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We no longer support any board files for DaVinci in mainline and so
struct da8xx_ohci_root_hub is no longer used. Remove it together with
all the code it's used for.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://patch.msgid.link/20251114-davinci-usb-v1-1-737380353a74@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Add a report_bug() variant where the bug_entry is already known. This
is useful when the exception instruction is not instantiated per-site.
But instead has a single instance. In such a case the bug_entry
address might be passed along in a known register or something.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251110115757.575795595@infradead.org
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Up to UEFI spec 2.9, the type byte of CPER struct for ARM processor
was defined simply as:
Type at byte offset 4:
- Cache error
- TLB Error
- Bus Error
- Micro-architectural Error
All other values are reserved
Yet, there was no information about how this would be encoded.
Spec 2.9A errata corrected it by defining:
- Bit 1 - Cache Error
- Bit 2 - TLB Error
- Bit 3 - Bus Error
- Bit 4 - Micro-architectural Error
All other values are reserved
That actually aligns with the values already defined on older
versions at N.2.4.1. Generic Processor Error Section.
Spec 2.10 also preserve the same encoding as 2.9A.
Adjust CPER and GHES handling code for both generic and ARM
processors to properly handle UEFI 2.9A and 2.10 encoding.
Link: https://uefi.org/specs/UEFI/2.10/Apx_N_Common_Platform_Error_Record.html#arm-processor-error-information
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
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Add a helper function to print a string with names associated
to each bit field.
A typical example is:
const char * const bits[] = {
"bit 3 name",
"bit 4 name",
"bit 5 name",
};
char str[120];
unsigned int bitmask = BIT(3) | BIT(5);
#define MASK GENMASK(5,3)
cper_bits_to_str(str, sizeof(str), FIELD_GET(MASK, bitmask),
bits, ARRAY_SIZE(bits));
The above code fills string "str" with "bit 3 name|bit 5 name".
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
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The ARM processor CPER record was added in UEFI v2.6 and remained
unchanged up to v2.10.
Yet, the original arm_event trace code added by
e9279e83ad1f ("trace, ras: add ARM processor error trace event")
is incomplete, as it only traces some fields of UAPI 2.6 table N.16, not
exporting any information from tables N.17 to N.29 of the record.
This is not enough for the user to be able to figure out what has
exactly happened or to take appropriate action.
According to the UEFI v2.9 specification chapter N2.4.4, the ARM
processor error section includes:
- several (ERR_INFO_NUM) ARM processor error information structures
(Tables N.17 to N.20);
- several (CONTEXT_INFO_NUM) ARM processor context information
structures (Tables N.21 to N.29);
- several vendor specific error information structures. The
size is given by Section Length minus the size of the other
fields.
In addition, it also exports two fields that are parsed by the GHES
driver when firmware reports it, e.g.:
- error severity
- CPU logical index
Report all of these information to userspace via a the ARM tracepoint so
that userspace can properly record the error and take decisions related
to CPU core isolation according to error severity and other info.
The updated ARM trace event now contains the following fields:
====================================== =============================
UEFI field on table N.16 ARM Processor trace fields
====================================== =============================
Validation handled when filling data for
affinity MPIDR and running
state.
ERR_INFO_NUM pei_len
CONTEXT_INFO_NUM ctx_len
Section Length indirectly reported by
pei_len, ctx_len and oem_len
Error affinity level affinity
MPIDR_EL1 mpidr
MIDR_EL1 midr
Running State running_state
PSCI State psci_state
Processor Error Information Structure pei_err - count at pei_len
Processor Context ctx_err- count at ctx_len
Vendor Specific Error Info oem - count at oem_len
====================================== =============================
It should be noted that decoding of tables N.17 to N.29, if needed, will
be handled in userspace. That gives more flexibility, as there won't be
any need to flood the kernel with micro-architecture specific error
decoding.
Also, decoding the other fields require a complex logic, and should be
done for each of the several values inside the record field. So, let
userspace daemons like rasdaemon decode them, parsing such tables and
having vendor-specific micro-architecture-specific decoders.
