Merge branch 'tracing/function-return-tracer' into tracing/fastboot
This commit is contained in:
@@ -23,6 +23,10 @@ CFLAGS_REMOVE_cgroup-debug.o = -pg
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CFLAGS_REMOVE_sched_clock.o = -pg
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CFLAGS_REMOVE_sched.o = -mno-spe -pg
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endif
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ifdef CONFIG_FUNCTION_RET_TRACER
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CFLAGS_REMOVE_extable.o = -pg # For __kernel_text_address()
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CFLAGS_REMOVE_module.o = -pg # For __module_text_address()
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endif
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obj-$(CONFIG_FREEZER) += freezer.o
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obj-$(CONFIG_PROFILING) += profile.o
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@@ -9,6 +9,9 @@ config NOP_TRACER
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config HAVE_FUNCTION_TRACER
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bool
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config HAVE_FUNCTION_RET_TRACER
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bool
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config HAVE_FUNCTION_TRACE_MCOUNT_TEST
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bool
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help
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@@ -54,6 +57,17 @@ config FUNCTION_TRACER
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(the bootup default), then the overhead of the instructions is very
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small and not measurable even in micro-benchmarks.
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config FUNCTION_RET_TRACER
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bool "Kernel Function return Tracer"
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depends on !DYNAMIC_FTRACE
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depends on HAVE_FUNCTION_RET_TRACER
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depends on FUNCTION_TRACER
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help
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Enable the kernel to trace a function at its return.
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It's first purpose is to trace the duration of functions.
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This is done by setting the current return address on the thread
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info structure of the current task.
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config IRQSOFF_TRACER
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bool "Interrupts-off Latency Tracer"
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default n
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@@ -24,5 +24,6 @@ obj-$(CONFIG_NOP_TRACER) += trace_nop.o
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obj-$(CONFIG_STACK_TRACER) += trace_stack.o
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obj-$(CONFIG_MMIOTRACE) += trace_mmiotrace.o
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obj-$(CONFIG_BOOT_TRACER) += trace_boot.o
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obj-$(CONFIG_FUNCTION_RET_TRACER) += trace_functions_return.o
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libftrace-y := ftrace.o
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@@ -1480,3 +1480,19 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
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return ret;
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}
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#ifdef CONFIG_FUNCTION_RET_TRACER
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trace_function_return_t ftrace_function_return =
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(trace_function_return_t)ftrace_stub;
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void register_ftrace_return(trace_function_return_t func)
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{
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ftrace_function_return = func;
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}
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void unregister_ftrace_return(void)
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{
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ftrace_function_return = (trace_function_return_t)ftrace_stub;
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}
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#endif
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@@ -244,13 +244,6 @@ unsigned long nsecs_to_usecs(unsigned long nsecs)
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return nsecs / 1000;
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}
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/*
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* TRACE_ITER_SYM_MASK masks the options in trace_flags that
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* control the output of kernel symbols.
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*/
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#define TRACE_ITER_SYM_MASK \
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(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
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/* These must match the bit postions in trace_iterator_flags */
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static const char *trace_options[] = {
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"print-parent",
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@@ -810,6 +803,35 @@ trace_function(struct trace_array *tr, struct trace_array_cpu *data,
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ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
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}
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#ifdef CONFIG_FUNCTION_RET_TRACER
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static void __trace_function_return(struct trace_array *tr,
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struct trace_array_cpu *data,
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struct ftrace_retfunc *trace,
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unsigned long flags,
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int pc)
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{
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struct ring_buffer_event *event;
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struct ftrace_ret_entry *entry;
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unsigned long irq_flags;
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if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
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return;
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event = ring_buffer_lock_reserve(global_trace.buffer, sizeof(*entry),
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&irq_flags);
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if (!event)
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return;
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entry = ring_buffer_event_data(event);
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tracing_generic_entry_update(&entry->ent, flags, pc);
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entry->ent.type = TRACE_FN_RET;
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entry->ip = trace->func;
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entry->parent_ip = trace->ret;
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entry->rettime = trace->rettime;
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entry->calltime = trace->calltime;
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ring_buffer_unlock_commit(global_trace.buffer, event, irq_flags);
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}
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#endif
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void
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ftrace(struct trace_array *tr, struct trace_array_cpu *data,
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unsigned long ip, unsigned long parent_ip, unsigned long flags,
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@@ -1038,6 +1060,29 @@ function_trace_call(unsigned long ip, unsigned long parent_ip)
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raw_local_irq_restore(flags);
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}
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#ifdef CONFIG_FUNCTION_RET_TRACER
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void trace_function_return(struct ftrace_retfunc *trace)
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{
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struct trace_array *tr = &global_trace;
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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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int pc;
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raw_local_irq_save(flags);
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cpu = raw_smp_processor_id();
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data = tr->data[cpu];
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disabled = atomic_inc_return(&data->disabled);
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if (likely(disabled == 1)) {
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pc = preempt_count();
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__trace_function_return(tr, data, trace, flags, pc);
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}
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atomic_dec(&data->disabled);
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raw_local_irq_restore(flags);
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}
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#endif /* CONFIG_FUNCTION_RET_TRACER */
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static struct ftrace_ops trace_ops __read_mostly =
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{
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.func = function_trace_call,
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@@ -1285,7 +1330,7 @@ seq_print_sym_offset(struct trace_seq *s, const char *fmt,
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# define IP_FMT "%016lx"
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#endif
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static int
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int
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seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
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{
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int ret;
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@@ -1738,6 +1783,10 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
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trace_seq_print_cont(s, iter);
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break;
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}
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case TRACE_FN_RET: {
