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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 /kernel/trace/trace_irqsoff.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 'kernel/trace/trace_irqsoff.c')
-rw-r--r--kernel/trace/trace_irqsoff.c751
1 files changed, 751 insertions, 0 deletions
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
new file mode 100644
index 000000000..590b3d51a
--- /dev/null
+++ b/kernel/trace/trace_irqsoff.c
@@ -0,0 +1,751 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * trace irqs off critical timings
+ *
+ * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
+ * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
+ *
+ * From code in the latency_tracer, that is:
+ *
+ * Copyright (C) 2004-2006 Ingo Molnar
+ * Copyright (C) 2004 Nadia Yvette Chambers
+ */
+#include <linux/kallsyms.h>
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/ftrace.h>
+#include <linux/kprobes.h>
+
+#include "trace.h"
+
+#include <trace/events/preemptirq.h>
+
+#if defined(CONFIG_IRQSOFF_TRACER) || defined(CONFIG_PREEMPT_TRACER)
+static struct trace_array *irqsoff_trace __read_mostly;
+static int tracer_enabled __read_mostly;
+
+static DEFINE_PER_CPU(int, tracing_cpu);
+
+static DEFINE_RAW_SPINLOCK(max_trace_lock);
+
+enum {
+ TRACER_IRQS_OFF = (1 << 1),
+ TRACER_PREEMPT_OFF = (1 << 2),
+};
+
+static int trace_type __read_mostly;
+
+static int save_flags;
+
+static void stop_irqsoff_tracer(struct trace_array *tr, int graph);
+static int start_irqsoff_tracer(struct trace_array *tr, int graph);
+
+#ifdef CONFIG_PREEMPT_TRACER
+static inline int
+preempt_trace(int pc)
+{
+ return ((trace_type & TRACER_PREEMPT_OFF) && pc);
+}
+#else
+# define preempt_trace(pc) (0)
+#endif
+
+#ifdef CONFIG_IRQSOFF_TRACER
+static inline int
+irq_trace(void)
+{
+ return ((trace_type & TRACER_IRQS_OFF) &&
+ irqs_disabled());
+}
+#else
+# define irq_trace() (0)
+#endif
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+static int irqsoff_display_graph(struct trace_array *tr, int set);
+# define is_graph(tr) ((tr)->trace_flags & TRACE_ITER_DISPLAY_GRAPH)
+#else
+static inline int irqsoff_display_graph(struct trace_array *tr, int set)
+{
+ return -EINVAL;
+}
+# define is_graph(tr) false
+#endif
+
+/*
+ * Sequence count - we record it when starting a measurement and
+ * skip the latency if the sequence has changed - some other section
+ * did a maximum and could disturb our measurement with serial console
+ * printouts, etc. Truly coinciding maximum latencies should be rare
+ * and what happens together happens separately as well, so this doesn't
+ * decrease the validity of the maximum found:
+ */
+static __cacheline_aligned_in_smp unsigned long max_sequence;
+
+#ifdef CONFIG_FUNCTION_TRACER
+/*
+ * Prologue for the preempt and irqs off function tracers.
+ *
+ * Returns 1 if it is OK to continue, and data->disabled is
+ * incremented.
+ * 0 if the trace is to be ignored, and data->disabled
+ * is kept the same.
+ *
+ * Note, this function is also used outside this ifdef but
+ * inside the #ifdef of the function graph tracer below.
+ * This is OK, since the function graph tracer is
+ * dependent on the function tracer.
+ */
+static int func_prolog_dec(struct trace_array *tr,
+ struct trace_array_cpu **data,
+ unsigned long *flags)
+{
+ long disabled;
+ int cpu;
+
+ /*
+ * Does not matter if we preempt. We test the flags
+ * afterward, to see if irqs are disabled or not.
+ * If we preempt and get a false positive, the flags
+ * test will fail.
+ */
+ cpu = raw_smp_processor_id();
+ if (likely(!per_cpu(tracing_cpu, cpu)))
+ return 0;
+
+ local_save_flags(*flags);
+ /*
+ * Slight chance to get a false positive on tracing_cpu,
+ * although I'm starting to think there isn't a chance.
