linux/Documentation/admin-guide/sysctl, branch master

vsock: document write-once behavior of the child_ns_mode sysctl

2026-02-26T10:10:03Z

Update the vsock child_ns_mode documentation to include the new write-once semantics of setting child_ns_mode. The semantics are implemented in a preceding patch in this series. Signed-off-by: Bobby Eshleman Reviewed-by: Stefano Garzarella Link: https://patch.msgid.link/20260223-vsock-ns-write-once-v3-3-c0cde6959923@meta.com Signed-off-by: Paolo Abeni

Merge tag 'net-7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2026-02-19T18:39:08Z

Pull networking fixes from Jakub Kicinski: "Including fixes from Netfilter. Current release - new code bugs: - net: fix backlog_unlock_irq_restore() vs CONFIG_PREEMPT_RT - eth: mlx5e: XSK, Fix unintended ICOSQ change - phy_port: correctly recompute the port's linkmodes - vsock: prevent child netns mode switch from local to global - couple of kconfig fixes for new symbols Previous releases - regressions: - nfc: nci: fix false-positive parameter validation for packet data - net: do not delay zero-copy skbs in skb_attempt_defer_free() Previous releases - always broken: - mctp: ensure our nlmsg responses to user space are zero-initialised - ipv6: ioam: fix heap buffer overflow in __ioam6_fill_trace_data() - fixes for ICMP rate limiting Misc: - intel: fix PCI device ID conflict between i40e and ipw2200" * tag 'net-7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (85 commits) net: nfc: nci: Fix parameter validation for packet data net/mlx5e: Use unsigned for mlx5e_get_max_num_channels net/mlx5e: Fix deadlocks between devlink and netdev instance locks net/mlx5e: MACsec, add ASO poll loop in macsec_aso_set_arm_event net/mlx5: Fix misidentification of write combining CQE during poll loop net/mlx5e: Fix misidentification of ASO CQE during poll loop net/mlx5: Fix multiport device check over light SFs bonding: alb: fix UAF in rlb_arp_recv during bond up/down bnge: fix reserving resources from FW eth: fbnic: Advertise supported XDP features. rds: tcp: fix uninit-value in __inet_bind net/rds: Fix NULL pointer dereference in rds_tcp_accept_one octeontx2-af: Fix default entries mcam entry action net/mlx5e: XSK, Fix unintended ICOSQ change ipv6: icmp: icmpv6_xrlim_allow() optimization if net.ipv6.icmp.ratelimit is zero ipv4: icmp: icmpv4_xrlim_allow() optimization if net.ipv4.icmp_ratelimit is zero ipv6: icmp: remove obsolete code in icmpv6_xrlim_allow() inet: move icmp_global_{credit,stamp} to a separate cache line icmp: prevent possible overflow in icmp_global_allow() selftests/net: packetdrill: add ipv4-mapped-ipv6 tests ...

vsock: document namespace mode sysctls

2026-02-18T01:20:21Z

Add documentation for the vsock per-namespace sysctls (`ns_mode` and `child_ns_mode`) to Documentation/admin-guide/sysctl/net.rst. These sysctls were introduced by commit eafb64f40ca4 ("vsock: add netns to vsock core"). Document the two namespace modes (`global` and `local`), the inheritance behavior of `child_ns_mode`, and the restriction preventing local namespaces from setting `child_ns_mode` to `global`. Signed-off-by: Stefano Garzarella Tested-by: Randy Dunlap Acked-by: Randy Dunlap Link: https://patch.msgid.link/20260216163147.236844-1-sgarzare@redhat.com Signed-off-by: Jakub Kicinski

Merge tag 'mm-stable-2026-02-11-19-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2026-02-12T19:32:37Z