[mchehab: modified description, solved merge conflicts and fixed coding style]
Signed-off-by: Jason Tian <jason@os.amperecomputing.com>
Co-developed-by: Shengwei Luo <luoshengwei@huawei.com>
Signed-off-by: Shengwei Luo <luoshengwei@huawei.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Daniel Ferguson <danielf@os.amperecomputing.com> # rebased
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Tested-by: Shiju Jose <shiju.jose@huawei.com>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Fixes: e9279e83ad1f ("trace, ras: add ARM processor error trace event")
Link: https://uefi.org/specs/UEFI/2.10/Apx_N_Common_Platform_Error_Record.html#arm-processor-error-section
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
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[v9] vfio/pci: Allow MMIO regions to be exported through dma-buf
https://lore.kernel.org/all/20251120-dmabuf-vfio-v9-0-d7f71607f371@nvidia.com
Signed-off-by: Alex Williamson <alex@shazbot.org>
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Add support for exporting PCI device MMIO regions through dma-buf,
enabling safe sharing of non-struct page memory with controlled
lifetime management. This allows RDMA and other subsystems to import
dma-buf FDs and build them into memory regions for PCI P2P operations.
The implementation provides a revocable attachment mechanism using
dma-buf move operations. MMIO regions are normally pinned as BARs
don't change physical addresses, but access is revoked when the VFIO
device is closed or a PCI reset is issued. This ensures kernel
self-defense against potentially hostile userspace.
Currently VFIO can take MMIO regions from the device's BAR and map
them into a PFNMAP VMA with special PTEs. This mapping type ensures
the memory cannot be used with things like pin_user_pages(), hmm, and
so on. In practice only the user process CPU and KVM can safely make
use of these VMA. When VFIO shuts down these VMAs are cleaned by
unmap_mapping_range() to prevent any UAF of the MMIO beyond driver
unbind.
However, VFIO type 1 has an insecure behavior where it uses
follow_pfnmap_*() to fish a MMIO PFN out of a VMA and program it back
into the IOMMU. This has a long history of enabling P2P DMA inside
VMs, but has serious lifetime problems by allowing a UAF of the MMIO
after the VFIO driver has been unbound.
Introduce DMABUF as a new safe way to export a FD based handle for the
MMIO regions. This can be consumed by existing DMABUF importers like
RDMA or DRM without opening an UAF. A following series will add an
importer to iommufd to obsolete the type 1 code and allow safe
UAF-free MMIO P2P in VM cases.
DMABUF has a built in synchronous invalidation mechanism called
move_notify. VFIO keeps track of all drivers importing its MMIO and
can invoke a synchronous invalidation callback to tell the importing
drivers to DMA unmap and forget about the MMIO pfns. This process is
being called revoke. This synchronous invalidation fully prevents any
lifecycle problems. VFIO will do this before unbinding its driver
ensuring there is no UAF of the MMIO beyond the driver lifecycle.
Further, VFIO has additional behavior to block access to the MMIO
during things like Function Level Reset. This is because some poor
platforms may experience a MCE type crash when touching MMIO of a PCI
device that is undergoing a reset. Today this is done by using
unmap_mapping_range() on the VMAs. Extend that into the DMABUF world
and temporarily revoke the MMIO from the DMABUF importers during FLR
as well. This will more robustly prevent an errant P2P from possibly
upsetting the platform.
A DMABUF FD is a preferred handle for MMIO compared to using something
like a pgmap because:
- VFIO is supported, including its P2P feature, on archs that don't
support pgmap
- PCI devices have all sorts of BAR sizes, including ones smaller
than a section so a pgmap cannot always be created
- It is undesirable to waste a lot of memory for struct pages,
especially for a case like a GPU with ~100GB of BAR size
- We want a synchronous revoke semantic to support FLR with light
hardware requirements
Use the P2P subsystem to help generate the DMA mapping. This is a
significant upgrade over the abuse of dma_map_resource() that has
historically been used by DMABUF exporters. Experience with an OOT
version of this patch shows that real systems do need this. This
approach deals with all the P2P scenarios:
- Non-zero PCI bus_offset
- ACS flags routing traffic to the IOMMU
- ACS flags that bypass the IOMMU - though vfio noiommu is required
to hit this.
