aboutsummaryrefslogtreecommitdiff
path: root/drivers/watchdog/softdog.c
diff options
context:
space:
mode:
authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /drivers/watchdog/softdog.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip
Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ...
Diffstat (limited to 'drivers/watchdog/softdog.c')
-rw-r--r--drivers/watchdog/softdog.c224
1 files changed, 224 insertions, 0 deletions
diff --git a/drivers/watchdog/softdog.c b/drivers/watchdog/softdog.c
new file mode 100644
index 000000000..7a1096265
--- /dev/null
+++ b/drivers/watchdog/softdog.c
@@ -0,0 +1,224 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * SoftDog: A Software Watchdog Device
+ *
+ * (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
+ * All Rights Reserved.
+ *
+ * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
+ * warranty for any of this software. This material is provided
+ * "AS-IS" and at no charge.
+ *
+ * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>
+ *
+ * Software only watchdog driver. Unlike its big brother the WDT501P
+ * driver this won't always recover a failed machine.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/hrtimer.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/kthread.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/reboot.h>
+#include <linux/types.h>
+#include <linux/watchdog.h>
+#include <linux/workqueue.h>
+
+#define TIMER_MARGIN 60 /* Default is 60 seconds */
+static unsigned int soft_margin = TIMER_MARGIN; /* in seconds */
+module_param(soft_margin, uint, 0);
+MODULE_PARM_DESC(soft_margin,
+ "Watchdog soft_margin in seconds. (0 < soft_margin < 65536, default="
+ __MODULE_STRING(TIMER_MARGIN) ")");
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout,
+ "Watchdog cannot be stopped once started (default="
+ __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+static int soft_noboot;
+module_param(soft_noboot, int, 0);
+MODULE_PARM_DESC(soft_noboot,
+ "Softdog action, set to 1 to ignore reboots, 0 to reboot (default=0)");
+
+static int soft_panic;
+module_param(soft_panic, int, 0);
+MODULE_PARM_DESC(soft_panic,
+ "Softdog action, set to 1 to panic, 0 to reboot (default=0)");
+
+static char *soft_reboot_cmd;
+module_param(soft_reboot_cmd, charp, 0000);
+MODULE_PARM_DESC(soft_reboot_cmd,
+ "Set reboot command. Emergency reboot takes place if unset");
+
+static bool soft_active_on_boot;
+module_param(soft_active_on_boot, bool, 0000);
+MODULE_PARM_DESC(soft_active_on_boot,
+ "Set to true to active Softdog on boot (default=false)");
+
+static struct hrtimer softdog_ticktock;
+static struct hrtimer softdog_preticktock;
+
+static int reboot_kthread_fn(void *data)
+{
+ kernel_restart(soft_reboot_cmd);
+ return -EPERM; /* Should not reach here */
+}
+
+static void reboot_work_fn(struct work_struct *unused)
+{
+ kthread_run(reboot_kthread_fn, NULL, "softdog_reboot");
+}
+
+static enum hrtimer_restart softdog_fire(struct hrtimer *timer)
+{
+ static bool soft_reboot_fired;
+
+ module_put(THIS_MODULE);
+ if (soft_noboot) {
+ pr_crit("Triggered - Reboot ignored\n");
+ } else if (soft_panic) {
+ pr_crit("Initiating panic\n");
+ panic("Software Watchdog Timer expired");
+ } else {
+ pr_crit("Initiating system reboot\n");
+ if (!soft_reboot_fired && soft_reboot_cmd != NULL) {
+ static DECLARE_WORK(reboot_work, reboot_work_fn);
+ /*
+ * The 'kernel_restart' is a 'might-sleep' operation.
+ * Also, executing it in system-wide workqueues blocks
+ * any driver from using the same workqueue in its
+ * shutdown callback function. Thus, we should execute
+ * the 'kernel_restart' in a standalone kernel thread.
+ * But since starting a kernel thread is also a
+ * 'might-sleep' operation, so the 'reboot_work' is
+ * required as a launcher of the kernel thread.
+ *
+ * After request the reboot, restart the timer to
+ * schedule an 'emergency_restart' reboot after
+ * 'TIMER_MARGIN' seconds. It's because if the softdog
+ * hangs, it might be because of scheduling issues. And
+ * if that is the case, both 'schedule_work' and
+ * 'kernel_restart' may possibly be malfunctional at the
+ * same time.
