by: syzbot+300d27c79fe6d4cbcc39@syzkaller.appspotmail.com
Link: https://lkml.kernel.org/r/20220601032227.4076670-3-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Acked-by: Muchun Song <songmuchun@bytedance.com>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Hillf Danton <hdanton@sina.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull cxl updates from Dan Williams:
"Compute Express Link (CXL) updates for this cycle.
The highlight is new driver-core infrastructure and CXL subsystem
changes for allowing lockdep to validate device_lock() usage. Thanks
to PeterZ for setting me straight on the current capabilities of the
lockdep API, and Greg acked it as well.
On the CXL ACPI side this update adds support for CXL _OSC so that
platform firmware knows that it is safe to still grant Linux native
control of PCIe hotplug and error handling in the presence of CXL
devices. A circular dependency problem was discovered between suspend
and CXL memory for cases where the suspend image might be stored in
CXL memory where that image also contains the PCI register state to
restore to re-enable the device. Disable suspend for now until an
architecture is defined to clarify that conflict.
Lastly a collection of reworks, fixes, and cleanups to the CXL
subsystem where support for snooping mailbox commands and properly
handling the "mem_enable" flow are the highlights.
Summary:
- Add driver-core infrastructure for lockdep validation of
device_lock(), and fixup a deadlock report that was previously
hidden behind the 'lockdep no validate' policy.
- Add CXL _OSC support for claiming native control of CXL hotplug and
error handling.
- Disable suspend in the presence of CXL memory unless and until a
protocol is identified for restoring PCI device context from memory
hosted on CXL PCI devices.
- Add support for snooping CXL mailbox commands to protect against
inopportune changes, like set-partition with the 'immediate' flag
set.
- Rework how the driver detects legacy CXL 1.1 configurations (CXL
DVSEC / 'mem_enable') before enabling new CXL 2.0 decode
configurations (CXL HDM Capability).
- Miscellaneous cleanups and fixes from -next exposure"
* tag 'cxl-for-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (47 commits)
cxl/port: Enable HDM Capability after validating DVSEC Ranges
cxl/port: Reuse 'struct cxl_hdm' context for hdm init
cxl/port: Move endpoint HDM Decoder Capability init to port driver
cxl/pci: Drop @info argument to cxl_hdm_decode_init()
cxl/mem: Merge cxl_dvsec_ranges() and cxl_hdm_decode_init()
cxl/mem: Skip range enumeration if mem_enable clear
cxl/mem: Consolidate CXL DVSEC Range enumeration in the core
cxl/pci: Move cxl_await_media_ready() to the core
cxl/mem: Validate port connectivity before dvsec ranges
cxl/mem: Fix cxl_mem_probe() error exit
cxl/pci: Drop wait_for_valid() from cxl_await_media_ready()
cxl/pci: Consolidate wait_for_media() and wait_for_media_ready()
cxl/mem: Drop mem_enabled check from wait_for_media()
nvdimm: Fix firmware activation deadlock scenarios
device-core: Kill the lockdep_mutex
nvdimm: Drop nd_device_lock()
ACPI: NFIT: Drop nfit_device_lock()
nvdimm: Replace lockdep_mutex with local lock classes
cxl: Drop cxl_device_lock()
cxl/acpi: Add root device lockdep validation
...
Pull more MM updates from Andrew Morton:
- Two follow-on fixes for the post-5.19 series "Use pageblock_order for
cma and alloc_contig_range alignment", from Zi Yan.
- A series of z3fold cleanups and fixes from Miaohe Lin.
