* Copyright (C) 2004-2006 Ingo Molnar
* Copyright (C) 2004 William Lee Irwin III
*/
+#include <linux/ring_buffer.h>
#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include <linux/ftrace.h>
#include "trace.h"
-static void start_function_trace(struct trace_array *tr)
+/* function tracing enabled */
+static int ftrace_function_enabled;
+
+static struct trace_array *func_trace;
+
+static void tracing_start_function_trace(void);
+static void tracing_stop_function_trace(void);
+
+static int function_trace_init(struct trace_array *tr)
{
+ func_trace = tr;
tr->cpu = get_cpu();
- tracing_reset_online_cpus(tr);
put_cpu();
tracing_start_cmdline_record();
tracing_start_function_trace();
+ return 0;
}
-static void stop_function_trace(struct trace_array *tr)
+static void function_trace_reset(struct trace_array *tr)
{
tracing_stop_function_trace();
tracing_stop_cmdline_record();
}
-static int function_trace_init(struct trace_array *tr)
+static void function_trace_start(struct trace_array *tr)
{
- start_function_trace(tr);
- return 0;
+ tracing_reset_online_cpus(tr);
}
-static void function_trace_reset(struct trace_array *tr)
+static void
+function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip)
+{
+ struct trace_array *tr = func_trace;
+ struct trace_array_cpu *data;
+ unsigned long flags;
+ long disabled;
+ int cpu, resched;
+ int pc;
+
+ if (unlikely(!ftrace_function_enabled))
+ return;
+
+ pc = preempt_count();
+ resched = ftrace_preempt_disable();
+ local_save_flags(flags);
+ cpu = raw_smp_processor_id();
+ data = tr->data[cpu];
+ disabled = atomic_inc_return(&data->disabled);
+
+ if (likely(disabled == 1))
+ trace_function(tr, ip, parent_ip, flags, pc);
+
+ atomic_dec(&data->disabled);
+ ftrace_preempt_enable(resched);
+}
+
+static void
+function_trace_call(unsigned long ip, unsigned long parent_ip)
{
- stop_function_trace(tr);
+ struct trace_array *tr = func_trace;
+ struct trace_array_cpu *data;
+ unsigned long flags;
+ long disabled;
+ int cpu;
+ int pc;
+
+ if (unlikely(!ftrace_function_enabled))
+ return;
+
+ /*
+ * Need to use raw, since this must be called before the
+ * recursive protection is performed.
+ */
+ local_irq_save(flags);
+ cpu = raw_smp_processor_id();
+ data = tr->data[cpu];
+ disabled = atomic_inc_return(&data->disabled);
+
+ if (likely(disabled == 1)) {
+ pc = preempt_count();
+ trace_function(tr, ip, parent_ip, flags, pc);
+ }
+
+ atomic_dec(&data->disabled);
+ local_irq_restore(flags);
}
-static void function_trace_start(struct trace_array *tr)
+static void
+function_stack_trace_call(unsigned long ip, unsigned long parent_ip)
{
- tracing_reset_online_cpus(tr);
+ struct trace_array *tr = func_trace;
+ struct trace_array_cpu *data;
+ unsigned long flags;
+ long disabled;
+ int cpu;
+ int pc;
+
+ if (unlikely(!ftrace_function_enabled))
+ return;
+
+ /*
+ * Need to use raw, since this must be called before the
+ * recursive protection is performed.
+ */
+ local_irq_save(flags);
+ cpu = raw_smp_processor_id();
+ data = tr->data[cpu];
+ disabled = atomic_inc_return(&data->disabled);
+
+ if (likely(disabled == 1)) {
+ pc = preempt_count();
+ trace_function(tr, ip, parent_ip, flags, pc);
+ /*
+ * skip over 5 funcs:
+ * __ftrace_trace_stack,
+ * __trace_stack,
+ * function_stack_trace_call
+ * ftrace_list_func
+ * ftrace_call
+ */
+ __trace_stack(tr, flags, 5, pc);
+ }
+
+ atomic_dec(&data->disabled);
+ local_irq_restore(flags);
+}
+
+
+static struct ftrace_ops trace_ops __read_mostly =
+{
+ .func = function_trace_call,
+};
+
+static struct ftrace_ops trace_stack_ops __read_mostly =
+{
+ .func = function_stack_trace_call,
+};
+
+/* Our two options */
+enum {
+ TRACE_FUNC_OPT_STACK = 0x1,
+};
+
+static struct tracer_opt func_opts[] = {
+#ifdef CONFIG_STACKTRACE
+ { TRACER_OPT(func_stack_trace, TRACE_FUNC_OPT_STACK) },
+#endif
+ { } /* Always set a last empty entry */
+};
+
+static struct tracer_flags func_flags = {
+ .val = 0, /* By default: all flags disabled */
+ .opts = func_opts
+};
+
+static void tracing_start_function_trace(void)
+{
+ ftrace_function_enabled = 0;
+
+ if (trace_flags & TRACE_ITER_PREEMPTONLY)
+ trace_ops.func = function_trace_call_preempt_only;
+ else
+ trace_ops.func = function_trace_call;
+