+ * Leave this for now just to be paranoid.
+ */
+ if (!irqs_disabled_flags(*flags) && !preempt_count())
+ return 0;
+
+ *data = per_cpu_ptr(tr->array_buffer.data, cpu);
+ disabled = atomic_inc_return(&(*data)->disabled);
+
+ if (likely(disabled == 1))
+ return 1;
+
+ atomic_dec(&(*data)->disabled);
+
+ return 0;
+}
+
+/*
+ * irqsoff uses its own tracer function to keep the overhead down:
+ */
+static void
+irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *op, struct ftrace_regs *fregs)
+{
+ struct trace_array *tr = irqsoff_trace;
+ struct trace_array_cpu *data;
+ unsigned long flags;
+ unsigned int trace_ctx;
+
+ if (!func_prolog_dec(tr, &data, &flags))
+ return;
+
+ trace_ctx = tracing_gen_ctx_flags(flags);
+
+ trace_function(tr, ip, parent_ip, trace_ctx);
+
+ atomic_dec(&data->disabled);
+}
+#endif /* CONFIG_FUNCTION_TRACER */
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+static int irqsoff_display_graph(struct trace_array *tr, int set)
+{
+ int cpu;
+
+ if (!(is_graph(tr) ^ set))
+ return 0;
+
+ stop_irqsoff_tracer(irqsoff_trace, !set);
+
+ for_each_possible_cpu(cpu)
+ per_cpu(tracing_cpu, cpu) = 0;
+
+ tr->max_latency = 0;
+ tracing_reset_online_cpus(&irqsoff_trace->array_buffer);
+
+ return start_irqsoff_tracer(irqsoff_trace, set);
+}
+
+static int irqsoff_graph_entry(struct ftrace_graph_ent *trace)
+{
+ struct trace_array *tr = irqsoff_trace;
+ struct trace_array_cpu *data;
+ unsigned long flags;
+ unsigned int trace_ctx;
+ int ret;
+
+ if (ftrace_graph_ignore_func(trace))
+ return 0;
+ /*
+ * Do not trace a function if it's filtered by set_graph_notrace.
+ * Make the index of ret stack negative to indicate that it should
+ * ignore further functions. But it needs its own ret stack entry
+ * to recover the original index in order to continue tracing after
+ * returning from the function.
+ */
+ if (ftrace_graph_notrace_addr(trace->func))
+ return 1;
+
+ if (!func_prolog_dec(tr, &data, &flags))
+ return 0;
+
+ trace_ctx = tracing_gen_ctx_flags(flags);
+ ret = __trace_graph_entry(tr, trace, trace_ctx);
+ atomic_dec(&data->disabled);
+
+ return ret;
+}
+
+static void irqsoff_graph_return(struct ftrace_graph_ret *trace)
+{
+ struct trace_array *tr = irqsoff_trace;
+ struct trace_array_cpu *data;
+ unsigned long flags;
+ unsigned int trace_ctx;
+
+ ftrace_graph_addr_finish(trace);
+
+ if (!func_prolog_dec(tr, &data, &flags))
+ return;
+
+ trace_ctx = tracing_gen_ctx_flags(flags);
+ __trace_graph_return(tr, trace, trace_ctx);
+ atomic_dec(&data->disabled);
+}
+
+static struct fgraph_ops fgraph_ops = {
+ .entryfunc = &irqsoff_graph_entry,
+ .retfunc = &irqsoff_graph_return,
+};
+
+static void irqsoff_trace_open(struct trace_iterator *iter)
+{
+ if (is_graph(iter->tr))
+ graph_trace_open(iter);
+
+}
+
+static void irqsoff_trace_close(struct trace_iterator *iter)
+{
+ if (iter->private)
+ graph_trace_close(iter);
+}
+
+#define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_CPU | \
+ TRACE_GRAPH_PRINT_PROC | \
+ TRACE_GRAPH_PRINT_REL_TIME | \
+ TRACE_GRAPH_PRINT_DURATION)
+
+static enum print_line_t irqsoff_print_line(struct trace_iterator *iter)