Pull MM updates from Andrew Morton: - "powerpc/64s: do not re-activate batched TLB flush" makes arch_{enter|leave}_lazy_mmu_mode() nest properly (Alexander Gordeev) It adds a generic enter/leave layer and switches architectures to use it. Various hacks were removed in the process. - "zram: introduce compressed data writeback" implements data compression for zram writeback (Richard Chang and Sergey Senozhatsky) - "mm: folio_zero_user: clear page ranges" adds clearing of contiguous page ranges for hugepages. Large improvements during demand faulting are demonstrated (David Hildenbrand) - "memcg cleanups" tidies up some memcg code (Chen Ridong) - "mm/damon: introduce {,max_}nr_snapshots and tracepoint for damos stats" improves DAMOS stat's provided information, deterministic control, and readability (SeongJae Park) - "selftests/mm: hugetlb cgroup charging: robustness fixes" fixes a few issues in the hugetlb cgroup charging selftests (Li Wang) - "Fix va_high_addr_switch.sh test failure - again" addresses several issues in the va_high_addr_switch test (Chunyu Hu) - "mm/damon/tests/core-kunit: extend existing test scenarios" improves the KUnit test coverage for DAMON (Shu Anzai) - "mm/khugepaged: fix dirty page handling for MADV_COLLAPSE" fixes a glitch in khugepaged which was causing madvise(MADV_COLLAPSE) to transiently return -EAGAIN (Shivank Garg) - "arch, mm: consolidate hugetlb early reservation" reworks and consolidates a pile of straggly code related to reservation of hugetlb memory from bootmem and creation of CMA areas for hugetlb (Mike Rapoport) - "mm: clean up anon_vma implementation" cleans up the anon_vma implementation in various ways (Lorenzo Stoakes) - "tweaks for __alloc_pages_slowpath()" does a little streamlining of the page allocator's slowpath code (Vlastimil Babka) - "memcg: separate private and public ID namespaces" cleans up the memcg ID code and prevents the internal-only private IDs from being exposed to userspace (Shakeel Butt) - "mm: hugetlb: allocate frozen gigantic folio" cleans up the allocation of frozen folios and avoids some atomic refcount operations (Kefeng Wang) - "mm/damon: advance DAMOS-based LRU sorting" improves DAMOS's movement of memory betewwn the active and inactive LRUs and adds auto-tuning of the ratio-based quotas and of monitoring intervals (SeongJae Park) - "Support page table check on PowerPC" makes CONFIG_PAGE_TABLE_CHECK_ENFORCED work on powerpc (Andrew Donnellan) - "nodemask: align nodes_and{,not} with underlying bitmap ops" makes nodes_and() and nodes_andnot() propagate the return values from the underlying bit operations, enabling some cleanup in calling code (Yury Norov) - "mm/damon: hide kdamond and kdamond_lock from API callers" cleans up some DAMON internal interfaces (SeongJae Park) - "mm/khugepaged: cleanups and scan limit fix" does some cleanup work in khupaged and fixes a scan limit accounting issue (Shivank Garg) - "mm: balloon infrastructure cleanups" goes to town on the balloon infrastructure and its page migration function. Mainly cleanups, also some locking simplification (David Hildenbrand) - "mm/vmscan: add tracepoint and reason for kswapd_failures reset" adds additional tracepoints to the page reclaim code (Jiayuan Chen) - "Replace wq users and add WQ_PERCPU to alloc_workqueue() users" is part of Marco's kernel-wide migration from the legacy workqueue APIs over to the preferred unbound workqueues (Marco Crivellari) - "Various mm kselftests improvements/fixes" provides various unrelated improvements/fixes for the mm kselftests (Kevin Brodsky) - "mm: accelerate gigantic folio allocation" greatly speeds up gigantic folio allocation, mainly by avoiding unnecessary work in pfn_range_valid_contig() (Kefeng Wang) - "selftests/damon: improve leak detection and wss estimation reliability" improves the reliability of two of the DAMON selftests (SeongJae Park) - "mm/damon: cleanup kdamond, damon_call(), damos filter and DAMON_MIN_REGION" does some cleanup work in the core DAMON code (SeongJae Park) - "Docs/mm/damon: update intro, modules, maintainer profile, and misc" performs maintenance work on the DAMON documentation (SeongJae Park) - "mm: add and use vma_assert_stabilised() helper" refactors and cleans up the core VMA code. The main aim here is to be able to use the mmap write lock's lockdep state to perform various assertions regarding the locking which the VMA code requires (Lorenzo Stoakes) - "mm, swap: swap table phase II: unify swapin use" removes some old swap code (swap cache bypassing and swap synchronization) which wasn't working very well. Various other cleanups and simplifications were made. The end result is a 20% speedup in one benchmark (Kairui Song) - "enable PT_RECLAIM on more 64-bit architectures" makes PT_RECLAIM available on 64-bit alpha, loongarch, mips, parisc, and um. Various cleanups were performed along the way (Qi Zheng) * tag 'mm-stable-2026-02-11-19-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (325 commits) mm/memory: handle non-split locks correctly in zap_empty_pte_table() mm: move pte table reclaim code to memory.c mm: make PT_RECLAIM depends on MMU_GATHER_RCU_TABLE_FREE mm: convert __HAVE_ARCH_TLB_REMOVE_TABLE to CONFIG_HAVE_ARCH_TLB_REMOVE_TABLE config um: mm: enable MMU_GATHER_RCU_TABLE_FREE parisc: mm: enable MMU_GATHER_RCU_TABLE_FREE mips: mm: enable MMU_GATHER_RCU_TABLE_FREE LoongArch: mm: enable MMU_GATHER_RCU_TABLE_FREE alpha: mm: enable MMU_GATHER_RCU_TABLE_FREE mm: change mm/pt_reclaim.c to use asm/tlb.h instead of asm-generic/tlb.h mm/damon/stat: remove __read_mostly from memory_idle_ms_percentiles zsmalloc: make common caches global mm: add SPDX id lines to some mm source files mm/zswap: use %pe to print error pointers mm/vmscan: use %pe to print error pointers mm/readahead: fix typo in comment mm: khugepaged: fix NR_FILE_PAGES and NR_SHMEM in collapse_file() mm: refactor vma_map_pages to use vm_insert_pages mm/damon: unify address range representation with damon_addr_range mm/cma: replace snprintf with strscpy in cma_new_area ...

