// SPDX-License-Identifier: GPL-2.0 /* * trace irqs off critical timings * * Copyright (C) 2007-2008 Steven Rostedt <[email protected]> * Copyright (C) 2008 Ingo Molnar <[email protected]> * * 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 { … }; 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) { … } #else #define preempt_trace … #endif #ifdef CONFIG_IRQSOFF_TRACER static inline int irq_trace(void) { … } #else #define irq_trace … #endif #ifdef CONFIG_FUNCTION_GRAPH_TRACER static int irqsoff_display_graph(struct trace_array *tr, int set); #define is_graph(tr) … #else static inline int irqsoff_display_graph(struct trace_array *tr, int set) { return -EINVAL; } #define is_graph … #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) { … } /* * 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) { … } #endif /* CONFIG_FUNCTION_TRACER */ #ifdef CONFIG_FUNCTION_GRAPH_TRACER static int irqsoff_display_graph(struct trace_array *tr, int set) { … } static int irqsoff_graph_entry(struct ftrace_graph_ent *trace, struct fgraph_ops *gops) { … } static void irqsoff_graph_return(struct ftrace_graph_ret *trace, struct fgraph_ops *gops) { … } static struct fgraph_ops fgraph_ops = …; static void irqsoff_trace_open(struct trace_iterator *iter) { … } static void irqsoff_trace_close(struct trace_iterator *iter) { … } #define GRAPH_TRACER_FLAGS … static enum print_line_t irqsoff_print_line(struct trace_iterator *iter) { … } static void irqsoff_print_header(struct seq_file *s) { … } static void __trace_function(struct trace_array *tr, unsigned long ip, unsigned long parent_ip, unsigned int trace_ctx) { … } #else #define __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) { … } static void check_critical_timing(struct trace_array *tr, struct trace_array_cpu *data, unsigned long parent_ip, int cpu) { … } static nokprobe_inline void start_critical_timing(unsigned long ip, unsigned long parent_ip) { … } static nokprobe_inline void stop_critical_timing(unsigned long ip, unsigned long parent_ip) { … } /* start and stop critical timings used to for stoppage (in idle) */ void start_critical_timings(void) { … } EXPORT_SYMBOL_GPL(…); NOKPROBE_SYMBOL(start_critical_timings); void stop_critical_timings(void) { … } EXPORT_SYMBOL_GPL(…); 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) { … } static void unregister_irqsoff_function(struct trace_array *tr, int graph) { … } static int irqsoff_function_set(struct trace_array *tr, u32 mask, int set) { … } #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) { … } static int start_irqsoff_tracer(struct trace_array *tr, int graph) { … } static void stop_irqsoff_tracer(struct trace_array *tr, int graph) { … } static bool irqsoff_busy; static int __irqsoff_tracer_init(struct trace_array *tr) { … } static void __irqsoff_tracer_reset(struct trace_array *tr) { … } static void irqsoff_tracer_start(struct trace_array *tr) { … } static void irqsoff_tracer_stop(struct trace_array *tr) { … } #ifdef CONFIG_IRQSOFF_TRACER /* * We are only interested in hardirq on/off events: */ void tracer_hardirqs_on(unsigned long a0, unsigned long a1) { … } NOKPROBE_SYMBOL(tracer_hardirqs_on); void tracer_hardirqs_off(unsigned long a0, unsigned long a1) { … } NOKPROBE_SYMBOL(tracer_hardirqs_off); static int irqsoff_tracer_init(struct trace_array *tr) { … } static void irqsoff_tracer_reset(struct trace_array *tr) { … } static struct tracer irqsoff_tracer __read_mostly = …; #endif /* CONFIG_IRQSOFF_TRACER */ #ifdef CONFIG_PREEMPT_TRACER void tracer_preempt_on(unsigned long a0, unsigned long a1) { … } void tracer_preempt_off(unsigned long a0, unsigned long a1) { … } static int preemptoff_tracer_init(struct trace_array *tr) { … } static void preemptoff_tracer_reset(struct trace_array *tr) { … } static struct tracer preemptoff_tracer __read_mostly = …; #endif /* CONFIG_PREEMPT_TRACER */ #if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER) static int preemptirqsoff_tracer_init(struct trace_array *tr) { … } static void preemptirqsoff_tracer_reset(struct trace_array *tr) { … } static struct tracer preemptirqsoff_tracer __read_mostly = …; #endif __init static int init_irqsoff_tracer(void) { … } core_initcall(init_irqsoff_tracer); #endif /* IRQSOFF_TRACER || PREEMPTOFF_TRACER */
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