kernel/Documentation, branch linux-5.10.y

fou: Don't allow 0 for FOU_ATTR_IPPROTO.

2026-02-06T15:40:04Z

[ Upstream commit 7a9bc9e3f42391e4c187e099263cf7a1c4b69ff5 ] fou_udp_recv() has the same problem mentioned in the previous patch. If FOU_ATTR_IPPROTO is set to 0, skb is not freed by fou_udp_recv() nor "resubmit"-ted in ip_protocol_deliver_rcu(). Let's forbid 0 for FOU_ATTR_IPPROTO. Fixes: 23461551c0062 ("fou: Support for foo-over-udp RX path") Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20260115172533.693652-4-kuniyu@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

netlink: add a proto specification for FOU

2026-02-06T15:40:03Z

[ Upstream commit 4eb77b4ecd3c5eaab83adf76e67e0a7ed2a24418 ] FOU has a reasonably modern Genetlink family. Add a spec. Acked-by: Stanislav Fomichev Signed-off-by: Jakub Kicinski Signed-off-by: Paolo Abeni Stable-dep-of: 7a9bc9e3f423 ("fou: Don't allow 0 for FOU_ATTR_IPPROTO.") Signed-off-by: Sasha Levin

fs_context: drop the unused lsm_flags member

2026-01-19T12:11:37Z

[ Upstream commit 4e04143c869c5b6d499fbd5083caa860d5c942c3 ] This isn't ever used by VFS now, and it couldn't even work. Any FS that uses the SECURITY_LSM_NATIVE_LABELS flag needs to also process the value returned back from the LSM, so it needs to do its security_sb_set_mnt_opts() call on its own anyway. Signed-off-by: Ondrej Mosnacek Signed-off-by: Christian Brauner (Microsoft) Stable-dep-of: 8675c69816e4 ("NFS: Automounted filesystems should inherit ro,noexec,nodev,sync flags") Signed-off-by: Sasha Levin

Documentation: process: Also mention Sasha Levin as stable tree maintainer

2026-01-19T12:11:24Z

commit ba2457109d5b47a90fe565b39524f7225fc23e60 upstream. Sasha has also maintaining stable branch in conjunction with Greg since cb5d21946d2a2f ("MAINTAINERS: Add Sasha as a stable branch maintainer"). Mention him in 2.Process.rst. Cc: stable@vger.kernel.org Signed-off-by: Bagas Sanjaya Reviewed-by: Randy Dunlap Acked-by: Greg Kroah-Hartman Signed-off-by: Jonathan Corbet Message-ID: <20251022034336.22839-1-bagasdotme@gmail.com> Signed-off-by: Greg Kroah-Hartman

dt-bindings: pinctrl: toshiba,visconti: Fix number of items in groups

2025-12-06T21:08:21Z

[ Upstream commit 316e361b5d2cdeb8d778983794a1c6eadcb26814 ] The "groups" property can hold multiple entries (e.g. toshiba/tmpv7708-rm-mbrc.dts file), so allow that by dropping incorrect type (pinmux-node.yaml schema already defines that as string-array) and adding constraints for items. This fixes dtbs_check warnings like: toshiba/tmpv7708-rm-mbrc.dtb: pinctrl@24190000 (toshiba,tmpv7708-pinctrl): pwm-pins:groups: ['pwm0_gpio16_grp', 'pwm1_gpio17_grp', 'pwm2_gpio18_grp', 'pwm3_gpio19_grp'] is too long Fixes: 1825c1fe0057 ("pinctrl: Add DT bindings for Toshiba Visconti TMPV7700 SoC") Cc: stable@vger.kernel.org Signed-off-by: Krzysztof Kozlowski Acked-by: Conor Dooley Signed-off-by: Linus Walleij [ adjusted $ref context ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

Makefile.compiler: replace cc-ifversion with compiler-specific macros

2025-12-06T21:08:21Z

commit 88b61e3bff93f99712718db785b4aa0c1165f35c upstream. cc-ifversion is GCC specific. Replace it with compiler specific variants. Update the users of cc-ifversion to use these new macros. Link: https://github.com/ClangBuiltLinux/linux/issues/350 Link: https://lore.kernel.org/llvm/CAGG=3QWSAUakO42kubrCap8fp-gm1ERJJAYXTnP1iHk_wrH=BQ@mail.gmail.com/ Suggested-by: Bill Wendling Reviewed-by: Nathan Chancellor Signed-off-by: Nick Desaulniers Signed-off-by: Masahiro Yamada [nathan: Backport to 5.10 and eliminate instances of cc-ifversion that did not exist upstream when this change was original created] Signed-off-by: Nathan Chancellor Signed-off-by: Greg Kroah-Hartman

