#include <linux/kallsyms.h>
#include <linux/security.h>
#include <linux/seq_file.h>
-#include <linux/notifier.h>
#include <linux/irqflags.h>
#include <linux/debugfs.h>
#include <linux/tracefs.h>
#endif
/* Pipe tracepoints to printk */
-struct trace_iterator *tracepoint_print_iter;
+static struct trace_iterator *tracepoint_print_iter;
int tracepoint_printk;
static bool tracepoint_printk_stop_on_boot __initdata;
static DEFINE_STATIC_KEY_FALSE(tracepoint_printk_key);
/* ring_buffer_unlock_commit() enables preemption */
preempt_enable_notrace();
} else
- ring_buffer_unlock_commit(buffer, event);
+ ring_buffer_unlock_commit(buffer);
}
/**
return false;
}
EXPORT_SYMBOL_GPL(tracing_snapshot_cond_disable);
+#define free_snapshot(tr) do { } while (0)
#endif /* CONFIG_TRACER_SNAPSHOT */
void tracer_tracing_off(struct trace_array *tr)
}
unsigned long __read_mostly tracing_thresh;
+
+#ifdef CONFIG_TRACER_MAX_TRACE
static const struct file_operations tracing_max_lat_fops;
#ifdef LATENCY_FS_NOTIFY
irq_work_queue(&tr->fsnotify_irqwork);
}
-#elif defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER) \
- || defined(CONFIG_OSNOISE_TRACER)
+#else /* !LATENCY_FS_NOTIFY */
#define trace_create_maxlat_file(tr, d_tracer) \
trace_create_file("tracing_max_latency", TRACE_MODE_WRITE, \
d_tracer, &tr->max_latency, &tracing_max_lat_fops)
-#else
-#define trace_create_maxlat_file(tr, d_tracer) do { } while (0)
#endif
-#ifdef CONFIG_TRACER_MAX_TRACE
/*
* Copy the new maximum trace into the separate maximum-trace
* structure. (this way the maximum trace is permanently saved,
ring_buffer_record_off(tr->max_buffer.buffer);
#ifdef CONFIG_TRACER_SNAPSHOT
- if (tr->cond_snapshot && !tr->cond_snapshot->update(tr, cond_data))
- goto out_unlock;
+ if (tr->cond_snapshot && !tr->cond_snapshot->update(tr, cond_data)) {
+ arch_spin_unlock(&tr->max_lock);
+ return;
+ }
#endif
swap(tr->array_buffer.buffer, tr->max_buffer.buffer);
__update_max_tr(tr, tsk, cpu);
- out_unlock:
arch_spin_unlock(&tr->max_lock);
}
__update_max_tr(tr, tsk, cpu);
arch_spin_unlock(&tr->max_lock);
}
+
#endif /* CONFIG_TRACER_MAX_TRACE */
static int wait_on_pipe(struct trace_iterator *iter, int full)
}
/* Must have trace_types_lock held */
-void tracing_reset_all_online_cpus(void)
+void tracing_reset_all_online_cpus_unlocked(void)
{
struct trace_array *tr;
+ lockdep_assert_held(&trace_types_lock);
+
list_for_each_entry(tr, &ftrace_trace_arrays, list) {
if (!tr->clear_trace)
continue;
}
}
+void tracing_reset_all_online_cpus(void)
+{
+ mutex_lock(&trace_types_lock);
+ tracing_reset_all_online_cpus_unlocked();
+ mutex_unlock(&trace_types_lock);
+}
+
/*
* The tgid_map array maps from pid to tgid; i.e. the value stored at index i
* is the tgid last observed corresponding to pid=i.
"\t [:size=#entries]\n"
"\t [:pause][:continue][:clear]\n"
"\t [:name=histname1]\n"
+ "\t [:nohitcount]\n"
"\t [:<handler>.<action>]\n"
"\t [if <filter>]\n\n"
"\t Note, special fields can be used as well:\n"
"\t .syscall display a syscall id as a syscall name\n"
"\t .log2 display log2 value rather than raw number\n"
"\t .buckets=size display values in groups of size rather than raw number\n"
- "\t .usecs display a common_timestamp in microseconds\n\n"
+ "\t .usecs display a common_timestamp in microseconds\n"
+ "\t .percent display a number of percentage value\n"
+ "\t .graph display a bar-graph of a value\n\n"
"\t The 'pause' parameter can be used to pause an existing hist\n"
"\t trigger or to start a hist trigger but not log any events\n"
"\t until told to do so. 'continue' can be used to start or\n"
"\t The 'clear' parameter will clear the contents of a running\n"
"\t hist trigger and leave its current paused/active state\n"
"\t unchanged.\n\n"
+ "\t The 'nohitcount' (or NOHC) parameter will suppress display of\n"
+ "\t raw hitcount in the histogram.\n\n"
"\t The enable_hist and disable_hist triggers can be used to\n"
"\t have one event conditionally start and stop another event's\n"
"\t already-attached hist trigger. The syntax is analogous to\n"
return ret;
}
-#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
+#ifdef CONFIG_TRACER_MAX_TRACE
static ssize_t
tracing_max_lat_read(struct file *filp, char __user *ubuf,
mutex_unlock(&trace_types_lock);
free_cpumask_var(iter->started);
+ kfree(iter->fmt);
mutex_destroy(&iter->mutex);
kfree(iter);
ret = print_trace_line(iter);
if (ret == TRACE_TYPE_PARTIAL_LINE) {
- /* don't print partial lines */
+ /*
+ * If one print_trace_line() fills entire trace_seq in one shot,
+ * trace_seq_to_user() will returns -EBUSY because save_len == 0,
+ * In this case, we need to consume it, otherwise, loop will peek
+ * this event next time, resulting in an infinite loop.
