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Document support for the CAN-FD Interface on the RZ/G3E (R9A09G047) SoC,
which supports up to six channels.
The CAN-FD module on RZ/G3E is very similar to the one on both R-Car V4H
and RZ/G2L, but differs in some hardware parameters:
* No external clock, but instead has ram clock.
* Support up to 6 channels.
* 20 interrupts.
Reviewed-by: "Rob Herring (Arm)" <robh@kernel.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://patch.msgid.link/20250417054320.14100-3-biju.das.jz@bp.renesas.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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RZ/G3E SoC has 20 interrupts, 2 resets and 6 channels that need more
branching with conditional schema. Simplify the conditional schema with
if statements rather than the complex if-else statements to prepare for
supporting RZ/G3E SoC.
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://patch.msgid.link/20250417054320.14100-2-biju.das.jz@bp.renesas.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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Bring in the netfs API documentation updates which had been in the
vfs-6.16.misc branch for most of this cycle. So don't needlessly rewrite
the vfs-6.16.misc by dropping it from that branch and moving it to
vfs-6.16.netfs. Simply merge vfs-6.16.misc into vfs-6.16.netfs.
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Add a driver for a series of SPMI-attached PMICs present on Apple devices
Reviewed-by: Neal Gompa <neal@gompa.dev>
Reviewed-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Signed-off-by: Hector Martin <marcan@marcan.st>
Co-developed-by: Sasha Finkelstein <fnkl.kernel@gmail.com>
Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>
Signed-off-by: Srinivas Kandagatla <srini@kernel.org>
Link: https://lore.kernel.org/r/20250509122452.11827-4-srini@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Add bindings for exposing SPMI registers of Apple PMICs as NVMEM cells
Reviewed-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>
Reviewed-by: "Rob Herring (Arm)" <robh@kernel.org>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Signed-off-by: Srinivas Kandagatla <srini@kernel.org>
Link: https://lore.kernel.org/r/20250509122452.11827-3-srini@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Board files are deprecated by DT, and the last user of
nvmem_add_cell_table() was removed by commit 2af4fcc0d3574482 ("ARM:
davinci: remove unused board support") in v6.3. Hence remove all
support for nvmem cell tables, and update the documentation.
Device drivers can still register a single cell using
nvmem_add_one_cell() (which was not documented before).
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Srinivas Kandagatla <srini@kernel.org>
Link: https://lore.kernel.org/r/20250509122452.11827-2-srini@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Commit 29be47fcd6a0 ("nvmem: zynqmp_nvmem: zynqmp_nvmem_probe cleanup")
changed the driver to expect the device pointer to be passed as the
"context", but in nvmem the context parameter comes from nvmem_config.priv
which is never set - Leading to null pointer exceptions when the device is
accessed.
Fixes: 29be47fcd6a0 ("nvmem: zynqmp_nvmem: zynqmp_nvmem_probe cleanup")
Cc: stable <stable@kernel.org>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Reviewed-by: Michal Simek <michal.simek@amd.com>
Tested-by: Michal Simek <michal.simek@amd.com>
Signed-off-by: Srinivas Kandagatla <srini@kernel.org>
Link: https://lore.kernel.org/r/20250509122407.11763-3-srini@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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The newly added crc checking leads to a link failure if CRC32
itself is disabled:
x86_64-linux-ld: vmlinux.o: in function `rmem_eyeq5_checksum':
rmem.c:(.text+0x52341b): undefined reference to `crc32_le_arch'
Fixes: 7e606c311f70 ("nvmem: rmem: add CRC validation for Mobileye EyeQ5 NVMEM")
Cc: stable <stable@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Srinivas Kandagatla <srini@kernel.org>
Link: https://lore.kernel.org/r/20250509122407.11763-2-srini@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Over last year, several patches for drivers/mux/ were not picked up,
even after multiple pings or resends, so mark the mux subsystem as odd
fixes to clarify actual status of lack of maintainers with dedicated
time and indicate that someone could help here.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20250501175303.144102-2-krzysztof.kozlowski@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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The active reference lifecycle provides the break/unbreak mechanism but
the active reference is not truly active after unbreak -- callers don't
use it afterwards but it's important for proper pairing of kn->active
counting. Assuming this mechanism is in place, the WARN check in
kernfs_should_drain_open_files() is too sensitive -- it may transiently
catch those (rightful) callers between
kernfs_unbreak_active_protection() and kernfs_put_active() as found out by Chen
Ridong:
kernfs_remove_by_name_ns kernfs_get_active // active=1
__kernfs_remove // active=0x80000002
kernfs_drain ...