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return print_return_function(iter);
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break;
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}
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}
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return TRACE_TYPE_HANDLED;
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}
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@@ -22,6 +22,7 @@ enum trace_type {
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TRACE_MMIO_RW,
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TRACE_MMIO_MAP,
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TRACE_BOOT,
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TRACE_FN_RET,
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__TRACE_LAST_TYPE
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};
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@@ -48,6 +49,15 @@ struct ftrace_entry {
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unsigned long ip;
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unsigned long parent_ip;
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};
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/* Function return entry */
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struct ftrace_ret_entry {
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struct trace_entry ent;
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unsigned long ip;
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unsigned long parent_ip;
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unsigned long long calltime;
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unsigned long long rettime;
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};
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extern struct tracer boot_tracer;
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/*
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@@ -218,6 +228,7 @@ extern void __ftrace_bad_type(void);
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IF_ASSIGN(var, ent, struct trace_mmiotrace_map, \
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TRACE_MMIO_MAP); \
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IF_ASSIGN(var, ent, struct trace_boot, TRACE_BOOT); \
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IF_ASSIGN(var, ent, struct ftrace_ret_entry, TRACE_FN_RET); \
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__ftrace_bad_type(); \
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} while (0)
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@@ -321,6 +332,8 @@ void trace_function(struct trace_array *tr,
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unsigned long ip,
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unsigned long parent_ip,
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unsigned long flags, int pc);
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void
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trace_function_return(struct ftrace_retfunc *trace);
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void tracing_start_cmdline_record(void);
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void tracing_stop_cmdline_record(void);
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@@ -393,6 +406,10 @@ extern void *head_page(struct trace_array_cpu *data);
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extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...);
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extern void trace_seq_print_cont(struct trace_seq *s,
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struct trace_iterator *iter);
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extern int
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seq_print_ip_sym(struct trace_seq *s, unsigned long ip,
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unsigned long sym_flags);
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extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
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size_t cnt);
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extern long ns2usecs(cycle_t nsec);
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@@ -400,6 +417,17 @@ extern int trace_vprintk(unsigned long ip, const char *fmt, va_list args);
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extern unsigned long trace_flags;
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/* Standard output formatting function used for function return traces */
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#ifdef CONFIG_FUNCTION_RET_TRACER
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extern enum print_line_t print_return_function(struct trace_iterator *iter);
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#else
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static inline enum print_line_t
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print_return_function(struct trace_iterator *iter)
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{
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return TRACE_TYPE_UNHANDLED;
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}
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#endif
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/*
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* trace_iterator_flags is an enumeration that defines bit
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* positions into trace_flags that controls the output.
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@@ -422,6 +450,13 @@ enum trace_iterator_flags {
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TRACE_ITER_PREEMPTONLY = 0x800,
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};
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/*
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* TRACE_ITER_SYM_MASK masks the options in trace_flags that
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* control the output of kernel symbols.
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*/
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#define TRACE_ITER_SYM_MASK \
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(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
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extern struct tracer nop_trace;
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/**
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82
kernel/trace/trace_functions_return.c
Normal file
82
kernel/trace/trace_functions_return.c
Normal file
@@ -0,0 +1,82 @@
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/*
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*
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* Function return tracer.
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* Copyright (c) 2008 Frederic Weisbecker <fweisbec@gmail.com>
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* Mostly borrowed from function tracer which
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* is Copyright (c) Steven Rostedt <srostedt@redhat.com>
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*
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*/
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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/fs.h>
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#include "trace.h"
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static void start_return_trace(struct trace_array *tr)
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{
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register_ftrace_return(&trace_function_return);
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}
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static void stop_return_trace(struct trace_array *tr)
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{
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unregister_ftrace_return();
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}
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static void return_trace_init(struct trace_array *tr)
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{
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int cpu;
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for_each_online_cpu(cpu)
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tracing_reset(tr, cpu);
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start_return_trace(tr);
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}
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static void return_trace_reset(struct trace_array *tr)
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{
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stop_return_trace(tr);
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}
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enum print_line_t
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print_return_function(struct trace_iterator *iter)
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{
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struct trace_seq *s = &iter->seq;
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struct trace_entry *entry = iter->ent;
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struct ftrace_ret_entry *field;
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int ret;
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if (entry->type == TRACE_FN_RET) {
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trace_assign_type(field, entry);
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ret = trace_seq_printf(s, "%pF -> ", (void *)field->parent_ip);
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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ret = seq_print_ip_sym(s, field->ip,
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trace_flags & TRACE_ITER_SYM_MASK);
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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ret = trace_seq_printf(s, " (%llu ns)\n",
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field->rettime - field->calltime);
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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else
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return TRACE_TYPE_HANDLED;
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}
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return TRACE_TYPE_UNHANDLED;
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}
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static struct tracer return_trace __read_mostly =
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{
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.name = "return",
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.init = return_trace_init,
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.reset = return_trace_reset,
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.print_line = print_return_function
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};
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static __init int init_return_trace(void)
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{
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return register_tracer(&return_trace);
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}
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device_initcall(init_return_trace);
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