+ if (func_flags.val & TRACE_FUNC_OPT_STACK)
+ register_ftrace_function(&trace_stack_ops);
+ else
+ register_ftrace_function(&trace_ops);
+
+ ftrace_function_enabled = 1;
+}
+
+static void tracing_stop_function_trace(void)
+{
+ ftrace_function_enabled = 0;
+
+ if (func_flags.val & TRACE_FUNC_OPT_STACK)
+ unregister_ftrace_function(&trace_stack_ops);
+ else
+ unregister_ftrace_function(&trace_ops);
+}
+
+static int func_set_flag(u32 old_flags, u32 bit, int set)
+{
+ if (bit == TRACE_FUNC_OPT_STACK) {
+ /* do nothing if already set */
+ if (!!set == !!(func_flags.val & TRACE_FUNC_OPT_STACK))
+ return 0;
+
+ if (set) {
+ unregister_ftrace_function(&trace_ops);
+ register_ftrace_function(&trace_stack_ops);
+ } else {
+ unregister_ftrace_function(&trace_stack_ops);
+ register_ftrace_function(&trace_ops);
+ }
+
+ return 0;
+ }
+
+ return -EINVAL;
}
static struct tracer function_trace __read_mostly =
{
- .name = "function",
- .init = function_trace_init,
- .reset = function_trace_reset,
- .start = function_trace_start,
+ .name = "function",
+ .init = function_trace_init,
+ .reset = function_trace_reset,
+ .start = function_trace_start,
+ .wait_pipe = poll_wait_pipe,
+ .flags = &func_flags,
+ .set_flag = func_set_flag,
#ifdef CONFIG_FTRACE_SELFTEST
- .selftest = trace_selftest_startup_function,
+ .selftest = trace_selftest_startup_function,
#endif
};
+#ifdef CONFIG_DYNAMIC_FTRACE
+static void
+ftrace_traceon(unsigned long ip, unsigned long parent_ip, void **data)
+{
+ long *count = (long *)data;
+
+ if (tracing_is_on())
+ return;
+
+ if (!*count)
+ return;
+
+ if (*count != -1)
+ (*count)--;
+
+ tracing_on();
+}
+
+static void
+ftrace_traceoff(unsigned long ip, unsigned long parent_ip, void **data)
+{
+ long *count = (long *)data;
+
+ if (!tracing_is_on())
+ return;
+
+ if (!*count)
+ return;
+
+ if (*count != -1)
+ (*count)--;
+
+ tracing_off();
+}
+
+static int
+ftrace_trace_onoff_print(struct seq_file *m, unsigned long ip,
+ struct ftrace_probe_ops *ops, void *data);
+
+static struct ftrace_probe_ops traceon_probe_ops = {
+ .func = ftrace_traceon,
+ .print = ftrace_trace_onoff_print,
+};
+
+static struct ftrace_probe_ops traceoff_probe_ops = {
+ .func = ftrace_traceoff,
+ .print = ftrace_trace_onoff_print,
+};
+
+static int
+ftrace_trace_onoff_print(struct seq_file *m, unsigned long ip,
+ struct ftrace_probe_ops *ops, void *data)
+{
+ long count = (long)data;
+
+ seq_printf(m, "%ps:", (void *)ip);
+
+ if (ops == &traceon_probe_ops)
+ seq_printf(m, "traceon");
+ else
+ seq_printf(m, "traceoff");
+
+ if (count == -1)
+ seq_printf(m, ":unlimited\n");
+ else
+ seq_printf(m, ":count=%ld\n", count);
+
+ return 0;
+}
+
+static int
+ftrace_trace_onoff_unreg(char *glob, char *cmd, char *param)
+{
+ struct ftrace_probe_ops *ops;
+
+ /* we register both traceon and traceoff to this callback */
+ if (strcmp(cmd, "traceon") == 0)
+ ops = &traceon_probe_ops;
+ else
+ ops = &traceoff_probe_ops;
+
+ unregister_ftrace_function_probe_func(glob, ops);
+
+ return 0;
+}
+
+static int
+ftrace_trace_onoff_callback(char *glob, char *cmd, char *param, int enable)
+{
+ struct ftrace_probe_ops *ops;
+ void *count = (void *)-1;
+ char *number;
+ int ret;
+
+ /* hash funcs only work with set_ftrace_filter */
+ if (!enable)
+ return -EINVAL;
+
+ if (glob[0] == '!')
+ return ftrace_trace_onoff_unreg(glob+1, cmd, param);
+
+ /* we register both traceon and traceoff to this callback */
+ if (strcmp(cmd, "traceon") == 0)
+ ops = &traceon_probe_ops;
+ else
+ ops = &traceoff_probe_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 = strict_strtoul(number, 0, (unsigned long *)&count);
+ if (ret)
+ return ret;
+
+ out_reg:
+ ret = register_ftrace_function_probe(glob, ops, count);
+
+ return ret < 0 ? ret : 0;
+}
+
+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 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)
+ unregister_ftrace_command(&ftrace_traceoff_cmd);
+ return ret;
+}
+#else
+static inline int init_func_cmd_traceon(void)
+{
+ return 0;
+}
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
static __init int init_function_trace(void)
{
+ init_func_cmd_traceon();
return register_tracer(&function_trace);
}
-
device_initcall(init_function_trace);
+
Code Review / linux-2.6.git / blobdiff