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![Sebastian Andrzej Siewior](/assets/img/avatar_default.png)
The state of the interrupts (irqflags) and the preemption counter are both passed down to tracing_generic_entry_update(). Only one bit of irqflags is actually required: The on/off state. The complete 32bit of the preemption counter isn't needed. Just whether of the upper bits (softirq, hardirq and NMI) are set and the preemption depth is needed. The irqflags and the preemption counter could be evaluated early and the information stored in an integer `trace_ctx'. tracing_generic_entry_update() would use the upper bits as the TRACE_FLAG_* and the lower 8bit as the disabled-preemption depth (considering that one must be substracted from the counter in one special cases). The actual preemption value is not used except for the tracing record. The `irqflags' variable is mostly used only for the tracing record. An exception here is for instance wakeup_tracer_call() or probe_wakeup_sched_switch() which explicilty disable interrupts and use that `irqflags' to save (and restore) the IRQ state and to record the state. Struct trace_event_buffer has also the `pc' and flags' members which can be replaced with `trace_ctx' since their actual value is not used outside of trace recording. This will reduce tracing_generic_entry_update() to simply assign values to struct trace_entry. The evaluation of the TRACE_FLAG_* bits is moved to _tracing_gen_ctx_flags() which replaces preempt_count() and local_save_flags() invocations. As an example, ftrace_syscall_enter() may invoke: - trace_buffer_lock_reserve() -> … -> tracing_generic_entry_update() - event_trigger_unlock_commit() -> ftrace_trace_stack() -> … -> tracing_generic_entry_update() -> ftrace_trace_userstack() -> … -> tracing_generic_entry_update() In this case the TRACE_FLAG_* bits were evaluated three times. By using the `trace_ctx' they are evaluated once and assigned three times. A build with all tracers enabled on x86-64 with and without the patch: text data bss dec hex filename 21970669 17084168 7639260 46694097 2c87ed1 vmlinux.old 21970293 17084168 7639260 46693721 2c87d59 vmlinux.new text shrank by 379 bytes, data remained constant. Link: https://lkml.kernel.org/r/20210125194511.3924915-2-bigeasy@linutronix.de Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
812 lines
18 KiB
C
812 lines
18 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* ring buffer based function tracer
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*
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* Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
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* Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
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*
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* Based on code from the latency_tracer, that is:
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*
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* Copyright (C) 2004-2006 Ingo Molnar
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* Copyright (C) 2004 Nadia Yvette Chambers
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*/
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#include <linux/ring_buffer.h>
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#include <linux/debugfs.h>
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#include <linux/uaccess.h>
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#include <linux/ftrace.h>
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#include <linux/slab.h>
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#include <linux/fs.h>
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#include "trace.h"
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static void tracing_start_function_trace(struct trace_array *tr);
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static void tracing_stop_function_trace(struct trace_array *tr);
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static void
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function_trace_call(unsigned long ip, unsigned long parent_ip,
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struct ftrace_ops *op, struct ftrace_regs *fregs);
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static void
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function_stack_trace_call(unsigned long ip, unsigned long parent_ip,
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struct ftrace_ops *op, struct ftrace_regs *fregs);
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static struct tracer_flags func_flags;
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/* Our option */
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enum {
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TRACE_FUNC_OPT_STACK = 0x1,
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};
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int ftrace_allocate_ftrace_ops(struct trace_array *tr)
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{
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struct ftrace_ops *ops;
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/* The top level array uses the "global_ops" */
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if (tr->flags & TRACE_ARRAY_FL_GLOBAL)
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return 0;
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ops = kzalloc(sizeof(*ops), GFP_KERNEL);
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if (!ops)
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return -ENOMEM;
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/* Currently only the non stack version is supported */
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ops->func = function_trace_call;
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ops->flags = FTRACE_OPS_FL_PID;
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tr->ops = ops;
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ops->private = tr;
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return 0;
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}
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void ftrace_free_ftrace_ops(struct trace_array *tr)
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{
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kfree(tr->ops);
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tr->ops = NULL;
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}
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int ftrace_create_function_files(struct trace_array *tr,
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struct dentry *parent)
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{
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/*
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* The top level array uses the "global_ops", and the files are
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* created on boot up.