There will be further work to formalize the revoke semantic in
DMABUF. For now this acts like a move_notify dynamic exporter where
importer fault handling will get a failure when they attempt to map.
This means that only fully restartable fault capable importers can
import the VFIO DMABUFs. A future revoke semantic should open this up
to more HW as the HW only needs to invalidate, not handle restartable
faults.
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Acked-by: Ankit Agrawal <ankita@nvidia.com>
Link: https://lore.kernel.org/r/20251120-dmabuf-vfio-v9-10-d7f71607f371@nvidia.com
Signed-off-by: Alex Williamson <alex@shazbot.org>
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Remove the axi_blen array from struct stmmac_axi as we set this array,
and then immediately convert it ot the register value, never looking at
the array again. Thus, the array can be function local rather than part
of a run-time allocated long-lived struct.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/E1vLfLg-0000000FMbD-1vmh@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Move the call to stmmac_axi_blen_to_mask() out of the individual
MAC version drivers into the main code in stmmac_init_dma_engine(),
passing the resulting value through a new member, axi_blen_regval,
in the struct stmmac_axi structure.
There is now no need for stmmac_axi_blen_to_dma_mask() to use
u32p_replace_bits(), so use FIELD_PREP() instead.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/E1vLfLW-0000000FMb1-0zKV@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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As struct plat_stmmacenet_data is not platform_device specific, pass
a struct device into the init() and exit() methods to allow them to
become independent of the underlying device.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Acked-by: Chen-Yu Tsai <wens@kernel.org>
Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/E1vLf2U-0000000FMN2-0SLg@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Linux 6.18-rc6
Backmerge in order to merge msm next
Signed-off-by: Dave Airlie <airlied@redhat.com>
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Add missing kernel-doc documentation for the cfi_stubs and owner
fields in struct bpf_struct_ops to fix the following warnings:
Warning: include/linux/bpf.h:1931 struct member 'cfi_stubs' not
described in 'bpf_struct_ops'
Warning: include/linux/bpf.h:1931 struct member 'owner' not
described in 'bpf_struct_ops'
The cfi_stubs field was added in commit 2cd3e3772e41 ("x86/cfi,bpf:
Fix bpf_struct_ops CFI") to provide CFI stub functions for trampolines,
and the owner field is used for module reference counting.
Signed-off-by: Nirbhay Sharma <nirbhay.lkd@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20251120204620.59571-2-nirbhay.lkd@gmail.com
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These methods only exist when INLINE_COPY_FROM_USER is disabled, so update
the header file to reflect that.
This fixes the following error on builds that enable both RUST and
INLINE_COPY_FROM_USER.
ERROR: modpost: "_copy_from_user" [samples/rust/rust_misc_device.ko] undefined!
ERROR: modpost: "_copy_to_user" [samples/rust/rust_misc_device.ko] undefined!
This error is triggered because when a method is available both as a
rust_helper_* and normal method, Rust will call the normal method.
[akpm@linux-foundation.org: s/INLINE_COPY_FROM_USER/INLINE_COPY_TO_USER/, per Alice]
Link: https://lkml.kernel.org/r/20251118173250.2821388-1-aliceryhl@google.com
Fixes: d99dc586ca7c ("uaccess: decouple INLINE_COPY_FROM_USER and CONFIG_RUST")
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Andreas Hindborg <a.hindborg@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Björn Roy Baron <bjorn3_gh@protonmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Gary Guo <gary@garyguo.net>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Trevor Gross <tmgross@umich.edu>
Cc: Yury Norov (NVIDIA) <yury.norov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series " lib/base64: add generic encoder/decoder, migrate users", v5.