wait_event
//waiting (active == 0x80000001)
kernfs_break_active_protection
// active = 0x80000001
// continue
kernfs_unbreak_active_protection
// active = 0x80000002
...
kernfs_should_drain_open_files
// warning occurs
kernfs_put_active
To avoid the false positives (mind panic_on_warn) remove the check altogether.
(This is meant as quick fix, I think active reference break/unbreak may be
simplified with larger rework.)
Fixes: bdb2fd7fc56e1 ("kernfs: Skip kernfs_drain_open_files() more aggressively")
Link: https://lore.kernel.org/r/kmmrseckjctb4gxcx2rdminrjnq2b4ipf7562nvfd432ld5v5m@2byj5eedkb2o/
Cc: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20250505121201.879823-1-mkoutny@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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I'm no longer able to perform this role since I left IBM.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/8734czh8yg.fsf@mpe.ellerman.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/jic23/iio into char-misc-next
Jonathan writes:
IIO: 2nd set of fixes for 6.15 (or 6.16 merge window)
Usual mixed bag.
adi,ad4851
- Avoid a buffer overrun due to bug in pointer arithmetic.
adi,ad7173
- Fix compiling if gpiolib is not enabled
adi,ad7606
- Fix raw reads for 18-bit chips by ensuring we mask out upper bits
as some SPI controllers do not do so for 18bit words.
- Fix wrong masking for register writes.
adi,ad7944
- Mask high bits for raw reads.
adi,axi-adc
- Add check on whether the busy flag has cleared before first access.
invensense,icm42600
- Fix the temperature offset to take scale into account.
nxp,fxls8962af
- Fix temperature to be in milli degrees Celsius not degrees.
- Fix sign of temperature channel.
* tag 'iio-fixes-for-6.15b' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/jic23/iio:
iio: accel: fxls8962af: Fix temperature scan element sign
iio: accel: fxls8962af: Fix temperature calculation
iio: adc: ad7944: mask high bits on direct read
iio: adc: ad4851: fix ad4858 chan pointer handling
iio: imu: inv_icm42600: Fix temperature calculation
iio: dac: adi-axi-dac: fix bus read
iio: adc: ad7606_spi: fix reg write value mask
iio: adc: ad7606: fix raw read for 18-bit chips
iio: adc: ad7173: fix compiling without gpiolib
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-Wflex-array-member-not-at-end was introduced in GCC-14, and we are
getting ready to enable it, globally.
Use the `DEFINE_RAW_FLEX()` helper for on-stack definitions of
a flexible structure where the size of the flexible-array member
is known at compile-time, and refactor the rest of the code,
accordingly.
So, with these changes, fix the following warnings:
drivers/w1/w1_netlink.c:198:31: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
drivers/w1/w1_netlink.c:219:31: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
Reviewed-by: Kees Cook <kees@kernel.org>
Signed-off-by: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/Z_RflBe5iDGTMFjV@kspp
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20250513105326.27385-2-krzysztof.kozlowski@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/krzk/linux into char-misc-next
Krzysztof writes:
Mux drivers for v6.16
Few cleanups and fixes for the mux drivers:
1. Simplify with spi_get_device_match_data().
2. Fix -Wunused-const-variable and -Wvoid-pointer-to-enum-cast warnings.
3. GPIO mux: add optional regulator for Lenovo T14s laptop headset.
4. MMIO mux: avoid using syscon's device_node_to_regmap(), due to
changes in the syscon code.
