linux/kernel/trace/trace_selftest.c

865 lines
18 KiB
C
Raw Normal View History

/* Include in trace.c */
#include <linux/stringify.h>
#include <linux/kthread.h>
#include <linux/delay.h>
static inline int trace_valid_entry(struct trace_entry *entry)
{
switch (entry->type) {
case TRACE_FN:
case TRACE_CTX:
case TRACE_WAKE:
case TRACE_STACK:
case TRACE_PRINT:
case TRACE_SPECIAL:
case TRACE_BRANCH:
case TRACE_GRAPH_ENT:
case TRACE_GRAPH_RET:
case TRACE_HW_BRANCHES:
case TRACE_KSYM:
return 1;
}
return 0;
}
static int trace_test_buffer_cpu(struct trace_array *tr, int cpu)
{
struct ring_buffer_event *event;
struct trace_entry *entry;
unsigned int loops = 0;
while ((event = ring_buffer_consume(tr->buffer, cpu, NULL))) {
entry = ring_buffer_event_data(event);
/*
* The ring buffer is a size of trace_buf_size, if
* we loop more than the size, there's something wrong
* with the ring buffer.
*/
if (loops++ > trace_buf_size) {
printk(KERN_CONT ".. bad ring buffer ");
goto failed;
}
if (!trace_valid_entry(entry)) {
printk(KERN_CONT ".. invalid entry %d ",
entry->type);
goto failed;
}
}
return 0;
failed:
/* disable tracing */
tracing_disabled = 1;
printk(KERN_CONT ".. corrupted trace buffer .. ");
return -1;
}
/*
* Test the trace buffer to see if all the elements
* are still sane.
*/
static int trace_test_buffer(struct trace_array *tr, unsigned long *count)
{
unsigned long flags, cnt = 0;
int cpu, ret = 0;
/* Don't allow flipping of max traces now */
local_irq_save(flags);
__raw_spin_lock(&ftrace_max_lock);
cnt = ring_buffer_entries(tr->buffer);
/*
* The trace_test_buffer_cpu runs a while loop to consume all data.
* If the calling tracer is broken, and is constantly filling
* the buffer, this will run forever, and hard lock the box.
* We disable the ring buffer while we do this test to prevent
* a hard lock up.
*/
tracing_off();
for_each_possible_cpu(cpu) {
ret = trace_test_buffer_cpu(tr, cpu);
if (ret)
break;
}
tracing_on();
__raw_spin_unlock(&ftrace_max_lock);
local_irq_restore(flags);
if (count)
*count = cnt;
return ret;
}
static inline void warn_failed_init_tracer(struct tracer *trace, int init_ret)
{
printk(KERN_WARNING "Failed to init %s tracer, init returned %d\n",
trace->name, init_ret);
}
#ifdef CONFIG_FUNCTION_TRACER
#ifdef CONFIG_DYNAMIC_FTRACE
/* Test dynamic code modification and ftrace filters */
int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
struct trace_array *tr,
int (*func)(void))
{
int save_ftrace_enabled = ftrace_enabled;
int save_tracer_enabled = tracer_enabled;
unsigned long count;
char *func_name;
int ret;
/* The ftrace test PASSED */
printk(KERN_CONT "PASSED\n");
pr_info("Testing dynamic ftrace: ");
/* enable tracing, and record the filter function */
ftrace_enabled = 1;
tracer_enabled = 1;
/* passed in by parameter to fool gcc from optimizing */
func();
/*
* Some archs *cough*PowerPC*cough* add characters to the
* start of the function names. We simply put a '*' to
* accommodate them.
*/
func_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
/* filter only on our function */
ftrace_set_filter(func_name, strlen(func_name), 1);
/* enable tracing */
ret = tracer_init(trace, tr);
if (ret) {
warn_failed_init_tracer(trace, ret);
goto out;
}
/* Sleep for a 1/10 of a second */
msleep(100);
/* we should have nothing in the buffer */
ret = trace_test_buffer(tr, &count);
if (ret)
goto out;
if (count) {
ret = -1;
printk(KERN_CONT ".. filter did not filter .. ");
goto out;
}
/* call our function again */
func();
/* sleep again */
msleep(100);
/* stop the tracing. */
tracing_stop();
ftrace_enabled = 0;
/* check the trace buffer */
ret = trace_test_buffer(tr, &count);
trace->reset(tr);
tracing_start();
/* we should only have one item */
if (!ret && count != 1) {
printk(KERN_CONT ".. filter failed count=%ld ..", count);
ret = -1;
goto out;
}
out:
ftrace_enabled = save_ftrace_enabled;
tracer_enabled = save_tracer_enabled;
/* Enable tracing on all functions again */
ftrace_set_filter(NULL, 0, 1);
return ret;
}
#else
# define trace_selftest_startup_dynamic_tracing(trace, tr, func) ({ 0; })
#endif /* CONFIG_DYNAMIC_FTRACE */
/*
* Simple verification test of ftrace function tracer.
* Enable ftrace, sleep 1/10 second, and then read the trace
* buffer to see if all is in order.
*/
int
trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
{
int save_ftrace_enabled = ftrace_enabled;
int save_tracer_enabled = tracer_enabled;
unsigned long count;
int ret;
/* make sure msleep has been recorded */
msleep(1);
/* start the tracing */
ftrace_enabled = 1;
tracer_enabled = 1;
ret = tracer_init(trace, tr);
if (ret) {
warn_failed_init_tracer(trace, ret);
goto out;
}
/* Sleep for a 1/10 of a second */
msleep(100);
/* stop the tracing. */
tracing_stop();
ftrace_enabled = 0;
/* check the trace buffer */
ret = trace_test_buffer(tr, &count);
trace->reset(tr);
tracing_start();
if (!ret && !count) {
printk(KERN_CONT ".. no entries found ..");
ret = -1;
goto out;
}
ret = trace_selftest_startup_dynamic_tracing(trace, tr,
DYN_FTRACE_TEST_NAME);
out:
ftrace_enabled = save_ftrace_enabled;
tracer_enabled = save_tracer_enabled;
/* kill ftrace totally if we failed */
if (ret)
ftrace_kill();
return ret;
}
#endif /* CONFIG_FUNCTION_TRACER */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
/* Maximum number of functions to trace before diagnosing a hang */
#define GRAPH_MAX_FUNC_TEST 100000000
static void __ftrace_dump(bool disable_tracing);
static unsigned int graph_hang_thresh;
/* Wrap the real function entry probe to avoid possible hanging */
static int trace_graph_entry_watchdog(struct ftrace_graph_ent *trace)
{
/* This is harmlessly racy, we want to approximately detect a hang */
if (unlikely(++graph_hang_thresh > GRAPH_MAX_FUNC_TEST)) {
ftrace_graph_stop();
printk(KERN_WARNING "BUG: Function graph tracer hang!\n");
if (ftrace_dump_on_oops)
__ftrace_dump(false);
return 0;
}
return trace_graph_entry(trace);
}
/*
* Pretty much the same than for the function tracer from which the selftest
* has been borrowed.