This series introduces a generic Base64 encoder/decoder to the kernel
library, eliminating duplicated implementations and delivering significant
performance improvements.
The Base64 API has been extended to support multiple variants (Standard,
URL-safe, and IMAP) as defined in RFC 4648 and RFC 3501. The API now
takes a variant parameter and an option to control padding. As part of
this series, users are migrated to the new interface while preserving
their specific formats: fscrypt now uses BASE64_URLSAFE, Ceph uses
BASE64_IMAP, and NVMe is updated to BASE64_STD.
On the encoder side, the implementation processes input in 3-byte blocks,
mapping 24 bits directly to 4 output symbols. This avoids bit-by-bit
streaming and reduces loop overhead, achieving about a 2.7x speedup
compared to previous implementations.
On the decoder side, replace strchr() lookups with per-variant reverse
tables and process input in 4-character groups. Each group is mapped to
numeric values and combined into 3 bytes. Padded and unpadded forms are
validated explicitly, rejecting invalid '=' usage and enforcing tail
rules. This improves throughput by ~43-52x.
This patch (of 6):
Extend the base64 API to support multiple variants (standard, URL-safe,
and IMAP) as defined in RFC 4648 and RFC 3501. The API now takes a
variant parameter and an option to control padding. Update NVMe auth code
to use the new interface with BASE64_STD.
Link: https://lkml.kernel.org/r/20251114055829.87814-1-409411716@gms.tku.edu.tw
Link: https://lkml.kernel.org/r/20251114060045.88792-1-409411716@gms.tku.edu.tw
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Co-developed-by: Guan-Chun Wu <409411716@gms.tku.edu.tw>
Signed-off-by: Guan-Chun Wu <409411716@gms.tku.edu.tw>
Reviewed-by: David Laight <david.laight.linux@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: "Theodore Y. Ts'o" <tytso@mit.edu>
Cc: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com>
Cc: Xiubo Li <xiubli@redhat.com>
Cc: Yu-Sheng Huang <home7438072@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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For c code:
```c
extern int xx;
void test(void)
{
if (WARN_ONCE(xx, "x"))
__asm__ volatile ("nop":::);
}
```
Clang will generate the following assembly code:
```assemble
test:
movl xx(%rip), %eax // Assume xx == 0 (likely case)
testl %eax, %eax // judge once
je .LBB0_3 // jump to .LBB0_3
testb $1, test.__already_done(%rip)
je .LBB0_2
.LBB0_3:
testl %eax, %eax // judge again
je .LBB0_5 // jump to .LBB0_5
.LBB0_4:
nop
.LBB0_5:
retq
// omit
```
In the above code, `xx == 0` should be a likely case, but in this case,
xx has been judged twice.
Test info:
1. kernel source:
linux-next
commit 9c0826a5d9aa4d52206d ("Add linux-next specific files for 20251107")
2. compiler:
clang: Debian clang version 21.1.4 (8) with
Debian LLD 21.1.4 (compatible with GNU linkers)
3. config:
base on default x86_64_defconfig, and setting:
CONFIG_MITIGATION_RETHUNK=n
CONFIG_STACKPROTECTOR=n
Add unlikely to __ret_cond to help the compiler optimize correctly.
[akpm@linux-foundation.org: undo whitespace changes]
Link: https://lkml.kernel.org/r/20251109083715.24495-1-qq570070308@gmail.com
Signed-off-by: Xie Yuanbin <qq570070308@gmail.com>
Cc: Bill Wendling <morbo@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Maninder Singh <maninder1.s@samsung.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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- amend the kernel-doc so the description is decoupled from the
parameter descriptions.
- add a note to explain behaviour for the signed types when supplied
value is the minimum (e.g., INT_MIN for int type).
Link: https://lkml.kernel.org/r/20251106152051.2361551-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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gcc generates horrid code for both ((u64)u32_a * u32_b) and (u64_a +
u32_b). As well as the extra instructions it can generate a lot of spills
to stack (including spills of constant zeros and even multiplies by
constant zero).
mul_u32_u32() already exists to optimise the multiply. Add a similar
add_u64_32() for the addition. Disable both for clang - it generates
better code without them.