* tag 'mux-drv-6.16' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/krzk/linux:
mux: adgs1408: fix Wvoid-pointer-to-enum-cast warning
mux: gpio: add optional regulator support
dt-bindings: mux: add optional regulator binding to gpio mux
mux: mmio: Do not use syscon helper to build regmap
mux: adg792a: remove incorrect of_match_ptr annotation
mux: adgs1408: simplify with spi_get_device_match_data()
mux: mmio: Add missing word in error message
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ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/mani/mhi into char-misc-next
Manivannan writes:
MHI Host
========
- Fix conflict between MHI power up and SYSERR state transitions by issuing MHI
reset only if the device is in SYSERR state while in SBL/PBL EEs. The device
won't respond to reset if it is not in SYSERR state in SBL/PBL EEs.
- Remove redundant call to pci_assign_resource() since PCI core calls this API
internally.
- Add Telit FN920C04 modem which is based on Qcom SDX35 chipset.
* tag 'mhi-for-v6.16' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/mani/mhi:
bus: mhi: host: pci_generic: Add Telit FN920C04 modem support
bus: mhi: host: pci_generic: Remove redundant assign resource usage
bus: mhi: host: Fix conflict between power_up and SYSERR
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ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/mani/mhi into char-misc-next
Manivannan writes:
MHI Endpoint
============
- Increment the rd_offset after writing the buffer to avoid MHI host accessing
the incomplete/wrong buffer element.
* tag 'mhi-fixes-for-v6.15' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/mani/mhi:
bus: mhi: ep: Update read pointer only after buffer is written
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ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/fpga/linux-fpga into char-misc-next
Xu writes:
FPGA Manager changes for 6.16-rc1
- Peter hands over the maintain role of m10bmc-sec driver to Matthew.
- Qasim's change fix potential NULL pointer for fpga test.
All patches have been reviewed on the mailing list, and have been in the
last linux-next releases (as part of our for-next branch).
Signed-off-by: Xu Yilun <yilun.xu@intel.com>
* tag 'fpga-for-6.16-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/fpga/linux-fpga:
fpga: fix potential null pointer deref in fpga_mgr_test_img_load_sgt()
fpga: m10bmc-sec: change contact for secure update driver
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ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/wbg/counter into char-misc-next
William writes:
Counter updates for 6.16
An update to allow for larger count values in interrupt-cnt.
* tag 'counter-updates-for-6.16' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/wbg/counter:
counter: interrupt-cnt: Convert atomic_t -> atomic_long_t
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ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/wbg/counter into char-misc-next
William writes:
Counter fixes for 6.15
A fix to prevent a race condition when accessing the Count enable
component in interrupt-cnt.
* tag 'counter-fixes-for-6.15' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/wbg/counter:
counter: interrupt-cnt: Protect enable/disable OPs with mutex
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Fixes one small typo (`utilties` to `utilities`) in the documentation of
`MiscDevice::ioctl`.
Fixes: f893691e7426 ("rust: miscdevice: add base miscdevice abstraction")
Signed-off-by: Christian Schrefl <chrisi.schrefl@gmail.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250517-rust_miscdevice_fix_typo-v1-1-8c30a6237ba9@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Renesas R-Car V4H (r8a779g0) has PCIe controller, and it requires
specific firmware downloading. So, add a document about the firmware
how to get.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
[kwilczynski: commit log, refactor the document content and then add
this new file to a correct index under the top-level PCI documentation]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20250507100947.608875-1-yoshihiro.shimoda.uh@renesas.com
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Christian Brauner <brauner@kernel.org> says:
Coredumping currently supports two modes:
(1) Dumping directly into a file somewhere on the filesystem.
(2) Dumping into a pipe connected to a usermode helper process
spawned as a child of the system_unbound_wq or kthreadd.