+ */
+ soft_reboot_fired = true;
+ schedule_work(&reboot_work);
+ hrtimer_add_expires_ns(timer,
+ (u64)TIMER_MARGIN * NSEC_PER_SEC);
+
+ return HRTIMER_RESTART;
+ }
+ emergency_restart();
+ pr_crit("Reboot didn't ?????\n");
+ }
+
+ return HRTIMER_NORESTART;
+}
+
+static struct watchdog_device softdog_dev;
+
+static enum hrtimer_restart softdog_pretimeout(struct hrtimer *timer)
+{
+ watchdog_notify_pretimeout(&softdog_dev);
+
+ return HRTIMER_NORESTART;
+}
+
+static int softdog_ping(struct watchdog_device *w)
+{
+ if (!hrtimer_active(&softdog_ticktock))
+ __module_get(THIS_MODULE);
+ hrtimer_start(&softdog_ticktock, ktime_set(w->timeout, 0),
+ HRTIMER_MODE_REL);
+
+ if (IS_ENABLED(CONFIG_SOFT_WATCHDOG_PRETIMEOUT)) {
+ if (w->pretimeout)
+ hrtimer_start(&softdog_preticktock,
+ ktime_set(w->timeout - w->pretimeout, 0),
+ HRTIMER_MODE_REL);
+ else
+ hrtimer_cancel(&softdog_preticktock);
+ }
+
+ return 0;
+}
+
+static int softdog_stop(struct watchdog_device *w)
+{
+ if (hrtimer_cancel(&softdog_ticktock))
+ module_put(THIS_MODULE);
+
+ if (IS_ENABLED(CONFIG_SOFT_WATCHDOG_PRETIMEOUT))
+ hrtimer_cancel(&softdog_preticktock);
+
+ return 0;
+}
+
+static struct watchdog_info softdog_info = {
+ .identity = "Software Watchdog",
+ .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+};
+
+static const struct watchdog_ops softdog_ops = {
+ .owner = THIS_MODULE,
+ .start = softdog_ping,
+ .stop = softdog_stop,
+};
+
+static struct watchdog_device softdog_dev = {
+ .info = &softdog_info,
+ .ops = &softdog_ops,
+ .min_timeout = 1,
+ .max_timeout = 65535,
+ .timeout = TIMER_MARGIN,
+};
+
+static int __init softdog_init(void)
+{
+ int ret;
+
+ watchdog_init_timeout(&softdog_dev, soft_margin, NULL);
+ watchdog_set_nowayout(&softdog_dev, nowayout);
+ watchdog_stop_on_reboot(&softdog_dev);
+
+ hrtimer_init(&softdog_ticktock, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ softdog_ticktock.function = softdog_fire;
+
+ if (IS_ENABLED(CONFIG_SOFT_WATCHDOG_PRETIMEOUT)) {
+ softdog_info.options |= WDIOF_PRETIMEOUT;
+ hrtimer_init(&softdog_preticktock, CLOCK_MONOTONIC,
+ HRTIMER_MODE_REL);
+ softdog_preticktock.function = softdog_pretimeout;
+ }
+
+ if (soft_active_on_boot)
+ softdog_ping(&softdog_dev);
+
+ ret = watchdog_register_device(&softdog_dev);
+ if (ret)
+ return ret;
+
+ pr_info("initialized. soft_noboot=%d soft_margin=%d sec soft_panic=%d (nowayout=%d)\n",
+ soft_noboot, softdog_dev.timeout, soft_panic, nowayout);
+ pr_info(" soft_reboot_cmd=%s soft_active_on_boot=%d\n",
+ soft_reboot_cmd ?: "<not set>", soft_active_on_boot);
+
+ return 0;
+}
+module_init(softdog_init);
+
+static void __exit softdog_exit(void)
+{
+ watchdog_unregister_device(&softdog_dev);
+}
+module_exit(softdog_exit);
+
+MODULE_AUTHOR("Alan Cox");
+MODULE_DESCRIPTION("Software Watchdog Device Driver");
+MODULE_LICENSE("GPL");