+ */
+ if (save_len == 0) {
+ iter->seq.full = 0;
+ trace_seq_puts(&iter->seq, "[LINE TOO BIG]\n");
+ trace_consume(iter);
+ break;
+ }
+
+ /* In other cases, don't print partial lines */
iter->seq.seq.len = save_len;
break;
}
.llseek = generic_file_llseek,
};
-#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
+#ifdef CONFIG_TRACER_MAX_TRACE
static const struct file_operations tracing_max_lat_fops = {
.open = tracing_open_generic,
.read = tracing_max_lat_read,
int len)
{
struct tracing_log_err *err;
+ char *cmd;
if (tr->n_err_log_entries < TRACING_LOG_ERRS_MAX) {
err = alloc_tracing_log_err(len);
return err;
}
-
+ cmd = kzalloc(len, GFP_KERNEL);
+ if (!cmd)
+ return ERR_PTR(-ENOMEM);
err = list_first_entry(&tr->err_log, struct tracing_log_err, list);
kfree(err->cmd);
- err->cmd = kzalloc(len, GFP_KERNEL);
- if (!err->cmd)
- return ERR_PTR(-ENOMEM);
+ err->cmd = cmd;
list_del(&err->list);
return err;
create_trace_options_dir(tr);
+#ifdef CONFIG_TRACER_MAX_TRACE
trace_create_maxlat_file(tr, d_tracer);
+#endif
if (ftrace_create_function_files(tr, d_tracer))
MEM_FAIL(1, "Could not allocate function filter files");
fs_initcall(tracer_init_tracefs);
-static int trace_panic_handler(struct notifier_block *this,
- unsigned long event, void *unused)
-{
- if (ftrace_dump_on_oops)
- ftrace_dump(ftrace_dump_on_oops);
- return NOTIFY_OK;
-}
+static int trace_die_panic_handler(struct notifier_block *self,
+ unsigned long ev, void *unused);
static struct notifier_block trace_panic_notifier = {
- .notifier_call = trace_panic_handler,
- .next = NULL,
- .priority = 150 /* priority: INT_MAX >= x >= 0 */
+ .notifier_call = trace_die_panic_handler,
+ .priority = INT_MAX - 1,
};
-static int trace_die_handler(struct notifier_block *self,
- unsigned long val,
- void *data)
-{
- switch (val) {
- case DIE_OOPS:
- if (ftrace_dump_on_oops)
- ftrace_dump(ftrace_dump_on_oops);
- break;
- default:
- break;
- }
- return NOTIFY_OK;
-}
-
static struct notifier_block trace_die_notifier = {
- .notifier_call = trace_die_handler,
- .priority = 200
+ .notifier_call = trace_die_panic_handler,
+ .priority = INT_MAX - 1,
};
+/*
+ * The idea is to execute the following die/panic callback early, in order
+ * to avoid showing irrelevant information in the trace (like other panic
+ * notifier functions); we are the 2nd to run, after hung_task/rcu_stall
+ * warnings get disabled (to prevent potential log flooding).
+ */
+static int trace_die_panic_handler(struct notifier_block *self,
+ unsigned long ev, void *unused)
+{
+ if (!ftrace_dump_on_oops)
+ return NOTIFY_DONE;
+
+ /* The die notifier requires DIE_OOPS to trigger */
+ if (self == &trace_die_notifier && ev != DIE_OOPS)
+ return NOTIFY_DONE;
+
+ ftrace_dump(ftrace_dump_on_oops);
+
+ return NOTIFY_DONE;
+}
+
/*
* printk is set to max of 1024, we really don't need it that big.
* Nothing should be printing 1000 characters anyway.
git.samba.org / sfrench / cifs-2.6.git / blobdiff