+{
+ /*
+ * In graph mode call the graph tracer output function,
+ * otherwise go with the TRACE_FN event handler
+ */
+ if (is_graph(iter->tr))
+ return print_graph_function_flags(iter, GRAPH_TRACER_FLAGS);
+
+ return TRACE_TYPE_UNHANDLED;
+}
+
+static void irqsoff_print_header(struct seq_file *s)
+{
+ struct trace_array *tr = irqsoff_trace;
+
+ if (is_graph(tr))
+ print_graph_headers_flags(s, GRAPH_TRACER_FLAGS);
+ else
+ trace_default_header(s);
+}
+
+static void
+__trace_function(struct trace_array *tr,
+ unsigned long ip, unsigned long parent_ip,
+ unsigned int trace_ctx)
+{
+ if (is_graph(tr))
+ trace_graph_function(tr, ip, parent_ip, trace_ctx);
+ else
+ trace_function(tr, ip, parent_ip, trace_ctx);
+}
+
+#else
+#define __trace_function trace_function
+
+static enum print_line_t irqsoff_print_line(struct trace_iterator *iter)
+{
+ return TRACE_TYPE_UNHANDLED;
+}
+
+static void irqsoff_trace_open(struct trace_iterator *iter) { }
+static void irqsoff_trace_close(struct trace_iterator *iter) { }
+
+#ifdef CONFIG_FUNCTION_TRACER
+static void irqsoff_print_header(struct seq_file *s)
+{
+ trace_default_header(s);
+}
+#else
+static void irqsoff_print_header(struct seq_file *s)
+{
+ trace_latency_header(s);
+}
+#endif /* CONFIG_FUNCTION_TRACER */
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+/*
+ * Should this new latency be reported/recorded?
+ */
+static bool report_latency(struct trace_array *tr, u64 delta)
+{
+ if (tracing_thresh) {
+ if (delta < tracing_thresh)
+ return false;
+ } else {
+ if (delta <= tr->max_latency)
+ return false;
+ }
+ return true;
+}
+
+static void
+check_critical_timing(struct trace_array *tr,
+ struct trace_array_cpu *data,
+ unsigned long parent_ip,
+ int cpu)
+{
+ u64 T0, T1, delta;
+ unsigned long flags;
+ unsigned int trace_ctx;
+
+ T0 = data->preempt_timestamp;
+ T1 = ftrace_now(cpu);
+ delta = T1-T0;
+
+ trace_ctx = tracing_gen_ctx();
+
+ if (!report_latency(tr, delta))
+ goto out;
+
+ raw_spin_lock_irqsave(&max_trace_lock, flags);
+
+ /* check if we are still the max latency */
+ if (!report_latency(tr, delta))
+ goto out_unlock;
+
+ __trace_function(tr, CALLER_ADDR0, parent_ip, trace_ctx);
+ /* Skip 5 functions to get to the irq/preempt enable function */
+ __trace_stack(tr, trace_ctx, 5);
+
+ if (data->critical_sequence != max_sequence)
+ goto out_unlock;
+
+ data->critical_end = parent_ip;
+
+ if (likely(!is_tracing_stopped())) {
+ tr->max_latency = delta;
+ update_max_tr_single(tr, current, cpu);
+ }
+
+ max_sequence++;
+
+out_unlock:
+ raw_spin_unlock_irqrestore(&max_trace_lock, flags);
+
+out:
+ data->critical_sequence = max_sequence;
+ data->preempt_timestamp = ftrace_now(cpu);
+ __trace_function(tr, CALLER_ADDR0, parent_ip, trace_ctx);
+}
+
+static nokprobe_inline void
+start_critical_timing(unsigned long ip, unsigned long parent_ip)
+{
+ int cpu;
+ struct trace_array *tr = irqsoff_trace;
+ struct trace_array_cpu *data;
+
+ if (!tracer_enabled || !tracing_is_enabled())
+ return;
+
+ cpu = raw_smp_processor_id();
+
+ if (per_cpu(tracing_cpu, cpu))
+ return;
