The :export: keyword makes sense only for C-files, where EXPORT_SYMBOL()
might appear. Otherwise kernel-doc may not produce anything out of this
file.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: f97fa3dcb2db ("lib/math: Move dvb_math.c into lib/math/int_log.c")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20230725104956.47806-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Some existing and new users may benefit from the intlog2() and intlog10() APIs, make them wide available. Reviewed-by: Mauro Carvalho Chehab <mchehab@kernel.org> Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org> Link: https://lore.kernel.org/r/20230619172019.21457-2-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/20230703135211.87416-2-andriy.shevchenko@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org>
Pull documentation updates from Jonathan Corbet:
"It's been a relatively calm cycle in docsland. We do have:
- Some initial page-table documentation from Linus (the other Linus)
- Regression-handling documentation improvements from Thorsten
- Addition of kerneldoc documentation for the ERR_PTR() and related
macros from James Seo
... and the usual collection of fixes and updates"
* tag 'docs-6.5' of git://git.lwn.net/linux:
docs: consolidate storage interfaces
Documentation: update git configuration for Link: tag
Documentation: KVM: make corrections to vcpu-requests.rst
Documentation: KVM: make corrections to ppc-pv.rst
Documentation: KVM: make corrections to locking.rst
Documentation: KVM: make corrections to halt-polling.rst
Documentation: virt: correct location of haltpoll module params
Documentation/mm: Initial page table documentation
docs: crypto: async-tx-api: fix typo in struct name
docs/doc-guide: Clarify how to write tables
docs: handling-regressions: rework section about fixing procedures
docs: process: fix a typoed cross-reference
docs: submitting-patches: Discuss interleaved replies
MAINTAINERS: direct process doc changes to a dedicated ML
Documentation: core-api: Add error pointer functions to kernel-api
err.h: Add missing kerneldocs for error pointer functions
Documentation: conf.py: Add __force to c_id_attributes
docs: clarify KVM related kernel parameters' descriptions
docs: consolidate human interface subsystems
docs: admin-guide: Add information about intel_pstate active mode
Bring the error pointer functions (e.g. ERR_PTR(), PTR_ERR()) into the docs build so that they can be cross-referenced elsewhere. List them as kernel library functions in the kernel-api document. Nowhere else seems to fit, and they need to go *somewhere*. Signed-off-by: James Seo <james@equiv.tech> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20230509175543.2065835-4-james@equiv.tech
Recent changes and additions to RCU have not been reflected in Documentation/core-api/kernel-api.rst, which makes it harder to find the kernel-doc headers in recently added RCU files. Therefore, add those files. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Liam Beguin <liambeguin@gmail.com> Cc: <linux-doc@vger.kernel.org>
Loading modules with finit_module() can end up using vmalloc(), vmap()
and vmalloc() again, for a total of up to 3 separate allocations in the
worst case for a single module. We always kernel_read*() the module,
that's a vmalloc(). Then vmap() is used for the module decompression,
and if so the last read buffer is freed as we use the now decompressed
module buffer to stuff data into our copy module. The last allocation is
specific to each architectures but pretty much that's generally a series
of vmalloc() calls or a variation of vmalloc to handle ELF sections with
special permissions.
Evaluation with new stress-ng module support [1] with just 100 ops
is proving that you can end up using GiBs of data easily even with all
care we have in the kernel and userspace today in trying to not load modules
which are already loaded. 100 ops seems to resemble the sort of pressure a
system with about 400 CPUs can create on module loading. Although issues
relating to duplicate module requests due to each CPU inucurring a new
module reuest is silly and some of these are being fixed, we currently lack
proper tooling to help diagnose easily what happened, when it happened
and who likely is to blame -- userspace or kernel module autoloading.
Provide an initial set of stats which use debugfs to let us easily scrape
post-boot information about failed loads. This sort of information can
be used on production worklaods to try to optimize *avoiding* redundant
memory pressure using finit_module().
