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5 dayseventpoll: Fix semi-unbounded recursionJann Horn1-14/+46
commit f2e467a48287c868818085aa35389a224d226732 upstream. Ensure that epoll instances can never form a graph deeper than EP_MAX_NESTS+1 links. Currently, ep_loop_check_proc() ensures that the graph is loop-free and does some recursion depth checks, but those recursion depth checks don't limit the depth of the resulting tree for two reasons: - They don't look upwards in the tree. - If there are multiple downwards paths of different lengths, only one of the paths is actually considered for the depth check since commit 28d82dc1c4ed ("epoll: limit paths"). Essentially, the current recursion depth check in ep_loop_check_proc() just serves to prevent it from recursing too deeply while checking for loops. A more thorough check is done in reverse_path_check() after the new graph edge has already been created; this checks, among other things, that no paths going upwards from any non-epoll file with a length of more than 5 edges exist. However, this check does not apply to non-epoll files. As a result, it is possible to recurse to a depth of at least roughly 500, tested on v6.15. (I am unsure if deeper recursion is possible; and this may have changed with commit 8c44dac8add7 ("eventpoll: Fix priority inversion problem").) To fix it: 1. In ep_loop_check_proc(), note the subtree depth of each visited node, and use subtree depths for the total depth calculation even when a subtree has already been visited. 2. Add ep_get_upwards_depth_proc() for similarly determining the maximum depth of an upwards walk. 3. In ep_loop_check(), use these values to limit the total path length between epoll nodes to EP_MAX_NESTS edges. Fixes: 22bacca48a17 ("epoll: prevent creating circular epoll structures") Cc: stable@vger.kernel.org Signed-off-by: Jann Horn <jannh@google.com> Link: https://lore.kernel.org/20250711-epoll-recursion-fix-v1-1-fb2457c33292@google.com Signed-off-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-17eventpoll: don't decrement ep refcount while still holding the ep mutexLinus Torvalds1-7/+5
commit 8c2e52ebbe885c7eeaabd3b7ddcdc1246fc400d2 upstream. Jann Horn points out that epoll is decrementing the ep refcount and then doing a mutex_unlock(&ep->mtx); afterwards. That's very wrong, because it can lead to a use-after-free. That pattern is actually fine for the very last reference, because the code in question will delay the actual call to "ep_free(ep)" until after it has unlocked the mutex. But it's wrong for the much subtler "next to last" case when somebody *else* may also be dropping their reference and free the ep while we're still using the mutex. Note that this is true even if that other user is also using the same ep mutex: mutexes, unlike spinlocks, can not be used for object ownership, even if they guarantee mutual exclusion. A mutex "unlock" operation is not atomic, and as one user is still accessing the mutex as part of unlocking it, another user can come in and get the now released mutex and free the data structure while the first user is still cleaning up. See our mutex documentation in Documentation/locking/mutex-design.rst, in particular the section [1] about semantics: "mutex_unlock() may access the mutex structure even after it has internally released the lock already - so it's not safe for another context to acquire the mutex and assume that the mutex_unlock() context is not using the structure anymore" So if we drop our ep ref before the mutex unlock, but we weren't the last one, we may then unlock the mutex, another user comes in, drops _their_ reference and releases the 'ep' as it now has no users - all while the mutex_unlock() is still accessing it. Fix this by simply moving the ep refcount dropping to outside the mutex: the refcount itself is atomic, and doesn't need mutex protection (that's the whole _point_ of refcounts: unlike mutexes, they are inherently about object lifetimes). Reported-by: Jann Horn <jannh@google.com> Link: https://docs.kernel.org/locking/mutex-design.html#semantics [1] Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-02fs/eventpoll: fix endless busy loop after timeout has expiredMax Kellermann1-3/+4
After commit 0a65bc27bd64 ("eventpoll: Set epoll timeout if it's in the future"), the following program would immediately enter a busy loop in the kernel: ``` int main() { int e = epoll_create1(0); struct epoll_event event = {.events = EPOLLIN}; epoll_ctl(e, EPOLL_CTL_ADD, 0, &event); const struct timespec timeout = {.tv_nsec = 1}; epoll_pwait2(e, &event, 1, &timeout, 0); } ``` This happens because the given (non-zero) timeout of 1 nanosecond usually expires before ep_poll() is entered and then ep_schedule_timeout() returns false, but `timed_out` is never set because the code line that sets it is skipped. This quickly turns into a soft lockup, RCU stalls and deadlocks, inflicting severe headaches to the whole system. When the timeout has expired, we don't need to schedule a hrtimer, but we should set the `timed_out` variable. Therefore, I suggest moving the ep_schedule_timeout() check into the `timed_out` expression instead of skipping it. brauner: Note that there was an earlier fix by Joe Damato in response to my bug report in [1]. Fixes: 0a65bc27bd64 ("eventpoll: Set epoll timeout if it's in the future") Cc: Joe Damato <jdamato@fastly.com> Cc: stable@vger.kernel.org Signed-off-by: Max Kellermann <max.kellermann@ionos.com> Link: https://lore.kernel.org/20250429153419.94723-1-jdamato@fastly.com [1] Link: https://lore.kernel.org/20250429185827.3564438-1-max.kellermann@ionos.com Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-04-17eventpoll: Set epoll timeout if it's in the futureJoe Damato1-1/+9