+
+ data = per_cpu_ptr(tr->array_buffer.data, cpu);
+
+ if (unlikely(!data) || atomic_read(&data->disabled))
+ return;
+
+ atomic_inc(&data->disabled);
+
+ data->critical_sequence = max_sequence;
+ data->preempt_timestamp = ftrace_now(cpu);
+ data->critical_start = parent_ip ? : ip;
+
+ __trace_function(tr, ip, parent_ip, tracing_gen_ctx());
+
+ per_cpu(tracing_cpu, cpu) = 1;
+
+ atomic_dec(&data->disabled);
+}
+
+static nokprobe_inline void
+stop_critical_timing(unsigned long ip, unsigned long parent_ip)
+{
+ int cpu;
+ struct trace_array *tr = irqsoff_trace;
+ struct trace_array_cpu *data;
+ unsigned int trace_ctx;
+
+ cpu = raw_smp_processor_id();
+ /* Always clear the tracing cpu on stopping the trace */
+ if (unlikely(per_cpu(tracing_cpu, cpu)))
+ per_cpu(tracing_cpu, cpu) = 0;
+ else
+ return;
+
+ if (!tracer_enabled || !tracing_is_enabled())
+ return;
+
+ data = per_cpu_ptr(tr->array_buffer.data, cpu);
+
+ if (unlikely(!data) ||
+ !data->critical_start || atomic_read(&data->disabled))
+ return;
+
+ atomic_inc(&data->disabled);
+
+ trace_ctx = tracing_gen_ctx();
+ __trace_function(tr, ip, parent_ip, trace_ctx);
+ check_critical_timing(tr, data, parent_ip ? : ip, cpu);
+ data->critical_start = 0;
+ atomic_dec(&data->disabled);
+}
+
+/* start and stop critical timings used to for stoppage (in idle) */
+void start_critical_timings(void)
+{
+ if (preempt_trace(preempt_count()) || irq_trace())
+ start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
+}
+EXPORT_SYMBOL_GPL(start_critical_timings);
+NOKPROBE_SYMBOL(start_critical_timings);
+
+void stop_critical_timings(void)
+{
+ if (preempt_trace(preempt_count()) || irq_trace())
+ stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
+}
+EXPORT_SYMBOL_GPL(stop_critical_timings);
+NOKPROBE_SYMBOL(stop_critical_timings);
+
+#ifdef CONFIG_FUNCTION_TRACER
+static bool function_enabled;
+
+static int register_irqsoff_function(struct trace_array *tr, int graph, int set)
+{
+ int ret;
+
+ /* 'set' is set if TRACE_ITER_FUNCTION is about to be set */
+ if (function_enabled || (!set && !(tr->trace_flags & TRACE_ITER_FUNCTION)))
+ return 0;
+
+ if (graph)
+ ret = register_ftrace_graph(&fgraph_ops);
+ else
+ ret = register_ftrace_function(tr->ops);
+
+ if (!ret)
+ function_enabled = true;
+
+ return ret;
+}
+
+static void unregister_irqsoff_function(struct trace_array *tr, int graph)
+{
+ if (!function_enabled)
+ return;
+
+ if (graph)
+ unregister_ftrace_graph(&fgraph_ops);
+ else
+ unregister_ftrace_function(tr->ops);
+
+ function_enabled = false;
+}
+
+static int irqsoff_function_set(struct trace_array *tr, u32 mask, int set)
+{
+ if (!(mask & TRACE_ITER_FUNCTION))
+ return 0;
+
+ if (set)
+ register_irqsoff_function(tr, is_graph(tr), 1);
+ else
+ unregister_irqsoff_function(tr, is_graph(tr));
+ return 1;
+}
+#else
+static int register_irqsoff_function(struct trace_array *tr, int graph, int set)
+{
+ return 0;
+}
+static void unregister_irqsoff_function(struct trace_array *tr, int graph) { }
+static inline int irqsoff_function_set(struct trace_array *tr, u32 mask, int set)
+{
+ return 0;
