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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/tty/serial/kgdb_nmi.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
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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 '')
-rw-r--r--drivers/tty/serial/kgdb_nmi.c380
1 files changed, 380 insertions, 0 deletions
diff --git a/drivers/tty/serial/kgdb_nmi.c b/drivers/tty/serial/kgdb_nmi.c
new file mode 100644
index 000000000..55c3c9db7
--- /dev/null
+++ b/drivers/tty/serial/kgdb_nmi.c
@@ -0,0 +1,380 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KGDB NMI serial console
+ *
+ * Copyright 2010 Google, Inc.
+ * Arve Hjønnevåg <arve@android.com>
+ * Colin Cross <ccross@android.com>
+ * Copyright 2012 Linaro Ltd.
+ * Anton Vorontsov <anton.vorontsov@linaro.org>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/compiler.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/atomic.h>
+#include <linux/console.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/serial_core.h>
+#include <linux/interrupt.h>
+#include <linux/hrtimer.h>
+#include <linux/tick.h>
+#include <linux/kfifo.h>
+#include <linux/kgdb.h>
+#include <linux/kdb.h>
+
+static int kgdb_nmi_knock = 1;
+module_param_named(knock, kgdb_nmi_knock, int, 0600);
+MODULE_PARM_DESC(knock, "if set to 1 (default), the special '$3#33' command " \
+ "must be used to enter the debugger; when set to 0, " \
+ "hitting return key is enough to enter the debugger; " \
+ "when set to -1, the debugger is entered immediately " \
+ "upon NMI");
+
+static char *kgdb_nmi_magic = "$3#33";
+module_param_named(magic, kgdb_nmi_magic, charp, 0600);
+MODULE_PARM_DESC(magic, "magic sequence to enter NMI debugger (default $3#33)");
+
+static atomic_t kgdb_nmi_num_readers = ATOMIC_INIT(0);
+
+static int kgdb_nmi_console_setup(struct console *co, char *options)
+{
+ arch_kgdb_ops.enable_nmi(1);
+
+ /* The NMI console uses the dbg_io_ops to issue console messages. To
+ * avoid duplicate messages during kdb sessions we must inform kdb's
+ * I/O utilities that messages sent to the console will automatically
+ * be displayed on the dbg_io.
+ */
+ dbg_io_ops->cons = co;
+
+ return 0;
+}
+
+static void kgdb_nmi_console_write(struct console *co, const char *s, uint c)
+{
+ int i;
+
+ for (i = 0; i < c; i++)
+ dbg_io_ops->write_char(s[i]);
+}
+
+static struct tty_driver *kgdb_nmi_tty_driver;
+
+static struct tty_driver *kgdb_nmi_console_device(struct console *co, int *idx)
+{
+ *idx = co->index;
+ return kgdb_nmi_tty_driver;
+}
+
+static struct console kgdb_nmi_console = {
+ .name = "ttyNMI",
+ .setup = kgdb_nmi_console_setup,
+ .write = kgdb_nmi_console_write,
+ .device = kgdb_nmi_console_device,
+ .flags = CON_PRINTBUFFER | CON_ANYTIME,
+ .index = -1,
+};
+
+/*
+ * This is usually the maximum rate on debug ports. We make fifo large enough
+ * to make copy-pasting to the terminal usable.
+ */
+#define KGDB_NMI_BAUD 115200
+#define KGDB_NMI_FIFO_SIZE roundup_pow_of_two(KGDB_NMI_BAUD / 8 / HZ)
+
+struct kgdb_nmi_tty_priv {
+ struct tty_port port;
+ struct timer_list timer;
+ STRUCT_KFIFO(char, KGDB_NMI_FIFO_SIZE) fifo;
+};
+
+static struct tty_port *kgdb_nmi_port;
+
+static void kgdb_tty_recv(int ch)
+{
+ struct kgdb_nmi_tty_priv *priv;
+ char c = ch;
+
+ if (!kgdb_nmi_port || ch < 0)
+ return;
+ /*
+ * Can't use port->tty->driver_data as tty might be not there. Timer
+ * will check for tty and will get the ref, but here we don't have to
+ * do that, and actually, we can't: we're in NMI context, no locks are
+ * possible.
