Commit 1feda5eb77 ("drm/exynos: Use selected dma_dev default iommu
domain instead of a fake one") removed the code around creating a
custom IOMMU domain, but forgot to remove the stub.
Remove the iommu_dma_init_domain() stub as the function is no longer
referenced, and was also made private to the IOMMU DMA code.
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
u2fzero_fill_in_urb() allocates dev->urb with usb_alloc_urb(), but
u2fzero_probe() ignored its return value and only freed the URB from
u2fzero_remove().
If LED or hwrng registration fails after the URB allocation, probe returns
an error and the driver core does not call .remove(), leaking the URB. A
failed URB setup was also allowed to continue probing with an unusable
device.
Check the URB setup result and add the missing probe-error unwind so the
URB is freed before returning from later errors.
Signed-off-by: Myeonghun Pak <mhun512@gmail.com>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Dorjoy Chowdhury <dorjoychy111@gmail.com> says:
I came upon this "Ability to only open regular files" uapi feature
suggestion from
https://uapi-group.org/kernel-features/#ability-to-only-open-regular-files
and thought it would be something I could do as a first patch and get to
know the kernel code a bit better.
The following filesystems have been tested by building and booting the
kernel x86 bzImage in a Fedora 43 VM in QEMU. I have tested with
OPENAT2_REGULAR that regular files can be successfully opened and
non-regular files (directory, fifo etc) return -EFTYPE.
- btrfs
- NFS (loopback)
- SMB (loopback)
Christian Brauner (Amutable) <brauner@kernel.org>:
All atomic_open implementations were audited for OPENAT2_REGULAR handling.
Explicit checks were added to ceph, gfs2, nfs (v4), and cifs/smb — these
are the filesystems whose atomic_open can encounter an existing non-regular
file and would otherwise call finish_open() on it or return a misleading
error code. The checks allow these filesystems to return -EFTYPE directly
and avoid unnecessary open+close round-trips.
The remaining implementations (9p, fuse, vboxsf, nfs v2/v3) don't need
explicit checks. They only call finish_open() on freshly created files
(always S_IFREG) and use finish_no_open() for lookup hits, letting the
VFS catch non-regular files via the do_open() safety net. Notably, fuse
also validates the server response (S_ISREG check on the reply) before
reaching finish_open().
* patches from https://patch.msgid.link/20260328172314.45807-1-dorjoychy111@gmail.com:
kselftest/openat2: test for OPENAT2_REGULAR flag
openat2: new OPENAT2_REGULAR flag support
Link: https://patch.msgid.link/20260328172314.45807-1-dorjoychy111@gmail.com
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Just a happy path test.
Christian Brauner <brauner@kernel.org> says:
Update OPENAT2_REGULAR fallback define to match upper-32-bit UAPI value.
Port the test to the kselftest_harness TEST*/FIXTURE framework to match
the migrated openat2_test.c, and add a regression test ensuring
open()/openat() keep ignoring the internal __O_REGULAR carrier bit.
Signed-off-by: Dorjoy Chowdhury <dorjoychy111@gmail.com>
Link: https://patch.msgid.link/20260328172314.45807-3-dorjoychy111@gmail.com
Reviewed-by: Aleksa Sarai <aleksa@amutable.com>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
This flag indicates the path should be opened if it's a regular file.
This is useful to write secure programs that want to avoid being
tricked into opening device nodes with special semantics while thinking
they operate on regular files. This is a requested feature from the
uapi-group[1].
The previously introduced EFTYPE error code is returned when the path
doesn't refer to a regular file. For example, if openat2 is called on
path /dev/null with OPENAT2_REGULAR in the flag param, it will return
-EFTYPE.
When used in combination with O_CREAT, either the regular file is
created, or if the path already exists, it is opened if it's a regular
file. Otherwise, -EFTYPE is returned.
When OPENAT2_REGULAR is combined with O_DIRECTORY, -EINVAL is returned
as it doesn't make sense to open a path that is both a directory and a
regular file.
