From d2ef7c2f0f9ab48c25eafc0ebad0df5f7930420b Mon Sep 17 00:00:00 2001 From: Wenji Huang Date: Tue, 17 Feb 2009 01:09:47 -0500 Subject: tracing: fix the return value of trace selftest This patch is to fix the return value of trace_selftest_startup_sysprof and trace_selftest_startup_branch on failure. Signed-off-by: Wenji Huang Signed-off-by: Steven Rostedt --- kernel/trace/trace_selftest.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) (limited to 'kernel/trace/trace_selftest.c') diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 0c9aa1457e51..c72e749bcbef 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -622,7 +622,7 @@ trace_selftest_startup_sysprof(struct tracer *trace, struct trace_array *tr) ret = tracer_init(trace, tr); if (ret) { warn_failed_init_tracer(trace, ret); - return 0; + return ret; } /* Sleep for a 1/10 of a second */ @@ -634,6 +634,11 @@ trace_selftest_startup_sysprof(struct tracer *trace, struct trace_array *tr) trace->reset(tr); tracing_start(); + if (!ret && !count) { + printk(KERN_CONT ".. no entries found .."); + ret = -1; + } + return ret; } #endif /* CONFIG_SYSPROF_TRACER */ @@ -661,6 +666,11 @@ trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr) trace->reset(tr); tracing_start(); + if (!ret && !count) { + printk(KERN_CONT ".. no entries found .."); + ret = -1; + } + return ret; } #endif /* CONFIG_BRANCH_TRACER */ -- cgit v1.2.3 From 73d8b8bc4f24a97a406d09c8268ac019f4ac661e Mon Sep 17 00:00:00 2001 From: Wenji Huang Date: Tue, 17 Feb 2009 01:10:02 -0500 Subject: tracing: fix typing mistake in hint message and comments Impact: cleanup Fix incorrect hint message in code and typos in comments. Signed-off-by: Wenji Huang Signed-off-by: Steven Rostedt --- kernel/trace/trace_irqsoff.c | 2 +- kernel/trace/trace_sched_switch.c | 2 +- kernel/trace/trace_sched_wakeup.c | 2 +- kernel/trace/trace_selftest.c | 4 ++-- kernel/trace/trace_stat.c | 2 +- kernel/trace/trace_sysprof.c | 2 +- 6 files changed, 7 insertions(+), 7 deletions(-) (limited to 'kernel/trace/trace_selftest.c') diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index c6b442d88de8..9e5ebd844158 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -1,5 +1,5 @@ /* - * trace irqs off criticall timings + * trace irqs off critical timings * * Copyright (C) 2007-2008 Steven Rostedt * Copyright (C) 2008 Ingo Molnar diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c index 30e14fe85896..82fbb5a2df89 100644 --- a/kernel/trace/trace_sched_switch.c +++ b/kernel/trace/trace_sched_switch.c @@ -93,7 +93,7 @@ static int tracing_sched_register(void) ret = register_trace_sched_switch(probe_sched_switch); if (ret) { pr_info("sched trace: Couldn't activate tracepoint" - " probe to kernel_sched_schedule\n"); + " probe to kernel_sched_switch\n"); goto fail_deprobe_wake_new; } diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index 96d716485898..276c51aaf314 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -284,7 +284,7 @@ static void start_wakeup_tracer(struct trace_array *tr) ret = register_trace_sched_switch(probe_wakeup_sched_switch); if (ret) { pr_info("sched trace: Couldn't activate tracepoint" - " probe to kernel_sched_schedule\n"); + " probe to kernel_sched_switch\n"); goto fail_deprobe_wake_new; } diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index c72e749bcbef..01415f4edaa5 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -107,9 +107,9 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace, func(); /* - * Some archs *cough*PowerPC*cough* add charachters to the + * Some archs *cough*PowerPC*cough* add characters to the * start of the function names. We simply put a '*' to - * accomodate them. + * accommodate them. */ func_name = "*" STR(DYN_FTRACE_TEST_NAME); diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c index eae9cef39291..39310e3434ee 100644 --- a/kernel/trace/trace_stat.c +++ b/kernel/trace/trace_stat.c @@ -30,7 +30,7 @@ struct tracer_stat_session { struct dentry *file; }; -/* All of the sessions currently in use. Each stat file embeed one session */ +/* All of the sessions currently in use. Each stat file embed one session */ static LIST_HEAD(all_stat_sessions); static DEFINE_MUTEX(all_stat_sessions_mutex); diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c index 7c9a2d82a7d8..c771af4e8f1a 100644 --- a/kernel/trace/trace_sysprof.c +++ b/kernel/trace/trace_sysprof.c @@ -327,5 +327,5 @@ void init_tracer_sysprof_debugfs(struct dentry *d_tracer) d_tracer, NULL, &sysprof_sample_fops); if (entry) return; - pr_warning("Could not create debugfs 'dyn_ftrace_total_info' entry\n"); + pr_warning("Could not create debugfs 'sysprof_sample_period' entry\n"); } -- cgit v1.2.3 From 0c5119c1e655e0719a69601b1049acdd5ec1c125 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 18 Feb 2009 18:33:57 -0500 Subject: tracing: disable tracing while testing ring buffer Impact: fix to prevent hard lockup on self tests If one of the tracers are broken and is constantly filling the ring buffer while the test of the ring buffer is running, it will hang the box. The reason is that the test is a consumer that will not stop till the ring buffer is empty. But if the tracer is broken and is constantly producing input to the buffer, this test will never end. The result is a lockup of the box. This happened when KALLSYMS was not defined and the dynamic ftrace test constantly filled the ring buffer, because the filter failed and all functions were being traced. Something was being called that constantly filled the buffer. Signed-off-by: Steven Rostedt --- kernel/trace/trace_selftest.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'kernel/trace/trace_selftest.c') diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 88c8eb70f54a..a7e0ef662f9f 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -57,11 +57,20 @@ static int trace_test_buffer(struct trace_array *tr, unsigned long *count) 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); -- cgit v1.2.3 From 4b3e3d228429c75d398f1aa24532e468d3220c49 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 18 Feb 2009 22:50:01 -0500 Subject: tracing: limit the number of loops the ring buffer self test can make Impact: prevent deadlock if ring buffer gets corrupted This patch adds a paranoid check to make sure the ring buffer consumer does not go into an infinite loop. Since the ring buffer has been set to read only, the consumer should not loop for more than the ring buffer size. A check is added to make sure the consumer does not loop more than the ring buffer size. Signed-off-by: Steven Rostedt --- kernel/trace/trace_selftest.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'kernel/trace/trace_selftest.c') diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index a7e0ef662f9f..bc8e80a86bca 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -23,10 +23,20 @@ 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); -- cgit v1.2.3