+ */
+ priv = container_of(kgdb_nmi_port, struct kgdb_nmi_tty_priv, port);
+ kfifo_in(&priv->fifo, &c, 1);
+}
+
+static int kgdb_nmi_poll_one_knock(void)
+{
+ static int n;
+ int c;
+ const char *magic = kgdb_nmi_magic;
+ size_t m = strlen(magic);
+ bool printch = false;
+
+ c = dbg_io_ops->read_char();
+ if (c == NO_POLL_CHAR)
+ return c;
+
+ if (!kgdb_nmi_knock && (c == '\r' || c == '\n')) {
+ return 1;
+ } else if (c == magic[n]) {
+ n = (n + 1) % m;
+ if (!n)
+ return 1;
+ printch = true;
+ } else {
+ n = 0;
+ }
+
+ if (atomic_read(&kgdb_nmi_num_readers)) {
+ kgdb_tty_recv(c);
+ return 0;
+ }
+
+ if (printch) {
+ kdb_printf("%c", c);
+ return 0;
+ }
+
+ kdb_printf("\r%s %s to enter the debugger> %*s",
+ kgdb_nmi_knock ? "Type" : "Hit",
+ kgdb_nmi_knock ? magic : "<return>", (int)m, "");
+ while (m--)
+ kdb_printf("\b");
+ return 0;
+}
+
+/**
+ * kgdb_nmi_poll_knock - Check if it is time to enter the debugger
+ *
+ * "Serial ports are often noisy, especially when muxed over another port (we
+ * often use serial over the headset connector). Noise on the async command
+ * line just causes characters that are ignored, on a command line that blocked
+ * execution noise would be catastrophic." -- Colin Cross
+ *
+ * So, this function implements KGDB/KDB knocking on the serial line: we won't
+ * enter the debugger until we receive a known magic phrase (which is actually
+ * "$3#33", known as "escape to KDB" command. There is also a relaxed variant
+ * of knocking, i.e. just pressing the return key is enough to enter the
+ * debugger. And if knocking is disabled, the function always returns 1.
+ */
+bool kgdb_nmi_poll_knock(void)
+{
+ if (kgdb_nmi_knock < 0)
+ return true;
+
+ while (1) {
+ int ret;
+
+ ret = kgdb_nmi_poll_one_knock();
+ if (ret == NO_POLL_CHAR)
+ return false;
+ else if (ret == 1)
+ break;
+ }
+ return true;
+}
+
+/*
+ * The tasklet is cheap, it does not cause wakeups when reschedules itself,
+ * instead it waits for the next tick.
+ */
+static void kgdb_nmi_tty_receiver(struct timer_list *t)
+{
+ struct kgdb_nmi_tty_priv *priv = from_timer(priv, t, timer);
+ char ch;
+
+ priv->timer.expires = jiffies + (HZ/100);
+ add_timer(&priv->timer);
+
+ if (likely(!atomic_read(&kgdb_nmi_num_readers) ||
+ !kfifo_len(&priv->fifo)))
+ return;
+
+ while (kfifo_out(&priv->fifo, &ch, 1))
+ tty_insert_flip_char(&priv->port, ch, TTY_NORMAL);
+ tty_flip_buffer_push(&priv->port);
+}
+
+static int kgdb_nmi_tty_activate(struct tty_port *port, struct tty_struct *tty)
+{
+ struct kgdb_nmi_tty_priv *priv =
+ container_of(port, struct kgdb_nmi_tty_priv, port);
+
+ kgdb_nmi_port = port;
+ priv->timer.expires = jiffies + (HZ/100);
+ add_timer(&priv->timer);
+
+ return 0;
+}
+
+static void kgdb_nmi_tty_shutdown(struct tty_port *port)
+{
+ struct kgdb_nmi_tty_priv *priv =
+ container_of(port, struct kgdb_nmi_tty_priv, port);
+
+ del_timer(&priv->timer);
+ kgdb_nmi_port = NULL;
+}
+
+static const struct tty_port_operations kgdb_nmi_tty_port_ops = {
+ .activate = kgdb_nmi_tty_activate,
+ .shutdown = kgdb_nmi_tty_shutdown,
+};
+
+static int kgdb_nmi_tty_install(struct tty_driver *drv, struct tty_struct *tty)
+{
+ struct kgdb_nmi_tty_priv *priv;
+ int ret;
+
+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ INIT_KFIFO(priv->fifo);
+ timer_setup(&priv->timer, kgdb_nmi_tty_receiver, 0);
+ tty_port_init(&priv->port);
+ priv->port.ops = &kgdb_nmi_tty_port_ops;