- Some memcg selftests work from Michal Koutný <mkoutny@suse.com>
- Some swap fixes and cleanups from Miaohe Lin
- Several individual minor fixups
* tag 'mm-stable-2022-05-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (25 commits)
mm/shmem.c: suppress shift warning
mm: Kconfig: reorganize misplaced mm options
mm: kasan: fix input of vmalloc_to_page()
mm: fix is_pinnable_page against a cma page
mm: filter out swapin error entry in shmem mapping
mm/shmem: fix infinite loop when swap in shmem error at swapoff time
mm/madvise: free hwpoison and swapin error entry in madvise_free_pte_range
mm/swapfile: fix lost swap bits in unuse_pte()
mm/swapfile: unuse_pte can map random data if swap read fails
selftests: memcg: factor out common parts of memory.{low,min} tests
selftests: memcg: remove protection from top level memcg
selftests: memcg: adjust expected reclaim values of protected cgroups
selftests: memcg: expect no low events in unprotected sibling
selftests: memcg: fix compilation
mm/z3fold: fix z3fold_page_migrate races with z3fold_map
mm/z3fold: fix z3fold_reclaim_page races with z3fold_free
mm/z3fold: always clear PAGE_CLAIMED under z3fold page lock
mm/z3fold: put z3fold page back into unbuddied list when reclaim or migration fails
revert "mm/z3fold.c: allow __GFP_HIGHMEM in z3fold_alloc"
mm/z3fold: throw warning on failure of trylock_page in z3fold_alloc
...
Pull misc updates from Andrew Morton:
"The non-MM patch queue for this merge window.
Not a lot of material this cycle. Many singleton patches against
various subsystems. Most notably some maintenance work in ocfs2
and initramfs"
* tag 'mm-nonmm-stable-2022-05-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (65 commits)
kcov: update pos before writing pc in trace function
ocfs2: dlmfs: fix error handling of user_dlm_destroy_lock
ocfs2: dlmfs: don't clear USER_LOCK_ATTACHED when destroying lock
fs/ntfs: remove redundant variable idx
fat: remove time truncations in vfat_create/vfat_mkdir
fat: report creation time in statx
fat: ignore ctime updates, and keep ctime identical to mtime in memory
fat: split fat_truncate_time() into separate functions
MAINTAINERS: add Muchun as a memcg reviewer
proc/sysctl: make protected_* world readable
ia64: mca: drop redundant spinlock initialization
tty: fix deadlock caused by calling printk() under tty_port->lock
relay: remove redundant assignment to pointer buf
fs/ntfs3: validate BOOT sectors_per_clusters
lib/string_helpers: fix not adding strarray to device's resource list
kernel/crash_core.c: remove redundant check of ck_cmdline
ELF, uapi: fixup ELF_ST_TYPE definition
ipc/mqueue: use get_tree_nodev() in mqueue_get_tree()
ipc: update semtimedop() to use hrtimer
ipc/sem: remove redundant assignments
...
After commits 7b42f1041c ("mm: Kconfig: move swap and slab config
options to the MM section") and 519bcb7979 ("mm: Kconfig: group swap,
slab, hotplug and thp options into submenus") we now have nicely organized
mm related config options. I have noticed some that were still misplaced,
so this moves them from various places into the new structure:
VM_EVENT_COUNTERS, COMPAT_BRK, MMAP_ALLOW_UNINITIALIZED to mm/Kconfig and
general MM section.
SLUB_STATS to mm/Kconfig and the slab submenu.
DEBUG_SLAB, SLUB_DEBUG, SLUB_DEBUG_ON to mm/Kconfig.debug and the Kernel
hacking / Memory Debugging submenu.
Link: https://lkml.kernel.org/r/20220525112559.1139-1-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull KUnit updates from Shuah Khan:
"Several fixes, cleanups, and enhancements to tests and framework:
- introduce _NULL and _NOT_NULL macros to pointer error checks
- rework kunit_resource allocation policy to fix memory leaks when
caller doesn't specify free() function to be used when allocating
memory using kunit_add_resource() and kunit_alloc_resource() funcs.