The UAPI bit lives in the upper 32 bits of open_how::flags
(((__u64)1 << 32)) so that open(2) and openat(2) -- whose @flags
argument is a C int -- cannot physically express it. This is a
structural guarantee, not a runtime mask: the bit is unrepresentable in
32 bits.
Because the rest of the VFS open path narrows to 32 bits in several
places (op->open_flag, f->f_flags, the unsigned open_flag argument of
i_op->atomic_open()), build_open_flags() translates OPENAT2_REGULAR
into a kernel-internal lower-32-bit carrier __O_REGULAR (bit 4, unused
as an O_* on every architecture) before the assignment to op->open_flag.
__O_REGULAR then rides through the existing channels exactly like
__FMODE_EXEC. do_dentry_open() strips it so it cannot leak back to
userspace via fcntl(F_GETFL).
Four BUILD_BUG_ON_MSG() invariants in build_open_flags() prevent any
future bit collision or accidental low-32 redefinition:
- VALID_OPEN_FLAGS fits in 32 bits.
- OPENAT2_REGULAR lives in the upper 32 bits.
- OPENAT2_REGULAR does not alias any open()/openat() flag.
- __O_REGULAR does not alias any user-visible flag.
[1]: https://uapi-group.org/kernel-features/#ability-to-only-open-regular-files
Christian Brauner <brauner@kernel.org> says:
Move OPENAT2_REGULAR to the upper 32 bits of open_how::flags with a
kernel-internal __O_REGULAR carrier so that open(2)/openat(2) cannot
encode the flag; add BUILD_BUG_ON_MSG() invariants and register
__O_REGULAR in the fcntl_init() allocation-uniqueness BUILD_BUG_ON()
(bit count 21 -> 22).
Signed-off-by: Dorjoy Chowdhury <dorjoychy111@gmail.com>
Link: https://patch.msgid.link/20260328172314.45807-2-dorjoychy111@gmail.com
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Aleksa Sarai <aleksa@amutable.com>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Use flush_work() instead of cancel_work_sync() to terminate pending IRQ
work in cs35l56_sdw_remove(). And flush_work() again after masking the
interrupts to flush any queueing that was racing with the masking. This is
the same sequence as cs35l56_sdw_system_suspend().
cs35l56_sdw_interrupt() takes the pm_runtime to prevent the bus powering-
down before the interrupt status can be read and handled. The work releases
this pm_runtime. So cancelling it, instead of flushing, could leave an
unbalanced pm_runtime.
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Fixes: e496112529 ("ASoC: cs35l56: Add driver for Cirrus Logic CS35L56")
Link: https://patch.msgid.link/20260521123057.988732-1-rf@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>
After commit feee6b2989 ("mm/memory_hotplug: shrink zones when
offlining memory"), __remove_pages() doesn't need the "zone" parameter
so the "page" variable is also unused. Remove the unused code to avoid
such build warning:
arch/loongarch/mm/init.c: In function 'arch_remove_memory':
arch/loongarch/mm/init.c:134:22: warning: variable 'page' set but not used [-Wunused-but-set-variable=]
134 | struct page *page = pfn_to_page(start_pfn);
Cc: <stable@vger.kernel.org>
Reviewed-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Validate the relocation address against the initrd region specified via
"initrd=" or "initrdmem=" on the command line. Reject relocation targets
that overlap the initrd to prevent memory corruption during early boot.
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: WANG Rui <wangrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
When the kernel is relocated during early boot (efistub or kexec_file),
a randomized load address may has already been selected and applied. In
this case, performing KASLR again in relocate.c is unnecessary.
Note: strictly-defined KASLR means the kernel's final runtime address
has a random offset from the kernel's load address, which is implemented
in relocate.c; broadly-defined KALSR means the kernel's final runtime
address has a random offset from the kernel's link address (a.k.a.
VMLINUX_LOAD_ADDRESS), which also include the efistlub implementation,
kexec_file implementation and QEMU direct kernel boot. kaslr_disabled()
return true only means strictly-defined KASLR is disabled.