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*/
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if (tr->flags & TRACE_ARRAY_FL_GLOBAL)
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return 0;
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if (!tr->ops)
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return -EINVAL;
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ftrace_create_filter_files(tr->ops, parent);
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return 0;
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}
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void ftrace_destroy_function_files(struct trace_array *tr)
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{
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ftrace_destroy_filter_files(tr->ops);
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ftrace_free_ftrace_ops(tr);
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}
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static int function_trace_init(struct trace_array *tr)
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{
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ftrace_func_t func;
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/*
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* Instance trace_arrays get their ops allocated
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* at instance creation. Unless it failed
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* the allocation.
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*/
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if (!tr->ops)
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return -ENOMEM;
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/* Currently only the global instance can do stack tracing */
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if (tr->flags & TRACE_ARRAY_FL_GLOBAL &&
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func_flags.val & TRACE_FUNC_OPT_STACK)
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func = function_stack_trace_call;
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else
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func = function_trace_call;
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ftrace_init_array_ops(tr, func);
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tr->array_buffer.cpu = raw_smp_processor_id();
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tracing_start_cmdline_record();
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tracing_start_function_trace(tr);
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return 0;
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}
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static void function_trace_reset(struct trace_array *tr)
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{
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tracing_stop_function_trace(tr);
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tracing_stop_cmdline_record();
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ftrace_reset_array_ops(tr);
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}
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static void function_trace_start(struct trace_array *tr)
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{
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tracing_reset_online_cpus(&tr->array_buffer);
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}
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static void
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function_trace_call(unsigned long ip, unsigned long parent_ip,
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struct ftrace_ops *op, struct ftrace_regs *fregs)
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{
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struct trace_array *tr = op->private;
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struct trace_array_cpu *data;
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unsigned int trace_ctx;
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int bit;
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int cpu;
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if (unlikely(!tr->function_enabled))
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return;
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bit = ftrace_test_recursion_trylock(ip, parent_ip);
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if (bit < 0)
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return;
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trace_ctx = tracing_gen_ctx();
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preempt_disable_notrace();
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cpu = smp_processor_id();
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data = per_cpu_ptr(tr->array_buffer.data, cpu);
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if (!atomic_read(&data->disabled))
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trace_function(tr, ip, parent_ip, trace_ctx);
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ftrace_test_recursion_unlock(bit);
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preempt_enable_notrace();
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}
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#ifdef CONFIG_UNWINDER_ORC
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/*
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* Skip 2:
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*
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* function_stack_trace_call()
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* ftrace_call()
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*/
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#define STACK_SKIP 2
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#else
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/*
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* Skip 3:
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* __trace_stack()
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* function_stack_trace_call()
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* ftrace_call()
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*/
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#define STACK_SKIP 3
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#endif
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static void
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function_stack_trace_call(unsigned long ip, unsigned long parent_ip,
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struct ftrace_ops *op, struct ftrace_regs *fregs)
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{
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struct trace_array *tr = op->private;
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struct trace_array_cpu *data;
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unsigned long flags;
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long disabled;
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int cpu;
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unsigned int trace_ctx;
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if (unlikely(!tr->function_enabled))
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return;
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/*
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* Need to use raw, since this must be called before the
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* recursive protection is performed.
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*/
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local_irq_save(flags);
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cpu = raw_smp_processor_id();
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data = per_cpu_ptr(tr->array_buffer.data, cpu);
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disabled = atomic_inc_return(&data->disabled);
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if (likely(disabled == 1)) {
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trace_ctx = tracing_gen_ctx_flags(flags);
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trace_function(tr, ip, parent_ip, trace_ctx);
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__trace_stack(tr, trace_ctx, STACK_SKIP);
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}
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atomic_dec(&data->disabled);
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local_irq_restore(flags);
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}
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static struct tracer_opt func_opts[] = {
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#ifdef CONFIG_STACKTRACE
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{ TRACER_OPT(func_stack_trace, TRACE_FUNC_OPT_STACK) },
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#endif
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{ } /* Always set a last empty entry */
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};
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static struct tracer_flags func_flags = {
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.val = 0, /* By default: all flags disabled */
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.opts = func_opts
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};
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static void tracing_start_function_trace(struct trace_array *tr)
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{
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tr->function_enabled = 0;
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register_ftrace_function(tr->ops);
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tr->function_enabled = 1;
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}
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static void tracing_stop_function_trace(struct trace_array *tr)
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{
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tr->function_enabled = 0;
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unregister_ftrace_function(tr->ops);
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}
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static struct tracer function_trace;
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static int
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func_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
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{
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switch (bit) {
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case TRACE_FUNC_OPT_STACK:
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/* do nothing if already set */
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if (!!set == !!(func_flags.val & TRACE_FUNC_OPT_STACK))
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break;
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/* We can change this flag when not running. */
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if (tr->current_trace != &function_trace)
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break;
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unregister_ftrace_function(tr->ops);
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if (set) {
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tr->ops->func = function_stack_trace_call;
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register_ftrace_function(tr->ops);
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} else {
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tr->ops->func = function_trace_call;
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register_ftrace_function(tr->ops);
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}
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break;
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default:
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return -EINVAL;
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}
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return 0;
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}
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static struct tracer function_trace __tracer_data =
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{
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.name = "function",
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.init = function_trace_init,
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.reset = function_trace_reset,
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.start = function_trace_start,
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.flags = &func_flags,
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.set_flag = func_set_flag,
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.allow_instances = true,
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#ifdef CONFIG_FTRACE_SELFTEST
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.selftest = trace_selftest_startup_function,
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#endif
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};
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#ifdef CONFIG_DYNAMIC_FTRACE
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static void update_traceon_count(struct ftrace_probe_ops *ops,
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unsigned long ip,
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struct trace_array *tr, bool on,
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void *data)
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{
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struct ftrace_func_mapper *mapper = data;
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long *count;
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long old_count;
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/*
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* Tracing gets disabled (or enabled) once per count.
