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Commit e4106133 authored by Ingo Molnar's avatar Ingo Molnar
Browse files

Merge branch 'tracing/syscalls' into tracing/core

parents 7243f214 2fc1dfbe

kernel/trace/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -182,6 +182,7 @@ config FTRACE_SYSCALLS 
	bool "Trace syscalls"

	depends on HAVE_FTRACE_SYSCALLS

	select TRACING

	select KALLSYMS

	help

	  Basic tracer to catch the syscall entry and exit events.

kernel/trace/trace.c

+3 −2
Original line number Diff line number Diff line
@@ -2494,7 +2494,7 @@ static int tracing_set_tracer(const char *buf) 
	if (!ring_buffer_expanded) {

		ret = tracing_resize_ring_buffer(trace_buf_size);

		if (ret < 0)

			return ret;

			goto out;

		ret = 0;

	}
@@ -4125,7 +4125,8 @@ __init static int tracer_alloc_buffers(void) 
				       &trace_panic_notifier);



	register_die_notifier(&trace_die_notifier);

	ret = 0;



	return 0;



out_free_cpumask:

	free_cpumask_var(tracing_reader_cpumask);

kernel/trace/trace_selftest.c

+6 −10
Original line number Diff line number Diff line
@@ -414,7 +414,7 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array * 
	ret = tracer_init(trace, tr);

	if (ret) {

		warn_failed_init_tracer(trace, ret);

		goto out;

		goto out_no_start;

	}



	/* reset the max latency */
@@ -432,21 +432,16 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array * 
	tracing_stop();

	/* check both trace buffers */

	ret = trace_test_buffer(tr, NULL);

	if (ret) {

		tracing_start();

	if (ret)

		goto out;

	}



	ret = trace_test_buffer(&max_tr, &count);

	if (ret) {

		tracing_start();

	if (ret)

		goto out;

	}



	if (!ret && !count) {

		printk(KERN_CONT ".. no entries found ..");

		ret = -1;

		tracing_start();

		goto out;

	}
@@ -476,8 +471,9 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array * 
	}



out:

	trace->reset(tr);

	tracing_start();

out_no_start:

	trace->reset(tr);

	tracing_max_latency = save_max;



	return ret;

kernel/trace/trace_syscalls.c

+24 −17
Original line number Diff line number Diff line
@@ -5,9 +5,13 @@ 
#include "trace_output.h"

#include "trace.h"



static atomic_t refcount;

/* Keep a counter of the syscall tracing users */

static int refcount;



/* Our two options */

/* Prevent from races on thread flags toggling */

static DEFINE_MUTEX(syscall_trace_lock);



/* Option to display the parameters types */

enum {

	TRACE_SYSCALLS_OPT_TYPES = 0x1,

};
@@ -18,7 +22,7 @@ static struct tracer_opt syscalls_opts[] = { 
};



static struct tracer_flags syscalls_flags = {

	.val = 0, /* By default: no args types */

	.val = 0, /* By default: no parameters types */

	.opts = syscalls_opts

};
@@ -96,8 +100,11 @@ void start_ftrace_syscalls(void) 
	unsigned long flags;

	struct task_struct *g, *t;



	if (atomic_inc_return(&refcount) != 1)

		goto out;

	mutex_lock(&syscall_trace_lock);



	/* Don't enable the flag on the tasks twice */

	if (++refcount != 1)

		goto unlock;



	arch_init_ftrace_syscalls();

	read_lock_irqsave(&tasklist_lock, flags);
@@ -107,8 +114,9 @@ void start_ftrace_syscalls(void) 
	} while_each_thread(g, t);



	read_unlock_irqrestore(&tasklist_lock, flags);

out:

	atomic_dec(&refcount);



unlock:

	mutex_unlock(&syscall_trace_lock);

}



void stop_ftrace_syscalls(void)
@@ -116,8 +124,11 @@ void stop_ftrace_syscalls(void) 
	unsigned long flags;

	struct task_struct *g, *t;



	if (atomic_dec_return(&refcount))

		goto out;

	mutex_lock(&syscall_trace_lock);



	/* There are perhaps still some users */

	if (--refcount)

		goto unlock;



	read_lock_irqsave(&tasklist_lock, flags);
@@ -126,8 +137,9 @@ void stop_ftrace_syscalls(void) 
	} while_each_thread(g, t);



	read_unlock_irqrestore(&tasklist_lock, flags);

out:

	atomic_inc(&refcount);



unlock:

	mutex_unlock(&syscall_trace_lock);

}



void ftrace_syscall_enter(struct pt_regs *regs)
@@ -137,12 +149,9 @@ void ftrace_syscall_enter(struct pt_regs *regs) 
	struct ring_buffer_event *event;

	int size;

	int syscall_nr;

	int cpu;



	syscall_nr = syscall_get_nr(current, regs);



	cpu = raw_smp_processor_id();



	sys_data = syscall_nr_to_meta(syscall_nr);

	if (!sys_data)

		return;
@@ -168,12 +177,9 @@ void ftrace_syscall_exit(struct pt_regs *regs) 
	struct syscall_metadata *sys_data;

	struct ring_buffer_event *event;

	int syscall_nr;

	int cpu;



	syscall_nr = syscall_get_nr(current, regs);



	cpu = raw_smp_processor_id();



	sys_data = syscall_nr_to_meta(syscall_nr);

	if (!sys_data)

		return;
@@ -201,6 +207,7 @@ static int init_syscall_tracer(struct trace_array *tr) 
static void reset_syscall_tracer(struct trace_array *tr)

{

	stop_ftrace_syscalls();

	tracing_reset_online_cpus(tr);

}



static struct trace_event syscall_enter_event = {