Move the 64x64 => 128 multiply into a static inline helper function for
code clarity. No need for the a/b_hi/lo variables, the implicit casts on
the function calls do the work for us. Should have minimal effect on the
generated code.
Use mul_u32_u32() and add_u64_u32() in the 64x64 => 128 multiply in
mul_u64_add_u64_div_u64().
Link: https://lkml.kernel.org/r/20251105201035.64043-8-david.laight.linux@gmail.com
Signed-off-by: David Laight <david.laight.linux@gmail.com>
Reviewed-by: Nicolas Pitre <npitre@baylibre.com>
Cc: Biju Das <biju.das.jz@bp.renesas.com>
Cc: Borislav Betkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Li RongQing <lirongqing@baidu.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The existing mul_u64_u64_div_u64() rounds down, a 'rounding up' variant
needs 'divisor - 1' adding in between the multiply and divide so cannot
easily be done by a caller.
Add mul_u64_add_u64_div_u64(a, b, c, d) that calculates (a * b + c)/d and
implement the 'round down' and 'round up' using it.
Update the x86-64 asm to optimise for 'c' being a constant zero.
Add kerndoc definitions for all three functions.
Link: https://lkml.kernel.org/r/20251105201035.64043-5-david.laight.linux@gmail.com
Signed-off-by: David Laight <david.laight.linux@gmail.com>
Reviewed-by: Nicolas Pitre <npitre@baylibre.com>
Cc: Biju Das <biju.das.jz@bp.renesas.com>
Cc: Borislav Betkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Li RongQing <lirongqing@baidu.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The added documentation to u64_to_user_ptr() misspelled the function name.
Fix it.
Link: https://lkml.kernel.org/r/20251104183834.1046584-1-andriy.shevchenko@linux.intel.com
Fixes: 029c896c4105 ("kernel.h: move PTR_IF() and u64_to_user_ptr() to util_macros.h")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Alexandru Ardelean <aardelean@baylibre.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Align constant definition names with parameters to make it easier to map.
It's also better to maintain and extend the names while keeping their
uniqueness.
Link: https://lkml.kernel.org/r/20251030132007.3742368-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Feng Tang <feng.tang@linux.alibaba.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "make VM_SOFTDIRTY a sticky VMA flag", v2.
Currently we set VM_SOFTDIRTY when a new mapping is set up (whether by
establishing a new VMA, or via merge) as implemented in __mmap_complete()
and do_brk_flags().
However, when performing a merge of existing mappings such as when
performing mprotect(), we may lose the VM_SOFTDIRTY flag.
Now we have the concept of making VMA flags 'sticky', that is that they
both don't prevent merge and, importantly, are propagated to merged VMAs,
this seems a sensible alternative to the existing special-casing of
VM_SOFTDIRTY.
We additionally add a self-test that demonstrates that this logic behaves
as expected.
This patch (of 2):
Currently we set VM_SOFTDIRTY when a new mapping is set up (whether by
establishing a new VMA, or via merge) as implemented in __mmap_complete()
and do_brk_flags().
However, when performing a merge of existing mappings such as when
performing mprotect(), we may lose the VM_SOFTDIRTY flag.
This is because currently we simply ignore VM_SOFTDIRTY for the purposes
of merge, so one VMA may possess the flag and another not, and whichever
happens to be the target VMA will be the one upon which the merge is
performed which may or may not have VM_SOFTDIRTY set.
Now we have the concept of 'sticky' VMA flags, let's make VM_SOFTDIRTY one
which solves this issue.
Additionally update VMA userland tests to propagate changes.