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* This function can be called at the same time on multiple CPUs.
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* It is fine if both disable (or enable) tracing, as disabling
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* (or enabling) the second time doesn't do anything as the
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* state of the tracer is already disabled (or enabled).
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* What needs to be synchronized in this case is that the count
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* only gets decremented once, even if the tracer is disabled
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* (or enabled) twice, as the second one is really a nop.
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*
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* The memory barriers guarantee that we only decrement the
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* counter once. First the count is read to a local variable
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* and a read barrier is used to make sure that it is loaded
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* before checking if the tracer is in the state we want.
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* If the tracer is not in the state we want, then the count
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* is guaranteed to be the old count.
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*
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* Next the tracer is set to the state we want (disabled or enabled)
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* then a write memory barrier is used to make sure that
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* the new state is visible before changing the counter by
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* one minus the old counter. This guarantees that another CPU
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* executing this code will see the new state before seeing
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* the new counter value, and would not do anything if the new
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* counter is seen.
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*
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* Note, there is no synchronization between this and a user
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* setting the tracing_on file. But we currently don't care
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* about that.
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*/
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count = (long *)ftrace_func_mapper_find_ip(mapper, ip);
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old_count = *count;
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if (old_count <= 0)
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return;
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/* Make sure we see count before checking tracing state */
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smp_rmb();
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if (on == !!tracer_tracing_is_on(tr))
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return;
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if (on)
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tracer_tracing_on(tr);
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else
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tracer_tracing_off(tr);
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/* Make sure tracing state is visible before updating count */
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smp_wmb();
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*count = old_count - 1;
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}
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static void
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ftrace_traceon_count(unsigned long ip, unsigned long parent_ip,
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struct trace_array *tr, struct ftrace_probe_ops *ops,
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void *data)
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{
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update_traceon_count(ops, ip, tr, 1, data);
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}
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static void
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ftrace_traceoff_count(unsigned long ip, unsigned long parent_ip,
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struct trace_array *tr, struct ftrace_probe_ops *ops,
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void *data)
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{
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update_traceon_count(ops, ip, tr, 0, data);
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}
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static void
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ftrace_traceon(unsigned long ip, unsigned long parent_ip,
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struct trace_array *tr, struct ftrace_probe_ops *ops,
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void *data)
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{
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if (tracer_tracing_is_on(tr))
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return;
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tracer_tracing_on(tr);
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}
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static void
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ftrace_traceoff(unsigned long ip, unsigned long parent_ip,
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struct trace_array *tr, struct ftrace_probe_ops *ops,
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void *data)
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{
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if (!tracer_tracing_is_on(tr))
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return;
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tracer_tracing_off(tr);
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}
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#ifdef CONFIG_UNWINDER_ORC
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/*
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* Skip 3:
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*
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* function_trace_probe_call()
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* ftrace_ops_assist_func()
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* ftrace_call()
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*/
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#define FTRACE_STACK_SKIP 3
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#else
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/*
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* Skip 5:
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*
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* __trace_stack()
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* ftrace_stacktrace()
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* function_trace_probe_call()
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* ftrace_ops_assist_func()
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* ftrace_call()
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*/
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#define FTRACE_STACK_SKIP 5
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#endif
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static __always_inline void trace_stack(struct trace_array *tr)
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{
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unsigned int trace_ctx;
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trace_ctx = tracing_gen_ctx();
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__trace_stack(tr, trace_ctx, FTRACE_STACK_SKIP);
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}
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static void
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ftrace_stacktrace(unsigned long ip, unsigned long parent_ip,
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struct trace_array *tr, struct ftrace_probe_ops *ops,
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void *data)
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{
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trace_stack(tr);
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}
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static void
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ftrace_stacktrace_count(unsigned long ip, unsigned long parent_ip,
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struct trace_array *tr, struct ftrace_probe_ops *ops,
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void *data)
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{
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struct ftrace_func_mapper *mapper = data;
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long *count;
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long old_count;
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long new_count;
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if (!tracing_is_on())
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return;
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/* unlimited? */
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if (!mapper) {
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trace_stack(tr);
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return;
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}
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count = (long *)ftrace_func_mapper_find_ip(mapper, ip);
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/*
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* Stack traces should only execute the number of times the
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* user specified in the counter.