For simplicity I'm mostly ignoring (1). There's probably still some
users of (1) out there but processing coredumps in this way can be
considered adventurous especially in the face of set*id binaries.
The most common option should be (2) by now. It works by allowing
userspace to put a string into /proc/sys/kernel/core_pattern like:
|/usr/lib/systemd/systemd-coredump %P %u %g %s %t %c %h
The "|" at the beginning indicates to the kernel that a pipe must be
used. The path following the pipe indicator is a path to a binary that
will be spawned as a usermode helper process. Any additional parameters
pass information about the task that is generating the coredump to the
binary that processes the coredump.
In the example core_pattern shown above systemd-coredump is spawned as a
usermode helper. There's various conceptual consequences of this
(non-exhaustive list):
- systemd-coredump is spawned with file descriptor number 0 (stdin)
connected to the read-end of the pipe. All other file descriptors are
closed. That specifically includes 1 (stdout) and 2 (stderr). This has
already caused bugs because userspace assumed that this cannot happen
(Whether or not this is a sane assumption is irrelevant.).
- systemd-coredump will be spawned as a child of system_unbound_wq. So
it is not a child of any userspace process and specifically not a
child of PID 1. It cannot be waited upon and is in a weird hybrid
upcall which are difficult for userspace to control correctly.
- systemd-coredump is spawned with full kernel privileges. This
necessitates all kinds of weird privilege dropping excercises in
userspace to make this safe.
- A new usermode helper has to be spawned for each crashing process.
This series adds a new mode:
(3) Dumping into an AF_UNIX socket.
Userspace can set /proc/sys/kernel/core_pattern to:
@/path/to/coredump.socket
The "@" at the beginning indicates to the kernel that an AF_UNIX
coredump socket will be used to process coredumps.
The coredump socket must be located in the initial mount namespace.
When a task coredumps it opens a client socket in the initial network
namespace and connects to the coredump socket.
- The coredump server should use SO_PEERPIDFD to get a stable handle on
the connected crashing task. The retrieved pidfd will provide a stable
reference even if the crashing task gets SIGKILLed while generating
the coredump.
- By setting core_pipe_limit non-zero userspace can guarantee that the
crashing task cannot be reaped behind it's back and thus process all
necessary information in /proc/<pid>. The SO_PEERPIDFD can be used to
detect whether /proc/<pid> still refers to the same process.
The core_pipe_limit isn't used to rate-limit connections to the
socket. This can simply be done via AF_UNIX socket directly.
- The pidfd for the crashing task will contain information how the task
coredumps. The PIDFD_GET_INFO ioctl gained a new flag
PIDFD_INFO_COREDUMP which can be used to retreive the coredump
information.
If the coredump gets a new coredump client connection the kernel
guarantees that PIDFD_INFO_COREDUMP information is available.
Currently the following information is provided in the new
@coredump_mask extension to struct pidfd_info:
* PIDFD_COREDUMPED is raised if the task did actually coredump.
* PIDFD_COREDUMP_SKIP is raised if the task skipped coredumping (e.g.,
undumpable).
* PIDFD_COREDUMP_USER is raised if this is a regular coredump and
doesn't need special care by the coredump server.
* PIDFD_COREDUMP_ROOT is raised if the generated coredump should be
treated as sensitive and the coredump server should restrict access
to the generated coredump to sufficiently privileged users.
- The coredump server should mark itself as non-dumpable.
- A container coredump server in a separate network namespace can simply
bind to another well-know address and systemd-coredump fowards
coredumps to the container.
- Coredumps could in the future also be handled via per-user/session
coredump servers that run only with that users privileges.
The coredump server listens on the coredump socket and accepts a
new coredump connection. It then retrieves SO_PEERPIDFD for the
client, inspects uid/gid and hands the accepted client to the users
own coredump handler which runs with the users privileges only
(It must of coure pay close attention to not forward crashing suid
binaries.).
The new coredump socket will allow userspace to not have to rely on
usermode helpers for processing coredumps and provides a safer way to
handle them instead of relying on super privileged coredumping helpers.