Avoid an edge case where epoll_wait arms a timer and calls schedule() even if the timer will expire immediately. For example: if the user has specified an epoll busy poll usecs which is equal or larger than the epoll_wait/epoll_pwait2 timeout, it is unnecessary to call schedule_hrtimeout_range; the busy poll usecs have consumed the entire timeout duration so it is unnecessary to induce scheduling latency by calling schedule() (via schedule_hrtimeout_range). This can be measured using a simple bpftrace script: tracepoint:sched:sched_switch / args->prev_pid == $1 / { print(kstack()); print(ustack()); } Before this patch is applied: Testing an epoll_wait app with busy poll usecs set to 1000, and epoll_wait timeout set to 1ms using the script above shows: __traceiter_sched_switch+69 __schedule+1495 schedule+32 schedule_hrtimeout_range+159 do_epoll_wait+1424 __x64_sys_epoll_wait+97 do_syscall_64+95 entry_SYSCALL_64_after_hwframe+118 epoll_wait+82 Which is unexpected; the busy poll usecs should have consumed the entire timeout and there should be no reason to arm a timer. After this patch is applied: the same test scenario does not generate a call to schedule() in the above edge case. If the busy poll usecs are reduced (for example usecs: 100, epoll_wait timeout 1ms) the timer is armed as expected. Fixes: bf3b9f6372c4 ("epoll: Add busy poll support to epoll with socket fds.") Signed-off-by: Joe Damato <jdamato@fastly.com> Link: https://lore.kernel.org/20250416185826.26375-1-jdamato@fastly.com Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-03-26Merge tag 'net-next-6.15' of ↵Linus Torvalds1-4/+4
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Jakub Kicinski: "Core & protocols: - Continue Netlink conversions to per-namespace RTNL lock (IPv4 routing, routing rules, routing next hops, ARP ioctls) - Continue extending the use of netdev instance locks. As a driver opt-in protect queue operations and (in due course) ethtool operations with the instance lock and not RTNL lock. - Support collecting TCP timestamps (data submitted, sent, acked) in BPF, allowing for transparent (to the application) and lower overhead tracking of TCP RPC performance. - Tweak existing networking Rx zero-copy infra to support zero-copy Rx via io_uring. - Optimize MPTCP performance in single subflow mode by 29%. - Enable GRO on packets which went thru XDP CPU redirect (were queued for processing on a different CPU). Improving TCP stream performance up to 2x. - Improve performance of contended connect() by 200% by searching for an available 4-tuple under RCU rather than a spin lock. Bring an additional 229% improvement by tweaking hash distribution. - Avoid unconditionally touching sk_tsflags on RX, improving performance under UDP flood by as much as 10%. - Avoid skb_clone() dance in ping_rcv() to improve performance under ping flood. - Avoid FIB lookup in netfilter if socket is available, 20% perf win. - Rework network device creation (in-kernel) API to more clearly identify network namespaces and their roles. There are up to 4 namespace roles but we used to have just 2 netns pointer arguments, interpreted differently based on context. - Use sysfs_break_active_protection() instead of trylock to avoid deadlocks between unregistering objects and sysfs access. - Add a new sysctl and sockopt for capping max retransmit timeout in TCP. - Support masking port and DSCP in routing rule matches. - Support dumping IPv4 multicast addresses with RTM_GETMULTICAST. - Support specifying at what time packet should be sent on AF_XDP sockets. - Expose TCP ULP diagnostic info (for TLS and MPTCP) to non-admin users. - Add Netlink YAML spec for WiFi (nl80211) and conntrack. - Introduce EXPORT_IPV6_MOD() and EXPORT_IPV6_MOD_GPL() for symbols which only need to be exported when IPv6 support is built as a module. - Age FDB entries based on Rx not Tx traffic in VxLAN, similar to normal bridging. - Allow users to specify source port range for GENEVE tunnels. - netconsole: allow attaching kernel release, CPU ID and task name to messages as metadata Driver API: - Continue rework / fixing of Energy Efficient Ethernet (EEE) across the SW layers. Delegate the responsibilities to phylink where possible. Improve its handling in phylib. - Support symmetric OR-XOR RSS hashing algorithm. - Support tracking and preserving IRQ affinity by NAPI itself. - Support loopback mode speed selection for interface selftests. Device drivers: - Remove the IBM LCS driver for s390 - Remove the sb1000 cable modem driver - Add support for SFP module access over SMBus - Add MCTP transport driver for MCTP-over-USB - Enable XDP metadata support in multiple drivers - Ethernet high-speed NICs: - Broadcom (bnxt): - add PCIe TLP Processing Hints (TPH) support for new AMD platforms - support dumping RoCE queue state for debug - opt into instance locking - Intel (100G, ice, idpf): - ice: rework MSI-X IRQ management and distribution - ice: support for E830 devices - iavf: add support for Rx timestamping - iavf: opt into instance locking - nVidia/Mellanox: - mlx4: use page pool memory allocator for Rx - mlx5: support for one PTP device per hardware clock - mlx5: support for 200Gbps per-lane link modes - mlx5: move IPSec policy check after decryption - AMD/Solarflare: - support FW flashing via devlink - Cisco (enic): - use page pool memory allocator for Rx - enable 32, 64 byte CQEs - get max rx/tx ring size from the device - Meta (fbnic): - support flow steering and RSS configuration - report queue stats - support TCP segmentation - support IRQ coalescing - support ring size configuration - Marvell/Cavium: - support AF_XDP - Wangxun: - support for PTP clock and