Merge tag 'net-next-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

2026-02-12T03:31:52Z

Pull networking updates from Paolo Abeni: "Core & protocols: - A significant effort all around the stack to guide the compiler to make the right choice when inlining code, to avoid unneeded calls for small helper and stack canary overhead in the fast-path. This generates better and faster code with very small or no text size increases, as in many cases the call generated more code than the actual inlined helper. - Extend AccECN implementation so that is now functionally complete, also allow the user-space enabling it on a per network namespace basis. - Add support for memory providers with large (above 4K) rx buffer. Paired with hw-gro, larger rx buffer sizes reduce the number of buffers traversing the stack, dincreasing single stream CPU usage by up to ~30%. - Do not add HBH header to Big TCP GSO packets. This simplifies the RX path, the TX path and the NIC drivers, and is possible because user-space taps can now interpret correctly such packets without the HBH hint. - Allow IPv6 routes to be configured with a gateway address that is resolved out of a different interface than the one specified, aligning IPv6 to IPv4 behavior. - Multi-queue aware sch_cake. This makes it possible to scale the rate shaper of sch_cake across multiple CPUs, while still enforcing a single global rate on the interface. - Add support for the nbcon (new buffer console) infrastructure to netconsole, enabling lock-free, priority-based console operations that are safer in crash scenarios. - Improve the TCP ipv6 output path to cache the flow information, saving cpu cycles, reducing cache line misses and stack use. - Improve netfilter packet tracker to resolve clashes for most protocols, avoiding unneeded drops on rare occasions. - Add IP6IP6 tunneling acceleration to the flowtable infrastructure. - Reduce tcp socket size by one cache line. - Notify neighbour changes atomically, avoiding inconsistencies between the notification sequence and the actual states sequence. - Add vsock namespace support, allowing complete isolation of vsocks across different network namespaces. - Improve xsk generic performances with cache-alignment-oriented optimizations. - Support netconsole automatic target recovery, allowing netconsole to reestablish targets when underlying low-level interface comes back online. Driver API: - Support for switching the working mode (automatic vs manual) of a DPLL device via netlink. - Introduce PHY ports representation to expose multiple front-facing media ports over a single MAC. - Introduce "rx-polarity" and "tx-polarity" device tree properties, to generalize polarity inversion requirements for differential signaling. - Add helper to create, prepare and enable managed clocks. Device drivers: - Add Huawei hinic3 PF etherner driver. - Add DWMAC glue driver for Motorcomm YT6801 PCIe ethernet controller. - Add ethernet driver for MaxLinear MxL862xx switches - Remove parallel-port Ethernet driver. - Convert existing driver timestamp configuration reporting to hwtstamp_get and remove legacy ioctl(). - Convert existing drivers to .get_rx_ring_count(), simplifing the RX ring count retrieval. Also remove the legacy fallback path. - Ethernet high-speed NICs: - Broadcom (bnxt, bng): - bnxt: add FW interface update to support FEC stats histogram and NVRAM defragmentation - bng: add TSO and H/W GRO support - nVidia/Mellanox (mlx5): - improve latency of channel restart operations, reducing the used H/W resources - add TSO support for UDP over GRE over VLAN - add flow counters support for hardware steering (HWS) rules - use a static memory area to store headers