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: WANG Rui <wangrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Introduce efi_get_kimg_kaslr_address() helper to compute the preferred
kernel image load address dynamically when CONFIG_RANDOMIZE_BASE is
enabled. The function derives a random offset by using the EFI-provided
randomness combined with the timer tick value, and constrains it within
CONFIG_RANDOMIZE_BASE_MAX_OFFSET.
Update EFI_KIMG_PREFERRED_ADDRESS to call this helper so that the EFI
stub can select a randomized load address when KASLR is active, while
preserving the original base address behavior when KASLR is disabled or
"nokaslr" is specified.
Note: LoongArch can't KASLR for hibernation, so set efi_nokaslr to true
if "resume=<devname>" is explicitly specified in cmdline.
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: WANG Rui <wangrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
As the output file is currently never created, the check will run every
time, even if the inputs have not changed.
Create an empty output file which allows make to skip the execution when
it is not necessary.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Link: https://patch.msgid.link/20260520-tracing-ringbuffer-check-v1-1-d979cfab1338@weissschuh.net
Fixes: 1211907ac0 ("tracing: Generate undef symbols allowlist for simple_ring_buffer")
Fixes: 58b4bd1839 ("tracing: Adjust cmd_check_undefined to show unexpected undefined symbols")
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Currently there's a lot of silent error-return paths in various places
where nhi_probe() can fail. Sprinkle some prints to make it clearer
where the problem is.
Signed-off-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Because of how fundamental ops->init_interrupts() is, it no longer
makes sense to consider cases where nhi->ops is NULL.
Drop some boilerplate around it and add a single sanity-check in
nhi_probe() instead.
Signed-off-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Add a new file encapsulating most of the PCI NHI specifics
(intentionally leaving some odd cookies behind to make the layering
simpler). Most notably, separate out nhi_probe() to make it easier to
register other types of NHIs.
Also, fold in Intel Icelake (nhi_ops.c) support to contain all
PCIe-related bits in pci.c.
Signed-off-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Not all USB4/TB implementations are based on a PCIe-attached
controller. In order to make way for these, start off with moving the
pci_device reference out of the main tb_nhi structure.
Encapsulate the existing struct in a new tb_nhi_pci, that shall also
house all properties that relate to the parent bus. Similarly, any
other type of controller will be expected to contain tb_nhi as a
member.
Signed-off-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
The unload_page callback expects the return value of load_page() as its
argument: ret = load_page(va); unload(ret). Fix the rollback code in
simple_ring_buffer_init_mm() where the descriptor's VA is used instead
of the loaded page address.
Link: https://patch.msgid.link/20260512141614.1759430-1-vdonnefort@google.com
Fixes: 635923081c ("tracing: load/unload page callbacks for simple_ring_buffer")
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
nr_subbufs in the ring buffer metadata is always initialized to zero
because it is assigned from cpu_buffer->nr_pages before the page
initialization loop has run. While nr_subbufs is not currently read
by the kernel, it should reflect the actual buffer geometry in the
meta page for correctness.
Move the assignment after the page loop so that cpu_buffer->nr_pages
holds the final count.
Link: https://patch.msgid.link/20260512135420.99194-1-devnexen@gmail.com
Fixes: 34e5b958bd ("tracing: Introduce simple_ring_buffer")
Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Assisted-by: Claude:claude-opus-4-7
Signed-off-by: David Carlier <devnexen@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
On real hardware, panic and machine reboot may not flush hardware cache
to memory. This means the persistent ring buffer, which relies on a
coherent state of memory, may not have its events written to the buffer
and they may be lost. Moreover, there may be inconsistency with the
counters which are used for validation of the integrity of the
persistent ring buffer which may cause all data to be discarded.
To avoid this issue, stop recording of the ring buffer on panic and
flush the cache of the ring buffer's memory.