- add ability to specify suite-level init and exit functions"
* tag 'linux-kselftest-kunit-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (41 commits)
kunit: tool: Use qemu-system-i386 for i386 runs
kunit: fix executor OOM error handling logic on non-UML
kunit: tool: update riscv QEMU config with new serial dependency
kcsan: test: use new suite_{init,exit} support
kunit: tool: Add list of all valid test configs on UML
kunit: take `kunit_assert` as `const`
kunit: tool: misc cleanups
kunit: tool: minor cosmetic cleanups in kunit_parser.py
kunit: tool: make parser stop overwriting status of suites w/ no_tests
kunit: tool: remove dead parse_crash_in_log() logic
kunit: tool: print clearer error message when there's no TAP output
kunit: tool: stop using a shell to run kernel under QEMU
kunit: tool: update test counts summary line format
kunit: bail out of test filtering logic quicker if OOM
lib/Kconfig.debug: change KUnit tests to default to KUNIT_ALL_TESTS
kunit: Rework kunit_resource allocation policy
kunit: fix debugfs code to use enum kunit_status, not bool
kfence: test: use new suite_{init/exit} support, add .kunitconfig
kunit: add ability to specify suite-level init and exit functions
kunit: rename print_subtest_{start,end} for clarity (s/subtest/suite)
...
Pull slab updates from Vlastimil Babka:
- Conversion of slub_debug stack traces to stackdepot, allowing more
useful debugfs-based inspection for e.g. memory leak debugging.
Allocation and free debugfs info now includes full traces and is
sorted by the unique trace frequency.
The stackdepot conversion was already attempted last year but
reverted by ae14c63a9f. The memory overhead (while not actually
enabled on boot) has been meanwhile solved by making the large
stackdepot allocation dynamic. The xfstest issues haven't been
reproduced on current kernel locally nor in -next, so the slab cache
layout changes that originally made that bug manifest were probably
not the root cause.
- Refactoring of dma-kmalloc caches creation.
- Trivial cleanups such as removal of unused parameters, fixes and
clarifications of comments.
- Hyeonggon Yoo joins as a reviewer.
* tag 'slab-for-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
MAINTAINERS: add myself as reviewer for slab
mm/slub: remove unused kmem_cache_order_objects max
mm: slab: fix comment for __assume_kmalloc_alignment
mm: slab: fix comment for ARCH_KMALLOC_MINALIGN
mm/slub: remove unneeded return value of slab_pad_check
mm/slab_common: move dma-kmalloc caches creation into new_kmalloc_cache()
mm/slub: remove meaningless node check in ___slab_alloc()
mm/slub: remove duplicate flag in allocate_slab()
mm/slub: remove unused parameter in setup_object*()
mm/slab.c: fix comments
slab, documentation: add description of debugfs files for SLUB caches
mm/slub: sort debugfs output by frequency of stack traces
mm/slub: distinguish and print stack traces in debugfs files
mm/slub: use stackdepot to save stack trace in objects
mm/slub: move struct track init out of set_track()
lib/stackdepot: allow requesting early initialization dynamically
mm/slub, kunit: Make slub_kunit unaffected by user specified flags
mm/slab: remove some unused functions
Pull random number generator updates from Jason Donenfeld:
"These updates continue to refine the work began in 5.17 and 5.18 of
modernizing the RNG's crypto and streamlining and documenting its
code.
New for 5.19, the updates aim to improve entropy collection methods
and make some initial decisions regarding the "premature next" problem
and our threat model. The cloc utility now reports that random.c is
931 lines of code and 466 lines of comments, not that basic metrics
like that mean all that much, but at the very least it tells you that
this is very much a manageable driver now.
Here's a summary of the various updates:
- The random_get_entropy() function now always returns something at
least minimally useful. This is the primary entropy source in most
collectors, which in the best case expands to something like RDTSC,
but prior to this change, in the worst case it would just return 0,
contributing nothing. For 5.19, additional architectures are wired
up, and architectures that are entirely missing a cycle counter now
have a generic fallback path, which uses the highest resolution
clock available from the timekeeping subsystem.
Some of those clocks can actually be quite good, despite the CPU
not having a cycle counter of its own, and going off-core for a
stamp is generally thought to increase jitter, something positive
from the perspective of entropy gathering. Done very early on in
the development cycle, this has been sitting in next getting some
testing for a while now and has relevant acks from the archs, so it
should be pretty well tested and fine, but is nonetheless the thing
I'll be keeping my eye on most closely.
- Of particular note with the random_get_entropy() improvements is
MIPS, which, on CPUs that lack the c0 count register, will now
combine the high-speed but short-cycle c0 random register with the
lower-speed but long-cycle generic fallback path.