This will also be significantly more lightweight since no fork()+exec()
for the usermodehelper is required for each crashing process. The
coredump server in userspace can just keep a worker pool.
* patches from https://lore.kernel.org/20250516-work-coredump-socket-v8-0-664f3caf2516@kernel.org:
selftests/coredump: add tests for AF_UNIX coredumps
selftests/pidfd: add PIDFD_INFO_COREDUMP infrastructure
coredump: validate socket name as it is written
coredump: show supported coredump modes
pidfs, coredump: add PIDFD_INFO_COREDUMP
coredump: add coredump socket
coredump: reflow dump helpers a little
coredump: massage do_coredump()
coredump: massage format_corename()
Link: https://lore.kernel.org/20250516-work-coredump-socket-v8-0-664f3caf2516@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Add a simple test for generating coredumps via AF_UNIX sockets.
Link: https://lore.kernel.org/20250516-work-coredump-socket-v8-9-664f3caf2516@kernel.org
Acked-by: Luca Boccassi <luca.boccassi@gmail.com>
Reviewed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Add PIDFD_INFO_COREDUMP infrastructure so we can use it in tests.
Link: https://lore.kernel.org/20250516-work-coredump-socket-v8-8-664f3caf2516@kernel.org
Acked-by: Luca Boccassi <luca.boccassi@gmail.com>
Reviewed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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In contrast to other parameters written into
/proc/sys/kernel/core_pattern that never fail we can validate enabling
the new AF_UNIX support. This is obviously racy as hell but it's always
been that way.
Link: https://lore.kernel.org/20250516-work-coredump-socket-v8-7-664f3caf2516@kernel.org
Acked-by: Luca Boccassi <luca.boccassi@gmail.com>
Reviewed-by: Jann Horn <jannh@google.com>
Reviewed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Allow userspace to discover what coredump modes are supported.
Link: https://lore.kernel.org/20250516-work-coredump-socket-v8-6-664f3caf2516@kernel.org
Acked-by: Luca Boccassi <luca.boccassi@gmail.com>
Reviewed-by: Jann Horn <jannh@google.com>
Reviewed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Extend the PIDFD_INFO_COREDUMP ioctl() with the new PIDFD_INFO_COREDUMP
mask flag. This adds the @coredump_mask field to struct pidfd_info.
When a task coredumps the kernel will provide the following information
to userspace in @coredump_mask:
* PIDFD_COREDUMPED is raised if the task did actually coredump.
* PIDFD_COREDUMP_SKIP is raised if the task skipped coredumping (e.g.,
undumpable).
* PIDFD_COREDUMP_USER is raised if this is a regular coredump and
doesn't need special care by the coredump server.
* PIDFD_COREDUMP_ROOT is raised if the generated coredump should be
treated as sensitive and the coredump server should restrict to the
generated coredump to sufficiently privileged users.
The kernel guarantees that by the time the connection is made the all
PIDFD_INFO_COREDUMP info is available.
Link: https://lore.kernel.org/20250516-work-coredump-socket-v8-5-664f3caf2516@kernel.org
Acked-by: Luca Boccassi <luca.boccassi@gmail.com>
Reviewed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Reviewed-by: Jann Horn <jannh@google.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Coredumping currently supports two modes:
(1) Dumping directly into a file somewhere on the filesystem.
(2) Dumping into a pipe connected to a usermode helper process
spawned as a child of the system_unbound_wq or kthreadd.
For simplicity I'm mostly ignoring (1). There's probably still some
users of (1) out there but processing coredumps in this way can be
considered adventurous especially in the face of set*id binaries.
The most common option should be (2) by now. It works by allowing
userspace to put a string into /proc/sys/kernel/core_pattern like:
|/usr/lib/systemd/systemd-coredump %P %u %g %s %t %c %h
The "|" at the beginning indicates to the kernel that a pipe must be
used. The path following the pipe indicator is a path to a binary that
will be spawned as a usermode helper process. Any additional parameters
pass information about the task that is generating the coredump to the
binary that processes the coredump.