Fixes: e645535a95 ("tracing: Add option to use memmapped memory for trace boot instance")
Cc: stable@vger.kernel.org
Cc: Will Deacon <will@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Ian Rogers <irogers@google.com>
Link: https://patch.msgid.link/177751969602.2136606.12031934362587643488.stgit@mhiramat.tok.corp.google.com
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When tracing is active while reading the trace file, if the iterator
reading the buffer detects that the writer has passed the iterator head,
it will reset and set a "missed events" flag. This flag is passed to the
output processing to show the user that events were missed:
CPU:4 [LOST EVENTS]
The problem is that the flag is reset after it is checked in
ring_buffer_iter_dropped(). But the "trace" file iterates over all the CPU
ring buffers and it will check if they are dropped when figuring out which
buffer to print next. This prematurely clears the missed_events flag if
the CPU buffer with the missed events is not the one that is printed next.
On the iteration where the CPU buffer with the missed events is printed,
the check if it had missed events would return false and the output does
not show that events were missed.
Do not reset the missed_events flag when checking if there were missed
events, but instead clear it when moving the iterator head to the next
event.
Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://patch.msgid.link/20260520220801.4fd09d13@fedora
Fixes: c9b7a4a72f ("ring-buffer/tracing: Have iterator acknowledge dropped events")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Fix the pidfd leak in kselftest_harness.h's __wait_for_test() where
childfd = syscall(__NR_pidfd_open, t->pid, 0) is never closed.
Fixes: 73a3cde976 ("selftests: harness: Implement test timeouts through pidfd")
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Link: https://patch.msgid.link/a82e275ccfb2609a1984d90ab559fa3af78f1e81.1776678050.git.tanggeliang@kylinos.cn
Reviewed-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
When a buffer is freed either by LRU eviction or because it is unset,
the lockref is marked as dead instantly, which prevents the buffer from
being used after finding it in the buffer hash in xfs_buf_lookup and
xfs_buf_find_insert. But the latter will then not add the new buffer to
the hash because it already found an existing buffer.
Fix this using in two places: Remove the buffer from the hash before
marking the lockref dead so that that no buffer with a dead lockref can
be found in the hash, but if we find one in xfs_buf_find_insert due to
store reordering, handle this case correctly instead of returning an
unhashed buffer.
Fixes: 67fe430397 ("xfs: don't keep a reference for buffers on the LRU")
Reported-by: Andrey Albershteyn <aalbersh@redhat.com>
Reported-by: Carlos Maiolino <cem@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andrey Albershteyn <aalbersh@kernel.org>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
Both GNU and BSD makes share a "token pipe" between their instances, as
a result a -j $BIGNUM invocation results in multicore perf problems in
the poll handler.
Avoiding the store will reduce it a little bit. However, the crux of the
problem is the locked queuing up in poll_wait().
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://patch.msgid.link/20260516021852.256932-1-mjguzik@gmail.com
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Symlinks can't appear as opened file.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Link: https://patch.msgid.link/295235c7-7f68-4554-bb6f-85398beca350@p183
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Drop the hard-coded length argument and use the simpler QSTR(). Inline
the code and drop the local variable.
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Link: https://patch.msgid.link/20260505114242.158883-2-thorsten.blum@linux.dev
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Christoph Hellwig <hch@lst.de> says:
Due to an almost comical failure on my part, my work in progress test
case failed to create any file system on a 64k block size loop device,
and then tried to mount it, leading to a probe of file system built
into my kernel. Roughly the first half of the series are file systems
that actually crashed, but I fixed up all the pattern of missing
error handling that I saw.
* patches from https://patch.msgid.link/20260511071701.2456211-1-hch@lst.de:
omfs: handle set_blocksize failures
ntfs3: handle set_blocksize failures
minix: handle set_blocksize failures
isofs: handle set_blocksize failures
affs: handle set_blocksize failures
befs: handle set_blocksize failures
jfs: handle set_blocksize failures
qnx4: handle set_blocksize failures
hpfs: handle set_blocksize failures
bfs: handle set_blocksize failures
Link: https://patch.msgid.link/20260511071701.2456211-1-hch@lst.de
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
omfs uses buffer_heads, which don't handle block size > PAGE_SIZE well.