*/
int
trace_selftest_startup_function_graph(struct tracer *trace,
struct trace_array *tr)
{
int ret;
unsigned long count;
/*
* Simulate the init() callback but we attach a watchdog callback
* to detect and recover from possible hangs
*/
tracing_reset_online_cpus(tr);
set_graph_array(tr);
ret = register_ftrace_graph(&trace_graph_return,
&trace_graph_entry_watchdog);
if (ret) {
warn_failed_init_tracer(trace, ret);
goto out;
}
tracing_start_cmdline_record();
/* Sleep for a 1/10 of a second */
msleep(100);
/* Have we just recovered from a hang? */
if (graph_hang_thresh > GRAPH_MAX_FUNC_TEST) {
tracing_selftest_disabled = true;
ret = -1;
goto out;
}
tracing_stop();
/* check the trace buffer */
ret = trace_test_buffer(tr, &count);
trace->reset(tr);
tracing_start();
if (!ret && !count) {
printk(KERN_CONT ".. no entries found ..");
ret = -1;
goto out;
}
/* Don't test dynamic tracing, the function tracer already did */
out:
/* Stop it if we failed */
if (ret)
ftrace_graph_stop();
return ret;
}
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
#ifdef CONFIG_IRQSOFF_TRACER
int
trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr)
{
unsigned long save_max = tracing_max_latency;
unsigned long count;
int ret;
/* start the tracing */
ret = tracer_init(trace, tr);
if (ret) {
warn_failed_init_tracer(trace, ret);
return ret;
}
/* reset the max latency */
tracing_max_latency = 0;
/* disable interrupts for a bit */
local_irq_disable();
udelay(100);
local_irq_enable();
tracing/ftrace: stop {irqs, preempt}soff tracers when tracing is stopped Impact: fix a selftest warning In some cases, it's possible to see the following warning on irqsoff tracer selftest: [ 4.640003] Testing tracer irqsoff: <4>------------[ cut here ]------------ [ 4.653562] WARNING: at kernel/trace/trace.c:458 update_max_tr_single+0x9a/0xc4() [ 4.660000] Hardware name: System Product Name [ 4.660000] Modules linked in: [ 4.660000] Pid: 301, comm: kstop/1 Not tainted 2.6.29-rc8-tip #35837 [ 4.660000] Call Trace: [ 4.660000] [<4014b588>] warn_slowpath+0x79/0x8f [ 4.660000] [<402d6949>] ? put_dec+0x64/0x6b [ 4.660000] [<40162b56>] ? getnstimeofday+0x58/0xdd [ 4.660000] [<40162210>] ? clocksource_read+0x3/0xf [ 4.660000] [<4015eb44>] ? ktime_set+0x8/0x34 [ 4.660000] [<4014101a>] ? balance_runtime+0x8/0x56 [ 4.660000] [<405f6f11>] ? _spin_lock+0x3/0x10 [ 4.660000] [<4011f643>] ? ftrace_call+0x5/0x8 [ 4.660000] [<4015d0f1>] ? task_cputime_zero+0x3/0x27 [ 4.660000] [<40190ee7>] ? cpupri_set+0x90/0xcb [ 4.660000] [<405f7208>] ? _spin_lock_irqsave+0x22/0x34 [ 4.660000] [<40190f12>] ? cpupri_set+0xbb/0xcb [ 4.660000] [<405f7151>] ? _spin_unlock_irqrestore+0x23/0x35 [ 4.660000] [<4018493f>] ? ring_buffer_reset_cpu+0x27/0x51 [ 4.660000] [<405f7208>] ? _spin_lock_irqsave+0x22/0x34 [ 4.660000] [<40184962>] ? ring_buffer_reset_cpu+0x4a/0x51 [ 4.660000] [<405f7151>] ? _spin_unlock_irqrestore+0x23/0x35 [ 4.660000] [<4018cc29>] ? trace_hardirqs_off+0x1a/0x1c [ 4.660000] [<405f7151>] ? _spin_unlock_irqrestore+0x23/0x35 [ 4.660000] [<40184962>] ? ring_buffer_reset_cpu+0x4a/0x51 [ 4.660000] [<401850f3>] ? cpumask_next+0x15/0x18 [ 4.660000] [<4018a41f>] update_max_tr_single+0x9a/0xc4 [ 4.660000] [<4014e5fe>] ? exit_notify+0x16/0xf2 [ 4.660000] [<4018cd13>] check_critical_timing+0xcc/0x11e [ 4.660000] [<4014e5fe>] ? exit_notify+0x16/0xf2 [ 4.660000] [<4014e5fe>] ? exit_notify+0x16/0xf2 [ 4.660000] [<4018cdf1>] stop_critical_timing+0x8c/0x9f [ 4.660000] [<4014e5c4>] ? forget_original_parent+0xac/0xd0 [ 4.660000] [<4018ce3a>] trace_hardirqs_on+0x1a/0x1c [ 4.660000] [<4014e5c4>] forget_original_parent+0xac/0xd0 [ 4.660000] [<4014e5fe>] exit_notify+0x16/0xf2 [ 4.660000] [<4014e8a5>] do_exit+0x1cb/0x225 [ 4.660000] [<4015c72b>] ? kthread+0x0/0x69 [ 4.660000] [<4011f61d>] kernel_thread_helper+0xd/0x10 [ 4.660000] ---[ end trace a7919e7f17c0a725 ]--- [ 4.660164] .. no entries found ..FAILED! During the selftest of irqsoff tracer, we do that: /* disable interrupts for a bit */ local_irq_disable(); udelay(100); local_irq_enable(); /* stop the tracing. */ tracing_stop(); /* check both trace buffers */ ret = trace_test_buffer(tr, NULL); If a callsite performs a new max delay with irqs off just after tracing_stop, update_max_tr_single() -> ring_buffer_swap_cpu() will be called with the buffers disabled by tracing_stop(), hence the warning, then ring_buffer_swap_cpu() return -EAGAIN and update_max_tr_single() complains. Fix it by also stopping the tracer before stopping the tracing globally. A similar situation can happen with preemptoff and preemptirqsoff tracers where we apply the same fix. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <1237325938-5240-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-18 05:38:58 +08:00
/*
* Stop the tracer to avoid a warning subsequent
* to buffer flipping failure because tracing_stop()
* disables the tr and max buffers, making flipping impossible
* in case of parallels max irqs off latencies.
*/
trace->stop(tr);
/* stop the tracing. */
tracing_stop();
/* check both trace buffers */
ret = trace_test_buffer(tr, NULL);
if (!ret)
ret = trace_test_buffer(&max_tr, &count);
trace->reset(tr);
tracing_start();
if (!ret && !count) {
printk(KERN_CONT ".. no entries found ..");
ret = -1;
}
tracing_max_latency = save_max;
return ret;
}
#endif /* CONFIG_IRQSOFF_TRACER */
#ifdef CONFIG_PREEMPT_TRACER
int
trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr)
{
unsigned long save_max = tracing_max_latency;
unsigned long count;
int ret;
/*
* Now that the big kernel lock is no longer preemptable,
* and this is called with the BKL held, it will always
* fail. If preemption is already disabled, simply
* pass the test. When the BKL is removed, or becomes
* preemptible again, we will once again test this,
* so keep it in.