+}
+#endif /* CONFIG_FUNCTION_TRACER */
+
+static int irqsoff_flag_changed(struct trace_array *tr, u32 mask, int set)
+{
+ struct tracer *tracer = tr->current_trace;
+
+ if (irqsoff_function_set(tr, mask, set))
+ return 0;
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ if (mask & TRACE_ITER_DISPLAY_GRAPH)
+ return irqsoff_display_graph(tr, set);
+#endif
+
+ return trace_keep_overwrite(tracer, mask, set);
+}
+
+static int start_irqsoff_tracer(struct trace_array *tr, int graph)
+{
+ int ret;
+
+ ret = register_irqsoff_function(tr, graph, 0);
+
+ if (!ret && tracing_is_enabled())
+ tracer_enabled = 1;
+ else
+ tracer_enabled = 0;
+
+ return ret;
+}
+
+static void stop_irqsoff_tracer(struct trace_array *tr, int graph)
+{
+ tracer_enabled = 0;
+
+ unregister_irqsoff_function(tr, graph);
+}
+
+static bool irqsoff_busy;
+
+static int __irqsoff_tracer_init(struct trace_array *tr)
+{
+ if (irqsoff_busy)
+ return -EBUSY;
+
+ save_flags = tr->trace_flags;
+
+ /* non overwrite screws up the latency tracers */
+ set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1);
+ set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1);
+ /* without pause, we will produce garbage if another latency occurs */
+ set_tracer_flag(tr, TRACE_ITER_PAUSE_ON_TRACE, 1);
+
+ tr->max_latency = 0;
+ irqsoff_trace = tr;
+ /* make sure that the tracer is visible */
+ smp_wmb();
+
+ ftrace_init_array_ops(tr, irqsoff_tracer_call);
+
+ /* Only toplevel instance supports graph tracing */
+ if (start_irqsoff_tracer(tr, (tr->flags & TRACE_ARRAY_FL_GLOBAL &&
+ is_graph(tr))))
+ printk(KERN_ERR "failed to start irqsoff tracer\n");
+
+ irqsoff_busy = true;
+ return 0;
+}
+
+static void __irqsoff_tracer_reset(struct trace_array *tr)
+{
+ int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT;
+ int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE;
+ int pause_flag = save_flags & TRACE_ITER_PAUSE_ON_TRACE;
+
+ stop_irqsoff_tracer(tr, is_graph(tr));
+
+ set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag);
+ set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag);
+ set_tracer_flag(tr, TRACE_ITER_PAUSE_ON_TRACE, pause_flag);
+ ftrace_reset_array_ops(tr);
+
+ irqsoff_busy = false;
+}
+
+static void irqsoff_tracer_start(struct trace_array *tr)
+{
+ tracer_enabled = 1;
+}
+
+static void irqsoff_tracer_stop(struct trace_array *tr)
+{
+ tracer_enabled = 0;
+}
+
+#ifdef CONFIG_IRQSOFF_TRACER
+/*
+ * We are only interested in hardirq on/off events:
+ */
+void tracer_hardirqs_on(unsigned long a0, unsigned long a1)
+{
+ if (!preempt_trace(preempt_count()) && irq_trace())
+ stop_critical_timing(a0, a1);
+}
+NOKPROBE_SYMBOL(tracer_hardirqs_on);
+
+void tracer_hardirqs_off(unsigned long a0, unsigned long a1)
+{
+ if (!preempt_trace(preempt_count()) && irq_trace())
+ start_critical_timing(a0, a1);
+}
+NOKPROBE_SYMBOL(tracer_hardirqs_off);
+
+static int irqsoff_tracer_init(struct trace_array *tr)
+{
+ trace_type = TRACER_IRQS_OFF;
+
+ return __irqsoff_tracer_init(tr);
+}
+
+static void irqsoff_tracer_reset(struct trace_array *tr)
+{
+ __irqsoff_tracer_reset(tr);