- With random_get_entropy() now always returning something useful,
the interrupt handler now collects entropy in a consistent
construction.
- Rather than comparing two samples of random_get_entropy() for the
jitter dance, the algorithm now tests many samples, and uses the
amount of differing ones to determine whether or not jitter entropy
is usable and how laborious it must be. The problem with comparing
only two samples was that if the cycle counter was extremely slow,
but just so happened to be on the cusp of a change, the slowness
wouldn't be detected. Taking many samples fixes that to some
degree.
This, combined with the other improvements to random_get_entropy(),
should make future unification of /dev/random and /dev/urandom
maybe more possible. At the very least, were we to attempt it again
today (we're not), it wouldn't break any of Guenter's test rigs
that broke when we tried it with 5.18. So, not today, but perhaps
down the road, that's something we can revisit.
- We attempt to reseed the RNG immediately upon waking up from system
suspend or hibernation, making use of the various timestamps about
suspend time and such available, as well as the usual inputs such
as RDRAND when available.
- Batched randomness now falls back to ordinary randomness before the
RNG is initialized. This provides more consistent guarantees to the
types of random numbers being returned by the various accessors.
- The "pre-init injection" code is now gone for good. I suspect you
in particular will be happy to read that, as I recall you
expressing your distaste for it a few months ago. Instead, to avoid
a "premature first" issue, while still allowing for maximal amount
of entropy availability during system boot, the first 128 bits of
estimated entropy are used immediately as it arrives, with the next
128 bits being buffered. And, as before, after the RNG has been
fully initialized, it winds up reseeding anyway a few seconds later
in most cases. This resulted in a pretty big simplification of the
initialization code and let us remove various ad-hoc mechanisms
like the ugly crng_pre_init_inject().
- The RNG no longer pretends to handle the "premature next" security
model, something that various academics and other RNG designs have
tried to care about in the past. After an interesting mailing list
thread, these issues are thought to be a) mainly academic and not
practical at all, and b) actively harming the real security of the
RNG by delaying new entropy additions after a potential compromise,
making a potentially bad situation even worse. As well, in the
first place, our RNG never even properly handled the premature next
issue, so removing an incomplete solution to a fake problem was
particularly nice.
This allowed for numerous other simplifications in the code, which
is a lot cleaner as a consequence. If you didn't see it before,
https://lore.kernel.org/lkml/YmlMGx6+uigkGiZ0@zx2c4.com/ may be a
thread worth skimming through.
- While the interrupt handler received a separate code path years ago
that avoids locks by using per-cpu data structures and a faster
mixing algorithm, in order to reduce interrupt latency, input and
disk events that are triggered in hardirq handlers were still
hitting locks and more expensive algorithms. Those are now
redirected to use the faster per-cpu data structures.
- Rather than having the fake-crypto almost-siphash-based random32
implementation be used right and left, and in many places where
cryptographically secure randomness is desirable, the batched
entropy code is now fast enough to replace that.
- As usual, numerous code quality and documentation cleanups. For
example, the initialization state machine now uses enum symbolic
constants instead of just hard coding numbers everywhere.
- Since the RNG initializes once, and then is always initialized
thereafter, a pretty heavy amount of code used during that
initialization is never used again. It is now completely cordoned
off using static branches and it winds up in the .text.unlikely
section so that it doesn't reduce cache compactness after the RNG
is ready.
- A variety of functions meant for waiting on the RNG to be
initialized were only used by vsprintf, and in not a particularly
optimal way. Replacing that usage with a more ordinary setup made
it possible to remove those functions.
- A cleanup of how we warn userspace about the use of uninitialized
/dev/urandom and uninitialized get_random_bytes() usage.
Interestingly, with the change you merged for 5.18 that attempts to
use jitter (but does not block if it can't), the majority of users
should never see those warnings for /dev/urandom at all now, and
the one for in-kernel usage is mainly a debug thing.