for H/W GRO, leading to 12% RX tput improvement - Intel (100G, ice, idpf): - ice: reorganizes layout of Tx and Rx rings for cacheline locality and utilizes __cacheline_group* macros on the new layouts - ice: introduces Synchronous Ethernet (SyncE) support - Meta (fbnic): - adds debugfs for firmware mailbox and tx/rx rings vectors - Ethernet virtual: - geneve: introduce GRO/GSO support for double UDP encapsulation - Ethernet NICs consumer, and embedded: - Synopsys (stmmac): - some code refactoring and cleanups - RealTek (r8169): - add support for RTL8127ATF (10G Fiber SFP) - add dash and LTR support - Airoha: - AN8811HB 2.5 Gbps phy support - Freescale (fec): - add XDP zero-copy support - Thunderbolt: - add get link setting support to allow bonding - Renesas: - add support for RZ/G3L GBETH SoC - Ethernet switches: - Maxlinear: - support R(G)MII slow rate configuration - add support for Intel GSW150 - Motorcomm (yt921x): - add DCB/QoS support - TI: - icssm-prueth: support bridging (STP/RSTP) via the switchdev framework - Ethernet PHYs: - Realtek: - enable SGMII and 2500Base-X in-band auto-negotiation - simplify and reunify C22/C45 drivers - Micrel: convert bindings to DT schema - CAN: - move skb headroom content into skb extensions, making CAN metadata access more robust - CAN drivers: - rcar_canfd: - add support for FD-only mode - add support for the RZ/T2H SoC - sja1000: cleanup the CAN state handling - WiFi: - implement EPPKE/802.1X over auth frames support - split up drop reasons better, removing generic RX_DROP - additional FTM capabilities: 6 GHz support, supported number of spatial streams and supported number of LTF repetitions - better mac80211 iterators to enumerate resources - initial UHR (Wi-Fi 8) support for cfg80211/mac80211 - WiFi drivers: - Qualcomm/Atheros: - ath11k: support for Channel Frequency Response measurement - ath12k: a significant driver refactor to support multi-wiphy devices and and pave the way for future device support in the same driver (rather than splitting to ath13k) - ath12k: support for the QCC2072 chipset - Intel: - iwlwifi: partial Neighbor Awareness Networking (NAN) support - iwlwifi: initial support for U-NII-9 and IEEE 802.11bn - RealTek (rtw89): - preparations for RTL8922DE support - Bluetooth: - implement setsockopt(BT_PHY) to set the connection packet type/PHY - set link_policy on incoming ACL connections - Bluetooth drivers: - btusb: add support for MediaTek7920, Realtek RTL8761BU and 8851BE - btqca: add WCN6855 firmware priority selection feature" * tag 'net-next-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1254 commits) bnge/bng_re: Add a new HSI net: macb: Fix tx/rx malfunction after phy link down and up af_unix: Fix memleak of newsk in unix_stream_connect(). net: ti: icssg-prueth: Add optional dependency on HSR net: dsa: add basic initial driver for MxL862xx switches net: mdio: add unlocked mdiodev C45 bus accessors net: dsa: add tag format for MxL862xx switches dt-bindings: net: dsa: add MaxLinear MxL862xx selftests: drivers: net: hw: Modify toeplitz.c to poll for packets octeontx2-pf: Unregister devlink on probe failure net: renesas: rswitch: fix forwarding offload statemachine ionic: Rate limit unknown xcvr type messages tcp: inet6_csk_xmit() optimization tcp: populate inet->cork.fl.u.ip6 in tcp_v6_syn_recv_sock() tcp: populate inet->cork.fl.u.ip6 in tcp_v6_connect() ipv6: inet6_csk_xmit() and inet6_csk_update_pmtu() use inet->cork.fl.u.ip6 ipv6: use inet->cork.fl.u.ip6 and np->final in ip6_datagram_dst_update() ipv6: use np->final in inet6_sk_rebuild_header() ipv6: add daddr/final storage in struct ipv6_pinfo net: stmmac: qcom-ethqos: fix qcom_ethqos_serdes_powerup() ...