[akpm@linux-foundation.org: update comments, per Lorenzo]
Link: https://lkml.kernel.org/r/0019e0b8-ee1e-4359-b5ee-94225cbe5588@lucifer.local
Link: https://lkml.kernel.org/r/cover.1763399675.git.lorenzo.stoakes@oracle.com
Link: https://lkml.kernel.org/r/955478b5170715c895d1ef3b7f68e0cd77f76868.1763399675.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Acked-by: Andrey Vagin <avagin@gmail.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Jann Horn <jannh@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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DAMOS filters that are handled by the ops layer are linked to
damos->ops_filters. Owing to the ops_ prefix on the name, it is easy to
understand it is for ops layer handled filters. The other types of
filters, which are handled by the core layer, are linked to
damos->filters. Because of the name, it is easy to confuse the list is
there for not only core layer handled ones but all filters. Avoid such
confusions by renaming the field to core_filters.
Link: https://lkml.kernel.org/r/20251112154114.66053-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Bill Wendling <morbo@google.com>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Gow <davidgow@google.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "mm/damon: misc cleanups".
Yet another batch of misc cleanups and refactoring for DAMON code, tests,
and documents.
First two patches (1and 2) rename DAMOS core filters related code for
readability.
Three following patches (3-5) refactor page table walk callback functions
in DAMON, as suggested by Hugh and David, and I promised.
Next two patches (6 and 7) refactor DAMON core layer kunit test and sysfs
interface selftest to be simple and deduplicated.
Final two patches (8 and 9) fix up sphinx and grammatical errors on
documents.
This patch (of 9):
DAMOS filters handled by the core layer are called core filters, while
those handled by the ops layer are called ops filters. They share the
same type but are managed in different places since core filters are
evaluated before the ops filters. They also have different helper
functions that depend on their managed places.
The helper functions for ops filters have '_ops_' keyword on their name,
so it is easy to know they are for ops filters. Meanwhile, the helper
functions for core filters are not having the 'core' keyword on their
name. This makes it easy to be mistakenly used for ops filters. Actually
there was such a bug.
To avoid future mistakes from similar confusions, rename DAMOS core
filters helper functions to have a keyword 'core' on their names.
Link: https://lkml.kernel.org/r/20251112154114.66053-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20251112154114.66053-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Bill Wendling <morbo@google.com>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Gow <davidgow@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "vma_start_write_killable"", v2.
When we added the VMA lock, we made a major oversight in not adding a
killable variant. That can run us into trouble where a thread takes the
VMA lock for read (eg handling a page fault) and then goes out to lunch
for an hour (eg doing reclaim). Another thread tries to modify the VMA,
taking the mmap_lock for write, then attempts to lock the VMA for write.
That blocks on the first thread, and ensures that every other page fault
now tries to take the mmap_lock for read. Because everything's in an
uninterruptible sleep, we can't kill the task, which makes me angry.
This patchset just adds vma_start_write_killable() and converts one caller
to use it. Most users are somewhat tricky to convert, so expect follow-up
individual patches per call-site which need careful analysis to make sure
we've done proper cleanup.
This patch (of 2):
The vma can be held read-locked for a substantial period of time, eg if
memory allocation needs to go into reclaim. It's useful to be able to
send fatal signals to threads which are waiting for the write lock.
Link: https://lkml.kernel.org/r/20251110203204.1454057-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20251110203204.1454057-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Chris Li <chriscli@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Currently kernel dumps memory state on oom and allocation failures. One
of the question usually raised on those dumps is why the kernel has not
reclaimed the reclaimable memory instead of triggering oom. One potential
reason is the usage of memory protection provided by memcg. So, let's
also dump the memory protected by the memcg in such reports to ease the
debugging.
Link: https://lkml.kernel.org/r/20251107234041.3632644-1-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Gather all the VMA flags whose presence implies that page tables must be
copied on fork into a single bitmap - VM_COPY_ON_FORK - and use this
rather than specifying individual flags in vma_needs_copy().
We also add VM_MAYBE_GUARD to this list, as it being set on a VMA implies
that there may be metadata contained in the page tables (that is - guard
markers) which would will not and cannot be propagated upon fork.