*/
if (preempt_count()) {
printk(KERN_CONT "can not test ... force ");
return 0;
}
/* start the tracing */
ret = tracer_init(trace, tr);
if (ret) {
warn_failed_init_tracer(trace, ret);
return ret;
}
/* reset the max latency */
tracing_max_latency = 0;
/* disable preemption for a bit */
preempt_disable();
udelay(100);
preempt_enable();
tracing/ftrace: stop {irqs, preempt}soff tracers when tracing is stopped Impact: fix a selftest warning In some cases, it's possible to see the following warning on irqsoff tracer selftest: [ 4.640003] Testing tracer irqsoff: <4>------------[ cut here ]------------ [ 4.653562] WARNING: at kernel/trace/trace.c:458 update_max_tr_single+0x9a/0xc4() [ 4.660000] Hardware name: System Product Name [ 4.660000] Modules linked in: [ 4.660000] Pid: 301, comm: kstop/1 Not tainted 2.6.29-rc8-tip #35837 [ 4.660000] Call Trace: [ 4.660000] [<4014b588>] warn_slowpath+0x79/0x8f [ 4.660000] [<402d6949>] ? put_dec+0x64/0x6b [ 4.660000] [<40162b56>] ? getnstimeofday+0x58/0xdd [ 4.660000] [<40162210>] ? clocksource_read+0x3/0xf [ 4.660000] [<4015eb44>] ? ktime_set+0x8/0x34 [ 4.660000] [<4014101a>] ? balance_runtime+0x8/0x56 [ 4.660000] [<405f6f11>] ? _spin_lock+0x3/0x10 [ 4.660000] [<4011f643>] ? ftrace_call+0x5/0x8 [ 4.660000] [<4015d0f1>] ? task_cputime_zero+0x3/0x27 [ 4.660000] [<40190ee7>] ? cpupri_set+0x90/0xcb [ 4.660000] [<405f7208>] ? _spin_lock_irqsave+0x22/0x34 [ 4.660000] [<40190f12>] ? cpupri_set+0xbb/0xcb [ 4.660000] [<405f7151>] ? _spin_unlock_irqrestore+0x23/0x35 [ 4.660000] [<4018493f>] ? ring_buffer_reset_cpu+0x27/0x51 [ 4.660000] [<405f7208>] ? _spin_lock_irqsave+0x22/0x34 [ 4.660000] [<40184962>] ? ring_buffer_reset_cpu+0x4a/0x51 [ 4.660000] [<405f7151>] ? _spin_unlock_irqrestore+0x23/0x35 [ 4.660000] [<4018cc29>] ? trace_hardirqs_off+0x1a/0x1c [ 4.660000] [<405f7151>] ? _spin_unlock_irqrestore+0x23/0x35 [ 4.660000] [<40184962>] ? ring_buffer_reset_cpu+0x4a/0x51 [ 4.660000] [<401850f3>] ? cpumask_next+0x15/0x18 [ 4.660000] [<4018a41f>] update_max_tr_single+0x9a/0xc4 [ 4.660000] [<4014e5fe>] ? exit_notify+0x16/0xf2 [ 4.660000] [<4018cd13>] check_critical_timing+0xcc/0x11e [ 4.660000] [<4014e5fe>] ? exit_notify+0x16/0xf2 [ 4.660000] [<4014e5fe>] ? exit_notify+0x16/0xf2 [ 4.660000] [<4018cdf1>] stop_critical_timing+0x8c/0x9f [ 4.660000] [<4014e5c4>] ? forget_original_parent+0xac/0xd0 [ 4.660000] [<4018ce3a>] trace_hardirqs_on+0x1a/0x1c [ 4.660000] [<4014e5c4>] forget_original_parent+0xac/0xd0 [ 4.660000] [<4014e5fe>] exit_notify+0x16/0xf2 [ 4.660000] [<4014e8a5>] do_exit+0x1cb/0x225 [ 4.660000] [<4015c72b>] ? kthread+0x0/0x69 [ 4.660000] [<4011f61d>] kernel_thread_helper+0xd/0x10 [ 4.660000] ---[ end trace a7919e7f17c0a725 ]--- [ 4.660164] .. no entries found ..FAILED! During the selftest of irqsoff tracer, we do that: /* disable interrupts for a bit */ local_irq_disable(); udelay(100); local_irq_enable(); /* stop the tracing. */ tracing_stop(); /* check both trace buffers */ ret = trace_test_buffer(tr, NULL); If a callsite performs a new max delay with irqs off just after tracing_stop, update_max_tr_single() -> ring_buffer_swap_cpu() will be called with the buffers disabled by tracing_stop(), hence the warning, then ring_buffer_swap_cpu() return -EAGAIN and update_max_tr_single() complains. Fix it by also stopping the tracer before stopping the tracing globally. A similar situation can happen with preemptoff and preemptirqsoff tracers where we apply the same fix. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <1237325938-5240-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-18 05:38:58 +08:00
/*
* Stop the tracer to avoid a warning subsequent
* to buffer flipping failure because tracing_stop()
* disables the tr and max buffers, making flipping impossible
* in case of parallels max preempt off latencies.
*/
trace->stop(tr);
/* stop the tracing. */
tracing_stop();
/* check both trace buffers */
ret = trace_test_buffer(tr, NULL);
if (!ret)
ret = trace_test_buffer(&max_tr, &count);
trace->reset(tr);
tracing_start();
if (!ret && !count) {
printk(KERN_CONT ".. no entries found ..");
ret = -1;
}
tracing_max_latency = save_max;
return ret;
}
#endif /* CONFIG_PREEMPT_TRACER */
#if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
int
trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *tr)
{
unsigned long save_max = tracing_max_latency;
unsigned long count;
int ret;
/*
* Now that the big kernel lock is no longer preemptable,
* and this is called with the BKL held, it will always
* fail. If preemption is already disabled, simply
* pass the test. When the BKL is removed, or becomes
* preemptible again, we will once again test this,
* so keep it in.