timestamping - Huawei (hibmcge): - checksum offload - add more statistics - Ethernet virtual: - VirtIO net: - aggressively suppress Tx completions, improve perf by 96% with 1 CPU and 55% with 2 CPUs - expose NAPI to IRQ mapping and persist NAPI settings - Google (gve): - support XDP in DQO RDA Queue Format - opt into instance locking - Microsoft vNIC: - support BIG TCP - Ethernet NICs consumer, and embedded: - Synopsys (stmmac): - cleanup Tx and Tx clock setting and other link-focused cleanups - enable SGMII and 2500BASEX mode switching for Intel platforms - support Sophgo SG2044 - Broadcom switches (b53): - support for BCM53101 - TI: - iep: add perout configuration support - icssg: support XDP - Cadence (macb): - implement BQL - Xilinx (axinet): - support dynamic IRQ moderation and changing coalescing at runtime - implement BQL - report standard stats - MediaTek: - support phylink managed EEE - Intel: - igc: don't restart the interface on every XDP program change - RealTek (r8169): - support reading registers of internal PHYs directly - increase max jumbo packet size on RTL8125/RTL8126 - Airoha: - support for RISC-V NPU packet processing unit - enable scatter-gather and support MTU up to 9kB - Tehuti (tn40xx): - support cards with TN4010 MAC and an Aquantia AQR105 PHY - Ethernet PHYs: - support for TJA1102S, TJA1121 - dp83tg720: add randomized polling intervals for link detection - dp83822: support changing the transmit amplitude voltage - support for LEDs on 88q2xxx - CAN: - canxl: support Remote Request Substitution bit access - flexcan: add S32G2/S32G3 SoC - WiFi: - remove cooked monitor support - strict mode for better AP testing - basic EPCS support - OMI RX bandwidth reduction support - batman-adv: add support for jumbo frames - WiFi drivers: - RealTek (rtw88): - support RTL8814AE and RTL8814AU - RealTek (rtw89): - switch using wiphy_lock and wiphy_work - add BB context to manipulate two PHY as preparation of MLO - improve BT-coexistence mechanism to play A2DP smoothly - Intel (iwlwifi): - add new iwlmld sub-driver for latest HW/FW combinations - MediaTek (mt76): - preparation for mt7996 Multi-Link Operation (MLO) support - Qualcomm/Atheros (ath12k): - continued work on MLO - Silabs (wfx): - Wake-on-WLAN support - Bluetooth: - add support for skb TX SND/COMPLETION timestamping - hci_core: enable buffer flow control for SCO/eSCO - coredump: log devcd dumps into the monitor - Bluetooth drivers: - intel: add support to configure TX power - nxp: handle bootloader error during cmd5 and cmd7" * tag 'net-next-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1681 commits) unix: fix up for "apparmor: add fine grained af_unix mediation" mctp: Fix incorrect tx flow invalidation condition in mctp-i2c net: usb: asix: ax88772: Increase phy_name size net: phy: Introduce PHY_ID_SIZE — minimum size for PHY ID string net: libwx: fix Tx L4 checksum net: libwx: fix Tx descriptor content for some tunnel packets atm: Fix NULL pointer dereference net: tn40xx: add pci-id of the aqr105-based Tehuti TN4010 cards net: tn40xx: prepare tn40xx driver to find phy of the TN9510 card net: tn40xx: create swnode for mdio and aqr105 phy and add to mdiobus net: phy: aquantia: add essential functions to aqr105 driver net: phy: aquantia: search for firmware-name in fwnode net: phy: aquantia: add probe function to aqr105 for firmware loading net: phy: Add swnode support to mdiobus_scan gve: add XDP DROP and PASS support for DQ gve: update XDP allocation path support RX buffer posting gve: merge packet buffer size fields gve: update GQ RX to use buf_size gve: introduce config-based allocation for XDP gve: remove xdp_xsk_done and xdp_xsk_wakeup statistics ...
2025-03-24Merge tag 'vfs-6.15-rc1.eventpoll' of ↵Linus Torvalds1-24/+63
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs eventpoll updates from Christian Brauner: "This contains a few preparatory changes to eventpoll to allow io_uring to support epoll" * tag 'vfs-6.15-rc1.eventpoll' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: eventpoll: add epoll_sendevents() helper eventpoll: abstract out ep_try_send_events() helper eventpoll: abstract out parameter sanity checking
2025-02-27epoll: simplify ep_busy_loop by removing always 0 argumentLin Feng1-4/+4
Commit 00b27634bc471("epoll: replace gotos with a proper loop") refactored ep_poll and always feeds ep_busy_loop with a time_out value of 0, nonblock mode for ep_busy_loop has sunk since, IOW nonblock mode checking has been taken over by ep_poll itself, codes snipped: static int ep_poll(struct eventpoll *ep... { ... if (timed_out) return 0; eavail = ep_busy_loop(ep, timed_out); ... } Given this fact codes can be simplified a bit for ep_busy_loop. Signed-off-by: Lin Feng <linf@wangsu.com> Link: https://lore.kernel.org/r/20250227033412.5873-1-linf@wangsu.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-02-20eventpoll: add epoll_sendevents() helperJens Axboe1-0/+20
Basic helper that copies ready events to the specified userspace address. The event checking is quick and racy, it's up to the caller to ensure it retries appropriately in case 0 events are copied. Signed-off-by: Jens Axboe <axboe@kernel.dk> Link: https://lore.kernel.org/r/20250219172552.1565603-4-axboe@kernel.dk Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-02-20eventpoll: abstract out ep_try_send_events() helperJens Axboe1-10/+18
In preparation for reusing this helper in another epoll setup helper, abstract it out. Signed-off-by: Jens Axboe <axboe@kernel.dk> Link: https://lore.kernel.org/r/20250219172552.1565603-3-axboe@kernel.dk Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-02-20eventpoll: abstract out parameter sanity checkingJens Axboe1-14/+25