Merge tag 'docs-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/docs/linux

2026-02-10T04:53:18Z

Pull documentation updates from Jonathan Corbet: "A slightly calmer cycle for docs this time around, though there is still a fair amount going on, including: - Some signs of life on the long-moribund Japanese translation - Documentation on policies around the use of generative tools for patch submissions, and a separate document intended for consumption by generative tools - The completion of the move of the documentation tools to tools/docs. For now we're leaving a /scripts/kernel-doc symlink behind to avoid breaking scripts - Ongoing build-system work includes the incorporation of documentation in Python code, better support for documenting variables, and lots of improvements and fixes - Automatic linking of man-page references -- cat(1), for example -- to the online pages in the HTML build ...and the usual array of typo fixes and such" * tag 'docs-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/docs/linux: (107 commits) doc: development-process: add notice on testing tools: sphinx-build-wrapper: improve its help message docs: sphinx-build-wrapper: allow -v override -q docs: kdoc: Fix pdfdocs build for tools docs: ja_JP: process: translate 'Obtain a current source tree' docs: fix 're-use' -> 'reuse' in documentation docs: ioctl-number: fix a typo in ioctl-number.rst docs: filesystems: ensure proc pid substitutable is complete docs: automarkup.py: Skip common English words as C identifiers Documentation: use a source-read extension for the index link boilerplate docs: parse_features: make documentation more consistent docs: add parse_features module documentation docs: jobserver: do some documentation improvements docs: add jobserver module documentation docs: kabi: helpers: add documentation for each "enum" value docs: kabi: helpers: add helper for debug bits 7 and 8 docs: kabi: system_symbols: end docstring phrases with a dot docs: python: abi_regex: do some improvements at documentation docs: python: abi_parser: do some improvements at documentation docs: add kabi modules documentation ...

Merge tag 'vfs-7.0-rc1.initrd' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2026-02-09T19:03:25Z

Pull vfs initrd removal from Christian Brauner: "Remove the deprecated linuxrc-based initrd code path and related dead code. The linuxrc initrd path was deprecated in 2020 and this series completes its removal. If we see real-life regressions we'll revert. The core change removes handle_initrd() and init_linuxrc() — the entire flow that ran /linuxrc from an initrd, pivoted roots, and handed off to the real root filesystem. With that gone, initrd_load() becomes void (no longer short-circuits prepare_namespace()), rd_load_image() is simplified to always load /initrd.image instead of taking a path, and rd_load_disk() is deleted. The /proc/sys/kernel/real-root-dev sysctl and its backing variable are removed since they only existed for linuxrc to communicate the real root device back to the kernel. The no-op load_ramdisk= and prompt_ramdisk= parameters are dropped, and noinitrd and ramdisk_start= gain deprecation warnings. Initramfs is entirely unaffected. The non-linuxrc initrd path (root=/dev/ram0) is preserved but now carries a deprecation warning targeting January 2027 removal" * tag 'vfs-7.0-rc1.initrd' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: init: remove /proc/sys/kernel/real-root-dev initrd: remove deprecated code path (linuxrc) init: remove deprecated "load_ramdisk" and "prompt_ramdisk" command line parameters