Without this, mounting we will hit the
BUG_ON(offset >= folio_size(folio));
in folio_set_bh on the first __bread_gfp call.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260511071701.2456211-11-hch@lst.de
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
ntfs3 uses buffer_heads, which don't handle block size > PAGE_SIZE well.
Without this, mounting we will hit the
BUG_ON(offset >= folio_size(folio));
in folio_set_bh on the first __bread_gfp call.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260511071701.2456211-10-hch@lst.de
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
minix uses buffer_heads, which don't handle block size > PAGE_SIZE well.
Without this, mounting we will hit the
BUG_ON(offset >= folio_size(folio));
in folio_set_bh on the first __bread_gfp call.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260511071701.2456211-9-hch@lst.de
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
isofs uses buffer_heads, which don't handle block size > PAGE_SIZE well.
Without this, mounting we will hit the
BUG_ON(offset >= folio_size(folio));
in folio_set_bh on the first __bread_gfp call.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260511071701.2456211-8-hch@lst.de
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
affs uses buffer_heads, which don't handle block size > PAGE_SIZE well.
Without this, mounting we will hit the
BUG_ON(offset >= folio_size(folio));
in folio_set_bh on the first __bread_gfp call.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260511071701.2456211-7-hch@lst.de
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
befs uses buffer_heads, which don't handle block size > PAGE_SIZE well.
Without this, mounting we will hit the
BUG_ON(offset >= folio_size(folio));
in folio_set_bh on the first __bread_gfp call.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260511071701.2456211-6-hch@lst.de
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
jfs uses buffer_heads, which don't handle block size > PAGE_SIZE well.
Without this, mounting we will hit the
BUG_ON(offset >= folio_size(folio));
in folio_set_bh on the first __bread_gfp call.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260511071701.2456211-5-hch@lst.de
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
qnx4 uses buffer_heads, which don't handle block size > PAGE_SIZE well.
Without this, mounting will hit the
BUG_ON(offset >= folio_size(folio));
in folio_set_bh on the first __bread_gfp call.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260511071701.2456211-4-hch@lst.de
Acked-by: Anders Larsen <al@alarsen.net>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
hpfs uses buffer_heads, which don't handle block size > PAGE_SIZE well.
Without this, mounting will hit the
BUG_ON(offset >= folio_size(folio));
in folio_set_bh on the first __bread_gfp call.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260511071701.2456211-3-hch@lst.de
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
bfs uses buffer_heads, which don't handle block size > PAGE_SIZE well.
Without this, mounting will hit the
BUG_ON(offset >= folio_size(folio));
in folio_set_bh on the first __bread_gfp call.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260511071701.2456211-2-hch@lst.de
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
This document is motivated by the ongoing maintenance burden that
abandoned and untestable filesystems impose on VFS developers, blocking
infrastructure changes such as folio conversions and iomap migration.
This week alone, two new filesystems were proposed on linux-fsdevel
(VMUFAT and FTRFS), highlighting the need for documented guidelines
that new filesystem authors can refer to before submission.
Multiple recent discussions on linux-fsdevel have touched on the
criteria for merging new filesystems and for deprecating old ones,
covering topics such as modern VFS interface adoption, testability,
userspace utilities, maintainer commitment, and user base viability.