*/
if (preempt_count()) {
printk(KERN_CONT "can not test ... force ");
return 0;
}
/* start the tracing */
ret = tracer_init(trace, tr);
if (ret) {
warn_failed_init_tracer(trace, ret);
tracing/ftrace: fix double calls to tracing_start() Impact: fix a warning during preemptirqsoff selftests When the preemptirqsoff selftest fails, we see the following warning: [ 6.050000] Testing tracer preemptirqsoff: .. no entries found .. ------------[ cut here ]------------ [ 6.060000] WARNING: at kernel/trace/trace.c:688 tracing_start+0x67/0xd3() [ 6.060000] Modules linked in: [ 6.060000] Pid: 1, comm: swapper Tainted: G [ 6.060000] Call Trace: [ 6.060000] [<ffffffff802460ff>] warn_slowpath+0xb1/0x100 [ 6.060000] [<ffffffff802a8f5b>] ? trace_preempt_on+0x35/0x4b [ 6.060000] [<ffffffff802a37fb>] ? tracing_start+0x31/0xd3 [ 6.060000] [<ffffffff802a37fb>] ? tracing_start+0x31/0xd3 [ 6.060000] [<ffffffff80271e0b>] ? __lock_acquired+0xe6/0x1f2 [ 6.060000] [<ffffffff802a37fb>] ? tracing_start+0x31/0xd3 [ 6.060000] [<ffffffff802a3831>] tracing_start+0x67/0xd3 [ 6.060000] [<ffffffff802a8ace>] ? irqsoff_tracer_reset+0x2d/0x57 [ 6.060000] [<ffffffff802a4d1c>] trace_selftest_startup_preemptirqsoff+0x1c8/0x1f1 [ 6.060000] [<ffffffff802a4798>] register_tracer+0x12f/0x241 [ 6.060000] [<ffffffff810250d0>] ? init_irqsoff_tracer+0x0/0x53 [ 6.060000] [<ffffffff8102510b>] init_irqsoff_tracer+0x3b/0x53 This is because in fail case, the preemptirqsoff tracer selftest calls twice the tracing_start() function: int trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *tr) { if (!ret && !count) { printk(KERN_CONT ".. no entries found .."); ret = -1; tracing_start(); <----- goto out; } [...] out: trace->reset(tr); tracing_start(); <------ tracing_max_latency = save_max; return ret; } Since it is well handled in the out path, we don't need the conditional one. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <1237159961-7447-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-16 07:32:41 +08:00
goto out_no_start;
}
/* reset the max latency */
tracing_max_latency = 0;
/* disable preemption and interrupts for a bit */
preempt_disable();
local_irq_disable();
udelay(100);
preempt_enable();
/* reverse the order of preempt vs irqs */
local_irq_enable();
tracing/ftrace: stop {irqs, preempt}soff tracers when tracing is stopped Impact: fix a selftest warning In some cases, it's possible to see the following warning on irqsoff tracer selftest: [ 4.640003] Testing tracer irqsoff: <4>------------[ cut here ]------------ [ 4.653562] WARNING: at kernel/trace/trace.c:458 update_max_tr_single+0x9a/0xc4() [ 4.660000] Hardware name: System Product Name [ 4.660000] Modules linked in: [ 4.660000] Pid: 301, comm: kstop/1 Not tainted 2.6.29-rc8-tip #35837 [ 4.660000] Call Trace: [ 4.660000] [<4014b588>] warn_slowpath+0x79/0x8f [ 4.660000] [<402d6949>] ? put_dec+0x64/0x6b [ 4.660000] [<40162b56>] ? getnstimeofday+0x58/0xdd [ 4.660000] [<40162210>] ? clocksource_read+0x3/0xf [ 4.660000] [<4015eb44>] ? ktime_set+0x8/0x34 [ 4.660000] [<4014101a>] ? balance_runtime+0x8/0x56 [ 4.660000] [<405f6f11>] ? _spin_lock+0x3/0x10 [ 4.660000] [<4011f643>] ? ftrace_call+0x5/0x8 [ 4.660000] [<4015d0f1>] ? task_cputime_zero+0x3/0x27 [ 4.660000] [<40190ee7>] ? cpupri_set+0x90/0xcb [ 4.660000] [<405f7208>] ? _spin_lock_irqsave+0x22/0x34 [ 4.660000] [<40190f12>] ? cpupri_set+0xbb/0xcb [ 4.660000] [<405f7151>] ? _spin_unlock_irqrestore+0x23/0x35 [ 4.660000] [<4018493f>] ? ring_buffer_reset_cpu+0x27/0x51 [ 4.660000] [<405f7208>] ? _spin_lock_irqsave+0x22/0x34 [ 4.660000] [<40184962>] ? ring_buffer_reset_cpu+0x4a/0x51 [ 4.660000] [<405f7151>] ? _spin_unlock_irqrestore+0x23/0x35 [ 4.660000] [<4018cc29>] ? trace_hardirqs_off+0x1a/0x1c [ 4.660000] [<405f7151>] ? _spin_unlock_irqrestore+0x23/0x35 [ 4.660000] [<40184962>] ? ring_buffer_reset_cpu+0x4a/0x51 [ 4.660000] [<401850f3>] ? cpumask_next+0x15/0x18 [ 4.660000] [<4018a41f>] update_max_tr_single+0x9a/0xc4 [ 4.660000] [<4014e5fe>] ? exit_notify+0x16/0xf2 [ 4.660000] [<4018cd13>] check_critical_timing+0xcc/0x11e [ 4.660000] [<4014e5fe>] ? exit_notify+0x16/0xf2 [ 4.660000] [<4014e5fe>] ? exit_notify+0x16/0xf2 [ 4.660000] [<4018cdf1>] stop_critical_timing+0x8c/0x9f [ 4.660000] [<4014e5c4>] ? forget_original_parent+0xac/0xd0 [ 4.660000] [<4018ce3a>] trace_hardirqs_on+0x1a/0x1c [ 4.660000] [<4014e5c4>] forget_original_parent+0xac/0xd0 [ 4.660000] [<4014e5fe>] exit_notify+0x16/0xf2 [ 4.660000] [<4014e8a5>] do_exit+0x1cb/0x225 [ 4.660000] [<4015c72b>] ? kthread+0x0/0x69 [ 4.660000] [<4011f61d>] kernel_thread_helper+0xd/0x10 [ 4.660000] ---[ end trace a7919e7f17c0a725 ]--- [ 4.660164] .. no entries found ..FAILED! During the selftest of irqsoff tracer, we do that: /* disable interrupts for a bit */ local_irq_disable(); udelay(100); local_irq_enable(); /* stop the tracing. */ tracing_stop(); /* check both trace buffers */ ret = trace_test_buffer(tr, NULL); If a callsite performs a new max delay with irqs off just after tracing_stop, update_max_tr_single() -> ring_buffer_swap_cpu() will be called with the buffers disabled by tracing_stop(), hence the warning, then ring_buffer_swap_cpu() return -EAGAIN and update_max_tr_single() complains. Fix it by also stopping the tracer before stopping the tracing globally. A similar situation can happen with preemptoff and preemptirqsoff tracers where we apply the same fix. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <1237325938-5240-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-18 05:38:58 +08:00
/*
* Stop the tracer to avoid a warning subsequent
* to buffer flipping failure because tracing_stop()
* disables the tr and max buffers, making flipping impossible
* in case of parallels max irqs/preempt off latencies.