There's a few examples that can be provided:
A 255 vCPU system without the next patch in this series applied:
Startup finished in 19.143s (kernel) + 7.078s (userspace) = 26.221s
graphical.target reached after 6.988s in userspace
And 13.58 GiB of virtual memory space lost due to failed module loading:
root@big ~ # cat /sys/kernel/debug/modules/stats
Mods ever loaded 67
Mods failed on kread 0
Mods failed on decompress 0
Mods failed on becoming 0
Mods failed on load 1411
Total module size 11464704
Total mod text size 4194304
Failed kread bytes 0
Failed decompress bytes 0
Failed becoming bytes 0
Failed kmod bytes 14588526272
Virtual mem wasted bytes 14588526272
Average mod size 171115
Average mod text size 62602
Average fail load bytes 10339140
Duplicate failed modules:
module-name How-many-times Reason
kvm_intel 249 Load
kvm 249 Load
irqbypass 8 Load
crct10dif_pclmul 128 Load
ghash_clmulni_intel 27 Load
sha512_ssse3 50 Load
sha512_generic 200 Load
aesni_intel 249 Load
crypto_simd 41 Load
cryptd 131 Load
evdev 2 Load
serio_raw 1 Load
virtio_pci 3 Load
nvme 3 Load
nvme_core 3 Load
virtio_pci_legacy_dev 3 Load
virtio_pci_modern_dev 3 Load
t10_pi 3 Load
virtio 3 Load
crc32_pclmul 6 Load
crc64_rocksoft 3 Load
crc32c_intel 40 Load
virtio_ring 3 Load
crc64 3 Load
The following screen shot, of a simple 8vcpu 8 GiB KVM guest with the
next patch in this series applied, shows 226.53 MiB are wasted in virtual
memory allocations which due to duplicate module requests during boot.
It also shows an average module memory size of 167.10 KiB and an an
average module .text + .init.text size of 61.13 KiB. The end shows all
modules which were detected as duplicate requests and whether or not
they failed early after just the first kernel_read*() call or late after
we've already allocated the private space for the module in
layout_and_allocate(). A system with module decompression would reveal
more wasted virtual memory space.
We should put effort now into identifying the source of these duplicate
module requests and trimming these down as much possible. Larger systems
will obviously show much more wasted virtual memory allocations.
root@kmod ~ # cat /sys/kernel/debug/modules/stats
Mods ever loaded 67
Mods failed on kread 0
Mods failed on decompress 0
Mods failed on becoming 83
Mods failed on load 16
Total module size 11464704
Total mod text size 4194304
Failed kread bytes 0
Failed decompress bytes 0
Failed becoming bytes 228959096
Failed kmod bytes 8578080
Virtual mem wasted bytes 237537176
Average mod size 171115
Average mod text size 62602
Avg fail becoming bytes 2758544
Average fail load bytes 536130
Duplicate failed modules:
module-name How-many-times Reason
kvm_intel 7 Becoming
kvm 7 Becoming
irqbypass 6 Becoming & Load
crct10dif_pclmul 7 Becoming & Load
ghash_clmulni_intel 7 Becoming & Load
sha512_ssse3 6 Becoming & Load
sha512_generic 7 Becoming & Load
aesni_intel 7 Becoming
crypto_simd 7 Becoming & Load
cryptd 3 Becoming & Load
evdev 1 Becoming
serio_raw 1 Becoming
nvme 3 Becoming
nvme_core 3 Becoming
t10_pi 3 Becoming
virtio_pci 3 Becoming
crc32_pclmul 6 Becoming & Load
crc64_rocksoft 3 Becoming
crc32c_intel 3 Becoming
virtio_pci_modern_dev 2 Becoming
virtio_pci_legacy_dev 1 Becoming
crc64 2 Becoming
virtio 2 Becoming
virtio_ring 2 Becoming
[0] https://github.com/ColinIanKing/stress-ng.git
[1] echo 0 > /proc/sys/vm/oom_dump_tasks
./stress-ng --module 100 --module-name xfs
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Commit d6f819908f8aac ("module: fold usermode helper kmod into modules
directory") moves kmod helper implementation (kmod.c) to kernel/module/
directory but forgets to update its reference on kernel api doc, hence:
WARNING: kernel-doc './scripts/kernel-doc -rst -enable-lineno -sphinx-version 2.4.4 -export ./kernel/kmod.c' failed with return code 2
Update the reference.