In the example core_pattern shown above systemd-coredump is spawned as a
usermode helper. There's various conceptual consequences of this
(non-exhaustive list):
- systemd-coredump is spawned with file descriptor number 0 (stdin)
connected to the read-end of the pipe. All other file descriptors are
closed. That specifically includes 1 (stdout) and 2 (stderr). This has
already caused bugs because userspace assumed that this cannot happen
(Whether or not this is a sane assumption is irrelevant.).
- systemd-coredump will be spawned as a child of system_unbound_wq. So
it is not a child of any userspace process and specifically not a
child of PID 1. It cannot be waited upon and is in a weird hybrid
upcall which are difficult for userspace to control correctly.
- systemd-coredump is spawned with full kernel privileges. This
necessitates all kinds of weird privilege dropping excercises in
userspace to make this safe.
- A new usermode helper has to be spawned for each crashing process.
This series adds a new mode:
(3) Dumping into an AF_UNIX socket.
Userspace can set /proc/sys/kernel/core_pattern to:
@/path/to/coredump.socket
The "@" at the beginning indicates to the kernel that an AF_UNIX
coredump socket will be used to process coredumps.
The coredump socket must be located in the initial mount namespace.
When a task coredumps it opens a client socket in the initial network
namespace and connects to the coredump socket.
- The coredump server uses SO_PEERPIDFD to get a stable handle on the
connected crashing task. The retrieved pidfd will provide a stable
reference even if the crashing task gets SIGKILLed while generating
the coredump.
- By setting core_pipe_limit non-zero userspace can guarantee that the
crashing task cannot be reaped behind it's back and thus process all
necessary information in /proc/<pid>. The SO_PEERPIDFD can be used to
detect whether /proc/<pid> still refers to the same process.
The core_pipe_limit isn't used to rate-limit connections to the
socket. This can simply be done via AF_UNIX sockets directly.
- The pidfd for the crashing task will grow new information how the task
coredumps.
- The coredump server should mark itself as non-dumpable.
- A container coredump server in a separate network namespace can simply
bind to another well-know address and systemd-coredump fowards
coredumps to the container.
- Coredumps could in the future also be handled via per-user/session
coredump servers that run only with that users privileges.
The coredump server listens on the coredump socket and accepts a
new coredump connection. It then retrieves SO_PEERPIDFD for the
client, inspects uid/gid and hands the accepted client to the users
own coredump handler which runs with the users privileges only
(It must of coure pay close attention to not forward crashing suid
binaries.).
The new coredump socket will allow userspace to not have to rely on
usermode helpers for processing coredumps and provides a safer way to
handle them instead of relying on super privileged coredumping helpers
that have and continue to cause significant CVEs.
This will also be significantly more lightweight since no fork()+exec()
for the usermodehelper is required for each crashing process. The
coredump server in userspace can e.g., just keep a worker pool.
Link: https://lore.kernel.org/20250516-work-coredump-socket-v8-4-664f3caf2516@kernel.org
Acked-by: Luca Boccassi <luca.boccassi@gmail.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Reviewed-by: Jann Horn <jannh@google.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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The throttle support has been added in the generic code. Remove
the driver-specific throttle support.
Besides the throttle, perf_event_overflow may return true because of
event_limit. It already does an inatomic event disable. The pmu->stop
is not required either.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250520181644.2673067-17-kan.liang@linux.intel.com
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The throttle support has been added in the generic code. Remove
the driver-specific throttle support.
Besides the throttle, perf_event_overflow may return true because of
event_limit. It already does an inatomic event disable. The pmu->stop
is not required either.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Max Filippov <jcmvbkbc@gmail.com>
Link: https://lore.kernel.org/r/20250520181644.2673067-16-kan.liang@linux.intel.com
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The throttle support has been added in the generic code. Remove
the driver-specific throttle support.