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*/
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do {
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old_count = *count;
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if (!old_count)
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return;
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new_count = old_count - 1;
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new_count = cmpxchg(count, old_count, new_count);
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if (new_count == old_count)
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trace_stack(tr);
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if (!tracing_is_on())
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return;
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} while (new_count != old_count);
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}
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static int update_count(struct ftrace_probe_ops *ops, unsigned long ip,
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void *data)
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{
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struct ftrace_func_mapper *mapper = data;
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long *count = NULL;
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if (mapper)
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count = (long *)ftrace_func_mapper_find_ip(mapper, ip);
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if (count) {
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if (*count <= 0)
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return 0;
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(*count)--;
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}
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return 1;
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}
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static void
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ftrace_dump_probe(unsigned long ip, unsigned long parent_ip,
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struct trace_array *tr, struct ftrace_probe_ops *ops,
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void *data)
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{
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if (update_count(ops, ip, data))
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ftrace_dump(DUMP_ALL);
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}
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/* Only dump the current CPU buffer. */
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static void
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ftrace_cpudump_probe(unsigned long ip, unsigned long parent_ip,
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struct trace_array *tr, struct ftrace_probe_ops *ops,
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void *data)
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{
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if (update_count(ops, ip, data))
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ftrace_dump(DUMP_ORIG);
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}
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static int
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ftrace_probe_print(const char *name, struct seq_file *m,
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unsigned long ip, struct ftrace_probe_ops *ops,
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void *data)
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{
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struct ftrace_func_mapper *mapper = data;
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long *count = NULL;
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seq_printf(m, "%ps:%s", (void *)ip, name);
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if (mapper)
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count = (long *)ftrace_func_mapper_find_ip(mapper, ip);
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if (count)
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seq_printf(m, ":count=%ld\n", *count);