Fixes: d6f819908f8aac ("module: fold usermode helper kmod into modules directory")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Link: https://lore.kernel.org/linux-next/20230324154413.19cc78be@canb.auug.org.au/
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Reviewed-by: Liam Beguin <liambeguin@gmail.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Pull kernel hardening updates from Kees Cook:
- Convert flexible array members, fix -Wstringop-overflow warnings, and
fix KCFI function type mismatches that went ignored by maintainers
(Gustavo A. R. Silva, Nathan Chancellor, Kees Cook)
- Remove the remaining side-effect users of ksize() by converting
dma-buf, btrfs, and coredump to using kmalloc_size_roundup(), add
more __alloc_size attributes, and introduce full testing of all
allocator functions. Finally remove the ksize() side-effect so that
each allocation-aware checker can finally behave without exceptions
- Introduce oops_limit (default 10,000) and warn_limit (default off) to
provide greater granularity of control for panic_on_oops and
panic_on_warn (Jann Horn, Kees Cook)
- Introduce overflows_type() and castable_to_type() helpers for cleaner
overflow checking
- Improve code generation for strscpy() and update str*() kern-doc
- Convert strscpy and sigphash tests to KUnit, and expand memcpy tests
- Always use a non-NULL argument for prepare_kernel_cred()
- Disable structleak plugin in FORTIFY KUnit test (Anders Roxell)
- Adjust orphan linker section checking to respect CONFIG_WERROR (Xin
Li)
- Make sure siginfo is cleared for forced SIGKILL (haifeng.xu)
- Fix um vs FORTIFY warnings for always-NULL arguments
* tag 'hardening-v6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (31 commits)
ksmbd: replace one-element arrays with flexible-array members
hpet: Replace one-element array with flexible-array member
um: virt-pci: Avoid GCC non-NULL warning
signal: Initialize the info in ksignal
lib: fortify_kunit: build without structleak plugin
panic: Expose "warn_count" to sysfs
panic: Introduce warn_limit
panic: Consolidate open-coded panic_on_warn checks
exit: Allow oops_limit to be disabled
exit: Expose "oops_count" to sysfs
exit: Put an upper limit on how often we can oops
panic: Separate sysctl logic from CONFIG_SMP
mm/pgtable: Fix multiple -Wstringop-overflow warnings
mm: Make ksize() a reporting-only function
kunit/fortify: Validate __alloc_size attribute results
drm/sti: Fix return type of sti_{dvo,hda,hdmi}_connector_mode_valid()
drm/fsl-dcu: Fix return type of fsl_dcu_drm_connector_mode_valid()
driver core: Add __alloc_size hint to devm allocators
overflow: Introduce overflows_type() and castable_to_type()
coredump: Proactively round up to kmalloc bucket size
...
Pull documentation updates from Jonathan Corbet:
"This was a not-too-busy cycle for documentation; highlights include:
- The beginnings of a set of translations into Spanish, headed up by
Carlos Bilbao
- More Chinese translations
- A change to the Sphinx "alabaster" theme by default for HTML
generation.
Unlike the previous default (Read the Docs), alabaster is shipped
with Sphinx by default, reducing the number of other dependencies
that need to be installed. It also (IMO) produces a cleaner and
more readable result.
- The ability to render the documentation into the texinfo format
(something Sphinx could always do, we just never wired it up until
now)
Plus the usual collection of typo fixes, build-warning fixes, and
minor updates"
* tag 'docs-6.2' of git://git.lwn.net/linux: (67 commits)
Documentation/features: Use loongarch instead of loong
Documentation/features-refresh.sh: Only sed the beginning "arch" of ARCH_DIR
docs/zh_CN: Fix '.. only::' directive's expression
docs/sp_SP: Add memory-barriers.txt Spanish translation
docs/zh_CN/LoongArch: Update links of LoongArch ISA Vol1 and ELF psABI
docs/LoongArch: Update links of LoongArch ISA Vol1 and ELF psABI
Documentation/features: Update feature lists for 6.1
Documentation: Fixed a typo in bootconfig.rst
docs/sp_SP: Add process coding-style translation
docs/sp_SP: Add kernel-docs.rst Spanish translation
docs: Create translations/sp_SP/process/, move submitting-patches.rst
docs: Add book to process/kernel-docs.rst
docs: Retire old resources from kernel-docs.rst
docs: Update maintainer of kernel-docs.rst
Documentation: riscv: Document the sv57 VM layout
Documentation: USB: correct possessive "its" usage
math64: fix kernel-doc return value warnings
math64: add kernel-doc for DIV64_U64_ROUND_UP
math64: favor kernel-doc from header files
doc: add texinfodocs and infodocs targets
...
Fix the kernel-doc markings for div64 functions to point to the header file instead of the lib/ directory. This avoids having implementation specific comments in generic documentation. Furthermore, given that some kernel-doc comments are identical, drop them from lib/math64 and only keep there comments that add implementation details. Signed-off-by: Liam Beguin <liambeguin@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Tested-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/20221118182309.3824530-1-liambeguin@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>