Besides the throttle, perf_event_overflow may return true because of
event_limit. It already does an inatomic event disable. The pmu->stop
is not required either.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250520181644.2673067-15-kan.liang@linux.intel.com
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The throttle support has been added in the generic code. Remove
the driver-specific throttle support.
Besides the throttle, perf_event_overflow may return true because of
event_limit. It already does an inatomic event disable. The pmu->stop
is not required either.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250520181644.2673067-14-kan.liang@linux.intel.com
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The throttle support has been added in the generic code. Remove
the driver-specific throttle support.
Besides the throttle, perf_event_overflow may return true because of
event_limit. It already does an inatomic event disable. The pmu->stop
is not required either.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20250520181644.2673067-13-kan.liang@linux.intel.com
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|
The throttle support has been added in the generic code. Remove
the driver-specific throttle support.
Besides the throttle, perf_event_overflow may return true because of
event_limit. It already does an inatomic event disable. The pmu->stop
is not required either.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Vineet Gupta <vgupta@kernel.org>
Link: https://lore.kernel.org/r/20250520181644.2673067-12-kan.liang@linux.intel.com
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|
The throttle support has been added in the generic code. Remove
the driver-specific throttle support.
Besides the throttle, perf_event_overflow may return true because of
event_limit. It already does an inatomic event disable. The pmu->stop
is not required either.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250520181644.2673067-11-kan.liang@linux.intel.com
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|
The throttle support has been added in the generic code. Remove
the driver-specific throttle support.
Besides the throttle, perf_event_overflow may return true because of
event_limit. It already does an inatomic event disable. The pmu->stop
is not required either.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250520181644.2673067-10-kan.liang@linux.intel.com
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|
The throttle support has been added in the generic code. Remove
the driver-specific throttle support.
Besides the throttle, perf_event_overflow may return true because of
event_limit. It already does an inatomic event disable. The pmu->stop
is not required either.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Leo Yan <leo.yan@arm.com>
Link: https://lore.kernel.org/r/20250520181644.2673067-9-kan.liang@linux.intel.com
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|
The throttle support has been added in the generic code. Remove
the driver-specific throttle support.
Besides the throttle, perf_event_overflow may return true because of
event_limit. It already does an inatomic event disable. The pmu->stop
is not required either.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Link: https://lore.kernel.org/r/20250520181644.2673067-8-kan.liang@linux.intel.com
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The throttle support has been added in the generic code. Remove
the driver-specific throttle support.
Besides the throttle, perf_event_overflow may return true because of
event_limit. It already does an inatomic event disable. The pmu->stop
is not required either.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250520181644.2673067-7-kan.liang@linux.intel.com
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|
The throttle support has been added in the generic code. Remove
the driver-specific throttle support.
Besides the throttle, perf_event_overflow may return true because of
event_limit. It already does an inatomic event disable. The pmu->stop
is not required either.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250520181644.2673067-6-kan.liang@linux.intel.com
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|
The throttle support has been added in the generic code. Remove
the driver-specific throttle support.
Besides the throttle, perf_event_overflow may return true because of
event_limit. It already does an inatomic event disable. The pmu->stop
is not required either.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com>
Link: https://lore.kernel.org/r/20250520181644.2673067-5-kan.liang@linux.intel.com
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|
The throttle support has been added in the generic code. Remove
the driver-specific throttle support.
Besides the throttle, perf_event_overflow may return true because of
event_limit. It already does an inatomic event disable. The pmu->stop
is not required either.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250520181644.2673067-4-kan.liang@linux.intel.com
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The PERF_RECORD_THROTTLE records are dumped for all throttled events.
It's not necessary for group events, which are throttled altogether.
Optimize it by only dump the throttle log for the leader.
The sample right after the THROTTLE record must be generated by the
actual target event. It is good enough for the perf tool to locate the
actual target event.