Add Documentation/filesystems/adding-new-filesystems.rst describing
the technical requirements and community expectations for merging a
new filesystem into the kernel. The guidelines cover:
- Alternatives to consider before proposing a new in-kernel filesystem
- Technical requirements: modern VFS interfaces (iomap, folios,
fs_context mount API), testability, and userspace utilities
- Community expectations: identified maintainers, demonstrated
commitment, sustained backing, and a clear user base
- Ongoing obligations after merging, including the risk of deprecation
for unmaintained filesystems
Link: https://lore.kernel.org/linux-fsdevel/20260411151155.321214-1-adrianmcmenamin@gmail.com/
Link: https://lore.kernel.org/linux-fsdevel/20260413142357.515792-1-aurelien@hackers.camp/
Link: https://lore.kernel.org/linux-fsdevel/yndtg2jbj55fzd2kkhsmel4pp5ll5xfvfiaqh24tdct3jiqosd@jzbfzf3rrxrd/
Link: https://lore.kernel.org/linux-fsdevel/20260124091742.GA43313@macsyma.local/
Link: https://lore.kernel.org/lkml/20260111140345.3866-1-linkinjeon@kernel.org/
Cc: Christian Brauner <brauner@kernel.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jan Kara <jack@suse.cz>
Cc: Theodore Tso <tytso@mit.edu>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Assisted-by: Cursor:claude-4-opus
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://patch.msgid.link/20260422125212.1743006-1-amir73il@gmail.com
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
If d_flags isn't what we expect, then it's good to display it. Add a new
DENTRY_WARN_ONCE() macro that also displays d_flags for the dentry.
Change D_FLAG_VERIFY() to call that instead of a generic WARN_ON_ONCE().
Change the existing hlist_unhashed() check in dentry_free() to use the
new macro, and add checks for other invariants of a dead dentry. Notably:
1) Ensure that DCACHE_LRU_LIST and DCACHE_SHRINK_LIST are not set.
2) Ensure that d_lockref is negative
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260422-dcache-warn-v1-1-50155e1b40b6@kernel.org
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Currently, writing to 'core_pattern' or 'suid_dumpable' sysctl nodes
always triggers validate_coredump_safety(), even if the values have
not changed. This results in redundant warning messages in dmesg:
"Unsafe core_pattern used with fs.suid_dumpable=2..."
This patch optimizes the procfs handlers to only invoke the safety
validation when an actual change in the configuration is detected:
1. In proc_dostring_coredump(), compare the new core_pattern string
with the existing one using strncmp().
2. In proc_dointvec_minmax_coredump(), check if the new suid_dumpable
value differs from the previous one.
This keeps the kernel log clean from repetitive warnings when
re-applying the same sysctl settings.
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Link: https://patch.msgid.link/20260410080918.2319-1-lirongqing@baidu.com
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com> says:
This series is a preparation for
diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
index 23ff24080dfd..aebd3a5e90af 100644
--- a/include/linux/mod_devicetable.h
+++ b/include/linux/mod_devicetable.h
@@ -477,7 +477,11 @@ struct rpmsg_device_id {
struct i2c_device_id {
char name[I2C_NAME_SIZE];
- kernel_ulong_t driver_data; /* Data private to the driver */
+ union {
+ /* Data private to the driver */
+ kernel_ulong_t driver_data;
+ const void *driver_data_ptr;
+ };
};
/* pci_epf */
and this requires that .driver_data is assigned via a named initializer
for static data. This requirement isn't a bad one because named
initializers are also much better readable than list initializers.
The union added to struct i2c_device_id enables further cleanups like:
diff --git a/drivers/iio/accel/kxcjk-1013.c b/drivers/iio/accel/kxcjk-1013.c
index 8a082ff034dd..b2aac7348d22 100644
--- a/drivers/iio/accel/kxcjk-1013.c
+++ b/drivers/iio/accel/kxcjk-1013.c
@@ -1429,7 +1429,7 @@ static int kxcjk1013_probe(struct i2c_client *client)
if (id) {
name = id->name;
- data->info = (const struct kx_chipset_info *)(id->driver_data);
+ data->info = id->driver_data_ptr;
} else {
name = iio_get_acpi_device_name_and_data(&client->dev, &ddata);
data->info = ddata;
@@ -1630,11 +1630,11 @@ static const struct dev_pm_ops kxcjk1013_pm_ops = {
};
static const struct i2c_device_id kxcjk1013_id[] = {
- { .name = "kxcjk1013", .driver_data = (kernel_ulong_t)&kxcjk1013_info },
- { .name = "kxcj91008", .driver_data = (kernel_ulong_t)&kxcj91008_info },
- { .name = "kxtj21009", .driver_data = (kernel_ulong_t)&kxtj21009_info },
- { .name = "kxtf9", .driver_data = (kernel_ulong_t)&kxtf9_info },
- { .name = "kx023-1025", .driver_data = (kernel_ulong_t)&kx0231025_info },
+ { .name = "kxcjk1013", .driver_data_ptr = &kxcjk1013_info },
+ { .name = "kxcj91008", .driver_data_ptr = &kxcj91008_info },
+ { .name = "kxtj21009", .driver_data_ptr = &kxtj21009_info },
+ { .name = "kxtf9", .driver_data_ptr = &kxtf9_info },
+ { .name = "kx023-1025", .driver_data_ptr = &kx0231025_info },
{ }
};
MODULE_DEVICE_TABLE(i2c, kxcjk1013_id);
that are an improvement for readability (again!) and it keeps some
properties of the pointers (here: being const) without having to pay
attention for that. (I didn't find a good example in sound/soc, so an
iio driver was used to demonstrate the gain.)
