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Diffstat (limited to 'kernel/trace/trace.c')
-rw-r--r--kernel/trace/trace.c99
1 files changed, 70 insertions, 29 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 60f3b6289731..756d7283318b 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -117,9 +117,12 @@ static cpumask_var_t __read_mostly tracing_buffer_mask;
*
* It is default off, but you can enable it with either specifying
* "ftrace_dump_on_oops" in the kernel command line, or setting
- * /proc/sys/kernel/ftrace_dump_on_oops to true.
+ * /proc/sys/kernel/ftrace_dump_on_oops
+ * Set 1 if you want to dump buffers of all CPUs
+ * Set 2 if you want to dump the buffer of the CPU that triggered oops
*/
-int ftrace_dump_on_oops;
+
+enum ftrace_dump_mode ftrace_dump_on_oops;
static int tracing_set_tracer(const char *buf);
@@ -139,8 +142,17 @@ __setup("ftrace=", set_cmdline_ftrace);
static int __init set_ftrace_dump_on_oops(char *str)
{
- ftrace_dump_on_oops = 1;
- return 1;
+ if (*str++ != '=' || !*str) {
+ ftrace_dump_on_oops = DUMP_ALL;
+ return 1;
+ }
+
+ if (!strcmp("orig_cpu", str)) {
+ ftrace_dump_on_oops = DUMP_ORIG;
+ return 1;
+ }
+
+ return 0;
}
__setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops);
@@ -1571,7 +1583,7 @@ __find_next_entry(struct trace_iterator *iter, int *ent_cpu,
{
struct ring_buffer *buffer = iter->tr->buffer;
struct trace_entry *ent, *next = NULL;
- unsigned long lost_events, next_lost = 0;
+ unsigned long lost_events = 0, next_lost = 0;
int cpu_file = iter->cpu_file;
u64 next_ts = 0, ts;
int next_cpu = -1;
@@ -1796,7 +1808,7 @@ static void print_func_help_header(struct seq_file *m)
}
-static void
+void
print_trace_header(struct seq_file *m, struct trace_iterator *iter)
{
unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
@@ -2005,7 +2017,7 @@ static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
return event ? event->binary(iter, 0) : TRACE_TYPE_HANDLED;
}
-static int trace_empty(struct trace_iterator *iter)
+int trace_empty(struct trace_iterator *iter)
{
int cpu;
@@ -2072,6 +2084,23 @@ static enum print_line_t print_trace_line(struct trace_iterator *iter)
return print_trace_fmt(iter);
}
+void trace_default_header(struct seq_file *m)
+{
+ struct trace_iterator *iter = m->private;
+
+ if (iter->iter_flags & TRACE_FILE_LAT_FMT) {
+ /* print nothing if the buffers are empty */
+ if (trace_empty(iter))
+ return;
+ print_trace_header(m, iter);
+ if (!(trace_flags & TRACE_ITER_VERBOSE))
+ print_lat_help_header(m);
+ } else {
+ if (!(trace_flags & TRACE_ITER_VERBOSE))
+ print_func_help_header(m);
+ }
+}
+
static int s_show(struct seq_file *m, void *v)
{
struct trace_iterator *iter = v;
@@ -2084,17 +2113,9 @@ static int s_show(struct seq_file *m, void *v)
}
if (iter->trace && iter->trace->print_header)
iter->trace->print_header(m);
- else if (iter->iter_flags & TRACE_FILE_LAT_FMT) {
- /* print nothing if the buffers are empty */
- if (trace_empty(iter))
- return 0;
- print_trace_header(m, iter);
- if (!(trace_flags & TRACE_ITER_VERBOSE))
- print_lat_help_header(m);
- } else {
- if (!(trace_flags & TRACE_ITER_VERBOSE))
- print_func_help_header(m);
- }
+ else
+ trace_default_header(m);
+
} else if (iter->leftover) {
/*
* If we filled the seq_file buffer earlier, we
@@ -2180,15 +2201,20 @@ __tracing_open(struct inode *inode, struct file *file)
if (iter->cpu_file == TRACE_PIPE_ALL_CPU) {
for_each_tracing_cpu(cpu) {
-
iter->buffer_iter[cpu] =
- ring_buffer_read_start(iter->tr->buffer, cpu);
+ ring_buffer_read_prepare(iter->tr->buffer, cpu);
+ }
+ ring_buffer_read_prepare_sync();
+ for_each_tracing_cpu(cpu) {
+ ring_buffer_read_start(iter->buffer_iter[cpu]);
tracing_iter_reset(iter, cpu);
}
} else {
cpu = iter->cpu_file;
iter->buffer_iter[cpu] =
- ring_buffer_read_start(iter->tr->buffer, cpu);
+ ring_buffer_read_prepare(iter->tr->buffer, cpu);
+ ring_buffer_read_prepare_sync();
+ ring_buffer_read_start(iter->buffer_iter[cpu]);
tracing_iter_reset(iter, cpu);
}
@@ -4338,7 +4364,7 @@ static int trace_panic_handler(struct notifier_block *this,
unsigned long event, void *unused)
{
if (ftrace_dump_on_oops)
- ftrace_dump();
+ ftrace_dump(ftrace_dump_on_oops);
return NOTIFY_OK;
}
@@ -4355,7 +4381,7 @@ static int trace_die_handler(struct notifier_block *self,
switch (val) {
case DIE_OOPS:
if (ftrace_dump_on_oops)
- ftrace_dump();
+ ftrace_dump(ftrace_dump_on_oops);
break;
default:
break;
@@ -4396,7 +4422,8 @@ trace_printk_seq(struct trace_seq *s)
trace_seq_init(s);
}
-static void __ftrace_dump(bool disable_tracing)
+static void
+__ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode)
{
static arch_spinlock_t ftrace_dump_lock =
(arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
@@ -4429,12 +4456,25 @@ static void __ftrace_dump(bool disable_tracing)
/* don't look at user memory in panic mode */
trace_flags &= ~TRACE_ITER_SYM_USEROBJ;
- printk(KERN_TRACE "Dumping ftrace buffer:\n");
-
/* Simulate the iterator */
iter.tr = &global_trace;
iter.trace = current_trace;
- iter.cpu_file = TRACE_PIPE_ALL_CPU;
+
+ switch (oops_dump_mode) {
+ case DUMP_ALL:
+ iter.cpu_file = TRACE_PIPE_ALL_CPU;
+ break;
+ case DUMP_ORIG:
+ iter.cpu_file = raw_smp_processor_id();
+ break;
+ case DUMP_NONE:
+ goto out_enable;
+ default:
+ printk(KERN_TRACE "Bad dumping mode, switching to all CPUs dump\n");
+ iter.cpu_file = TRACE_PIPE_ALL_CPU;
+ }
+
+ printk(KERN_TRACE "Dumping ftrace buffer:\n");
/*
* We need to stop all tracing on all CPUS to read the
@@ -4473,6 +4513,7 @@ static void __ftrace_dump(bool disable_tracing)
else
printk(KERN_TRACE "---------------------------------\n");
+ out_enable:
/* Re-enable tracing if requested */
if (!disable_tracing) {
trace_flags |= old_userobj;
@@ -4489,9 +4530,9 @@ static void __ftrace_dump(bool disable_tracing)
}
/* By default: disable tracing after the dump */
-void ftrace_dump(void)
+void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
{
- __ftrace_dump(true);
+ __ftrace_dump(true, oops_dump_mode);
}
__init static int tracer_alloc_buffers(void)