+ tty->driver_data = priv;
+
+ ret = tty_port_install(&priv->port, drv, tty);
+ if (ret) {
+ pr_err("%s: can't install tty port: %d\n", __func__, ret);
+ goto err;
+ }
+ return 0;
+err:
+ tty_port_destroy(&priv->port);
+ kfree(priv);
+ return ret;
+}
+
+static void kgdb_nmi_tty_cleanup(struct tty_struct *tty)
+{
+ struct kgdb_nmi_tty_priv *priv = tty->driver_data;
+
+ tty->driver_data = NULL;
+ tty_port_destroy(&priv->port);
+ kfree(priv);
+}
+
+static int kgdb_nmi_tty_open(struct tty_struct *tty, struct file *file)
+{
+ struct kgdb_nmi_tty_priv *priv = tty->driver_data;
+ unsigned int mode = file->f_flags & O_ACCMODE;
+ int ret;
+
+ ret = tty_port_open(&priv->port, tty, file);
+ if (!ret && (mode == O_RDONLY || mode == O_RDWR))
+ atomic_inc(&kgdb_nmi_num_readers);
+
+ return ret;
+}
+
+static void kgdb_nmi_tty_close(struct tty_struct *tty, struct file *file)
+{
+ struct kgdb_nmi_tty_priv *priv = tty->driver_data;
+ unsigned int mode = file->f_flags & O_ACCMODE;
+
+ if (mode == O_RDONLY || mode == O_RDWR)
+ atomic_dec(&kgdb_nmi_num_readers);
+
+ tty_port_close(&priv->port, tty, file);
+}
+
+static void kgdb_nmi_tty_hangup(struct tty_struct *tty)
+{
+ struct kgdb_nmi_tty_priv *priv = tty->driver_data;
+
+ tty_port_hangup(&priv->port);
+}
+
+static unsigned int kgdb_nmi_tty_write_room(struct tty_struct *tty)
+{
+ /* Actually, we can handle any amount as we use polled writes. */
+ return 2048;
+}
+
+static int kgdb_nmi_tty_write(struct tty_struct *tty, const unchar *buf, int c)
+{
+ int i;
+
+ for (i = 0; i < c; i++)
+ dbg_io_ops->write_char(buf[i]);
+ return c;
+}
+
+static const struct tty_operations kgdb_nmi_tty_ops = {
+ .open = kgdb_nmi_tty_open,
+ .close = kgdb_nmi_tty_close,
+ .install = kgdb_nmi_tty_install,
+ .cleanup = kgdb_nmi_tty_cleanup,
+ .hangup = kgdb_nmi_tty_hangup,
+ .write_room = kgdb_nmi_tty_write_room,
+ .write = kgdb_nmi_tty_write,
+};
+
+int kgdb_register_nmi_console(void)
+{
+ int ret;
+
+ if (!arch_kgdb_ops.enable_nmi)
+ return 0;
+
+ kgdb_nmi_tty_driver = tty_alloc_driver(1, TTY_DRIVER_REAL_RAW);
+ if (IS_ERR(kgdb_nmi_tty_driver)) {
+ pr_err("%s: cannot allocate tty\n", __func__);
+ return PTR_ERR(kgdb_nmi_tty_driver);
+ }
+ kgdb_nmi_tty_driver->driver_name = "ttyNMI";
+ kgdb_nmi_tty_driver->name = "ttyNMI";
+ kgdb_nmi_tty_driver->num = 1;
+ kgdb_nmi_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
+ kgdb_nmi_tty_driver->subtype = SERIAL_TYPE_NORMAL;
+ kgdb_nmi_tty_driver->init_termios = tty_std_termios;
+ tty_termios_encode_baud_rate(&kgdb_nmi_tty_driver->init_termios,
+ KGDB_NMI_BAUD, KGDB_NMI_BAUD);
+ tty_set_operations(kgdb_nmi_tty_driver, &kgdb_nmi_tty_ops);
+
+ ret = tty_register_driver(kgdb_nmi_tty_driver);
+ if (ret) {
+ pr_err("%s: can't register tty driver: %d\n", __func__, ret);
+ goto err_drv_reg;
+ }
+
+ register_console(&kgdb_nmi_console);
+
+ return 0;
+err_drv_reg:
+ tty_driver_kref_put(kgdb_nmi_tty_driver);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(kgdb_register_nmi_console);
+
+int kgdb_unregister_nmi_console(void)
+{
+ int ret;
+
+ if (!arch_kgdb_ops.enable_nmi)
+ return 0;
+ arch_kgdb_ops.enable_nmi(0);
+
+ ret = unregister_console(&kgdb_nmi_console);
+ if (ret)
+ return ret;
+
+ tty_unregister_driver(kgdb_nmi_tty_driver);
+ tty_driver_kref_put(kgdb_nmi_tty_driver);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(kgdb_unregister_nmi_console);