This was already being done manually previously in vma_needs_copy(), but
this makes it very explicit, alongside VM_PFNMAP, VM_MIXEDMAP and
VM_UFFD_WP all of which imply the same.
Note that VM_STICKY flags ought generally to be marked VM_COPY_ON_FORK too
- because equally a flag being VM_STICKY indicates that the VMA contains
metadat that is not propagated by being faulted in - i.e. that the VMA
metadata does not fully describe the VMA alone, and thus we must propagate
whatever metadata there is on a fork.
However, for maximum flexibility, we do not make this necessarily the case
here.
Link: https://lkml.kernel.org/r/5d41b24e7bc622cda0af92b6d558d7f4c0d1bc8c.1763460113.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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It is useful to be able to designate that certain flags are 'sticky', that
is, if two VMAs are merged one with a flag of this nature and one without,
the merged VMA sets this flag.
As a result we ignore these flags for the purposes of determining VMA flag
differences between VMAs being considered for merge.
This patch therefore updates the VMA merge logic to perform this action,
with flags possessing this property being described in the VM_STICKY
bitmap.
Those flags which ought to be ignored for the purposes of VMA merge are
described in the VM_IGNORE_MERGE bitmap, which the VMA merge logic is also
updated to use.
As part of this change we place VM_SOFTDIRTY in VM_IGNORE_MERGE as it
already had this behaviour, alongside VM_STICKY as sticky flags by
implication must not disallow merge.
Ultimately it seems that we should make VM_SOFTDIRTY a sticky flag in its
own right, but this change is out of scope for this series.
The only sticky flag designated as such is VM_MAYBE_GUARD, so as a result
of this change, once the VMA flag is set upon guard region installation,
VMAs with guard ranges will now not have their merge behaviour impacted as
a result and can be freely merged with other VMAs without VM_MAYBE_GUARD
set.
Also update the comments for vma_modify_flags() to directly reference
sticky flags now we have established the concept.
We also update the VMA userland tests to account for the changes.
Link: https://lkml.kernel.org/r/22ad5269f7669d62afb42ce0c79bad70b994c58d.1763460113.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand (Red Hat) <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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This patch adds the ability to atomically set VMA flags with only the mmap
read/VMA read lock held.
As this could be hugely problematic for VMA flags in general given that
all other accesses are non-atomic and serialised by the mmap/VMA locks, we
implement this with a strict allow-list - that is, only designated flags
are allowed to do this.
We make VM_MAYBE_GUARD one of these flags.
Link: https://lkml.kernel.org/r/97e57abed09f2663077ed7a36fb8206e243171a9.1763460113.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "introduce VM_MAYBE_GUARD and make it sticky", v4.
Currently, guard regions are not visible to users except through
/proc/$pid/pagemap, with no explicit visibility at the VMA level.
This makes the feature less useful, as it isn't entirely apparent which
VMAs may have these entries present, especially when performing actions
which walk through memory regions such as those performed by CRIU.
This series addresses this issue by introducing the VM_MAYBE_GUARD flag
which fulfils this role, updating the smaps logic to display an entry for
these.
The semantics of this flag are that a guard region MAY be present if set
(we cannot be sure, as we can't efficiently track whether an
MADV_GUARD_REMOVE finally removes all the guard regions in a VMA) - but if
not set the VMA definitely does NOT have any guard regions present.
It's problematic to establish this flag without further action, because
that means that VMAs with guard regions in them become non-mergeable with
adjacent VMAs for no especially good reason.
To work around this, this series also introduces the concept of 'sticky'
VMA flags - that is flags which:
a. if set in one VMA and not in another still permit those VMAs to be
merged (if otherwise compatible).
b. When they are merged, the resultant VMA must have the flag set.
The VMA logic is updated to propagate these flags correctly.
Additionally, VM_MAYBE_GUARD being an explicit VMA flag allows us to solve
an issue with file-backed guard regions - previously these established an
anon_vma object for file-backed mappings solely to have vma_needs_copy()
correctly propagate guard region mappings to child processes.