Add a helper that checks the validity of the file descriptor and other parameters passed in to epoll_wait(). Signed-off-by: Jens Axboe <axboe@kernel.dk> Link: https://lore.kernel.org/r/20250219172552.1565603-2-axboe@kernel.dk Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-02-17net: use napi_id_valid helperStefano Jordhani1-4/+4
In commit 6597e8d35851 ("netdev-genl: Elide napi_id when not present"), napi_id_valid function was added. Use the helper to refactor open-coded checks in the source. Suggested-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Stefano Jordhani <sjordhani@gmail.com> Reviewed-by: Joe Damato <jdamato@fastly.com> Reviewed-by: Jens Axboe <axboe@kernel.dk> # for iouring Link: https://patch.msgid.link/20250214181801.931-1-sjordhani@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-28treewide: const qualify ctl_tables where applicableJoel Granados1-1/+1
Add the const qualifier to all the ctl_tables in the tree except for watchdog_hardlockup_sysctl, memory_allocation_profiling_sysctls, loadpin_sysctl_table and the ones calling register_net_sysctl (./net, drivers/inifiniband dirs). These are special cases as they use a registration function with a non-const qualified ctl_table argument or modify the arrays before passing them on to the registration function. Constifying ctl_table structs will prevent the modification of proc_handler function pointers as the arrays would reside in .rodata. This is made possible after commit 78eb4ea25cd5 ("sysctl: treewide: constify the ctl_table argument of proc_handlers") constified all the proc_handlers. Created this by running an spatch followed by a sed command: Spatch: virtual patch @ depends on !(file in "net") disable optional_qualifier @ identifier table_name != { watchdog_hardlockup_sysctl, iwcm_ctl_table, ucma_ctl_table, memory_allocation_profiling_sysctls, loadpin_sysctl_table }; @@ + const struct ctl_table table_name [] = { ... }; sed: sed --in-place \ -e "s/struct ctl_table .table = &uts_kern/const struct ctl_table *table = \&uts_kern/" \ kernel/utsname_sysctl.c Reviewed-by: Song Liu <song@kernel.org> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> # for kernel/trace/ Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> # SCSI Reviewed-by: Darrick J. Wong <djwong@kernel.org> # xfs Acked-by: Jani Nikula <jani.nikula@intel.com> Acked-by: Corey Minyard <cminyard@mvista.com> Acked-by: Wei Liu <wei.liu@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Bill O'Donnell <bodonnel@redhat.com> Acked-by: Baoquan He <bhe@redhat.com> Acked-by: Ashutosh Dixit <ashutosh.dixit@intel.com> Acked-by: Anna Schumaker <anna.schumaker@oracle.com> Signed-off-by: Joel Granados <joel.granados@kernel.org>
2024-11-21Merge tag 'net-next-6.13' of ↵Linus Torvalds1-2/+34
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Paolo Abeni: "The most significant set of changes is the per netns RTNL. The new behavior is disabled by default, regression risk should be contained. Notably the new config knob PTP_1588_CLOCK_VMCLOCK will inherit its default value from PTP_1588_CLOCK_KVM, as the first is intended to be a more reliable replacement for the latter. Core: - Started a very large, in-progress, effort to make the RTNL lock scope per network-namespace, thus reducing the lock contention significantly in the containerized use-case, comprising: - RCU-ified some relevant slices of the FIB control path - introduce basic per netns locking helpers - namespacified the IPv4 address hash table - remove rtnl_register{,_module}() in favour of rtnl_register_many() - refactor rtnl_{new,del,set}link() moving as much validation as possible out of RTNL lock - convert all phonet doit() and dumpit() handlers to RCU - convert IPv4 addresses manipulation to per-netns RTNL - convert virtual interface creation to per-netns RTNL the per-netns lock infrastructure is guarded by the CONFIG_DEBUG_NET_SMALL_RTNL knob, disabled by default ad interim. - Introduce NAPI suspension, to efficiently switching between busy polling (NAPI processing suspended) and normal processing. - Migrate the IPv4 routing input, output and control path from direct ToS usage to DSCP macros. This is a work in progress to make ECN handling consistent and reliable. - Add drop reasons support to the IPv4 rotue input path, allowing better introspection in case of packets drop. - Make FIB seqnum lockless, dropping RTNL protection for read access. - Make inet{,v6} addresses hashing less predicable. - Allow providing timestamp OPT_ID via cmsg, to correlate TX packets and timestamps Things we sprinkled into general kernel code: - Add small file operations for debugfs, to reduce the struct ops size. - Refactoring and optimization for the implementation of page_frag API, This is a preparatory work to consolidate the page_frag implementation. Netfilter: - Optimize set element transactions to reduce memory consumption - Extended netlink error reporting for attribute parser failure. - Make legacy xtables configs user selectable, giving users the option to configure iptables without enabling any other config. - Address a lot of false-positive RCU issues, pointed by recent CI improvements. BPF: - Put xsk sockets on a struct diet and add various cleanups. Overall, this helps to bump performance by 12% for some workloads. - Extend BPF selftests to increase coverage of XDP features in combination with BPF cpumap. - Optimize and homogenize bpf_csum_diff helper for all archs and also add a batch of new BPF selftests for it. - Extend netkit with an option to delegate skb->{mark,priority} scrubbing to its BPF program. - Make the bpf_get_netns_cookie() helper available also to tc(x) BPF programs. Protocols: - Introduces 4-tuple hash for