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else
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seq_puts(m, ":unlimited\n");
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return 0;
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}
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static int
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ftrace_traceon_print(struct seq_file *m, unsigned long ip,
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struct ftrace_probe_ops *ops,
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void *data)
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|
{
|
|
return ftrace_probe_print("traceon", m, ip, ops, data);
|
|
}
|
|
|
|
static int
|
|
ftrace_traceoff_print(struct seq_file *m, unsigned long ip,
|
|
struct ftrace_probe_ops *ops, void *data)
|
|
{
|
|
return ftrace_probe_print("traceoff", m, ip, ops, data);
|
|
}
|
|
|
|
static int
|
|
ftrace_stacktrace_print(struct seq_file *m, unsigned long ip,
|
|
struct ftrace_probe_ops *ops, void *data)
|
|
{
|
|
return ftrace_probe_print("stacktrace", m, ip, ops, data);
|
|
}
|
|
|
|
static int
|
|
ftrace_dump_print(struct seq_file *m, unsigned long ip,
|
|
struct ftrace_probe_ops *ops, void *data)
|
|
{
|
|
return ftrace_probe_print("dump", m, ip, ops, data);
|
|
}
|
|
|
|
static int
|
|
ftrace_cpudump_print(struct seq_file *m, unsigned long ip,
|
|
struct ftrace_probe_ops *ops, void *data)
|
|
{
|
|
return ftrace_probe_print("cpudump", m, ip, ops, data);
|
|
}
|
|
|
|
|
|
static int
|
|
ftrace_count_init(struct ftrace_probe_ops *ops, struct trace_array *tr,
|
|
unsigned long ip, void *init_data, void **data)
|
|
{
|
|
struct ftrace_func_mapper *mapper = *data;
|
|
|
|
if (!mapper) {
|
|
mapper = allocate_ftrace_func_mapper();
|
|
if (!mapper)
|
|
return -ENOMEM;
|
|
*data = mapper;
|
|
}
|
|
|
|
return ftrace_func_mapper_add_ip(mapper, ip, init_data);
|
|
}
|
|
|
|
static void
|
|
ftrace_count_free(struct ftrace_probe_ops *ops, struct trace_array *tr,
|
|
unsigned long ip, void *data)
|
|
{
|
|
struct ftrace_func_mapper *mapper = data;
|
|
|
|
if (!ip) {
|
|
free_ftrace_func_mapper(mapper, NULL);
|
|
return;
|
|
}
|
|
|
|
ftrace_func_mapper_remove_ip(mapper, ip);
|
|
}
|
|
|
|
static struct ftrace_probe_ops traceon_count_probe_ops = {
|
|
.func = ftrace_traceon_count,
|
|
.print = ftrace_traceon_print,
|
|
.init = ftrace_count_init,
|
|
.free = ftrace_count_free,
|
|
};
|
|
|
|
static struct ftrace_probe_ops traceoff_count_probe_ops = {
|
|
.func = ftrace_traceoff_count,
|
|
.print = ftrace_traceoff_print,
|
|
.init = ftrace_count_init,
|
|
.free = ftrace_count_free,
|
|
};
|
|
|
|
static struct ftrace_probe_ops stacktrace_count_probe_ops = {
|
|
.func = ftrace_stacktrace_count,
|
|
.print = ftrace_stacktrace_print,
|
|
.init = ftrace_count_init,
|
|
.free = ftrace_count_free,
|
|
};
|
|
|
|
static struct ftrace_probe_ops dump_probe_ops = {
|
|
.func = ftrace_dump_probe,
|
|
.print = ftrace_dump_print,
|
|
.init = ftrace_count_init,
|
|
.free = ftrace_count_free,
|
|
};
|
|
|
|
static struct ftrace_probe_ops cpudump_probe_ops = {
|
|
.func = ftrace_cpudump_probe,
|
|
.print = ftrace_cpudump_print,
|
|
};
|
|
|
|
static struct ftrace_probe_ops traceon_probe_ops = {
|
|
.func = ftrace_traceon,
|
|
.print = ftrace_traceon_print,
|
|
};
|
|
|
|
static struct ftrace_probe_ops traceoff_probe_ops = {
|
|
.func = ftrace_traceoff,
|
|
.print = ftrace_traceoff_print,
|
|
};
|
|
|
|
static struct ftrace_probe_ops stacktrace_probe_ops = {
|
|
.func = ftrace_stacktrace,
|
|
.print = ftrace_stacktrace_print,
|
|
};
|
|
|
|
static int
|
|
ftrace_trace_probe_callback(struct trace_array *tr,
|
|
struct ftrace_probe_ops *ops,
|
|
struct ftrace_hash *hash, char *glob,
|
|
char *cmd, char *param, int enable)
|
|
{
|
|
void *count = (void *)-1;
|
|
char *number;
|
|
int ret;
|
|
|
|
/* hash funcs only work with set_ftrace_filter */
|
|
if (!enable)
|
|
return -EINVAL;
|
|
|
|
if (glob[0] == '!')
|
|
return unregister_ftrace_function_probe_func(glob+1, tr, ops);
|
|
|
|
if (!param)
|
|
goto out_reg;
|
|
|
|
number = strsep(¶m, ":");
|
|
|
|
if (!strlen(number))
|
|
goto out_reg;
|
|
|
|
/*
|
|
* We use the callback data field (which is a pointer)
|
|
* as our counter.