We introduce a new flag alias VM_COPY_ON_FORK (which currently only
specifies VM_MAYBE_GUARD) and update vma_needs_copy() to check explicitly
for this flag and to copy page tables if it is present, which resolves
this issue.
Additionally, we add the ability for allow-listed VMA flags to be
atomically writable with only mmap/VMA read locks held.
The only flag we allow so far is VM_MAYBE_GUARD, which we carefully ensure
does not cause any races by being allowed to do so.
This allows us to maintain guard region installation as a read-locked
operation and not endure the overhead of obtaining a write lock here.
Finally we introduce extensive VMA userland tests to assert that the
sticky VMA logic behaves correctly as well as guard region self tests to
assert that smaps visibility is correctly implemented.
This patch (of 9):
Currently, if a user needs to determine if guard regions are present in a
range, they have to scan all VMAs (or have knowledge of which ones might
have guard regions).
Since commit 8e2f2aeb8b48 ("fs/proc/task_mmu: add guard region bit to
pagemap") and the related commit a516403787e0 ("fs/proc: extend the
PAGEMAP_SCAN ioctl to report guard regions"), users can use either
/proc/$pid/pagemap or the PAGEMAP_SCAN functionality to perform this
operation at a virtual address level.
This is not ideal, and it gives no visibility at a /proc/$pid/smaps level
that guard regions exist in ranges.
This patch remedies the situation by establishing a new VMA flag,
VM_MAYBE_GUARD, to indicate that a VMA may contain guard regions (it is
uncertain because we cannot reasonably determine whether a
MADV_GUARD_REMOVE call has removed all of the guard regions in a VMA, and
additionally VMAs may change across merge/split).
We utilise 0x800 for this flag which makes it available to 32-bit
architectures also, a flag that was previously used by VM_DENYWRITE, which
was removed in commit 8d0920bde5eb ("mm: remove VM_DENYWRITE") and hasn't
bee reused yet.
We also update the smaps logic and documentation to identify these VMAs.
Another major use of this functionality is that we can use it to identify
that we ought to copy page tables on fork.
We do not actually implement usage of this flag in mm/madvise.c yet as we
need to allow some VMA flags to be applied atomically under mmap/VMA read
lock in order to avoid the need to acquire a write lock for this purpose.
Link: https://lkml.kernel.org/r/cover.1763460113.git.lorenzo.stoakes@oracle.com
Link: https://lkml.kernel.org/r/cf8ef821eba29b6c5b5e138fffe95d6dcabdedb9.1763460113.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Kill mm_wr_locked since commit f8e97613fed2 ("mm: convert VM_PFNMAP
tracking to pfnmap_track() + pfnmap_untrack()") remove the user.
Link: https://lkml.kernel.org/r/20251104085709.2688433-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Since commit 9254c8ae9b81 ("nfsd: disallow file locking and delegations
for NFSv4 reexport"), file locking when reexporting an NFS mount via
NFSv4 is expressly prohibited by nfsd. Do the same in lockd:
Add a new nlmsvc_file_cannot_lock() helper that will test whether file
locking is allowed for a given file, and return nlm_lck_denied_nolocks
if it isn't.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Tested-by: Olga Kornievskaia <okorniev@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
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set_tsk_need_resched(current) requires set_preempt_need_resched(current) to
work correctly outside of the scheduler.
Provide set_need_resched_current() which wraps this correctly and replace
all the open coded instances.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://patch.msgid.link/20251116174750.665769842@linutronix.de
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The buf_nr_pages field in io_buffer_list was previously used to
determine whether the buffer list uses ring-provided buffers or classic
provided buffers. This is now determined by checking the IOBL_BUF_RING
flag.
Remove the buf_nr_pages field and update related comments.
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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The timer migration mechanism allows active CPUs to pull timers from
idle ones to improve the overall idle time. This is however undesired
when CPU intensive workloads run on isolated cores, as the algorithm
would move the timers from housekeeping to isolated cores, negatively
affecting the isolation.
Exclude isolated cores from the timer migr |