connected udp sockets, speeding-up significantly connected sockets lookup. - Add a fastpath for some TCP timers that usually expires after close, the socket lock contention. - Add inbound and outbound xfrm state caches to speed up state lookups. - Avoid sending MPTCP advertisements on stale subflows, reducing risks on loosing them. - Make neighbours table flushing more scalable, maintaining per device neigh lists. Driver API: - Introduce a unified interface to configure transmission H/W shaping, and expose it to user-space via generic-netlink. - Add support for per-NAPI config via netlink. This makes napi configuration persistent across queues removal and re-creation. Requires driver updates, currently supported drivers are: nVidia/Mellanox mlx4 and mlx5, Broadcom brcm and Intel ice. - Add ethtool support for writing SFP / PHY firmware blocks. - Track RSS context allocation from ethtool core. - Implement support for mirroring to DSA CPU port, via TC mirror offload. - Consolidate FDB updates notification, to avoid duplicates on device-specific entries. - Expose DPLL clock quality level to the user-space. - Support master-slave PHY config via device tree. Tests and tooling: - forwarding: introduce deferred commands, to simplify the cleanup phase Drivers: - Updated several drivers - Amazon vNic, Google vNic, Microsoft vNic, Intel e1000e and Broadcom Tigon3 - to use netdev-genl to link the IRQs and queues to NAPI IDs, allowing busy polling and better introspection. - Ethernet high-speed NICs: - nVidia/Mellanox: - mlx5: - a large refactor to implement support for cross E-Switch scheduling - refactor H/W conter management to let it scale better - H/W GRO cleanups - Intel (100G, ice):: - add support for ethtool reset - implement support for per TX queue H/W shaping - AMD/Solarflare: - implement per device queue stats support - Broadcom (bnxt): - improve wildcard l4proto on IPv4/IPv6 ntuple rules - Marvell Octeon: - Add representor support for each Resource Virtualization Unit (RVU) device. - Hisilicon: - add support for the BMC Gigabit Ethernet - IBM (EMAC): - driver cleanup and modernization - Cisco (VIC): - raise the queues number limit to 256 - Ethernet virtual: - Google vNIC: - implement page pool support - macsec: - inherit lower device's features and TSO limits when offloading - virtio_net: - enable premapped mode by default - support for XDP socket(AF_XDP) zerocopy TX - wireguard: - set the TSO max size to be GSO_MAX_SIZE, to aggregate larger packets. - Ethernet NICs embedded and virtual: - Broadcom ASP: - enable software timestamping - Freescale: - add enetc4 PF driver - MediaTek: Airoha SoC: - implement BQL support - RealTek r8169: - enable TSO by default on r8168/r8125 - implement extended ethtool stats - Renesas AVB: - enable TX checksum offload - Synopsys (stmmac): - support header splitting for vlan tagged packets - move common code for DWMAC4 and DWXGMAC into a separate FPE module. - add dwmac driver support for T-HEAD TH1520 SoC - Synopsys (xpcs): - driver refactor and cleanup - TI: - icssg_prueth: add VLAN offload support - Xilinx emaclite: - add clock support - Ethernet switches: - Microchip: - implement support for the lan969x Ethernet switch family - add LAN9646 switch support to KSZ DSA driver - Ethernet PHYs: - Marvel: 88q2x: enable auto negotiation - Microchip: add support for LAN865X Rev B1 and LAN867X Rev C1/C2 - PTP: - Add support for the Amazon virtual clock device - Add PtP driver for s390 clocks - WiFi: - mac80211 - EHT 1024 aggregation size for transmissions - new operation to indicate that a new interface is to be added - support radio separation of multi-band devices - move wireless extension spy implementation to libiw - Broadcom: - brcmfmac: optional LPO clock support - Microchip: - add support for Atmel WILC3000 - Qualcomm (ath12k): - firmware coredump collection support - add debugfs support for a multitude of statistics - Qualcomm (ath5k): - Arcadyan ARV45XX AR2417 & Gigaset SX76[23] AR241[34]A support - Realtek: - rtw88: 8821au and 8812au USB adapters support - rtw89: add thermal protection - rtw89: fine tune BT-coexsitence to improve user experience - rtw89: firmware secure boot for WiFi 6 chip - Bluetooth - add Qualcomm WCN785x support for ids Foxconn 0xe0fc/0xe0f3 and 0x13d3:0x3623 - add Realtek RTL8852BE support for id Foxconn 0xe123 - add MediaTek MT7920 support for wireless module ids - btintel_pcie: add handshake between driver and firmware - btintel_pcie: add recovery mechanism - btnxpuart: add GPIO support to power save feature" * tag 'net-next-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1475 commits) mm: page_frag: fix a compile error when kernel is not compiled Documentation: tipc: fix formatting issue in tipc.rst selftests: nic_performance: Add selftest for performance of NIC driver selftests: nic_link_layer: Add selftest case for speed and duplex states selftests: nic_link_layer: Add link layer selftest for NIC driver bnxt_en: Add FW trace coredump segments to the coredump bnxt_en: Add a new ethtool -W dump flag bnxt_en: Add 2 parameters to bnxt_fill_coredump_seg_hdr() bnxt_en: Add functions to copy host context memory bnxt_en: Do not free FW log context memory bnxt_en: Manage the FW trace context memory bnxt_en: Allocate backing store memory for FW trace logs bnxt_en: Add a 'force' parameter to bnxt_free_ctx_mem() bnxt_en: Refactor bnxt_free_ctx_mem() bnxt_en: Add mem_valid bit to struct bnxt_ctx_mem_type bnxt_en: Update firmware interface spec to 1.10.3.85 selftests/bpf: Add some tests with sockmap SK_PASS bpf: fix recursive lock when verdict program return SK_PASS wireguard: device: support big tcp GSO wireguard: selftests: load nf_conntrack if not present ...