My additional motivation for this effort is CHERI[1]. This is a hardware
extension that uses 128 bit pointers but unsigned long is still 64 bit.
So with CHERI you cannot store pointers in unsigned long variables.
The first patch drops a few empty remove callbacks that I found while
working on patch #2. The second converts all hwmon drivers to use named
initializers.
Link: https://patch.msgid.link/cover.1778692164.git.u.kleine-koenig@baylibre.com
While being less compact, using named initializers allows to more easily
see which members of the structs are assigned which value without having
to lookup the declaration of the struct. And it's also more robust
against changes to the struct definition.
The mentioned robustness is relevant for a planned change to struct
i2c_device_id that replaces .driver_data by an anonymous union.
While touching all these arrays, unify indention and usage of commas.
This patch doesn't modify the compiled arrays, only their representation
in source form benefits. The former was confirmed with x86 and arm64
builds.
Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Link: https://patch.msgid.link/ae2ff4898eb340bd8bcafb7b75443eb4a0ce3e76.1778692164.git.u.kleine-koenig@baylibre.com
Signed-off-by: Mark Brown <broonie@kernel.org>
A remove callback that does nothing has the same semantic (apart from a
debug output) as no such callback at all as i2c_device_remove() just does:
if (driver->remove) {
dev_dbg(dev, "remove\n");
driver->remove(client);
}
Remove these useless callbacks.
While touching the driver structs, unify indention.
Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
Link: https://patch.msgid.link/3afd8230634dd68ac7c1885ee2b01da377349f89.1778692164.git.u.kleine-koenig@baylibre.com
Signed-off-by: Mark Brown <broonie@kernel.org>
The SPI controller API is asymmetric in that a controller is allocated
and registered in two step, while it is freed as part of deregistration.
[1]
This is especially unfortunate as any driver data is freed along with
the controller, something which has lead to use-after-free bugs during
deregistration when drivers tear down resources after deregistering the
controller (or tear down resources that may still be in use before
deregistering the controller in an attempt to work around the API).
To reduce the risk of such bugs being introduced a device managed
allocation interface was added, but this arguably made things even less
consistent as now whether the controller gets freed as part of
deregistration depends on how it was allocated. [2][3]
With most drivers converted to use managed allocation in preparation for
fixing the API, the remaining 16 drivers can be converted in one
tree-wide change. Ten of those drivers use the bitbang interface and can
be converted by simply removing the extra reference already taken by
spi_bitbang_start() (and updating the two bitbang drivers that use
managed allocation). [4]
Fix the API inconsistency by no longer dropping a reference when
deregistering non-devres allocated controllers.
[1] 68b892f1fd ("spi: document odd controller reference handling")
[2] 5e844cc37a ("spi: Introduce device-managed SPI controller allocation")
[3] 3f174274d2 ("spi: fix misleading controller deregistration kernel-doc")
[4] 702a4879ec ("spi: bitbang: Let spi_bitbang_start() take a reference to master")
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://patch.msgid.link/20260521073816.766596-1-johan@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