|
|
*/
|
|
ret = kstrtoul(number, 0, (unsigned long *)&count);
|
|
if (ret)
|
|
return ret;
|
|
|
|
out_reg:
|
|
ret = register_ftrace_function_probe(glob, tr, ops, count);
|
|
|
|
return ret < 0 ? ret : 0;
|
|
}
|
|
|
|
static int
|
|
ftrace_trace_onoff_callback(struct trace_array *tr, struct ftrace_hash *hash,
|
|
char *glob, char *cmd, char *param, int enable)
|
|
{
|
|
struct ftrace_probe_ops *ops;
|
|
|
|
if (!tr)
|
|
return -ENODEV;
|
|
|
|
/* we register both traceon and traceoff to this callback */
|
|
if (strcmp(cmd, "traceon") == 0)
|
|
ops = param ? &traceon_count_probe_ops : &traceon_probe_ops;
|
|
else
|
|
ops = param ? &traceoff_count_probe_ops : &traceoff_probe_ops;
|
|
|
|
return ftrace_trace_probe_callback(tr, ops, hash, glob, cmd,
|
|
param, enable);
|
|
}
|
|
|
|
static int
|
|
ftrace_stacktrace_callback(struct trace_array *tr, struct ftrace_hash *hash,
|
|
char *glob, char *cmd, char *param, int enable)
|
|
{
|
|
struct ftrace_probe_ops *ops;
|
|
|
|
if (!tr)
|
|
return -ENODEV;
|
|
|
|
ops = param ? &stacktrace_count_probe_ops : &stacktrace_probe_ops;
|
|
|
|
return ftrace_trace_probe_callback(tr, ops, hash, glob, cmd,
|
|
param, enable);
|
|
}
|
|
|
|
static int
|
|
ftrace_dump_callback(struct trace_array *tr, struct ftrace_hash *hash,
|
|
char *glob, char *cmd, char *param, int enable)
|
|
{
|
|
struct ftrace_probe_ops *ops;
|
|
|
|
if (!tr)
|
|
return -ENODEV;
|
|
|
|
ops = &dump_probe_ops;
|
|
|
|
/* Only dump once. */
|
|
return ftrace_trace_probe_callback(tr, ops, hash, glob, cmd,
|
|
"1", enable);
|
|
}
|
|
|
|
static int
|
|
ftrace_cpudump_callback(struct trace_array *tr, struct ftrace_hash *hash,
|
|
char *glob, char *cmd, char *param, int enable)
|
|
{
|
|
struct ftrace_probe_ops *ops;
|
|
|
|
if (!tr)
|
|
return -ENODEV;
|
|
|
|
ops = &cpudump_probe_ops;
|
|
|
|
/* Only dump once. */
|
|
return ftrace_trace_probe_callback(tr, ops, hash, glob, cmd,
|
|
"1", enable);
|
|
}
|
|
|
|
static struct ftrace_func_command ftrace_traceon_cmd = {
|
|
.name = "traceon",
|
|
.func = ftrace_trace_onoff_callback,
|
|
};
|
|
|
|
static struct ftrace_func_command ftrace_traceoff_cmd = {
|
|
.name = "traceoff",
|
|
.func = ftrace_trace_onoff_callback,
|
|
};
|
|
|
|
static struct ftrace_func_command ftrace_stacktrace_cmd = {
|
|
.name = "stacktrace",
|
|
.func = ftrace_stacktrace_callback,
|
|
};
|
|
|
|
static struct ftrace_func_command ftrace_dump_cmd = {
|
|
.name = "dump",
|
|
.func = ftrace_dump_callback,
|
|
};
|
|
|
|
static struct ftrace_func_command ftrace_cpudump_cmd = {
|
|
.name = "cpudump",
|
|
.func = ftrace_cpudump_callback,
|
|
};
|
|
|
|
static int __init init_func_cmd_traceon(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = register_ftrace_command(&ftrace_traceoff_cmd);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = register_ftrace_command(&ftrace_traceon_cmd);
|
|
if (ret)
|
|
goto out_free_traceoff;
|
|
|
|
ret = register_ftrace_command(&ftrace_stacktrace_cmd);
|
|
if (ret)
|
|
goto out_free_traceon;
|
|
|
|
ret = register_ftrace_command(&ftrace_dump_cmd);
|
|
if (ret)
|
|
goto out_free_stacktrace;
|
|
|
|
ret = register_ftrace_command(&ftrace_cpudump_cmd);
|
|
if (ret)
|
|
goto out_free_dump;
|
|
|
|
return 0;
|
|
|
|
out_free_dump:
|
|
unregister_ftrace_command(&ftrace_dump_cmd);
|
|
out_free_stacktrace:
|
|
unregister_ftrace_command(&ftrace_stacktrace_cmd);
|
|
out_free_traceon:
|
|
unregister_ftrace_command(&ftrace_traceon_cmd);
|
|
out_free_traceoff:
|
|
unregister_ftrace_command(&ftrace_traceoff_cmd);
|
|
|
|
return ret;
|
|
}
|
|
#else
|
|
static inline int init_func_cmd_traceon(void)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_DYNAMIC_FTRACE */
|
|
|
|
__init int init_function_trace(void)
|
|
{
|
|
init_func_cmd_traceon();
|
|
return register_tracer(&function_trace);
|
|
}
|