*/
trace->stop(tr);
/* stop the tracing. */
tracing_stop();
/* check both trace buffers */
ret = trace_test_buffer(tr, NULL);
tracing/ftrace: fix double calls to tracing_start() Impact: fix a warning during preemptirqsoff selftests When the preemptirqsoff selftest fails, we see the following warning: [ 6.050000] Testing tracer preemptirqsoff: .. no entries found .. ------------[ cut here ]------------ [ 6.060000] WARNING: at kernel/trace/trace.c:688 tracing_start+0x67/0xd3() [ 6.060000] Modules linked in: [ 6.060000] Pid: 1, comm: swapper Tainted: G [ 6.060000] Call Trace: [ 6.060000] [<ffffffff802460ff>] warn_slowpath+0xb1/0x100 [ 6.060000] [<ffffffff802a8f5b>] ? trace_preempt_on+0x35/0x4b [ 6.060000] [<ffffffff802a37fb>] ? tracing_start+0x31/0xd3 [ 6.060000] [<ffffffff802a37fb>] ? tracing_start+0x31/0xd3 [ 6.060000] [<ffffffff80271e0b>] ? __lock_acquired+0xe6/0x1f2 [ 6.060000] [<ffffffff802a37fb>] ? tracing_start+0x31/0xd3 [ 6.060000] [<ffffffff802a3831>] tracing_start+0x67/0xd3 [ 6.060000] [<ffffffff802a8ace>] ? irqsoff_tracer_reset+0x2d/0x57 [ 6.060000] [<ffffffff802a4d1c>] trace_selftest_startup_preemptirqsoff+0x1c8/0x1f1 [ 6.060000] [<ffffffff802a4798>] register_tracer+0x12f/0x241 [ 6.060000] [<ffffffff810250d0>] ? init_irqsoff_tracer+0x0/0x53 [ 6.060000] [<ffffffff8102510b>] init_irqsoff_tracer+0x3b/0x53 This is because in fail case, the preemptirqsoff tracer selftest calls twice the tracing_start() function: int trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *tr) { if (!ret && !count) { printk(KERN_CONT ".. no entries found .."); ret = -1; tracing_start(); <----- goto out; } [...] out: trace->reset(tr); tracing_start(); <------ tracing_max_latency = save_max; return ret; } Since it is well handled in the out path, we don't need the conditional one. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <1237159961-7447-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-16 07:32:41 +08:00
if (ret)
goto out;
ret = trace_test_buffer(&max_tr, &count);
tracing/ftrace: fix double calls to tracing_start() Impact: fix a warning during preemptirqsoff selftests When the preemptirqsoff selftest fails, we see the following warning: [ 6.050000] Testing tracer preemptirqsoff: .. no entries found .. ------------[ cut here ]------------ [ 6.060000] WARNING: at kernel/trace/trace.c:688 tracing_start+0x67/0xd3() [ 6.060000] Modules linked in: [ 6.060000] Pid: 1, comm: swapper Tainted: G [ 6.060000] Call Trace: [ 6.060000] [<ffffffff802460ff>] warn_slowpath+0xb1/0x100 [ 6.060000] [<ffffffff802a8f5b>] ? trace_preempt_on+0x35/0x4b [ 6.060000] [<ffffffff802a37fb>] ? tracing_start+0x31/0xd3 [ 6.060000] [<ffffffff802a37fb>] ? tracing_start+0x31/0xd3 [ 6.060000] [<ffffffff80271e0b>] ? __lock_acquired+0xe6/0x1f2 [ 6.060000] [<ffffffff802a37fb>] ? tracing_start+0x31/0xd3 [ 6.060000] [<ffffffff802a3831>] tracing_start+0x67/0xd3 [ 6.060000] [<ffffffff802a8ace>] ? irqsoff_tracer_reset+0x2d/0x57 [ 6.060000] [<ffffffff802a4d1c>] trace_selftest_startup_preemptirqsoff+0x1c8/0x1f1 [ 6.060000] [<ffffffff802a4798>] register_tracer+0x12f/0x241 [ 6.060000] [<ffffffff810250d0>] ? init_irqsoff_tracer+0x0/0x53 [ 6.060000] [<ffffffff8102510b>] init_irqsoff_tracer+0x3b/0x53 This is because in fail case, the preemptirqsoff tracer selftest calls twice the tracing_start() function: int trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *tr) { if (!ret && !count) { printk(KERN_CONT ".. no entries found .."); ret = -1; tracing_start(); <----- goto out; } [...] out: trace->reset(tr); tracing_start(); <------ tracing_max_latency = save_max; return ret; } Since it is well handled in the out path, we don't need the conditional one. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <1237159961-7447-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-16 07:32:41 +08:00
if (ret)
goto out;
if (!ret && !count) {
printk(KERN_CONT ".. no entries found ..");
ret = -1;
goto out;
}
/* do the test by disabling interrupts first this time */
tracing_max_latency = 0;
tracing_start();
tracing/ftrace: stop {irqs, preempt}soff tracers when tracing is stopped Impact: fix a selftest warning In some cases, it's possible to see the following warning on irqsoff tracer selftest: [ 4.640003] Testing tracer irqsoff: <4>------------[ cut here ]------------ [ 4.653562] WARNING: at kernel/trace/trace.c:458 update_max_tr_single+0x9a/0xc4() [ 4.660000] Hardware name: System Product Name [ 4.660000] Modules linked in: [ 4.660000] Pid: 301, comm: kstop/1 Not tainted 2.6.29-rc8-tip #35837 [ 4.660000] Call Trace: [ 4.660000] [<4014b588>] warn_slowpath+0x79/0x8f [ 4.660000] [<402d6949>] ? put_dec+0x64/0x6b [ 4.660000] [<40162b56>] ? getnstimeofday+0x58/0xdd [ 4.660000] [<40162210>] ? clocksource_read+0x3/0xf [ 4.660000] [<4015eb44>] ? ktime_set+0x8/0x34 [ 4.660000] [<4014101a>] ? balance_runtime+0x8/0x56 [ 4.660000] [<405f6f11>] ? _spin_lock+0x3/0x10 [ 4.660000] [<4011f643>] ? ftrace_call+0x5/0x8 [ 4.660000] [<4015d0f1>] ? task_cputime_zero+0x3/0x27 [ 4.660000] [<40190ee7>] ? cpupri_set+0x90/0xcb [ 4.660000] [<405f7208>] ? _spin_lock_irqsave+0x22/0x34 [ 4.660000] [<40190f12>] ? cpupri_set+0xbb/0xcb [ 4.660000] [<405f7151>] ? _spin_unlock_irqrestore+0x23/0x35 [ 4.660000] [<4018493f>] ? ring_buffer_reset_cpu+0x27/0x51 [ 4.660000] [<405f7208>] ? _spin_lock_irqsave+0x22/0x34 [ 4.660000] [<40184962>] ? ring_buffer_reset_cpu+0x4a/0x51 [ 4.660000] [<405f7151>] ? _spin_unlock_irqrestore+0x23/0x35 [ 4.660000] [<4018cc29>] ? trace_hardirqs_off+0x1a/0x1c [ 4.660000] [<405f7151>] ? _spin_unlock_irqrestore+0x23/0x35 [ 4.660000] [<40184962>] ? ring_buffer_reset_cpu+0x4a/0x51 [ 4.660000] [<401850f3>] ? cpumask_next+0x15/0x18 [ 4.660000] [<4018a41f>] update_max_tr_single+0x9a/0xc4 [ 4.660000] [<4014e5fe>] ? exit_notify+0x16/0xf2 [ 4.660000] [<4018cd13>] check_critical_timing+0xcc/0x11e [ 4.660000] [<4014e5fe>] ? exit_notify+0x16/0xf2 [ 4.660000] [<4014e5fe>] ? exit_notify+0x16/0xf2 [ 4.660000] [<4018cdf1>] stop_critical_timing+0x8c/0x9f [ 4.660000] [<4014e5c4>] ? forget_original_parent+0xac/0xd0 [ 4.660000] [<4018ce3a>] trace_hardirqs_on+0x1a/0x1c [ 4.660000] [<4014e5c4>] forget_original_parent+0xac/0xd0 [ 4.660000] [<4014e5fe>] exit_notify+0x16/0xf2 [ 4.660000] [<4014e8a5>] do_exit+0x1cb/0x225 [ 4.660000] [<4015c72b>] ? kthread+0x0/0x69 [ 4.660000] [<4011f61d>] kernel_thread_helper+0xd/0x10 [ 4.660000] ---[ end trace a7919e7f17c0a725 ]--- [ 4.660164] .. no entries found ..FAILED! During the selftest of irqsoff tracer, we do that: /* disable interrupts for a bit */ local_irq_disable(); udelay(100); local_irq_enable(); /* stop the tracing. */ tracing_stop(); /* check both trace buffers */ ret = trace_test_buffer(tr, NULL); If a callsite performs a new max delay with irqs off just after tracing_stop, update_max_tr_single() -> ring_buffer_swap_cpu() will be called with the buffers disabled by tracing_stop(), hence the warning, then ring_buffer_swap_cpu() return -EAGAIN and update_max_tr_single() complains. Fix it by also stopping the tracer before stopping the tracing globally. A similar situation can happen with preemptoff and preemptirqsoff tracers where we apply the same fix. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <1237325938-5240-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-18 05:38:58 +08:00
trace->start(tr);
preempt_disable();
local_irq_disable();
udelay(100);
preempt_enable();
/* reverse the order of preempt vs irqs */
local_irq_enable();
tracing/ftrace: stop {irqs, preempt}soff tracers when tracing is stopped Impact: fix a selftest warning In some cases, it's possible to see the following warning on irqsoff tracer selftest: [ 4.640003] Testing tracer irqsoff: <4>------------[ cut here ]------------ [ 4.653562] WARNING: at kernel/trace/trace.c:458 update_max_tr_single+0x9a/0xc4() [ 4.660000] Hardware name: System Product Name [ 4.660000] Modules linked in: [ 4.660000] Pid: 301, comm: kstop/1 Not tainted 2.6.29-rc8-tip #35837 [ 4.660000] Call Trace: [ 4.660000] [<4014b588>] warn_slowpath+0x79/0x8f [ 4.660000] [<402d6949>] ? put_dec+0x64/0x6b [ 4.660000] [<40162b56>] ? getnstimeofday+0x58/0xdd [ 4.660000] [<40162210>] ? clocksource_read+0x3/0xf [ 4.660000] [<4015eb44>] ? ktime_set+0x8/0x34 [ 4.660000] [<4014101a>] ? balance_runtime+0x8/0x56 [ 4.660000] [<405f6f11>] ? _spin_lock+0x3/0x10 [ 4.660000] [<4011f643>] ? ftrace_call+0x5/0x8 [ 4.660000] [<4015d0f1>] ? task_cputime_zero+0x3/0x27 [ 4.660000] [<40190ee7>] ? cpupri_set+0x90/0xcb [ 4.660000] [<405f7208>] ? _spin_lock_irqsave+0x22/0x34 [ 4.660000] [<40190f12>] ? cpupri_set+0xbb/0xcb [ 4.660000] [<405f7151>] ? _spin_unlock_irqrestore+0x23/0x35 [ 4.660000] [<4018493f>] ? ring_buffer_reset_cpu+0x27/0x51 [ 4.660000] [<405f7208>] ? _spin_lock_irqsave+0x22/0x34 [ 4.660000] [<40184962>] ? ring_buffer_reset_cpu+0x4a/0x51 [ 4.660000] [<405f7151>] ? _spin_unlock_irqrestore+0x23/0x35 [ 4.660000] [<4018cc29>] ? trace_hardirqs_off+0x1a/0x1c [ 4.660000] [<405f7151>] ? _spin_unlock_irqrestore+0x23/0x35 [ 4.660000] [<40184962>] ? ring_buffer_reset_cpu+0x4a/0x51 [ 4.660000] [<401850f3>] ? cpumask_next+0x15/0x18 [ 4.660000] [<4018a41f>] update_max_tr_single+0x9a/0xc4 [ 4.660000] [<4014e5fe>] ? exit_notify+0x16/0xf2 [ 4.660000] [<4018cd13>] check_critical_timing+0xcc/0x11e [ 4.660000] [<4014e5fe>] ? exit_notify+0x16/0xf2 [ 4.660000] [<4014e5fe>] ? exit_notify+0x16/0xf2 [ 4.660000] [<4018cdf1>] stop_critical_timing+0x8c/0x9f [ 4.660000] [<4014e5c4>] ? forget_original_parent+0xac/0xd0 [ 4.660000] [<4018ce3a>] trace_hardirqs_on+0x1a/0x1c [ 4.660000] [<4014e5c4>] forget_original_parent+0xac/0xd0 [ 4.660000] [<4014e5fe>] exit_notify+0x16/0xf2 [ 4.660000] [<4014e8a5>] do_exit+0x1cb/0x225 [ 4.660000] [<4015c72b>] ? kthread+0x0/0x69 [ 4.660000] [<4011f61d>] kernel_thread_helper+0xd/0x10 [ 4.660000] ---[ end trace a7919e7f17c0a725 ]--- [ 4.660164] .. no entries found ..FAILED! During the selftest of irqsoff tracer, we do that: /* disable interrupts for a bit */ local_irq_disable(); udelay(100); local_irq_enable(); /* stop the tracing. */ tracing_stop(); /* check both trace buffers */ ret = trace_test_buffer(tr, NULL); If a callsite performs a new max delay with irqs off just after tracing_stop, update_max_tr_single() -> ring_buffer_swap_cpu() will be called with the buffers disabled by tracing_stop(), hence the warning, then ring_buffer_swap_cpu() return -EAGAIN and update_max_tr_single() complains. Fix it by also stopping the tracer before stopping the tracing globally. A similar situation can happen with preemptoff and preemptirqsoff tracers where we apply the same fix. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <1237325938-5240-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-18 05:38:58 +08:00
trace->stop(tr);
/* stop the tracing. */
tracing_stop();
/* check both trace buffers */
ret = trace_test_buffer(tr, NULL);
if (ret)
goto out;
ret = trace_test_buffer(&max_tr, &count);
if (!ret && !count) {
printk(KERN_CONT ".. no entries found ..");
ret = -1;
goto out;
}