- The file_operations struct for /dev/[u]random now implements
.read_iter and .write_iter instead of .read and .write, allowing it
to also implement .splice_read and .splice_write, which makes
splice(2) work again after it was broken here (and in many other
places in the tree) during the set_fs() removal. This was a bit of
a last minute arrival from Jens that hasn't had as much time to
bake, so I'll be keeping my eye on this as well, but it seems
fairly ordinary. Unfortunately, read_iter() is around 3% slower
than read() in my tests, which I'm not thrilled about. But Jens and
Al, spurred by this observation, seem to be making progress in
removing the bottlenecks on the iter paths in the VFS layer in
general, which should remove the performance gap for all drivers.
- Assorted other bug fixes, cleanups, and optimizations.
- A small SipHash cleanup"
* tag 'random-5.19-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: (49 commits)
random: check for signals after page of pool writes
random: wire up fops->splice_{read,write}_iter()
random: convert to using fops->write_iter()
random: convert to using fops->read_iter()
random: unify batched entropy implementations
random: move randomize_page() into mm where it belongs
random: remove mostly unused async readiness notifier
random: remove get_random_bytes_arch() and add rng_has_arch_random()
random: move initialization functions out of hot pages
random: make consistent use of buf and len
random: use proper return types on get_random_{int,long}_wait()
random: remove extern from functions in header
random: use static branch for crng_ready()
random: credit architectural init the exact amount
random: handle latent entropy and command line from random_init()
random: use proper jiffies comparison macro
random: remove ratelimiting for in-kernel unseeded randomness
random: move initialization out of reseeding hot path
random: avoid initializing twice in credit race
random: use symbolic constants for crng_init states
...
The CONFIG_WARN_ALL_UNSEEDED_RANDOM debug option controls whether the
kernel warns about all unseeded randomness or just the first instance.
There's some complicated rate limiting and comparison to the previous
caller, such that even with CONFIG_WARN_ALL_UNSEEDED_RANDOM enabled,
developers still don't see all the messages or even an accurate count of
how many were missed. This is the result of basically parallel
mechanisms aimed at accomplishing more or less the same thing, added at
different points in random.c history, which sort of compete with the
first-instance-only limiting we have now.
It turns out, however, that nobody cares about the first unseeded
randomness instance of in-kernel users. The same first user has been
there for ages now, and nobody is doing anything about it. It isn't even
clear that anybody _can_ do anything about it. Most places that can do
something about it have switched over to using get_random_bytes_wait()
or wait_for_random_bytes(), which is the right thing to do, but there is
still much code that needs randomness sometimes during init, and as a
geeneral rule, if you're not using one of the _wait functions or the
readiness notifier callback, you're bound to be doing it wrong just
based on that fact alone.
So warning about this same first user that can't easily change is simply
not an effective mechanism for anything at all. Users can't do anything
about it, as the Kconfig text points out -- the problem isn't in
userspace code -- and kernel developers don't or more often can't react
to it.
Instead, show the warning for all instances when CONFIG_WARN_ALL_UNSEEDED_RANDOM
is set, so that developers can debug things need be, or if it isn't set,
don't show a warning at all.
At the same time, CONFIG_WARN_ALL_UNSEEDED_RANDOM now implies setting
random.ratelimit_disable=1 on by default, since if you care about one
you probably care about the other too. And we can clean up usage around
the related urandom_warning ratelimiter as well (whose behavior isn't
changing), so that it properly counts missed messages after the 10
message threshold is reached.
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
This is in line with Documentation/dev-tools/kunit/style.rst.
Some of these tests predate that so they don't follow this convention.
With this and commit b0841b51ca ("kunit: arch/um/configs: Enable
KUNIT_ALL_TESTS by default"), kunit.py will now run these tests by
default. This hopefully makes it easier to run and maintain the tests.
If any of these were to start failing, people would notice much quicker.
Note: this commit doesn't update LINEAR_RANGES_TEST since that would
select its dependency (LINEAR_RANGES). We don't want KUNIT_ALL_TESTS
to enable anything other than test kconfigs.
Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Nico Pache <npache@redhat.com>
Acked-by: Nico Pache <npache@redhat.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