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2026-01-30T01:28:54Z

Cross-merge networking fixes after downstream PR (net-6.19-rc8). No adjacent changes, conflicts: drivers/net/ethernet/spacemit/k1_emac.c 2c84959167d64 ("net: spacemit: Check for netif_carrier_ok() in emac_stats_update()") f66086798f91f ("net: spacemit: Remove broken flow control support") https://lore.kernel.org/aXjAqZA3iEWD_DGM@sirena.org.uk Signed-off-by: Jakub Kicinski

Merge tag 'vfs-6.19-rc8.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2026-01-26T17:30:48Z

Pull vfs fixes from Christian Brauner: - Fix the the buggy conversion of fuse_reverse_inval_entry() introduced during the creation rework - Disallow nfs delegation requests for directories by setting simple_nosetlease() - Require an opt-in for getting readdir flag bits outside of S_DT_MASK set in d_type - Fix scheduling delayed writeback work by only scheduling when the dirty time expiry interval is non-zero and cancel the delayed work if the interval is set to zero - Use rounded_jiffies_interval for dirty time work - Check the return value of sb_set_blocksize() for romfs - Wait for batched folios to be stable in __iomap_get_folio() - Use private naming for fuse hash size - Fix the stale dentry cleanup to prevent a race that causes a UAF * tag 'vfs-6.19-rc8.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: vfs: document d_dispose_if_unused() fuse: shrink once after all buckets have been scanned fuse: clean up fuse_dentry_tree_work() fuse: add need_resched() before unlocking bucket fuse: make sure dentry is evicted if stale fuse: fix race when disposing stale dentries fuse: use private naming for fuse hash size writeback: use round_jiffies_relative for dirtytime_work iomap: wait for batched folios to be stable in __iomap_get_folio romfs: check sb_set_blocksize() return value docs: clarify that dirtytime_expire_seconds=0 disables writeback writeback: fix 100% CPU usage when dirtytime_expire_interval is 0 readdir: require opt-in for d_type flags vboxsf: don't allow delegations to be set on directories ceph: don't allow delegations to be set on directories gfs2: don't allow delegations to be set on directories 9p: don't allow delegations to be set on directories smb/client: properly disallow delegations on directories nfs: properly disallow delegation requests on directories fuse: fix conversion of fuse_reverse_inval_entry() to start_removing()

net: expand NETDEV_RSS_KEY_LEN to 256 bytes

2026-01-25T21:20:46Z

NETDEV_RSS_KEY_LEN has been set to 52 bytes in 2014, until now. Jakub suggested we bump the size to 128 bytes or more. Some drivers (like idpf) were already working around the core limit. Since this change might cause some issues in admin scripts, bump it directly to 256 in one go. tjbp26:~# cat /proc/sys/net/core/netdev_rss_key | wc -c 768 tjbp26:~# ethtool -x eth1 RX flow hash indirection table for eth1 with 32 RX ring(s): ... RSS hash key: fe:16:5b:2f:93:85:c2:c9:c1:ef:bd:60:c6:e0:2b:99:4d:bf:b7:14:c8:1e:8d:cb:31:17:51:da:55:eb:91:d9:9e:f9:89:9b:44:a1:dc:08:72:3a:b3:d6:31:86:9a:fe:02:3a:0d:eb:a1:7c:f5:a3:51:3b:08:56:c9:3f:71:69:01:ba:70:38 RSS hash function: toeplitz: on xor: off crc32: off Suggested-by: Jakub Kicinski Link: https://lore.kernel.org/netdev/20260122075206.504ec591@kernel.org/ Signed-off-by: Eric Dumazet Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20260122190349.2771064-1-edumazet@google.com Signed-off-by: Jakub Kicinski