tracing/ftrace: fix double calls to tracing_start() Impact: fix a warning during preemptirqsoff selftests When the preemptirqsoff selftest fails, we see the following warning: [ 6.050000] Testing tracer preemptirqsoff: .. no entries found .. ------------[ cut here ]------------ [ 6.060000] WARNING: at kernel/trace/trace.c:688 tracing_start+0x67/0xd3() [ 6.060000] Modules linked in: [ 6.060000] Pid: 1, comm: swapper Tainted: G [ 6.060000] Call Trace: [ 6.060000] [<ffffffff802460ff>] warn_slowpath+0xb1/0x100 [ 6.060000] [<ffffffff802a8f5b>] ? trace_preempt_on+0x35/0x4b [ 6.060000] [<ffffffff802a37fb>] ? tracing_start+0x31/0xd3 [ 6.060000] [<ffffffff802a37fb>] ? tracing_start+0x31/0xd3 [ 6.060000] [<ffffffff80271e0b>] ? __lock_acquired+0xe6/0x1f2 [ 6.060000] [<ffffffff802a37fb>] ? tracing_start+0x31/0xd3 [ 6.060000] [<ffffffff802a3831>] tracing_start+0x67/0xd3 [ 6.060000] [<ffffffff802a8ace>] ? irqsoff_tracer_reset+0x2d/0x57 [ 6.060000] [<ffffffff802a4d1c>] trace_selftest_startup_preemptirqsoff+0x1c8/0x1f1 [ 6.060000] [<ffffffff802a4798>] register_tracer+0x12f/0x241 [ 6.060000] [<ffffffff810250d0>] ? init_irqsoff_tracer+0x0/0x53 [ 6.060000] [<ffffffff8102510b>] init_irqsoff_tracer+0x3b/0x53 This is because in fail case, the preemptirqsoff tracer selftest calls twice the tracing_start() function: int trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *tr) { if (!ret && !count) { printk(KERN_CONT ".. no entries found .."); ret = -1; tracing_start(); <----- goto out; } [...] out: trace->reset(tr); tracing_start(); <------ tracing_max_latency = save_max; return ret; } Since it is well handled in the out path, we don't need the conditional one. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <1237159961-7447-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-16 07:32:41 +08:00
out:
tracing_start();
tracing/ftrace: fix double calls to tracing_start() Impact: fix a warning during preemptirqsoff selftests When the preemptirqsoff selftest fails, we see the following warning: [ 6.050000] Testing tracer preemptirqsoff: .. no entries found .. ------------[ cut here ]------------ [ 6.060000] WARNING: at kernel/trace/trace.c:688 tracing_start+0x67/0xd3() [ 6.060000] Modules linked in: [ 6.060000] Pid: 1, comm: swapper Tainted: G [ 6.060000] Call Trace: [ 6.060000] [<ffffffff802460ff>] warn_slowpath+0xb1/0x100 [ 6.060000] [<ffffffff802a8f5b>] ? trace_preempt_on+0x35/0x4b [ 6.060000] [<ffffffff802a37fb>] ? tracing_start+0x31/0xd3 [ 6.060000] [<ffffffff802a37fb>] ? tracing_start+0x31/0xd3 [ 6.060000] [<ffffffff80271e0b>] ? __lock_acquired+0xe6/0x1f2 [ 6.060000] [<ffffffff802a37fb>] ? tracing_start+0x31/0xd3 [ 6.060000] [<ffffffff802a3831>] tracing_start+0x67/0xd3 [ 6.060000] [<ffffffff802a8ace>] ? irqsoff_tracer_reset+0x2d/0x57 [ 6.060000] [<ffffffff802a4d1c>] trace_selftest_startup_preemptirqsoff+0x1c8/0x1f1 [ 6.060000] [<ffffffff802a4798>] register_tracer+0x12f/0x241 [ 6.060000] [<ffffffff810250d0>] ? init_irqsoff_tracer+0x0/0x53 [ 6.060000] [<ffffffff8102510b>] init_irqsoff_tracer+0x3b/0x53 This is because in fail case, the preemptirqsoff tracer selftest calls twice the tracing_start() function: int trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *tr) { if (!ret && !count) { printk(KERN_CONT ".. no entries found .."); ret = -1; tracing_start(); <----- goto out; } [...] out: trace->reset(tr); tracing_start(); <------ tracing_max_latency = save_max; return ret; } Since it is well handled in the out path, we don't need the conditional one. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <1237159961-7447-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-16 07:32:41 +08:00
out_no_start:
trace->reset(tr);
tracing_max_latency = save_max;
return ret;
}
#endif /* CONFIG_IRQSOFF_TRACER && CONFIG_PREEMPT_TRACER */
#ifdef CONFIG_NOP_TRACER
int
trace_selftest_startup_nop(struct tracer *trace, struct trace_array *tr)
{
/* What could possibly go wrong? */
return 0;
}
#endif
#ifdef CONFIG_SCHED_TRACER
static int trace_wakeup_test_thread(void *data)
{
/* Make this a RT thread, doesn't need to be too high */
struct sched_param param = { .sched_priority = 5 };
struct completion *x = data;
sched_setscheduler(current, SCHED_FIFO, &param);
/* Make it know we have a new prio */
complete(x);
/* now go to sleep and let the test wake us up */
set_current_state(TASK_INTERRUPTIBLE);
schedule();
/* we are awake, now wait to disappear */
while (!kthread_should_stop()) {
/*
* This is an RT task, do short sleeps to let
* others run.
*/
msleep(100);
}
return 0;
}
int
trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
{
unsigned long save_max = tracing_max_latency;
struct task_struct *p;
struct completion isrt;
unsigned long count;
int ret;
init_completion(&isrt);
/* create a high prio thread */
p = kthread_run(trace_wakeup_test_thread, &isrt, "ftrace-test");
if (IS_ERR(p)) {
printk(KERN_CONT "Failed to create ftrace wakeup test thread ");
return -1;
}
/* make sure the thread is running at an RT prio */
wait_for_completion(&isrt);
/* start the tracing */
ret = tracer_init(trace, tr);
if (ret) {
warn_failed_init_tracer(trace, ret);
return ret;
}
/* reset the max latency */
tracing_max_latency = 0;
/* sleep to let the RT thread sleep too */
msleep(100);
/*
* Yes this is slightly racy. It is possible that for some
* strange reason that the RT thread we created, did not
* call schedule for 100ms after doing the completion,
* and we do a wakeup on a task that already is awake.
* But that is extremely unlikely, and the worst thing that
* happens in such a case, is that we disable tracing.
* Honestly, if this race does happen something is horrible
* wrong with the system.