Suggested-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20250520181644.2673067-3-kan.liang@linux.intel.com
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The current throttle logic doesn't work well with a group, e.g., the
following sampling-read case.
$ perf record -e "{cycles,cycles}:S" ...
$ perf report -D | grep THROTTLE | tail -2
THROTTLE events: 426 ( 9.0%)
UNTHROTTLE events: 425 ( 9.0%)
$ perf report -D | grep PERF_RECORD_SAMPLE -a4 | tail -n 5
0 1020120874009167 0x74970 [0x68]: PERF_RECORD_SAMPLE(IP, 0x1):
... sample_read:
.... group nr 2
..... id 0000000000000327, value 000000000cbb993a, lost 0
..... id 0000000000000328, value 00000002211c26df, lost 0
The second cycles event has a much larger value than the first cycles
event in the same group.
The current throttle logic in the generic code only logs the THROTTLE
event. It relies on the specific driver implementation to disable
events. For all ARCHs, the implementation is similar. Only the event is
disabled, rather than the group.
The logic to disable the group should be generic for all ARCHs. Add the
logic in the generic code. The following patch will remove the buggy
driver-specific implementation.
The throttle only happens when an event is overflowed. Stop the entire
group when any event in the group triggers the throttle.
The MAX_INTERRUPTS is set to all throttle events.
The unthrottled could happen in 3 places.
- event/group sched. All events in the group are scheduled one by one.
All of them will be unthrottled eventually. Nothing needs to be
changed.
- The perf_adjust_freq_unthr_events for each tick. Needs to restart the
group altogether.
- The __perf_event_period(). The whole group needs to be restarted
altogether as well.
With the fix,
$ sudo perf report -D | grep PERF_RECORD_SAMPLE -a4 | tail -n 5
0 3573470770332 0x12f5f8 [0x70]: PERF_RECORD_SAMPLE(IP, 0x2):
... sample_read:
.... group nr 2
..... id 0000000000000a28, value 00000004fd3dfd8f, lost 0
..... id 0000000000000a29, value 00000004fd3dfd8f, lost 0
Suggested-by: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20250520181644.2673067-2-kan.liang@linux.intel.com
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There is a spelling mistake in a fail error message. Fix it.
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20250520080657.30726-1-colin.i.king@gmail.com
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The kerneldoc for futex_wait_setup() states it can return "0" or "<1".
This isn't true because the error case is "<0" not less than 1.
Document that <0 is returned on error. Drop the possible return values
and state possible reasons.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: André Almeida <andrealmeid@igalia.com>
Link: https://lore.kernel.org/r/20250517151455.1065363-6-bigeasy@linutronix.de
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The prctl.h ABI header was slightly updated during the development of
the interface. In particular the "immutable" parameter became a bit in
the option argument.
Synchronize prctl.h ABI header again and make use of the definition in
the testsuite and "perf bench futex".
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: André Almeida <andrealmeid@igalia.com>
Link: https://lore.kernel.org/r/20250517151455.1065363-5-bigeasy@linutronix.de
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There is no need for an explicit NULL pointer initialisation plus a
comment why it is okay. RCU_INIT_POINTER() can be used for NULL
initialisations and it is documented.
This has been build tested with gcc version 9.3.0 (Debian 9.3.0-22) on a
x86-64 defconfig.
Fixes: 094ac8cff7858 ("futex: Relax the rcu_assign_pointer() assignment of mm->futex_phash in futex_mm_init()")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250517151455.1065363-4-bigeasy@linutronix.de
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Use TAP output for easier automated testing.
Suggested-by: André Almeida <andrealmeid@igalia.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: André Almeida <andrealmeid@igalia.com>
Link: https://lore.kernel.org/r/20250517151455.1065363-3-bigeasy@linutronix.de
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Use TAP output for easier automated testing.
Suggested-by: André Almeida <andrealmeid@igalia.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: André Almeida <andrealmeid@igalia.com>
Link: https://lore.kernel.org/r/20250517151455.1065363-2-bigeasy@linutronix.de
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