+}
+
+static struct tracer irqsoff_tracer __read_mostly =
+{
+ .name = "irqsoff",
+ .init = irqsoff_tracer_init,
+ .reset = irqsoff_tracer_reset,
+ .start = irqsoff_tracer_start,
+ .stop = irqsoff_tracer_stop,
+ .print_max = true,
+ .print_header = irqsoff_print_header,
+ .print_line = irqsoff_print_line,
+ .flag_changed = irqsoff_flag_changed,
+#ifdef CONFIG_FTRACE_SELFTEST
+ .selftest = trace_selftest_startup_irqsoff,
+#endif
+ .open = irqsoff_trace_open,
+ .close = irqsoff_trace_close,
+ .allow_instances = true,
+ .use_max_tr = true,
+};
+#endif /* CONFIG_IRQSOFF_TRACER */
+
+#ifdef CONFIG_PREEMPT_TRACER
+void tracer_preempt_on(unsigned long a0, unsigned long a1)
+{
+ if (preempt_trace(preempt_count()) && !irq_trace())
+ stop_critical_timing(a0, a1);
+}
+
+void tracer_preempt_off(unsigned long a0, unsigned long a1)
+{
+ if (preempt_trace(preempt_count()) && !irq_trace())
+ start_critical_timing(a0, a1);
+}
+
+static int preemptoff_tracer_init(struct trace_array *tr)
+{
+ trace_type = TRACER_PREEMPT_OFF;
+
+ return __irqsoff_tracer_init(tr);
+}
+
+static void preemptoff_tracer_reset(struct trace_array *tr)
+{
+ __irqsoff_tracer_reset(tr);
+}
+
+static struct tracer preemptoff_tracer __read_mostly =
+{
+ .name = "preemptoff",
+ .init = preemptoff_tracer_init,
+ .reset = preemptoff_tracer_reset,
+ .start = irqsoff_tracer_start,
+ .stop = irqsoff_tracer_stop,
+ .print_max = true,
+ .print_header = irqsoff_print_header,
+ .print_line = irqsoff_print_line,
+ .flag_changed = irqsoff_flag_changed,
+#ifdef CONFIG_FTRACE_SELFTEST
+ .selftest = trace_selftest_startup_preemptoff,
+#endif
+ .open = irqsoff_trace_open,
+ .close = irqsoff_trace_close,
+ .allow_instances = true,
+ .use_max_tr = true,
+};
+#endif /* CONFIG_PREEMPT_TRACER */
+
+#if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
+
+static int preemptirqsoff_tracer_init(struct trace_array *tr)
+{
+ trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF;
+
+ return __irqsoff_tracer_init(tr);
+}
+
+static void preemptirqsoff_tracer_reset(struct trace_array *tr)
+{
+ __irqsoff_tracer_reset(tr);
+}
+
+static struct tracer preemptirqsoff_tracer __read_mostly =
+{
+ .name = "preemptirqsoff",
+ .init = preemptirqsoff_tracer_init,
+ .reset = preemptirqsoff_tracer_reset,
+ .start = irqsoff_tracer_start,
+ .stop = irqsoff_tracer_stop,
+ .print_max = true,
+ .print_header = irqsoff_print_header,
+ .print_line = irqsoff_print_line,
+ .flag_changed = irqsoff_flag_changed,
+#ifdef CONFIG_FTRACE_SELFTEST
+ .selftest = trace_selftest_startup_preemptirqsoff,
+#endif
+ .open = irqsoff_trace_open,
+ .close = irqsoff_trace_close,
+ .allow_instances = true,
+ .use_max_tr = true,
+};
+#endif
+
+__init static int init_irqsoff_tracer(void)
+{
+#ifdef CONFIG_IRQSOFF_TRACER
+ register_tracer(&irqsoff_tracer);
+#endif
+#ifdef CONFIG_PREEMPT_TRACER
+ register_tracer(&preemptoff_tracer);
+#endif
+#if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
+ register_tracer(&preemptirqsoff_tracer);
+#endif
+
+ return 0;
+}
+core_initcall(init_irqsoff_tracer);
+#endif /* IRQSOFF_TRACER || PREEMPTOFF_TRACER */