*/
wake_up_process(p);
/* give a little time to let the thread wake up */
msleep(100);
/* stop the tracing. */
tracing_stop();
/* check both trace buffers */
ret = trace_test_buffer(tr, NULL);
if (!ret)
ret = trace_test_buffer(&max_tr, &count);
trace->reset(tr);
tracing_start();
tracing_max_latency = save_max;
/* kill the thread */
kthread_stop(p);
if (!ret && !count) {
printk(KERN_CONT ".. no entries found ..");
ret = -1;
}
return ret;
}
#endif /* CONFIG_SCHED_TRACER */
#ifdef CONFIG_CONTEXT_SWITCH_TRACER
int
trace_selftest_startup_sched_switch(struct tracer *trace, struct trace_array *tr)
{
unsigned long count;
int ret;
/* start the tracing */
ret = tracer_init(trace, tr);
if (ret) {
warn_failed_init_tracer(trace, ret);
return ret;
}
/* Sleep for a 1/10 of a second */
msleep(100);
/* stop the tracing. */
tracing_stop();
/* check the trace buffer */
ret = trace_test_buffer(tr, &count);
trace->reset(tr);
tracing_start();
if (!ret && !count) {
printk(KERN_CONT ".. no entries found ..");
ret = -1;
}
return ret;
}
#endif /* CONFIG_CONTEXT_SWITCH_TRACER */
#ifdef CONFIG_SYSPROF_TRACER
int
trace_selftest_startup_sysprof(struct tracer *trace, struct trace_array *tr)
{
unsigned long count;
int ret;
/* start the tracing */
ret = tracer_init(trace, tr);
if (ret) {
warn_failed_init_tracer(trace, ret);
return ret;
}
/* Sleep for a 1/10 of a second */
msleep(100);
/* stop the tracing. */
tracing_stop();
/* check the trace buffer */
ret = trace_test_buffer(tr, &count);
trace->reset(tr);
tracing_start();
if (!ret && !count) {
printk(KERN_CONT ".. no entries found ..");
ret = -1;
}
return ret;
}
#endif /* CONFIG_SYSPROF_TRACER */
#ifdef CONFIG_BRANCH_TRACER
int
trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr)
{
unsigned long count;
int ret;
/* start the tracing */
ret = tracer_init(trace, tr);
if (ret) {
warn_failed_init_tracer(trace, ret);
return ret;
}
/* Sleep for a 1/10 of a second */
msleep(100);
/* stop the tracing. */
tracing_stop();
/* check the trace buffer */
ret = trace_test_buffer(tr, &count);
trace->reset(tr);
tracing_start();
if (!ret && !count) {
printk(KERN_CONT ".. no entries found ..");
ret = -1;
}
return ret;
}
#endif /* CONFIG_BRANCH_TRACER */
#ifdef CONFIG_HW_BRANCH_TRACER
int
trace_selftest_startup_hw_branches(struct tracer *trace,
struct trace_array *tr)
{
struct trace_iterator *iter;
struct tracer tracer;
unsigned long count;
int ret;
if (!trace->open) {
printk(KERN_CONT "missing open function...");
return -1;
}
ret = tracer_init(trace, tr);
if (ret) {
warn_failed_init_tracer(trace, ret);
return ret;
}
/*
* The hw-branch tracer needs to collect the trace from the various
* cpu trace buffers - before tracing is stopped.
*/
iter = kzalloc(sizeof(*iter), GFP_KERNEL);
if (!iter)
return -ENOMEM;
memcpy(&tracer, trace, sizeof(tracer));
iter->trace = &tracer;
iter->tr = tr;
iter->pos = -1;
mutex_init(&iter->mutex);
trace->open(iter);
mutex_destroy(&iter->mutex);
kfree(iter);
tracing_stop();
ret = trace_test_buffer(tr, &count);
trace->reset(tr);
tracing_start();
if (!ret && !count) {
printk(KERN_CONT "no entries found..");
ret = -1;
}
return ret;
}
#endif /* CONFIG_HW_BRANCH_TRACER */
#ifdef CONFIG_KSYM_TRACER
static int ksym_selftest_dummy;
int
trace_selftest_startup_ksym(struct tracer *trace, struct trace_array *tr)
{
unsigned long count;
int ret;
/* start the tracing */
ret = tracer_init(trace, tr);
if (ret) {
warn_failed_init_tracer(trace, ret);
return ret;
}
ksym_selftest_dummy = 0;
/* Register the read-write tracing request */
hw-breakpoints: Rewrite the hw-breakpoints layer on top of perf events This patch rebase the implementation of the breakpoints API on top of perf events instances. Each breakpoints are now perf events that handle the register scheduling, thread/cpu attachment, etc.. The new layering is now made as follows: ptrace kgdb ftrace perf syscall \ | / / \ | / / / Core breakpoint API / / | / | / Breakpoints perf events | | Breakpoints PMU ---- Debug Register constraints handling (Part of core breakpoint API) | | Hardware debug registers Reasons of this rewrite: - Use the centralized/optimized pmu registers scheduling, implying an easier arch integration - More powerful register handling: perf attributes (pinned/flexible events, exclusive/non-exclusive, tunable period, etc...) Impact: - New perf ABI: the hardware breakpoints counters - Ptrace breakpoints setting remains tricky and still needs some per thread breakpoints references. Todo (in the order): - Support breakpoints perf counter events for perf tools (ie: implement perf_bpcounter_event()) - Support from perf tools Changes in v2: - Follow the perf "event " rename - The ptrace regression have been fixed (ptrace breakpoint perf events weren't released when a task ended) - Drop the struct hw_breakpoint and store generic fields in perf_event_attr. - Separate core and arch specific headers, drop asm-generic/hw_breakpoint.h and create linux/hw_breakpoint.h - Use new generic len/type for breakpoint - Handle off case: when breakpoints api is not supported by an arch Changes in v3: - Fix broken CONFIG_KVM, we need to propagate the breakpoint api changes to kvm when we exit the guest and restore the bp registers to the host. Changes in v4: - Drop the hw_breakpoint_restore() stub as it is only used by KVM - EXPORT_SYMBOL_GPL hw_breakpoint_restore() as KVM can be built as a module - Restore the breakpoints unconditionally on kvm guest exit: TIF_DEBUG_THREAD doesn't anymore cover every cases of running breakpoints and vcpu->arch.switch_db_regs might not always be set when the guest used debug registers. (Waiting for a reliable optimization) Changes in v5: - Split-up the asm-generic/hw-breakpoint.h moving to linux/hw_breakpoint.h into a separate patch - Optimize the breakpoints restoring while switching from kvm guest to host. We only want to restore the state if we have active breakpoints to the host, otherwise we don't care about messed-up address registers. - Add asm/hw_breakpoint.h to Kbuild - Fix bad breakpoint type in trace_selftest.c Changes in v6: - Fix wrong header inclusion in trace.h (triggered a build error with CONFIG_FTRACE_SELFTEST Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jan Kiszka <jan.kiszka@web.de> Cc: Jiri Slaby <jirislaby@gmail.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Avi Kivity <avi@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Paul Mundt <lethal@linux-sh.org>
2009-09-10 01:22:48 +08:00
ret = process_new_ksym_entry(KSYM_SELFTEST_ENTRY,
HW_BREAKPOINT_R | HW_BREAKPOINT_W,
(unsigned long)(&ksym_selftest_dummy));
if (ret < 0) {
printk(KERN_CONT "ksym_trace read-write startup test failed\n");
goto ret_path;
}
/* Perform a read and a write operation over the dummy variable to
* trigger the tracer
*/
if (ksym_selftest_dummy == 0)
ksym_selftest_dummy++;
/* stop the tracing. */
tracing_stop();
/* check the trace buffer */
ret = trace_test_buffer(tr, &count);
trace->reset(tr);
tracing_start();
/* read & write operations - one each is performed on the dummy variable
* triggering two entries in the trace buffer
*/
if (!ret && count != 2) {
printk(KERN_CONT "Ksym tracer startup test failed");
ret = -1;
}
ret_path:
return ret;
}
#endif /* CONFIG_KSYM_TRACER */