2024-11-18Merge tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds1-27/+11
Pull 'struct fd' class updates from Al Viro: "The bulk of struct fd memory safety stuff Making sure that struct fd instances are destroyed in the same scope where they'd been created, getting rid of reassignments and passing them by reference, converting to CLASS(fd{,_pos,_raw}). We are getting very close to having the memory safety of that stuff trivial to verify" * tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits) deal with the last remaing boolean uses of fd_file() css_set_fork(): switch to CLASS(fd_raw, ...) memcg_write_event_control(): switch to CLASS(fd) assorted variants of irqfd setup: convert to CLASS(fd) do_pollfd(): convert to CLASS(fd) convert do_select() convert vfs_dedupe_file_range(). convert cifs_ioctl_copychunk() convert media_request_get_by_fd() convert spu_run(2) switch spufs_calls_{get,put}() to CLASS() use convert cachestat(2) convert do_preadv()/do_pwritev() fdget(), more trivial conversions fdget(), trivial conversions privcmd_ioeventfd_assign(): don't open-code eventfd_ctx_fdget() o2hb_region_dev_store(): avoid goto around fdget()/fdput() introduce "fd_pos" class, convert fdget_pos() users to it. fdget_raw() users: switch to CLASS(fd_raw) convert vmsplice() to CLASS(fd) ...
2024-11-18Merge tag 'vfs-6.13.file' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs file updates from Christian Brauner: "This contains changes the changes for files for this cycle: - Introduce a new reference counting mechanism for files. As atomic_inc_not_zero() is implemented with a try_cmpxchg() loop it has O(N^2) behaviour under contention with N concurrent operations and it is in a hot path in __fget_files_rcu(). The rcuref infrastructures remedies this problem by using an unconditional increment relying on safe- and dead zones to make this work and requiring rcu protection for the data structure in question. This not just scales better it also introduces overflow protection. However, in contrast to generic rcuref, files require a memory barrier and thus cannot rely on *_relaxed() atomic operations and also require to be built on atomic_long_t as having massive amounts of reference isn't unheard of even if it is just an attack. This adds a file specific variant instead of making this a generic library. This has been tested by various people and it gives consistent improvement up to 3-5% on workloads with loads of threads. - Add a fastpath for find_next_zero_bit(). Skip 2-levels searching via find_next_zero_bit() when there is a free slot in the word that contains the next fd. This improves pts/blogbench-1.1.0 read by 8% and write by 4% on Intel ICX 160. - Conditionally clear full_fds_bits since it's very likely that a bit in full_fds_bits has been cleared during __clear_open_fds(). This improves pts/blogbench-1.1.0 read up to 13%, and write up to 5% on Intel ICX 160. - Get rid of all lookup_*_fdget_rcu() variants. They were used to lookup files without taking a reference count. That became invalid once files were switched to SLAB_TYPESAFE_BY_RCU and now we're always taking a reference count. Switch to an already existing helper and remove the legacy variants. - Remove pointless includes of <linux/fdtable.h>. - Avoid cmpxchg() in close_files() as nobody else has a reference to the files_struct at that point. - Move close_range() into fs/file.c and fold __close_range() into it. - Cleanup calling conventions of alloc_fdtable() and expand_files(). - Merge __{set,clear}_close_on_exec() into one. - Make __set_open_fd() set cloexec as well instead of doing it in two separate steps" * tag 'vfs-6.13.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: selftests: add file SLAB_TYPESAFE_BY_RCU recycling stressor fs: port files to file_ref fs: add file_ref expand_files(): simplify calling conventions make __set_open_fd() set cloexec state as well fs: protect backing files with rcu file.c: merge __{set,clear}_close_on_exec() alloc_fdtable(): change calling conventions. fs/file.c: add fast path in find_next_fd() fs/file.c: conditionally clear full_fds fs/file.c: remove sanity_check and add likely/unlikely in alloc_fd() move close_range(2) into fs/file.c, fold __close_range() into it close_files(): don't bother with xchg() remove pointless includes of <linux/fdtable.h> get rid of ...lookup...fdget_rcu() family
2024-11-11eventpoll: Control irq suspension for prefer_busy_pollMartin Karsten1-1/+31
When events are reported to userland and prefer_busy_poll is set, irqs are temporarily suspended using napi_suspend_irqs. If no events are found and ep_poll would go to sleep, irq suspension is cancelled using napi_resume_irqs. Signed-off-by: Martin Karsten <mkarsten@uwaterloo.ca> Co-developed-by: Joe Damato <jdamato@fastly.com> Signed-off-by: Joe Damato <jdamato@fastly.com> Tested-by: Joe Damato <jdamato@fastly.com> Tested-by: Martin Karsten <mkarsten@uwaterloo.ca> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Reviewed-by: Sridhar Samudrala <sridhar.samudrala@intel.com> Link: https://patch.msgid.link/20241109050245.191288-5-jdamato@fastly.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-11eventpoll: Trigger napi_busy_loop, if prefer_busy_poll is setMartin Karsten1-1/+3