PCI: Add sysfs attribute for device power state

2025-10-29T13:01:24Z

[ Upstream commit 80a129afb75cba8434fc5071bd6919172442315c ] While PCI power states D0-D3hot can be queried from user-space via lspci, D3cold cannot. lspci cannot provide an accurate value when the device is in D3cold as it has to restore the device to D0 before it can access its power state via the configuration space, leading to it reporting D0 or another on-state. Thus lspci cannot be used to diagnose power consumption issues for devices that can enter D3cold or to ensure that devices properly enter D3cold at all. Add a new sysfs device attribute for the PCI power state, showing the current power state as seen by the kernel. [bhelgaas: drop READ_ONCE(), see discussion at the link] Link: https://lore.kernel.org/r/20201102141520.831630-1-luzmaximilian@gmail.com Signed-off-by: Maximilian Luz Signed-off-by: Bjorn Helgaas Stable-dep-of: 48991e493507 ("PCI/sysfs: Ensure devices are powered for config reads") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

arm64: errata: Apply workarounds for Neoverse-V3AE

2025-10-29T13:01:23Z

commit 0c33aa1804d101c11ba1992504f17a42233f0e11 upstream. Neoverse-V3AE is also affected by erratum #3312417, as described in its Software Developer Errata Notice (SDEN) document: Neoverse V3AE (MP172) SDEN v9.0, erratum 3312417 https://developer.arm.com/documentation/SDEN-2615521/9-0/ Enable the workaround for Neoverse-V3AE, and document this. Signed-off-by: Mark Rutland Cc: James Morse Cc: Will Deacon Cc: Catalin Marinas Signed-off-by: Ryan Roberts Signed-off-by: Will Deacon [ Ryan: Trivial backport ] Signed-off-by: Ryan Roberts Signed-off-by: Greg Kroah-Hartman

fs: Add 'initramfs_options' to set initramfs mount options

2025-10-29T13:01:14Z

[ Upstream commit 278033a225e13ec21900f0a92b8351658f5377f2 ] When CONFIG_TMPFS is enabled, the initial root filesystem is a tmpfs. By default, a tmpfs mount is limited to using 50% of the available RAM for its content. This can be problematic in memory-constrained environments, particularly during a kdump capture. In a kdump scenario, the capture kernel boots with a limited amount of memory specified by the 'crashkernel' parameter. If the initramfs is large, it may fail to unpack into the tmpfs rootfs due to insufficient space. This is because to get X MB of usable space in tmpfs, 2*X MB of memory must be available for the mount. This leads to an OOM failure during the early boot process, preventing a successful crash dump. This patch introduces a new kernel command-line parameter, initramfs_options, which allows passing specific mount options directly to the rootfs when it is first mounted. This gives users control over the rootfs behavior. For example, a user can now specify initramfs_options=size=75% to allow the tmpfs to use up to 75% of the available memory. This can significantly reduce the memory pressure for kdump. Consider a practical example: To unpack a 48MB initramfs, the tmpfs needs 48MB of usable space. With the default 50% limit, this requires a memory pool of 96MB to be available for the tmpfs mount. The total memory requirement is therefore approximately: 16MB (vmlinuz) + 48MB (loaded initramfs) + 48MB (unpacked kernel) + 96MB (for tmpfs) + 12MB (runtime overhead) ≈ 220MB. By using initramfs_options=size=75%, the memory pool required for the 48MB tmpfs is reduced to 48MB / 0.75 = 64MB. This reduces the total memory requirement by 32MB (96MB - 64MB), allowing the kdump to succeed with a smaller crashkernel size, such as 192MB. An alternative approach of reusing the existing rootflags parameter was considered. However, a new, dedicated initramfs_options parameter was chosen to avoid altering the current behavior of rootflags (which applies to the final root filesystem) and to prevent any potential regressions. Also add documentation for the new kernel parameter "initramfs_options" This approach is inspired by prior discussions and patches on the topic. Ref: https://www.lightofdawn.org/blog/?viewDetailed=00128 Ref: https://landley.net/notes-2015.html#01-01-2015 Ref: https://lkml.org/lkml/2021/6/29/783 Ref: https://www.kernel.org/doc/html/latest/filesystems/ramfs-rootfs-initramfs.html#what-is-rootfs Signed-off-by: Lichen Liu Link: https://lore.kernel.org/20250815121459.3391223-1-lichliu@redhat.com Tested-by: Rob Landley Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin

Documentation: trace: historgram-design: Separate sched_waking histogram section heading and the following diagram

2025-10-29T13:01:06Z

[ Upstream commit 8c716e87ea33519920811338100d6d8a7fb32456 ] Section heading for sched_waking histogram is shown as normal paragraph instead due to codeblock marker for the following diagram being in the same line as the section underline. Separate them. Fixes: daceabf1b494 ("tracing/doc: Fix ascii-art in histogram-design.rst") Reviewed-by: Tom Zanussi Reviewed-by: Masami Hiramatsu (Google) Signed-off-by: Bagas Sanjaya Acked-by: Steven Rostedt (Google) Signed-off-by: Jonathan Corbet Message-ID: <20250916054202.582074-5-bagasdotme@gmail.com> Signed-off-by: Sasha Levin