Setting prefer_busy_poll now leads to an effectively nonblocking iteration though napi_busy_loop, even when busy_poll_usecs is 0. Signed-off-by: Martin Karsten <mkarsten@uwaterloo.ca> Co-developed-by: Joe Damato <jdamato@fastly.com> Signed-off-by: Joe Damato <jdamato@fastly.com> Tested-by: Joe Damato <jdamato@fastly.com> Tested-by: Martin Karsten <mkarsten@uwaterloo.ca> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Reviewed-by: Sridhar Samudrala <sridhar.samudrala@intel.com> Link: https://patch.msgid.link/20241109050245.191288-4-jdamato@fastly.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-03fdget(), more trivial conversionsAl Viro1-11/+4
all failure exits prior to fdget() leave the scope, all matching fdput() are immediately followed by leaving the scope. [xfs_ioc_commit_range() chunk moved here as well] Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-11-03fdget(), trivial conversionsAl Viro1-16/+7
fdget() is the first thing done in scope, all matching fdput() are immediately followed by leaving the scope. Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-10-30fs: port files to file_refChristian Brauner1-1/+1
Port files to rely on file_ref reference to improve scaling and gain overflow protection. - We continue to WARN during get_file() in case a file that is already marked dead is revived as get_file() is only valid if the caller already holds a reference to the file. This hasn't changed just the check changes. - The semantics for epoll and ttm's dmabuf usage have changed. Both epoll and ttm synchronize with __fput() to prevent the underlying file from beeing freed. (1) epoll Explaining epoll is straightforward using a simple diagram. Essentially, the mutex of the epoll instance needs to be taken in both __fput() and around epi_fget() preventing the file from being freed while it is polled or preventing the file from being resurrected. CPU1 CPU2 fput(file) -> __fput(file) -> eventpoll_release(file) -> eventpoll_release_file(file) mutex_lock(&ep->mtx) epi_item_poll() -> epi_fget() -> file_ref_get(file) mutex_unlock(&ep->mtx) mutex_lock(&ep->mtx); __ep_remove() mutex_unlock(&ep->mtx); -> kmem_cache_free(file) (2) ttm dmabuf This explanation is a bit more involved. A regular dmabuf file stashed the dmabuf in file->private_data and the file in dmabuf->file: file->private_data = dmabuf; dmabuf->file = file; The generic release method of a dmabuf file handles file specific things: f_op->release::dma_buf_file_release() while the generic dentry release method of a dmabuf handles dmabuf freeing including driver specific things: dentry->d_release::dma_buf_release() During ttm dmabuf initialization in ttm_object_device_init() the ttm driver copies the provided struct dma_buf_ops into a private location: struct ttm_object_device { spinlock_t object_lock; struct dma_buf_ops ops; void (*dmabuf_release)(struct dma_buf *dma_buf); struct idr idr; }; ttm_object_device_init(const struct dma_buf_ops *ops) { // copy original dma_buf_ops in private location tdev->ops = *ops; // stash the release method of the original struct dma_buf_ops tdev->dmabuf_release = tdev->ops.release; // override the release method in the copy of the struct dma_buf_ops // with ttm's own dmabuf release method tdev->ops.release = ttm_prime_dmabuf_release; } When a new dmabuf is created the struct dma_buf_ops with the overriden release method set to ttm_prime_dmabuf_release is passed in exp_info.ops: DEFINE_DMA_BUF_EXPORT_INFO(exp_info); exp_info.ops = &tdev->ops; exp_info.size = prime->size; exp_info.flags = flags; exp_info.priv = prime; The call to dma_buf_export() then sets mutex_lock_interruptible(&prime->mutex); dma_buf = dma_buf_export(&exp_info) { dmabuf->ops = exp_info->ops; } mutex_unlock(&prime->mutex); which creates a new dmabuf file and then install a file descriptor to it in the callers file descriptor table: ret = dma_buf_fd(dma_buf, flags); When that dmabuf file is closed we now get: fput(file) -> __fput(file) -> f_op->release::dma_buf_file_release() -> dput() -> d_op->d_release::dma_buf_release() -> dmabuf->ops->release::ttm_prime_dmabuf_release() mutex_lock(&prime->mutex); if (prime->dma_buf == dma_buf) prime->dma_buf = NULL; mutex_unlock(&prime->mutex); Where we can see that prime->dma_buf is set to NULL. So when we have the following diagram: CPU1 CPU2 fput(file) -> __fput(file) -> f_op->release::dma_buf_file_release() -> dput() -> d_op->d_release::dma_buf_release() -> dmabuf->ops->release::ttm_prime_dmabuf_release() ttm_prime_handle_to_fd() mutex_lock_interruptible(&prime->mutex) dma_buf = prime->dma_buf dma_buf && get_dma_buf_unless_doomed(dma_buf) -> file_ref_get(dma_buf->file) mutex_unlock(&prime->mutex); mutex_lock(&prime->mutex); if (prime->dma_buf == dma_buf) prime->dma_buf = NULL; mutex_unlock(&prime->mutex); -> kmem_cache_free(file) The logic of the mechanism is the same as for epoll: sync with __fput() preventing the file from being freed. Here the synchronization happens through the ttm instance's prime->mutex. Basically, the lifetime of the dma_buf and the file are tighly coupled. Both (1) and (2) used to call atomic_inc_not_zero() to check whether the file has already been marked dead and then refuse to revive it. This is only safe because both (1) and (2) sync with __fput() and thus prevent kmem_cache_free() on the file being called and thus prevent the file from being immediately recycled due to SLAB_TYPESAFE_BY_RCU. Both (1) and (2) have been ported from atomic_inc_not_zero() to file_ref_get(). That means a file that is already in the process of being marked as FILE_REF_DEAD: file_ref_put() cnt = atomic_long_dec_return() -> __file_ref_put(cnt) if (cnt == FIlE_REF_NOREF) atomic_long_try_cmpxchg_release(cnt, FILE_REF_DEAD) can be revived again: CPU1 CPU2 file_ref_put() cnt = atomic_long_dec_return() -> __file_ref_put(cnt) if (cnt == FIlE_REF_NOREF) file_ref_get() // Brings reference back to FILE_REF_ONEREF atomic_long_add_negative() atomic_long_try_cmpxchg_release(cnt, FILE_REF_DEAD) This is fine and inherent to the file_ref_get()/file_ref_put() semantics. For both (1) and (2) this is safe because __fput() is prevented from making progress if file_ref_get() fails due to the aforementioned synchronization mechanisms. Two cases need to be considered that affect both (1) epoll and (2) ttm dmabuf: (i) fput()'s file_ref_put() and marks the file as FILE_REF_NOREF but before that fput() can mark the file as FILE_REF_DEAD someone manages to sneak in a file_ref_get() and brings the refcount back from FILE_REF_NOREF to FILE_REF_ONEREF. In that case the original fput() doesn't call __fput(). For epoll the poll will finish and for ttm dmabuf the file can be used again. For ttm dambuf this is actually an advantage because it avoids immediately allocating a new dmabuf object. CPU1 CPU2 file_ref_put() cnt = atomic_long_dec_return() -> __file_ref_put(cnt) if (cnt == FIlE_REF_NOREF) file_ref_get() // Brings reference back to FILE_REF_ONEREF atomic_long_add_negative() atomic_long_try_cmpxchg_release(cnt, FILE_REF_DEAD) (ii) fput()'s file_ref_put() marks the file FILE_REF_NOREF and also suceeds in actually marking it FILE_REF_DEAD and then calls into __fput() to free the file. When either (1) or (2) call file_ref_get() they fail as atomic_long_add_negative() will return true. At the same time, both (1) and (2) all file_ref_get() under mutexes that __fput() must also acquire preventing kmem_cache_free() from freeing the file. So while this might be treated as a change in semantics for (1) and (2) it really isn't. It if should end up causing issues this can be fixed by adding a helper that does something like: long cnt = atomic_long_read(&ref->refcnt); do { if (cnt < 0) return false; } while (!atomic_long_try_cmpxchg(&ref->refcnt, &cnt, cnt + 1)); return true; which would block FILE_REF_NOREF to FILE_REF_ONEREF transitions. - Jann correctly pointed out that kmem_cache_zalloc() cannot be used anymore once files have been ported to file_ref_t. The kmem_cache_zalloc() call will memset() the whole struct file to zero when it is reallocated. This will also set file->f_ref to zero which mens that a concurrent file_ref_get() can return true: CPU1 CPU2 __get_file_rcu() rcu_dereference_raw() close() [frees file] alloc_empty_file() kmem_cache_zalloc() [reallocates same file] memset(..., 0, ...) file_ref_get() [increments 0->1, returns true] init_file() file_ref_init(..., 1) [sets to 0] rcu_dereference_raw() fput() file_ref_put() [decrements 0->FILE_REF_NOREF, frees file] [UAF] causing a concurrent __get_file_rcu() call to acquire a reference to the file that is about to be reallocated and immediately freeing it on realizing that it has been recycled. This causes a UAF for the task that reallocated/recycled the file. This is prevented by switching from kmem_cache_zalloc() to kmem_cache_alloc() and initializing the fields manually. With file->f_ref initialized last. Note that a memset() also isn't guaranteed to atomically update an unsigned long so it's theoretically possible to see torn and therefore bogus counter values. Link: https://lore.kernel.org/r/20241007-brauner-file-rcuref-v2-3-387e24dc9163@kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-10-22epoll: Add synchronous wakeup support for ep_poll_callbackXuewen Yan1-1/+4
Now, the epoll only use wake_up() interface to wake up task. However, sometimes, there are epoll users which want to use the synchronous wakeup flag to hint the scheduler, such as Android binder driver. So add a wake_up_sync() define, and use the wake_up_sync() when the sync is true in ep_poll_callback(). Co-developed-by: Jing Xia <jing.xia@unisoc.com> Signed-off-by: Jing Xia <jing.xia@unisoc.com> Signed-off-by: Xuewen Yan <xuewen.yan@unisoc.com> Link: https://lore.kernel.org/r/20240426080548.8203-1-xuewen.yan@unisoc.com Tested-by: Brian Geffon <bgeffon@google.com> Reviewed-by: Brian Geffon <bgeffon@google.com> Reported-by: Benoit Lize <lizeb@google.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-10-22epoll: annotate racy checkChristian Brauner1-2/+4
Epoll relies on a racy fastpath check during __fput() in eventpoll_release() to avoid the hit of pointlessly acquiring a semaphore. Annotate that race by using WRITE_ONCE() and READ_ONCE(). Link: https://lore.kernel.org/r/66edfb3c.050a0220.3195df.001a.GAE@google.com Link: https://lore.kernel.org/r/20240925-fungieren-anbauen-79b334b00542@brauner Reviewed-by: Jan Kara <jack@suse.cz> Reported-by: syzbot+3b6b32dc50537a49bb4a@syzkaller.appspotmail.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-09-23Merge tag 'pull-stable-struct_fd' of ↵Linus Torvalds1-15/+15
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull 'struct fd' updates from Al Viro: "Just the 'struct fd' layout change, with conversion to accessor helpers" * tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: add struct fd constructors, get rid of __to_fd() struct fd: representation change introduce fd_file(), convert all accessors to it.
2024-08-30eventpoll: Annotate data-race of busy_poll_usecsMartin Kars